Title of Invention

A CHAIN CASE STRUCTURE FOR A REAR WHEEL IN A MOTORCYCLE

Abstract

A chain case structure (80) for a rear wheel in a motorcycle wherein an engine (21) is mounted on a vehicle body frame (11), the rear wheel is secured to said vehicle body frame vertically movably through a swing arm (23), and a chain (64) stretched between a driving sprocket (61) disposed on said engine side and a driven sprocket (63) disposed on said rear wheel side (24) is covered, said chain case structure comprising: a case cover (81) attached to said engine to cover a front portion of said chain; a rear case attached to said swing arm (23) to cover a rear portion of the chain; and an intermediate shielding plate (91) attached to said swing arm to shield between a rear end of said case cover and a front end of said rear case (82); wherein rear portion of said case cover is provided with a rib extending nearly vertically when seen in side view and toward a center of a vehicle body, said intermediate shielding plate is extended forward until it goes over said rib in side view, and said rib and said intermediate shielding plate are arranged in T shape in plan view.

Full Text

FORM 2 THE PATENTS ACT, 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "A CHAIN CASE STRUCTURE FOR A REAR WHEEL IN A MOTORCYCLE" Original 60/mum/2000 14 JUN 2005 HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan, GRANTED 14-6-2005 The following specification particularly describes the nature of the invention and the manner in which it is to be performed:- The present invention relates to a chain case structure for a rear wheel in a motorcycle [Prior Art] As power transfer methods in final reduction gearings, out of power transfer mechanisms for the transfer of power from an engine to a rear wheel in a motorcycle, there are known a chain drive method, a belt drive method, and a shaft drive method. According to the chain drive method/ a rear wheel is secured to a vehicle body frame through a swing arm and power is transmitted from a transmission connected to an output side of the engine to the rear wheel through a chain. In connection with such a chain drive method there is known, for example, "a chain case in a motorcycle" which is disclosed in Japanese Unexamined Utility Model Publication No. Sho 62-5434. [0003] In this prior art, as shown in Figs. 2 to 4 thereof, an engine 4 is mounted on a vehicle body (the reference numeral was quoted from the above publication and this is also the same in the following), a rear wheel 3 is secured to the vehicle body through a rear fork 2, and a sprocket 5 disposed on the engine side 4 and a sprocket 6 disposed on the rear side 3 are connected together through a chain 7. The sprocket 5 on the engine 4 side and-a front-portion of the chain 7 are covered . -.. sideways with an engine case 9,/while the sprocket 6 on the rear wheel 3 side and the remaining portion of the chain 7 are covered with a chain case 8. The chain case 8 is adapted to swing vertically together with the fork 2, centered on a pivot shaft 1. A front end of the chain case 8 and a rear end of the engine case 9 are sealed by overlapping. (Problem to be Solved by the Invention] According to a certain type of a motorcycle, the distance from a center of the sprocket 5 on the engine 4 side up to a center of the pivot shaft 1, which distance will hereinafter be referred to as "wheel base," is sometimes changed at the stage of design. But in the foregoing prior art, the sizes and mounting positions of the chain case 8 and the engine case 9 are always constant. Therefore, as the wheel base increases, there no longer is any overlapped portion between the front end of the chain case 8 and the rear end of the engine case 9, giving rise to a gap. This is not desirable in point of appearance because the chain 7 is seen from the gap. If the front end of the chain case 8 or the rear end of the engine case 9 is extended so as to prevent the formation of such a gap, it is required that the chain case 8 or the engine case 9 be changed every time the wheel base is changed. In this case, however, the freedom of design is low and there is room for improvement. Accordingly, it is an object of the present invention to provide a technique which makes it possible to easily cover between the rear end of the case cover and the front end of the rear case even if the distance from a center of a driving sprocket to a swing center of a swing arm is changed. [Means for Solving the Problem] According to claim 1, in order to achieve the above-mentioned object, there is provided a chain case