Track assembly for an all-terrain vehicle (atv) or other tracked vehicle

Abstract

A track assembly for providing traction to an all-terrain vehicle (ATV) or other tracked vehicle. The track assembly may comprise a wheel device for contacting an inner side of an endless track such that a longitudinal end segment of the endless track turns around the wheel device. The wheel device allows a change in curvature of the longitudinal end segment of the endless track when the longitudinal end segment of the endless track contacts an obstacle on the ground. In some embodiments, the wheel device may comprise a resilient wheel that is elastically deformable. In other embodiments, the wheel device may comprise a wheel carrier carrying a plurality of carried wheels.

1 .- 47 . (canceled) 
     
     
         48 . A track assembly for traction of a vehicle, the track assembly comprising:
 a) a track comprising a ground-engaging outer side for engaging the ground and an inner side opposite to the ground-engaging outer side; and   b) a track-engaging arrangement for driving and guiding the track around the track-engaging arrangement, a bottom run of the track extending under the track-engaging arrangement, the track-engaging arrangement comprising:
 i. a drive wheel for driving the track; and 
 ii. a plurality of guiding wheels contacting the bottom run of the track; 
 wherein: an axis of rotation of a given one of the guiding wheels is movable relative to an axis of rotation of the drive wheel when the track assembly moves on the ground; 
 and the given one of the guiding wheels is resilient to be elastically deformable when the track assembly moves on the ground. 
   
     
     
         49 . The track assembly of  claim 48 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel. 
     
     
         50 . The track assembly of  claim 49 , wherein the given one of the leading idler wheel and the trailing idler wheel is the leading idler wheel. 
     
     
         51 . The track assembly of  claim 50 , wherein: an axis of rotation of the trailing idler wheel is movable relative to the axis of rotation of the drive wheel when the track assembly moves on the ground; and the trailing idler wheel is resilient to be elastically deformable when the track assembly moves on the ground. 
     
     
         52 . The track assembly of  claim 48 , wherein the plurality of guiding wheels includes: a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and a plurality of support wheels disposed between the leading idler wheel and the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         53 . The track assembly of  claim 52 , wherein the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel. 
     
     
         54 . The track assembly of  claim 48 , wherein the given one of the guiding wheels comprises a non-pneumatic tire. 
     
     
         55 . The track assembly of  claim 48 , wherein the given one of the guiding wheels comprises foam. 
     
     
         56 . The track assembly of  claim 55 , wherein the foam is closed-cell foam. 
     
     
         57 . The track assembly of  claim 56 , wherein the closed-cell foam is closed-cell polyurethane foam. 
     
     
         58 . The track assembly of  claim 55 , wherein the foam forms at least part of a periphery of the given one of the guiding wheels. 
     
     
         59 . The track assembly of  claim 53 , wherein an outer diameter of the given one of the leading idler wheel and the trailing idler wheel is greater than an outer diameter of a given one of the support wheels. 
     
     
         60 . The track assembly of  claim 59 , wherein the given one of the leading idler wheel and the trailing idler wheel is wider than the given one of the support wheels in a widthwise direction of the track assembly. 
     
     
         61 . The track assembly of  claim 53 , wherein the given one of the leading idler wheel and the trailing idler wheel is wider than a given one of the support wheels in a widthwise direction of the track assembly. 
     
     
         62 . The track assembly of  claim 49 , wherein: the track-engaging arrangement comprises a frame supporting the leading idler wheel and the trailing idler wheel; and a width of the given one of the leading idler wheel and the trailing idler wheel in a widthwise direction of the track assembly occupies at least a majority of a distance between a lateral surface of the given one of the leading idler wheel and the trailing idler wheel and a center of the frame in the widthwise direction of the track assembly. 
     
     
         63 . The track assembly of  claim 48 , wherein: the inner side of the track comprises a plurality of wheel-contacting projections for contacting at least one of the drive wheel and the guiding wheels; and a width of the given one of the guiding wheels in a widthwise direction of the track assembly is greater than a dimension of a given one of the wheel-contacting projections in the widthwise direction of the track assembly. 
     
     
         64 . The track assembly of  claim 63 , wherein the plurality of wheel-contacting projections comprises a plurality of drive projections and the drive wheel comprises a sprocket for engaging the drive projections. 
     
