Title of Invention

SELF-SPIGOTTING SILENT GEARS FOR 2 & 3 WHELLER GEARBOXES

Abstract

Self-spigotting silent gears for 2 & 3 wheeler gearboxes, wherein each of the driven gears, which is rotatably mounted on the output shaft for constantly meshing with the corresponding drive gear being an each part of the cluster gear, is provided with at least one cylindrical step either internally or externally or both, on both sides or with at least one cylindrical step both internally and externally respectively on each side, so as to be rotatably contacting through said cylindrical step either cylindrically or flatly or both, with said adjacent driven-gears, whereby a single group formed by all said driven-gears is provided to minimize any movement axially or radially or both.

Full Text

This invention relates to self-sipigotting silent geark for two and three-wheeler gearboxes. As known, in conventional gearbox, each driven-gear (driven gear) is rotatably mounted on the output shaft to be freely rotatable with respect to each other (driven-gears). The each driven-gear is constantly meshing with each drive gear being a part of the cluster gear. The contacts between each driven-gear and other relatively movable parts i.e., output shaft (while not engaging) and other driven-gears (on each side of said driven-gear) are respectively a cylindrical and a side flat (plane) surface only. A collar that is integrally provided on one side of the output shaft and a set of spacer(s) with a circlip provided on its other end limit the axial movement of either each driven-gear or all the driven-gears. Each driven-gear between the collar and the circlip inherently has small clearances both axially and radially with the relatively movable mating surfaces. These clearances are so far inevitable for each driven-gear with other relatively movable parts for capable of being smoothly and freely rotatable with respect to each other. However, these clearances are causing an axial movement or a radial movement or both, due to the disturbances in the corresponding directions during no-load conditions. This unconstrained freeness in both radial and axial directions also causes the vibrations and the rattling noises during the running of other free-driven-gears without any load. Further, these problems enhance due to insufficient ratio of axial bearing width and its bearing diameter of each driven-gear (L/D Ratio) (on output shaft) or with these clearances. Moreover, due to the inherent wearing-out on the relatively movable mating surfaces after a long life of its operation, these' problems further increase,. These problems causing an unpleasant feeling for riders during its operation inherently associate with the conventional gearbox especially for all the scooters. An object of this invention is to provide self-spigotting silent gears for 2 & 3-wheeler gearboxes to minimise the vibrations. Another object of this invention is to provide with minimum rattling noises. A further object of this invention is to provide with minimum unpleasant feeling of its operation. With these and other objects in view, the present invention provides self-spigotting silent gears for 2 & 3-wheeler gearboxes, wherein each of the driven-gears, which is rotatably mounted on the output shaft for constantly meshing with the corresponding drive gear being an each part of the cluster gear, is provided either with a cylindrical step or its plurality either internally or externally or both, on both side or with a cylindrical step or its plurality both internally and externally respectively on each side, so as to be rotatably contacting through said cylindrical step or its plurality either cylindrically or flatly or both, with said adjacent driven-gears, whereby a single housing formed by all said driven-gears is provided to minimise any movement axially or radially or both or any Wobbling action or both by distributing the same to all the driven-gears particularly to any loaded driven-gear being angularly secured with the output shaft for reducing any vibration(s) or with any rattling noise(s). The invention will now be apparent from the following non-limitative description with reference to the accompanying drawings, in which: FIGURE 1 shows a pictorial view of an assembly of self- spigotting silent gears of a gearbox for scooters partly showing their section along its axis; FIGURE 2 shows a half-sectional view of what is shown in FIGURE 1, along its axis; FIGURE 3 shows a exploded view of the parts of said assembly shown in FIGURES 1 and 2; FIGURES 4A to 4D show pictorial views of the self- spigotting silent-gears of the assembly shown in FIGURES 1 to 2. * Referring to the drawings, the driven-gears 1A to ID of the cluster-gear or push-gear are rotatably mounted on the wheel-shaft 2 or output shaft so as to be relatively rotatable