Track system with adjustable idler wheels and method of using the same

A track system for use as a wheel replacement on typically wheeled vehicle is disclosed. The track system comprises a drive wheel configured to be mounted to the vehicle, a support frame, front and rear idler wheels respectively pivotally mounted at the front and at the rear of the support frame, road wheels pivotally mounted along the support frame between the front and read idler wheels, and an endless track mounted about the wheels. The position of the front and/or rear idler wheels is adjustable in order to modify the overall shape of the perimeter of the track system generally defined by the endless track, thereby changing the riding behavior of the track system. A method to change the position of the adjustable idler wheels is also disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

There are no cross-related applications.

FIELD OF THE INVENTION

The present invention generally relates to track systems and traction assemblies for use as wheel replacement on typically wheeled vehicles, and more particularly relates to track systems and traction assemblies for use as wheel replacement on typically small vehicles such as, but not limited to, all-terrain vehicles (ATVs), utility-terrain vehicles (UTVs), and side-by-side vehicles (SSVs). The present invention also relates to track systems and traction assemblies for use as wheel replacement on large wheeled vehicles such as, but not limited to, industrial vehicles, construction vehicles, agricultural vehicles, and forestry vehicles.

BACKGROUND OF THE INVENTION

Several normally wheeled vehicles and particularly small wheeled vehicles (e.g. ATVs, UTVs, SSVs, etc.) often have their wheels replaced by track systems which use endless traction bands instead of tires for propulsion. Vehicles equipped with such track systems typically have improved floatation and better traction, particularly when they are operated over uneven and/or soft terrains.

However, track systems are often designed for particular operating conditions. For instance, some track systems are more particularly designed for operating over rough and irregular terrains. Such track systems are thus typically configured to be able to overcome obstacles such as fallen tree trunks, rocks, roots, etc.

Other track systems are more particularly designed for operating over soft terrains such as snowy, muddy or sandy terrains. Such track systems are therefore typically configured to increase floatation over such terrains.

Still other track systems are designed for average performances over both rough terrains and soft terrains.

However, unless a vehicle operator is satisfied with average performances, he typically needs at least two sets of track systems if he wishes to operate his vehicle over both rough and soft terrains. Understandably, having two sets of track systems is not only expensive, it is time consuming when the track systems need to be changed on the vehicle.

Hence, there is a need for an improved track system which mitigates at least some shortcomings of prior art track systems.

SUMMARY OF THE INVENTION

A track system in accordance with the principles of the present invention generally mitigates some of the shortcomings of prior track systems by having the front idler wheels and/or the rear idler wheels selectively adjustable such as to change the overall shape of the perimeter of the track system, defined by the endless track, in order to change the operating behavior of the track system.

Hence, a track system in accordance with the principles of the present invention generally comprises a drive wheel configured to be mounted to the vehicle, a support frame (or support frame assembly), front and rear idler wheels typically respectively pivotally mounted at the front and at the rear of the support frame, road (or support) wheels pivotally mounted along the support frame longitudinally between the idler wheels, and an endless track disposed about the drive wheel, the idler wheels and the road wheels.

The front idler wheels and/or the rear idler wheels are pivotally mounted to the support frame via an adjustable position adjustment mechanism mounted to the support frame. The adjustment mechanism allows the idler wheels to be in at least two different operating positions.

By changing the operating position of the idler wheels, the overall shape of the perimeter of the track system, generally defined by the endless track, can be changed, thereby changing the riding behavior of the track system.

In typical though non-limitative embodiments of a track system in accordance with the principles of the present invention, the adjustment mechanism allows at least a high operating position and a low operating position. When the front idler wheels are adjustable, the high operating position will raise the front portion of the overall shape of the perimeter of the track system, allowing it to generally more easily overcome obstacles present on rough terrains. For its part, the low operating position of the front idler wheels will lower the front portion of the overall shape of the perimeter of the track system, thereby increasing the floatation of the track system by generally increasing the size of its contact patch. When the rear idler wheels are adjustable, the high operating position will raise the rear portion of the overall shape of the perimeter of the track system, allowing it to generally more easily overcome obstacles present on rough terrains when the track system is operated in reverse. For its part, the low operating position of the rear idler wheels will lower the rear portion of the overall shape of the perimeter of the track system, thereby increasing the floatation of the track system by generally increasing the size of its contact patch.

Understandably, depending on the exact configurations of the track system and of the vehicle to which it is mounted, the different operating positions of the front and/or rear idler wheels may provide other and/or additional benefits.

When both the front and rear idler wheels are adjustable, the front and rear idler wheels can be independently adjusted to obtain particular riding performances. For instance, the front idler wheels could be in high operating position to allow the track system to more easily overcome obstacles, while the rear idler wheels could be in low operating position to improve floatation. Such adjustments could provide good overall performance over rough and soft terrains.

Similarly, when both the front and rear idler wheels are adjustable on both the front and rear track systems, the idler wheels can be adjusted differently on the front track system and on the rear track system to better suit the configurations of the front and rear track systems.