structure for a rear wheel in a motorcycle wherein an engine is mounted on a vehicle body frame, the rear wheel is secured to the vehicle body frame vertically movably through a swing arm, and a chain stretched between a driving sprocket disposed on the engine side and a driven sprocket disposed on the rear wheel side is covered, the chain case structure comprising a case cover attached to the engine to cover a front portion of the chain, a rear case attached to the swing arm to cover a rear portion of the chain, and an intermediate shielding plate attached to the swing arm to shield between a rear end of the case cover and a front end of the rear case. Even if the distance from the center of the driving sprocket to the swing center of the swing arm is changed so as to become large, the intermediate shielding plate can cover between the rear end of the case cover and the front end of the rear case, thus providing a good appearance of the motorcycle. Besides, it is not necessary to change the design of the case cover and that of the rear case or replace them. In claim 2, in combination with claim 1, a rear portion of the case cover is provided with a rib extending nearly vertically when seen in side view and toward a center of a vehicle body, the intermediate shielding plate is extended forward until it goes over the rib in side view, and a T shape is formed by the rib and the intermediate shielding plate in plan view. Since in plan view the rib, which is in the shape of a vertical plate, and the intermediate shielding plate are arranged in T shape, it is easy to let the tip of the rib on a stationary side approach a side face of the intermediate shielding plate on a movable side. Therefore, it is possible to diminish the gap between the vertical plate like rib and the intermediate shielding plate. A smaller gap provides a better appearance of the motorcycle. Therefore, the present invention relates to a A chain case structure for a rear wheel in a motorcycle in which an engine is mounted on a vehicle body frame, the rear wheel is secured to said vehicle body frame vertically movably through a swing arm, and a chain stretched between a driving sprocket disposed on said engine side and a driven sprocket disposed on said rear wheel side is covered, said chain case structure comprising: a case cover attached to said engine to cover a front portion of said chain; a rear case attached to said swing arm to cover a rear portion of the chain; and an intermediate shielding plate attached to said swing arm to shield between a rear end of said case cover and a front end of said rear case; wherein rear portion of said case cover is provided with a rib extending nearly vertically when seen in side view and toward a center of a vehicle body, said intermediate shielding plate is extended forward until it goes over said rib in side view, and said rib and said intermediate shielding plate are arranged in T shape in plan view. Fig. 1 is a left side view of a motorcycle according to the present invention. A motorcycle 10, which is a two-passenger motorcycle, comprises a body frame 11, a front fork 13 secured to a head pipe 12 of the body frame 11 so as to be rotatable right and left, a front wheel 14 and a front fender 15 both secured to the front fork 13, a handle 16 connected to the front fork 13, a handle cover 17 which covers the handle 16, a power unit 22 with an engine 21 mounted centrally of the body frame 11, a swing arm 23 mounted to a rear portion of the body frame 11, a rear wheel 24 mounted to a rear portion of the swing arm 23, a rear cushion 2 5 which suspends the rear portion of the swing arm 23 , a seat 2 6 mounted at an upper position of the rear portion of the body frame 11, and a body cover 40 which covers the body frame 11. The body frame 11 comprises a single main pipe 31 located centrally of the vehicle width and extending backwardly downward, a rear pipe 32 bonded to a rear end of the main pipe 31 and extending backwardly upward, and a reinforcing pipe 3 3 for reinforcing the bonded portion of the main pipe 31 and the rear pipe 32. The seat 26 is a double seat having a seat portion on which the rider and a passenger can sit. The body cover 40 comprises a front cover 41 which covers a front portion of the head pipe 12, leg shields 42 for covering the leg portions of the driver, a center cover 43 which covers the body frame 11 from the central portion of the body frame 11 to the rear portion thereof, side covers 44 which cover side faces of the body frame 11, and a rear fender 45 which covers an upper portion of the rear wheel 24. In the