CHENILLE DE MOTONEIGE POUR NEIGE POUDREUSE

POWDER SNOW TRACK FOR SNOWMOBILE

Abrégé français

La présente invention propose une courroie de chenille sans fin qui procure une meilleure traction dun véhicule à chenilles sur une plage de conditions de surface, en offrant une bande de roulement dune section non uniforme.

Abrégé anglais

The present invention provides an endless track belt allowing an enhanced traction of a tracked vehicle over a range of surface conditions, by providing tread of a non-uniform section.

Revendications

6
CLAIMS:
1. A track comprising an endless drive belt with a ground-engaging surface
bearing a series of transversally extending treads, wherein each tread
comprises a flexible top part operable to bend and thereby cause a
compacting action that compacts powder snow into packed snow, and a
rigid bottom part operable to cause grabbing action that provides traction on
the packed snow.
2. The track of claim 1, wherein the endless belt is made of one of a
flexible
rubber and a flexible rubber reinforced by rods, and the treads are made of
a rubber material.
3. The track of claim 2, wherein said rods are embedded in a material of
the
belt in a region of the treads.
4. The track of claim 2, wherein said rods are one of metallic and plastic.
5. The track of claim 2, wherein some of the treads are located at a
position of
the rods.
6. The track of claim 2, further comprising longitudinal perforated bands
supporting steel fasteners.
7. The track of claim 1, said ground-engaging surface further comprising a
longitudinal texture made of adjacent longitudinal ribs.
8. The track of claim 7, the track having a width of 15 inches, said
longitudinal
texture comprising between 10 and 300 ribs of a height between about 10
and 250 milli-inches, over the width of the track.

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9. The track of claim 1, for one of a recreational vehicle, a snowmobile
and an
ATV.
10. An endless belt for a snowmobile track having a ground engaging surface
bearing treads, each tread having a top part and a bottom part, said top part
being flexible and operable to bend and cause a compacting action on the
powder snow and transform it into packed snow, and said bottom part being
rigid and operable to create a grabbing action on the packed snow.
11. The endless belt of claim 10, said ground-engaging surface further
comprising a longitudinal texture made of adjacent longitudinal ribs.
12. A track for traction of a vehicle, the track being mountable around a
plurality
of wheels which comprises a drive wheel for imparting motion to the track,
the track comprising elastomeric material to flex around the wheels, the
track comprising:
- an inner surface for facing the wheels;
- a ground-engaging outer surface for engaging the ground; and
- a plurality of traction projections projecting from the ground-engaging
outer surface and distributed in a longitudinal direction of the track,
each traction projection being integrally formed with the ground-
engaging outer surface and comprising a top part and a bottom part, the
top part of the traction projection being more flexible than the bottom
part of the traction projection to bend relative to the bottom part of the
traction projection and compact matter on the ground when the traction
projection engages the ground.
13. The track of claim 12, wherein a cross-section of the top part of the
traction
projection normal to a height direction of the traction projection is smaller
than a cross-section of the bottom part of the traction projection normal to
the height direction of the traction projection.

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14. The track of any one of claims 12 and 13, wherein a dimension of the top
part of the traction projection in the longitudinal direction of the track is
smaller than a dimension of the bottom part of the traction projection in the
longitudinal direction of the track.
15. The track of claim 14, wherein the dimension of the top part of the
traction
projection in the longitudinal direction of the track is less than half of the

dimension of the bottom part of the traction projection in the longitudinal
direction of the track.
16. The track of claim any one of claims 12 to 15, wherein the traction
projection tapers from the bottom part of the traction projection towards the
top part of the traction projection.
17. The track of claim 16, wherein the traction projection tapers from the
bottom
part of the traction projection to the top part of the traction projection.
18. The track of any one of claims 12 to 17, wherein the top part of the
traction
projection is shorter than the bottom part of the traction projection in a
height direction of the traction projection.
19. The track of any one of claims 12 to 18, wherein a height of a first one
of
the traction projections is greater than a height of a second one of the
traction projections.
20. The track of claim 19, wherein the height of the second one of the
traction
projections is less than half the height of the first one of the traction
projections.

9
21. The track of any one of claims 19 and 20, wherein the first one of the
traction projections and the second one of the traction projections are
adjacent in a widthwise direction of the track.
22. The track of any one of claims 12 to 21, wherein the ground-engaging outer

surface comprises a texture including a plurality of longitudinal rigidifiers
to
increase a rigidity of the track in the longitudinal direction of the track.
23. The track of claim 22, wherein the longitudinal rigidifiers comprise ribs
extending generally in the longitudinal direction of the track.
24. The track of claim 23, wherein a ratio of the number of ribs over a width
of
the track is at least 0.67 ribs/inch.
25. The track of claim 23, wherein a ratio of the number of ribs over a width
of
the track is between 0.67 ribs/inch and 20 ribs/inch.
26. The track of any one of claims 22 to 25, wherein plural ones of the
longitudinal rigidifiers are located within a span of a given one of the
traction
projections in a widthwise direction of the track.
27. The track of claim 26, wherein the plural ones of the longitudinal
rigidifiers
comprise at least five of the longitudinal rigidifiers.
28. The track of claim 26, wherein the plural ones of the longitudinal
rigidifiers
comprise at least ten of the longitudinal rigidifiers.
29. The track of claim 26, wherein the plural ones of the longitudinal
rigidifiers
comprise at least twenty of the longitudinal rigidifiers.