     
         65 . The track assembly of  claim 49 , wherein: the given one of the guiding wheels is a first given one of the guiding wheels; an axis of rotation of a second given one of the guiding wheels is movable relative to the axis of rotation of the drive wheel when the track assembly moves on the ground; the second given one of the guiding wheels is spaced apart from the first given one of the guiding wheels in a widthwise direction of the track assembly; the second given one of the guiding wheels is resilient to be elastically deformable when the track assembly moves on the ground; and the first given one of the guiding wheels and the second given one of the guiding wheels collectively occupy a majority of a span of the first given one of the guiding wheels and the second given one of the guiding wheels in the widthwise direction of the track assembly. 
     
     
         66 . The track assembly of  claim 48 , wherein a radial extent of the given one of the guiding wheels corresponding to at least 20% of an outer radius of the given one of the guiding wheels is elastically deformable when the track assembly moves on the ground. 
     
     
         67 . The track assembly of  claim 48 , wherein the track-engaging arrangement comprises a frame supporting the guiding wheels and mounted about the axis of rotation of the drive wheel. 
     
     
         68 . The track assembly of  claim 48 , wherein the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the track-engaging arrangement comprises a frame supporting the guiding wheels and having a pivot point located between the leading idler wheel and the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         69 . The track assembly of  claim 68 , wherein the pivot point of the frame corresponds to the axis of rotation of the drive wheel. 
     
     
         70 . The track assembly of  claim 48 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and a distance between the axis of rotation of the drive wheel and an axis of rotation of the leading idler wheel in the longitudinal direction of the track assembly is different from a distance between the axis of rotation of the drive wheel and an axis of rotation of the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         71 . The track assembly of  claim 48 , wherein the inner side of the track comprises a plurality of drive projections and the drive wheel comprises a sprocket for engaging the drive projections. 
     
     
         72 . The track assembly of  claim 48 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the bottom run of the track rises towards the leading idler wheel. 
     
     
         73 . The track assembly of  claim 48 , wherein the track assembly is steerable by a steering mechanism of the vehicle to change an orientation of the track assembly relative to the vehicle. 
     
     
         74 . A set of four track assemblies for traction of a vehicle, wherein each of at least two of the four track assemblies is as claimed in  claim 48 . 
     
     
         75 . A vehicle comprising the track assembly of  claim 48 . 
     
     
         76 . The vehicle of  claim 75 , wherein the vehicle is an all-terrain vehicle (ATV). 
     
     
         77 . A track assembly for traction of a vehicle, the track assembly comprising:
 a) a track comprising a ground-engaging outer side for engaging the ground and an inner side opposite to the ground-engaging outer side; and   b) a track-engaging arrangement for driving and guiding the track around the track-engaging arrangement, a bottom run of the track extending under the track-engaging arrangement, the track-engaging arrangement comprising:
 i. a drive wheel for driving the track; and 
 ii. a plurality of guiding wheels contacting the bottom run of the track, the plurality of guiding wheels including a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; 
 wherein: a distance between an axis of rotation of the drive wheel and an axis of rotation of the leading idler wheel in the longitudinal direction of the track assembly is different from a distance between the axis of rotation of the drive wheel and an axis of rotation of the trailing idler wheel in the longitudinal direction of the track assembly; 
   and a given one of the guiding wheels is resilient to be elastically deformable when the track assembly moves on the ground.   
     
     
         78 . A track assembly for traction of a vehicle, the track assembly being steerable by a steering mechanism of the vehicle to change an orientation of the track assembly relative to the vehicle, the track assembly comprising:
 a) a track comprising a ground-engaging outer side for engaging the ground and an inner side opposite to the ground-engaging outer side; and   b) a track-engaging arrangement for driving and guiding the track around the track-engaging arrangement, a bottom run of the track extending under the track-engaging arrangement, the track-engaging arrangement comprising:
 i. a drive wheel for driving the track; and 
 ii. a plurality of guiding wheels contacting the bottom run of the track; 
 wherein a given one of the guiding wheels is resilient to be elastically deformable when the track assembly moves on the ground. 
   
     
     
         79 . A track assembly for traction of a vehicle, the track assembly comprising:
 a) a track comprising a ground-engaging outer side for engaging the ground and an inner side opposite to the ground-engaging outer side; and   b) a track-engaging arrangement for driving and guiding the track around the track-engaging arrangement, a bottom run of the track extending under the track-engaging arrangement, the track-engaging arrangement comprising:
 i. a drive wheel for driving the track; and 
 ii. a plurality of guiding wheels contacting the bottom run of the track; 
 wherein a given one of the guiding wheels comprises foam. 
   
     
     
         80 . The track assembly of  claim 79 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel. 
     
     
         81 . The track assembly of  claim 80 , wherein the given one of the leading idler wheel and the trailing idler wheel is the leading idler wheel. 
     
