Title of Invention

FRONT WHEEL STEERING SYSTEM OF MOTORCYCLE

Abstract

A front wheel suspension steering mechanism of a motorcycle (10) for steering a front wheel (18) in which a swing arm (50) is vertically swingably attached on a main frame (11); an axle holder block is clockwise and counterclockwise horizontally rotatably attached on said swing arm; via a kingpin (53) a front wheel (18) is rotatably attached to said axle holder block (54); a knuckle (57) is extended from said axle holder block (54); and a link mechanism (80) is connected at one end to said knuckle (57) and at the other end to a steering stem (70) rotatably mounted to a head pipe (72); said front wheel steering system (73), characterized in that said link mechanism (80) is an L-shaped link which can be folded with the vertical movement of said front wheel with the centerline of said steering stem (70), and that a link portion between the first and second link members (82, 84) of said L-shaped link is a universal joint such as a ball joint.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "A FRONT WHEEL SUSPENSION STEERING MECHANISM OF A MOTORCYCLE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, having a place of business at 1-1 Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan, The following specification particularly describes the invention and the manner in which it is to be performed: GRANTED 23-6-2005 23 JUN 2005 [DETAILED DESCRIPTION OF THE INVENTION] The present invention relates to a front wheel suspension steering mechanism of a motorcycle. [Prior Art] As a technology pertaining to a motorcycle having a swing arm type front suspension system which supports the front wheel and a steering system which steers the front wheel, there has been known a "fender of a motorcycle" disclosed in Japanese Unexamined Patent Publication No. S62-175275 for example. According to Pig. 1 of the patent mentioned above, a swing arm 4 (reference numerals used hereinafter are cited from the patent stated above) is vertically swingably attached. A knuckle arm 7 rotatable in clockwise and counterclockwise directions is attached by a joint 9 on the forward end of the swing arm 4. A front wheel 3 is rotatably attached on the knuckle arm 7, to which one end of the link mechanism (a combined mechanism including members 14 to 18) is connected, and the other end is connected to a handlebar shaft 13 rotatably attached to a handlebar support member 11. [Problem to Be Solved by the Invention] In the prior art motorcycle 1 described above, how to set the position of the front wheel 3 in relation to the position of the handlebar support member 11 (equivalent to the head pipe) is an important factor for determining steering characteristics. Generally, when the vehicle frame is changed in shape and dimensions, the position of the head pipe in relation to the vehicle frame changes longitudinally. With this change, the position of the handlebar shaft 13 (equivalent to the steering stem) rotatably attached to the head pipe also moves longitudinally. When the vehicle frame is changed in shape and dimensions, therefore, it becomes imperative to change the length of the swing arm 4 and the link mechanism. That is, the swing arm 4 and the link mechanism have to be changed every time the vehicle frame is changed. For cost reduction of the motorcycle 1, therefore, the front wheel steering system has possibilities for modification. [Object of the Invention] It is, therefore, an object of the present invention to provide a technology which enables the concurrent use of a swing arm and a link mechanism even if the vehicle frame is subjected to a change, in the motorcycle equipped with a swing arm type front suspension system and a steering system. [Means for Solving the Problem] Accordingly, there is provided a front wheel suspension steering t mechanism of a motorcycle for steering a front wheel in which a swing arm is vertically swingably attached on a main frame; an axle holder block is clockwise and counterclockwise horizontally rotatably attached on said swing arm; via a kingpin a front wheel is rotatably attached to said axle holder block; a knuckle is extended from said axle holder block; and a link mechanism is connected at one end to said knuckle and at the other end to a steering stem rotatably mounted to a head pipe ; said front wheel steering system, characterized in that said link mechanism is an L-shaped link which can be folded with the vertical movement of said front wheel with the centerline of said steering stem, and that a link portion between the first and second link members of said L-shaped