Note: Claims are shown in the official language in which they were submitted.
19
CLAIMS:
1. A track assembly for a reduced-size vehicle designed primarily for off-
highway usage, over undeveloped roads or other unprepared surfaces, steerable
by
changing an orientation of the track assembly by a steering mechanism of the
vehicle, 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 ground engaging run having:
i) a load bearing section located between the leading idler and the
trailing idler, the load bearing section transferring to the ground surface
a major portion of the load carried by the track assembly, the load
bearing section having a longitudinal extent that does not exceed a
diameter of the drive wheel;
ii) a leading section extending between the leading idler and the load
bearing section, the leading section being oriented such as to
converge toward the ground surface when the endless track is in
motion and propels the vehicle;
iii) a trailing section extending between the load bearing section and the
trailing idler, the trailing section being oriented such as to diverge from
20
the ground surface when the endless track is in motion and propels the
vehicle;
a first horizontal distance defined between the first axis of rotation and the
third axis of rotation being different from a second horizontal distance
defined
between the second axis of rotation and the third axis of rotation.
2. A track assembly as defined in claim 1, wherein the longitudinal extent of
the
load bearing section is less than the diameter of the drive wheel and wherein
the
reduced-size vehicle is an All-Terrain Vehicle (ATV) with a seat straddled by
a
user and wherein the steering mechanism has handlebars.
3. A track assembly as defined in any one of claims 1 and 2, wherein the
longitudinal extent of the load bearing section does not exceed a radius of
the
drive wheel.
4. A track assembly as defined in any one of claims 1, 2 and 3, wherein the
longitudinal extent of the load bearing section is less than a radius of the
drive
wheel.
5. A track assembly as defined in any one of claims 1 to 4, wherein an
imaginary
vertical axis that intersects the third axis of rotation also intersects the
load
bearing section.
6. A track assembly as defined in claim 5, wherein the imaginary vertical axis
intersects the load bearing section at a midpoint of the longitudinal extent
of the
load bearing section.
7. A track assembly as defined in any one of claims 1 to 6, including a
support
structure having:
i) a center portion rotatably supported at the third axis of rotation;
21
ii) a first support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the leading end of the track
assembly;
iii) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing end of the track
assembly.
8. A track assembly as defined in claim 7, wherein the first support arm
defines a
first angle with an imaginary horizontal axis which extends through the third
axis
of rotation, the second support arm defines a second angle with the imaginary
horizontal axis, the first angle being different from the second angle.
9. A track assembly as defined in any one of claims 1 to 8, wherein the drive
wheel
is in rolling contact with the inner surface of the ground engaging run.
10. A track assembly as defined in any one of claims 1 to 9, wherein the drive
wheel
is in overlapping relationship with one of the leading and trailing idlers,
when
viewed in a plane that is normal to the third axis of rotation.
11. A track assembly as defined in any one of claims 1 to 9, wherein the drive
wheel
is in overlapping relationship with the trailing idler, when viewed in a plane
normal to the third axis of rotation.
12. A track assembly as defined in any one of claims 1 to 11, wherein the load
bearing section is located closer to one of the leading and trailing idlers
than to
the other of the leading and trailing idlers.
13. A track assembly as defined in claim 7, wherein one of the first and
second
support arms is longer than the other of the first and second support arms.
22
14. A track assembly as defined in claim 7, wherein the first support arm and
the
second support arm define an obtuse angle therebetween.
15. A track assembly as defined in any one of claims 1 to 14, wherein the
endless
track is free of stiffening rods extending in a transverse direction of the
endless
track.
16. A track assembly as defined in any one of claims 1 to 15, wherein the
profile of
the endless track in the transverse direction of the endless track is
generally
convex.
17. A track assembly as defined in any one of claims 1 to 16, wherein the
endless
track has drive lugs projecting from the inner surface for engagement by the
drive
wheel.
18. A track assembly as defined in any one of claims 1 to 14, 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.
19. A track assembly as defined in claim 18, 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.
20.A track assembly as defined in any one of claims 1 to 14, wherein the
endless
track includes a plurality of track segments, each track segment including a
drive
projection extending inwardly from the inner face for engaging the drive
wheel,
and a traction lug projecting from the outer ground engaging surface, the
drive
projection registering in a longitudinal direction of the endless track with
the
23
traction lug, the portion of the track segment defined between the drive
projection
and the traction lug being free of a stiffening rod extending transversally of
the
endless track.
21.A track assembly as defined in any one of claims 1 to 14, wherein the
endless
track has a plurality of drive projections longitudinally spaced apart along
the
track for sequentially engaging the drive wheel such that rotation of the
drive
wheel imparts motion of the endless track to propel the vehicle, the endless
track
having a plurality of traction lugs projecting from the ground engaging outer
face,
the traction lugs being longitudinally spaced apart and registering with
respective
drive projections, the endless track being free of stiffening rods extending
transversally of the endless track at locations of the endless track at which
a
drive projection registers with a traction lug.