with respect to each other in the known way. As known that, each of said driven-gears lA to ID is constantly meshing with the corresponding drive-gear being a part of said cluster-gear (not shown in FIGURES). A collar (not referred by any reference symbol) is provided as an integral part of said wheel-shaft on one side of said wheel-shaft 2. A set of a spacer 3 with a circlip 4 is provided on other free-end of said wheel-shaft 2. The said driven-gears lA to ID are mounted between said set of the spacer 3 and the circlip 4 and said collar to significantly limit any possible axial movement therebetween. A push rod or shifter-pin 5 is axially slidable inside said wheel-shaft 2 and from spacer 3 -end-side. A cross-shaped key 6 axially secured with said shifter-pin 5 is angularly securable with both said wheel-shaft 2 and any one of said driven-gears lA to ID. Thereby, it enables to impart motion from said driven-gear (said one of 1A to ID) to said wheel-shaft 2 for required speed and torque conditions. According to one preferred embodiment of this invention, a driven-gear lA being on the spacer 3-side-end is provided with an internal cylindrical step 7 on collar.side of said driven-gear lA. Second driven-gear IB adjacent to said first driven-gear lA is provided with an external cylindrical step 8 on one side of said second driven-gear IB. The said external cylindrical step 8 is rotatably contacting with said first cylindrical step 7. The second driven-gear IB is also provided with an external cylindrical step 9 (not shown in FIGURE 1) on other side of said second driven-gear IB. The said external cylindrical step 9 is capable of rotatably contacting with an internal cylindrical step 10 being provided on one side of third driven-gear IC. The third driven- gear IC is also provided with an external cylindrical step 11 (not shown in FIGURE 1) to be rotatably contacting with an internal cylindrical step 12 provided on one-side (inner-side or third driven-gear IC-side) of fourth driven-gear ID.' The fourth driven-gear ID is provided with an internal cylindrical step (not referred by any reference symbol) on its other side for capable of being rotatably contacting with said collar. All the said driven-gears lA to ID are both axially and radially secured with respect each other and also with respect to said wheel-shaft 2. They 1A to ID form together a single rigid housing. Further, each of said cylindrical steps 7 to 12 of all the driven-gears lA to ID is defined by both cylindrical and flat contact surfaces. The said both cylindrical and flat-contact surfaces are respectively referred by the reference symbols A and B associating with corresponding numerals 7 to 12 (i.e., by 7A & 7B, 8A & 8B to 12A & 12B). They are shown in FIGURES 1 to 3 and 4A to 4D. Analogous parts are illustrated with same reference symbols in all the FIGURES. The cylindrical-contacts between the successive driven-gears (i.e., first and second IA and IB, second and third IB and IC and third and fourth-driven-gears IC and' ID) are respectively referred by 7A and 8A, 9A and lOA and 1 lA and 12A. These cylindrical-contacts 7A to 12A are capable of being substantially secured any possible radial movements with respect to each other. However, they are smoothly and relatively rotatable with respect to each other. All other free driven-gears excluding any one thereof lA to ID being angularly secured with said wheel-shaft 2 through said cross-shaped key 6, normally tend to radially rattle due to their constant running gear-mesh with corresponding said drive-gears of cluster-gear. But, it is obvious that according to this invention such radial rattling nature (vibrations and noises of said all other free driven-gears) are transmitted to that loaded driven-gear imparting motion to said wheel-shaft 2. Since, said all other free driven-gears are formed a single rigid housing with said loaded driven-gear for radially securing with respect to said loaded driven-gear. Furthermore, the flat contacts 7B and 8B, 9B and lOB and 1 IB and 12B provided between the successive driven-gears that lA and IB, that IB and IC and that IC and ID, are as similar that of said cylindrical contacts. Any possible inherent axial rattling nature (vibrations and noises) of such other free driven-gears are also transmitted (absorbed) to (by) that loaded driven-gear in turn to said wheel-shaft 2 through said cross-shaped key 6 due to their loaded contacts therebetween. Still further, any possible inherent wobbling natures (i.e., oscillations about a radial axis) of such other free-driven-gears are also averted by that loaded driven-gear. Moreover, the total axial length of bearing contact surfaces of each driven-gear is more than that of the conventional one even for the same total axial length of said assembly of all the driven-gears. Because, the axial