figure, the numeral 51 denotes a head lamp, numeral 52 denotes a carrier, 53 denotes a bar-like step for the rider, 54 a shift pedal, 55 a main stand, 56 a bar-like auxiliary step, 57 a side cover for the rear wheel, and 58 a tail lamp. Fig. 2 is a left side view of the power unit and the swing arm both used in the invention. Using a clutch and a transmission (neither shown) which are incorporated in a unit case 22a, the power unit 22 changes the magnitude of power of the engine 21 and outputs the thus-changed power from an output shaft 22b. The power unit 22 is mounted to the body frame 11 with two mounting bolts 27. The swing arm 23 is a rear fork for the rear wheel, mounted to a lower end portion of the rear pipe 32 vertically swingably through a pivot shaft 3 5 and extending backward. Therefore, the rear wheel 24 (see Fig. 1) is vertically movable with respect to the body frame 11. In the motorcycle 10, a final reduction gearing 60 in the power transfer mechanism for the transfer of power from the engine 21 to the rear wheel 24 is constituted as a chain drive type. The final reduction gearing 60 comprises an engine-side driving sprocket 61 mounted on the output shaft 22b, a rear wheel-side driven sprocket 63 mounted on a rear wheel axle 62, and a chain 64 stretched between the driving sprocket 61 and the driven sprocket 63. The distance (hereinafter referred to as "wheel base") from a center O1, which is also a center of the output shaft 22b, to a center 02 of the pivot shaft 3 5 is X. The final reduction gearing 60 thus constructed is surrounded with a chain case 80. The chain case 80 comprises a case cover 81 mounted on the engine 21 side, namely, on the unit case 22a for covering front portions of the driving sprocket 61 and the chain 64, a rear case 82 attached to the swing arm 23 for covering rear portions of the driven sprocket 63 and the chain 64, and an intermediate shielding plate 91 attached to the swing arm 23 for covering between a rear end of the case cover 81 and a front end of a rear case 82. In this figure, the case cover 81 is mounted to the unit case 22a with two bolts 85. Fig. 3 is an exploded perspective view of the swing arm and the intermediate shielding plate both used in the present invention. The swing arm 23 comprises a pair of right and left supported pipes 71 fitted on the pivot shaft 35 which is shown in phantom, a pair of right and left side members 72 extending .backward respectively from the right and left supported pipes 71, a cross member 73 mounted between the right and left side members 72 in the vicinity of the pivot shaft 35, and right and left gusset plates 74 for reinforcing the connections between the right and left side members 72 and the cross member 73. The side members 72 are pipes of a rectangular section which are long in the longitudinal direction, while the cross member 73 is a pipe of a rectangular section which is long in the transverse direction. The right and left gusset plates 74 are triangular members when seen in plan view and are secured to rear corners of the side members 72 and the cross member 73 . The triangular members are each a U-shaped member in a vertical sectional view comprising an upper horizontal plate, a lower horizontal plate and a vertical plate. At a front end portion of each triangular member, the cross member 73 is sandwiched between the upper and lower horizontal plates and is thus joined to the triangular member, while a side end portion of each triangular member is abutted against the back (the vehicle body center side) of the associated side member 72. The swing arm 23 is characterized in that a positioning piece 75 parallel to the side members 72 extends backward from the cross member 73. The positioning piece 75 is a vertical plate-like member disposed from the back side of the left side member 72 toward the center of the vehicle body through a predetermined spacing. The reason why the positioning piece 75 is disposed on the left-hand side is that the chain 64 passes the left-hand side. In this embodiment, the positioning piece 75 close to the left side member 72 is joined to the left gusset plate 74. The swing arm 2 3 is further characterized in that a shielding plate stay 76 extends forward from the left side member 72 where the chain 64 passes. More specifically, the shield plate stay 76, which is in the shape of a vertical plate, is extended forward from the left supported pipe 71. In a side face of the shielding plate stay 76 and in a position spaced a predetermined distance Y forward from the pivot shaft center 02 there are formed a first cutout