Understandably, by being able to selectively change the overall shape of the perimeter of the track system between different operating configurations, the track system in accordance with the principles of the present invention can be properly adjusted to be used in different operating conditions.

Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A novel track system with adjustable idler wheels, and a method of using the same, will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.

Referring first toFIGS. 1 and 5, an embodiment of a track system100in accordance with the principles of the present invention is shown. The track system100is configured to replace a wheel on a typically wheeled vehicle in order to generally improve the floatation and/or traction thereof. In the present embodiment, the track system100is configured to replace rear wheel on a typically small wheeled vehicle such as an ATV, a UTV, a SSV or any other similar recreational vehicle (see UTV600inFIG. 18).

The track system100comprises a drive wheel110configured to be mounted to the vehicle, typically to a wheel hub thereof, a support frame120, front idler wheels130and rear idler wheels140respectively pivotally mounted to the support frame120at the forward end122and at the rearward end124thereof, road (or support) wheels150pivotally mounted to the support frame120along its length, typically on both sides, and an endless track160disposed about the drive wheel110, the idler wheels130and140and the road wheels150, and configured to be drivingly engaged by the drive wheel110.

In the present embodiment, the drive wheel110is a sprocket wheel and drivingly engages the track160via drive lugs (not shown) disposed along the circumference of the inner surface162of the track160. The inner surface162can also comprises guide lugs (not shown) disposed along its circumference. For its part, the outer surface164of the track160comprises a plurality of traction lugs (not shown) configured to engage the ground surface over which the track system100is operated.

The track160is typically made of elastomeric material (e.g. rubber) and typically comprises longitudinal reinforcements (e.g. cables, cords, wire ropes) and lateral reinforcements (e.g. lateral rods, stiffeners).

In the present embodiment, the support frame120is pivotally mounted to the drive wheel110albeit it is not drivingly engaged by the drive wheel110. In other embodiments, the support frame120could be mounted directly to the vehicle.

As it will best be understood below, the rear idler wheels140are mounted to the support frame120such that they can be in at least two different operating positions. By allowing the rear idler wheels140to be in at least two different operating positions, the overall shape of the perimeter of the track system100, generally defined by the endless track160disposed about the wheels, can be changed to better suit the terrain over which the track system100is operated.

In that sense, referring now toFIGS. 2, 4, 6 and 8, in the present embodiment, the support frame120comprises a position adjustment mechanism170. The adjustment mechanism170pivotally supports the rear idler wheels140and allows the rear idler wheels140to be in at least two different operating positions.

The mechanism170generally comprises a clamping member (e.g. clamping ring)172integrated to the support frame120, and a rotatable support member174received into the clamping member172. The support member174pivotally supports the rear idler wheels140on a laterally extending shaft176. The shaft176defines an axis173which is not coaxial with the central axis175of the support member174. Hence, when the support member174is rotated within the clamping member172, the rear idler wheels140can be in at least two operating positions as best shown inFIGS. 4 and 8. Understandably, in the present embodiment, since the support member174can be rotated within the clamping member172, the rear idler wheels140could possibly be in an infinity of operating position if the endless track160is otherwise properly tensioned. Other embodiments of the adjustment mechanisms might however be limited to two operating positions (seeFIGS. 16A and 16B).

To properly hold the support member174within the clamping member172, the latter comprises bolt177and nut178for closing the clamping member172around the support member174and holding it by friction. The bolt177and nut178can also loosen the clamping member172to allow the support member174to rotate within it during adjustment.

Referring now toFIGS. 2-4, the support member174is depicted in a first operating position which, in the present embodiment, is a low operating position. As best shown inFIGS. 3 and 4, in such a position, the rear portion of the overall shape of the perimeter of the track system100is lowered, i.e. the rear idler wheels140are closer to the ground surface. Understandably, when the support member174and thus the idler wheels140are in such a low operating position, the track system100is particularly well suited for operation over soft terrains such as snowy, muddy or sandy terrain since the floatation of the track system100is increased. Indeed, as best shown inFIG. 3, by lowering the rear portion of the overall shape of the perimeter, the size of the contact patch166L of the track system100is increased, thereby spreading the weight of the vehicle over a larger area.

Now, inFIGS. 6-8, the support member174is depicted in a second operating position which, in the present embodiment, is a high operating position. As best shown inFIGS. 7 and 8, in such a position, the rear portion of the overall shape of the perimeter of the track system100is raised, i.e. the rear idler wheels140are farther from the ground surface, thereby raising the attack angle105of the track system100. Understandably, when the support member174and thus the idler wheels140are in such a high operating position, the track system100is particularly well suited for operation over rough terrains since the attack angle105is greater and the traction of the track system100is increased. Indeed, having a larger attack angle105allows the track system100to more easily overcome obstacles such as fallen tree trunks, rocks, and roots. In addition, as best shown inFIG. 7, by raising the rear portion of the overall shape of the perimeter, the size of the contact patch166H is decreased, thereby spreading the weight of the vehicle over a smaller area and increasing the traction of the track system100.

