Title of Invention

"BRAKE SYSTEM FOR VEHICLE"

Abstract

[OBJECT] In a brake system having brake operating members, a plurality of wheel brakes, and a plurality of brake cables for transmitting brake operating forces applied to the brake operating members to the wheel brakes, the plurality of wheel brakes are applied in an interlocked braking mode by operating the brake operating member, and only the specified one of the plurality of wheel brakes is applied in a parking brake applying mode. [CONSTITUTION] A parking brake applying mechanism (44) incorporated into a case (42) holds the specified brake cable (15) among the plurality of brake cables (14, 15) in a braking state and the other brake cable (14) in a nonbraking state when the brake operating force applied to the brake operating member (12) is removed.

Full Text

[DETAILED DESCRIPTION OF THE INVENTION] [0001] [Technical Field of the invention] The present invention relates to a brake system for a vehicle, comprising a brake operating member, a plurality of brake cables for transmitting brake operating forces individually to a plurality of wheel brakes, and an equalizer connecting the brake operating member to the brake cables so as to pull the brake cables when the brake operating member is operated for a braking operation, and operatively contained in a fixed case, and, more particularly, to a brake system suitable for application to a motorcycle. [0002] [Related Art] A brake system*for a vehicle, in which a brake operating force applied to a brake operating member is transmitted through an equalizer to a plurality of brake cables for transmitting brake operating forces to a plurality of wheel brakes is disclosed in, for example JP-A No. 7-196069. [0003] [Problem to be Solved by the Invention] A conventional parking brake for, for example, a motorcycle brings a parking brake lever into engagement with a recess formed in a brake lever, i.e., a brake operating member, to lock the brake lever at a braking position. If such a parking brake is applied directly to such a brake system as the foregoing brake system in which the plurality of wheel brakes are applied when the brake operating member is operated, all the wheel brakes are applied when the parking lever is engaged with the recess of the brake lever and, if the wheel brakes are hydraulic brakes, a liquid pressure acts on the component rubber parts of the wheel brakes, such as pipes and sealing members, to reduce the life of the rubber parts. [0004] The present invention has been made in view of such a problem and it is therefore an object of the present invention to provide a brake system for a vehicle, capable of applying a plurality of wheel brakes in an interlocked braking mode when a brake operating member is operated and of applying only a specified one of the plurality of wheel brakes for a parking brake applying mode to avoid unnecessary application of the wheel brakes. [0005] [Means for Solving the Problem] With the foregoing object in view, according to an invention stated in claim 1, a brake system for a vehicle, comprises: a brake operating member; a plurality of brake cables for transmitting brake operating forces individually to a plurality of. wheel brakes; and an equalizer connecting the brake operating member to the brake cables so as to pull the brake cables when the brake operating member is operated for a braking operation, and operatively contained in a fixed case. A parking brake means is contained in the case to hold one brake cable among the brake cables in a braking state and the other brake cable (15) in a nonbraking state with the brake operating member kept at an inoperative position. [0006] According to an invention stated in claim 2, in the brake system according to the invention stated in claim 1, the parking brake means includes a parking lever contained in the case so as to be movable between an operative position where the parking lever engages with the equalizer moved to an operating position by the braking operation of the brake operating member and an inoperative position where the parking lever is disengaged from the equalizer, and the equalizer is contained in the case so as to be able to move to a position where the equalizer holds the specified brake cable among the brake cables in a braking state and the other brake cable in a nonbraking state when the brake operating force applied to the brake operating i.tember is removed with the equalizer and the parking lever engaged. [0007] According to an invention stated in claim 3, in the brake system according to the invention stated in claim 2, an operating member is supported on the case and operatively connected to the parking lever resiliently biased in a direction from the operative position toward the inoperative