portion 76a which is open upward, a bolt hole 76b, and a second cutout portion 76c which is open downward, successively in this order from above. r The left side member 72 is provided with an upper cover stay 77 extending upward from an upper surface of a front portion thereof and a lower cover stay 7 8 extending downward from a lower surface of the front portion thereof. The upper and lower cover stays 77, 78 are vertical plates positioned in the longitudinal direction of the side member 72. The mark 04 stands for a center of a rear wheel axle. The intermediate shielding plate 91 is a vertically bisplit member comprising an upper half 92 and a lower half 93 , and a front end portion of a longitudinally elongated shield extension 94 is formed integrally at rear end portions of the upper and lower halves 92, 93. The shield extension 94 is a vertically bifurcated member capable of being opened and closed vertically, centered on a rear end thereof. A combined structure of the intermediate shielding plate 91 and the shield extension 94 constitutes a shielding member 90. The shielding member 90 is a resin product formed of a polypropylene resin for example. The following description is now provided about a detailed construction of the shielding member 90. Fig. 4 is a left side view of the shielding member. The intermediate shielding plate 91 is a vertical plate located ahead of a shaft insertion center O3 (corresponding to the pivot shaft center 02 shown in Fig. 3) and is vertically divided in two into the upper half 92 and the lower half 93 with respect to the center 03. The upper half 92 and the lower half 93 are generally symmetric with respect to a horizontal line H passing through the shaft insertion center O3. In side faces of the upper and lower halves 92, 9 3 and on a vertical line Z spaced a predetermined distance Y forward from the shaft insertion center 03 there are formed three holes 91a, 91b and 91c. More specifically, the hole 91a is a bolt insertion hole positioned on a horizontal line H passing through the shaft insertion center 03 and the holes 91b and 91c are pawl engaging holes formed in upper and lower positions vertically with respect to the bolt insertion hole 91a. These three holes 91a, 91b and 91c are through holes. The shield extension 94 comprises a cylindrical portion 95 which is vertically bisected with respect to the horizontal line H passing through the shaft insertion center 03 and an elongated extending portion 96 extending backward from the outer periphery of the cylindrical portion 95. The extending portion 96 comprises an upper plate 96a, a lower plate 96b, and a rear vertical plate 96c mounted between a rear end of the upper plate 96a and that of the lower plate 96b. The extending portion 96 is formed with a first flange portion 96d on its left-hand side (this side in the figure) and a second flange portion 96e on its right-hand side (the opposite side in the figure). The shield extension 94 is elastically deformable so that it can be opened and closed vertically (in arrow V directions) with the rear vertical plate 96c as a base end. Fig. 5 is a plan view of the shield member 90, showing that gripping portions 96f extend outwards of the vehicle body from upper and lower positions of the first flange portion 96d, namely, from upper and lower surfaces of the shield extension 94 (only the upper gripping portion 96f is shown). Fig. 6 is a view as seen in the direction of arrow 6 in Fig. 4, showing that the upper half 92 and the lower half 93 are vertically aligned with each other. The upper half 92 comprises a thick-wall portion 91d, a tapered portion 91e formed above the thick-wall portion, and a thin wall portion 91f, all of which are located above the horizontal line H. The lower half 93 is of the same shape as the upper half 92 . This figure also shows that the cylindrical portion 95 wanes on its vehicle body center side (left-hand side in the figure) with respect to the intermediate shielding plate 91 when seen in front view. Turning back to Fig. 3, an explanation of the shielding member 90 will be continued. The cylindrical portion 95 has an inside diameter of a size which permits the insertion therein of each supported pipe 71. The spacing between the gripping portions 96f is equal to the thickness of each side member 72 and has a size which permits the cross member 73 to be inserted therein. The rear vertical plate 96c is an oblique member in plan extending in parallel with the slant face of the left gusset plate 74. Fig. 7 is a left side view of a front half portion of the chain case according to