Rear track assembly for a vehicle

Patent metadata

Field	Value
Publication number	US-2018229784-A1
Application number	US-201815898006-A
Country	US
Kind code	A1
Filing date	Feb 15, 2018
Priority date	Feb 15, 2017
Publication date	Aug 16, 2018
Grant date	—

Abstract

A track assembly to be mounted on a vehicle. The track assembly has a frame, a drive wheel, and front and rear idler wheel assemblies rotationally mounted to the frame. A track is mounted around the front and rear idler wheel assemblies, and the drive wheel. The track has traction lugs distributed along an outer surface thereof. The frame has an effective frame length equal to a horizontal distance between a foremost point on the outer surface of the track and the rear idler wheel assembly axis. The effective frame length is between 48 and 60 inches. The frame has an effective frame height equal to a vertical distance between the drive wheel axis and a point on the outer surface of the track, the point being positioned directly below the drive wheel axis. The effective frame height is between 17 and 20 inches.

First claim

1 . A track assembly to be mounted to a rotatable rear axle of a vehicle, the rotatable rear axle being structured for mechanical attachment of a wheel thereto, comprising:
a frame having a front, a rear, a bottom, a left side, and a right side; a drive wheel rotationally mounted to the frame for rotation about a drive wheel axis positioned in a vertical drive wheel plane, the drive wheel having a peripheral surface, the drive wheel being structured to be attached to the axle of the vehicle when the wheel is removed; a front idler wheel assembly mounted at the front of the frame for rotation about a front idler wheel assembly axis parallel to the drive wheel axis, the front idler wheel assembly having a peripheral surface; a rear idler wheel assembly mounted at the rear of the frame for rotation about a rear idler wheel assembly axis parallel to the drive wheel axis, the rear idler wheel assembly having a peripheral surface; and a track having an inner surface facing the drive wheel, and an outer surface opposite the inner surface, the outer surface having a plurality of traction lugs distributed along the outer surface; the drive wheel, the front idler wheel assembly and the rear idler wheel assembly being positioned relative to the frame to support the track around the drive wheel peripheral surface, the front idler wheel assembly peripheral surface, and the rear idler wheel assembly peripheral surface, the track being in driving engagement with the drive wheel, at least one of the front idler wheel assembly and the rear idler wheel assembly being selectively movable between a plurality of longitudinally-distributed tension positions to tension the track, the frame having an effective frame length equal to a horizontal distance between a foremost point on the outer surface of the track and the rear idler wheel assembly axis, the effective frame length being between 48 inches and 60 inches, and the frame having an effective frame height equal to a vertical distance between the drive wheel axis and a point on the outer surface of the track, the point being positioned directly below the drive wheel axis, the effective frame height being between 17 inches and 20 inches.

2 . The track assembly of claim 1 , wherein the frame includes:
a longitudinally-extending left slide rail positioned at the bottom of the frame, the left slide rail having a bottom surface, a front end, a rear end and a length; and a longitudinally-extending right slide rail positioned at the bottom of the frame, the right slide rail having a bottom surface, a front end, a rear end, and a length.

3 . The track assembly of claim 2 , wherein the drive wheel, wheels of the front idler wheel assembly and wheels of the rear idler wheel assembly are the sole wheels of the track assembly contacting the track.

4 . The track assembly of claim 3 , further comprising a plurality of mid-rollers, each mid-roller of the plurality of mid-rollers being connected to at least one of the left slide rail and the right slide rail to rotate about a mid-roller axis that defines a mid-roller plane with the drive wheel axis, the mid-roller plane defining an angle with the vertical drive wheel plane that has a magnitude of not more than 20 degrees.

5 . The track assembly of claim 4 , wherein the plurality of mid-rollers is positioned relative to the left slide rail and the right slide rail such that each mid-roller in the plurality of mid-rollers extends downward past the bottom surface of each of the left slide rail and the right slide rail by 2/25.4 inches to 6/25.4 inches.