22. A track assembly as defined in any one of claims 1 to 21, wherein the
third axis
is located above the first axis and the second axis.
23. A track assembly as defined in any one of claims 1 to 22, 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.
24. A track assembly as defined in any one of claims 1 to 22, 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
24
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.
25. A track assembly as defined in any one of claims 1 to 24, wherein the
plurality of
wheels impart a generally triangular path of travel to the endless track.
26. A track assembly as defined in any one of claims 1 to 25, wherein the
plurality of
wheels define a track supporting and guiding arrangement that is in rolling
contact with the inner surface at a plurality of locations, one of said
locations
being the load bearing section.
27. A track assembly as defined in any one of claims 1 to 26, wherein the
drive
wheel has an extent along the third axis of rotation that is less than a
transverse
dimension of the endless track.
28. A track assembly as defined in any one of claims 1 to 27, wherein the load
bearing section extends below the leading section.
29. A track assembly as defined in any one of claims 1 to 28, wherein the load
bearing section extends below the trailing section.
30.A track assembly as defined in any one of claims 1 to 29, wherein the load
bearing section is located between a frontmost point and a rearmost point of
the
drive wheel in a longitudinal direction of the track assembly.
31. An all-terrain vehicle (ATV) comprising two steerable track assemblies as
defined in any one of claims 1 to 30, the two steerable track assemblies being
mounted on a common axle of the ATV.
25
32. An all-terrain vehicle as defined in claim 31, 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.
33. A track drive and support assembly for a reduced-size vehicle designed
primarily
for off-highway usage, over undeveloped roads or other unprepared surfaces
steerable by changing an orientation of the track drive and support assembly
by
a steering mechanism of the vehicle, the track drive and support assembly
having a leading end and a trailing end and comprising:
a plurality of wheels for supporting and driving an 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, 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
configured
for driving engagement with the endless track for imparting movement to the
endless track;
the plurality of wheels being configured to impart to the endless track a path
of
travel having a ground engaging run that extends between the leading idler and
the trailing idler, the ground engaging run having:
i) a load bearing section between the leading idler and the trailing idler,
the load
bearing section transferring to the ground surface a major portion of the load
carried by the track drive and support assembly, the load bearing section
having a longitudinal extent that does not exceed a diameter of the drive
wheel;
ii) a leading section extending between the leading idler and the load bearing
section, the leading section being oriented such as to converge toward the
ground surface when the endless track is in motion and propels the vehicle;
26
iii) a trailing section extending between the load bearing section and the
trailing
idler, the trailing section being oriented such as to diverge from the ground
surface when the endless track is in motion and propels the vehicle;
a first horizontal distance defined between the first axis of rotation and the
third
axis of rotation being different from a second horizontal distance defined
between
the second axis of rotation and the third axis of rotation.
34.A track drive and support assembly as defined in claim 33, wherein the
longitudinal extent of the load bearing section is less than the diameter of
the
drive wheel and wherein the reduced-size vehicle is an All-Terrain Vehicle
(ATV)
with a seat straddled by a user and wherein the steering mechanism has
handlebars.
35.A track drive and support assembly as defined in any one of claims 33 and
34,
wherein the longitudinal extent of the load bearing section does not exceed a
radius of the drive wheel.
36.A track drive and support assembly as defined in any one of claims 33 to
35,
wherein the longitudinal extent of the load bearing section is less than a
radius of
the drive wheel.
37.A track drive and support assembly as defined in any one of claims 33 to
36,
wherein an imaginary vertical axis that intersects the third axis of rotation
also
intersects the load bearing section.
38.A track drive and support assembly as defined in claim 37, wherein the
imaginary
vertical axis intersects the load bearing section at a midpoint of the
longitudinal
extent of the load-bearing section.
27
39.A track drive and support assembly as defined in any one of claims 33 to
38,
including 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 end of the track drive
and support assembly;
c) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing end of the track drive
and
support assembly.
40.A track drive and support assembly as defined in claim 39, wherein the
first
support arm defines a first angle with an imaginary horizontal axis that
intersects
the third axis of rotation, the second support arm defining a second angle
with
the imaginary horizontal axis, the first angle being different than the second
angle.
41.A track drive and support assembly as defined in any one of claims 33 to
40,
wherein the drive wheel is configured to establish a rolling contact with the
inner
surface of the ground engaging run.
42. A track drive and support assembly as defined in any one of claims 33 to
41,
wherein the drive wheel is in overlapping relationship with one of the leading
and
trailing idlers, when viewed in an imaginary plane that is normal to the third
axis.
