CHENILLES POUR VEHICULE TOUT TERRAIN

TRACK ASSEMBLY FOR AN ALL-TERRAIN VEHICLE

Abrégé français

La présente invention a trait à des assemblages de chenilles pour un véhicule tout terrain qui le rendent maniable et efficace sur une gamme de surfaces instables, irrégulières, stables et planes. Ces assemblages sont conçus pour maintenir sous tension les bandes sans fin de manière quelles demeurent dans le bon axe et prévenir un desserrage accidentel, tout en ayant un contact ponctuel localisé avec une surface et en réduisant simultanément les dommages infligés sur le terrain.

Abrégé anglais

The present invention is concerned with track assemblies for an all-terrain vehicle, which make it maneuverable and effective upon a variety of unstable, uneven, stable and even surfaces, while designed to maintain tension upon the endless track belts to keep them in their due course and prevent accidental loosening while having a punctually localized surface contact with a ground surface, and at the same time reducing the damages inflicted on the terrain.

Revendications

17
CLAIMS:
1) A track assembly for a reduced-size vehicle designed primarily for off-
highway
usage, over undeveloped roads or other unprepared surfaces, the track
assembly having a leading end and a trailing end and comprising:
a) an endless track having an outer ground engaging surface and an opposite
inner surface; and
b) a plurality of wheels for supporting and driving the endless track, the
plurality
of wheels including:
i) a leading idler and a trailing idler, the leading and trailing idlers being
in a
spaced apart relationship, a segment of the endless track extending
between the leading and trailing idlers defining a ground engaging run, the
leading idler having a first axis of rotation, the trailing idler having a
second axis of rotation; and
ii) a drive wheel having a third axis of rotation, the drive wheel being in
driving engagement with the endless track for imparting movement to the
endless track, the drive wheel overlapping with one of the leading idler
and the trailing idler when viewed in a plane normal to the third axis of
rotation.
2) A track assembly as defined in claim 1, comprising a support structure
having:
a) a center portion rotatably supported at the third axis of rotation;
b) a first support arm mounted to the center portion and extending along a
radial
direction of the drive wheel toward the leading idler of the track assembly;
and
c) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing idler of the track
assembly.
3) A track assembly as defined in claim 2, wherein the first support arm
defines a
first angle with an imaginary horizontal axis which extends through the third
axis

18
of rotation, the second support arm defines a second angle with the imaginary
horizontal axis, the first angle being different from the second angle.
4) A track assembly as defined in any one of claims 1 to 3, wherein the drive
wheel
is in rolling contact with the inner surface of the ground engaging run.
5) A track assembly as defined in any one of claims 1 to 4, wherein the drive
wheel
is in overlapping relationship with the trailing idler, when viewed in a plane
normal to the third axis of rotation.
6) A track assembly as defined in claim 2, wherein one of the first and second
support arms is longer than the other of the first and second support arms.
7) A track assembly as defined in claim 2, wherein the first support arm and
the
second support arm define an obtuse angle therebetween.
8) A track assembly as defined in any one of claims 1 to 7, wherein the
endless
track is free of stiffening rods extending in a transverse direction of the
endless
track.
9) A track assembly as defined in any one of claims 1 to 8, wherein the
profile of the
endless track in a transverse direction of the endless track is generally
convex.
10)A track assembly as defined in any one of claims 1 to 9, wherein the
endless
track comprises drive lugs projecting from the inner surface for engagement by
the drive wheel.
11)A track assembly as defined in any one of claims 1 to 10, wherein the
endless
track has a pair of opposite lateral edge portions and a central portion
between

19
the lateral edge portions, the opposite lateral edge portions being free of
stiffening rods extending in a transverse direction of the endless track.
12)A track assembly as defined in claim 11, wherein the central portion
includes one
or more stiffening rods extending in a transverse direction of the endless
track,
the one or more stiffening rods being shorter than a transverse dimension of
the
endless track.
13)A track assembly as defined in any one of claims 1 to 7, wherein the
endless
track includes a plurality of track segments, each track segment including a
drive
lug extending inwardly from the inner surface for engaging the drive wheel,
and a
traction projection projecting from the outer ground engaging surface, the
drive
lug registering in a longitudinal direction of the endless track with the
traction
projection, the portion of the track segment defined between the drive lug and
the
traction projection being free of a stiffening rod extending transversally of
the
endless track.
14)A track assembly as defined in any one of claims 1 to 7, wherein the
endless
track comprises a plurality of drive lugs longitudinally spaced apart along
the
track for sequentially engaging the drive wheel such that rotation of the
drive
wheel imparts motion to the endless track to propel the vehicle, the endless
track
comprising a plurality of traction projections projecting from the outer
ground
engaging surface, the traction projections being longitudinally spaced apart
and
registering with respective drive lugs, the endless track being free of
stiffening
rods extending transversally of the endless track at locations of the endless
track
at which a drive lug registers with a traction projection.
15)A track assembly as defined in any one of claims 1 to 14, wherein the third
axis
of rotation is located above the first axis of rotation and the second axis of
rotation.

20
16)A track assembly as defined in any one of claims 1 to 15, wherein the drive
wheel has a periphery bound between a first upper horizontal imaginary plane
and a first lower horizontal imaginary plane, one of the leading and trailing
idlers
having a periphery bound between a second upper horizontal imaginary plane
and a second lower horizontal imaginary plane, the first lower horizontal
imaginary plane being positioned below the second upper horizontal imaginary
plane.
17)A track assembly as defined in any one of claims 1 to 16, wherein the drive
wheel has a periphery bound between a first upper horizontal imaginary plane
and a first lower horizontal imaginary plane, the leading idler having a
periphery
bound between a second upper horizontal imaginary plane and a second lower
horizontal imaginary plane, the trailing idler having a periphery bound
between a
third upper horizontal imaginary plane and a third lower horizontal imaginary
plane, the first lower horizontal imaginary plane being positioned below the
second upper horizontal imaginary plane and below the third upper horizontal
imaginary plane.
18)A track assembly as defined in any one of claims 1 to 17, wherein the
plurality of
wheels imparts a generally triangular path of travel to the endless track.
19)A track assembly as defined in any one of claims 1 to 18, wherein the
plurality of
wheels defines a track supporting and guiding arrangement that is in rolling
contact with the inner surface at a plurality of locations.
20)A track assembly as defined in any one of claims 1 to 19, wherein the drive
wheel has an extent along the third axis of rotation that is less than a
transverse
dimension of the endless track.

21
21)A track assembly as defined in any one of claims 1 to 20, wherein the drive
wheel has a periphery extending between a periphery and an axis of rotation of
the one of the leading idler and the trailing idler.
22)A track assembly as defined in any one of claims 1 to 21, wherein the track
assembly is steerable by changing an orientation of the track assembly by a
steering mechanism of the vehicle.
23)A set of track assemblies for a reduced-size vehicle designed primarily for
off-
highway usage, over undeveloped roads or other unprepared surfaces, wherein
each of at least two of the track assemblies is as defined in any one of
claims 1
to 22.
24)A reduced-size vehicle designed primarily for off-highway usage, over
undeveloped roads or other unprepared surfaces, the reduced size vehicle
including a track assembly as defined in any one of claims 1 to 22.
25) A reduced-size vehicle as defined in claim 24, wherein the vehicle is an
all-
terrain vehicle (ATV).
26)A reduced-size vehicle as defined in claim 25, wherein the ATV comprises
handlebars.
27)A reduced-size vehicle designed primarily for off-highway usage, over
undeveloped roads or other unprepared surfaces, the reduced size vehicle
including a set of track assemblies as defined in claim 23.
28) A reduced-size vehicle as defined in claim 27, wherein the vehicle is an
all-
terrain vehicle (ATV).