the present invention, showing that the rear end portion of the case cover 81, the front end portion of the rear case 82 and the intermediate shielding plate 91 are superimposed together in front of the pivot shaft 35. More specifically, a front portion of the rear case 82 is partially inserted into a rear portion of the case cover 81 and a gap S1 formed between a rear end 81a of the case cover 81 and a front end 82a of the rear case 82 is covered with the intermediate shielding plate 91. The rear case 82 and the shielding member 90 both mounted to the swing arm 23 are vertically swingable together with the swing arm 23. Fig. 7 further shows that a reinforcing rib 81b extending nearly vertically in side view is formed at the rear portion of the case cover 81 and that the intermediate shielding plate 91 is extended forward (leftward in the figure) until going over the rib 81b in side view. By fixing the upper half 92 and the lower half 93 of the intermediate shielding plate to the shielding plate stay 76 (see Fig. 3) through a connecting member 101 in front of the pivot shaft 35, the intermediate shielding plate 91 can be secured to the swing arm 23. Fig. 8 is a plan view of a front half portion of the chain case according to the present invention, showing the following constructional points (1) to (3): (1) The pivot shaft 35 is inserted into a supporting pipe 34 of the body frame 11 to support the swing arm 23. (2) The shield extension 94 is extended backward along a back 72a of the left side member 72 and the rear vertical plate 96c is disposed along the slant face of the left gusset plate. (3) As the rib 81b formed on the inner surface of the case cover 81 extends toward a vehicle body center CL, it forms T shape in plan view in cooperation with the intermediate shielding plate 91. Fig. 9 is a sectional view taken on line 9-9 in Fig. 7, showing that the rear case 82 is a vertically bisected case consisting of an upper case 83 and a lower case 84, whereby the chain 64 is covered. Fig. 9 further shows that the shield extension 94 is passed between the back 72a of the left side member 72 and the positioning piece 75 and is thereby established its position in the transverse direction (right and left direction in the figure). More specifically, the positioning of the shield extension 94 can be done by sandwiching the first and second flange portions 96d, 96e in between the back 72a of the left side member 72 and the positioning piece 75. Further, by sandwiching outer side plates 83a and 84a of the upper and lower cases 83, 84 in between the back 72a of the left side member 72 and the first flange portion 96d and by allowing the inner surface of the second flange portion 96e to receive inner side plates 83b and 84b of the upper and lower cases 83, 84, it is possible to effect positioning of the rear case 82 in the transverse direction. By bringing a lower end face of the upper case 83 into abutment against an upper surface of the gusset plate 74 and an upper end face of the lower case 84 into abutment against a lower surface of the gusset plate 74, it is possible to effect positioning of the rear case 82 in the vertical direction. Fig. 10 is a sectional view taken on line 10-10 in Fig. 7, showing that a vertical positioning of the shield extension 94 can be done by sandwiching the upper and lower surfaces of the left side member 72 in between the gripping portions 9 6f which extend outwards of the vehicle body from the upper and lower surfaces of the shield extension 94. The gripping portions 96f have through holes 96g respectively for passage therethrough of the upper and lower cover stays 77, 78. The stays 77 and 78 are for mounting the outer side plates 83a and 84a of the upper and lower cases 83, 84 with bolts 104. Nuts 105 are attached respectively to the upper and lower cover stays 77, 78. Fig. 11 is a sectional view taken on line 11-11 in Fig. 7, showing a fixing structure for the upper half 92 and the lower half 93. More specifically, the upper and lower halves 92, 93 are sandwiched between the shielding plate stay 76 and the connecting member 101, and upper and lower pawls 101a, 101c of the connecting member 101 are brought into engagement with the first and second cutout portions 76a, 76c to restrict a vertical opening between the upper and lower halves 92, 93. Further, a bolt 102 is inserted into the bolt hole 101b of the connecting member 101 and the connecting member, the shielding plate stay 76 and the upper and lower halves 92, 93 are tightened together with the bolt 102, whereby the upper and lower halves 92, 93 can be