Title of Invention	"FRONT-REAR INTERLOCKED BRAKE APPARATUS FOR VEHICLE"
Abstract	A front-rear interlocked brake system of a simple construction produces only a rear wheel braking force in an initial stage of a braking operation, produces both a rear wheel braking force and a front wheel braking force as brake operating force increases beyond a predetermined value for front-rear interlocked braking operation. [CONSTITUTION] A braking characteristic setting spring (91) is disposed between a component part of an interlocking brake operating force transmitting system (41) capable of applying a brake operating force corresponding to an operation of a rear brake operating member (71) to a front brake (BF1), and a fixed member fixed to the body of a vehicle, to apply a force to the interlocking brake operating force transmitting system (41) in a direction opposite a direction in which the rear brake operating member (71) applies a force to the interlocking brake operating force transmitting system (41). [SELECTED DRAWING] Fig. 1

Title of Invention

"FRONT-REAR INTERLOCKED BRAKE APPARATUS FOR VEHICLE"

Abstract

A front-rear interlocked brake system of a simple construction produces only a rear wheel braking force in an initial stage of a braking operation, produces both a rear wheel braking force and a front wheel braking force as brake operating force increases beyond a predetermined value for front-rear interlocked braking operation. [CONSTITUTION] A braking characteristic setting spring (91) is disposed between a component part of an interlocking brake operating force transmitting system (41) capable of applying a brake operating force corresponding to an operation of a rear brake operating member (71) to a front brake (BF1), and a fixed member fixed to the body of a vehicle, to apply a force to the interlocking brake operating force transmitting system (41) in a direction opposite a direction in which the rear brake operating member (71) applies a force to the interlocking brake operating force transmitting system (41). [SELECTED DRAWING] Fig. 1