43. A track drive and support assembly as defined in any one of claims 33 to
42,
wherein the drive wheel is in overlapping relationship with the trailing
idler, when
viewed in an imaginary plane that is normal to the third axis.
28
44. A track drive and support assembly as defined in any one of claims 33 to
43,
wherein the load bearing section is located closer to one of the leading and
trailing idlers than to the other of the leading and trailing idlers.
45. A track drive and support assembly as defined in claim 39, wherein one of
the
first and second support arms is longer than the other of the first and second
support arms.
46. A track drive and support assembly as defined in claim 39, wherein the
first
support arm and the second support arm define an obtuse angle therebetween.
47. A track drive and support assembly as defined in any one of claims 33 to
46,
wherein the third axis is located above the first axis and the second axis.
48. A track drive and support assembly as defined in any one of claims 33 to
47,
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.
49.A track drive and support assembly as defined in any one of claims 33 to
47,
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
29
positioned below the second upper horizontal imaginary plane and below the
third upper horizontal imaginary plane.
50. A track drive and support assembly as defined in any one of claims 33 to
49,
wherein the path of travel is generally triangular.
51. A track drive and support assembly as defined in any one of claims 33 to
50,
wherein the track drive and support assembly is configured such that the
plurality
of wheels establish a rolling contact with the inner surface of the endless
track at
a plurality of locations, one of said locations being the load bearing
section.
52. A track drive and support assembly as defined in any one of claims 33 to
51,
wherein the track drive and support assembly is configured such that a portion
of
the ground engaging run that defines the load bearing section is at a level
below
a lowermost peripheral portion of the leading idler and below a lowermost
peripheral portion of the trailing idler.
53.A track drive and support assembly as defined in any one of claims 33 to
52,
wherein the load bearing section is located between a frontmost point and a
rearmost point of the drive wheel in a longitudinal direction of the track
drive and
support assembly.
54. A track assembly for an All-Terrain Vehicle (ATV), steerable by
changing an
orientation of the track assembly by a steering mechanism of the ATV, 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:
30
i) a leading idler and a trailing idler 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 in driving engagement with the endless track for
imparting movement to the endless track, the drive wheel having a
third axis of rotation;
a first horizontal distance defined between the first axis of rotation and the
third axis of rotation being different from a second horizontal distance
defined
between the second axis of rotation and the third axis of rotation;
wherein the ground-engaging run has:
i) an intermediate section located between the leading idler and the
trailing idler and having a longitudinal extent not exceeding a diameter
of the drive wheel;
ii) a leading section rising from the intermediate section and extending
towards the leading idler; and
iii) a trailing section rising from the intermediate section and extending
towards the trailing idler.
55. A track assembly as defined in claim 54, wherein the longitudinal extent
of the
intermediate section is less than the diameter of the drive wheel and wherein
the
ATV has a seat straddled by a user and wherein the steering mechanism has
handlebars.
56.A track assembly as defined in any one of claims 54 and 55, wherein the
longitudinal extent of the intermediate section does not exceed a radius of
the
drive wheel.
31
57.A track assembly as defined in any one of claims 54 to 56, wherein the
longitudinal extent of the intermediate section is less than a radius of the
drive
wheel.
58.A track assembly as defined in any one of claims 54 to 57, wherein an
imaginary
vertical axis that intersects the third axis of rotation also intersects the
intermediate section.
59.A track assembly as defined in claim 58, wherein the imaginary vertical
axis
intersects the intermediate section at a midpoint of the longitudinal extent
of the
intermediate section.
60.A track assembly as defined in any one of claims 54 to 59, including a
support
structure having:
i) a center portion rotatably supported at the third axis of rotation;
ii) a first support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the leading end of the track
assembly;
iii) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing end of the track
assembly.
61.A track assembly as defined in claim 60, wherein the first support arm
defines a
first angle with an imaginary horizontal axis which extends through the third
axis
of rotation, the second support arm defines a second angle with the imaginary
horizontal axis, the first angle being different from the second angle.
62.A track assembly as defined in any one of claims 54 to 61, wherein the
drive
wheel is in rolling contact with the inner surface of the ground engaging run.
32
63. A track assembly as defined in any one of claims 54 to 62, wherein the
drive
wheel is in overlapping relationship with one of the leading and trailing
idlers,
when viewed in an imaginary plane that is normal to the third axis of
rotation.
64. A track assembly as defined in any one of claims 54 to 62, wherein the
drive
wheel is in overlapping relationship with the trailing idler, when viewed in
an
imaginary plane normal to the third axis of rotation.