bolted to the shielding plate stay 76. Numeral 103 denotes a nut attached to the shielding plate stay 76. Fig. 12 is a sectional view taken on line 12-12 in Fig. 7, showing that the front portions of the driving sprocket 61 and the chain 64 are covered with the case cover 81. The case cover 81 comprises a left side plate 81d, an upper plate 81e and a lower plate 81f. The case cover is generally inverted U-shaped when seen in a sectional rear view and is open in the longitudinal direction (the paper surface and back direction of the figure) Fig. 12 also shows that a tip 81c of the rib 81b is positioned close to the left side face of the intermediate shielding plate 91 through a gap S2 having a spacing 3 . Since the vertical plate-like rib 81b and the intermediate shielding plate 91 are arranged in T shape in plan view, it is easy to draw the tip 81c of the rib 81b on the stationary side close to a side face of the intermediate shielding plate 91 on the movable side. Therefore, it is possible to decrease the gap S2 between the rib 81b and the intermediate shielding plate 91. Since the gap S2 is small, the appearance of the motorcycle is improved. Figs. 13(a) to 13(c) are diagrams for explaining the operation of the chain case structure for a rear wheel according to the present invention. Fig. 13(a) shows that the distance from the center O1 of the driving sprocket 61 to the center 02 of the pivot shaft 35, namely, wheel base, is X1. In this case, the gap S1 between the rear end 81a of the case cover 81 and the front end 82a of the rear case 82 can be covered by the intermediate shielding plate 91. Fig. 13(b) shows that the wheel base is X2 and is smaller than the above wheel base X1 In this case, the gap S1 can be covered by the same intermediate shielding plate 91 as in the above Fig. 13(a). Fig. 13(c) shows that the wheel base is X3 and is larger than the above wheel base X1 In this case, by replacing the intermediate shielding plate 91 with a larger one, the gap S1 can be covered with the larger plate. Thus, even if a change is made to a larger wheel base, the gap between the rear end of the case cover 81 and the front end of the rear case 82 can be covered easily by the intermediate shielding plate 91. As is apparent from the above (a) to (c) , even if the wheel base is changed to X1 to X3,the gap S1 between the rear end 81a of the case cover 81 and the front end 82a of the rear case 82 can be covered easily by the intermediate shielding plate 91. Therefore, the appearance of the motorcycle can be maintained in a good condition. Besides, the degree of design freedom is high because it is not necessary to change the design of the case cover 81 and that of the rear case 82 or replace them. Next, a mounting procedure for the shielding member of the above construction will be described below with reference to Fig. 3. (1) First, while the shield extension 94 is manually opened vertically with the rear vertical plate 96c as a base end (Arrow the shielding member 90 is moved forward along the left side member 72 (Arrow (2)) . As a result, the shaft insertion center 03 of the shield member 90 can be made coincident with the pivot shaft center 02 while the intermediate shielding plate 91 and the shield extension 94 cross the cross member 3 and the left gusset plate 74. (2) Next, the through holes 96g are registered with the upper and lower cover stays 77, 78 (Arrow (D) and the hand is released, allowing the shield extension 94 to revert to its original form by its self-restoring force. As a result, a position of the shielding member 90 in the vehicle width direction is determined, and by sandwiching the upper and lower surfaces of the left side member 72 in between the gripping portions 96f there is determined a position of the shielding member 90 in the vertical direction. In this state, the intermediate shielding plate 91 (the upper half 92 and the lower half 93) overlaps the left side face of the shielding plate stay 76. (3) Next, the connecting member 101 is brought into contact with the upper and lower halves 92, 93 (Arrow ©) and the upper and lower pawls 101a, 101c of the connecting member 101 are brought into engagement with the first and second cutout portions 76a, 76c, respectively to restrict the vertical opening of the upper and lower halves 92, 93. Further, the connecting member 101 and the upper and lower halves 92, 93 are both fixed to the shielding plate stay 76 with a single bolt 102 . The mounting work for the shielding member 9 0 is now completed. [Effect of the Invention] The constitution of the present invention described