CA2865693C

CA2865693C - Drive track for snowmobile or tracked vehicle

Info

Publication number: CA2865693C
Application number: CA2865693A
Authority: CA
Inventors: Jules Dandurand; Denis Courtemanche
Original assignee: Camso Inc
Current assignee: Camso Inc
Priority date: 2005-06-02
Filing date: 2006-05-11
Publication date: 2017-07-11
Anticipated expiration: 2026-05-11
Also published as: CA2865698C; CA2546314C; CA2865693A1; CA2865698A1; CA2546314A1

Abstract

A track formed of a molded rubber base sandwiching a cord layer, followed by a cross bar and a single layer of ply fabric extending longitudinally of the track.

Description

TITLE OF THE INVENTION
[0001] Drive track for snowmobile or tracked vehicle FIELD OF THE INVENTION

[0002] The present invention pertains to a drive track and, more particularly, to a track for snowmobiles or other tracked vehicles, having an improved construction to decrease horse power, increase top speed and improve durability of the track when the latter is driven at high rotational speeds.
BACKGROUND OF THE INVENTION

[0003] Endless drive tracks for propelling, for example, a snowmobile over snow, ice or other similar ground structure, are known in the art. The mounting of this track to a snowmobile and the mounting of such track on an all-terrain vehicle are well known. The track has a ground engaging outer side and an inner side that receives and supports, on the lower run thereof, a suspension which may consist of a wheel assembly or a slide rail assembly, both of which are also well known in the art.

[0004] Conventionally, the track rotates by means of a motor driven sprocket unit at the forward end of the vehicle and idle drive wheels are mounted at the aft end of the vehicle to support the rear end of the track.
Sprockets engage a series of lugs integrally formed with the inner surface of the track.

[0005] With reference to Figure 1, the endless body is generally formed of a molded rubber base having, embedded therein, a first layer of reinforcing fabric 38 extending longitudinally of the track, a series of laterally spaced cord strands 40 which extend between the first layer of fabric and beneath a rod 32, and a second ply 36 of fabric disposed above the rod 32. Such arrangement has been shown to allow good track performance and longevity. It is generally believed that an increased amount of fabric contributes these performances. In areas of the track where there is no rod 32, it is about at mid-thickness of the track where the fiber of the rubber is the strongest, this line of zero stress in cross section of the track separating the region of compressive stress from that of tensile stress being known as the neutral fiber.

[0006] In spite of efforts in this field, there is still a need for a lighter, cost effective track.
SUMMARY OF THE INVENTION

[0007]
More specifically, there is provided a track for a tracked vehicle, comprising a molded rubber base sandwiching a cord layer, followed by a cross bar and a single layer of ply fabric extending longitudinally of the track.
[0007A] In accordance with an aspect of the invention, there is provided an endless snowmobile track for traction of a snowmobile. The endless snowmobile track comprises: a rubber-based body having an inner side for facing a driving wheel of the snowmobile and a ground-engaging outer side for engaging a ground surface on which the snowmobile travels; a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless snowmobile track; a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side, the endless snowmobile track being free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side; and a plurality of cross bars embedded within the rubber-based body, spaced apart from one another along the longitudinal direction of the endless snowmobile track, and extending transversally to the longitudinal direction of the endless snowmobile track.
[0007B] In accordance with another aspect of the invention, there is provided an endless all-terrain vehicle (ATV) track for traction of an ATV. The endless ATV
track comprises: a rubber-based body having: an inner side for facing a driving wheel of the ATV and a ground-engaging outer side for engaging a ground surface on which the ATV travels; a plurality of traction projections on the ground-engaging outer side, the traction projections engaging the ground surface when the ATV
travels on the ground surface; a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless ATV track; and a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side. The endless ATV track is free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.
[0007C] In accordance with another aspect of the invention, there is provided an endless snowmobile track for traction of a snowmobile. The endless snowmobile track comprises: a rubber-based body having an inner side for facing a driving wheel of the snowmobile and a ground-engaging outer side for engaging a ground surface on which the snowmobile travels; a plurality of traction projections on the ground-engaging outer side, the traction projections engaging the ground surface when the snowmobile travels on the ground surface; a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless snowmobile track; and a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side. The endless snowmobile track is free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

[0008] Other objects, advantages and features of the present invention will become more apparent upon reading of the following nonrestrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In the appended drawings:

[0010] Figure 1 is a cross section of a track as known in the art;

[0011] Figure 2 is a perspective view of a portion of a track according to an embodiment of the present invention;

[0012] Figure 3 is a cross-sectional view of the of Figure 2;

[0013] Figure 4 is a graph of power as a function of speed, used by a track according to the present invention, in a test without traction; and

[0014] Figure 5 is a graph of power as a function of speed, used by a track according to the present invention, in a test including traction.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0015] As shown in Figure 2, a track 10 according to an embodiment of the present invention comprises a ground engaging outer side 12 and an inner side (not seen in Figure 2).