65. A track assembly as defined in any one of claims 54 to 64, wherein the
intermediate section is located closer to one of the leading and trailing
idlers than
to the other of the leading and trailing idlers.
66. A track assembly as defined in claim 60, wherein one of the first and
second
support arms is longer than the other of the first and second support arms.
67. A track assembly as defined in claim 60, wherein the first support arm and
the
second support arm define an obtuse angle therebetween.
68. A track assembly as defined in any one of claims 54 to 67, wherein the
endless
track is free of stiffening rods extending in a transverse direction of the
endless
track.
69. A track assembly as defined in any one of claims 54 to 68, wherein the
profile of
the endless track in the transverse direction of the endless track is
generally
convex.
70. A track assembly as defined in any one of claims 54 to 69, wherein the
endless
track has drive lugs projecting from the inner surface for engagement by the
drive
wheel.
33
71. A track assembly as defined in any one of claims 54 to 67, 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.
72. A track assembly as defined in claim 71, 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.
73. A track assembly as defined in any one of claims 54 to 67, wherein the
endless
track includes a plurality of track segments, each track segment including a
drive
projection extending inwardly from the inner face for engaging the driving
wheel,
and a traction lug projecting from the outer ground engaging surface, the
drive
projection registering in a longitudinal direction of the endless track with
the
traction lug, the portion of the track segment defined between the drive
projection
and the traction lug being free of a stiffening rod extending transversally of
the
endless track.
74.A track assembly as defined in any one of claims 54 to 67, wherein the
endless
track has a plurality of drive projections extending inwardly from the inner
face,
the drive projections being longitudinally spaced apart along the track, the
endless track having a plurality of traction lugs projecting from the ground
engaging outer face, the traction lugs being longitudinally spaced apart along
the
track and registering with respective drive projections, the endless track
being
free of stiffening rods extending transversally of the endless track at
multiple
locations of the endless track at which a drive projection registers with a
traction
lug.
34
75.A track assembly as defined in any one of claims 54 to 74, wherein the
intermediate section is located between a frontmost point and a rearmost point
of
the drive wheel in a longitudinal direction of the track assembly.
76. A track assembly for an All-Terrain Vehicle (ATV), steerable by changing
an
orientation of the track assembly by a steering mechanism of the ATV, 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 ground engaging run having:
i) a load bearing section located between the leading idler and the
trailing idler, the load bearing section transferring to the ground surface
a major portion of the load carried by the track assembly, the load
bearing section having a longitudinal extent that does not exceed a
diameter of the drive wheel;
ii) a leading section extending between the leading idler and the load
bearing section; and
iii) a trailing section extending between the load bearing section and the
trailing idler;
35
a first horizontal distance defined between the first axis of rotation and the
third axis of rotation being different from a second horizontal distance
defined
between the second axis of rotation and the third axis of rotation.
77.A track assembly as defined in claim 76, wherein the longitudinal extent of
the
load bearing section is less than the diameter of the drive wheel and wherein
the
ATV has a seat straddled by a user and wherein the steering mechanism has
handlebars.
78.A track assembly as defined in any one of claims 76 and 77, wherein the
longitudinal extent of the load bearing section does not exceed a radius of
the
drive wheel.
79.A track assembly as defined in any one of claims 76 to 78, wherein the
longitudinal extent of the load bearing section is less than a radius of the
drive
wheel.
80.A track assembly as defined in any one of claims 76 to 79, wherein an
imaginary
vertical axis that intersects the third axis of rotation also intersects the
load
bearing section.
81.A track assembly as defined in claim 80, wherein the imaginary vertical
axis
intersects the load bearing section at a midpoint of the longitudinal extent
of the
load bearing section.
82.A track assembly as defined in any one of claims 76 to 81, including a
support
structure having:
i) a center portion rotatably connected at the third axis of rotation;
36
ii) a first support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the leading end of the track
assembly;
iii) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing end of the track
assembly.
83.A track assembly as defined in claim 82, wherein the first support arm
defines a
first angle with an imaginary horizontal axis which extends through the third
axis
of rotation, the second support arm defines a second angle with the imaginary
horizontal axis, the first angle being different from the second angle.
84.A track assembly as defined in any one of claims 76 to 83, wherein the
drive
wheel is in rolling contact with the inner surface of the ground engaging run.
85. A track assembly as defined in any one of claims 76 to 84, wherein the
drive
wheel is in overlapping relationship with one of the leading and trailing
idlers,
when viewed in an imaginary plane that is normal to the third axis of
rotation.
86. A track assembly as defined in any one of claims 76 to 85, wherein the
drive
wheel is in overlapping relationship with the trailing idler, when viewed in
an
imaginary plane normal to the third axis of rotation.