22
29)A reduced-size vehicle as defined in claim 28, wherein the ATV comprises
handlebars.
30)An all-terrain vehicle (ATV) comprising two track assemblies as defined in
any
one of claims 1 to 22, the two track assemblies being mounted on a common
axle of the ATV.
31)An all-terrain vehicle (ATV) comprising two steerable track assemblies as
defined
in claim 22, wherein the steering mechanism includes a rod for controlling an
angular orientation of at least one of the two steerable track assemblies, the
rod
being coupled to the at least one of the two steerable track assemblies.
32)A track assembly for a reduced-size vehicle designed primarily for off-
highway
usage, over undeveloped roads or other unprepared surfaces, the track
assembly comprising:
a) an endless track having an outer ground engaging surface and an opposite
inner surface; and
b) a plurality of wheels for supporting and driving the endless track, the
plurality
of wheels including:
i) an idler having a first axis of rotation; and
ii) a drive wheel having a second axis of rotation, the drive wheel being in
driving engagement with the endless track for imparting movement to the
endless track;
the sum of a radius of the idler and a radius of the drive wheel exceeding a
distance between the first axis of rotation and the second axis of rotation.
33)A track assembly as defined in claim 32, wherein the idler is a trailing
idler, the
plurality of wheels including a leading idler in a spaced apart relationship
with the
trailing idler.

23
34)A track assembly as defined in claim 33, including a support structure
having:
a) a center portion rotatably supported at the second axis of rotation;
b) a first support arm mounted to the center portion and extending along a
radial
direction of the drive wheel toward the leading idler;
c) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing idler.
35)A track assembly as defined in claim 34, wherein the first support arm
defines a
first angle with an imaginary horizontal axis which extends through the second
axis of rotation, the second support arms defines a second angle with the
imaginary horizontal axis, the first angle being different from the second
angle.
36)A track assembly as defined in any one of claims 33 to 35, wherein the
drive
wheel is in rolling contact with the inner surface of a ground engaging run of
the
endless track defined between the leading idler and the trailing idler.
37)A track assembly as defined in claim 34, wherein one of the first and
second
support arms is longer than the other of the first and second support arms.
38)A track assembly as defined in claim 34, wherein the first support arm and
the
second support arm define an obtuse angle therebetween.
39)A track assembly as defined in any one of claims 32 to 38, wherein the
endless
track is free of stiffening rods extending in a transverse direction of the
endless
track.
40)A track assembly as defined in any one of claims 32 to 39, wherein the
profile of
the endless track in a transverse direction of the endless track is generally
convex.

24
41)A track assembly as defined in any one of claims 32 to 40, wherein the
endless
track comprises drive lugs projecting from the inner surface for engagement by
the drive wheel.
42)A track assembly as defined in any one of claims 32 to 38, wherein the
endless
track has a pair of opposite lateral edge portions and a central portion
between
the lateral edge portions, the opposite lateral edge portions being free of
stiffening rods extending in a transverse direction of the endless track.
43)A track assembly as defined in claim 42, wherein the central portion
includes one
or more stiffening rods extending in a transverse direction of the endless
track,
the one or more stiffening rods being shorter than a transverse dimension of
the
endless track.
44)A track assembly as defined in any one of claims 32 to 38, wherein the
endless
track includes a plurality of track segments, each track segment including a
drive
lug extending inwardly from the inner surface for engaging the drive wheel,
and a
traction projection projecting from the outer ground engaging surface, the
drive
lug registering in a longitudinal direction of the endless track with the
traction
projection, the portion of the track segment defined between the drive lug and
the
traction projection being free of a stiffening rod extending transversally of
the
endless track.
45)A track assembly as defined in any one of claims 32 to 38, wherein the
endless
track comprises a plurality of drive lugs longitudinally spaced apart along
the
track for sequentially engaging the drive wheel such that rotation of the
drive
wheel imparts motion to the endless track to propel the vehicle, the endless
track
comprising a plurality of traction projections projecting from the outer
ground
engaging surface, the traction projections being longitudinally spaced apart
and
registering with respective drive lugs, the endless track being free of
stiffening

25
rods extending transversally of the endless track at locations of the endless
track
at which a drive lug registers with a traction projection.
46)A track assembly as defined in any one of claims 32 to 45, wherein the
second
axis of rotation is located above the first axis of rotation.
47)A track assembly as defined in any one of claims 33 to 46, wherein the
drive
wheel has a periphery bound between a first upper horizontal imaginary plane
and a first lower horizontal imaginary plane, one of the leading and trailing
idlers
having a periphery bound between a second upper horizontal imaginary plane
and a second lower horizontal imaginary plane, the first lower horizontal
imaginary plane being positioned below the second upper horizontal imaginary
plane.
48)A track assembly as defined in any one of claims 33 to 46, wherein the
drive
wheel has a periphery bound between a first upper horizontal imaginary plane
and a first lower horizontal imaginary plane, the leading idler having a
periphery
bound between a second upper horizontal imaginary plane and a second lower
horizontal imaginary plane, the trailing idler having a periphery bound
between a
third upper horizontal imaginary plane and a third lower horizontal imaginary
plane, the first lower horizontal imaginary plane being positioned below the
second upper horizontal imaginary plane and below the third upper horizontal
imaginary plane.
49)A track assembly as defined in any one of claims 32 to 48, wherein the
plurality
of wheels imparts a generally triangular path of travel to the endless track.
50)A track assembly as defined in any one of claims 32 to 49, wherein the
drive
wheel has an extent along the second axis of rotation that is less than a
transverse dimension of the endless track.

26
51)A track assembly as defined in any one of claims 32 to 50, wherein the
track
assembly is steerable by changing an orientation of the track assembly by a
steering mechanism of the vehicle.
52)A set of track assemblies for a reduced-size vehicle designed primarily for
off-
highway usage, over undeveloped roads or other unprepared surfaces, wherein
each of at least two of the track assemblies is as defined in any one of
claims 32
to 51.
53)A reduced-size vehicle designed primarily for off-highway usage, over
undeveloped roads or other unprepared surfaces, the reduced size vehicle
including a track assembly as defined in any one of claims 32 to 51.
54) A reduced-size vehicle as defined in claim 53, wherein the vehicle is an
all-
terrain vehicle (ATV).
55)A reduced-size vehicle as defined in claim 54, wherein the ATV comprises
handlebars.
56)A reduced-size vehicle designed primarily for off-highway usage, over
undeveloped roads or other unprepared surfaces, the reduced size vehicle
including a set of track assemblies as defined in claim 52.
57) A reduced-size vehicle as defined in claim 56, wherein the vehicle is an
all-
terrain vehicle (ATV).
58)A reduced-size vehicle as defined in claim 57, wherein the ATV comprises
handlebars.