Understandably, the same principles would apply to an adjustment mechanism170supporting the front idler wheel130. In that sense, referring toFIG. 9, an overlaid comparison between the overall shape of the perimeters of a track system200, generally defined by the endless track260, when the adjustment mechanism170is in low operating position (solid lines) and when the adjustment mechanism170is in high operating position (dashed lines) is shown. The overlaid comparison clearly shows the change in the angle of attack and in the size of the contact patch when the position of both the front idler wheels230and the rear idler wheels240are changed.

FIGS. 10 to 13also show that by simply changing the operating position of the front idler wheels230, of the rear idler wheel240, of the both idler wheels, the overall shape of the perimeter of the track system200can be changed such as to adapt the track system200to different operating conditions. For instance, inFIG. 10, both the front idler wheels230and the rear idler wheels240are in low operating position. Such configuration could be advantageous over soft terrains since the contact patch is larger. InFIG. 11, the front idler wheels230are in high operating position while the rear idler wheels240are in low operating position. Such configuration provides an improved angle of attack while keeping a relatively large contact patch. InFIG. 12, the situation is reversed and the front idler wheels230are in low operating position while the rear idler wheels240are in high operating position. Such configuration provides an improved angle of attack when the track system200is operated in reverse while keeping a relatively large contact patch. Such a configuration can also reduce the turning radius of the vehicle by reducing the friction generated by the track system200. Finally, inFIG. 13, both the front idler wheels230and the rear idler wheels240are in high operating position. Such configuration could be advantageous over rough terrains since the front and rear angles of attack are greater, thereby allowing the track system200to more easily overcome obstacle, and the contact patch is smaller, thereby improving traction.

Similarly,FIGS. 14A and 14Brespectively illustrate the track system200with the rear idler wheels240in low operating position and with the rear idler wheels240in high operating position. Again, by changing the operating position of the rear idler wheels240, the operating configuration of the track system200can be changed to better suit terrain over which it is operated.

Referring now toFIGS. 15A and 15B, another embodiment of a track system300in accordance with the principles of the present invention is shown.

In track system300, the adjustment mechanism370differs from the adjustment mechanism170but still allows the rear idler wheels340to be in a first (or low) operating position as shown inFIG. 15A, and in a second (or high) operating position as shown inFIG. 15B.

In track system300, the adjustment mechanism370comprises an arcuate support member372which pivotally supports the rear idler wheels340. The support member372is pivotally mounted to the support frame320such as to be rotatable downwardly or upwardly. Adjustment mechanism370further comprises a locking mechanism374(e.g. a lock bolt) for locking the support member372in its downward or upward operating position.

Referring now toFIGS. 16A and 16B, another embodiment of a track system400in accordance with the principles of the present invention is shown.

In track system400, the adjustment mechanism470differs from adjustment mechanisms170and370but still allows the rear idler wheels440to be in a first (or low) operating position as shown inFIG. 16A, and in a second (or high) operating position as shown inFIG. 16B.

Adjustment mechanism470comprises an elongated support member472which is terminated by two different pivotal supports or shafts474and476for the rear idler wheels440. The support member472is slidingly mounted to the support frame420for tension adjustment. By mounting the rear idler wheels440to either the first pivotal support474or to the second pivotal support476, the rear idler wheels440can be in a first (or low) operating position as shown inFIG. 16A, and in a second (or high) operating position as shown inFIG. 16B.

Understandably, various adjustment mechanisms can be used to allow the front idler wheels and/or the rear idler wheels to be in different operating positions. In addition, though the adjustment mechanisms370and470typically allow only two different operating positions, other adjustment mechanisms such as adjustment mechanism170could allow more than two operating positions to allow the track system to be better suited to operate over various types of terrains.

Referring now toFIG. 17, an overlaid comparison between the overall shape of the perimeters of a front track system500when the adjustment mechanism170is in low operating position (solid lines) and when the adjustment mechanism170is in high operating position (dashed lines) is shown. The overlaid comparison clearly shows the change in the angle of attack and in the size of the contact patch when the position of both the front idler wheels530and the rear idler wheels540are changed.

Referring now toFIG. 18, the front track system500and the rear track system200are shown mounted to a vehicle600(e.g. a UTV) with overlaid comparisons of the overall shape of the perimeters when the idler wheels are in low operating position (solid lines) and in high operating position (dashed lines). Understandably, when the vehicle600is equipped with front and rear track systems have adjustable idler wheels, the idler wheels of both the front and the rear track systems can each be adjusted to better suit the terrain over which the vehicle is to be operated.

Understandably, by being able to selectively change the overall shape of the perimeter of a track system between different operating positions, a track system in accordance with the principles of the present invention can be properly adjusted to be used in different operating conditions while avoiding the need for an operator to have different sets of track systems.