DRIVE TRACK FOR SNOWMOBILE OR TRACKED VEHICLE

CHENILLE D'ENTRAINEMENT POUR MOTONEIGE OU VEHICULE CHENILLE

English 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.

French Abstract

Une chenille formée dune base en caoutchouc moulé prenant en sandwich une couche de câbles, suivie par une barre transversale et une seule couche de tissu en nappe sétendant longitudinalement dans la chenille.

Claims

6

CLAIMS:

1. An endless track for traction of a snowmobile or all-terrain vehicle (ATV),
the
endless track comprising:
a) a rubber-based body having:
- an inner side for facing a drive wheel of the snowmobile or ATV; and
- a ground-engaging outer side for engaging the ground on which the
snowmobile or ATV travels;
b) a plurality of rubber-based traction projections projecting outwardly from
the
ground-engaging outer side; and
c) a layer of reinforcing fabric embedded within the rubber-based body;
wherein the endless track is free of reinforcing fabric extending along the
endless track between the inner side and the layer of reinforcing fabric and
free
of reinforcing fabric extending along the endless track between the ground-
engaging outer side and the layer of reinforcing fabric.
2. The endless track claimed in claim 1, wherein the layer of reinforcing
fabric is
closer to the ground-engaging outer side than to the inner side in a thickness

direction of the endless track.
3. The endless track claimed in any one of claims 1 and 2, wherein the layer
of
reinforcing fabric is located within the rubber-based body such that a neutral

area separating a region of compressive stress of the endless track and a
region
of tensile stress of the endless track is closer to the ground-engaging outer
side
than to the inner side in a thickness direction of the endless track.
4. The endless track claimed in any one of claims 1 to 3, comprising a layer
of
cords embedded within the rubber-based body, the cords extending generally
parallel to one another and in a longitudinal direction of the endless track.


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5. The endless track claimed in claim 4, wherein the layer of reinforcing
fabric is
located between the ground-engaging outer side and the layer of cords.
6. The endless track claimed in claim 4, wherein the layer of reinforcing
fabric is
located between the inner side and the layer of cords.
7. The endless track claimed in any one of claims 4 to 6, wherein the layer of

reinforcing fabric is spaced apart from the layer of cords in a thickness
direction
of the endless track.
8. The endless track claimed in claim 7, wherein a spacing of the layer of
reinforcing fabric and the layer of cords in the thickness direction of the
endless
track is greater than a thickness of the layer of reinforcing fabric.
9. The endless track claimed in any one of claims 1 to 8, wherein each of the
cords
comprises a plurality of strands.
10. The endless track claimed in claim 1, comprising a plurality of cross bars

embedded within the rubber-based body, spaced apart from one another in a
longitudinal direction of the endless track, and extending transversally to
the
longitudinal direction of the endless track.
11. The endless track claimed in claim 10, wherein the layer of reinforcing
fabric is
located between the ground-engaging outer side and the cross bars.
12. The endless track claimed in claim 10, wherein the layer of reinforcing
fabric is
located between the inner side and the cross bars.
13. The endless track claimed in any one of claims 10 to 12, comprising a
layer of
cords embedded within the rubber-based body, the cords extending generally
parallel to one another and in the longitudinal direction of the endless
track.


8

14. The endless track claimed in claim 13, wherein the cross bars are located
between the layer of cords and the ground-engaging outer side.
15. The endless track claimed in any one of claims 13 and 14, wherein the
layer of
reinforcing fabric is located between the layer of cords and the cross bars.
16. The endless track claimed in any one of claims 10 to 15, wherein each of
the
cross bars comprises composite material.
17. The endless track claimed in any one of claims 1 to 16, wherein the layer
of
reinforcing fabric comprises reinforcing woven fabric.
18. The endless track claimed in claim 17, wherein the reinforcing woven
fabric
comprises woven manmade fibers.
19. The endless track claimed in any one of claims 1 to 18, wherein, when
operated
at a given speed, the endless track consumes less power than if the endless
track had an additional layer of reinforcing fabric embedded within the rubber-

based body and spaced apart from the layer of reinforcing fabric.
20. The endless track claimed in claim 19, wherein the given speed is above 60

miles per hour.
21. The endless track claimed in any one of claims 1 to 20, wherein respective
ones
of the rubber-based traction projections are spaced apart from one another in
a
longitudinal direction of the endless track.
22. The endless track claimed in claim 21, wherein certain ones of the rubber-
based
traction projections are spaced apart from one another in a widthwise
direction
of the endless track.