27
59)An all-terrain vehicle (ATV) comprising two track assemblies as defined in
any
one of claims 32 to 51, the two track assemblies being mounted on a common
axle of the AN.
60)An all-terrain vehicle (ATV) comprising two steerable track assemblies as
defined
in claim 51, wherein the steering mechanism includes a rod for controlling an
angular orientation of at least one of the two steerable track assemblies, the
rod
being coupled to the at least one of the two steerable track assemblies.
61)A track assembly for providing traction to an all-terrain vehicle (ATV),
the track
assembly being configured to replace a ground-engaging wheel of the ATV, the
track assembly comprising:
a) a plurality of wheels including:
- a drive wheel; and
- a leading idler wheel and a trailing idler wheel spaced apart from the
leading idler wheel in a longitudinal direction of the track assembly;
the drive wheel and a given one of the leading idler wheel and the trailing
idler
wheel overlapping in the longitudinal direction of the track assembly; and
b) an endless track disposed around the plurality of wheels and comprising:
- an inner surface for facing the plurality of wheels, the drive wheel
being
rotatable to impart motion to the endless track;
- a ground-engaging outer surface opposite to the inner surface; and
- a plurality of traction projections projecting from the ground-engaging
outer surface.
62)A track assembly as defined in claim 61, wherein the given one of the
leading
idler wheel and the trailing idler wheel is the trailing idler wheel.

28
63)A track assembly as defined in any one of claims 61 and 62, wherein a
distance
between an axis of rotation of the drive wheel and an axis of rotation of the
leading idler wheel in the longitudinal direction of the track assembly is
different
from a distance between the axis of rotation of the drive wheel and an axis of
rotation of the trailing idler wheel in the longitudinal direction of the
track
assembly.
64)A track assembly as defined in claim 63, wherein the distance between the
axis
of rotation of the drive wheel and the axis of rotation of the leading idler
wheel in
the longitudinal direction of the track assembly is greater than the distance
between the axis of rotation of the drive wheel and the axis of rotation of
the
trailing idler wheel in the longitudinal direction of the track assembly.
65)A track assembly as defined in any one of claims 61 to 64, comprising a
support
structure supporting the leading idler wheel and the trailing idler wheel and
comprising a first arm extending downwardly and forwardly towards the leading
idler wheel and a second arm extending downwardly and rearwardly towards the
trailing idler wheel.
66)A track assembly as defined in claim 65, wherein the first arm is longer
than the
second arm.
67)A track assembly as defined in any one of claims 61 to 66, wherein the
drive
wheel engages a bottom run of the endless track that extends between the
leading idler wheel and the trailing idler wheel.
68)A track assembly as defined in any one of claims 61 to 67, wherein the
endless
track is free of stiffening rods extending transversally to a longitudinal
direction of
the endless track.

29
69)A track assembly as defined in any one of claims 61 to 68, wherein a
profile of
the endless track in a transversal direction of the endless track is generally
convex.
70)A track assembly as defined in any one of claims 61 to 69, wherein the
endless
track comprises a plurality of drive lugs projecting from the inner surface
for
engaging the drive wheel.
71) A track assembly as defined in any one of claims 61 to 67, wherein the
endless
track has a pair of lateral edge portions and a central portion between the
lateral
edge portions, the lateral edge portions being free of stiffening rods
extending
transversally to a longitudinal direction of the endless track.
72)A track assembly as defined in claim 71, wherein the central portion
includes one
or more stiffening rods extending transversally to the longitudinal direction
of the
endless track and shorter than a transverse dimension of the endless track.
73)A track assembly as defined in any one of claims 61 to 67, wherein the
endless
track includes a plurality of track segments, each track segment including (i)
a
drive lug projecting from the inner surface to engage the drive wheel and (ii)
a
given one of the traction projections that registers with the drive lug in a
longitudinal direction of the endless track, the track segment being free of a
stiffening rod extending transversally of the endless track between the drive
lug
and the given one of the traction projections.
74)A track assembly as defined in any one of claims 61 to 67, wherein the
endless
track comprises a plurality of drive lugs projecting from the inner surface
for
engaging the drive wheel, the drive lugs registering with respective ones of
the
traction projections in a longitudinal direction of the endless track, the
endless

30
track being free of stiffening rods extending transversally of the endless
track at
locations at which a drive lug registers with a traction projection.
75)A track assembly as defined in any one of claims 61 to 74, wherein the
drive
wheel has a periphery bound between a first upper horizontal imaginary plane
and a first lower horizontal imaginary plane, the leading idler wheel having a
periphery bound between a second upper horizontal imaginary plane and a
second lower horizontal imaginary plane, the trailing idler wheel having a
periphery bound between a third upper horizontal imaginary plane and a third
lower horizontal imaginary plane, the first lower horizontal imaginary plane
being
positioned below the second upper horizontal imaginary plane and below the
third upper horizontal imaginary plane.
76)A track assembly as defined in any one of claims 61 to 75, wherein the
plurality
of wheels imparts a generally triangular path of travel to the endless track.
77)A track assembly as defined in any one of claims 61 to 76, wherein the
drive
wheel has an extent along an axis of rotation of the drive wheel that is less
than a
transverse dimension of the endless track.
78)A track assembly as defined in any one of claims 61 to 77, wherein the
track
assembly is steerable by a steering mechanism of the AW to change an
orientation of the track assembly in order to steer the ATV.
79)A set of track assemblies for providing traction to an all-terrain vehicle
(ATV),
wherein at least two of the track assemblies are as defined in any one of
claims
61 to 78.
80)An all-terrain vehicle (ATV) comprising a track assembly as defined in any
one of
claims 61 to 78.

31
81)An all-terrain vehicle (A-N) comprising a track assembly as defined in
claim 78,
wherein the steering mechanism of the ATV comprises handlebars.
82)An all-terrain vehicle (ATV) comprising a set of track assemblies as
defined in
claim 79.
83)An ATV as defined in claim 81, wherein the steering mechanism includes a
rod
coupled to the track assembly for controlling an angular orientation of the
track
assembly.
84)A track assembly for providing traction to a vehicle, the track assembly
comprising:
a) a plurality of wheels which includes:
- a drive wheel; and
- a leading idler wheel and a trailing idler wheel;
an axis of rotation of the drive wheel being located between an axis of
rotation
of the leading idler wheel and an axis of rotation of the trailing idler wheel
in a
longitudinal direction of the track assembly, the drive wheel overlapping with
a
given one of the leading idler wheel and the trailing idler wheel when viewed
in a direction parallel to the axis of rotation of the drive wheel; and
b) a track disposed around the wheels, the track comprising flexible material
to
flex around the wheels, the track comprising:
- an inner surface for facing the wheels;
- a ground-engaging outer surface opposite to the inner surface;
- a plurality of traction projections projecting from the ground-
engaging
outer surface and distributed in a longitudinal direction of the track;
a bottom run of the track extending under the leading idler wheel and the
trailing idler wheel, the bottom run of the track comprising:

32
- an intermediate section located between the leading idler wheel and
the trailing idler wheel;
- a leading section rising from the intermediate section and extending
towards the leading idler wheel; and
- a trailing section rising from the intermediate section and extending
towards the trailing idler wheel.
85)A track assembly as defined in claim 84, wherein the given one of the
leading
idler wheel and the trailing idler wheel is the trailing idler wheel.
86)A track assembly as defined in any one of claims 84 and 85, wherein a
distance
between the axis of rotation of the drive wheel and the axis of rotation of
the
leading idler wheel in the longitudinal direction of the track assembly is
different
from a distance between the axis of rotation of the drive wheel and an axis of
rotation of the trailing idler wheel in the longitudinal direction of the
track
assembly.
87)A track assembly as defined in claim 86, wherein the distance between the
axis
of rotation of the drive wheel and the axis of rotation of the leading idler
wheel in
the longitudinal direction of the track assembly is greater than the distance
between the axis of rotation of the drive wheel and the axis of rotation of
the
trailing idler wheel in the longitudinal direction of the track assembly.
88)A track assembly as defined in any one of claims 84 to 87, comprising a
support
structure supporting the leading idler wheel and the trailing idler wheel and
comprising a first arm extending downwardly and forwardly towards the leading
idler wheel and a second arm extending downwardly and rearwardly towards the
trailing idler wheel.