position so as to be able to operate the parking lever from outside the case. [0008] According to an invention stated in claim 4, in the brake system according to the invention stated in claim 2 or 3, a parking brake switch for detecting the setting of the parking lever at the operative position is attached to the case. [0009] According to an invention stated in claim 5, in the brake system according to any one of the inventions stated in claims 1 to 4, the case comprises a box formed integrally with a holder attached to a handlebar, and pivotally supporting the brake operating member, and a cover joined to the box so as to cover the open end of the box. [0010] According to an invention stated in claim 6, in the brake system according to any one of the inventions stated in claims 1 to 5, a brake switch is attached to the case, and the switching node of the brake switch changes according to the operation of the equalizer corresponding to the operation of the brake operating member. [BRIEF DESCRIPTION OF THE DRAWINGS] [Fig. 1] Fig. 1 is a view showing the general arrangement of a brake system for a vehicle. [Fig. 2] Fig. 2 is a plan view of a left end portion of a handlebar included in a motorcycle. [Fig. 3] Fig. 3 is a partly cutaway front view taken in the direction of the arrow 3 in Fig. 2. [Fig. 4] Fig. 4 is a sectional view take on line 4-4 in Fig. [Fig. 5] Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 3. [Fig. 6] Fig. 6 is a sectional view of an essential portion of the arrangement of Fig. 3 of assistance in explaining operations in a brake nonoperating state, in which a cover is removed. [Fig. 7] Fig. 7 is a sectional view, similar to Fig. 6, of assistance in explaining operations in a parking brake applying mode. [0011] [Description of the Preferred Embodiments] A preferred embodiment of the present invention will be described hereinafter with reference to the accompanying drawings. [0012] Figs. 1 to 7 show a brake system in a preferred embodiment according to the present invention, in which Fig. 1 is a view showing the general arrangement of the brake system, Fig. 2 is a plan view of a left end portion of a handlebar included in a motorcycle, Fig. 3 is a partly cutaway front view taken in the direction of the arrow 3 in Fig. 2, Fig. 4 is a sectional view take on line 4-4 in Fig. 2, Fig. 5 is an enlarged sectional view taken on line 5-5 in Fig. 3, Fig. 6 is a sectional view of an essential portion of the arrangement of Fig. 3 of assistance in explaining operations in a brake nonoperating state, in which a cover is removed, and Fig. 7 is a sectional view, similar to Fig. 6, of assistance in explaining operations in a parking brake applying mode. [0013] Referring to Fig. 1, the brake system for a vehicle has a front brake lever 11 operated to apply a hydraulic front brake BF, and a rear brake lever 12, i.e., a brake operating member, capable of applying a mechanical rear brake BR and the hydraulic front brake Br in an interlocked braking mode when operated for braking. [0014] The rear brake lever 12 is connected to a substantially middle portion of an equalizer 13, one end of a front brake cable 14 for transmitting a brake operating force to the front brake BF is connected to one end of the equalizer 13, and one end of a rear brake cable 15 for transmitting a brake operating force to the rear brake BR is connected to the other end of the equalizer 13. The other end of the front brake cable 14 is connected to an auxiliary lever 16. [0015] The front brake Br is a disk brake. A master cylinder 18 which produces a liquid pressure when pushed by the auxiliary lever 16 is connected by a line 19 to the front brake BF. The master cylinder 18 is disposed on a right end portion of a handlebar 35 (Figs. 2 to 4) provided in a front portion of the body of a motor scooter. The front brake lever 11 to be operated by the driver's right hand is pivotally supported by a shaft 21 on a bracket 20 provided on the master cylinder 18. The auxiliary lever 16 capable of applying an operating force to the master cylinder 18 is supported pivotally by a shaft 21 on the bracket 20. The auxiliary lever 16 has a portion 16a with which the front brake lever 11 engages when operated for braking. A spring 23 for biasing the portion 16a toward the front brake lever 11, i.e., in a direction to remove the force applied to the master cylinder 18, is extended between a fixed arm 22 fixed to the master cylinder 18, and the auxiliary lever 16. When the front brake lever 11 is operated for braking, the front brake lever 11 engages with the portion 16a to apply a pressure through the auxiliary lever 16 to the master cylinder 18, so that the front brake BF is applied. When the front brake cable 14 is pulled, the auxiliary lever 16 is turned leaving the