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23. The endless track claimed in any one of claims 1 to 22, wherein a
particular one
of the rubber-based traction projections comprises a first part having a first

height and a second part having a second height different from the first
height.
24. A snowmobile or ATV comprising the endless track claimed in any one of
claims
1 to 23.
25. An endless track for traction of a snowmobile or all-terrain vehicle
(ATV), the
endless track comprising:
a) a rubber-based body having:
- an inner side for facing a drive wheel of the snowmobile or ATV; and
- a ground-engaging outer side for engaging the ground on which the
snowmobile or ATV travels;
b) a plurality of rubber-based traction projections projecting outwardly from
the
ground-engaging outer side; and
c) a layer of reinforcing fabric embedded within the rubber-based body;
wherein the endless track does not comprise two layers of reinforcing fabric
embedded within the rubber-based body and spaced apart from one another.
26. An endless track for traction of a snowmobile or all-terrain vehicle
(ATV), the
endless track comprising:
a) a rubber-based body having:
- an inner side for facing a drive wheel of the snowmobile or ATV; and
- a ground-engaging outer side for engaging the ground on which the
snowmobile or ATV travels;
b) a plurality of rubber-based traction projections projecting outwardly from
the
ground-engaging outer side; and
c) a layer of reinforcing fabric embedded within the rubber-based body;
wherein, when operated at a given speed, the endless track consumes less
power than if the endless track had an additional layer of reinforcing fabric


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embedded within the rubber-based body and spaced apart from the layer of
reinforcing fabric.
27. A track for traction of a vehicle, the track being rubber-based and
comprising:
- an inner side for facing a drive wheel to impart motion to the track;
- a ground-engaging outer side for engaging the ground on which the vehicle

travels, the ground-engaging outer side comprising a plurality of traction
projections distributed in a longitudinal direction of the track; and
- a layer of reinforcing fabric embedded between the inner side and the
ground-
engaging outer side;
wherein a segment of the track is free of reinforcing fabric between the inner

side and the layer of reinforcing fabric and between the ground-engaging outer

side and the layer of reinforcing fabric.
28. The track claimed in claim 27, wherein the layer of reinforcing fabric is
closer to
a given one of the inner side and the ground-engaging outer side than to the
other one of the inner side and the ground-engaging outer side in a thickness
direction of the track.
29. The track claimed in claim 27, wherein the layer of reinforcing fabric is
located
such that a neutral area separating a region of compressive stress of the
track
and a region of tensile stress of the track is closer to a given one of the
inner
side and the ground-engaging outer side than to the other one of the inner
side
and the ground-engaging outer side in a thickness direction of the track.
30. The track claimed in claim 27, wherein the layer of reinforcing fabric is
closer to
the ground-engaging outer side than to the inner side in a thickness direction
of
the track.
31. The track claimed in claim 27, wherein the layer of reinforcing fabric is
located
such that a neutral area separating a region of compressive stress of the
track


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and a region of tensile stress of the track is closer to the ground-engaging
outer
side than to the inner side in a thickness direction of the track.
32. The track claimed in any one of claims 27 to 31, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.
33. The track claimed in claim 32, wherein the layer of reinforcing fabric is
located
between the ground-engaging outer side and the layer of cords.
34. The track claimed in claim 32, wherein the layer of reinforcing fabric is
located
between the inner side and the layer of cords.
35. The track claimed in any one of claims 32 to 34, wherein the layer of
reinforcing
fabric is spaced apart from the layer of cords in a thickness direction of the

endless track.
36. The track claimed in claim 35, wherein a spacing of the layer of
reinforcing
fabric and the layer of cords in the thickness direction of the track is
greater
than a thickness of the layer of reinforcing fabric.
37. The track claimed in any one of claims 32 to 36, wherein each of the cords

comprises a plurality of strands.
38. The track claimed in claim 27, comprising a plurality of cross bars
embedded
between the inner side and the ground-engaging outer side, spaced apart from
one another in the longitudinal direction of the track, and extending
transversally to the longitudinal direction of the track.


12

39. The track claimed in claim 38, wherein the layer of reinforcing fabric is
located
between the ground-engaging outer side and the cross bars.
40. The track claimed in claim 38, wherein the layer of reinforcing fabric is
located
between the inner side and the cross bars.
41. The track claimed in any one of claims 38 to 40, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.
42. The track claimed in claim 41, wherein the cross bars are located between
the
layer of cords and the ground-engaging outer side.
43. The track claimed in any one of claims 41 and 42, wherein the layer of
reinforcing fabric is located between the layer of cords and the cross bars.
44. The track claimed in any one of claims 38 to 43, wherein each of the cross
bars
comprises composite material.
45. The track claimed in any one of claims 27 to 44, wherein the layer of
reinforcing
fabric comprises reinforcing woven fabric.
46. The track claimed in claim 45, wherein the reinforcing woven fabric
comprises
nylon.
47. The track claimed in any one of claims 27 to 46, wherein, when operated at
a
given speed, the track consumes less power than if the track had an additional

layer of reinforcing fabric embedded between the inner side and the ground-
engaging outer side and spaced apart from the layer of reinforcing fabric.