[0016] As seen in the cross-section of Figure 3, the track 10 is formed of a molded rubber base 30 sandwiching a cord layer 32, followed by a cross bar 34 and a single layer of ply fabric 36 extending longitudinally of the track.

[0017] The cross bar 34 may consists of a rod as known in the art, made of composite material for example. It is located at spaced intervals along the longitudinal direction of the track beneath the profiles 14 projecting from the outer side 12 of the track.

[0018] The cord layer 32 comprises a dense strand arrangement formed of a twist arrangement of strands, comprising for example at least 18 strands per inch for a cord of 1.25 mm. The strands include high strength, light weight materials such as man made fibers, such as KevlarTM, nylon, and polyester fabric for example

[0019] The cord layer 32 extends on the rubber base 30 and passes beneath the rod 34.

[0020] The cord layer 32 may be discontinued at locations of the track where the idler wheels pass.

[0021] The ply of fabric 36 includes woven man-made fibers such as nylon for example.

[0022] As shown in Figures 4 and 5, the present track is found to necessitate equal or less power, which goes against the current belief in the industry that the greater the amount of fabric in the track composition, the better the performances.

[0023] People in the art will appreciate that the present invention provides, in contrast to a track standardly made in the art and including an arrangement of rubber, a first ply fabric, cord, rod, second ply fabric and rubber, a track comprising a single layer of ply fabric, yielding a =track of reduced thickness, weight and cost, while maintaining target performances thereof in terms of power and longevity. In particular, the present composition is shown to decrease horse power, increase top speed and improve durability of the track when the latter is driven at high rotational speeds. It has also been found to optimize the so-called neutral fiber bringing it closer to the outer side of the track.

[0024] The present track may be used for a range of tracked vehicles.

[0025] 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.

Claims

CLAIMS:

1. An endless snowmobile track for traction of a snowmobile, the endless snowmobile track comprising:
a) a rubber-based body having: an inner side for facing a driving wheel of the snowmobile; and a ground-engaging outer side for engaging a ground surface on which the snowmobile travels;
b) a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless snowmobile track;
c) a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side, the endless snowmobile track being free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side; and d) a plurality of cross bars embedded within the rubber-based body, spaced apart from one another along the longitudinal direction of the endless snowmobile track, and extending transversally to the longitudinal direction of the endless snowmobile track.

2. An endless snowmobile track as claimed in claim 1, wherein the one of the inner side and the ground-engaging outer side is the ground-engaging outer side.

3. An endless snowmobile track as claimed in claim 1, wherein the one of the inner side and the ground-engaging outer side is the inner side.

4. An endless snowmobile track as claimed in any one of claims 1 to 3, wherein the reinforcing woven fabric layer is located within the rubber-based body such that a neutral area separating a region of compressive stress of the endless snowmobile track and a region of tensile stress of the endless snowmobile track is closer to the ground-engaging outer side than to the inner side in a thickness direction of the endless snowmobile track.

5. An endless snowmobile track as claimed in any one of claims 1 to 4, wherein the reinforcing woven fabric layer comprises woven man-made fibers.

6. An endless snowmobile track as claimed in any one of claims 1 to 5, wherein each cord includes a plurality of strands.

7. An endless snowmobile track as claimed in claim 6, wherein the strands of each cord are twisted.

8. An endless snowmobile track as claimed in any one of claims 6 and 7, wherein the strands of each cord are made of at least one of Kevlar.TM., nylon and polyester.

9. An endless snowmobile track as claimed in claim 1, wherein the reinforcing woven fabric layer is located between the cross bars and the ground-engaging outer side.

10. An endless snowmobile track as claimed in claim 1, wherein the one of the inner side and the ground-engaging outer side is the inner side, the cross bars being located between the cord layer and the ground-engaging outer side.

11. An endless snowmobile track as claimed in any one of claims 1 to 10, wherein the reinforcing woven fabric layer is located between the cord layer and the cross bars.

12. An endless snowmobile track as claimed in any one of claims 1 to 11, wherein each cross bar comprises composite material.