front brake lever 11 to apply a pressure to the master cylinder 18, so that the front brake BF is applied. [0016] The rear brake BR is a drum brake comprising a brake drum 26 mounted on a rear axle 25, a brake panel 27, a pair of brake shoes 29 pivotally supported by a pin 28 on the brake panel 27 and capable of being brought into frictional contact with the inner circumference of the brake drum 26, a brake cam 30 supported for turning on the brake panel 27 to operate the pair of brake shoes 29 so that the pair of brake shoes 29 are pressed against the inner circumference of the brake drum 26, a brake arm 31 having a base end connected to the brake cam 30 and extending outside from the brake drum 26, a fixed arm 32 disposed opposite to the brake arm 31, and a spring 33 compressed between the brake arm 31 and the fixed arm 32 to bias the brake arm 31 in a direction to allow the brake shoes 29 to move toward each other. The rear brake BR produces a braking force according to a brake operating force applied through the rear brake cable 15 to the brake arm 31. [0017] Referring to Figs. 2 to 4, a grip 36 to be grasped by the driver's left hand is attached to a left end portion of the handlebar 35 provided in a front portion of the body of the motor scooter. A holder 37 is attached to the handlebar 35 at a position on the inner side of the grip 36. The holder 37 has an attaching portion 37a corresponding to substantially half the circumference of the handlebar 35. A circular stay 38 corresponding to the other half circumference of the handlebar 35 has one end engaged with the attaching portion 37a and the other end fastened to the holder 37 with a screw 39 to fasten the holder 37 to the handlebar 35. The rear brake lever 12 has a base end pivotally joined to the holder 37 by a shaft 40. The rear brake lever 12 is operated for braking operation by the left hand gripping the grip 36. [0018] A box 37b having an open upper end is formed integrally with the holder 37, and a flat cover 41 is fastened to the box 37b so as to cover the open upper end of the box 37b. The box 37b and the cover 41 constitute a case 42. The equalizer 13 is contained in the case 42. [0019] Referring to Figs. 5 and 6, a connecting rod 43 has one end connected to the base end of the rear brake lever 12, and is inserted through a side wall 37ba of the box 37b of the case 42 into the case 42 so as to be axially movable. The other end of the connecting rod 43 is joined pivotally to a substantially middle portion of the equalizer 13 so that the equalizer 13 is able to turn on the joint of the connecting rod 43 and the equalizer 13. [0020] The respective sheaths 14a and 15a of the front brake cable 14 and the rear brake cable 15 are arranged side by side on and fixed to a side wall 37b2 opposite the side wall 37bi of the box 37b; that is, in one end of the front brake cable 14 having an inner cable 14b slidably inserted in the sheath 14a, the sheath 14a is fixed to the side wall 37b2 of the box 37b, and an end portion of the inner cable 14b projecting from the sheath 14a into the case 42 is connected to one end of the equalizer 13, and in one end of the rear brake cable 15 having an inner cable 15b slidably inserted in the sheath 15a, the sheath 15a is fastened to the side wall 37b2 of the box 37b beside the front brake cable 14, and an end portion of the inner cable 15b projecting from the sheath 15a is connected to the other end of the equalizer 13. [0021] A brake operating force applied to the rear brake lever 12 is transmitted through the connecting rod 43 to the equalizer 13. The equalizer 13 does not pull the brake cables 14 and 15 and remains at an inoperative position near the side wall 37b2 of the box 37b as shown in Fig. 6 while any brake operating force is not applied thereto by the rear brake lever 12. When a brake operating force is applied to the equalizer 13 by operating the rear brake lever 12, the equalizer 13 is moved away from the side wall 37b2 to an operative position, pulling the brake cables 14 and 15 to apply both the front brake BF and the rear brake BR in an interlocked braking mode. [0022] A parking brake applying mechanism 44 is incorporated into the case 42. The parking brake applying mechanism 44 is capable of holding the rear brake cable 15 at a braking position and of allowing the front brake cable 14 to remain at a nonbraking position with the rear brake lever 12 held at an inoperative position. The parking brake applying mechanism 44 has a parking lever 45 supported pivotally in the case 42 for movement between an equalizer holding position where the parking lever 45 is able to engage with the equalizer 13 moved to the position by the rear brake lever 12, and an inoperative position where the parking lever 45 releases the