link is a universal joint such as a ball joint. The link portion between the first and second link members which make up the L-shaped link is a universal joint. As the steering stem is turned, the front wheel is also turned through the first link member, universal joint, second link member, knuckle, and axle holder block. If the swing angle of the second link member which swings clockwise and counterclockwise together with the knuckle does not agree with the swing angle of the first link member which is swung clockwise and counterclockwise by the steering stem, the deviation of the swing angles is allowed by the universal joint. Therefore, if the centerline of the kingpin is offset from the centerline of the steering stem when the head pipe position has changed in relation to the vehicle frame because of the change of shape and dimensions of the vehicle frame, the offset is allowed by the universal joint, thereby enabling constant smooth operation of the front suspension and steering systems. [Preferred Embodiments of the Invention] The preferred embodiment of the front wheel steering system according to the present invention will be explained with reference to the accompanying drawings. [BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a right side view of a scooter type motorcycle according to the present invention; Fig. 2 is a perspective view showing the front part of the scooter type motorcycle according to the present invention; Fig. 3 is a right side view of a front suspension system and a steering system of the present invention; Fig. 4 is a side view of the front part of the scooter type motorcycle according to the present invention; Fig. 5 is a front sectional view of the front suspension system and the steering system of the present invention; Fig. 6 is an explanatory view (1) showing the function of the front suspension system and the steering system; Fig. 7(a) and 7 (b) are explanatory views (2) showing the function of the front suspension system and the steering system; and Fig. 8(a) and 8(b) are drawings showing an example of modification of the front suspension system and the steering system according to the present invention. In the drawings, the "front", "rear", "left", "right", "upper" and "lower" designations refer to the orientation of he motorcycle in relation to the driver when sitting normally in the driver's seat. Fr indicates front side; Rr, rear side; L, left side; and R, right side . The drawings are to be viewed in the direction of reference numerals. Fig. 1 is a right side view of a scooter-type motorcycle of the present invention. The scooter-type motorcycle 10 (hereinafter referred to simply as the "motorcycle 10") is of such a structure that a main frame 11 including a frame body is arranged at the central lower part; a frame pivot 12 is located at the rear part of the main frame 11; a power unit 14 is vertically swingably attached by a pivot 13 on the frame pivot 12; a rear wheel 15 is attached to the power unit 14, which is suspended from the upper rear part of the main frame 11 by a rear cushion 16; a seat 17 is attached on the upper rear part of the main frame 11; and furthermore a front suspension system 50 supporting the front wheel 18 and another steering system 7 0 than the front suspension system 50 are attached at the front part of the main frame 11. Furthermore, the vehicle body of the motorcycle 10 is enclosed, from the front to the rear, with a front fender 21, a front cover 22, a handle cover 23, a leg shield 24 covering the driver' s leg area, a step floor 25 for resting the driver' s foot, and two rear fenders 26f and 26R, front and rear. In the drawing, reference numeral 31 denotes a mirror; 32, a handlebar; 33, a brake lever; 34, a speedometer; 35, a headlamp; 36, a turn signal lamp; 37, a main stand; 38, a side stand; 39, a storage box serving also as a side cover; 41, a carrier; 42, a tail lamp; 43, an air cleaner; 44, a carburetor; 45, an exhaust pipe; and 46, a muffler. Fig. 2 is a perspective view of the front part of the scooter type motorcycle according to the present invention, showing the front suspension system 50 and the steering system 70. In the front suspension system 50, the base end of a swing arm 52 which is approximately U-shaped in the side view is vertically swingably attached by a pivot 51 to the lower front part of the main frame 11; an axle holder block 54 is attached in a clockwise-counterclockwise rotatable state by a kingpin 53 to the front end of the swing arm 52; and a front wheel 18 is rotatably attached by an axle 55 to an axle holder block 54 . That is, the suspension