33
89)A track assembly as defined in claim 88, wherein the first arm is longer
than the
second arm.
90)A track assembly as defined in any one of claims 84 to 89, wherein the
drive
wheel engages the bottom run of the track.
91)A track assembly as defined in any one of claims 84 to 90, wherein the
endless
track is free of stiffening members extending transversally to the
longitudinal
direction of the track.
92)A track assembly as defined in any one of claims 84 to 91, wherein a
profile of
the track in a transversal direction of the track is generally convex.
93)A track assembly as defined in any one of claims 84 to 92, wherein the
track
comprises a plurality of drive lugs projecting from the inner surface for
engaging
the drive wheel.
94) A track assembly as defined in any one of claims 84 to 90, wherein the
track has
a pair of lateral edge portions and a central portion between the lateral edge
portions, the lateral edge portions being free of stiffening members extending
transversally to the longitudinal direction of the track.
95)A track assembly as defined in claim 94, wherein the central portion
includes one
or more stiffening rods extending transversally to the longitudinal direction
of the
track and shorter than a transverse dimension of the track.
96)A track assembly as defined in any one of claims 84 to 90, wherein the
track is
free of stiffening members at locations of respective ones of the traction
projections in the longitudinal direction of the track.

34
97)A track assembly as defined in any one of claims 84 to 90, wherein the
track
comprises a plurality of drive lugs projecting from the inner surface for
engaging
the drive wheel, the drive lugs registering with respective ones of the
traction
projections in the longitudinal direction of the track, the track being free
of
stiffening members extending transversally of the track at locations at which
a
drive lug registers with a traction projection.
98)A track assembly as defined in any one of claims 84 to 97, wherein the
drive
wheel has an extent along the axis of rotation of the drive wheel that is less
than
a transverse dimension of the track.
99)A track assembly as defined in any one of claims 84 to 98, wherein an
extent of
the intermediate section of the bottom run of the track in the longitudinal
direction
of the track assembly does not exceed a diameter of the drive wheel.
100) A track assembly as defined in claim 99, wherein the extent of the
intermediate section of the bottom run of the track in the longitudinal
direction of
the track assembly does not exceed a radius of the drive wheel.
101) A track assembly as defined in any one of claims 84 to 100, wherein the
track
assembly is steerable by a steering mechanism of the vehicle to change an
orientation of the track assembly in order to steer the vehicle.
102) A track assembly as defined in any one of claims 84 to 101, wherein the
vehicle is an all-terrain vehicle (ATV).
103) A track assembly as defined in claim 102, wherein the ATV comprises a
straddle seat and handlebars.

35
104) A set of track assemblies for providing traction to a vehicle, wherein at
least
two of the track assemblies are as defined in any one of claims 84 to 103.
105) A vehicle comprising a track assembly as defined in any one of claims 84
to
101.
106) A vehicle as defined in claim 105, wherein the vehicle is an all-terrain
vehicle
(ATV).
107) A vehicle as defined in claim 106, wherein the ATV comprises a straddle
seat
and handlebars.
108) A vehicle comprising a set of track assemblies as defined in claim 104.
109) A vehicle as defined in claim 108, wherein the vehicle is an all-terrain
vehicle
(ATV).
110) A vehicle as defined in claim 109, wherein the ATV comprises a straddle
seat
and handlebars.
111) A track assembly for providing traction to a vehicle, the track assembly
comprising:
a) a plurality of wheels which includes:
- a drive wheel; and
- a leading idler wheel and a trailing idler wheel;
an axis of rotation of the drive wheel being located between an axis of
rotation
of the leading idler wheel and an axis of rotation of the trailing idler wheel
in a
longitudinal direction of the track assembly, a distance between the axis of
rotation of the drive wheel and the axis of rotation of the leading idler
wheel in
the longitudinal direction of the track assembly being different from a
distance

36
between the axis of rotation of the drive wheel and the axis of rotation of
the
trailing idler wheel in the longitudinal direction of the track assembly, the
drive
wheel overlapping with a given one of the leading idler wheel and the trailing
idler wheel when viewed in a direction parallel to the axis of rotation of the
drive wheel; and
b) a track disposed around the wheels, the track comprising flexible material
to
flex around the wheels, the track comprising:
- an inner surface for facing the wheels;
a ground-engaging outer surface opposite to the inner surface;
- a plurality of traction projections projecting from the ground-engaging
outer surface and distributed in a longitudinal direction of the track;
a bottom run of the track extending under the leading idler wheel and the
trailing idler wheel.
112) A track assembly as defined in claim 111, wherein the given one of the
leading idler wheel and the trailing idler wheel is the trailing idler wheel.
113) A track assembly as defined in any one of claims 111 and 112, wherein the
distance between the axis of rotation of the drive wheel and the axis of
rotation of
the leading idler wheel in the longitudinal direction of the track assembly is
greater than the distance between the axis of rotation of the drive wheel and
the
axis of rotation of the trailing idler wheel in the longitudinal direction of
the track
assembly.
114) A track assembly as defined in any one of claims 111 to 113, comprising a
support structure supporting the leading idler wheel and the trailing idler
wheel
and comprising a first arm extending downwardly and forwardly towards the
leading idler wheel and a second arm extending downwardly and rearwardly
towards the trailing idler wheel.

37
115) A track assembly as defined in claim 114, wherein the first arm is longer
than
the second arm.
116) A track assembly as defined in any one of claims 111 to 115, wherein the
drive wheel engages the bottom run of the track.
117) A track assembly as defined in any one of claims 111 to 116, wherein the
endless track is free of stiffening members extending transversally to the
longitudinal direction of the track.
118) A track assembly as defined in any one of claims 111 to 117, wherein a
profile of the track in a transversal direction of the track is generally
convex.
119) A track assembly as defined in any one of claims 111 to 118, wherein the
track comprises a plurality of drive lugs projecting from the inner surface
for
engaging the drive wheel.
120) A track assembly as defined in any one of claims 111 to 116, wherein the
track has a pair of lateral edge portions and a central portion between the
lateral
edge portions, the lateral edge portions being free of stiffening members
extending transversally to the longitudinal direction of the track.
121) A track assembly as defined in claim 120, wherein the central portion
includes
one or more stiffening rods extending transversally to the longitudinal
direction of
the track and shorter than a transverse dimension of the track.
122) A track assembly as defined in any one of claims 111 to 116, wherein the
track is free of stiffening members at locations of respective ones of the
traction
projections in the longitudinal direction of the track.