13. An endless snowmobile track as claimed in claim 5, wherein the woven man-made fibers are woven nylon fibers.

14. An endless snowmobile track as claimed in any one of claims 1 to 13, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in a thickness direction of the endless snowmobile track.

15. An endless snowmobile track as claimed in claim 14, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in the thickness direction of the endless snowmobile track by a distance greater than a thickness of the reinforcing woven fabric layer.

16. An endless snowmobile track as claimed in any one of claims 1 to 15, wherein, when operated at a given speed, the endless snowmobile track consumes less power than if the endless snowmobile track comprised an additional layer of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

17. An endless snowmobile track as claimed in claim 16, wherein the given speed is above 100 miles per hour.

18. A snowmobile comprising an endless snowmobile track as claimed in any one of claims 1 to 17.

19. An endless all-terrain vehicle (ATV) track for traction of an ATV, the endless ATV
track comprising:
a) a rubber-based body having: an inner side for facing a driving wheel of the ATV; and a ground-engaging outer side for engaging a ground surface on which the ATV travels;

b) a plurality of traction projections on the ground-engaging outer side, the traction projections engaging the ground surface when the ATV travels on the ground surface;
c) a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless ATV track; and d) a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side, the endless ATV track being free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

20. An endless ATV track as claimed in claim 19, wherein the one of the inner side and the ground-engaging outer side is the ground-engaging outer side.

21. An endless ATV track as claimed in claim 19, wherein the one of the inner side and the ground-engaging outer side is the inner side.

22. An endless ATV track as claimed in any one of claims 19 to 21, wherein the reinforcing woven fabric layer is located within the rubber-based body such that a neutral area separating a region of compressive stress of the endless ATV
track and a region of tensile stress of the endless ATV track is closer to the ground-engaging outer side than to the inner side in a thickness direction of the endless ATV track.

23. An endless ATV track as claimed in any one of claims 19 to 22, wherein the reinforcing woven fabric layer comprises woven man-made fibers.

24. An endless ATV track as claimed in any one of claims 19 to 23, wherein each cord includes a plurality of strands.

25. An endless ATV track as claimed in claim 24, wherein the strands of each cord are twisted.

26. An endless ATV track as claimed in any one of claims 24 and 25, wherein the strands of each cord are made of at least one of Kevlar.TM., nylon and polyester.

27. An endless ATV track as claimed in claim 19, comprising a plurality of cross bars embedded within the rubber-based body, spaced apart from one another along the longitudinal direction of the endless ATV track, and extending transversally to the longitudinal direction of the endless ATV track.

28. An endless ATV track as claimed in claim 27, wherein the reinforcing woven fabric layer is located between the cross bars and the ground-engaging outer side.

29. An endless ATV track as claimed in claim 27, wherein the one of the inner side and the ground-engaging outer side is the inner side, the cross bars being located between the cord layer and the ground-engaging outer side.

30. An endless ATV track as claimed in claim 27, wherein the reinforcing woven fabric layer is located between the cord layer and the cross bars.

31. An endless ATV track as claimed in any one of claims 27 to 30, wherein each cross bar comprises composite material.

32. An endless ATV track as claimed in claim 23, wherein the woven man-made fibers are woven nylon fibers.

33. An endless ATV track as claimed in any one of claims 19 to 32, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in a thickness direction of the endless ATV track.

34. An endless ATV track as claimed in claim 33, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in the thickness direction of the endless ATV track by a distance greater than a thickness of the reinforcing woven fabric layer.

35. An endless ATV track as claimed in any one of claims 19 to 34, wherein, when operated at a given speed, the endless ATV track consumes less power than if the endless ATV track comprised an additional layer of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

36. An endless ATV track as claimed in claim 35, wherein the given speed is above 100 miles per hour.

37. An endless ATV track as claimed in any one of claims 19 to 36, wherein individual ones of the traction projections are spaced apart from one another along the longitudinal direction of the endless ATV track.

38. An endless ATV track as claimed in claim 37, wherein individual ones of the traction projections are spaced apart from one another along a widthwise direction of the endless ATV track.

39. An endless ATV track as claimed in any one of claims 19 to 38, wherein a given one of the traction projections comprises a first part having a first height and a second part having a second height different from the first height, each of the first height and the second height being measured along a thickness direction of the endless ATV track.

40. An endless ATV track as claimed in any one of claims 19 to 39, wherein a given one of the traction projections comprises a first part having a first thickness and a second part having a second thickness different from the first thickness, each of the first thickness and the second thickness being measured along the longitudinal direction of the endless ATV track.