equalizer 13, and a push button 46, i.e., an operating member, operatively combined with the parking lever 45 to operate the parking lever 45 from outside the case 42. [0023] A shaft 47 is fixed to the base end of the parking lever 45 and the shaft 47 is supported for turning on the cover 41 of the case 42. Thus, the parking lever 45 supported on the case 42 for turning about the axis of the shaft 47. A pin 48 is attached to a free end portion of the parking lever 45. When the equalizer 13 is moved to the position, the pin 48 is able to engage with a recess 13a formed in the other end of the equalizer 13 as shown in Fig. 7. The parking lever 45 is able to turn about the axis of the shaft 47 between an operative position where the pin 48 engages with the recess 13a of the equalizer 13 moved to its position, and an inoperative position where the pin 48 is disengaged from the recess 13a to release the equalizer 13. A torsion spring 49 wound around the shaft 47 has one end engaged with the case 42 and the other end engaged with the parking lever 45. The torsion spring 49 biases the parking lever 45 toward the inoperative position. [0024] If a brake operating force is applied to the rear brake lever 12 to move the equalizer 13 to the operative position, the parking lever 45 is turned to its operative position to bring the pin 48 thereof into engagement with the recess 13a of the equalizer 13, and then the brake operating force is removed from the rear brake lever 12, the equalizer 13 turns to a parking brake applying position, where the equalizer 13 keeps the rear brake cable 15 at its operative position and allows the front brake cable 14 to return to its inoperative position as shown in Fig. 7. [0025] The push button 46 is supported on the box 37b so as to be axially movable with its inner end in contact with a free end portion of the parking lever 45 and its outer end projecting outside from the box 37b. When the push button 46 is pushed in, the parking lever 45 is turned from is inoperative position to its operative position. [0026] The outer end portion of the push button 46 extends through an opening 50a formed in a cowling 50 disposed in the front section of the body of the motor scooter so as to extend over the handlebar 35. A dust seal 51 put on the push button 46 so that flange thereof is in close contact with a portion of the outer surface of the cowling 50 around the opening 50a. [0027] A parking brake switch 52 is attached to the outer surface of the cover 41 of the case 42. A lever 53 is fixed to an end portion of the shaft 47 projecting from the cover 41 so as to be in contact with the actuator 52a of the parking brake switch 52. The lever 53 pushes the actuator 52a when the parking lever 45 is at the inoperative position, and releases the actuator 52a when the push button 46 is pushed to bring the pin 48 of the parking lever 45 into engagement with the equalizer 13. The movement of the parking lever 45 to the operative position can be detected by the parking brake switch 52. [0028] A brake switch 54 is attached to the side wall 37b2 of the box 37b of the case 42 at a position between the front brake cable 14 and the rear brake cable 15. The brake switch 54 assumes different switching positions respectively for a state where the equalizer 13 is at the inoperative position near the side wall 37b2 and a state where the equalizer 13 is at the operative position apart from the side wall 37b2. Thus, an interlocked braking state where the equalizer 13 is at the operative position and both the front brake Br and the rear brake BR are applied can be detected by the brake switch 54. [0029] The actions of this embodiment will be described hereinafter. If only the front brake lever 11 is operated for braking and the rear brake lever 12 is not operated, the auxiliary lever 16 applies a pressure to the master cylinder 18 to apply the front brake Br. [0030] If only the rear brake lever 12 is operated for braking and the front brake lever 11 is not operated, the equalizer 13 moves to the operative position, pulling both the front brake cable 14 and the rear brake cable 15. Consequently, the auxiliary lever 16 moves toward the master cylinder 18, leaving the front brake lever 11 behind to apply a pressure to the master cylinder, so that both the front brake Br and the rear brake BR are applied in an interlocked braking mode. This interlocked braking mode is detected by the brake switch 54. [0031] Both the front brake Br and the rear brake BR can be applied by operating both the front brake lever 11 and the rear brake lever 12. [0032] When carrying out a braking operation for parking, a braking force is applied to the rear brake lever 12 to turn the rear brake lever 12 to the braking position and the push button 46 is pushed to