Title of Invention

"MOTORCYCLE SEAT MOUNTING STRUCTURE"

Abstract

A motorcycle seat mounting structure, with a bottom plate of a seat supported on a vehicle frame via a cushioning member, for coupling an upper stay projecting downwards from the bottom plate and an opposing lower mounting stay projecting upwards from the side of the vehicle frame in such a manner that relative vertical movement is possible, wherein a resilient buffer is interposed between the upper mounting stay and the lower mounting stay-

Full Text

[Detailed Description of the Invention] [Field of the Invention] The present invention relates to a motorcycle seat mounting structure for maintaining operativity of a vertical coupling unit for coupling a seat and a vehicle frame so as to be capable of being moved vertically with respect to each other. [Prior Art] In Japanese Patent Laid-open Publication Hei. 6-312677, a seat base plate is supported on a vehicle frame via a cushion member and a motorcycle seat mounting structure is provided with a vertical coupling unit provided between an upper side mounting stay projecting downwards from a base plate side and a lower side mounting stay projecting upwards from an opposing vehicle frame side coupling in such a manner as to enable relative vertical movement of the seat base plate and the vehicle frame. [Problems This Invention Sets Out To Solve] With this vertical coupling unit, when a heavy person sits on the seat so that the shape of the base plate is changed, there is direct contact with and rocking at the lower side mounting stay due to the upper side mounting stay dropping down and as a result, the relative movement becomes stiff. [Means for Solving the Problems] In order to resolve the aforementioned problem, in the invention for a motorcycle mounting structure of this application, there is provided a motorcycle seat mounting structure, with a bottom plate of a seat supported on a vehicle frame via a cushioning member, for coupling an upper stay projecting downwards from the bottom plate and an opposing lower mounting stay projecting upwards from the side of the vehicle frame in such a manner that relative vertical movement is possible, wherein a resilient buffer is interposed between the upper mounting stay and the lower mounting stay. When the upper mounting stay drops down due to deformation of the bottom plate, this drop is absorbed by elastic deformation of the interposed buffer member and rocking due to direct contact with the lower mounting stay is prevented. Therefore, superior operation of the vertical coupling unit can be maintained even if the upper mounting stay drops down. Accordingly, the present invention relates to a motorcycle seat mounting structure, with a bottom plate of a seat supported on a vehicle frame via a cushioning member, for coupling an upper stay projecting downwards from the bottom plate and an opposing lower mounting stay projecting upwards from the side of the vehicle frame in such a manner that relative vertical movement is possible, wherein a resilient buffer is interposed between the upper mounting stay and the lower mounting stay. [Brief Description of the Drawings] FIG. 1 is a cross-sectional view of the vertical coupling unit. FIG. 2 is a left side view relative to the direction of travel of the external appearance of the motorcycle. FIG. 3 is a perspective plan view of enlarged portions thereof. FIG. 4 is a cross-sectional view of essential parts showing the mounting state of the seat. FIG. 5 is a view showing the top surface of the rear. FIG. 6 is a view of the bottom surface of the seat. FIG. 7 is a side view of the shape of the cushioning rubber. FIG. 8 shows the shape when viewed from above. FIG. 9 shows an example modification thereof. FIG. 10 is an assembly diagram relating to the second embodiment. FIG. 11 is a side view of this resilient buffer. FIG. 12 is an assembly diagram relating to the third embodiment. FIG. 13 is an assembly diagram relating to the fourth embodiment. [EmbodimentsJ The following is a description based on the drawings of an embodiment of the present invention applied to a motorcycle. FIG. 2 is a left side view relative to the direction of travel of the external appearance of the motorcycle, and FIG. 3 is a perspective plan view of enlarged portions thereof. This motorcycle is of an American style configuration, being provided with a front wheel 1 and a rear wheel 2 forming a long wheel base, a front fork 3 of a large caster angle, drop-style handle bars 4, and a teardrop-type fuel tank 5, a tandem seat 6 mounted at a relatively low position, to the rear of which is provided a back reclining chair 7. plate 20 in the side view, passes through the pivot plate 20 and connects with a cross pipe 21 (FIG. 2) extending in the direction of the vehicle width. The rear part of the vehicle frame consists of seat rails 22 extending to the rear as an approximately horizontal left and right pair from the curved part of the upper pipe upper pipe 17 so as to support the tandem seat 6 and a side frame 23 connected to the lower pipe 18 and extending towards the rear from the side of the pivot plate 20 in such a manner as to be inclined upwards and be connected to the central part of the seat rails 22. {00+33 At the pivot plate 20, the front end of a rear fork 24 is supported so as to be capable of rocking freely up and down at a pivot axle 25. This rear fork 24 extends to the rear, with the rear wheel 2 being supported in a freely rotatable manner at the rear end~thereof. A buffer 26 is provided between a coupling unit for the seat rails 22 and the side frame 