length of part of bearing 1 contact surface of each driven-gear is overlapping with other, due to their cyhndricai contacting steps. Thereby, it also considerably increases the ratio of the total axial length of bearing contact surfaces of each driven-gear and the bearing contact-diameter (L/D Ratio). Thus, said self-spigotting feature of all said driven-gears by providing by providing cylindrical step(s), minimises the vibrations of said other free driven-gears during its operation. Consequently, it significantly reduces the rattling noises of this gearbox. Thereby, these features also significantly minimise the unpleasant feeling of its operation unlike the conventional gearbox. In a second preferred embodiment of this invention, each said cylindrical contact step is having the plurality on each side of each of said driven-gears lA to ID. Hence, it still enhances the total axial length of the bearing contact surface(s) of each driven-gear for the same total axial length of the assembly of all said driven-gears lA to ID. Thereby, it still enhances the minimisation of said rattling and vs^obbling natures. Further, in a third preferred embodiment of this invention, said internal or external or both cylindrical steps are replaced either by relatively rotatable conical (tapered) contact-surfaces or by relatively rotatable truncated conical contact-surfaces (not illustrated by any FIGURE). This is solving the diametrical clearance problems of said relatively rotatable self-spigotting joints of the followers lA- to ID. Because, very close clearances however minimise the vibrations, rattling noises and the lil<:e but it inherently decreases the relatively and smoothly movable freeness i.e. increases tightness therebetween. consumes more frictional power loss of gearbox. otherwise clearances leave a little bit above vibrations rattling noise-problems. is obvious that said tapered contact surfaces neither problems nor problems. because functions alike conical bearing.> > Further, in a fourth preferred embodiment of this invention, said spacer 3 is replaced by a spring washer either in the form of a diaphragm-type or in any known form. After prolonged life of its operation, the inherent wear-out problems obviously normally increase the clearances and thereby increasing the problems such as vibrations, rattling noises and the like. Now, this spring washer as the replacement of said spacer 3 axially backs up the first driven-gear lA away therefrom and towards the adjacent driven-gears IB. Then, this first driven-gear lA backs up the second driven-gear IB, subsequently the second driven-gear IB backs up the third driven-gear IC and thereby the third driven-gear IC backs up the fourth driven-gear ID towards said collar. Thus, the axial clearances between said circlip 4, the successive driven-gears lA to ID and said collar are uniformly compensated irrespect of the wear-out problems. Even after the prolonged life of its operation, it uniformly performs well as that during the beginning of its operational life. Tn addition, this fourth-preferred embodiment is employed for the above said first, second and third preferred embodiments of this invention or the combination of any two or the combination of the all. However, the application of this fourth embodiment of this invention in both said first and second preferred embodiments, is obviously not capable of solving any vibrations, rattling noises and the like in radial directions. Nevertheless, the application of this fourth embodiment in said third embodiment, is substantially eliminating the above said problems both radially and axially. Since, the axial back up by said spring washer compensates the clearances between said tapered contact surfaces in axial direction. Thus, it uniformly performs well even after the prolonged life-period of its operation (and even during the wear-out problems). Still further, said spacer 3 is also provided between said spring washer and said first driven-gear lA in all the above features. This enhances the axial bearing contact-area between said first driven-gear lA and said spacer 3 thereby minimising the wear-out problem therebetween. The terms and expressions used herein are illustrative and not limitative in any sense. WE CLAIM: 1. Self-spigotting silent gears for 2 & 3-wheeler gearboxes, wherein each of the driven-gears, which is rotatably mounted on the output shaft for constantly meshing with the corresponding drive gear being an each part of the cluster gear, is provided either with a cyUndrical step or its plurality either internally or externally or both, on both side or with a cylindrical step or its plurality both internally and externally respectively on each side, so as to be rotatably contacting through said cylindrical step or its plurality either cylindrically or flatly or both, with said adjacent driven-gears, whereby a single housing formed by all said driven-gears is provided to minimise any movement axially or radially or both or any wobbling action or both by distributing the same to all the driven-gears particularly to any loaded driven-gear being angularly > secured with the output shaft for reducing any vibration(s) or with any rattling noise(s). 