Track system for attachment to a vehicle

Patent metadata

Field	Value
Publication number	US-10252757-B2
Application number	US-201715485699-A
Country	US
Kind code	B2
Filing date	Apr 12, 2017
Priority date	Apr 12, 2016
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A track system for a vehicle having a rear swing arm that is movable between a compressed suspension position and an extended suspension position. The track system has a frame and a dynamic traction device. The frame is pivotably attachable to the swing arm. The dynamic traction device has at least two elongate portions, one of which is movable relative to the other between a retracted position and an extended position and biased toward the retracted position. In use, the elongate portions interconnect the vehicle and the frame. When the vehicle is lifted off terrain, during at least a part of a movement of the swing arm from the compressed suspension position toward the extended suspension position, the dynamic traction device applies a torque to the frame and thereby changes a longitudinal angular position of the frame counter-clockwise relative to a left side of the vehicle.

First claim

The invention claimed is:

1. A track system for attachment to a vehicle including:
I) a vehicle chassis having a front portion, a rear portion, a left side, and a right side;
II) a rear suspension having a swing arm attached to the rear portion of the vehicle chassis, the swing arm being moveable between a compressed-suspension position and an extended-suspension position;
III) an engine supported by the vehicle chassis for providing motive power to propel the vehicle;
IV) a rear axle being in driven connection with the engine;
the track system comprising:
a) a track system frame being pivotably attachable to the swing arm about the rear axle, the track system frame having an upper frame portion and a ground-facing frame assembly, the ground-facing frame assembly having a leading idler wheel assembly and a trailing idler wheel assembly attached thereto, the ground-facing frame assembly having a longitudinal angular position relative to the vehicle chassis when the track system frame is pivotably attached to the swing arm;
b) a drive sprocket being in driven connection with the rear axle when the track system frame is pivotably attached to the swing arm;
c) an endless track mounted around the drive sprocket, the leading idler wheel assembly, and the trailing idler wheel assembly, the endless track being in driven connection with the drive sprocket; and
d) a dynamic traction device having:
i) a first elongate portion having a first distal end, and
ii) a second elongate portion having a second distal end opposed to the first distal end, the second elongate portion being movable relative to the first elongate portion between a retracted position and an extended position, the second elongate portion being biased toward the retracted position,
iii) the first and second distal ends being closer together in the retracted position than in the extended position, and
iv) when
A) the track system frame is pivotably attached to the swing arm,
B) the drive sprocket is in driven connection with the rear axle,
C) the first distal end is pivotably attached to the vehicle chassis at a first attachment point, and
D) the second distal end is pivotably attached to the track system frame at a second attachment point,

the first attachment point and the second attachment point are located with respect to the vehicle chassis and the track system frame such that when the vehicle is lifted off terrain, during at least a part of a movement of the swing arm from the compressed-suspension position toward the extended-suspension position, the dynamic traction device applies a torque to the track system frame about the rear axle and thereby changes the longitudinal angular position of the ground-facing frame assembly counter-clockwise relative to the left side of the vehicle chassis.

2. The track system of claim 1 , wherein when the vehicle is lifted off terrain, during at least a part of a movement of the swing arm from the extended-suspension position toward the compressed-suspension position, the dynamic traction device applies a torque to the track system frame about the rear axle and thereby changes the longitudinal angular position of the ground-facing frame assembly clockwise relative to the left side of the vehicle chassis.

3. The track system of claim 2 , wherein when the vehicle is lifted off terrain, during at least a part of a movement of the swing arm from the extended-suspension position toward the compressed-suspension position, the dynamic traction device applies a torque to the track system frame about the rear axle and thereby changes the longitudinal angular position of the ground-facing frame assembly clockwise, relative to the left side of the vehicle chassis, by one to five degrees.

4. The track system of claim 1 , wherein
i) when the vehicle is stationary on flat horizontal terrain, the swing arm is in a neutral position that is between the compressed-suspension position and an extended-suspension position; and
ii) when a downward force is applied to the vehicle chassis such that the vehicle chassis moves downward and thereby moves the swing arm from the neutral position toward the toward the compressed-suspension position, during at least a part of this movement of the swing arm, the dynamic traction device applies a clockwise torque to the track system frame about the rear axle relative to the left side of the vehicle.

5. The track system of claim 1 , wherein when
i) the vehicle is stationary on flat horizontal terrain,
ii) the swing arm is a neutral position that is between the compressed-suspension position and an extended-suspension position; and
iii) an upward force is applied to the vehicle chassis such that the vehicle chassis moves upward and thereby moves the swing arm from the neutral position toward the extended-suspension position,
during at least a part of this movement of the swing arm, the dynamic traction device applies a counter-clockwise torque to the track system frame about the rear axle relative to the left side of the vehicle.

6. The track system of claim 1 , wherein while the vehicle is accelerating in a forward direction over uneven terrain, the dynamic traction device applies substantially a clockwise-only torque to the track system frame about the rear axle relative to the left side of the vehicle chassis.

7. The track system of claim 1 , wherein the trailing idler wheel assembly extends rearward of the rear axle by a distance of between 45 centimeters to 155 centimeters inclusive.

8. The track system of claim 1 , wherein:
i) when the vehicle is on flat horizontal terrain, the second elongate portion is in a neutral position; and
ii) the second elongate portion is biased from the neutral position to the retracted position.

9. The track system of claim 1 , wherein:
i) when the ground-facing frame assembly is in a range of three to ten degrees below a horizontal plane, the second elongate portion is in the retracted position; and
ii) when the ground-facing frame assembly is in a range of fifteen to thirty degrees above the horizontal plane, the dynamic traction device is in the extended position.

10. The track system of claim 1 , wherein:
i) when the ground-facing frame assembly is in a range of fifteen to thirty degrees below a horizontal plane, the second elongate portion is in the retracted position; and
ii) when the ground-facing frame assembly is in a range of fifteen to forty degrees above the horizontal plane, the dynamic traction device is in the extended position.

11. The track system of claim 1 , wherein:
i) the dynamic traction device includes a cylinder, the cylinder having a first end and a second end opposite the first end;
ii) the first elongate portion extends from the first end of the cylinder away from the second end of the cylinder;
iii) the second elongate portion is slidable into the cylinder; and
iv) the second elongate portion extends from the second end of the cylinder away from the first end of the cylinder.

12. The track system of claim 11 , wherein:
i) the dynamic traction device includes:
A) a resilient stopper disposed inside the cylinder proximate the first end of the cylinder, and
B) a spring disposed inside the cylinder proximate the second end of the cylinder;

ii) the second elongate portion includes a head portion sized to engage the spring in compression;
iii) the head portion is opposite the second distal end of the second elongate portion; and
iii) the head portion is disposed between the resilient stopper and the spring.

13. The track system of claim 12 , wherein:
i) the resilient stopper is a rubber stopper;
ii) the spring is a helical sprin

Assignees

• Soucy Int Inc

Inventors

• Marchildon Louis-Frederic
• L'Herault Patrick

Classifications

• B62D55/065

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

• 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

• B62D55/04

  with tracks and alternative ground wheels, e.g. changeable from endless track vehicle into wheeled vehicle and vice versa {(for multi-purpose tractors B62D49/0635)} · CPC title

• B62D55/12

  Arrangement, location, or adaptation of driving sprockets · CPC title

• B62D55/108

  with mechanical springs, e.g. torsion bars · CPC title