23 and the rear end of the rear fork 24. The rear wheel 2 is chain driven by a chain 29 wound between a driven sprocket 27 provided so as to be concentric with the side surface of the rear wheel and a drive sprocket 28 for the engine 8. Numeral 30 in the drawings represents a carrier, numeral 31 represents a rear fender, numeral 32 represents a tail lamp, numeral 33 represents a mudguard, numeral 34 represents a rear indicator, and numeral 35 represents a rear number plate. Next, a description is given of the seat mounting structure. FIG. 1 is a cross-sectional view showing the vertical coupling unit, FIG. 4 is a cross-sectional view of essential parts showing the mounting state of the seat, FIG, 5 is a view showing the top surface of the rear fender and FIG. 6 is a view of the bottom surface of the seat. As shown in FIG. 4, the tandem seat 6 is equipped with a bottom sheet 40 made of resin with an insertion plate 41 formed at the front end thereof so as to protrude in the forward direction and is sealed via rubber 43 provided below a sealing plate 42 extending from the rear end of the fuel tank 5 towards the rear. Cushioning rubber 44 is mounted at the bottom surface of the front half of the bottom sheet 40, with the lower end of this cushioning robber 44 coming into contact with the top of a cross pipe 45 for the sheet rails 22. At the left and right of the central part, an upper side attaching stay 46 is attached in a rigid manner so as to be inclined towards the sides and is coupled to a lower side attaching stay 47 projecting upwards from the seat rail 22 via a resilient buffer 48 so as to form a vertical coupling unit permitting relative vertical movement. -£0620]-- Recesses 49 (FIG. 6) are formed at the rear part of the bottom sheet 40 at a total of four places, i.e. one to the front and rear on both the left and right sides so as to come into contact with the upper end of a cushioning rubber 50 projecting from the side of the rear fender 3 1 . The cushioning rubber 50 is supported on a bridge 52 formed at the upper part of a sub-frame 51 arranged in a sub-assembly at the inside of the rear fender 3 1 . A rear mounting stay 53 is mounted at the rear end of the bottom plate 40 via a rubber 54 and is fastened to an embedded bolt 55 by a nut 56. This rear end extends to the rear of the tandem seat 6, extends to the rear from the bridge 52 and is attached using a bolt 59 to a nut of a mounting plate 58 (same) extending to the rear from the bridge 52 passing through a through hole 57 (FIG. 5) formed in the rear fender 3 1 . As shown in FIG, 1, an elongated hole 61 elongated in the vertical direction is formed in the upper mounting stay 46 at the lower part of a mounting surface 60 (refer to FIG. 6) so as to face outwards at an incline. On the other hand, the lower mounting stay 47 on the opposing coupling side is fixed on the seat rails 22 so as to face in an outward direction in such a manner that the mounting surface 62 becomes parallel with the mounting surface 60. A bolt through hole 63 is then formed at the mounting surface 62 and a weld nut 64 is also provided at this portion. [0625]- The resilient buffer 48 forms an approximate circular plate shape and is made of extremely resilient rubber. A center hole 65 is formed in the center of the resilient buffer 48 and overlaps with the surface of the mounting surface 60 that faces towards the outside. A flanged collar 66 passes through the center hole 65 and the resilient buffer 48 is then interposed between a flanged part 67 and the mounting surface 60. The width of the elongated hole 61 is the outside diameter of the collar 66, while the resilient buffer 48 and the flanged part 67 are of approximately the same diameter and both are larger than the width of the elongated hole 61. Further, the material is by no means limited to rubber and various well known materials can be utilized providing that these materials posses an appropriate degree of resilience. The tip of the collar 66 passes through the elongated hole 61 and comes into contact with the mounting surface 62. The mounting surfaces 60 and 62 are formed at a spacing that is such that there is no contact under normal circumstances and a bolt 68 passing through the collar 66 passes through the through hole 65 and is fastened with a nut 64. FIG. 7 is a side view of the shape of the cushioning rubber 44 and FIG. 8 shows the shape when viewed from above. The cushioning rubber 44 has an umbrella-shaped projection 70 for inserting into and blocking a mounting hole formed at the bottom plate 40 formed as a single body and a plurality of mutually parallel channels 71 hollowed out to approximately half the thickness of the cushioning rubber 44 are formed at the upper surface thereof. Further, a concave part 72 curving upwards is formed at the lower surface thereof. [0029] , As a result, the cushioning characteristics can be changed due to the influence of the channels 71 in such a manner that lightly impacting loads are received in a gentle manner and more forcible loads are received in a firmer manner. Further, as a result of the influence of the concave part 72, similarly, the deformation of the concave parts 72 can be made lighter in the early stages and firmer with respect to large loads. FIG. 9 shows an example modification of the cushioning bar 44 where channels 73 similar to the channels 71 are formed at the lower part in place of the concave parts 72. However, the depth of the channels 71 and 73 is taken to be approximately 1/3 to 1/4 of the thickness. In this way, the channels 73 have the same function as the channels 71 . 