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30. The track of claim 26, wherein the plural ones of the longitudinal
rigidifiers
comprise at least thirty of the longitudinal rigidifiers.
31. The track of any one of claims 22 to 30, wherein the longitudinal
rigidifiers
are distributed over at least a majority of a width of the track.
32. The track of claim 31, wherein the longitudinal rigidifiers are
distributed over
substantially an entirety of the width of the track.
33. The track of any one of claims 22 to 32, wherein a height of a given one
of
the longitudinal rigidifiers is at least 10 milli-inches.
34. The track of any one of claims 22 to 32, wherein a height of a given one
of
the longitudinal rigidifiers is no more than 250 milli-inches.
35. The track of any one of claims 22 to 32, wherein a height of a given one
of
the longitudinal rigidifiers is between 10 milli-inches and 250 milli-inches.
36. The track of any one of claims 12 to 35, comprising a plurality of
reinforcing
rods disposed within the elastomeric material and extending transversally to
the longitudinal direction of the track.
37. The track of claim 12, wherein the bottom part of the traction projection
is
configured to perform a grabbing action on the matter on the ground that
has been compacted by the track.
38. The track of any one of claims 12 to 37, wherein the matter on the ground
comprises snow or sand.
39. The track of any one of claims 12 to 38, wherein the vehicle is a
snowmobile and the track is a snowmobile track.

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40. The track of any one of claims 12 to 38, wherein the vehicle is an ATV and

the track is an ATV track.
41. A vehicle comprising the track of any one of claims 12 to 38.
42. The vehicle of claim 41, wherein the vehicle is a snowmobile.
43. The vehicle of claim 41, wherein the vehicle is an ATV.

Description

CA 02512399 2005-07-15
1
TITLE OF THE INVENTION
Powder snow track for snowmobile
FIELD OF THE INVENTION
[0001] The present invention pertains to an endless track. More
specifically, the present invention is concerned with a track having an
enhanced traction performance over a range of surfaces.
BACKGROUND OF THE INVENTION
[0002] A propulsion system generally found on tracked vehicles
such as snowmobiles consists of a pair of longitudinally spaced apart wheel
structures arranged on opposite sides of the vehicle chassis, which is driven
by
a pair of endless, substantially inextensible belts, each having an inner
surface
and a ground-engaging surface.
[0003] The inner surface is provided with a series of longitudinally
spaced members, which guide the track relative to driving and tracking wheels
forming part of the wheel structures. The ground-engaging surface of the belt
is
formed of a plurality of longitudinally spaced tread members that provide
traction to the vehicle when traveling on various ground conditions. The
ground-engaging surface of the track may comprise a series of integral
profiles
having various configurations to provide traction to the snowmobile.
[0004] Therefore, a track is usually formed of a body of elastomeric
material, the ground-engaging surface thereof displaying a series of
transverse
profiles that provide traction for the snowmobile as it travels over a
surface,

2A
while the inner surface of the track displays a series of integral lugs, which
are
contacted by sprocket wheels that drive the snowmobile track in rotation.
[0005] In spite
of a number of developments in the field of tracks,
there is still a need in the art for a track allowing efficient traction of a
tracked
vehicle over a range of surface conditions.
SUMMARY OF THE INVENTION
[0006] There is
provided a track comprising an endless drive belt
with a ground-engaging surface bearing a series of transversally extending
treads, wherein each tread comprises a flexible top part operable to bend and
thereby cause a compacting action that compacts powder snow into packed
snow, and a rigid bottom part operable to cause grabbing action that provides
traction on the packed snow.
[0007] There is
also provided an endless belt for a snowmobile track
having a ground engaging surface bearing treads, each tread having a top part
and a bottom part, said top part being flexible and operable to bend and cause

a compacting action on the powder snow and transform it into packed snow,
and said bottom part being rigid and operable to create a grabbing action on
the packed snow.
[0007A] There is
also provided a track for traction of a vehicle. The track
is mountable around a plurality of wheels which comprises a drive wheel for
imparting motion to the track. The track comprises elastomeric material to
flex
around the wheels. The track comprises an inner surface for facing the wheels,

a ground-engaging outer surface for engaging the ground, and a plurality of
traction projections projecting from the ground-engaging outer surface and
distributed in a longitudinal direction of the track. Each traction projection
being
integrally formed with the ground-engaging outer surface and comprises a top
CA 2512299 2017-08-24