Full Text	[DETAILED DESCRIPTION OF THE INVENTION] [0 0 0 1] [Technical Field of the Invention] The present invention relates to a front-rear interlocked brake system for a vehicle, comprising a front brake operating member to be operated to operate a front brake, and a rear brake operating member capable of operating both the front brake and a rear brake when operated and, more particularly, to a front-rear interlocked brake system suitable for use on a motorcycle. [0 0 0 2] [Related Art] Interlocked front-rear brake systems have been disclosed in, for example, JP-B No. 47-3298 and JP-A No. 50-53842. [0 0 0 3] [Problem to be Solved by the Invention] In the foregoing known interlocked front-rear brake systems, a reaction force of a rear brake operated by a brake applying operation of a rear brake operating member is transmitted to a front brake to apply both the front brake and the rear brake. However, the known interlocked front-rear brake systems have a complicated construction. Fig. 21 shows a previously proposed interlocked front-rear brake system of a simple construction. Referring to Fig, 21, a liquid pressure produced by a front brake master cylinder MF operated by a front brake operating member 6' is applied to a front disk brake BF', a liquid pressure produced by a rear brake master cylinder MR operated by a rear brake operating member 7' is applied through a proportional control valve V to a rear disk brake BR ', and an interlocking cable 10' is connected to the rear brake operating member 7' and the front brake operating member 6' so that only the brake operating force of the rear brake operating member 7' can be transmitted to the front brake operating member 6'. In this known interlocked front-rear brake system, the front brake operating member 6' operates upon the brake applying operation of the rear brake operating member 7', so that the front and the rear brake are applied immediately after the operation of the rear brake operating member 7'. [0 0 0 4] The present invention has been made in view of the foregoing circumstances and it is therefore an object of the present invention to provide a front-rear interlocked brake system for a vehicle, having a simple construction for the interlocked operation of a front brake and a rear-brake, and capable of making only the rear brake operate in an initial stage of application of a brake operating force and making both the rear brake and the front brake operate after the increase of the brake operating force beyond a predetermined value. [0 0 0 5] [Means for Solving the Problem] With the foregoing object in view, according to an invention stated in claim 1, a front-rear interlocked brake system for a vehicle, comprises: a front brake operating member to apply a front brake in response to a brake applying operation; and a rear brake operating member capable of applying both a rear brake and the front brake. The interlocked front-rear brake system is provided with a component member of an interlocking brake operating force transmitting system capable of transmitting a brake operating force applied to the rear brake operating member to the front brake; a fixed member fixed to a body, and a braking characteristic setting spring for applying a force acting in a direction opposite the direction in which the rear brake operating member applies a force to the interlocking brake operating force transmitting system, disposed between the component member of the interlocking brake operating force transmitting system, and the fixed member. [0 0 0 6] According to the invention stated in claim 2, in the interlocked front-rear brake system stated in claim 1, the rear brake operating member is connected to a substantially middle portion of an equalizer, one end of the interlocking brake operating force transmitting system and one end of a rear brake operating force transmitting member connected to the rear brake are connected to opposite end portions of the equalizer, respectively, and the equalizer is capable of turning on the joint of the equalizer and the interlocking brake operating force transmitting system which exerts a brake operating force through the rear wheel braking force transmitting member on the rear brake when the brake operating force of the rear brake operating member is less than a force corresponding to the force of the braking characteristic setting spring, and of driving the front brake through the interlocking brake operating force transmitting system and driving the rear brake through the rear wheel braking force transmitting member when the brake operating force of the rear brake operating member is not lower than a force corresponding to the force of the braking characteristic setting spring. [0 0 0 7] According to an invention stated in claim 3, in the front-rear interlocked brake system for a vehicle, according to claim 2, the rear brake operating member is connected by a connecting member to the equalizer, and the connecting member is provided with a stopper that engages with the equalizer in a direction to stop the turning of the equalizer on a joint of the equalizer and the connecting member in a direction to reduce the force transmitted through the rear brake operating force transmitting member. [0 0 0 8] According to an invention stated in claim 4, in the front-rear interlocked brake system for a vehicle, according to claim 3, the interlocking brake operating force transmitting system has an interlocking cable having one end connected to the equalizer and the other end connected to the front brake operating member, and capable of transmitting a brake operating force from the rear brake operating member to the front brake operating member. [0 0 0 9] According to an invention stated in claim 5, in the front-rear interlocked brake system for a vehicle, according to claim 2, the rear brake operating member is a brake pedal, the rear brake operating member is connected to a substantially middle portion of the equalizer, the interlocking brake operating force transmitting system is connected to one end of the equalizer, and the mechanical rear brake is connected through the rear wheel braking force transmitting member to the other end of the equalizer. [0 0 10] According to an invention stated in claim 6, in the front-rear interlocked brake system for a vehicle, according to claim 2, the interlocking brake operating force transmitting system is provided with an interlocking master cylinder interlocked with the equalizer and capable of producing a liquid pressure to be applied to the hydraulic front brake. [0 0 11] According to an invention stated in claim 7, in the front-rear interlocked brake system for a vehicle, according to claim 6, the hydraulic front brake is a disk brake comprising a first caliper piston operated by a liquid pressure produced by a front master cylinder according to the operation of the front brake operating member, and a second caliper piston operated by a liquid pressure produced by the interlocking master cylinder. [0 0 12] According to an invention stated in claim 8, in the front-rear interlocked brake system for a vehicle, according to claim 6, the interlocking master cylinder is connected to a hydraulic system interconnecting a liquid pressure chamber in which the master piston of a front master cylinder operated by the front brake operating member is placed and the front brake so as to inhibit the exertion of a liquid pressure produced in the liquid pressure chamber by the master piston on the interlocking master cylinder. [0 0 13] According to an invention stated in claim 9, in the front-rear interlocked brake system for a vehicle, according to claim 5, the interlocking brake operating force transmitting system comprises an interlocking cable having one end connected to the equalizer, and a front master cylinder which produces a liquid pressure to be applied to the hydraulic front brake when operated by pulling the interlocking cable or the operation of the front brake operating member. [BRIEF DESCRIPTION OF THE DRAWINGS] [Fig. 1] Fig. 1 is a view showing the general arrangement of a front-rear interlocked brake system in a first embodiment according to the present invention. [Fig. 2] Fig. 2 is a partly sectional plan view of a right end portion of a handlebar included in a motorcycle. [Fig. 3] Fig. 3 is an enlarged sectional view taken on line 3-3 in Fig. 2. [Fig. 4] Fig. 4 is a partly cut away plan view of a left end portion of the handlebar of the motorcycle. [Fig. 5] Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 4. [Fig. 6] Fig. 6 is view of the right and the left end portion of the handlebar in a state where only a front brake operating member is operated. [Fig. 7] Fig. 7 is a graph showing the characteristics of front and rear wheel braking forces. [Fig. 8] Fig. 8 is a view of the right and the left end portion of the handlebar in a state where only a rear brake operating member is operated to apply the rear brake. [Fig. 9] Fig. 9 is a view of the right and the left end portion of the handlebar in a state where only the rear brake operating member is operated to apply both the front and the rear brake for the front-rear interlocked braking operation. [Fig. 10] Fig. 10 is a view of the right and the left end portion of the handlebar in a state where both the front and the rear brake operating member are operated. [Fig. 11] Fig. 11 is a view showing the general arrangement of a front-rear interlocked brake system in a second embodiment according to the present invention. [Fig. 12] Fig. 12 is a partly sectional view of a left end portion of a handlebar included in a front-rear interlocked brake system in a third embodiment according to the present invention. [Fig. 13] Fig. 13 is a sectional view taken on line 13-13 in Fig. 12. [Fig. 14] Fig. 14 is a sectional view taken on line 14-14 in Fig. 12. [Fig. 15] Fig. 15 is a sectional view taken on line 15-15 in Fig. 12. [Fig. 16] Fig. 16 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a fourth embodiment according to the present invention. [Fig. 17] Fig. 17 is an enlarged longitudinal sectional view of a rear brake operating member and an interlocking master cylinder. [Fig. 18] Fig. 18 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a fifth embodiment according to the present invention. [Fig. 19] Fig. 19 is an enlarged longitudinal sectional view of a front master cylinder. [Fig. 20] Fig. 20 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a sixth embodiment according to the present invention. [Fig. 21] Fig. 21 is a view showing the general arrangement of a prior art front-rear interlocked brake system. [0 0 14] [Description of the Preferred Embodiments] Preferred embodiments of the present invention will be described hereinafter with reference to the accompanying drawings. [0 0 15] Figs. 1 to 10 show a front-rear interlocked brake system in a first embodiment according to the present invention as applied to a motor scooter, in which Fig. 1 is a view showing the general arrangement of the front-rear interlocked brake system, Fig. 2 is a partly sectional plan view of a right end portion of a handlebar included in the motor scooter, Fig. 3 is an enlarged sectional view taken on line 3-3 in Fig. 2, Fig. 4 is a partly cut away plan view of a left end portion of the handlebar of the motor, scooter, Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 4, Fig. 6 is view of the right and the left end portion of the handlebar in a state where only a front brake operating member is operated, Fig. 7 is a graph showing the characteristics of front and rear wheel braking forces, Fig. 8 is a view of the right and the left end portion of the handlebar in a state where only a rear brake operating member is operated to apply the rear brake, Fig. 9 is a view of the right and the left end portion of the handlebar in a state where only the rear brake operating member is operated to apply both the front and the rear brake for the front-rear interlocked braking operation, and Fig. 10 is a view of the right and the left end portion of the handlebar in a state where both the front and the rear brake operating member are operated. [0 0 16] Referring to Fig. 1, the front-rear interlocked brake system has hydraulic front brake BF1, a front brake lever 61r i.e., a front brake operating member, for applying the hydraulic front brake BF1, a mechanical rear brake BR1, and a rear brake lever 7, by which both the front brake BF1 and the rear brake BR1 can simultaneously be applied. [0 0 17] The rear brake lever 71 is connected to a substantially middle portion of an equalizer 121, and one end of an interlocking brake operating force transmitting system 41 and one end of a rear brake cable 11, i.e., a rear wheel braking force transmitting member, connected to the rear brake BR1 are connected to opposite end portions of the equalizer 12l, respectively. [0 0 18] The interlocking brake operating force transmitting system 4i includes an interlocking cable 10 having one end connected to the equalizer 121, and an auxiliary brake operating member 81 connected to the other end of the interlocking cable 10 and capable of engaging with the front brake lever 6a from the brake releasing side of the front brake lever 6j. The interlocking cable 10 is biased by a braking characteristic setting spring 9a in a direction to disengage the auxiliary brake operating member 8a from the front brake lever 61. [0 0 19] The front brake Bri is a disk brake having a brake caliper 13, and a master cylinder 14 formed integrally with the brake caliper 13. A brake operating force is applied to a brake arm 15 associated with the master cylinder 14 and the master cylinder 14 produces a liquid pressure according to the brake operating force to produce a braking force. The rear brake BR1 is a drum brake comprising a brake drum 17 mounted on a rear axle 16, a brake panel 18, a pair of brake shoes 20 pivotally supported by a pin 19 on the brake panel 18 and capable of being brought into frictional contact with the inner circumference of the brake drum 17, a pair of springs 21 biasing the pair of brake shoes 20 toward each other, a brake cam 22 supported for turning on the brake panel 18 to operate the pair of brake shoes 20 so that the pair of brake shoes 20 are pressed against the inner circumference of the brake drum 17, and a brake arm 23 having a base end connected to the brake cam 22 and extending outside from the brake drum 17. The rear brake BRI produces a braking force according to a brake operating force applied to the brake arm 23. [0 0 2 0] Referring to Figs. 2 and 3, a grip 26 to be grasped by the driver's right hand is attached to a right end portion of a handlebar 25 provided in a front portion of the body of the motor scooter. An upper holder 27 and a lower holder 28 are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 26 and are fastened together and fixed to the handlebar 25 with a pair of bolts 29. The front brake lever 61 is supported for turning at its base end by a shaft 30 on a substantially U-shaped bracket 28a formed integrally with the lower holder 28. The front brake lever 61 is operated for a braking operation by the right hand gripping the grip 26. [0 0 2 1] A first support part 28b is formed integrally with the lower holder 28 opposite to the base end of the front brake lever 61. One end of the sheath 31a of a front brake cable 31 is fixed to the first support part 28b. A cable 31b sheathed in the sheath 31a has one end connected to the base end of the front brake lever 61 The other end of the front brake cable 31 is connected to the brake arm 15 of the front brake BF1 as shown in Fig.l. When the front brake lever 61 is operated for braking, the front brake BF1 is applied. [0 0 2 2] A lower end portion of the shaft 30 project downward from the bracket 28a, and the auxiliary brake operating member 81 is supported for turning on the lower end portion of the shaft 30. The auxiliary brake operating member 81 is provided integrally in one end portion thereof with a working portion 8a which engages with the front brake lever 61 from the side of the first support part 28b of the lower holder 28, i.e., the brake releasing side of the front brake lever 61. A connecting member 33 is connected to the other end portion of the auxiliary brake operating member 81 with a connecting pin 32 fitted in a through hole formed in the other end portion of the auxiliary brake operating member 81 with its axis in parallel to that of the shaft 30. A second support part 28c is formed integrally with the lower holder 28 at a position spaced from the connecting member 33. The other end of the sheath 10a of the interlocking cable 10 is fixed to the second support part 28c, and the other end of the cable 10b projecting from the sheath 10a is connected to the connecting member 33. The braking characteristic setting spring 91, i.e., a compression coil spring, is compressed between the second support part 28c of the lower holder 28, i.e., the fixed member fixed to the body, and the connecting member 33, i.e., a component member of the interlocking brake operating force transmitting system 41, so as to surround the end portion of the cable 10b to bias the auxiliary brake operating member 81 in a direction to separate the working portion 8a from the front brake lever 6lt i.e., to bias the cable 10b of the sheathed cable 