above brings about the following effects. Since the chain case of claim 1 comprises a case cover attached to an engine to cover a front portion of a chain, a rear case attached to a swing arm to cover a rear portion of the chain, and an intermediate shielding plate attached to the swing arm to shield between a rear end of the case cover and a front end of the rear case, even if the distance from a center of a driving sprocket to a swing center of the swing arm is changed so as to become larger, the space between the rear end of the case cover and the front end of the rear case can be covered easily by the intermediate shielding plate. Consequently, the appearance of the motorcycle can be maintained in a good condition. Besides, the degree of design freedom is enhanced because it is not necessary to change the design of the case cover and of the rear case or replace them. In claim 2, a rear portion of the case cover is provided with a rib extending nearly vertically when seen in side view and toward a center of a vehicle body, the intermediate shielding plate is extended forward until it goes over the rib in side view, and the rib and the intermediate shielding plate are arranged in T shape in plan view, therefore, it is easy to draw the tip of the rib on a stationary side close to a side face of the intermediate shielding plate on a movable side. Consequently, it is possible to diminish the gap between the rib which is like a vertical plate and the intermediate shielding plate. By diminishing the gap it is possible to provide an effective blindfold from the exterior, so the appearance of the motorcycle concerned can be made better. Besides, since the rib of the case cover also serves as a blindfold member, it is not necessary to attach any special blindfold member to the case cover. [Explanation of Reference Numerals] 10 . , . motorcycle, 11 . . . body frame, 21 . . - engine, 22 ... power unit, 23 ... swing arm, 24 ... rear wheel, 35 ... pivot shaft, 61 . . . driving sprocket, 63 ... driven sprocket, 64 . . . chain, 71 . . . supported pipe, 72 . . . side member, 73 ... cross member, 75 ... positioning piece, 76 . . . shielding plate stay, 80 . . . chain case, 81 . . . case cover, 81b . . . rib, 82 . . . rear case, 91 . . . intermediate shielding plate, 92 ... upper half, 93 ... lower half, 94 ... shield extension, 96f . . . gripping portion, 102 . . bolt, S1 ... gap, O1 ... center of the driving sprocket, 02 . . . center of the swing arm (center of the pivot shaft) , X . . . wheel base WE CLAIM: A chain case structure (80) for a rear wheel in a motorcycle wherein an engine (21) is mounted on a vehicle body frame (11), the rear wheel is secured to said vehicle body frame vertically movably through a swing arm (23), and a chain (64) stretched between a driving sprocket (61) disposed on said engine side and a driven sprocket (63) disposed on said rear wheel side (24) is covered, said chain case structure comprising: a case cover (81) attached to said engine to cover a front portion of said chain; a rear case attached to said swing arm (23) to cover a rear portion of the chain; and an intermediate shielding plate (91) attached to said swing arm to shield between a rear end of said case cover and a front end of said rear case (82); wherein rear portion of said case cover is provided with a rib extending nearly vertically when seen in side view and toward a center of a vehicle body, said intermediate shielding plate is extended forward until it goes over said rib in side view, and said rib and said intermediate shielding plate are arranged in T shape in plan view. A chain case structure for a rear wheel in a motorcycle substantially as herein described with reference to the accompanying drawings. Dated this 19th day of January, 2000. [RITUSHKA NEGI] [RITUSHKA NEGI] OF REMFRY & SAGAR ATTORNEY FOR THE APPLICANTS

Documents:

60-mum-2000-claims(granted)-(14-06-2005).doc

60-mum-2000-claims(granted)-(14-06-2005).pdf

60-mum-2000-correspondence(22-03-2006).pdf

60-mum-2000-correspondence(ipo)-(14-06-2004).pdf

60-mum-2000-drawing(14-06-2005).pdf

60-mum-2000-form 1(14-06-2005).pdf

60-mum-2000-form 1(19-01-2000).pdf

60-mum-2000-form 19(15-04-2004).pdf

60-mum-2000-form 2(granted)-(14-06-2005).doc

60-mum-2000-form 2(granted)-(14-06-2005).pdf

60-mum-2000-form 3(19-01-2000).pdf

60-mum-2000-form 3(23-02-2001).pdf

60-mum-2000-form 5(19-01-2000).pdf

60-mum-2000-petition under rule 138(14-06-2005).pdf

60-mum-2000-power of authority(11-04-2000).pdf

60-mum-2000-power of authority(14-06-2005).pdf

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