is of a swing arm type suspension that the swing arm 52 is extended from the front portion of the main frame 11 toward the front of the vehicle body, curving upwardly to the right around the front wheel 18, which is supported cantilevered by the swing arm 52. The steering system 70 is of such a structure that a head pipe post 71 is extended from the front portion of the main frame 11 toward the front upper part; a head pipe 72 is unitarily formed at the front end of the head pipe post 71; and a steering stem 73 is rotatably attached to the head pipe 72, and is connected at the lower end portion 73a to the knuckle 57 through the link mechanism 80. To be more specific, the knuckle 57 is formed integrally with the axle holder block 54 ; the link mechanism 80 is connected at one end to the knuckle 57 and at the other end to the steering stem 73, thereby enabling steering of the front wheel 18. The combined structure of the main frame 11 and the head pipe post 7 makes a vehicle frame 11A. Fig. 3 is a right side view of the front suspension and steering systems of the present invention. The axle holder block 54 has a supported portion (a kingpin mounting portion) 56 formed at the lower rear part for mounting the kingpin 53 . The axle 55 is mounted at center, and the knuckle 57 is extended a little from the axle 55 along the line 0 extending upwardly to the front. The kingpin 53 may be formed integrally with the axle holder block 54 through the supported potion 56. Furthermore, the front suspension system 50 has a shock-absorbing member 61 for absorbing shocks (shocks from the road surface) in the swing direction of the swing arm 52, and a front damper 62 for reducing the amplitude of vibration in the swing direction of the swing arm 52 ; the shock-absorbing member 61 and the front damper 62 being separately mounted. The shock-absorbing member 61 is a resin block capable of deforming elastically to make a spring-like function, and is interposed between the main frame 11 and the swing arm 52, functioning as a spring. The front damper 62 is mounted between the front side portion of the main frame 11 and the midway portion of the swing arm 52. The link mechanism 80 is an L-shaped link which is foldable with the up-down movement of the front wheel 18 (see Fig. 2) , with the link portion 85 between the first and second link members 82 and 84 of the L- shaped link directed f orwardly. To give a detailed description, the link mechanism 80 comprises (1) the first link member 82 one end of which is vertically swingably connected directly to the lower end portion 73a of the steering stem 73 by a first link pin 81, (2) the second link member 84 one end of which is vertically swingably connected directly to the forward end of the knuckle 57 by a second link member pin 83, and (3) a universal joint 86 at which the other ends of the first and second link members 82 and 84 are mutually connected; that is, the first and second link members 82 and 84 are vertically swingably connected at the link portion (joint) 85. The universal joint 86 is for instance a ball joint. The present embodiment is characterized in that the centerline P2 of the king 53 is offset forwardly by the size SI in relation to the centerline PI of the steering shaft 73, and accordingly, the link portion 85 is connected by a universal joint 86. The centerline PI and the centerline P2 are extended forwardly and downwardly nearly in parallel with each other. To explain the positional relation of each member, the lower end portion 73a of the steering stem 73 is located in the upper front part in relation to the pivot 51; the first link pin is positioned in the same position in relation to the lower end portion 73a; the kingpin 53 is disposed in the lower front part in relation to the first link pin 81; the axle 55 is located at the front relative to the kingpin 53; the second link member pin 83 is positioned in the upper front part in relation to the axle 55; and the link portion 85 is disposed in the upper front part in relation to the second link member pin 83. In other words, the second link member pin 83 is disposed in the upper front part in relation to the pivot 51; the link portion 85 is placed in the upper front part in relation to the second link member pin 83; and the lower end portion 7 3a of the steering stem 73 and the first link pin 81 are placed in the upper rear part in relation to the link portion 85. That is, the link portion 85 is located in the vicinity of the forward end portion 57a of the knuckle 57 and in a position (in the upper front part of the knuckle 57) nearly along the line 