10 in a direction opposite a direction in which the cable 10b is pulled to turn the front brake lever 6a for braking operation. [0 0 2 3] Referring to Figs. 4 and 5, a grip 34 to be grasped by the driver's left hand is attached to a left end portion of the handlebar 25. An upper holder 35 and a lower holder 36 are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 34 and are fastened together and fixed to the handlebar 25 with a pair of bolts 37. A box 36a having an open upper end is formed integrally with the lower holder 36, and a flat cover 35a for covering the open upper end of the box 36a is formed integrally with the upper holder 35. The cover 35a is fastened to the box 36a with the bolts 37 and bolts 38 to form a housing 39. [0 0 2 4] A bracket 36b is formed integrally with the lower holder 36. The rear brake lever 7i is supported at its base end for turning by a shaft 40 on the bracket 36b. The rear brake lever 7X can be operated by the left hand gripping the grip 34. [0 0 2 5] One end of a connecting rod 41 is connected to the base end of the rear brake lever 71, and the connecting rod 41 is inserted through a side wall of the housing 39 into the housing 39 so as to be axially movable. The equalizer 121 is placed in the housing 39, a connecting member 42 joined to the other end of the connecting rod 41 is connected by a connecting pin 43 to a substantially middle portion of the equalizer 121-[0 0 2 6] One end of the sheath 10a of the interlocking cable 10 is fixed to the housing 39, and one end of cable 10b projecting from the sheath 10a into the housing 39 is connected to one end of the equalizer 12a. The rear brake cable 11 has one end connected to the brake arm 23 of the rear brake BR. The sheath 11a of the rear brake cable 11 is fixed to the housing 39, and a portion of the cable l1b projecting from the sheath 11a is connected to the other end of the equalizer 121. [0 0 2 7] A brake operating force produced by operating the rear brake lever 71 is transmitted through the connecting rod 41 and the connecting member 42 to the equalizer 121. The equalizer 122 merely turns on the joint of the interlocking cable 10 and the equalizer 121 while the brake operating force is lower than the resilient force of the braking characteristic setting spring 91, and the brake operating force, i.e., a pulling force, is transmitted through the rear brake cable 11 to the rear brake BR1 and makes the rear brake BR1 produce a braking force. If the brake operating force produced by operating the rear brake lever 71 is equal to or higher than the resilient force of the braking characteristic setting spring 91, the equalizer 121 is able to compress the braking characteristic setting spring 91 to turn the auxiliary operating member 81. In this state, the equalizer 121 moves to the left, as viewed in Fig. 4, to pull both the interlocking cable 10 and the rear brake cable 11. [0 0 2 8] The connecting member 42 is provided integrally with a stopper 42a which engages with the equalizer 121. The stopper 42a restrains the equalizer 121 from turning on the connecting pin 43 in a direction to loosen the rear brake cable 11. [0 0 2 9] The operation of the first embodiment will be described hereinafter. Referring to Fig-; 6, if only the front brake lever 61 is operated and the rear brake lever 71 is not operated, the front brake cable 31 is pulled to apply the front brake BF1, and only a front wheel braking force indicated by a line segment A-B in Fig. 7 is produced. [0 0 3 0] If the rear brake lever 71 is operated for braking without operating the front brake lever 61, the equalizer 12x turns on the joint of the same and the interlocking cable 10 as shown in Fig. 8 if the brake operating force produced by operating the rear brake lever 7a is lower than the resilient force of the braking characteristic setting spring 91, whereby the rear brake cable 11 is pulled to apply the rear brake BR1. In this case, only a rear wheel braking force indicated by a line segment A-C in Fig. 7 is produced. [0 0 3 1] If the rear brake lever 71 is operated for braking without operating the front brake lever 61 so that a brake operating force higher than the resilient force of the braking characteristic setting spring 91 is produced, the equalizer 121 moves, pulling" both the interlocking cable 10 and the rear brake cable 11 as shown in Fig. 9. Consequently, the auxiliary operating member 8a is brought into engagement with the front brake lever 61 and turns the front brake lever 61 in a braking direction to make the front brake BF1 produce a braking force. In this state, the front-rear interlocked brake system exercises a braking characteristic indicated by a line segment C-D in Fig. 7. [0 0 3 2] Thus, the front-rear interlocked brake system exercises a braking characteristic indicated by a polygonal line A-C-D if the rear brake lever 71 is operated and the front brake lever 61 is not operated, so that the front-rear interlocked brake system distributes a front wheel braking force and a rear wheel braking force in distribution ratios nearly equal to ideal distribution ratios. A rear wheel braking force L at a point C in Fig. 7 exercised by the rear brake BR1 when only the rear brake lever 71 is operated by a relatively low brake operating force without operating the front brake lever 61 is dependent on the resilience of the braking characteristic setting spring 91. Therefore, different braking characteristic-setting springs 91 are used selectively for different types of motorcycles, respectively. Thus, the braking characteristic of the front-rear interlocked brake system can easily be adjusted by using the braking characteristic setting spring 91 of a desired property. [0 0 3 3] If both the front brake lever 61 and the rear brake lever 71 are operated simultaneously for braking operation, the equalizer 121 moves as shown in Fig. 10, and both the front brake BF1 and the rear brake BR1 produce braking forces. The movement of the equalizer 121 is dependent on the brake operating force applied to the rear brake lever 1\, and the distribution ratios of the front wheel braking force and the rear wheel braking force vary in a shaded region shown in Fig. 7 according to the ratio between the brake operating forces applied to the front brake lever 61 and the rear brake lever 71. [0 0 3 4] If the interlocking cable 10 is broken accidentally, the stopper 42a of the connecting member 42 connected to the rear brake lever 71 engages with the equalizer 121 to restrain the equalizer 121 from turning on the connecting pin 43 in the direction to loosen the rear brake cable 11. Therefore, the brake operating force applied to the rear brake lever 71 can surely be used for pulling the rear brake cable 11 to enable the rear brake BR1 to secure a braking force surely, which enhances the reliability of the front-rear interlocked brake system. [0 0 3 5] Thus, the interlocked braking operation of the front brake BF1 and the rear brake BR1 by the brake applying operation of the rear brake lever 71 can be achieved. If the front brake BF1 is a disk brake which requires a relatively low brake operating force to produce a relatively high braking force, the gradient 6 of the braking characteristic curve in the interlocked braking mode (Fig. 7) can easily be determined. If a mechanical drum brake is used as the rear brake BR1, the cost of the front-rear interlocked brake system can be reduced, and the front-rear interlocked brake system can be incorporated into a motor scooter of a relatively low price. However, if both the front brake Bri and the rear brake BRI are drum brakes, the front-rear interlocked brake system needs a troublesome cable adjusting work when the brake linings are abraded. [0 0 3 6] A front-rear interlocked brake system in a second embodiment according to the present invention is shown in Fig. 11, in which parts like or corresponding to those of the first embodiment are designated by the same reference characters. [0 0 3 7] A front brake BF2 is a disk brake not provided with any master cylinder. A liquid pressure produced by a front wheel master cylinder 45 which is operated directly by a front brake lever 62 is controlled by a modulator 46, and a modulated liquid pressure is applied to the front brake BF2. The modulator 46 is controlled by an electronic control unit 47 on the basis of a detection signal provided with a sensor 48, such as a rear wheel speed sensor. [0 0 3 8] An interlocking brake operating force transmitting system 42 comprises a interlocking cable 10 having one end connected to an equalizer 12lf and an auxiliary operating member 82 having one end connected to the other end of the interlocking cable 10. The auxiliary operating member 82 and a front brake lever 62 are supported for turning on a pivot shaft 49. The other end of the auxiliary operating member 82 is capable of engaging with the f front brake lever 62 from the brake releasing side of the front brake lever 62. The interlocking cable 10 is biased in a direction to disengage the auxiliary operating member 82 from the front brake lever 62 by a braking characteristic setting spring 91. If a brake operating force higher than the resilience of the braking characteristic setting spring 9i is applied to the equalizer 12x by the rear brake lever 7i, the auxiliary operating member 82 turns the front brake lever 62 in a brake applying direction for a front-rear interlocked brake operating mode. [0 0 3 9] The second embodiment exercises the same effects as those exercised by the first embodiment. [0 0 4 0] Figs. 12 to 15 show a front-rear interlocked brake system in a third embodiment according to the present invention, in which Fig. 12 is a sectional view of a left end portion of a handlebar, Fig. 13 is a sectional view taken on line 13-13 in Fig. 12, Fig. 14 is a sectional view taken on line 14-14 in Fig. 12, and Fig. 15 is a sectional view taken on line 15-15 in Fig. 12. [0 0 4 1] A grip 34 is attached to a left end portion of the handlebar 25. An upper holder 35' and a lower holder 36' are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 34 and are fastened together and fixed to the handlebar 25 with a pair of bolts 37. The lower holder 36' is provided integrally with a box 36a' having an open front end, and a cover 50 is fastened to the box 36a' with a pair of screws 51 so as to close the open front end of the box 36a'. The box 36a' and the cover 50 form a housing 39'. The cover 50 is provided integrally with a pair of bosses 50a and 50b. The free ends of the bosses 50a and 50b come into contact with the inner surface of the bottom wall of the box 36a' when the cover 50 is fastened to the open front end of the box 36a'. The pair of screws 51 are inserted into bores formed through the bosses 50a and 50b, and are screwed in the bottom wall of the box 36a'. [0 0 4 2] A bracket 36b' is formed integrally with the lower holder 36', and a rear brake lever 72 is supported for turning at its base end on the bracket 36b' by a shaft 40. One end of a connecting rod 41 is connected to the base end of the rear brake lever 72, and the connecting rod 41 is inserted through a side wall of the housing 39' into the housing 39' so as to be axially movable. An equalizer 122 is placed in the housing 39', a connecting member 42' joined to the other end of the connecting rod 41 is connected by a connecting pin 43 to a substantially middle portion of the equalizer 121. One end of the sheath 10a of an interlocking cable 10 is fixed to the housing 39', and one end of a cable 10b projecting from the sheath 10a into the housing 39' is connected to one end of the equalizer 121. The sheath 11a of a rear brake cable 11 is fixed to the housing 39', and a portion of a cable l1b projecting from the sheath 11a is connected to the other end of the equalizer 121. [0 0 4 3] An inhibitor housing 52 is fastened to the outer surface of the cover 50 of the housing 39' with the pair of screws 51 and 51 fastening the cover 50 to the box 36a'. An inhibitor 53 is contained in the inhibitor housing 52, and a slider 54 is slidably fitted in the inhibitor housing 52 so as to be able to come into contact with the inhibitor 53. An end portion of the slider 54 projects outside from the inhibitor housing 52, and a slot 55 is formed in the end portion of the slider 54. A pin 56 fixed to the rear brake lever 72 is inserted in the slot 55. The soot 55 is formed so that the slider 54 is moved away from the inhibitor 53 when the rear brake lever 72 is turned for brake applying operation through an angle beyond a predetermined angle. An extension spring 57 is extended between the inhibitor housing 52 and the slider 54 to bias the slider 54 toward the inhibitor 53. [0 0 4 4] The bosses 50a and 50b are formed integrally with the cover 50 so as to correspond to the opposite ends of the equalizer 121, respectively. The bosses 50a and 50b serve as stoppers to limit the movement of the equalizer 121 when a maximum brake operating force is applied to the rear brake lever 72. [0 0 4 5] The third embodiment exercises an effect in addition to effects similar to those exercised by the foregoing embodiments. In the third embodiment, the inhibitor 53 actuates the self-starting motor of the motorcycle upon the detection of the turning of the rear brake lever 72 through a predetermined angle. Even if the interconnecting cable 10 is broken accidentally, the reduction of the pulling force of the rear brake cable 11 can be avoided by increasing the brake operating force to an extent high enough to bring the equalizer 122 into contact with the bosses 50a and 50b to secure a rear wheel braking force. [0 0 4 6] A front-rear interlocked brake system in a fourth embodiment according to the present invention will be described with reference to Figs. 16 and 17. Fig. 16 is a partly sectional diagrammatic view of the front-rear interlocked brake system and Fig. 17 is an enlarged longitudinal sectional view of a rear brake pedal and an interlocking master cylinder. [0 0 4 7] The front-rear interlocked brake system has a front brake lever 62, i.e., a front brake operating member, for operating a hydraulic front brake BF3, a brake pedal 72, i.e., a rear brake operating member, capable of simultaneously applying both the front brake BF3 and a mechanical rear brake BR2 when a certain brake operating force is applied thereto. [0 0 4 8] The brake pedal 72 is connected by a connecting rod 61 to a substantially middle portion of an equalizer 122 having one end connected to an interlocking brake operating force transmission system 43 and the other end connected to a brake rod 62, i.e., a rear brake operating force transmitting member, connected to the rear brake BR2. [0 0 4 9] The front brake BF3 is a disk brake having a pair of first caliper pistons 631 and 632 operated by an output liquid pressure of a front master cylinder 45 operated by the front brake lever 62, and a second caliper piston 64 operated by a liquid pressure transmitted thereto by the interlocking brake operating force transmitting system 43. The front brake BF3 can be made to exercise a braking force by either the output liquid pressure of the front master cylinder 45 or the liquid pressure transmitted thereto by the interlocking brake operating force transmitting system 43. The rear brake BR2 comprises a brake drum 17 mounted on a rear axle 16, a brake panel 18, a pair of brake shoes 20 pivotally supported by a pin 19 on the brake panel 18 and capable of being brought into frictional contact with the inner circumference of the brake drum 17, a brake cam 22 supported for turning on the brake panel 18 to operate the pair of brake shoes 20 so that the pair of brake shoes 20 are pressed against the inner circumference of the brake drum 17, a brake arm 23 having a base end connected to the brake cam 22 and extending outside from the brake drum 17, a fixed arm 65 fixed to the brake drum 17 so as to extend opposite to the brake arm 23, and a return spring 66 compressed between the brake arm 23 and the fixed arm 65 and biasing the brake arm 23 in a direction to make the brake shoes 20 approach each other. The other end of the brake rod 62 having the one end connected to the equalizer 122 is connected to the brake arm 23. [0 0 5 0] The interlocking brake operating force transmitting system 43 comprises an interlocking master cylinder 68 to be operated by the equalizer 122, and a line 69 having one end connected to the interlocking master cylinder 68 and the other end connected to the front brake BF3 to transmit the output liquid pressure of the interlocking master cylinder 68 to the second caliper piston 64 of the front brake BF3. [0 0 5 1] The interlocking master cylinder 68 has a cylinder body 70 fixed to the body, and a master piston 72 fitted slidably in the bore of the cylinder body 70 with its front end facing a liquid pressure chamber 71 connected to a line 69. The rear end of a piston rod 73 extending rearward from the master piston 72 is joined to one end of the equalizer 122. A return spring 74 for biasing the master piston 72 rearward is placed in the liquid pressure chamber 71. A stop ring 75 is fitted in a groove formed in a rear end portion of the inner circumference of the cylinder body 70 to limit the rearward movement of the master piston 72. [0 0 5 2] A pair of cup seals 77 and 78 are mounted on the master