87. A track assembly as defined in any one of claims 76 to 86, wherein the
load
bearing section is located closer to one of the leading and trailing idlers
than to
the other of the leading and trailing idlers.
88. A track assembly as defined in claim 82, wherein one of the first and
second
support arms is longer than the other of the first and second support arms.
37
89. A track assembly as defined in claim 82, wherein the first support arm and
the
second support arm define an obtuse angle therebetween.
90. A track assembly as defined in any one of claims 76 to 89, wherein the
endless
track is free of stiffening rods extending in a transverse direction of the
endless
track.
91. A track assembly as defined in any one of claims 76 to 90, wherein the
profile of
the endless track in the transverse direction of the endless track is
generally
convex.
92. A track assembly as defined in any one of claims 76 to 91, wherein the
endless
track has drive lugs projecting from the inner surface for engagement by the
drive
wheel.
93. A track assembly as defined in any one of claims 76 to 89, 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.
94. A track assembly as defined in claim 93, 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.
95.A track assembly as defined in any one of claims 76 to 89, wherein the
endless
track includes a plurality of track segments, each track segment including a
drive
projection extending inwardly from the inner face for engaging the driving
wheel,
and a traction lug projecting from the outer ground engaging surface, the
drive
projection registering in a longitudinal direction of the endless track with
the
38
traction lug, the portion of the track segment defined between the drive
projection
and the traction lug being free of a stiffening rod extending transversally of
the
endless track.
96.A track assembly as defined in any one of claims 76 to 89, wherein the
endless
track has a plurality of drive projections extending inwardly from the inner
face,
the drive projections being longitudinally spaced apart along the track for
sequentially engaging the drive wheel such that rotation of the drive wheel
imparts motion of the endless track to propel the vehicle, the endless track
having a plurality of traction lugs projecting from the ground engaging outer
face,
the traction lugs being longitudinally spaced apart and registering with
respective
drive projections, the endless track being free of stiffening rods extending
transversally of the endless track at a plurality of locations of the endless
track at
which a drive projection registers with a traction lug.
97. A track assembly as defined in any one of claims 76 to 96, wherein the
leading
section is substantially straight.
98.A track assembly as defined in any one of claims 76 to 97, wherein the
trailing
section is substantially straight.
99. A track assembly as defined in any one of claims 76 to 98, wherein the
load
bearing section extends below a lowermost peripheral portion of the trailing
idler.
100. A track assembly as defined in any one of claims 76 to 99, wherein the
load
bearing section extends below a lowermost peripheral portion of the leading
idler.
101. A track assembly as defined in any one of claims 76 to 100, wherein the
third
axis is located above the first axis and above the second axis.
39
102. A track assembly as defined in any one of claims 76 to 101, 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.
103. A track assembly as defined in any one of claims 76 to 101, 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 plane being imaginary positioned below the
second upper horizontal imaginary plane and below the third upper horizontal
imaginary plane.
104. A track assembly as defined in any one of claims 76 to 103, wherein the
plurality of wheels impart a generally triangular path of travel to the
endless track.
105. A track assembly as defined in any one of claims 76 to 104, wherein the
plurality of wheels define a track supporting and guiding arrangement that is
in
rolling contact with the inner surface of the endless track at a plurality of
locations, one of said locations being the load bearing section.
106. A track assembly as defined in any one of claims 76 to 105, wherein the
drive
wheel has an extent along the third axis of rotation that is less than a
transverse
dimension of the endless track.
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107. A track assembly as defined in any one of claims 76 to 106, wherein the
load
bearing section is located between a frontmost point and a rearmost point of
the
drive wheel in a longitudinal direction of the track assembly.
108. 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 being steerable by a steering mechanism of the ATV to change
an orientation of the track assembly in order to steer the ATV, the track
assembly
comprising:
a) a plurality of wheels including:
- a drive wheel; and
- a leading idler wheel adjacent to a leading end of the track assembly
and a trailing idler wheel adjacent to a trailing end 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 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;
a bottom run of the endless track being located under the leading idler wheel
and the trailing idler wheel and extending in a longitudinal direction of the
track assembly from an axis of rotation of the leading idler wheel to an axis
of
rotation of the trailing idler wheel;
wherein:
i) the plurality of wheels is configured to bend the bottom run of
the
endless track such that, when the track assembly is on hard horizontal
ground, a ground-contacting area of the endless track in contact with
the hard horizontal ground has an extent in the longitudinal direction of
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the track assembly that does not exceed a diameter of the drive wheel;
and
ii) a distance between an 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.
109. A track assembly as defined in claim 108, wherein the extent of the
ground-
contacting area of the endless track in the longitudinal direction of the
track
assembly is less than the diameter of the drive wheel.