41. An ATV comprising an endless ATV track as claimed in any one of claims 19 to 40.

42. An endless snowmobile track for traction of a snowmobile, the endless snowmobile track comprising:
a) a rubber-based body having: an inner side for facing a driving wheel of the snowmobile; and a ground-engaging outer side for engaging a ground surface on which the snowmobile travels;
b) a plurality of traction projections on the ground-engaging outer side, the traction projections engaging the ground surface when the snowmobile travels on the ground surface;
c) a cord layer embedded within the rubber-based body and including a plurality of cords extending generally parallel to one another and in a longitudinal direction of the endless snowmobile track; and d) a reinforcing woven fabric layer embedded within the rubber-based body between the cord layer and one of the inner side and the ground-engaging outer side, the endless snowmobile track being free of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

43. An endless snowmobile track as claimed in claim 42, wherein the one of the inner side and the ground-engaging outer side is the ground-engaging outer side.

44. An endless snowmobile track as claimed in claim 42, wherein the one of the inner side and the ground-engaging outer side is the inner side.

45. An endless snowmobile track as claimed in any one of claims 42 to 44, wherein the reinforcing woven fabric layer is located within the rubber-based body such that a neutral area separating a region of compressive stress of the endless snowmobile track and a region of tensile stress of the endless snowmobile track is closer to the ground-engaging outer side than to the inner side in a thickness direction of the endless snowmobile track.

46. An endless snowmobile track as claimed in any one of claims 42 to 45, wherein the reinforcing woven fabric layer comprises woven man-made fibers.

47. An endless snowmobile track as claimed in any one of claims 42 to 46, wherein each cord includes a plurality of strands.

48. An endless snowmobile track as claimed in claim 47, wherein the strands of each cord are twisted.

49. An endless snowmobile track as claimed in any one of claims 47 and 48, wherein the strands of each cord are made of at least one of Kevlar .TM., nylon and polyester.

50. An endless snowmobile track as claimed in claim 42, comprising a plurality of cross bars embedded within the rubber-based body, spaced apart from one another along the longitudinal direction of the endless snowmobile track, and extending transversally to the longitudinal direction of the endless snowmobile track.

51. An endless snowmobile track as claimed in claim 50, wherein the reinforcing woven fabric layer is located between the cross bars and the ground-engaging outer side.

52. An endless snowmobile track as claimed in claim 50, wherein the one of the inner side and the ground-engaging outer side is the inner side, the cross bars being located between the cord layer and the ground-engaging outer side.

53. An endless snowmobile track as claimed in claim 50, wherein the reinforcing woven fabric layer is located between the cord layer and the cross bars.

54. An endless snowmobile track as claimed in any one of claims 50 to 53, wherein each cross bar comprises composite material.

55. An endless snowmobile track as claimed in any one of claims 42 to 54, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in a thickness direction of the endless snowmobile track.

56. An endless snowmobile track as claimed in claim 55, wherein the reinforcing woven fabric layer is spaced apart from the cord layer in the thickness direction of the endless snowmobile track by a distance greater than a thickness of the reinforcing woven fabric layer.

57. An endless snowmobile track as claimed in any one of claims 42 to 56, wherein, when operated at a given speed, the endless snowmobile track consumes less power than if the endless snowmobile track comprised an additional layer of reinforcing woven fabric between the cord layer and the other one of the inner side and the ground-engaging outer side.

58. An endless snowmobile track as claimed in claim 57, wherein the given speed is above 100 miles per hour.

59. An endless snowmobile track as claimed in any one of claims 42 to 58, wherein individual ones of the traction projections are spaced apart from one another along the longitudinal direction of the endless snowmobile track.

60. An endless snowmobile track as claimed in claim 59, wherein individual ones of the traction projections are spaced apart from one another along a widthwise direction of the endless snowmobile track.

61. An endless snowmobile track as claimed in any one of claims 42 to 60, wherein a given one of the traction projections comprises a first part having a first height and a second part having a second height different from the first height, each of the first height and the second height being measured along a thickness direction of the endless snowmobile track.

62. An endless snowmobile track as claimed in any one of claims 42 to 61, wherein a given one of the traction projections comprises a first part having a first thickness and a second part having a second thickness different from the first thickness, each of the first thickness and the second thickness being measured along the longitudinal direction of the endless snowmobile track.

63. A snowmobile comprising an endless snowmobile track as claimed in any one of claims 42 to 62.