0. The first link member 82 is a long link extending from the first link pin 81 to the vicinity of the forward end of the knuckle 57, curving downwardly toward the front. The second link member 84 is shorter than the first link member 82. Furthermore, this drawing shows a brake cable 94 and a speedometer cable 98 routed along the link mechanism 80, particularly, along the first link member 82. The brake cable 94 and the speedometer cable 98 are flexible wire-like members installed between the front wheel 18 and the vehicle frame 11A side. To be more specific, the flexible wire-like members 94 and 98 extended from the front wheel side (the axle holder block 54 side) are installed along the first link member 82; and furthermore the first link member 82 is attached along a portion connected to the lower end portion 73a, that is, along the swing center portion of the first link member 82 and further along the head pipe 72 and the steering stem 73. Furthermore, the flexible wire-like members 94 and 98 are attached on the way in the longitudinal direction by a clamp 109 to the first link member 82. The flexible wire-like members 94 and 98 can be passed between the front wheel 18 and the vehicle body side. It is therefore unnecessary to largely deflect the flexible wire-like members 94 and 98 between the front wheel 18 and thevehicle side. Therefore it is possible to easi1y insta 11 the flexible wire-like members 94 and 98 without interfering with the front wheel 18. As is clear from the above explanation, since various types of flexible wire-like members (cables, harnesses, and hoses) installed between the front wheel 18 side and the vehicle frame 11A side run along the link mechanism 80, it is possible to install the flexible wire-like members, thereby-enabling improving external appearance and besides reducing frictional resistance at the time of deflection of the flexible wire-like members. Fig. 4 is a side view of the front part of the scooter type motorcycle according to the present invention, showing the following (1) to (5). (1) Connection of the handlebar 32 to the steering stem 73 . (2) Mounting of the brake lever 33 and the speedometer 34 on the handlebar 32. (3) Mounting of a brake operating arm 93 and a gear box 97 for speed detection on the axle holder block 54 . The gear box 97 is of such a known mechanism that a gear not shown is built and the rotation of the axle 55 is detected through the gear. (4) Connection of the brake lever 33 and the brake operating arm 93 to the brake cable 94. The brake operating arm 93 is for the connection of the inner wire 95 of the brake cable 94. Reference numeral 96 denotes the brake cable outer mounting portion. (5) Connection of the speedometer 34 to the gear box 97 by the speedometer cable 98. When an electric speedometer 34 is employed, the use of a wiring harness in place of the speedometer cable 98 is sufficient. The present invention shows the right side of the link mechanism (the L-shaped link) and the right side of the flexible wire-like members 94 and 98 routed along the link mechanism 80 are covered with a cover 105. Since the link mechanism 80 is an L-shaped link, the cover 105 which covers almost all the L-shaped link is also L-shaped in the side view. It is possible to reduce the amount of an exposed portion of the link mechanism 80 and the flexible wire-like members 94 and 98 by means of the cover 105. Therefore, the link mechanism 80 and the flexible wire-like members 94 and 98 can be effectively protected from outside. Besides, the motorcycle 10 can be improved in external appearance. Furthermore, the drawing shows that the front fender 21 is attached at two points, or at the upper and side portions, by bolts 101, 103, and 103 to the long first link member 82, and the cover 105 is attached at two points on the side by bolts 107 and 108. Details of the mounting structure will be described later on. Fig. 5 is a front sectional view of the front suspension and steering systems according to the present invention, showing the link mechanism 80 conveniently exploded. The brake cable 94 and the speedometer cable 98 shown in Fig. 4 are not shown in this drawing. Fig. 5 shows that the axle holder block 54 is extended to both sides of the vehicle body centerline CL, and that the first link member 82 is extended forward from the lower end portion 73a of the steering stem 73 located at the vehicle body centerline CL, curving to the right around the front wheel 18. Furthermore, Fig. 5 shows a front drum brake 91 mounted between the axle holder block 54 and the hub 18a of the front wheel 18. The front drum brake 