38
123) A track assembly as defined in any one of claims 111 to 116, wherein the
track comprises a plurality of drive lugs projecting from the inner surface
for
engaging the drive wheel, the drive lugs registering with respective ones of
the
traction projections in the longitudinal direction of the track, the track
being free of
stiffening members extending transversally of the track at locations at which
a
drive lug registers with a traction projection.
124) A track assembly as defined in any one of claims 111 to 123, wherein the
drive wheel has an extent along the axis of rotation of the drive wheel that
is less
than a transverse dimension of the track.
125) A track assembly as defined in any one of claims 111 to 124, wherein the
bottom run of the track comprises an intermediate section located between the
leading idler wheel and the trailing idler wheel, a leading section rising
from the
intermediate section and extending towards the leading idler wheel, and a
trailing
section rising from the intermediate section and extending towards the
trailing
idler wheel.
126) A track assembly as defined in claim 125, wherein an extent of the
intermediate section of the bottom run of the track in the longitudinal
direction of
the track assembly does not exceed a diameter of the drive wheel.
127) A track assembly as defined in claim 126, wherein the extent of the
intermediate section of the bottom run of the track in the longitudinal
direction of
the track assembly does not exceed a radius of the drive wheel.
128) A track assembly as defined in any one of claims 111 to 127, wherein the
track assembly is steerable by a steering mechanism of the vehicle to change
an
orientation of the track assembly in order to steer the vehicle.

39
129) A track assembly as defined in any one of claims 111 to 128, wherein the
vehicle is an all-terrain vehicle (ATV).
130) A track assembly as defined in claim 129, wherein the ATV comprises a
straddle seat and handlebars.
131) A set of track assemblies for providing traction to a vehicle, wherein at
least
two of the track assemblies are as defined in any one of claims 111 to 128.
132) A vehicle comprising a track assembly as defined in any one of claims 111
to
128.
133) A vehicle as defined in claim 132, wherein the vehicle is an all-terrain
vehicle
(ATV).
134) A vehicle as defined in claim 133, wherein the ATV comprises a straddle
seat
and handlebars.
135) A vehicle comprising a set of track assemblies as defined in claim 131.
136) A vehicle as defined in claim 135, wherein the vehicle is an all-terrain
vehicle
(ATV).
137) A vehicle as defined in claim 136, wherein the ATV comprises a straddle
seat
and handlebars.

Description

CA 02854554 2014-06-16
1
TITLE OF THE INVENTION
Track assembly for an all-terrain vehicle
FIELD OF THE INVENTION
[0001] The present invention relates to all-terrain vehicles. More
specifically, the present invention is concerned with track assemblies for an
all-
terrain vehicle.
BACKGROUND OF THE INVENTION
[0002] Traditionally, two types of all-terrain vehicles are proposed
either the wheel type or the tracked type.
[0003] Generally, a wheeled vehicle is more maneuverable than a
tracked vehicle, but is not as efficient on uneven or soft terrain such as,
for
example snow.
[0004] Tracked all-terrain vehicles have been proposed, which
require complicated track assemblies comprising a track frame to maintain the
tension of the endless track belt and prevent it from loosening. Furthermore,
such vehicles have generally a large contact area with the ground, which
results in a decreased maneuverability and an increased impact on the often
soft terrain.
[0005] Therefore, there is still room for improvements toward an all-
terrain vehicle provided with track assemblies, which is maneuverable and
effective upon a variety of unstable or uneven surfaces, while designed to
maintain tension upon the endless track belts to keep them in their due course

CA 02854554 2014-06-16
2a
and prevent accidental loosening, and at the same time reducing damages
inflicted
on the terrain.
OBJECTS OF THE INVENTION
[0006] An object of the present invention is therefore to provide improved
track assemblies for an all-terrain vehicle.
SUMMARY OF THE INVENTION
[0006A] In accordance with an aspect of the present invention, there is
provided a track assembly for a reduced-size vehicle designed primarily for
off-
highway usage, over undeveloped roads or other unprepared surfaces. The track
assembly has a leading end and a trailing end. The track assembly comprises:
an
endless track having an outer ground engaging surface and an opposite inner
surface; and a plurality of wheels for supporting and driving the endless
track. The
plurality of wheels includes: a leading idler, a trailing idler and a drive
wheel. The
leading and trailing idlers are in a spaced apart relationship. A segment of
the
endless track extending between the leading and trailing idlers defines a
ground
engaging run. The leading idler has a first axis of rotation and the trailing
idler has a
second axis of rotation. The drive wheel has a third axis of rotation. The
drive wheel
is in driving engagement with the endless track for imparting movement to the
endless track. The drive wheel overlaps with one of the leading idler and the
trailing
idler when viewed in a plane normal to the third axis of rotation.
[0006B] In accordance with another aspect of the present invention, there
is
provided a track assembly for a reduced-size vehicle designed primarily for
off-
highway usage, over undeveloped roads or other unprepared surfaces. The track
assembly comprises: an endless track having an outer ground engaging surface
and
an opposite inner surface; and a plurality of wheels for supporting and
driving the

CA 02854554 2014-06-16
2b
endless track. The plurality of wheels includes: an idler having a first axis
of rotation;
and a drive wheel having a second axis of rotation. The drive wheel is in
driving
engagement with the endless track for imparting movement to the endless track.
The
sum of a radius of the idler and a radius of the drive wheel exceeds a
distance
between the first axis of rotation and the second axis of rotation.
[0006C] In accordance with another aspect of the present invention, there
is
provided a track assembly for providing traction to an all-terrain vehicle
(ATV). The
track assembly is configured to replace a ground-engaging wheel of the ATV.
The
track assembly comprises a plurality of wheels and an endless track disposed
around the plurality of wheels. The plurality of wheels includes: a drive
wheel, and a
leading idler wheel and a trailing idler wheel spaced apart from the leading
idler
wheel in a longitudinal direction of the track assembly. The drive wheel and a
given
one of the leading idler wheel and the trailing idler wheel overlap in the
longitudinal
direction of the track assembly. The endless track comprises: an inner surface
for
facing the plurality of wheels, the drive wheel being rotatable to impart
motion to the
endless track; a ground-engaging outer surface opposite to the inner surface;
and a
plurality of traction projections projecting from the ground-engaging outer
surface.
[0006D] In accordance with another aspect of the present invention, there
is
provided a track assembly for providing traction to an all-terrain vehicle
(ATV). The
track assembly is configured to replace a ground-engaging wheel of the ATV.
The
track assembly comprises a plurality of wheels and an endless track disposed
around the plurality of wheels. The plurality of wheels includes: a drive
wheel; and a
leading idler wheel and a trailing idler wheel spaced apart from the leading
idler
wheel in a longitudinal direction of the track assembly. A sum of a radius of
the drive
wheel and a radius of a given one of the leading idler wheel and the trailing
idler
wheel is greater than a distance in the longitudinal direction of the track
assembly
between an axis of rotation of the drive wheel and an axis of rotation of the
given
one of the leading idler wheel and the trailing idler wheel. The endless track