cylinder to define a liquid supply chamber 76 by the outer circumference of the master piston 72, the inner circumference of the cylinder body 70 and the pair of cup seals 77 and 78. The cup seal 77 disposed between the liquid pressure chamber 71 and the liquid supply chamber 76 allows a brake fluid to flow from the liquid supply chamber 76 to the liquid pressure chamber 71. [0 0 5 3] A reservoir tank 80 is connected to the cylinder body 70 by a vertical pipe 79. The cylinder body 70 is provided with a release port 81 and a supply port 82, which are connected through the pipe 79 to the reservoir tank 80. The release port 81 opens into the liquid pressure chamber 71 when the master piston 72 is retracted to its rearmost position, and the supply port 82 is always open into the supply chamber 76. [0 0 5 4] A braking characteristic setting spring 92 is compressed between the stop ring 75, i.e., a fixed member, fixed to the cylinder body 70, and a flange 73a formed on the piston rod 73, i.e., a component member of the interlocking brake operating force transmitting system 43. [0 0 5 5] In a braking mode in which the brake pedal 72 is operated and the front brake lever 62 is not operated, the equalizer 122 turns on the joint of the equalizer 122 and the piston rod 73 to pull the brake rod 62 so that the rear brake BR2 is applied if the brake operating force of the brake pedal 72 is less than the resilient force of the braking characteristic setting spring 92 or the equalizer 122 is moved to push the piston rod 73 and to pull the brake rod 62 so that both the front brake BF2 and the rear brake BR2 are applied if the brake pedal 72 is operated by a brake operating force equal to or higher than the resilience of the braking characteristic setting spring 92. Thus, the front-back interlocking brake system can be constructed by adding a small number of parts including the equalizer 122 and the interlocking master cylinder 68 to a motorcycle provided with a brake pedal 72 as a rear brake operating member, and a mechanical rear brake BR2. [0 0 5 6] A front-rear interlocked brake system in a fifth embodiment according to the present invention will be described with reference to Figs. 18 and 19. Fig. 18 is a partly sectional diagrammatic view of the front-rear interlocked brake system and Fig. 19 is an enlarged longitudinal sectional view of a front master cylinder. [0 0 5 7] The front-rear interlocked brake system has a front brake lever 62 for applying a hydraulic front brake BF2, and a brake pedal 72 capable of simultaneously applying both the front brake BF2 and a mechanical rear brake BR2 when a certain brake operating force is applied thereto. The brake pedal 72 is connected by a connecting rod 61 to an equalizer 122 having one end connected to an interlocking brake operating force transmission system 44 and the other end connected to a brake rod 62 connected to the rear brake BR2- [0 0 5 8] The front brake Br2 is operated by an output liquid pressure of a front master cylinder 45' operated by the front brake lever 62. The front brake BF2 is connected by a line 87 to a liquid pressure chamber 86 of the master cylinder 45' in which a master piston 85 operates. [0 0 5 9] The interlocking brake operating force transmitting system 44 comprises a braking characteristic setting spring 92 compressed between a stop ring 75 and a flange 73a, an interlocking master cylinder 68 to be operated by an equalizer 122, and a line 83 connected to a liquid pressure chamber 71 formed in the interlocking master cylinder 68. The line 83 is connected to the interlocking master cylinder 68 so that a liquid pressure produced in the liquid chamber 86 of the front master cylinder 45' when the master piston 85 of the front master cylinder 45' operates may not be applied to the interlocking master cylinder 68. In the front master cylinder 45', an annular supply chamber 91 is defined by the inner circumference of the cylinder body 88, the outer circumference of the master piston 85 and a pair of cup seals 89 and 90. The cylinder body 88 is provided with a release port 92 and a supply port 93, which are connected through the pipe 79 to the reservoir tank 80. The release port 92 opens into the liquid pressure chamber 86 when the master piston 72 is retracted to its rearmost position, and the supply port 93 is always open into the supply chamber 91. The line 83 of the interlocking brake operating force transmitting system 44 is connected to the front master cylinder 45' so as to be connected to the release port 92 and the supply port 93. [0 0 6 0] In the fifth embodiment, both the front brake Br2 and the rear brake BR2 can simultaneously be applied by operating the brake pedal 72 by an operating force equal to or higher than a predetermined operating force determined by adjusting the braking characteristic setting spring 92 when the front brake lever 62 is not operated and the piston 85 of the front master cylinder 45' is at its rearmost position. The fifth embodiment is able to exercise the same effects as those exercised by the fourth embodiment, and enables the reduction of the number of parts because the interlocking master cylinder 86 and the front master cylinder 45' are able to share the reservoir tank 80 combined with the interlocking master cylinder 86. [0 0 6 1] Fig. 20 shows a front-rear interlocked brake system in a sixth embodiment according to the present invention, in which parts like or corresponding to those of the foregoing embodiments are designated by the same reference characters. [0 0 6 2] The front-rear interlocked brake system has a front brake lever 63 for applying a hydraulic front brake BF2, and a brake pedal 72 capable of simultaneously applying both the front brake Br3 and a mechanical rear brake BR2 when a certain brake operating force is applied thereto. The brake pedal 72 is connected by a connecting rod 61 to an equalizer 122 having one end connected to an interlocking brake operating force transmission system 45 and the other end connected to a brake rod 62 connected to the rear brake BR2' [0 0 6 3] The interlocking brake operating force transmitting system 45 has an interlocking cable 10 connected to one end of the equalizer 122, and a push lever 96 having a base end pivotally supported by a shaft 95 at a fixed position to apply a pressure to a piston included in a front master cylinder 45 connected to the front brake BF2. The interlocking cable 10 is connected to a free end of the push lever 96. A braking characteristic setting spring 93 is compressed between a lug 97 formed integrally with the front master cylinder 45, and the free end of the push lever 96, i.e., a component part of the interlocking brake operating force transmitting system 45. [0 0 6 4] The front brake lever 63 and the push lever 96 are supported for turning on a shaft 95. The push lever 96 is provided with a projection 96a with which the front brake lever 63 engages to apply a pressure to the piston of the front master cylinder 45 when operated for braking. [0 0 6 5] In the sixth embodiment, only the push lever 96 can be turned, leaving the front brake lever 63 at an inoperative position, to make the front master cylinder 45 apply a liquid pressure to the front brake Br2 by operating the brake pedal 72 by a brake operating force equal to or higher than a predetermined operating force determined by adjusting the braking characteristic setting spring 93. Thus, both the front brake BF2 and the rear brake BR2 can simultaneously be applied in a front-rear interlocked braking mode. The sixth embodiment exercises the same effects as those of the fourth and the fifth embodiment, and needs less component parts than the fourth and the fifth embodiment because the sixth embodiment does not need any master cylinder corresponding to the interlocking master cylinder 68. [0 0 6 6] Although the preferred embodiments of the present invention has been described, the present invention is not limited in its practical application to those embodiments specifically described herein, and many changes and variations are possible therein without departing from the scope and spirit thereof as set forth in the appended claims. [0 0 6 7] [Effect of the Invention] According to the inventions stated in claims 1 to 9, the front brake is applied to produce a braking force by operating the front brake operating member for a braking operation without operating the rear brake operating member. When the rear brake operating member is operated for a braking operation and the front brake operating member is not operated, only the rear brake is applied if the brake operating force applied to the rear brake operating member is less than a force corresponding to the resilience of the braking characteristic setting spring or both the rear and the front brake are applied in a front-rear interlocked braking mode if the brake operating force applied to the rear brake operating member is equal to or higher than the force corresponding to the resilience of the braking characteristic setting spring. Thus, only the rear brake produces a relatively low braking force in an initial stage of a brake operating operation, and the front-rear interlocked brake system has a simple construction. [0 0 6 8] According to the invention stated in claim 3, the equalizer is unable to turn on the joint of the equalizer and the connecting member in a direction to reduce the rear brake operating force transmitted by the rear brake operating force transmitting member. Therefore, the braking force of the rear brake can surely be secured when the rear brake operating member is operated even if the interlocking brake operating force transmitting system is broken accidentally. [0 0 6 9] According to the inventions stated in claims 5 to 9, in a vehicle in which the rear brake operating member is a brake pedal and the rear brake is of a mechanical type, the front-rear interlocked brake system can easily be constructed by adding the least necessary number of parts to the vehicle. Particularly, according to the invention stated in claim 9, the front-rear interlocked brake system does not need any interlocking master cylinder, which is necessary for the inventions stated in claims 6 to 8, the number of parts necessary for constructing the front-rear interlocked brake system can further be reduced. [REFERENCE CHARACTERS] 41, 42, 43, 44, 45 ... Interlocking brake operating force transmitting systems 61, 62, 63 ... Front brake levers (Front brake operating members) 7i ... Rear brake lever (Rear brake operating member) 72 ... Brake pedal (Rear brake operating member) 9i/ ^2/ ^3 ••• Braking characteristic setting springs 10 ... Interlocking cable 11 ... Rear brake cable (Rear brake operating force transmitting member 12l, 122 ... Equalizers 28 ... Lower holder (Fixing member) 33 ... Connecting member (Component of interlocking brake operating force transmitting system) 42 ... Connecting member 42a ... Stopper 45, 45' — Front master cylinders 62 ... Brake rod (Rear brake operating force transmitting member 63i, 632 — First caliper pistons 64 ... Second caliper piston 68 ... Interlocking master cylinder 73 — Piston rod (Component of an interlocking brake operating force transmitting system) 75 ... Stop ring (Fixing member) 85 ... Master piston 86 ... Liquid pressure chamber 96 ... Push lever (Component of interlocking brake operating force transmitting system) 97 ...Lug (Fixed member) BF1, BF2, BF3 ••• Front brakes BR1, BR2 ... Rear brakes WE CLAIMS [Claim 1] A front-rear interlocked brake system for a vehicle, comprising: a front brake operating member (6l, 62, 63) to apply a front brake (BF1, BF2, BF3) in response to a brake applying operation; and a rear brake operating member (71, 72) capable of applying both a rear brake (BRJ, B^) and the front brake (BF1, BF2, BR3); the improvement comprising: a component member (33, 73, 96) of an interlocking brake operating force transmitting system (41, 42, 43, 44, 45) capable of transmitting a brake operating force applied to the rear brake operating member (71,72) to the front brake (BF1, BF2, BF3); a fixed member (28, 75, 97) fixed to a body; and a braking characteristic setting spring (91, 92, 93) for applying a force acting in a direction opposite the direction in which the rear brake operating member ((7l, 72) applies a force to the interlocking brake operating force transmitting system (41, 42, 43, 44, 45), disposed between the component member (33, 73, 96) of the interlocking brake operating force transmitting system (4l, 42, 43, 44, 45), and the fixed member (28, 75, 97). [Claim 2] The front-rear interlocked brake system according to claim 1, wherein the rear brake operating member (71, 72) is connected to a substantially middle portion of an equalizer (12l, 122), one end of the interlocking brake operating force transmitting system (4l, 42, 43, 44, 45) and one end of a rear brake operating force transmitting member (11, 62) connected to the rear brake (BR1, BF2) are connected to opposite end portions of the equalizer (121, 122), respectively, and the equalizer (121, 122) is capable of turning on the joint of the equalizer (121, 122) and the interlocking brake operating force transmitting system (41, 42, 43, 44, 45) which exerts a brake operating force through the rear brake operating force transmitting member (11, 62) on the rear brake (BR1, BF2) when the brake operating force of the rear brake operating member (71, 72) is less than a force corresponding to the force of the braking characteristic setting spring (91, 92, 93), and of driving the front brake (BF1, BF2, BF3)through the interlocking brake operating force transmitting system (41, 42, 43, 44, 45) and driving the rear brake (BR1, BR1) through the rear brake operating force transmitting member (11, 62) when the brake operating force of the rear brake operating member ((7l, 72) is not lower than a force corresponding to the force of the braking characteristic setting spring ((91, 92, 93). [Claim 3] The front-rear interlocked brake system for a vehicle, according to claim 2, wherein the rear brake operating member (7i) is connected by a connecting member (42) to the equalizer (12i), and the connecting member (42) is provided with a stopper (42a) that engages with the equalizer (12i) in a direction to stop the turning of the equalizer (12i) on a joint of the equalizer (12i) and the connecting member (42) in a direction to reduce the force transmitted through the rear brake operating force transmitting member (11). [Claim 4] The front-rear interlocked brake system for a vehicle, according to claim 3, wherein the interlocking brake operating force transmitting system (41) has an interlocking cable (10) having one end connected to the equalizer (121) and the other end connected to the front brake operating member (61), and capable of transmitting a brake operating force the rear brake operating member (71) to the front brake operating member (61). [Claim 5] The front-rear interlocked brake system for a vehicle, according to claim 2, wherein the rear brake operating member (72) is a brake pedal, the rear brake operating member (72) is connected to a substantially middle portion of the equalizer (122), the interlocking brake operating force transmitting system (43, 44, 45) is connected to one end of the equalizer (122)/ and the mechanical rear brake (BR2) is connected through the rear brake operating force transmitting member (62) to the other end of the equalizer (122). [Claim 6] The front-rear interlocked brake system for a vehicle, according to claim 2, the interlocking brake operating force transmitting system (43, 44) is provided with an interlocking master cylinder (68) interlocked with the equalizer (122) and capable of producing a liquid pressure to be applied to the hydraulic front brake (BF2, BF3). [Claim 7] The front-rear interlocked brake system for a vehicle, according to claim 6, wherein the hydraulic front brake (BF3) is a disk brake comprising a first caliper piston (631, 632) operated by a liquid pressure produced by a front master cylinder (45) according to the operation of the front brake operating member (62), and a second caliper piston (64) operated by a liquid pressure produced by the interlocking master cylinder (68). [Claim 8] The front-rear interlocked brake system for a vehicle, according to claim 6, wherein the interlocking master cylinder (68) is connected to a hydraulic system interconnecting a liquid pressure chamber (86) in which the master piston (85) of a front master cylinder (45') operated by the front brake operating member (62) is placed and the front brake (BF2) so as to inhibit the exertion of a liquid pressure produced in the liquid pressure chamber (86) by the master piston (85) on the interlocking master cylinder (68). [Claim 9] The front-rear interlocked brake system for a vehicle, according to claim 5, wherein the interlocking brake operating force transmitting system (45) comprises an interlocking cable (10) having one end connected to the equalizer (122), and a front master cylinder (45) which produces a liquid pressure to be applied to the hydraulic front brake (BF2) when operated by pulling the interlocking cable (10) or the operation of the front brake operating member (63). 10. A. front-rear interlocked brake system for a vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Full Text