110. A track assembly as defined in claim 109, wherein the extent of the
ground-
contacting area of the endless track in the longitudinal direction of the
track
assembly does not exceed a radius of the drive wheel.
111. A track assembly as defined in claim 110, wherein the extent of the
ground-
contacting area of the endless track in the longitudinal direction of the
track
assembly is less than the radius of the drive wheel.
112. A track assembly as defined in any one of claims 108 to 111, 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.
113. A track assembly as defined in any one of claims 108 to 112, comprising a
track frame supporting the leading idler wheel and the trailing idler wheel
and
comprising a first arm extending downwardly and forwardly towards the leading
42
idler wheel and a second arm extending downwardly and rearwardly towards the
trailing idler wheel.
114. A track assembly as defined in claim 113, wherein the first arm is longer
than
the second arm.
115. A track assembly as defined in any one of claims 108 to 114, wherein the
drive wheel engages the bottom run of the endless track.
116. A track assembly as defined in any one of claims 108 to 115, wherein an
imaginary vertical axis that intersects the axis of rotation of the drive
wheel also
intersects the ground-contacting area of the endless track.
117. A track assembly as defined in claim 116, wherein the imaginary vertical
axis
intersects the ground-contacting area of the endless track at a midpoint of
the
ground-contacting area of the endless track in the longitudinal direction of
the
track assembly.
118. A track assembly as defined in any one of claims 108 to 117, wherein the
drive wheel is in overlapping relationship with one of the leading idler wheel
and
the trailing idler wheel, when viewed in a plane that is normal to the axis of
rotation of the drive wheel.
119. A track assembly as defined in claim 118, wherein the drive wheel is in
overlapping relationship with the trailing idler wheel, when viewed in the
plane
normal to the axis of rotation of the drive wheel.
120. A track assembly as defined in any one of claims 108 to 119, wherein the
ground-contacting area of the endless track is located closer to one of the
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leading idler wheel and the trailing idler wheel than to the other of the
leading
idler wheel and the trailing idler wheel.
121. A track assembly as defined in any one of claims 108 to 120, wherein the
endless track is free of stiffening rods extending in a transverse direction
of the
endless track.
122. A track assembly as defined in any one of claims 108 to 121, wherein a
profile
of the endless track in a transverse direction of the endless track is
generally
convex.
123. A track assembly as defined in any one of claims 108 to 122, wherein the
endless track comprises a plurality of drive lugs projecting from the inner
surface
for engagement with the drive wheel.
124. A track assembly as defined in any one of claims 108 to 120, 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 in a transverse direction of the endless track.
125. A track assembly as defined in claim 124, wherein the central portion
includes
one or more stiffening rods extending in a transverse direction of the endless
track and shorter than a transverse dimension of the endless track.
126. A track assembly as defined in any one of claims 108 to 120, wherein the
endless track includes a plurality of track segments, each track segment
including (i) a drive projection projecting from the inner face to engage the
drive
wheel and (ii) a given one of the traction projections that registers with the
drive
projection in a longitudinal direction of the endless track, the track segment
being
44
free of a stiffening rod extending transversally of the endless track between
the
drive projection and the given one of the traction projections.
127. A track assembly as defined in any one of claims 108 to 120, wherein the
endless track comprises a plurality of drive projections projecting from the
inner
surface for engaging the drive wheel, the drive projections registering with
respective ones of the traction projections in a longitudinal direction of the
endless track, the endless track being free of stiffening rods extending
transversally of the endless track at locations at which a drive projection
registers
with a traction projection.
128. A track assembly as defined in any one of claims 108 to 127, 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.
129. A track assembly as defined in any one of claims 108 to 128, wherein the
plurality of wheels imparts a generally triangular path of travel to the
endless
track.
130. A track assembly as defined in any one of claims 108 to 129, wherein the
drive
wheel has an extent along its axis of rotation that is less than a transverse
dimension of the endless track.
45
131. A track assembly as defined in any one of claims 108 to 130, wherein the
ground-contacting area is located between a frontmost point and a rearmost
point of the drive wheel in the longitudinal direction of the track assembly.
132. A track assembly as defined in any one of claims 108 to 131, wherein the
steering mechanism of the ATV comprises handlebars.
133. 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
108 to 132.
134. An all-terrain vehicle (ATV) comprising the set of track assemblies as
defined in
claim 133.
135. An ATV as defined in claim 134, wherein the steering mechanism includes a
rod for controlling an angular orientation of at least one of the at least two
track
assemblies, the rod being coupled to the at least one of the at least two
track
assemblies.