CA 02854554 2015-06-10
2c
comprises: an inner surface for facing the plurality of wheels, the drive
wheel being
rotatable to impart motion of the endless track; a ground-engaging outer
surface
opposite to the inner surface; and a plurality of traction projections
projecting from
the ground-engaging outer surface.
[0006E] In accordance with another aspect of the present invention, there
is
provided a track assembly for a reduced-size vehicle designed primarily for
off-
highway usage, over undeveloped roads or other unprepared surfaces. The track
assembly comprises a plurality of wheels and an endless track disposed around
the
plurality of wheels. The plurality of wheels includes: a drive wheel; and a
leading
idler wheel and a trailing idler wheel spaced apart from the leading idler
wheel in a
longitudinal direction of the track assembly. The bottom of the drive wheel is
positioned below a top of a given one of the leading idler wheel and the
trailing idler
wheel. The endless track comprises: an inner surface for facing the plurality
of
wheels, the drive wheel being rotatable to impart motion of the endless track;
a
ground-engaging outer surface opposite to the inner surface; and a plurality
of
traction projections projecting from the ground-engaging outer surface.
[0006F] In accordance with yet another aspect of the invention, there is
provided a track assembly for providing traction to a vehicle. The track
assembly
comprises a plurality of wheels which includes a drive wheel, a leading idler
wheel,
and a trailing idler wheel. An axis of rotation of the drive wheel is located
between an
axis of rotation of the leading idler wheel and an axis of rotation of the
trailing idler
wheel in a longitudinal direction of the track assembly. The drive wheel
overlaps with
a given one of the leading idler wheel and the trailing idler wheel when
viewed in a
direction parallel to the axis of rotation of the drive wheel. The track
assembly
comprises a track disposed around the wheels. The track comprises flexible
material
to flex around the wheels. The track comprises an inner surface for facing the
wheels, a ground-engaging outer surface opposite to the inner surface, and a
plurality of traction projections projecting from the ground-engaging outer
surface

CA 02854554 2015-06-10
2d
and distributed in a longitudinal direction of the track. A bottom run of the
track
extends under the leading idler wheel and the trailing idler wheel. The bottom
run of
the track comprises an intermediate section located between the leading idler
wheel
and the trailing idler wheel; a leading section rising from the intermediate
section and
extending towards the leading idler wheel; and a trailing section rising from
the
intermediate section and extending towards the trailing idler wheel.
[0006G] In accordance with a further aspect of the invention, there is
provided a
track assembly for providing traction to a vehicle. The track assembly
comprises a
plurality of wheels which includes a drive wheel, a leading idler wheel, and a
trailing
idler wheel. An axis of rotation of the drive wheel is located between an axis
of
rotation of the leading idler wheel and an axis of rotation of the trailing
idler wheel in
a longitudinal direction of the track assembly. A distance between the axis of
rotation
of the drive wheel and the axis of rotation of the leading idler wheel in the
longitudinal direction of the track assembly is different from a distance
between the
axis of rotation of the drive wheel and the axis of rotation of the trailing
idler wheel in
the longitudinal direction of the track assembly. The drive wheel overlaps
with a
given one of the leading idler wheel and the trailing idler wheel when viewed
in a
direction parallel to the axis of rotation of the drive wheel. The track
assembly
comprises a track disposed around the wheels. The track comprises flexible
material
to flex around the wheels. The track comprises an inner surface for facing the
wheels, a ground-engaging outer surface opposite to the inner surface, and a
plurality of traction projections projecting from the ground-engaging outer
surface
and distributed in a longitudinal direction of the track. A bottom run of the
track
extends under the leading idler wheel and the trailing idler wheel.
[0007] In accordance with another aspect of the present invention, there
is
provided an all-terrain vehicle comprising at least two track assemblies to
support
the ail-terrain vehicle onto a ground surface, each one of said at least two
track
assemblies comprising: a longitudinal endless track belt provided with an
inner

CA 02854554 2015-06-10
2e
surface provided with a plurality of inner lugs and an outer surface provided
with a
plurality of external lugs; a mounting structure to mount said longitudinal
endless
track belt to said vehicle, wherein, when mounted to said mounting structure,
said
longitudinal endless track belt has a punctually localized surface contact
with the
ground surface.
[0008] In
accordance with another aspect of the present invention, there is
provided an endless track belt assembly comprising: a track driving wheel
provided

CA 02854554 2014-06-16
3
with a plurality of teeth; an endless track belt provided with an inner
surface having
a plurality of inner lugs and an outer surface having a plurality of external
lugs, said
endless track belt being wounded around said track driving wheel; wherein a)
said
teeth are so spaced that a distance between two consecutive teeth spans a
distance
separating two consecutive inner lugs of said endless track belt and b) said
endless
track belt, when mounted to said track driving wheel, has a punctually
localized
contact with a ground surface.
[0009] In accordance with another aspect of the present invention, there is
provided a method for mounting an endless track belt on a all-terrain vehicle,
comprising the acts of: providing an endless track belt having inner lugs and
external
lugs; providing a track driving wheel having a plurality of teeth so spaced
that a
distance between two consecutive of the plurality of teeth spans a distance
separating two consecutive of a plurality of inner lugs of the endless track
belt;
interconnecting the track driving wheel to an inside idler wheel and to an
outside
idler wheel; and tensioning the endless track belt around the track driving
wheel, the
inside idler wheel and the outside idler wheel so that the endless track belt
has a
punctually localized surface contact with a ground surface.
[0010] Other objects, advantages and features of the present invention will
become more apparent upon reading of the following nonrestrictive description
of
preferred embodiments thereof, given by way of example only with reference to
the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the appended drawings:

CA 02854554 2014-06-16
4
[0012] Figure 1 is a side elevational view of an all-terrain vehicle
provided with track assemblies according to an embodiment of the present
invention;
[0013] Figure 2 is a side elevational view of the front track assembly
of the vehicle of Figure 1, seen from of the outside of the all-terrain
vehicle;
[0014] Figure 3 is a side elevational view of the front track assembly
of the vehicle of Figure 1, seen form the inside of the all-terrain vehicle;
[0015] Figure 4 is a sectional view taken along the line 4-4 of Figure
3;
[0016] Figure 5 is an enlarged side view of an outside idler wheel
attachment of the track assembly of Figure 2;
[0017] Figure 6 is a sectional view of a rigid member of the track
assembly of Figure 2;
[0018] Figure 7 is a top plan view of the attachment of the front track
assembly of Figure 1 to the all-terrain vehicle;
[0019] Figure 8 is a side elevational view of a rear track assembly of
Figure 1, seen from the inside of the all-terrain vehicle;
[0020] Figure 9 is a top plan view of the attachment of the rear track
assembly of Figure 1 to the all-terrain vehicle;

CA 02854554 2014-06-16
[0021] Figure 10 is a sectional view similar to Figure 4 but
illustrating
a second type of endless track; and
[0022] Figure 11 is a sectional view similar to Figure 4 but
illustrating
a third type of endless track.
DESCRIPTION OF THE EMBODIMENT
[0023] A track assembly for an all-terrain vehicle according to an
embodiment of the present invention will now be described in details with
reference to the appended drawings.
[0024] Figure 1 shows an all-terrain vehicle 10 comprising a body 12
and four track assemblies (only two shown) according to the present invention
arranged in a plane adjacent to each side of the vehicle 10.
[0025] There are two identical track assemblies in the front of the all-
terrain vehicle 10, of which only one track assembly 14 is visible in Figure
1, in
place of conventional front wheels. Similarly, there are two identical track
assemblies, of which only one track assembly 16 is visible in Figure 1, in
place
of the conventional rear wheels.
[0026] Only the track assemblies 14 and 16 visible in Figure 1 will be
described hereinbelow. Furthermore, as they are symmetrical about a vertical
axis 22 when viewed from the outside of the vehicle 10 (see Figure 1), only
the
track assemblies 14 will be described hereinbelow. It is also to be noted that
the elements as seen from the outside of the vehicle 10 will bear the same