91 is of the structure that a brake operating shaft 92 is rotatably attached on the axle holder block 54, and the brake operating arm 93 is attached to the brake operating shaft 92. Now the mounting structure of the front fender and the cover 105 will be explained. The front fender 21 has a stay 21a formed integrally with the upper rear part thereof . The stay 21a is attached by the bolt 101 to the first link member 82, and furthermore attached at the side of the longitudinal intermediate portion by the bolt 103 to the stay 102 of the first link member 82, thereby securely attaching the front fender 21 to the first link member 82. The cover 105 is attached at the side of the lower front part by the bolt 107 to the mounting boss 106 of the first link member 82, and, furthermore, attached at the side of the longitudinal intermediate portion by the bolt 108 to the stay 102 of the first link member 82, thereby fixedly attaching the cover 105 to the first link member 82. Since the front fender 21 and the cover 105 are attached to the long first link member 82 as stated above, no other mounting member such as a stay is needed for attaching them to the vehicle frame 11A (see Fig. 4), thereby simplifying the mounting structure and improving mounting efficiency. Fig. 6 is an explanatory view (1) explaining the operation of the front suspension system and the steering system according to the present invention. With the up- down movement of the front wheel 18 (see Fig. 4), the swing arm 52 and the axle holder block 54 swing up and down in accordance with the amount of the up-down movement of the axle holder block 54. Accordingly the second link member 84 and the first link member 82 connected to the knuckle 57 also swing up and down. The amount of swing of the first link member 82 is smaller than that of the second link member 84 . The first link member 82 is a long link connected at its one end directly to the lower end portion 73a of the steering stem 73, that is, arranged near the steering stem 73 and extended as far as the vicinity of the forward end of the knuckle 57 . The link mechanism 80 therefore makes a much smoother up-down swing than the front suspension system 50, thus gaining a better cushioning performance of the front suspension system. In addition, the cushioning function required by the swing arm type front suspension system 50 and the steering function required by the steering system 70 are performed mutually separately and efficiently. Pigs. 7(a) and 7(b) are explanatory views (2) showing operation of the front suspension system and the steering system according to the present invention. Fig. 7(a) shows the side configuration of the front suspension system 50 and the steering system 70. The centerline P2 of the kingpin 53 is offset forwardly by the size SI with respect to the centerline PI of the steering stem 73. Here, let the point A be the position of the first link pin 81, the point Bo be the position of the link portion 85, the point C be the link position of the kingpin 53 with respect to the swing arm 52, and Xo be the line connecting between the point Bo and the point C. Fig. 7(b) is a plan view further schematically showing the front suspension system 50 and the steering system 70 which are shown in Fig. 7(a) . When the steering stem 73 is at the steering angle of zero, that is, in neutral position, the point A, the point Bo, the point C and the line Xo are all on the vehicle body centerline CL. When the steering stem 73 is turned to turn the first link member 82 counterclockwise from the neutral position by the steering angle αl, the point Bo moves to the point BL. As a result, the line Xo swings on the center of the point C, moving to the line. XL connecting the point BL with the point C. The turning angle from the line Xo to the line XL is (3 1 . On the other hand, when the first link member 82 is turned clockwise from the neutral position by the steering angle al, the point Bo moves to the point BR, causing the line Xo to swing on the center of the point C and reach, the line XR connecting the point BR with the point C. The turning angle from the line Xo to the XR is J3l. As is clear from the above explanation, the centerline P2 of the kingpin 53 is offset forward by the amount of offset SI with respect to the centerline PI of the steering stem 73. Therefore, in Fig. 7 (b) , the point C is located in a position removed forward from the point A by the distance S10. Since the point C is located forward of the point A, the turning angle 01 is larger than the steering angle al (αl The distance S10 changes with the change of the