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48. The track claimed in claim 47, wherein the given speed is above 60 miles
per
hour.
49. The track claimed in any one of claims 27 to 48, wherein certain ones of
the
traction projections are spaced apart from one another in a widthwise
direction
of the track.
50. The track claimed in any one of claims 27 to 49, wherein each of the
traction
projections has a height that varies along a longitudinal axis of the traction

projection.
51. The track claimed in any one of claims 27 to 50, wherein the vehicle is a
snowmobile and the track is a snowmobile track.
52. The track claimed in any one of claims 27 to 50, wherein the vehicle is an
all-
terrain vehicle (ATV) and the track is an ATV track.
53. A snowmobile comprising the track claimed in claim 51.
54. An ATV comprising the track claimed in claim 52.
55. A track for traction of a vehicle, the track being rubber-based and
comprising:
- an inner side for facing a drive wheel to impart motion to the track; and
- a ground-engaging outer side for engaging the ground on which the vehicle

travels, the ground-engaging outer side comprising a plurality of traction
projections distributed in a longitudinal direction of the track;
wherein a cross-section of the track normal to the longitudinal direction of
the
track has a single layer of reinforcing fabric embedded between the inner side

and the ground-engaging outer side.


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56. The track claimed in claim 55, wherein the single layer of reinforcing
fabric is
closer to a given one of the inner side and the ground-engaging outer side
than
to the other one of the inner side and the ground-engaging outer side in a
thickness direction of the track.
57. The track claimed in claim 55, wherein the single layer of reinforcing
fabric is
located such that a neutral area separating a region of compressive stress of
the cross-section of the track and a region of tensile stress of the cross-
section
of the track is closer to a given one of the inner side and the ground-
engaging
outer side than to the other one of the inner side and the ground-engaging
outer side in a thickness direction of the track.
58. The track claimed in claim 55, wherein the single layer of reinforcing
fabric is
closer to the ground-engaging outer side than to the inner side in a thickness

direction of the track.
59. The track claimed in claim 55, wherein the single layer of reinforcing
fabric is
located such that a neutral area separating a region of compressive stress of
the cross-section of the track and a region of tensile stress of the cross-
section
of the track is closer to the ground-engaging outer side than to the inner
side in
a thickness direction of the track.
60. The track claimed in any one of claims 55 to 59, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.
61. The track claimed in claim 60, wherein the single layer of reinforcing
fabric is
located between the ground-engaging outer side and the layer of cords.


15

62. The track claimed in claim 60, wherein the single layer of reinforcing
fabric is
located between the inner side and the layer of cords.
63. The track claimed in any one of claims 60 to 62, wherein the single layer
of
reinforcing fabric is spaced apart from the layer of cords in a thickness
direction
of the endless track.
64. The track claimed in claim 63, wherein a spacing of the single layer of
reinforcing fabric and the layer of cords in the thickness direction of the
track is
greater than a thickness of the single layer of reinforcing fabric.
65. The track claimed in any one of claims 60 to 64, wherein each of the cords

comprises a plurality of strands.
66. The track claimed in claim 55, comprising a plurality of cross bars
embedded
between the inner side and the ground-engaging outer side, spaced apart from
one another in the longitudinal direction of the track, and extending
transversally to the longitudinal direction of the track.
67. The track claimed in claim 66, wherein the single layer of reinforcing
fabric is
located between the ground-engaging outer side and the cross bars.
68. The track claimed in claim 66, wherein the single layer of reinforcing
fabric is
located between the inner side and the cross bars.
69. The track claimed in any one of claims 66 to 68, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.

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70. The track claimed in claim 69, wherein the cross bars are located between
the
layer of cords and the ground-engaging outer side.
71. The track claimed in any one of claims 69 and 70, wherein the single layer
of
reinforcing fabric is located between the layer of cords and the cross bars.
72. The track claimed in any one of claims 66 to 71, wherein each of the cross
bars
comprises composite material.
73. The track claimed in any one of claims 55 to 72, wherein the single layer
of
reinforcing fabric comprises reinforcing woven fabric.
74. The track claimed in claim 73, wherein the reinforcing woven fabric
comprises
nylon.
75. The track claimed in any one of claims 55 to 74, wherein, when operated at
a
given speed, the track consumes less power than if the cross-section of the
track had an additional layer of reinforcing fabric embedded between the inner

side and the ground-engaging outer side.
76. The track claimed in claim 75, wherein the given speed is above 60 miles
per
hour.
77. The track claimed in any one of claims 55 to 76, wherein certain ones of
the
traction projections are spaced apart from one another in a widthwise
direction
of the track.
78. The track claimed in any one of claims 55 to 77, wherein each of the
traction
projections has a height that varies along a longitudinal axis of the traction

projection.

