Patent Application
20140008134
The present invention relates to ATV. More specifically, the present invention is concerned with a track assembly for an all-terrain vehicle.
As well known in the art, a track system may be installed on a wheeled ATV (or other wheeled recreational, industrial or agricultural vehicles), to provide an—at least partly—, temporarily, tracked ATV.
The resulting contact area between an endless belt of the tracked vehicle and the underlying ground surface, referred to as patch, is larger than the contact area, or patch, of a corresponding wheel of the vehicle when wheeled on the underlying ground surface, thereby increasing flotation of the vehicle, over smooth terrains such as snow for example.
A drawback is that, generally, this increased contact patch involves an increased area of friction, which needs to be opposed for steering. As a result, it is increasingly harder to rotate the patch around a pivot steering point and steering effort submitted to such a tracked vehicle is higher than to a corresponding wheeled vehicle, i.e. the ATV on its wheels for example.
Using endless belts having a curved transverse geometry allows reducing this problem by allowing an increased contact surface when needed, while maintaining a reduced contact surface on hard surfaces for example.
However, there is still a need in the art for a track assembly for an all-terrain vehicle.
More specifically, there is provided a vehicle having a main frame and supported on the ground by at least two track assemblies, each track assembly comprising a longitudinal endless belt tensioned around corner wheels and a sprocket wheel, and support wheels provided on a lower run of the longitudinal endless belt, on each side of a suspension arm of the main frame, wherein each track assembly comprises a laterally asymmetric structure comprising at least one of: 1) at least one of the support wheels, on one of: i) an inward side and ii) an outward side of the suspension arm, located at a lower position in relation to remaining support wheels; and iii) the belt laterally comprising regions of different profiles.
There is provided a drive system for a vehicle having a main frame supporting an engine and a body of the vehicle and steering device connected to the main frame, a longitudinal endless belt, disposed on the frame of the drive system and connected to the engine to propel the vehicle, being tensioned around corner wheels and a sprocket wheel, support wheels being provided on a lower run of the longitudinal endless belt, on each side of a suspension arm of the main frame, the drive system comprising a first lateral region and a second lateral region, the lateral regions being defined by at least one of: i) the endless belt laterally comprising regions of different profiles; and ii) at least one of the support wheels, on one of: i) an Inward side and ii) an outward side of the suspension arm, being located at a lower position in relation to remaining support wheels.
There is further provided a track assembly for a wheeled vehicle, comprising a longitudinal endless belt tensioned around corner wheels and a sprocket wheel, and support wheels provided on a lower run of the longitudinal endless belt, on each side of a suspension arm of the main frame, wherein each track assembly comprises a laterally asymmetric structure comprising at least one of: i) at least one of the support wheels, on one of: i) an inward side and ii) an outward side of the suspension arm, located at a lower position in relation to remaining support wheels; and ii) the belt laterally comprising regions of different profiles.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings.
In the appended drawings:
As illustrated in
The track assemblies may be operatively connected to the engine (not shown) to propel the vehicle 10.
As best seen in
In
Support wheels 34 are provided, on a lower run of the endless belt 22, on each side of a suspension arm 36 of the main frame 32 best seen in
The endless belt 22 of each track assembly is typically an endless reinforced rubber belt, having a ground engaging surface and an inner surface. The ground-engaging surface may be provided with traction lugs that engage the underlying ground surface, whereas the inner surface is provided with driving lugs that engage the wheels.
The endless belt 22 may have a generally convex transverse profile, from the outward peripheral edge to the inner peripheral edge thereof, to provide a limited contact surface with the underground when the underground is hard, as known in the art (see
When replacing a tire of a vehicle by a track assembly without modification of the geometry of the vehicle, the contact area, now between the endless belt and the underground surface, is generally shifted outward relative to the contact patch previously between the tire and the underground surface. It is found that by lowering an inner support wheel, the contact patch may be repositioned.
In a first embodiment of the present invention, as illustrated in
Thus, as illustrated in
Providing at least one support wheel lower than the remaining support wheels, on the inside of the main suspension arm, allows the contact patch provided by this at least one lower support wheel to be positioned at the location it used to be when the vehicle, conceived for tires, was on tires.
As known in the art, support wheels 34 may further be arranged in tandem in order to alleviate the load on the contacts points created, as tandem 38 shown in
The frame 44 of the tandem 38 of these inside support wheels 34i, which are thus in the contact patch, being mounted on the pivot 42 (
In such an arrangement, by providing that at least one lower support wheel is mounted on a secondary frame 44 pivotally connected to the main suspension arm so that the motion of the secondary frame is relatively independent from the rest of the track assembly, the generated contact patch moves as requested by the movement of the vehicle, for instance when the track pivots around a vertical axis for the vehicle being able to turn.
As shown in
In a second embodiment illustrated for example in
Therefore, the contact patch of a track system may, be shifted laterally in relation to the suspension arm 36, inwards (or outwards), by providing a asymmetric track assembly, either by lowering at least one inside (outside) support wheel relative to the remaining support wheels, or by using a belt that comprises, transversally, at least one first profile on the outer side thereof lower (higher) than a second profile on an inner side thereof.
As people in the art will appreciate, an asymmetric track according to the present invention may combine at least one inside support wheel lowered relative to the remaining support wheels and a varying-profile belt, as described hereinabove.
Therefore, the present invention provides track assemblies and a method that allow bringing the contact patch towards the inside of the suspension arm 36, thereby repositioning the normal tire contact patch, i.e. the contact patch of the vehicle when on wheels. As a result, the steering effort of the track system is reduced to a minimum in a range of conditions, including snow, dirt, asphalt, rocks, etc, for example.
Therefore, according to an aspect of the present invention, there is provided a vehicle comprising at least two asymmetric track assemblies replacing wheels of a wheeled vehicle.
A suspension as described herein may be applied to a range of wheeled vehicles, such as for example recreational vehicles, ATV, light industrial vehicles, industrial vehicles, agricultural vehicles and military vehicles.
The present invention allows reducing the steering effort in such vehicles, which geometry of the suspension Is specifically designed for wheels, to a minimum in all conditions, snow, dirt, asphalt, rocks, etc.
Although the present invention has been described hereinabove by way of embodiments thereof, it may be modified, without departing from the nature and teachings of the subject invention as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2606039 | Oct 2007 | CA | national |
This application is a continuation, and claims benefit under 35 U.S.C. §120, of U.S. patent application Ser. No. 13/711,663 filed on Dec. 12, 2012, which is a continuation, and claims benefit under 35 U.S.C. §120, of U.S. patent application Ser. No. 12/684,698 filed on Jan. 8, 2010, now U.S. Pat. No. 8,347,991, which is a continuation, and claims benefit under 35 U.S.C. §120, of U.S. patent application Ser. No. 12/028,177 filed on Feb. 8, 2008, now abandoned, which claims priority on Canadian application no. 2,606,039, filed on Oct. 3, 2007. All documents identified above are incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13711663 | Dec 2012 | US |
| Child | 13928759 | US | |
| Parent | 12684698 | Jan 2010 | US |
| Child | 13711663 | US | |
| Parent | 12028177 | Feb 2008 | US |
| Child | 12684698 | US |