amount of offset SI, thereby allowing a change in the ratio of the turning angle 01 to the steering angle αl. Figs. 8(a) and 8(b) give examples of modifications of the front suspension system and the steering system of the present invention. Fig. 8(a) shows the side configuration of the front suspension system 50 and the steering system 70. In the modification, the centerline P2 of the kingpin 53 is offset backward by the size S2 in relation to the centerline PI of the steering stem 73 by changing the position of the head pipe 72 in relation to the vehicle frame 11. The size and arrangement of the front suspension system 50 and the size of the link mechanism 80 are the same as the structure shown above in Fig. 7(a). Fig. 8(b) is a schematic plan view further showing the front suspension system 50 and the steering system 70 shown in Fig. 8(a). When the steering stem 73 is at the steering angle of zero, that is, in neutral position, the points A, Bo, and C and the line Xo are all on the vehicle body centerline CL. When the steering stem 73 is turned to turn the first link member 73 counterclockwise from the neutral position by the steering angle α2, the point Bo moves to the point BL. As a result, the line Xo swings on the center of the point C, reaching the line XL connecting the point BL with the point C. The turning angle from the line Xo to the line XL is (3 2. In the meantime, when the first link member 82 is turned clockwise from the neutral position by the steering angle α2, the point Bo moves to the point BR. Consequently, the line Xo swings on the center of the point C, reaching the line XR connecting the point BR with the point C. The turning angle from the line Xo to the line XR is β2. As is clear from the above explanation, the centerline P2 of the kingpin 53 is offset backward by the amount of offset S2 in relation to the centerline PI of the steering stem 73. In Fig. 8(b) , therefore, the point C is removed backward from the point A by the distance S20. Since the point C is located to the rear of the point A, the turning angle β2 is smaller than the steering angle α2 (α2>β2) . Therefore, the steering force by the steering stem 73 is small as compared with that in the case the centerline P2 of the kingpin 53 is not offset. The distance S20 is changed simply by changing the amount of offset S2 . Consequently, the ratio of the turning angle β2 to the steering angle α2 can be changed. As described above, the turning angle βl varies with respect to the steering angle al, and the turning angle β2 varies with respect to the steering angle a2 . Therefore, the link portion 85 is connected by means of the universal joint 86. That is, if the turning angle (swing angle) βl or β2 of the second link member which swings clockwise and counterclockwise together with the knuckle 57 does not agree with the steering angle (the swing angle) al or a2 of the first link member 82 which swings clockwise and counterclockwise as the steering stem 73 is turned, the swing angle deviation is allowed by the universal joint 86. Therefore, if the centerline P2 of the kingpin 53 is offset from the centerline PI of the steering stem 73 when the position of the head pipe 72 relative to the vehicle frame 11 has changed with a change in the shape and size of the vehicle frame 11, the offset is allowed by the universal joint 86. Therefore, the link mechanism 80 operates very smoothly, thus enabling smooth operation of the front suspension system 50 and the steering system 70. Therefore, if the position of the head pipe 72 is changed in relation to the vehicle frame 11, the front suspension system 50 and the link mechanism 80 can be simplified in configuration, easily enabling the common use of the swing arm 50 and the link mechanism 80. Furthermore, the steering characteristics, that is, the steering angle characteristics (the ratio of the turning angle of the front wheel 18 relative to the steering angle of the steering stem 73) and the steering force characteristics (the characteristics of the steering force required for turning the front wheel 18 by the steering stem 73) of the steering system 70 can freely be set by setting the offsets SI and S2 . As a matter of course, it is possible to operate the steering system 70 at normal steering characteristics simply by setting the amount of offsets SI and S2 at zero (S1 = 0, S2 = 0) . It should be noticed that, in the embodiments of the present invention heretofore described, the motorcycle 10 is not limited to the scooter type motorcycle. The universal joint 86 may be a constant velocity joint for connection between the first and second