[DETAILED DESCRIPTION OF THE INVENTION] [0 0 0 1]
[Technical Field of the Invention]
The present invention relates to a front-rear interlocked brake system for a vehicle, comprising a front brake operating member to be operated to operate a front brake, and a rear brake operating member capable of operating both the front brake and a rear brake when operated and, more particularly, to a front-rear interlocked brake system suitable for use on a motorcycle. [0 0 0 2]
[Related Art]
Interlocked front-rear brake systems have been disclosed in, for example, JP-B No. 47-3298 and JP-A No. 50-53842.
[0 0 0 3]
[Problem to be Solved by the Invention] In the foregoing known interlocked front-rear brake systems, a reaction force of a rear brake operated by a brake applying operation of a rear brake operating member is transmitted to a front brake to apply both the front brake and the rear brake. However, the known interlocked front-rear brake systems have a complicated construction. Fig. 21 shows a previously proposed interlocked front-rear brake system of a simple construction. Referring to Fig, 21, a liquid pressure produced by a front brake master cylinder MF operated by a front brake operating member 6' is applied to a front disk brake BF', a liquid pressure produced by a rear brake master cylinder MR operated by a rear brake operating member 7' is applied through a proportional control valve V to a rear disk brake BR ', and an interlocking cable 10' is connected to the rear brake operating member 7' and the front brake operating member 6' so that only the brake operating force of the rear brake operating member 7' can be transmitted to the front brake operating member 6'. In this known interlocked front-rear brake system, the front brake operating member 6' operates
upon the brake applying operation of the rear brake operating member 7', so that the front and the rear brake are applied immediately after the operation of the rear brake operating member 7'. [0 0 0 4]
The present invention has been made in view of the foregoing circumstances and it is therefore an object of the present invention to provide a front-rear interlocked brake system for a vehicle, having a simple construction for the interlocked operation of a front brake and a rear-brake, and capable of making only the rear brake operate in an initial stage of application of a brake operating force and making both the rear brake and the front brake operate after the increase of the brake operating force beyond a predetermined value. [0 0 0 5]
[Means for Solving the Problem]
With the foregoing object in view, according to an invention stated in claim 1, a front-rear interlocked brake system for a vehicle, comprises: a front brake operating member to apply a front brake in response to a brake applying operation; and a rear brake operating member
capable of applying both a rear brake and the front brake. The interlocked front-rear brake system is provided with a component member of an interlocking brake operating force transmitting system capable of transmitting a brake operating force applied to the rear brake operating member to the front brake; a fixed member fixed to a body, and a braking characteristic setting spring for applying a force acting in a direction opposite the direction in which the rear brake operating member applies a force to the interlocking brake operating force transmitting system, disposed between the component member of the interlocking brake operating force transmitting system, and the fixed member. [0 0 0 6]
According to the invention stated in claim 2, in the interlocked front-rear brake system stated in claim 1, the rear brake operating member is connected to a substantially middle portion of an equalizer, one end of the interlocking brake operating force transmitting system and one end of a rear brake operating force transmitting member connected to the rear brake are connected to opposite end portions of the equalizer, respectively, and
the equalizer is capable of turning on the joint of the equalizer and the interlocking brake operating force transmitting system which exerts a brake operating force through the rear wheel braking force transmitting member on the rear brake when the brake operating force of the rear brake operating member is less than a force corresponding to the force of the braking characteristic setting spring, and of driving the front brake through the interlocking brake operating force transmitting system and driving the rear brake through the rear wheel braking force transmitting member when the brake operating force of the rear brake operating member is not lower than a force corresponding to the force of the braking characteristic setting spring. [0 0 0 7]
According to an invention stated in claim 3, in the front-rear interlocked brake system for a vehicle, according to claim 2, the rear brake operating member is connected by a connecting member to the equalizer, and the connecting member is provided with a stopper that engages with the equalizer in a direction to stop the turning of the equalizer on a joint of the equalizer and the
connecting member in a direction to reduce the force transmitted through the rear brake operating force transmitting member. [0 0 0 8]
According to an invention stated in claim 4, in the front-rear interlocked brake system for a vehicle, according to claim 3, the interlocking brake operating force transmitting system has an interlocking cable having one end connected to the equalizer and the other end connected to the front brake operating member, and capable of transmitting a brake operating force from the rear brake operating member to the front brake operating member. [0 0 0 9]
According to an invention stated in claim 5, in the front-rear interlocked brake system for a vehicle, according to claim 2, the rear brake operating member is a brake pedal, the rear brake operating member is connected to a substantially middle portion of the equalizer, the interlocking brake operating force transmitting system is connected to one end of the equalizer, and the mechanical rear brake is connected through the rear wheel braking force transmitting member to the other end of the
equalizer. [0 0 10]
According to an invention stated in claim 6, in the front-rear interlocked brake system for a vehicle, according to claim 2, the interlocking brake operating force transmitting system is provided with an interlocking master cylinder interlocked with the equalizer and capable of producing a liquid pressure to be applied to the hydraulic front brake. [0 0 11]
According to an invention stated in claim 7, in the front-rear interlocked brake system for a vehicle, according to claim 6, the hydraulic front brake is a disk brake comprising a first caliper piston operated by a liquid pressure produced by a front master cylinder according to the operation of the front brake operating member, and a second caliper piston operated by a liquid pressure produced by the interlocking master cylinder. [0 0 12]
According to an invention stated in claim 8, in the front-rear interlocked brake system for a vehicle, according to claim 6, the interlocking master cylinder is
connected to a hydraulic system interconnecting a liquid pressure chamber in which the master piston of a front master cylinder operated by the front brake operating member is placed and the front brake so as to inhibit the exertion of a liquid pressure produced in the liquid pressure chamber by the master piston on the interlocking master cylinder. [0 0 13]
According to an invention stated in claim 9, in the front-rear interlocked brake system for a vehicle, according to claim 5, the interlocking brake operating force transmitting system comprises an interlocking cable having one end connected to the equalizer, and a front master cylinder which produces a liquid pressure to be applied to the hydraulic front brake when operated by pulling the interlocking cable or the operation of the front brake operating member.
[BRIEF DESCRIPTION OF THE DRAWINGS]
[Fig. 1] Fig. 1 is a view showing the general arrangement of a front-rear interlocked brake system in a first embodiment according to the present invention.
[Fig. 2] Fig. 2 is a partly sectional plan view of a right end portion of a handlebar included in a motorcycle.
[Fig. 3] Fig. 3 is an enlarged sectional view taken on line 3-3 in Fig. 2.
[Fig. 4] Fig. 4 is a partly cut away plan view of a left end portion of the handlebar of the motorcycle.
[Fig. 5] Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 4.
[Fig. 6] Fig. 6 is view of the right and the left end portion of the handlebar in a state where only a front brake operating member is operated.
[Fig. 7] Fig. 7 is a graph showing the characteristics of front and rear wheel braking forces.
[Fig. 8] Fig. 8 is a view of the right and the
left end portion of the handlebar in a state where only a rear brake operating member is operated to apply the rear brake.
[Fig. 9] Fig. 9 is a view of the right and the left end portion of the handlebar in a state where only the rear brake operating member is operated to apply both the front and the rear brake for the front-rear interlocked braking operation.
[Fig. 10] Fig. 10 is a view of the right and the left end portion of the handlebar in a state where both the front and the rear brake operating member are operated.
[Fig. 11] Fig. 11 is a view showing the general arrangement of a front-rear interlocked brake system in a second embodiment according to the present invention.
[Fig. 12] Fig. 12 is a partly sectional view of a left end portion of a handlebar included in a front-rear interlocked brake system in a third embodiment according to the present invention.
[Fig. 13] Fig. 13 is a sectional view taken on line 13-13 in Fig. 12.
[Fig. 14] Fig. 14 is a sectional view taken on line 14-14 in Fig. 12.
[Fig. 15] Fig. 15 is a sectional view taken on line 15-15 in Fig. 12.
[Fig. 16] Fig. 16 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a fourth embodiment according to the present invention.
[Fig. 17] Fig. 17 is an enlarged longitudinal sectional view of a rear brake operating member and an interlocking master cylinder.
[Fig. 18] Fig. 18 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a fifth embodiment according to the present invention.
[Fig. 19] Fig. 19 is an enlarged longitudinal sectional view of a front master cylinder.
[Fig. 20] Fig. 20 is a partly sectional view showing the general arrangement of a front-rear interlocked brake system in a sixth embodiment according to the present invention.
[Fig. 21] Fig. 21 is a view showing the general arrangement of a prior art front-rear interlocked brake system.
[0 0 14]
[Description of the Preferred Embodiments] Preferred embodiments of the present invention will
be described hereinafter with reference to the accompanying
drawings.
[0 0 15]
Figs. 1 to 10 show a front-rear interlocked brake system in a first embodiment according to the present invention as applied to a motor scooter, in which Fig. 1 is a view showing the general arrangement of the front-rear interlocked brake system, Fig. 2 is a partly sectional plan view of a right end portion of a handlebar included in the motor scooter, Fig. 3 is an enlarged sectional view taken on line 3-3 in Fig. 2, Fig. 4 is a partly cut away plan view of a left end portion of the handlebar of the motor, scooter, Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 4, Fig. 6 is view of the right and the left end portion of the handlebar in a state where only a front brake operating member is operated, Fig. 7 is a graph showing the characteristics of front and rear wheel braking forces, Fig. 8 is a view of the right and the left end portion of the handlebar in a state where only a rear brake operating member is operated to apply the rear brake, Fig. 9 is a view of the right and the left end portion of the handlebar in a state where only the rear brake operating member is operated to apply both the front and the rear brake for the front-rear interlocked braking operation, and
Fig. 10 is a view of the right and the left end portion of the handlebar in a state where both the front and the rear brake operating member are operated. [0 0 16]
Referring to Fig. 1, the front-rear interlocked brake system has hydraulic front brake BF1, a front brake lever 61r i.e., a front brake operating member, for applying the hydraulic front brake BF1, a mechanical rear brake BR1, and a rear brake lever 7, by which both the front brake BF1 and the rear brake BR1 can simultaneously be applied. [0 0 17]
The rear brake lever 71 is connected to a substantially middle portion of an equalizer 121, and one end of an interlocking brake operating force transmitting system 41 and one end of a rear brake cable 11, i.e., a rear wheel braking force transmitting member, connected to the rear brake BR1 are connected to opposite end portions of the equalizer 12l, respectively. [0 0 18]
The interlocking brake operating force transmitting system 4i includes an interlocking cable 10 having one end
connected to the equalizer 121, and an auxiliary brake operating member 81 connected to the other end of the interlocking cable 10 and capable of engaging with the front brake lever 6a from the brake releasing side of the front brake lever 6j. The interlocking cable 10 is biased by a braking characteristic setting spring 9a in a direction to disengage the auxiliary brake operating member 8a from the front brake lever 61. [0 0 19]
The front brake Bri is a disk brake having a brake caliper 13, and a master cylinder 14 formed integrally with the brake caliper 13. A brake operating force is applied to a brake arm 15 associated with the master cylinder 14 and the master cylinder 14 produces a liquid pressure according to the brake operating force to produce a braking force. The rear brake BR1 is a drum brake comprising a brake drum 17 mounted on a rear axle 16, a brake panel 18, a pair of brake shoes 20 pivotally supported by a pin 19 on the brake panel 18 and capable of being brought into frictional contact with the inner circumference of the brake drum 17, a pair of springs 21 biasing the pair of brake shoes 20 toward each other, a brake cam 22 supported
for turning on the brake panel 18 to operate the pair of brake shoes 20 so that the pair of brake shoes 20 are pressed against the inner circumference of the brake drum 17, and a brake arm 23 having a base end connected to the brake cam 22 and extending outside from the brake drum 17. The rear brake BRI produces a braking force according to a brake operating force applied to the brake arm 23. [0 0 2 0]
Referring to Figs. 2 and 3, a grip 26 to be grasped by the driver's right hand is attached to a right end portion of a handlebar 25 provided in a front portion of the body of the motor scooter. An upper holder 27 and a lower holder 28 are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 26 and are fastened together and fixed to the handlebar 25 with a pair of bolts 29. The front brake lever 61 is supported for turning at its base end by a shaft 30 on a substantially U-shaped bracket 28a formed integrally with the lower holder 28. The front brake lever 61 is operated for a braking operation by the right hand gripping the grip 26. [0 0 2 1]
A first support part 28b is formed integrally with the lower holder 28 opposite to the base end of the front brake lever 61. One end of the sheath 31a of a front brake cable 31 is fixed to the first support part 28b. A cable 31b sheathed in the sheath 31a has one end connected to the base end of the front brake lever 61 The other end of the front brake cable 31 is connected to the brake arm 15 of the front brake BF1 as shown in Fig.l. When the front brake lever 61 is operated for braking, the front brake BF1 is applied. [0 0 2 2]
A lower end portion of the shaft 30 project downward from the bracket 28a, and the auxiliary brake operating member 81 is supported for turning on the lower end portion of the shaft 30. The auxiliary brake operating member 81 is provided integrally in one end portion thereof with a working portion 8a which engages with the front brake lever 61 from the side of the first support part 28b of the lower holder 28, i.e., the brake releasing side of the front brake lever 61. A connecting member 33 is connected to the other end portion of the auxiliary brake operating member 81 with a connecting pin 32 fitted in a
through hole formed in the other end portion of the auxiliary brake operating member 81 with its axis in parallel to that of the shaft 30. A second support part 28c is formed integrally with the lower holder 28 at a position spaced from the connecting member 33. The other end of the sheath 10a of the interlocking cable 10 is fixed to the second support part 28c, and the other end of the cable 10b projecting from the sheath 10a is connected to the connecting member 33. The braking characteristic setting spring 91, i.e., a compression coil spring, is compressed between the second support part 28c of the lower holder 28, i.e., the fixed member fixed to the body, and the connecting member 33, i.e., a component member of the interlocking brake operating force transmitting system 41, so as to surround the end portion of the cable 10b to bias the auxiliary brake operating member 81 in a direction to separate the working portion 8a from the front brake lever 6lt i.e., to bias the cable 10b of the sheathed cable 10 in a direction opposite a direction in which the cable 10b is pulled to turn the front brake lever 6a for braking
operation. [0 0 2 3]
Referring to Figs. 4 and 5, a grip 34 to be grasped by the driver's left hand is attached to a left end portion of the handlebar 25. An upper holder 35 and a lower holder 36 are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 34 and are fastened together and fixed to the handlebar 25 with a pair of bolts 37. A box 36a having an open upper end is formed integrally with the lower holder 36, and a flat cover 35a for covering the open upper end of the box 36a is formed integrally with the upper holder 35. The cover 35a is fastened to the box 36a with the bolts 37 and bolts 38 to form a housing 39. [0 0 2 4]
A bracket 36b is formed integrally with the lower holder 36. The rear brake lever 7i is supported at its base end for turning by a shaft 40 on the bracket 36b. The rear brake lever 7X can be operated by the left hand gripping the grip 34. [0 0 2 5]
One end of a connecting rod 41 is connected to the base end of the rear brake lever 71, and the connecting rod 41 is inserted through a side wall of the housing 39 into
the housing 39 so as to be axially movable. The equalizer 121 is placed in the housing 39, a connecting member 42
joined to the other end of the connecting rod 41 is connected by a connecting pin 43 to a substantially middle portion of the equalizer 121-[0 0 2 6]
One end of the sheath 10a of the interlocking cable 10 is fixed to the housing 39, and one end of cable 10b projecting from the sheath 10a into the housing 39 is connected to one end of the equalizer 12a. The rear brake cable 11 has one end connected to the brake arm 23 of the rear brake BR. The sheath 11a of the rear brake cable 11
is fixed to the housing 39, and a portion of the cable l1b projecting from the sheath 11a is connected to the other end of the equalizer 121. [0 0 2 7]
A brake operating force produced by operating the rear brake lever 71 is transmitted through the connecting rod 41 and the connecting member 42 to the equalizer 121. The equalizer 122 merely turns on the joint of the interlocking cable 10 and the equalizer 121 while the brake operating force is lower than the resilient force of the
braking characteristic setting spring 91, and the brake operating force, i.e., a pulling force, is transmitted through the rear brake cable 11 to the rear brake BR1 and makes the rear brake BR1 produce a braking force. If the brake operating force produced by operating the rear brake lever 71 is equal to or higher than the resilient force of the braking characteristic setting spring 91, the equalizer 121 is able to compress the braking characteristic setting spring 91 to turn the auxiliary operating member 81. In this state, the equalizer 121 moves to the left, as viewed
in Fig. 4, to pull both the interlocking cable 10 and the rear brake cable 11. [0 0 2 8]
The connecting member 42 is provided integrally with a stopper 42a which engages with the equalizer 121. The stopper 42a restrains the equalizer 121 from turning on the connecting pin 43 in a direction to loosen the rear brake cable 11. [0 0 2 9]
The operation of the first embodiment will be described hereinafter. Referring to Fig-; 6, if only the front brake lever 61 is operated and the rear brake lever
71 is not operated, the front brake cable 31 is pulled to apply the front brake BF1, and only a front wheel braking
force indicated by a line segment A-B in Fig. 7 is
produced.
[0 0 3 0]
If the rear brake lever 71 is operated for braking without operating the front brake lever 61, the equalizer 12x turns on the joint of the same and the interlocking cable 10 as shown in Fig. 8 if the brake operating force produced by operating the rear brake lever 7a is lower than the resilient force of the braking characteristic setting spring 91, whereby the rear brake cable 11 is pulled to apply the rear brake BR1. In this case, only a rear wheel braking force indicated by a line segment A-C in Fig. 7 is produced. [0 0 3 1]
If the rear brake lever 71 is operated for braking without operating the front brake lever 61 so that a brake operating force higher than the resilient force of the braking characteristic setting spring 91 is produced, the equalizer 121 moves, pulling" both the interlocking cable 10 and the rear brake cable 11 as shown in Fig. 9.
Consequently, the auxiliary operating member 8a is brought into engagement with the front brake lever 61 and turns the front brake lever 61 in a braking direction to make the front brake BF1 produce a braking force. In this state, the front-rear interlocked brake system exercises a braking characteristic indicated by a line segment C-D in Fig. 7. [0 0 3 2]
Thus, the front-rear interlocked brake system exercises a braking characteristic indicated by a polygonal line A-C-D if the rear brake lever 71 is operated and the
front brake lever 61 is not operated, so that the front-rear interlocked brake system distributes a front wheel braking force and a rear wheel braking force in distribution ratios nearly equal to ideal distribution ratios. A rear wheel braking force L at a point C in Fig. 7 exercised by the rear brake BR1 when only the rear brake
lever 71 is operated by a relatively low brake operating
force without operating the front brake lever 61 is
dependent on the resilience of the braking characteristic setting spring 91. Therefore, different braking
characteristic-setting springs 91 are used selectively for
different types of motorcycles, respectively. Thus, the
braking characteristic of the front-rear interlocked brake system can easily be adjusted by using the braking characteristic setting spring 91 of a desired property. [0 0 3 3]