6 . The track assembly of claim 1 , wherein each traction lug of the plurality of traction lugs has a lug length of approximately one-third of a width of the track.

7 . The track assembly of claim 1 , wherein each traction lug of the plurality of traction lugs has a lug length of approximately one-quarter of a width of the track.

8 . The track assembly of claim 1 , wherein the plurality of traction lugs is arranged in a 2-1 repeating pattern.

9 . The track assembly of claim 1 , wherein the plurality of traction lugs is arranged in a 2-2 repeating pattern.

10 . The track assembly of claim 1 , wherein at least some traction lugs in the plurality of traction lugs are longitudinally spaced from each other by 5 to 8 inches.

11 . The track assembly of claim 1 , wherein the rear idler wheel assembly has four idler wheels.

12 . The track assembly of claim 1 , wherein the track assembly further comprises a dynamic traction device having one end connected to the frame and another end connected to the vehicle when the track assembly is in use.

13 . The track assembly of claim 1 , wherein the track has a track perimeter of 135 inches to 180 inches.

14 . The track assembly of claim 1 , as they depend directly or indirectly from claim 2 , wherein:
the front idler wheel assembly has a front idler wheel assembly radius, the bottom surface of each of the left slide rail and the right slide rail has an upward curvature having an upward radius of curvature, the upward curvatures of the left slide rail and the right slide rail are sized such that the track bends around the front idler wheel assembly and the upward curvatures of the left and right slide rails about an effective wheel radius, and the effective wheel radius is greater than each of the front idler wheel assembly radius and the upward radius of curvature.

15 . The track assembly of claim 2 , wherein the drive wheel, the front idler wheel assembly, the rear idler wheel assembly, the bottom surfaces of the left and right slide rails, and the track are sized and positioned relative to each other such that when:
the track assembly is mounted to the vehicle, the vehicle is traveling forward on flat level surface terrain covered with snow, and the track is being driven by the drive wheel about a path around the drive wheel, the front idler wheel assembly, the left and right slide rails, and the rear idler wheel assembly, each traction lug in the plurality of the traction lugs enters the snow substantially perpendicular to the flat level surface terrain and remains perpendicular to the flat level surface terrain as the track travels about its path at least until that traction lug begins to exit the snow.

16 . The track assembly of claim 1 , wherein each traction lug of the plurality of traction lugs has a lug height that is in range of 1.37 inches to 2.5 inches.

17 . A vehicle having a rotatable rear axle that is structured for mechanical attachment of a wheel thereto, comprising the track assembly of claim 1 , the track assembly being attached to the rear axle to support the vehicle on terrain.

18 . The vehicle of claim 17 , wherein the vehicle is one of: an All-Terrain Vehicle, a Side-by-Side Vehicle, and a wheelchair.

19 . The vehicle of claim 17 , wherein the vehicle has a ground clearance, and a ratio between the effective frame length of the frame of the track assembly and the ground clearance is between 2.6 and 3.5.

20 . The vehicle of claim 19 , further comprising a rotatable front axle and a front track assembly being attached to the front axle, the front track assembly having an effective frame height that is within 1 inch of the effective frame height of the track assembly that is attached to the rear axle.

Assignees

• Soucy Int Inc

Inventors

• Marchildon Louis-Frederic
• L'Herault Patrick

Classifications

• B62D55/084 Primary

  Endless-track units or carriages mounted separably, adjustably or extensibly on vehicles, e.g. portable track units (B62D55/07 takes precedence) · CPC title

• B62D55/10

  Bogies; Frames (track-tensioning means B62D55/30) · CPC title

• B62D55/065

  Multi-track vehicles, i.e. more than two tracks {(soil-shifting machines E02F; mining machines E21C)} · CPC title

• A61G5/066

  with endless belts · CPC title

• B62D55/125

  Final drives · CPC title