link members 82 and 84 parallelly arranged, or may be a ball joint, a universal joint, or their equivalent. The centerline P2 of the kingpin 53 may be arbitrarily arranged in parallel with the centerline PI of the steering stem 73. [Effect of the Invention] The present invention, being of the above-described configuration, has the following advantage. According to claim 1 the centerline of the kingpin is offset from the centerline of the steering stem. The link mechanism is provided with a foldable L-shaped link which operates correspondingly to the up - down movement of the front wheel. The link portion between the first and second link members that make up the L-shaped link is a universal joint such as a ball joint; therefore if the clockwise and counterclockwise swing angles.of the second link member do not agree with those of the first link member, a swing angle deviation is allowed by the universal joint. Therefore, if the kingpin centerline is offset from the centerline of the steering stem when a change is made in shape and size of the vehicle frame, the offset is allowed by the universal joint. The front suspension system and the steering system can be smoothly operated at all times, thereby enabling simplification of the configuration, and easy common use, of the swing arm and link mechanism. Because of the possibility of common use, components integration and accordingly cost reduction of the motorcycle can be realized. Furthermore, it is possible to freely set the turning characteristics (turning angle characteristics and turning force characteristics) of the steering system by setting the amount of offset of the kingpin centerline relative to the steering stem centerline. Furthermore, since the link mechanism which allows the offset is made up of the first and second link members and only one universal joint connecting between the first and second link members, the link mechanism has a simple configuration. [Explanation of Reference Numerals] 10 . . . motorcycle; 11A . . . vehicle body (vehicle frame) ; 11 . . . main frame; 18 . . . front wheel; 50 . . . front suspension system; 52 ... swing arm; 53 ... kingpin; 54 ... axle holder block; 57 . . . knuckle; 7 0 . . . steering system; 72 . . . head pipe; 7 3 ... steering stem; 80 ... link mechanism; 82 . . . first link member; 84 . . . second link member; 85 . . . link portion; 86 . . . universal joint; P1 . . . centerline of steering stem; P2 . . . centerline of kingpin; al, a2 ... steering angle (swing angle); 01, (3 2 ... turning angle (swing angle). WE CLAIM: 1. A front wheel suspension steering mechanism of a motorcycle (10) for steering a front wheel (18) in which a swing arm (50) is vertically swingably attached on a main frame (11); an axle holder block is clockwise and counterclockwise horizontally rotatably attached on said swing arm; via a kingpin (53) a front wheel (18) is rotatably attached to said axle holder block (54); a knuckle (57) is extended from said axle holder block (54); and a link mechanism (80) is connected at one end to said knuckle (57) and at the other end to a steering stem (70) rotatably mounted to a head pipe (72); said front wheel steering system (73), characterized in that said link mechanism (80) is an L-shaped link which can be folded with the vertical movement of said front wheel with the centerline of said steering stem (70), and that a link portion between the first and second link members (82, 84) of said L-shaped link is a universal joint such as a ball joint. 2. A front wheel suspension steering mechanism of a motorcycle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings. Dated this 5th day of May, 2000. [RITUSHKA NEGI] Of REMFRY & SAGAR ATTORNEY FOR THE APPLICANT

Documents:

415-mum-2000-cancelled pages(23-06-2005).pdf

415-mum-2000-claims(granted)-(23-06-2005).pdf

415-mum-2000-claims(granted)-(23-6-2005).doc

415-mum-2000-correspondence(23-06-2005).pdf

415-mum-2000-correspondence(ipo)-(13-02-2007).pdf

415-mum-2000-drawing(23-06-2005).pdf

415-mum-2000-form 1(05-05-2000).pdf

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

415-mum-2000-form 2(granted)-(23-06-2005).pdf

415-mum-2000-form 2(granted)-(23-6-2005).doc

415-mum-2000-form 3(05-05-2000).pdf

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

415-mum-2000-form 3(23-06-2005).pdf

415-mum-2000-form 5(05-05-2000).pdf

415-mum-2000-petition under rule 137(23-06-2005).pdf

415-mum-2000-petition under rule 138(23-06-2005).pdf

415-mum-2000-power of authority(04-09-2000).pdf

415-mum-2000-power of authority(23-06-2005).pdf

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