17
79. The track claimed in any one of claims 55 to 78, wherein the vehicle is a
snowmobile and the track is a snowmobile track.
80. The track claimed in any one of claims 55 to 78, wherein the vehicle is an
all-
terrain vehicle (ATV) and the track is an ATV track.
81. A snowmobile comprising the track claimed in claim 79.
82. An ATV comprising the track claimed in claim 80.
83. A track for traction of a vehicle, the track being rubber-based and
comprising:
- an inner side for facing a drive wheel to impart motion to the track; and
- a ground-engaging outer side for engaging the ground on which the vehicle

travels, the ground-engaging outer side comprising a plurality of traction
projections distributed in a longitudinal direction of the track;
wherein the track has a single layer of reinforcing fabric embedded between
the inner side and the ground-engaging outer side along at least part of a
length of the track.
84. The track claimed in claim 83, wherein the single layer of reinforcing
fabric is
closer to a given one of the inner side and the ground-engaging outer side
than
to the other one of the inner side and the ground-engaging outer side in a
thickness direction of the track.
85. The track claimed in claim 83, wherein the single layer of reinforcing
fabric is
located such that a neutral area separating a region of compressive stress of
the track normal to the longitudinal direction of the track and a region of
tensile
stress of the track is closer to a given one of the inner side and the ground-
engaging outer side than to the other one of the inner side and the ground-
engaging outer side in a thickness direction of the track.

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86. The track claimed in claim 83, wherein the single layer of reinforcing
fabric is
closer to the ground-engaging outer side than to the inner side in a thickness

direction of the track.
87. The track claimed in claim 83, wherein the single layer of reinforcing
fabric is
located such that a neutral area separating a region of compressive stress of
the track and a region of tensile stress of the track is closer to the ground-
engaging outer side than to the inner side in a thickness direction of the
track.
88. The track claimed in any one of claims 83 to 87, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.
89. The track claimed in claim 88, wherein the single layer of reinforcing
fabric is
located between the ground-engaging outer side and the layer of cords.
90. The track claimed in claim 88, wherein the single layer of reinforcing
fabric is
located between the inner side and the layer of cords.
91. The track claimed in any one of claims 88 to 90, wherein the single layer
of
reinforcing fabric is spaced apart from the layer of cords in a thickness
direction
of the endless track.
92. The track claimed in claim 91, wherein a spacing of the single layer of
reinforcing fabric and the layer of cords in the thickness direction of the
track is
greater than a thickness of the single layer of reinforcing fabric.
93. The track claimed in any one of claims 88 to 92, wherein each of the cords

comprises a plurality of strands.

19
94. The track claimed in claim 83, comprising a plurality of cross bars
embedded
between the inner side and the ground-engaging outer side, spaced apart from
one another in the longitudinal direction of the track, and extending
transversally to the longitudinal direction of the track.
95. The track claimed in claim 94, wherein the single layer of reinforcing
fabric is
located between the ground-engaging outer side and the cross bars.
96. The track claimed in claim 94, wherein the single layer of reinforcing
fabric is
located between the inner side and the cross bars.
97. The track claimed in any one of claims 94 to 96, comprising a layer of
cords
embedded between the inner side and the ground-engaging outer side, the
cords extending generally parallel to one another and in the longitudinal
direction of the track.
98. The track claimed in claim 97, wherein the cross bars are located between
the
layer of cords and the ground-engaging outer side.
99. The track claimed in any one of claims 97 and 98, wherein the single layer
of
reinforcing fabric is located between the layer of cords and the cross bars.
100. The track claimed in any one of claims 94 to 99, wherein each of the
cross bars
comprises composite material.
101. The track claimed in any one of claims 83 to 100, wherein the single
layer of
reinforcing fabric comprises reinforcing woven fabric.
102. The track claimed in claim 101, wherein the reinforcing woven fabric
comprises
nylon.