turn the parking lever 45 against the resilience of the torsion spring 49 from the inoperative position to the operative position. Consequently, the pin 48 of the parking lever 45 engages with the recess 13a of the equalizer 13 positioned at its operative position. If the brake operating force is removed from the rear brake lever 12, the equalizer 13 takes the parking brake applying position, where the equalizer 13 keeps the rear brake cable 15 at its operative position and allows the front brake cable 14 to return to its inoperative position as shown in Fig. 7. consequently, only the rear brake BR is applied and the front brake Br is not applied. This parking brake applying mode is detected by the parking brake switch 52. In the parking brake applying mode, any liquid pressure does not act on the component rubber parts of the hydraulic front brake Br, such as pipes and sealing members, so that the life of the component rubber parts of the hydraulic front brake BF is extended. [0033] The parking brake applying mode can be canceled simply by slightly turning the rear brake lever 12 in a brake applying direction; the parking lever 45 is turned from the operative position to the inoperative position by the resilience of the torsion spring 49 to release the equalizer 13 and the equalizer 13 is allowed to return to the inoperative position when the rear brake lever 12 is released free, so that the rear brake BR is released. [0034] Thus, the parking brake applying operation requires only operations for applying a brake operating force to the rear brake lever 12 and pushing the push button 46. Since the parking lever 45, i.e., one of the component parts of the parking brake applying mechanism 44, is contained in the case 42 containing the equalizer 13, and the push button 46, i.e., another component part of the parking brake applying mechanism 44, is supported on the case 42 with one end thereof projecting outside from the case 42, the parking brake applying mechanism 44 has a satisfactory appearance. [0035] The case 42 comprises only the least necessary parts, i.e., the box 37b formed integrally with the holder 37 for holing the rear brake lever 12, and the cover 41 fastened to the box 37b. [0036] Although the preferred embodiment of the present invention has been described. the present invention is not limited in its practical application to the embodiment specifically described herein and many changes and variations in the design thereof are possible without departing from the scope as set forth in the appended claims. [0037] [Effect of the Invention] According to the invention stated in claim 1, since the parking brake means is incorporated into the case to hold one brake cable among the brake cables in a braking state and the other brake cable in a nonbraking state with the brake operating lever kept at an inoperative position, only the specified one of the plurality of wheel brakes can be applied for the parking brake applying mode. Therefore, in the brake system including a hydraulic wheel brake and a mechanical wheel brake, the hydraulic wheel brake can be kept in an inoperative state in the parking brake applying mode to avoid unnecessary application of liquid pressure to the component parts of the hydraulic wheel brake, particularly, rubber parts, so that the life of the rubber parts of the hydraulic wheel brake can be extended. [0038] According to the invention stated in claim 2, in the brake system of the invention stated in claim 1, the parking brake means includes the parking lever contained in the case so as to be movable between the operative position where the parking lever engages with the equalizer moved to the operating position by the braking operation of the brake operating member and an inoperative position where the parking lever is disengaged from the equalizer, and the equalizer is contained in the case so as to be able to move to a position where the equalizer holds the specified brake cable among the brake cables in a braking state and the other brake cable in a nonbraking state when the brake operating force applied to the brake operating member is removed with the equalizer and the parking lever engaged. Thus, at least part of the parking brake applying means is contained in the case and the parking brake applying means has a satisfactory appearance. [0039] According to the invention stated in claim 3, in the brake system of the invention stated in claim 2, the operating member is supported on the case and operatively connected to the parking lever resiliently biased in a direction from the operative position toward the inoperative position so as to be able to operate the parking lever from outside the case. Therefore, the brake can be applied for parking by a simple parking brake applying