CA 02854554 2014-06-16
6
numbers in the rear track assembly 16 than the corresponding ones in the front
track assembly 14, with a prime.
[0027] However, since the
attachment of rear and front track
assemblies differs as seen from the inside of the vehicles 10, they will be
described separately.
[0028] The front track
assembly 14 is better seen in Figure 2. It
comprises a longitudinal endless track belt 23 and a mounting structure to
mount the endless track belt 23 to the vehicle 10. The mounting structure
includes a track driving wheel 24, a pair of inside idler wheels 26, a pair of
outside idler wheels 28 and supports to interconnect the wheels 24, 26 and 28
as will be described hereinbelow.
[0029] The endless track
belt 23 is provided with inner lugs 30 on its
inner surface 31 and with external lugs 32 on its outer surface 33. It is
wounded
around the track driving wheel 24 and the idler wheels 28 and 26.
[0030] As can be better
seen from Figure 4, the track driving wheel
24 is mounted to a conventional hub 35 of the all-terrain vehicle 10. The
wheel
24 includes a first mounting plate 37 mounted to the hub 35 and a second
mounting plate 34 mounted to the first plate 37 via four bolt and spacer
assemblies 36. A circular disk 38 is mounted to the bolt and spacer assemblies
36 and includes equidistant wide teeth 40 contacting the inner surface 31 of
the
track 23.
[0031] As will be
apparent to one skilled in the art, the equidistant
teeth 40 are so located as to cooperate with some of the inner lugs 30 of the
endless track belt 23. More precisely, as can be better seen from Figure 2,
the

CA 02854554 2014-06-16
7
teeth 40 are spaced so that the distance between two consecutive teeth 40
spans the distance separating consecutive inner lugs 30 of the endless track
belt 23, in a meshing engagement, in such a way as to drive the endless track
belt 23.
[0032] Each of the inside idler wheels 26 includes a peripheral
portion in contact with the internal surface 31 of the track 23. The wheels 26
are interconnected by a spacing element (not shown).
[0033] Similarly, each outer idler wheel 28 includes a peripheral
portion in contact with the internal surface 31 of the track 23. The wheels 28
are interconnected by a spacing element 42.
[0034] The wheels 24, 26 and 28 are interconnected, as seen from
the outside of the track assembly 14, by an angled connecting element 44. The
angled connecting element 44 has a center portion 46 provided with an
aperture 48 in which bearings 50 are mounted. A fastener 52 connects the
connecting element 44 to the second plate 34 while allowing the angled
connecting element 44 to pivot about the fastener.
[0035] The connecting element 44 has a short arm 54 having a free
end to which the inside idler wheels 26 are rotatably mounted. The connecting
element 44 also has a long arm 56 having a free end to which the inside idler
wheels 28 are rotatably mounted as will be further discussed hereinbelow. The
connecting element 44 is better seen from the top plan view of Figure 6.
[0036] Turning now briefly to Figure 3 of the appended drawings, as
can be seen from the inside of the all-terrain vehicle 10, the idler wheels 26
and
28 of the front track assembly 14 are also directly connected together by an

CA 02854554 2014-06-16
8
elbowed connection element 58. The inside idler wheels 26 are rotatably
mounted to a first end of the elbowed connection element 58 while the outside
idler wheels 28 are rotatably mounted to a second end of the elbowed
connection element 58.
[0037] The rotatable connection of the outside idler wheels 28 to the
angle connection element 44 and to the elbowed connection element 58 will
now be described with reference to Figure 5.
[0038] As will easily be understood by one skilled in the art upon
inspection of Figure 5, the tension of the endless track belt 23 is adjusted
by
the connection of the outside idler wheels 28 to the elements 44 and 58. For
concision purpose, only the connection of the wheels 28 to the elbowed
connection element 58 will be described.
[0039] With reference to the enlarged side view of Figure 5, a
tension adjusting assembly according to another aspect of the present
invention will be described. As can be seen from this figure, a distal end of
the
connection element 58 includes a slotted aperture 60 receiving a fastener 62
used to rotatably mount the wheels 28 to the assembly. By sliding the fastener
62 in the aperture 60, it is possible to increase or decrease the tension on
the
track 23. To adjust and maintain this track tension, a cam element 64, having
an outer periphery provided with notches 66 located at different distances
from
the attachment point of the element 64, is mounted to the fastener 62. By
selecting which notch 66 is in contact with a fixed pin 68 of the element 58,
a
predetermined tension may be maintained. It is to be noted that the cam
element 64 is provided with a handle 70 to facilitate the manipulation by a
user.

CA 02854554 2014-06-16
9
[0040] Returning to Figure 4 of the appended drawings the endless
track 23 will be described in greater detail.
[0041] As can be seen from Figure 4, the overall profile of the track
23, from one side to the other, i.e. transversely, is generally convex.
However,
the convex profile of the track 23 is created by a lug arrangement comprising
two successive transverse rows of lugs arranged in a staggered relationship.
[0042] A first transverse row of lugs contains three lugs 72, 74 and
76 and a second row of lugs contains four lugs 78, 80, 82 and 84. These lugs
are symmetrical about a longitudinal axis (not shown).
[0043] A first lateral lug 72 of the first row includes three ground-
contacting surfaces separated by two indentations. The shape of lateral lug 72
is such that the ground contacting surfaces are generally transversally
convex.
[0044] A central lug 74 is centered about longitudinal axis and
includes two ground-contacting surfaces separated by an indentation. The
ground contacting surfaces are symmetrical about the longitudinal axis and are
generally transversally convex.
[0045] A second lateral lug 76 is a mirror image of lug 72 about the
longitudinal axis.
[0046] The first and second lateral lugs 72 and 76 are laterally
spaced apart from the central lug 74.

CA 02854554 2014-06-16
[0047] In the second transverse row of lugs, a first intermediate lug
80 includes two ground-contacting surfaces separated by an indentation. The
ground engaging surfaces are slightly transversally convex.
[0048] A first external lug 78 includes two ground-contacting
surfaces that are separated by an indentation and are transversally convex.
[0049] Finally, the second intermediate lug 82 and the second
external lug 84 are respectively mirror images of lugs 80 and 78 with respect
to
the longitudinal axis. For concision purposes, these lugs will not be further
described herein.
[0050] Of course, the sequences described hereinabove of the lug
arrangement defined by the rows of lugs are repeated onto the entire external
surface of the endless track 23.
[0051] The endless track belt 23 further includes, for each row of
lugs, a stiffening rod 71, made of glass fibers for example. Each stiffening
rod
71 is embedded in the material forming the track belt 23 so as to be generally
parallel to the inner surface 31 thereof. The rods 71 provide enhanced
rigidity
to the endless track belt 23. The enhanced rigidity of the track belt 23 has
many
advantages. For example, it helps the track to provide adequate traction even
when the center portion of the track is not in direct contact with the ground,
as
illustrated in Figure 4. However, it has been found that this type of traction
may
be detrimental to the steering of the vehicle in some conditions.
[0052] As it is apparent from Figure 4 the ground contacting surfaces
of symmetrical lugs 78 and 84 are not aligned with the outer surfaces of the
other lugs to form a continuous profile. Indeed, the ground contacting
surfaces