136. A track assembly for a reduced-size vehicle designed primarily for off-
highway
usage, over undeveloped roads or other unprepared surfaces steerable by
changing
an orientation of the track assembly by a steering mechanism of the vehicle,
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,
46
the leading and trailing idlers respectively having first and second axes
of rotation; and
ii) a drive wheel having a third axis of rotation and being in driving
engagement with the endless track for imparting movement to the
endless track;
the ground engaging run having:
i) a load bearing section located between the leading idler and the
trailing idler, the load bearing section transferring to the ground surface
a major portion of the load carried by the track assembly, the load
bearing section having a longitudinal extent that does not exceed a
diameter of the drive wheel;
ii) a leading section extending between the leading idler and the load
bearing section, the leading section being oriented such as to
converge toward the ground surface when the endless track is in
motion and propels the vehicle; and
iii) a trailing section extending between the load bearing section and the
trailing idler, the trailing section being oriented such as to diverge from
the ground surface when the endless track is in motion and propels the
vehicle;
a first horizontal distance defined between the first axis of rotation and the
third axis of rotation being different from a second horizontal distance
defined
between the second axis of rotation and the third axis of rotation.
137. A track assembly as defined in claim 136, wherein the longitudinal extent
of the
load bearing section is less than the diameter of the drive wheel and wherein
the
reduced-size vehicle is an All-Terrain Vehicle (ATV) with a seat straddled by
a
user and wherein the steering mechanism has handlebars.
138. A track assembly as defined in claim 137, wherein the longitudinal extent
of the
load bearing section does not exceed a radius of the drive wheel.
47
139. A track assembly as defined in claim 138, wherein the longitudinal extent
of the
load bearing section is less than a radius of the drive wheel.
140. A track assembly as defined in any one of claims 136 to 139, wherein an
imaginary vertical axis that intersects the third axis of rotation also
intersects the
load bearing section.
141. A track assembly as defined in claim 140, wherein the imaginary vertical
axis
intersects the load bearing section at a midpoint of the longitudinal extent
of the
load bearing portion.
142. A track assembly as defined in any one of claims 136 to 141, including a
support structure having:
i) a center portion with bearing means for rotatably supporting the
drive wheel such that the drive wheel can rotate about the third
axis of rotation;
ii) a first support arm mounted to the center portion and extending
along a radial direction of the drive wheel toward the leading
end of the track assembly;
iii) a second support arm mounted to the center portion of and
extending along a radial direction of the drive wheel toward the
trailing end of the track assembly.
143. A track assembly as defined in claim 142, wherein the first support arm
defines
a first angle between an imaginary horizontal axis which is different from a
second angle defined between the second arm and the imaginary horizontal axis.
144. A track assembly as defined in any one of claims 136 to 143, wherein the
drive
wheel is in rolling contact with the inner surface of the ground engaging run.
48
145. A track assembly as defined in any one of claims 136 to 144, wherein the
drive
wheel is in overlapping relationship with one of the leading and trailing
idlers.
146. A track assembly as defined in any one of claims 136 to 144, wherein the
drive
wheel is in overlapping relationship with the trailing idler.
147. A track assembly as defined in any one of claims 136 to 146, wherein the
load
bearing section is located closer to one of the leading and trailing idlers
than to
the other of the leading and trailing idlers.
148. A track assembly as defined in any one of claims 136 to 147, wherein the
load bearing section is located between a frontmost point and a rearmost point
of
the drive wheel in a longitudinal direction of the track assembly.
149. An all-terrain vehicle (ATV) comprising two steerable track assemblies as
defined in any one of claims 136 to 148.
150. A track assembly for an All-Terrain Vehicle (ATV), steerable by changing
an
orientation of the track assembly by a steering mechanism of the ATV, 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;
b) a plurality of wheels for supporting and driving the endless track, the
endless
track having a plurality of consecutively arranged segments, areas of juncture
between adjacent segments corresponding to locations at which the plurality
of wheels contact the inner surface of the endless track, the plurality of
wheels including:
49
i) a leading idler and a trailing idler, the leading and trailing idlers
being in
a spaced apart relationship, the leading idler having a first axis of
rotation, the trailing idler having a second axis of rotation;
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 plurality of segments including a leading segment, a trailing segment, and
an intermediate segment between the leading segment and the trailing
segment, wherein:
i) the leading segment extends from the leading idler to the intermediate
segment;
ii) the trailing segment extends from the intermediate segment to the
trailing idler;
iii) the intermediate segment descends lower than the leading and trailing
segments;
iv) the intermediate segment has a longitudinal extent not exceeding a
diameter of the drive wheel; and
v) a first horizontal distance defined between the first axis of rotation
and
the third axis of rotation is different from a second horizontal distance
defined between the second axis of rotation and the third axis of
rotation.
151. A track assembly as defined in claim 150, wherein the longitudinal extent
of
the intermediate segment is less than the diameter of the drive wheel.