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103. The track claimed in any one of claims 83 to 102, wherein, when operated
at a
given speed, the track consumes less power than if the track had an additional

layer of reinforcing fabric embedded between the inner side and the ground-
engaging outer side along the at least part of the length of the track.
104. The track claimed in claim 103, wherein the given speed is above 60 miles
per
hour.
105. The track claimed in any one of claims 83 to 104, wherein certain ones of
the
traction projections are spaced apart from one another in a widthwise
direction
of the track.
106. The track claimed in any one of claims 83 to 105, wherein each of the
traction
projections has a height that varies along a longitudinal axis of the traction

projection.
107. The track claimed in any one of claims 83 to 106, wherein the vehicle is
a
snowmobile and the track is a snowmobile track.
108. The track claimed in any one of claims 83 to 106, wherein the vehicle is
an all-
terrain vehicle (ATV) and the track is an ATV track.
109. A snowmobile comprising the track claimed in claim 107.
110. An ATV comprising the track claimed in claim 108.

Description

CA 02865698 2014-10-01
1
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

CA 02865698 2015-01-21
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2
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 track for traction of a snowmobile or all-terrain vehicle (ATV). The
endless
track comprises a rubber-based body having an inner side for facing a drive
wheel of
the snowmobile or ATV and a ground-engaging outer side for engaging the ground

on which the snowmobile or ATV travels. The endless track further comprises a
plurality of rubber-based traction projections projecting outwardly from the
ground-
engaging outer side and a layer of reinforcing fabric embedded within the
rubber-
based body. The endless track is free of reinforcing fabric extending along
the
endless track between the inner side and the layer of reinforcing fabric and
free of
reinforcing fabric extending along the endless track between the ground-
engaging
outer side and the layer of reinforcing fabric.

CA 02865698 2015-01-21
2A
[0007B] In accordance with another aspect of the invention, there is
provided
an endless track for traction of a snowmobile or all-terrain vehicle (ATV).
The
endless track comprises a rubber-based body having an inner side for facing a
drive
wheel of the snowmobile or ATV and a ground-engaging outer side for engaging
the
ground on which the snowmobile or ATV travels. The endless track further
comprises
a plurality of rubber-based traction projections projecting outwardly from the
ground-
engaging outer side and a layer of reinforcing fabric embedded within the
rubber-
based body. The endless track does not comprise two layers of reinforcing
fabric
embedded within the rubber-based body and spaced apart from one another.
[0007C] In accordance with another aspect of the invention, there is
provided
an endless track for traction of a snowmobile or all-terrain vehicle (ATV),
the endless
track comprises a rubber-based body having an inner side for facing a drive
wheel of
the snowmobile or ATV and a ground-engaging outer side for engaging the ground

on which the snowmobile or ATV travels. The endless track further comprises a
plurality of rubber-based traction projections projecting outwardly from the
ground-
engaging outer side and a layer of reinforcing fabric embedded within the
rubber-
based body. When operated at a given speed, the endless track consumes less
power than if the endless track had an additional layer of reinforcing fabric
embedded within the rubber-based body and spaced apart from the layer of
reinforcing fabric.
[00070] In accordance with another aspect of the invention, there is
provided a
track for traction of a vehicle. The track is rubber-based and comprises an
inner side
for facing a drive wheel to impart motion to the track, a ground-engaging
outer side
for engaging the ground on which the vehicle travels, and a layer of
reinforcing fabric
embedded between the inner side and the ground-engaging outer side. The ground-

engaging outer side comprises a plurality of traction projections distributed
in a
longitudinal direction of the track. A segment of the track is free of
reinforcing fabric

CA 02865698 2015-01-21
2B
between the inner side and the layer of reinforcing fabric and between the
ground-
engaging outer side and the layer of reinforcing fabric.
[0007E] In accordance with another aspect of the invention, there is
provided a
track for traction of a vehicle. The track is rubber-based and comprises an
inner side
for facing a drive wheel to impart motion to the track, and a ground-engaging
outer
side for engaging the ground on which the vehicle travels. The ground-engaging

outer side comprises a plurality of traction projections distributed in a
longitudinal
direction of the track. A cross-section of the track normal to the
longitudinal direction
of the track has a single layer of reinforcing fabric embedded between the
inner side
and the ground-engaging outer side.
[0007F] In accordance with another aspect of the invention, there is
provided a
track for traction of a vehicle. The track is rubber-based and comprises an
inner side
for facing a drive wheel to impart motion to the track and a ground-engaging
outer
side for engaging the ground on which the vehicle travels. The ground-engaging

outer side comprises a plurality of traction projections distributed in a
longitudinal
direction of the track. The track has a single layer of reinforcing fabric
embedded
between the inner side and the ground-engaging outer side along at least part
of a
length of the track.
[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:

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[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.

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[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

CA 02865698 2014-10-01
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.

Representative Drawing