CA 02854554 2014-06-16
11
of lugs 78 and 84 are more angled and exceed the convex profile defined by
the other lugs. This configuration of the outer lugs is advantageous since it
further prevents the vehicle from tipping over during sharp turns at high
speed
when the vehicle 10 is severely tilted.
[0053] As mentioned hereinabove, the way the front track assembly
14 is attached to the body 12 of the vehicle 10 differs from the way the rear
track assembly 16 is attached to the body 12 of the vehicle 10. These two
attachments will be described hereinbelow.
[0054] The front track assembly 14 is attached to the body 12 of the
vehicle 10 in a fashion shown in Figures 4 and 7, while the rear track
assembly
16 is attached to the body 12 of the vehicle 10 in a fashion shown in Figure 8
and 9.
[0055] As seen in Figures 4 and 7, the front track assembly 14 is
mounted to a tubular wheel table 100 of the vehicle 10 by means of a generally
triangular plate 102 fastened thereto by a plurality of U-bolts 104, 106, 108
and
110. A rod 112 is connected between the elbowed connection element 58 and
a pivot 114 of the tubular wheel table 100. A first end of the rod 112 is
attached
to the elbowed connection element 58 by means of rubber damping elements
116, in such a way as to allow a vertical movement at this point of the rod
112
in relation to the elbowed connection element 58. A second end of the rod 112
is attached to the pivot 114 of the tubular wheel table 100 by means of an R-
clip 120, in such a way as to allow at this point a horizontal movement of the
plate 102 holding the tubular wheel table 100 relative to the elbowed
connection element 58.

CA 02854554 2014-06-16
12
[0056] The front track assembly 14 is further attached to the body 12
of the vehicle 10 through a conventional rod 150 of the suspension system of
the vehicle 10 and a conventional rod 157 used for direction (see Figure 4).
[0057] As seen in Figures 8 and 9, the rear track assembly 16 is
mounted to the body 12 of the vehicle 10 by a rod 212. The rod 212 is
connected on a first end to the elbowed connection element 58' by means of a
rubber damping attachment 216. It is attached, on a second end, to a tubular
chassis 130 of the body 12 of the vehicle 10 by means of a chipping joint 132
fastened thereto by an R-clip 134.
[0058] From the above description of the fashion in which the front
and rear track assemblies 14 and 16 are mounted to the body 12 of the vehicle
10, in relation to Figures 4 and 7, and 8 and 9 respectively, the present
invention provides for track assemblies that are easily removed or mounted to
the vehicle 10, through using R-clips (120 and 134), which enable
disconnecting the track assemblies from the vehicle in a simple manner.
[0059] As stated hereinabove, the interior surface 31 of the endless
track belt 23 is provided with a plurality of equally spaced lugs 30, which
ensure
a positive engagement with the teeth 40 provided on the outer circumference of
the wheel 24. In operation, the wheel 24 is coupled to a drive shaft, via the
hub
30, connected to an engine (not shown), in such a way that the engine drives
the wheel 24 in rotation. The wheel 24 thus drives the endless track belt 23
by
the meshing engagement of the teeth 40 with the internal lugs 30 of the
endless track belt 23.
[0060] It is further to be understood that the external lugs 32 on the
external circumference surface of the endless track belt 23 respectively exert
a

CA 02854554 2014-06-16
13
positive mechanical connection with the underlying ground surface that
contributes to propel the vehicle 10.
[0061] Figure 10 and Figure 11 show sectional views similar to that
of Figure 4 but illustrating variants of an endless track that may be mounted
to
the track assembly of the present invention.
[0062] In Figure 10, the overall profile of the endless track belt 23a,
from one side to the other, i.e. transversely, is generally convex.
[0063] The convex profile of the endless track belt 23a is created by
the same lug arrangement as that described hereinabove in relation to Figure
4. In this specific embodiment however, the endless track belt 23a does not
include stiffening rods under each row of lugs. Consequently, the rigidity of
the
endless track belt 23a is less than the rigidity of the endless track belt 23
(Figure 4) and the profile of the endless track belt 23a conforms itself to
the
profile of the ground. Since the pressure is more localized in the center of
the
endless track belt 23a, a more punctually localized contact zone between the
endless track belt 23a and the ground 29 is created. In many cases, this
punctually localized contact zone makes the vehicle 10 more maneuverable.
[0064] Turning now to Figure 11, a third version of an endless track
belt 23b will be described. The endless track belt 23b is wounded around the
track driving wheel 24 and the idler wheels 28 and 26, is still provided with
inner lugs 30 on its inner surface 31. However, its outer surface is provided
with
rectangular lugs 86. Since there are no stiffening rods in the endless track
belt
23b, the endless track belt 23b is free to conform itself to the ground 29, as
seen in Figure 11. Furthermore, since the pressure is exerted only in the
middle

CA 02854554 2014-10-14
14
of the endless track belt 23b by the wide teeth 40, a punctually localized
contact
zone between the endless track belt 23b and the ground 29 is created.
[0065] As will be apparent to one skilled in the art, the endless track
belts 23a
has a particularly punctually localized contact surface with the ground 29.
Indeed,
since it is transversally convex, it generally contacts the ground 29 with a
limited
surface at any given time when the ground 29 is hard.
[0066] Furthermore, since there are no guiding rails for the endless track
belts
23, 23a or 23b, the external lugs only exert a pressure on the ground 29, when
it is
hard, in the vicinity of the wide teeth 40 of the wheel 24. These two combined
features improve the maneuverability of the vehicle since it emulates the
contact of a
conventional tire onto hard ground, given that a shortened length of contact
of the
endless track with the ground surface reduces the resistance to a turning
force.
[0067] Of course, one skilled in the art could design another convex
profile of
the external lugs of the endless track belts 23 and/or another arrangement of
the
mounting assembly of the endless track belts 23 to the vehicle 10 to obtain
this "one
point contact" feature. For example, one could provide a guiding rail having a
convex
profile and transversally convex lugs to achieve similar results.
[0068] As people in the art will understand, the all-terrain vehicle of
the
present invention, provided with four endless track assemblies, can be used
for a
wide range of operations and terrain, while being highly mobile and offering
good
running performance.

CA 02854554 2014-10-14
[0069] The endless track structure maintains an adequate configuration
over
a variety of surfaces.
[0070] It will be obvious to people skilled in the art that the present
invention
can be applied both in the case of a two-wheel drive vehicle wherein the power
is
typically applied only to the rear track belt assemblies and the front track
assemblies
merely facilitate steering, and in the case of a four-wheel vehicle, wherein
power is
independently provided to each one of the four track assemblies.
[0071] As will be further understood by one skilled in the art, the all-
terrain
vehicle 10, equipped with track assemblies according to the present invention,
may
be viewed as a snow vehicle since it may be used on snow as efficiently as
conventional snow vehicles such as snowmobiles, for example. However, the one-
point contact feature of the present invention allows the use of the all-
terrain vehicle
on harder surface without the usual drawbacks of tracked vehicles.
[0072] Interestingly, the present track assembly system can equip all four
wheels of an all-terrain vehicle or only the front or rear wheels thereof,
since it only
weakly reduces the speed of the vehicle relative to the underground surface.
[0073] A further possibility would be to use track assemblies according to
the
present invention in place of the rear wheels of a vehicle, while mounting
skis in
place of the front wheels thereof.
[0074] Although the present invention has been described hereinabove by
way of preferred embodiments thereof, it can be modified,

CA 02854554 2014-10-14
16
and remain within the scope of the invention as defined in the appended
claims.

Dessin représentatif