152. A track assembly as defined in any one of claims 150 and 151, wherein the
longitudinal extent of the intermediate segment does not exceed a radius of
the
drive wheel.
50
153. A track assembly as defined in any one of claims 150 to 152, wherein the
longitudinal extent of the intermediate segment is less than a radius of the
drive
wheel.
154. A track assembly as defined in any one of claims 150 to 153, wherein an
imaginary vertical axis that intersects the third axis of rotation also
intersects the
intermediate segment.
155. A track assembly as defined in claim 154, wherein the imaginary vertical
axis
intersects the intermediate segment at a midpoint of the longitudinal extent
of the
intermediate segment.
156. A track assembly as defined in any one of claims 150 to 155, including a
support structure having:
i) a center portion rotatably supported at the third axis of rotation;
ii) a first support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the leading end of the track
assembly;
iii) a second support arm mounted to the center portion and extending along a
radial direction of the drive wheel toward the trailing end of the track
assembly.
157. A track assembly as defined in claim 156, wherein the first support arm
defines a first angle with an imaginary horizontal axis which extends through
the
third axis of rotation, the second support arm defines a second angle with the
imaginary horizontal axis, the first angle being different from the second
angle.
158. A track assembly as defined in any one of claims 150 to 157, wherein the
drive wheel is in rolling contact with the inner surface of a ground engaging
run of
the endless track.
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159. A track assembly as defined in any one of claims 150 to 158, wherein the
drive wheel is in overlapping relationship with one of the leading and
trailing
idlers, when viewed in a plane that is normal to the third axis of rotation.
160. A track assembly as defined in any one of claims 150 to 158, wherein the
drive wheel is in overlapping relationship with the trailing idler, when
viewed in a
plane normal to the third axis of rotation.
161. A track assembly as defined in any one of claims 150 to 160, wherein the
intermediate segment is located closer to one of the leading and trailing
idlers
than to the other of the leading and trailing idlers.
162. A track assembly as defined in claim 156, wherein one of the first and
second support arms is longer than the other of the first and second support
arms.
163. A track assembly as defined in claim 156, wherein the first support arm
and the
second support arm define an obtuse angle therebetween.
164. A track assembly as defined in any one of claims 150 to 163, wherein the
endless track is free of stiffening rods extending in a transverse direction
of the
endless track.
165. A track assembly as defined in any one of claims 150 to 164, wherein the
profile of the endless track in the transverse direction of the endless track
is
generally convex.
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166. A track assembly as defined in any one of claims 150 to 165, wherein the
endless track has drive lugs projecting from the inner surface for engagement
by
the drive wheel.
167. A track assembly as defined in any one of claims 150 to 163, 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.
168. A track assembly as defined in claim 167, 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.
169. A track assembly as defined in any one of claims 150 to 163, wherein the
endless track includes a plurality of track segments, each track segment
including a drive projection extending inwardly from the inner face for
engaging
the drive wheel, and a traction lug projecting from the outer ground engaging
surface, the drive projection registering in a longitudinal direction of the
endless
track with the traction lug, the portion of the track segment defined between
the
drive projection and the traction lug being free of a stiffening rod extending
transversally of the endless track.
170. A track assembly as defined in any one of claims 150 to 163, wherein the
endless track has a plurality of drive projections longitudinally spaced apart
along
the track for sequentially engaging the drive wheel such that rotation of the
drive
wheel imparts motion of the endless track to propel the vehicle, the endless
track
having a plurality of traction lugs projecting from the ground engaging outer
face,
the traction lugs being longitudinally spaced apart and registering with
respective
drive projections, the endless track being free of stiffening rods extending
53
transversally of the endless track at locations of the endless track at which
a
drive projection registers with a traction lug.
171. A track assembly as defined in any one of claims 150 to 170, wherein the
third axis is located above the first axis and the second axis.
172. A track assembly as defined in any one of claims 150 to 171, 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.
173. A track assembly as defined in any one of claims 150 to 171, 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.
174. A track assembly as defined in any one of claims 150 to 173, wherein the
plurality of wheels impart a generally triangular path of travel to the
endless track.
175. A track assembly as defined in any one of claims 150 to 174, wherein the
drive
wheel has an extent along the third axis of rotation that is less than a
transverse
dimension of the endless track.
54
176. A track assembly as defined in any one of claims 150 to 175, wherein the
intermediate segment is located between a frontmost point and a rearmost point
of the drive wheel in a longitudinal direction of the track assembly.
177. An all-terrain vehicle (ATV) comprising two steerable track assemblies as
defined in any one of claims 150 to 176, the two steerable track assemblies
being mounted on a common axle of the ATV.
178. An all-terrain vehicle as defined in claim 177, 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.