2B
part and a bottom part. The top part OT me traction projection is more
flexible
than the bottom part of the traction projection to bend relative to the bottom

part of the traction projection and compact matter on the ground when the
traction projection engages the ground.
[0007B] There is
also provided a track for traction of a vehicle. The track
is mountable around a plurality of wheels which comprises a drive wheel for
imparting motion to the track. The track comprises elastomeric material to
flex
around the wheels. The track comprises an inner surface for facing the wheels,

a ground-engaging outer surface for engaging the ground, and a plurality of
traction projections projecting from the ground-engaging outer surface and
distributed in a longitudinal direction of the track. A given one of the inner

surface and the ground-engaging outer surface comprises a texture including a
plurality of longitudinal rigidifiers to increase a rigidity of the track in
the
longitudinal direction of the track.
[0007C] There is
also provided a track for traction of a vehicle. The track
is mountable around a plurality of wheels which comprises a drive wheel for
imparting motion to the track. The track comprises elastomeric material to
flex
around the wheels. The track comprises an inner surface for facing the wheels,

a ground-engaging outer surface for engaging the ground, and a plurality of
traction projections projecting from the ground-engaging outer surface and
distributed in a longitudinal direction of the track. The ground-engaging
outer
surface comprises a texture including a plurality of longitudinal rigidifiers
to
increase a rigidity of the track in the longitudinal direction of the track.
[0008] Other
objects, advantages and features of the present
invention will become more apparent upon reading of the following non-
restrictive description of specific embodiments thereof, given by way of
example only with reference to the accompanying drawings.
CA 2512299 2017-08-24

CA 02512399 2005-07-15
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BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the appended drawings:
[0010] Figure 1 is a top partial perspective view of a track according
to an embodiment of the present invention;
[0011] Figure 2 is a top partial view of the track of Figure 1; and
[0012] Figure 3 is a cross section of a tread extending from a
ground-engaging surface of the track of Figures 1 and 2.
DESCRIPTION OF SPECIFIC EMBODIMENTS
[0013] Generally stated, the present invention provides a track that
allows an improved performance over a range of surfaces, including snow in a
variety of states, from powder snow to hard snow, or sand from wet to
hardened sand for example.
[0014] Turning to Figures 1 and 2 of the appended drawings, a track
to an embodiment of the present invention will now be described.
[0015] A track 10 typically comprises an endless drive belt 12 trained
around drive sprockets or wheels (not shown) for driving the belt 12 in an
endless path.
[0016] The belt 12 has an inner surface face (not seen) and a
ground-engaging surface 16, which, as it passes along a lower run of the belt
12, engages a surface (not shown) to be traversed. The inner track surface is

CA 02512299 2013-07-08
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typically provided with spaced drive lugs, which are spaced along the length
of
the inside of the belt 12 for engaging the drive wheels (not shown) as is well

known in the art.
[0017] The ground-engaging surface 16 comprises a series of
transversally extending treads 20 and 21 extending generally from a center of
the ground-engaging surface 16 to lateral edges thereof. The treads 20, 21
may be made of a rubber material.
[0018] The endless belt 12 may be made of flexible rubber or flexible
rubber reinforced by rods to strengthen the track, as is well known in the
art.
Typically, conventional tracks include, embedded in the rubber material of the

body of the belt 12 and in the region the treads 20, 21, such reinforcing
rods,
either metallic or plastic, to provide transverse rigidity to the track 10.
Moreover,
the track 12 may comprise longitudinal perforated bands 30 supporting steel
fasteners, as known in the art.
[0019] As illustrated in Figure 3, each tread 20, 21 has a straight
profile, devoid of lateral curvature, from a top part 22 thereof to a bottom
part
24 thereof, and an outer edge 32 of the top part 22 is generally flat.
Moreover,
the top part 22 has a section smaller than the bottom part thereof 24, the
bottom part 24 thus being more massive and rigid. The reduced section of the
top part 22 provides increased flexibility of this part of the tread 20, 21.
[0020] It is found that on powder snow for example, the top parts 22
are allowed to bend, thereby compacting the snow instead of cutting
therethrough, which results in an enhanced traction of the tracked vehicle
over
the powder snow. Indeed such a compacting effect assists the vehicle into
uplifting and extracting itself from heavy snow, instead of digging itself
deeper

CA 02512299 2015-11-25
therein. On packed snow, enhanced traction is also achieved through a grabbing

action of the bottom parts 24.
[0021] Such a
non-uniformity between the top and bottom parts of the treads
therefore allows an enhanced traction over a range of snow conditions.
Moreover, it
is found that it contributes to extending the service life of the track.
[0022] It is
further found that treads 21 located at the position of the
reinforcing rods of the track during the molding stage of the track are
efficient in
allowing an easier fabrication process. In order not to increase the weight of
the
track, these treads 21 may be provided with a reduced height compared to
treads
20.
[0023] The
ground-engaging surface 16 may further comprise a longitudinal
texture 26 made of adjacent longitudinal ribs. For example, there may between
about 10 and 300 ribs of a height between about 10 and 250 milli-inches, over
a
width of the track of 15 inches. Such longitudinal texture is found to
increase rigidity
in flexion of the track 10.
[0024]
Obviously, such a track may be used for recreational vehicles,
snowmobiles or ATV for example.
[0025] Although
the present invention has been described hereinabove by
way of specific embodiments thereof, it can be modified, without departing
from the
nature of the subject invention as described herein.

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