2. Self-spigotting silent gears for two & 3-wheeler gearboxes as claimed in claim 1, wherein in any known assembly of the driven- gears being between any known collar of the wheel-shaft or output shaft and any known set of both the spacer and the circlip, a driven- gear being on the spacer-side-end is provided with an internal cylindrical step on collar side of said driven-gear, second driven- gear adjacent to said first driven-gear is provided with an external cylindrical step on its one side so that said external cylindrical step is capable of rotatably contacting with said first cylindrical step, the second driven-gear is also provided with an external cylindrical step on its other side so as to be rotatably contacting with an internal cylindrical step being provided on one side of third driven-gear, the third driven-gear is also provided with an external cylindrical step to be rotatably contacting with an internal cylindrical step provided on one-side (inner-side or third driven-gear-side) of fourth driven-gear, said fourth driven-gear is provided with an internal cylindrical step (not referred by any reference symbol) on its other side for capable of being rotatably contacting with said collar, all the said driven-gears are both axially and radially secured with respect each other with forming together a single rigid housing . 3. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed i in claims 1 and 2, wherein each of said cylindrical steps of all the driven-gears is defined by both cylindrical and flat contact surfaces for capable of being substantially secured any possible radial and axial movements respectively, with respect to each other and also for capable of being smoothly and relatively rotatable with respect to each other. 4. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed in claims 1 to 3, wherein the total axial length of bearing contact surfaces of each driven-gear is more than that of the conventional driven-gear even for the same total axial length of said assembly of all the driven-gears for considerably increasing the ratio of the total axial length of bearing contact surfaces of each driven-gear and the bearing contact-diameter. 5. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed in claims 2 to 4, wherein each said cylindrical contact step is having the plurality on each side of each of said driven-gears to still enhance the total axial length of the bearing contact surface(s) of each driven-gear for the same total axial length of the assembly of all said driven-gears for still minimising said rattling and wobbling natures. 6. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed in claims 1 to 5, wherein said internal or external cylindrical steps or both is (are) replaced either by relatively rotatable conical (tapered) contact-surfaces or by relatively rotatable truncated conical contact-surfaces for capable of leaving neither the rattling > problems nor power loss problems. 7. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed in claims 2 to 6, wherein a slaving means is either provided between said spacer and said circlip or provided as a replacement of said spacer for uniformly compensating the corresponding axial clearance(s) or conical clearance(s) or both between said circlip, the successive driven-gears and said collar irrespect of the wear-out problems. 8. Self-spigotting silent gears for 2 & 3-wheeier gearboxes as claimed in claim 7, wherein said slaving means is a spring washer in the form of a diaphragm nature or any known form. 9. Self-spigotting silent gears for 2 & 3-wheeler gearboxes as claimed in claims 7 to 8, wherein the axial back up by said slaving means is capable of compensating the clearances between said tapered contact surfaces being common to both radial and axial directions or with said axial clearance(s)n for eliminating both rattling and wobbling problems even after the prolonged life-period of its operation. 10. Self-spigotting silent gears for 2 & 3-wheeler gearboxes substantially as herein described and illustrated with respect to the accompanying drawings. I

Documents:

418-mas-1999-abstract.pdf

418-mas-1999-claims filed.pdf

418-mas-1999-claims granted.pdf

418-mas-1999-correspondnece-others.pdf

418-mas-1999-correspondnece-po.pdf

418-mas-1999-description(complete)filed.pdf

418-mas-1999-description(complete)granted.pdf

418-mas-1999-drawings.pdf

418-mas-1999-form 1.pdf

418-mas-1999-form 19.pdf

418-mas-1999-form 26.pdf