operation. [0040] According to the invention stated in claim 4, in the brake system of the invention stated in claim 2 or 3, the parking brake switch for detecting the setting of the parking lever at the operative position is attached to the case. Therefore, the parking brake applying mode can easily be detected. [0041] According to the invention stated in claim 5, in the brake system of the invention stated in any one of claims 1 to 4, the case comprises the box formed integrally with the holder attached to the handlebar, and pivotally supporting the brake operating member, and the cover joined to the box so as to cover the open end of the box. Thus, the case can be constructed by assembling the least number of parts. [0042] According to the invention stated in claim 6, in the brake system of the invention stated in any one of claims 1 to 5, the brake switch is attached to the case, and the switching mode of the brake switch changes according to the operation of the equalizer corresponding to the operation of the brake operating member. Therefore, the interlocked braking mode can easily be detected. [REFERENCE CHARACTERS] 12 ... Rear brake lever (Brake operating member) 13 ... Equalizer 14, 15 ... Brake cables 35 ... Handlebar 37 ... Holder 37b ... Box 41 ... Cover 42 ... Case 44 ... Parking brake applying mechanism 45 ... Parking brake lever 46 ... Push button (Operating member) 52 ... Parking brake switch 54 ... Brake switch By, BR ... Wheel brakes WE CLAIM: [Claim 1] A brake system for a vehicle, comprising: a brake operating member (12); a plurality of brake cables (14, 15) for transmitting brake operating forces individually to a plurality of wheel brakes (BF, BR); and an equalizer (13) connecting the brake operating member (12) to the brake cables (14, 15) so as to pull the brake cables (14, 15) when the brake operating member (12) is operated for a braking operation, and operatively contained in a fixed case (42); characterized by a parking brake means (44) contained in the case (42) to hold one brake cable (15) among the brake cables (14, 15) in a braking state and the other brake cable (15) in a nonbraking state with the brake operating member (12) kept at an inoperative position. [Claim 2] The brake system according to claim 1, wherein the parking brake applying means (44) includes a parking lever (45) contained in the case (42) so as to be movable between an operative position where the parking lever (45) engages with the equalizer (13) moved to an operating position by the braking operation of the brake operating member (12) and an inoperative position where the parking lever (45) is disengaged from the equalizer (13), and the equalizer (13) is contained in the case (42) so as to be able to move to a position where the equalizer (13) holds the specified brake cable (15) among the brake cables (14, 15) in a braking state and the other brake cable in a nonbraking state when the brake operating force applied to the brake operating member (12) is removed with the equalizer (13) and the parking lever (45) engaged. [Claim 3] The brake system according to claim 2, wherein an operating member (46) is supported on the case (42) and operatively connected to the parking lever (45) resiliently biased in a direction from the operative position toward the inoperative position so as to be able to operate the parking lever (45) from outside the case (42). [Claim 4] The brake system according to claim 2 or 3, wherein a parking brake switch (52) for detecting the setting of the parking lever (45) at the operative position is attached to the case (42). [Claim 5] The brake system according to any one of claims 1 to 4, wherein the case (42) comprises a box (37b) formed integrally with a holder (37) attached to a handlebar (35), and pivotally supporting the brake operating member (12), and a cover (41) joined to the box (37b) so as to cover the open end of the box (37b). [Claim 6] The brake system according to any one of claims 1 to 5, wherein a brake switch (54) is attached to the case (42), and the switching mode of the brake switch (54) changes according to the operation of the equalizer (13) corresponding to the operation of the brake operating member (12). 7 A brake system for a vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Documents:

741-del-1997-abstract.pdf

741-del-1997-claims.pdf

741-del-1997-correspondence-others.pdf

741-del-1997-correspondence-po.pdf

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

741-del-1997-drawings.pdf

741-del-1997-form-1.pdf

741-del-1997-form-13.pdf

741-del-1997-form-19.pdf

741-del-1997-form-2.pdf

741-del-1997-form-3.pdf

741-del-1997-form-4.pdf

741-del-1997-form-6.pdf

741-del-1997-gpa.pdf

741-del-1997-petition-138.pdf

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