If both the front brake lever 61 and the rear brake lever 71 are operated simultaneously for braking operation, the equalizer 121 moves as shown in Fig. 10, and both the front brake BF1 and the rear brake BR1 produce braking forces. The movement of the equalizer 121 is dependent on the brake operating force applied to the rear brake lever 1\, and the distribution ratios of the front wheel braking
force and the rear wheel braking force vary in a shaded region shown in Fig. 7 according to the ratio between the brake operating forces applied to the front brake lever 61 and the rear brake lever 71. [0 0 3 4]
If the interlocking cable 10 is broken accidentally, the stopper 42a of the connecting member 42 connected to the rear brake lever 71 engages with the equalizer 121 to restrain the equalizer 121 from turning on the connecting pin 43 in the direction to loosen the rear brake cable 11. Therefore, the brake operating force
applied to the rear brake lever 71 can surely be used for pulling the rear brake cable 11 to enable the rear brake BR1 to secure a braking force surely, which enhances the reliability of the front-rear interlocked brake system. [0 0 3 5]
Thus, the interlocked braking operation of the
front brake BF1 and the rear brake BR1 by the brake applying
operation of the rear brake lever 71 can be achieved. If
the front brake BF1 is a disk brake which requires a
relatively low brake operating force to produce a
relatively high braking force, the gradient 6 of the
braking characteristic curve in the interlocked braking
mode (Fig. 7) can easily be determined. If a mechanical
drum brake is used as the rear brake BR1, the cost of the
front-rear interlocked brake system can be reduced, and the
front-rear interlocked brake system can be incorporated
into a motor scooter of a relatively low price. However,
if both the front brake Bri and the rear brake BRI are drum
brakes, the front-rear interlocked brake system needs a
troublesome cable adjusting work when the brake linings are
abraded.
[0 0 3 6]
A front-rear interlocked brake system in a second embodiment according to the present invention is shown in Fig. 11, in which parts like or corresponding to those of the first embodiment are designated by the same reference characters. [0 0 3 7]
A front brake BF2 is a disk brake not provided with
any master cylinder. A liquid pressure produced by a front wheel master cylinder 45 which is operated directly by a front brake lever 62 is controlled by a modulator 46, and a modulated liquid pressure is applied to the front brake BF2. The modulator 46 is controlled by an electronic
control unit 47 on the basis of a detection signal provided with a sensor 48, such as a rear wheel speed sensor. [0 0 3 8]
An interlocking brake operating force transmitting system 42 comprises a interlocking cable 10 having one end connected to an equalizer 12lf and an auxiliary operating member 82 having one end connected to the other end of the interlocking cable 10. The auxiliary operating member 82 and a front brake lever 62 are supported for turning on a pivot shaft 49. The other end of the auxiliary operating
member 82 is capable of engaging with the f front brake lever 62 from the brake releasing side of the front brake lever 62. The interlocking cable 10 is biased in a direction to disengage the auxiliary operating member 82 from the front brake lever 62 by a braking characteristic setting spring 91. If a brake operating force higher than the resilience of the braking characteristic setting spring 9i is applied to the equalizer 12x by the rear brake lever 7i, the auxiliary operating member 82 turns the front brake lever 62 in a brake applying direction for a front-rear interlocked brake operating mode. [0 0 3 9]
The second embodiment exercises the same effects as those exercised by the first embodiment. [0 0 4 0]
Figs. 12 to 15 show a front-rear interlocked brake system in a third embodiment according to the present invention, in which Fig. 12 is a sectional view of a left end portion of a handlebar, Fig. 13 is a sectional view taken on line 13-13 in Fig. 12, Fig. 14 is a sectional view taken on line 14-14 in Fig. 12, and Fig. 15 is a sectional view taken on line 15-15 in Fig. 12.
[0 0 4 1]
A grip 34 is attached to a left end portion of the handlebar 25. An upper holder 35' and a lower holder 36' are put to the upper and the lower surface, respectively, of a portion of the handlebar 25 on the inner side of the grip 34 and are fastened together and fixed to the handlebar 25 with a pair of bolts 37. The lower holder 36' is provided integrally with a box 36a' having an open front end, and a cover 50 is fastened to the box 36a' with a pair of screws 51 so as to close the open front end of the box 36a'. The box 36a' and the cover 50 form a housing 39'. The cover 50 is provided integrally with a pair of bosses 50a and 50b. The free ends of the bosses 50a and 50b come into contact with the inner surface of the bottom wall of the box 36a' when the cover 50 is fastened to the open front end of the box 36a'. The pair of screws 51 are inserted into bores formed through the bosses 50a and 50b, and are screwed in the bottom wall of the box 36a'. [0 0 4 2]
A bracket 36b' is formed integrally with the lower holder 36', and a rear brake lever 72 is supported for turning at its base end on the bracket 36b' by a shaft 40.
One end of a connecting rod 41 is connected to the base end of the rear brake lever 72, and the connecting rod 41 is inserted through a side wall of the housing 39' into the housing 39' so as to be axially movable. An equalizer 122 is placed in the housing 39', a connecting member 42' joined to the other end of the connecting rod 41 is connected by a connecting pin 43 to a substantially middle portion of the equalizer 121. One end of the sheath 10a of an interlocking cable 10 is fixed to the housing 39', and one end of a cable 10b projecting from the sheath 10a into the housing 39' is connected to one end of the equalizer 121. The sheath 11a of a rear brake cable 11 is fixed to the housing 39', and a portion of a cable l1b projecting from the sheath 11a is connected to the other end of the equalizer 121. [0 0 4 3]
An inhibitor housing 52 is fastened to the outer surface of the cover 50 of the housing 39' with the pair of screws 51 and 51 fastening the cover 50 to the box 36a'. An inhibitor 53 is contained in the inhibitor housing 52, and a slider 54 is slidably fitted in the inhibitor housing 52 so as to be able to come into contact with the inhibitor
53. An end portion of the slider 54 projects outside from the inhibitor housing 52, and a slot 55 is formed in the end portion of the slider 54. A pin 56 fixed to the rear brake lever 72 is inserted in the slot 55. The soot 55 is formed so that the slider 54 is moved away from the inhibitor 53 when the rear brake lever 72 is turned for brake applying operation through an angle beyond a predetermined angle. An extension spring 57 is extended between the inhibitor housing 52 and the slider 54 to bias the slider 54 toward the inhibitor 53. [0 0 4 4]
The bosses 50a and 50b are formed integrally with the cover 50 so as to correspond to the opposite ends of the equalizer 121, respectively. The bosses 50a and 50b serve as stoppers to limit the movement of the equalizer 121 when a maximum brake operating force is applied to the
rear brake lever 72. [0 0 4 5]
The third embodiment exercises an effect in addition to effects similar to those exercised by the foregoing embodiments. In the third embodiment, the inhibitor 53 actuates the self-starting motor of the
motorcycle upon the detection of the turning of the rear brake lever 72 through a predetermined angle. Even if the interconnecting cable 10 is broken accidentally, the reduction of the pulling force of the rear brake cable 11 can be avoided by increasing the brake operating force to an extent high enough to bring the equalizer 122 into contact with the bosses 50a and 50b to secure a rear wheel braking force. [0 0 4 6]
A front-rear interlocked brake system in a fourth embodiment according to the present invention will be described with reference to Figs. 16 and 17. Fig. 16 is a partly sectional diagrammatic view of the front-rear interlocked brake system and Fig. 17 is an enlarged longitudinal sectional view of a rear brake pedal and an interlocking master cylinder. [0 0 4 7]
The front-rear interlocked brake system has a front brake lever 62, i.e., a front brake operating member, for operating a hydraulic front brake BF3, a brake pedal 72, i.e., a rear brake operating member, capable of simultaneously applying both the front brake BF3 and a
mechanical rear brake BR2 when a certain brake operating force is applied thereto. [0 0 4 8]
The brake pedal 72 is connected by a connecting rod 61 to a substantially middle portion of an equalizer 122 having one end connected to an interlocking brake operating force transmission system 43 and the other end connected to a brake rod 62, i.e., a rear brake operating force transmitting member, connected to the rear brake BR2. [0 0 4 9]
The front brake BF3 is a disk brake having a pair of first caliper pistons 631 and 632 operated by an output liquid pressure of a front master cylinder 45 operated by the front brake lever 62, and a second caliper piston 64
operated by a liquid pressure transmitted thereto by the interlocking brake operating force transmitting system 43. The front brake BF3 can be made to exercise a braking force
by either the output liquid pressure of the front master cylinder 45 or the liquid pressure transmitted thereto by the interlocking brake operating force transmitting system 43. The rear brake BR2 comprises a brake drum 17 mounted on a rear axle 16, a brake panel 18, a pair of brake shoes 20
pivotally supported by a pin 19 on the brake panel 18 and capable of being brought into frictional contact with the inner circumference of the brake drum 17, a brake cam 22 supported for turning on the brake panel 18 to operate the pair of brake shoes 20 so that the pair of brake shoes 20 are pressed against the inner circumference of the brake drum 17, a brake arm 23 having a base end connected to the brake cam 22 and extending outside from the brake drum 17, a fixed arm 65 fixed to the brake drum 17 so as to extend opposite to the brake arm 23, and a return spring 66 compressed between the brake arm 23 and the fixed arm 65 and biasing the brake arm 23 in a direction to make the brake shoes 20 approach each other. The other end of the brake rod 62 having the one end connected to the equalizer 122 is connected to the brake arm 23. [0 0 5 0]
The interlocking brake operating force transmitting system 43 comprises an interlocking master cylinder 68 to be operated by the equalizer 122, and a line 69 having one end connected to the interlocking master cylinder 68 and the other end connected to the front brake BF3 to transmit the output liquid pressure of the interlocking master
cylinder 68 to the second caliper piston 64 of the front brake BF3. [0 0 5 1]
The interlocking master cylinder 68 has a cylinder body 70 fixed to the body, and a master piston 72 fitted slidably in the bore of the cylinder body 70 with its front end facing a liquid pressure chamber 71 connected to a line 69. The rear end of a piston rod 73 extending rearward from the master piston 72 is joined to one end of the equalizer 122. A return spring 74 for biasing the master piston 72 rearward is placed in the liquid pressure chamber 71. A stop ring 75 is fitted in a groove formed in a rear end portion of the inner circumference of the cylinder body 70 to limit the rearward movement of the master piston 72. [0 0 5 2]
A pair of cup seals 77 and 78 are mounted on the master cylinder to define a liquid supply chamber 76 by the outer circumference of the master piston 72, the inner circumference of the cylinder body 70 and the pair of cup seals 77 and 78. The cup seal 77 disposed between the liquid pressure chamber 71 and the liquid supply chamber 76 allows a brake fluid to flow from the liquid supply chamber
76 to the liquid pressure chamber 71. [0 0 5 3]
A reservoir tank 80 is connected to the cylinder body 70 by a vertical pipe 79. The cylinder body 70 is provided with a release port 81 and a supply port 82, which are connected through the pipe 79 to the reservoir tank 80. The release port 81 opens into the liquid pressure chamber 71 when the master piston 72 is retracted to its rearmost position, and the supply port 82 is always open into the supply chamber 76. [0 0 5 4]
A braking characteristic setting spring 92 is compressed between the stop ring 75, i.e., a fixed member, fixed to the cylinder body 70, and a flange 73a formed on the piston rod 73, i.e., a component member of the interlocking brake operating force transmitting system 43. [0 0 5 5]
In a braking mode in which the brake pedal 72 is operated and the front brake lever 62 is not operated, the equalizer 122 turns on the joint of the equalizer 122 and the piston rod 73 to pull the brake rod 62 so that the rear brake BR2 is applied if the brake operating force of the
brake pedal 72 is less than the resilient force of the braking characteristic setting spring 92 or the equalizer 122 is moved to push the piston rod 73 and to pull the brake rod 62 so that both the front brake BF2 and the rear brake BR2 are applied if the brake pedal 72 is operated by a brake operating force equal to or higher than the resilience of the braking characteristic setting spring 92. Thus, the front-back interlocking brake system can be constructed by adding a small number of parts including the equalizer 122 and the interlocking master cylinder 68 to a motorcycle provided with a brake pedal 72 as a rear brake operating member, and a mechanical rear brake BR2. [0 0 5 6]
A front-rear interlocked brake system in a fifth embodiment according to the present invention will be described with reference to Figs. 18 and 19. Fig. 18 is a partly sectional diagrammatic view of the front-rear interlocked brake system and Fig. 19 is an enlarged longitudinal sectional view of a front master cylinder. [0 0 5 7]
The front-rear interlocked brake system has a front brake lever 62 for applying a hydraulic front brake BF2, and
a brake pedal 72 capable of simultaneously applying both the front brake BF2 and a mechanical rear brake BR2 when a certain brake operating force is applied thereto. The brake pedal 72 is connected by a connecting rod 61 to an equalizer 122 having one end connected to an interlocking brake operating force transmission system 44 and the other end connected to a brake rod 62 connected to the rear brake
BR2-
[0 0 5 8]
The front brake Br2 is operated by an output liquid pressure of a front master cylinder 45' operated by the front brake lever 62. The front brake BF2 is connected by a line 87 to a liquid pressure chamber 86 of the master cylinder 45' in which a master piston 85 operates. [0 0 5 9]
The interlocking brake operating force transmitting system 44 comprises a braking characteristic setting spring 92 compressed between a stop ring 75 and a flange 73a, an
interlocking master cylinder 68 to be operated by an equalizer 122, and a line 83 connected to a liquid pressure
chamber 71 formed in the interlocking master cylinder 68. The line 83 is connected to the interlocking master
cylinder 68 so that a liquid pressure produced in the liquid chamber 86 of the front master cylinder 45' when the master piston 85 of the front master cylinder 45' operates may not be applied to the interlocking master cylinder 68. In the front master cylinder 45', an annular supply chamber 91 is defined by the inner circumference of the cylinder body 88, the outer circumference of the master piston 85 and a pair of cup seals 89 and 90. The cylinder body 88 is provided with a release port 92 and a supply port 93, which are connected through the pipe 79 to the reservoir tank 80. The release port 92 opens into the liquid pressure chamber 86 when the master piston 72 is retracted to its rearmost position, and the supply port 93 is always open into the supply chamber 91. The line 83 of the interlocking brake operating force transmitting system 44 is connected to the front master cylinder 45' so as to be connected to the release port 92 and the supply port 93. [0 0 6 0]
In the fifth embodiment, both the front brake Br2 and the rear brake BR2 can simultaneously be applied by operating the brake pedal 72 by an operating force equal to or higher than a predetermined operating force determined
by adjusting the braking characteristic setting spring 92 when the front brake lever 62 is not operated and the piston 85 of the front master cylinder 45' is at its rearmost position. The fifth embodiment is able to exercise the same effects as those exercised by the fourth embodiment, and enables the reduction of the number of parts because the interlocking master cylinder 86 and the front master cylinder 45' are able to share the reservoir tank 80 combined with the interlocking master cylinder 86. [0 0 6 1]
Fig. 20 shows a front-rear interlocked brake system in a sixth embodiment according to the present invention, in which parts like or corresponding to those of the foregoing embodiments are designated by the same reference characters. [0 0 6 2]
The front-rear interlocked brake system has a front brake lever 63 for applying a hydraulic front brake BF2, and a brake pedal 72 capable of simultaneously applying both the front brake Br3 and a mechanical rear brake BR2 when a certain brake operating force is applied thereto. The brake pedal 72 is connected by a connecting rod 61 to an
equalizer 122 having one end connected to an interlocking brake operating force transmission system 45 and the other end connected to a brake rod 62 connected to the rear brake
BR2'
[0 0 6 3]
The interlocking brake operating force transmitting system 45 has an interlocking cable 10 connected to one end
of the equalizer 122, and a push lever 96 having a base end pivotally supported by a shaft 95 at a fixed position to apply a pressure to a piston included in a front master cylinder 45 connected to the front brake BF2. The interlocking cable 10 is connected to a free end of the push lever 96. A braking characteristic setting spring 93 is compressed between a lug 97 formed integrally with the front master cylinder 45, and the free end of the push lever 96, i.e., a component part of the interlocking brake operating force transmitting system 45. [0 0 6 4]
The front brake lever 63 and the push lever 96 are supported for turning on a shaft 95. The push lever 96 is provided with a projection 96a with which the front brake lever 63 engages to apply a pressure to the piston of the
front master cylinder 45 when operated for braking. [0 0 6 5]
In the sixth embodiment, only the push lever 96 can be turned, leaving the front brake lever 63 at an inoperative position, to make the front master cylinder 45 apply a liquid pressure to the front brake Br2 by operating the brake pedal 72 by a brake operating force equal to or higher than a predetermined operating force determined by adjusting the braking characteristic setting spring 93. Thus, both the front brake BF2 and the rear brake BR2 can simultaneously be applied in a front-rear interlocked braking mode. The sixth embodiment exercises the same effects as those of the fourth and the fifth embodiment, and needs less component parts than the fourth and the fifth embodiment because the sixth embodiment does not need any master cylinder corresponding to the interlocking master cylinder 68. [0 0 6 6]
Although the preferred embodiments of the present invention has been described, the present invention is not limited in its practical application to those embodiments specifically described herein, and many changes and
variations are possible therein without departing from the scope and spirit thereof as set forth in the appended claims. [0 0 6 7]
[Effect of the Invention]
According to the inventions stated in claims 1 to 9, the front brake is applied to produce a braking force by operating the front brake operating member for a braking operation without operating the rear brake operating member. When the rear brake operating member is operated for a braking operation and the front brake operating member is not operated, only the rear brake is applied if the brake operating force applied to the rear brake operating member is less than a force corresponding to the resilience of the braking characteristic setting spring or both the rear and the front brake are applied in a front-rear interlocked braking mode if the brake operating force applied to the rear brake operating member is equal to or higher than the force corresponding to the resilience of the braking characteristic setting spring. Thus, only the rear brake produces a relatively low braking force in an initial stage of a brake operating operation, and the
front-rear interlocked brake system has a simple construction. [0 0 6 8]
According to the invention stated in claim 3, the equalizer is unable to turn on the joint of the equalizer and the connecting member in a direction to reduce the rear brake operating force transmitted by the rear brake operating force transmitting member. Therefore, the braking force of the rear brake can surely be secured when the rear brake operating member is operated even if the interlocking brake operating force transmitting system is broken accidentally. [0 0 6 9]
According to the inventions stated in claims 5 to 9, in a vehicle in which the rear brake operating member is a brake pedal and the rear brake is of a mechanical type, the front-rear interlocked brake system can easily be constructed by adding the least necessary number of parts to the vehicle. Particularly, according to the invention stated in claim 9, the front-rear interlocked brake system does not need any interlocking master cylinder, which is necessary for the inventions stated in claims 6 to 8, the
number of parts necessary for constructing the front-rear interlocked brake system can further be reduced.
[REFERENCE CHARACTERS]
41, 42, 43, 44, 45 ... Interlocking brake operating force
transmitting systems 61, 62, 63 ... Front brake levers (Front brake operating
members) 7i ... Rear brake lever (Rear brake operating member) 72 ... Brake pedal (Rear brake operating member) 9i/ ^2/ ^3 ••• Braking characteristic setting springs
10 ... Interlocking cable
11 ... Rear brake cable (Rear brake operating force
transmitting member 12l, 122 ... Equalizers 28 ... Lower holder (Fixing member) 33 ... Connecting member (Component of interlocking brake
operating force transmitting system) 42 ... Connecting member 42a ... Stopper
45, 45' — Front master cylinders 62 ... Brake rod (Rear brake operating force transmitting
member 63i, 632 — First caliper pistons
64 ... Second caliper piston
68 ... Interlocking master cylinder
73 — Piston rod (Component of an interlocking brake
operating force transmitting system) 75 ... Stop ring (Fixing member)
85 ... Master piston
86 ... Liquid pressure chamber
96 ... Push lever (Component of interlocking brake
operating force transmitting system)
97 ...Lug (Fixed member)
BF1, BF2, BF3 ••• Front brakes
BR1, BR2 ... Rear brakes