     
         82 . The track assembly of  claim 81 , wherein the trailing idler wheel comprises foam. 
     
     
         83 . The track assembly of  claim 79 , wherein: an axis of rotation of the given one of the guiding wheels is movable relative to an axis of rotation of the drive wheel when the track assembly moves on the ground. 
     
     
         84 . The track assembly of  claim 79 , wherein the plurality of guiding wheels includes: a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and a plurality of support wheels disposed between the leading idler wheel and the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         85 . The track assembly of  claim 84 , wherein the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel. 
     
     
         86 . The track assembly of  claim 79 , wherein the foam is closed-cell foam. 
     
     
         87 . The track assembly of  claim 86 , wherein the closed-cell foam is closed-cell polyurethane foam. 
     
     
         88 . The track assembly of  claim 79 , wherein the foam forms at least part of a periphery of the given one of the guiding wheels. 
     
     
         89 . The track assembly of  claim 84 , wherein: the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel; and an outer diameter of the given one of the leading idler wheel and the trailing idler wheel is greater than an outer diameter of a given one of the support wheels. 
     
     
         90 . The track assembly of  claim 84 , wherein: the given one of the guiding wheels is a given one of the leading idler wheel and the trailing idler wheel; and the given one of the leading idler wheel and the trailing idler wheel is wider than a given one of the support wheels in a widthwise direction of the track assembly. 
     
     
         91 . The track assembly of  claim 89 , wherein the given one of the leading idler wheel and the trailing idler wheel is wider than the given one of the support wheels in a widthwise direction of the track assembly. 
     
     
         92 . The track assembly of  claim 80 , wherein: the track-engaging arrangement comprises a frame supporting the leading idler wheel and the trailing idler wheel; and a width of the given one of the leading idler wheel and the trailing idler wheel in a widthwise direction of the track assembly occupies at least a majority of a distance between a lateral surface of the given one of the leading idler wheel and the trailing idler wheel and a center of the frame in the widthwise direction of the track assembly. 
     
     
         93 . The track assembly of  claim 79 , wherein: the inner side of the track comprises a plurality of wheel-contacting projections for contacting at least one of the drive wheel and the guiding wheels; and a width of the given one of the guiding wheels in a widthwise direction of the track assembly is greater than a dimension of a given one of the wheel-contacting projections in the widthwise direction of the track assembly. 
     
     
         94 . The track assembly of  claim 93 , wherein the plurality of wheel-contacting projections comprises a plurality of drive projections and the drive wheel comprises a sprocket for engaging the drive projections. 
     
     
         95 . The track assembly of  claim 79 , wherein a radial extent of the given one of the guiding wheels corresponding to at least 20% of an outer radius of the given one of the guiding wheels is elastically deformable when the track assembly moves on the ground. 
     
     
         96 . The track assembly of  claim 79 , wherein the track-engaging arrangement comprises a frame supporting the guiding wheels and mounted about an axis of rotation of the drive wheel. 
     
     
         97 . The track assembly of  claim 79 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the track-engaging arrangement comprises a frame supporting the guiding wheels and having a pivot point located between the leading idler wheel and the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         98 . The track assembly of  claim 97 , wherein the pivot point of the frame corresponds to an axis of rotation of the drive wheel. 
     
     
         99 . The track assembly of  claim 79 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and a distance between an axis of rotation of the drive wheel and an axis of rotation of the leading idler wheel in the longitudinal direction of the track assembly is different from a distance between the axis of rotation of the drive wheel and an axis of rotation of the trailing idler wheel in the longitudinal direction of the track assembly. 
     
     
         100 . The track assembly of  claim 79 , wherein the inner side of the track comprises a plurality of drive projections and the drive wheel comprises a sprocket for engaging the drive projections. 
     
     
         101 . The track assembly of  claim 79 , wherein: the plurality of guiding wheels includes a leading idler wheel and a trailing idler wheel spaced apart in a longitudinal direction of the track assembly; and the bottom run of the track rises towards the leading idler wheel. 
     
     
         102 . The track assembly of  claim 79 , wherein the track assembly is steerable by a steering mechanism of the vehicle to change an orientation of the track assembly relative to the vehicle. 
     
     
         103 . A set of four track assemblies for traction of a vehicle, wherein each of at least two of the four track assemblies is as claimed in  claim 79 . 
     
     
         104 . A vehicle comprising the track assembly of  claim 79 . 
     
     
         105 . The vehicle of  claim 104 , wherein the vehicle is an all-terrain vehicle (ATV).