400343 Next, a description is given of the operation of a first embodiment. When the vehicle in FIG. 1 vibrates, the tandem seat 6 moves up and down relatively with respect to the side of the seat rail 22 due to the elastic deformation of the cushion covers 44 and 50. At this time, relative vertical motion between the tandem seat 6 and the seat rail 22 is possible due to the relative vertical motion of the collar 66 within the elongated hole 61 between the upper mounting stay 46 and the lower mounting stay 47. When the bottom plate 40 exhibits substantial elastic deformation due to a large load, the upper mounting stay 46 drops down, but as the resilient buffer 48 is interposed between the mounting surface 60 and the flanged part 67 the resilient buffer 48 is elastically deformed, this dropping down is absorbed and direct contact is prevented. Therefore, even when the upper mounting stay 46 drops down, a situation where direct contact is made with the lower mounting stay 47 and rocking occurs is avoided so that superior operation can be maintained during normal operation and adoption as a resin bottom plate for coping with substantial plastic deformations is advantageous. {0034} FIG. 1 0 is a second embodiment of the present invention. In this example, the same resilient buffer 48 as for the previous embodiment is interposed between the mounting surfaces 60 and 62 and a further new second resilient buffer 75 is interposed between the mounting surface 60 and the flanged part 67. The second resilient buffer 75 is also an approximately circular plate shape of approximately the same diameter as the resilient buffer 48 but, as shown in FIG. 11, radiating channels 76 are formed at the surface making contact with the flanged parts 67 to a depth of approximately half the thickness with a through hole 75 being formed at the center thereof. 40036}- In this way, as the resilient buffer 48 and the second resilient buffer 75 are provided at both surfaces of the mounting surface 60, even if the mounting surface drops towards the inside or the outside, this is absorbed by the deformation of one of the resilient buffers 48 and 75. As the second resilient buffers 75 are provided at the outside for the occurrence of extreme drops, the spring rate can be changed by forming channels 76 at the second resilient buffer 75 so that relatively small drops are lightly received by the portion for the channels 76 and large drops are firmly received by the whole of the second resilient buffer 75. The characteristics of the hardness can therefore be changed in response to the size of the vibrations. FIG. 1 is a third embodiment. Here, a resilient buffer 80 constituted by a rubber grommet fitted to within the elongated hole 61 is approximately elliptical in shape, a portion 81 protruding towards the side of the lower mounting stay 47 is of substantially the same structure as the resilient buffer 48 of FIG. 1, and a portion 82 protruding towards the side to which the bolt 68 is attached is of substantially the same structure as the second resilient buffer member 75 of FIG. 10 with the resilient buffer 48 and the second resilient buffer 75 forming a single body. As a result, parts reduction is possible as the resilient buffer 80 can be made as a single body prior to attachment to the mounting surface 60, the number of parts can be further reduced from that of the second embodiment of FIG. 10 and handling can be improved. FIG. 13 is a fourth embodiment where a mounting hole 91 is provided at a mounting part 90 for the bottom plate 40 of the upper mounting stay 46, with a rubber grommet 92 being fitted therein for mounting and with radiating channels 93 that are relatively shallow being formed at both upper and lower surfaces thereof. If this rubber grommet is then attached to the bottom plate 40 by a bolt at the mounting hole 94, even if the bottom plate 40 elastically deforms this is absorbed by the rubber grommet 92 and falling of the mounting surface 60 is prevented. The spring rate can then be varied using the upper and lower channels 93. The second resilient buffer 75 can be used as the resilient buffer provided between the mounting surface 60 and the flanged part 67, as is also the case with the other embodiments. [Key to the Reference Numerals] tandem seat 6; seat rail 22; rear fender 31; bottom plate 40, cushioning rubber 44; upper mounting stay 46; lower mounting stay 47; resilient buffer 48; mounting surface 60; elongated hole 61, mounting surface 62; collar 66; flanged part 67; second resilient buffer 75; rubber grommet 80. We Claim: 1, A motorcycle seat mounting structure, with a bottom plate (40) of a seat supported on a vehicle frame via a cushioning member (44), for coupling an upper stay projecting downwards from the bottom plate (40) and an opposing lower mounting stay (47) projecting upwards from the side of the vehicle frame in such a manner that relative vertical movement is possible, wherein a resilient buffer (48) is interposed between the upper mounting stay (46) and the lower mounting stay (47). 2. A motorcycle seat mounting structure substantially as herein described with reference to the accompanying drawings

Documents:

175-del-1999-abstract.pdf

175-del-1999-claims.pdf

175-del-1999-correspondence-others.pdf

175-del-1999-correspondence-po.pdf

175-del-1999-description (complete).pdf

175-del-1999-drawings.pdf

175-del-1999-form-1.pdf

175-del-1999-form-13.pdf

175-del-1999-form-19.pdf

175-del-1999-form-2.pdf

175-del-1999-form-3.pdf

175-del-1999-form-4.pdf

175-del-1999-form-6.pdf

175-del-1999-gpa.pdf

175-del-1999-petition-137.pdf