WE CLAIMS
[Claim 1] A front-rear interlocked brake system for a vehicle, comprising: a front brake operating member (6l, 62, 63) to apply a front brake (BF1, BF2, BF3) in response to a brake applying operation; and a rear brake operating member (71, 72) capable of applying both a rear brake (BRJ, B^) and the front brake (BF1, BF2, BR3); the improvement comprising: a component member (33, 73, 96) of an interlocking brake operating force transmitting system (41, 42, 43, 44, 45) capable of transmitting a brake operating force applied to the rear brake operating member (71,72) to the front brake (BF1, BF2, BF3); a fixed member (28, 75, 97) fixed to a body; and a braking characteristic setting spring (91, 92, 93) for applying a force acting in a direction opposite the direction in which the rear brake operating member ((7l, 72) applies a force to the interlocking brake operating force transmitting system (41,
42, 43, 44, 45), disposed between the component member (33, 73, 96) of the interlocking brake operating force transmitting system (4l, 42, 43, 44, 45), and the fixed
member (28, 75, 97).
[Claim 2] The front-rear interlocked brake system according to claim 1, wherein the rear brake operating member (71, 72) is connected to a substantially middle portion of an equalizer (12l, 122), one end of the interlocking brake operating force transmitting system (4l, 42, 43, 44, 45) and one end of a rear brake operating force transmitting member (11, 62) connected to the rear brake (BR1, BF2) are connected to opposite end portions of the equalizer (121, 122), respectively, and the equalizer (121, 122) is capable of turning on the joint of the equalizer (121, 122) and the interlocking brake operating force transmitting system (41, 42, 43, 44, 45) which exerts a brake operating force through the rear brake operating force transmitting member (11, 62) on the rear brake (BR1, BF2) when the brake operating force of the rear brake operating member (71, 72) is less than a force corresponding to the force of the braking characteristic
setting spring (91, 92, 93), and of driving the front brake (BF1, BF2, BF3)through the interlocking brake operating force transmitting system (41, 42, 43, 44, 45) and driving the rear brake (BR1, BR1) through the rear brake operating force transmitting member (11, 62) when the brake operating force of the rear brake operating member ((7l, 72) is not lower than a force corresponding to the force of the braking characteristic setting spring ((91, 92, 93).
[Claim 3] The front-rear interlocked brake system for a vehicle, according to claim 2, wherein the rear brake operating member (7i) is connected by a connecting member (42) to the equalizer (12i), and the connecting member (42) is provided with a stopper (42a) that engages with the equalizer (12i) in a direction to stop the turning of the equalizer (12i) on a joint of the equalizer (12i) and the connecting member (42) in a direction to reduce the force transmitted through the rear brake operating force transmitting member (11).
[Claim 4] The front-rear interlocked brake system for a vehicle, according to claim 3, wherein the interlocking brake operating force transmitting system (41) has an interlocking cable (10) having one end connected to
the equalizer (121) and the other end connected to the front brake operating member (61), and capable of transmitting a brake operating force the rear brake operating member (71) to the front brake operating member (61).
[Claim 5] The front-rear interlocked brake system for a vehicle, according to claim 2, wherein the rear brake operating member (72) is a brake pedal, the rear brake operating member (72) is connected to a substantially middle portion of the equalizer (122), the interlocking brake operating force transmitting system (43, 44, 45) is connected to one end of the equalizer (122)/ and the mechanical rear brake (BR2) is connected through the rear brake operating force transmitting member (62) to the other end of the equalizer (122).
[Claim 6] The front-rear interlocked brake system for a vehicle, according to claim 2, the interlocking brake operating force transmitting system (43, 44) is provided with an interlocking master cylinder (68) interlocked with the equalizer (122) and capable of producing a liquid pressure to be applied to the hydraulic front brake (BF2,
BF3).
[Claim 7] The front-rear interlocked brake system for a vehicle, according to claim 6, wherein the hydraulic front brake (BF3) is a disk brake comprising a first caliper piston (631, 632) operated by a liquid pressure produced by a front master cylinder (45) according to the operation of the front brake operating member (62), and a second caliper piston (64) operated by a liquid pressure produced by the interlocking master cylinder (68).
[Claim 8] The front-rear interlocked brake system for a vehicle, according to claim 6, wherein the interlocking master cylinder (68) is connected to a hydraulic system interconnecting a liquid pressure chamber (86) in which the master piston (85) of a front master cylinder (45') operated by the front brake operating member (62) is placed and the front brake (BF2) so as to inhibit the exertion of a liquid pressure produced in the liquid pressure chamber (86) by the master piston (85) on the interlocking master cylinder (68).
[Claim 9] The front-rear interlocked brake system for a vehicle, according to claim 5, wherein the interlocking brake operating force transmitting system (45)
comprises an interlocking cable (10) having one end connected to the equalizer (122), and a front master cylinder (45) which produces a liquid pressure to be applied to the hydraulic front brake (BF2) when operated by pulling the interlocking cable (10) or the operation of the front brake operating member (63).
10. A. front-rear interlocked brake system for a vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

742-del-1997-abstract.pdf

742-del-1997-claims.pdf

742-del-1997-complete specification (granted).pdf

742-del-1997-correspondence-others.pdf

742-del-1997-correspondence-po.pdf

742-del-1997-description (complete).pdf

742-del-1997-drawings.pdf

742-del-1997-form-1.pdf

742-del-1997-form-13.pdf

742-del-1997-form-19.pdf

742-del-1997-form-2.pdf

742-del-1997-form-4.pdf

742-del-1997-form-6.pdf

742-del-1997-gpa.pdf

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Patent Number

232819

Indian Patent Application Number

742/DEL/1997

PG Journal Number

13/2009

Publication Date

27-Mar-2009

Grant Date

21-Mar-2009

Date of Filing

25-Mar-1997

Name of Patentee

HONDA GIKEN KOGYO KABUSHIKI KAISHA

Applicant Address

1-1, MINAMIAOYAMA 2-CHOME, MINATO-KU, TOKYO, JAPAN.

Inventors:

#	Inventor's Name	Inventor's Address
1	KANAU IWASHITA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.
2	TETSUO TSUCHIDA	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.
3	YUKIMASA NISHIMOTO	C/O KABUSHIKI KAISHA HONDA GIJUTSU KENKYUSHO, 4-1, CHUO 1-CHOME, WAKO-SHI, SAITAMA, JAPAN.

PCT International Classification Number

B62L 3/08

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	HEI-8-067701	1996-03-25	Japan