Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a track for a vehicle.
Tracks used in the drive mechanism of vehicles are well known.
In the case of snow vehicles such as snowmobiles, snowblowers and the like,
the track is typically in the form of an endless belt and has a ground Png~ging
surface with a tread design on it to provide suitable traction. Often, the treads
are shallow and are configured to provide reasonable traction over a variety of
terrain and weather conditions. Unfortunately, these common shallow treads
do not provide adequate traction in many conditions. Furthermore, the
configuration of these treads is often such that snow is carried along the length
of the snow vehicle before it is thrown clear of the snow vehicle from its rear.This design can pose problems because it increases the chances of snow
clogging the treads and accumulating above the belt, beneath the chassis of the
snow vehicle.
To deal with some of the problems associated with conventional
tread design~, many different tread configurations have been considered. For
example, U.S. Patent No. 4,957,472 to Nakano shows an endless track for a
snow vehicle suitable for both deep snow and icy conditions. The endless track
has a ground eng~ing surface on which an alternately repeating tread
configuration is provided. The treads are transverse and extend across the full
width of the track. The treads are also arranged in pairs, with one tread of each
pair being designed for soft snow and the other tread of each pair being
designed for hard packed snow or ice.
Although the Nakano track is designed to improve traction in
deep snow, problems exist with this tread design. Specifically, the transverse
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tread configuration results in snow being carried along the length of track which
may result in snow clogging the treads and accumulating above the belt,
beneath the chassis of the snow vehicle.
U.S. Patent No. 4,573,746 to Prinoth shows an endless track for
a motor vehicle which comprises two laterally spaced, parallel half tracks joined
together by rigid, U-shaped cross-members. Cleats project from each half track
to enhance traction. The cleats are angled with respect to the center line of the
track with the leading surface of each angled cleat facing away from the center
of the track.
Although many tread configurations have been considered,
improved tread designs for tracks to enhance traction in severe conditions such
as in deep snow, and when ascending and descending hills are continually being
sought. It is therefore an object of the present invention to provide a novel
track for a vehicle.
According to one aspect of the present invention there is provided
a track for a vehicle comprising:
an exterior surface to contact a ground surface; and
a plurality of primary cleats on said exterior surface and
projecting outwardly therefrom, said primary cleats being arranged in sets with
each set being located on an opposite side of the center line of said track, at
least some of the primary cleats in each set being angled with respect to said
center line and dçfining leading surfaces presented towards said center line.
Preferably, the sets of primary cleats are staggered so that each
primary cleat of one set is located between adjacent primary cleats of the other
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set. Also, it is pr~r~l~d that all of the primary cleats in each set are angled
with respect to the center line. Furthermore, it is plc~rt;lled that all of the
primary cleats have a row of teeth formed thereon. Preferably, apertures are
provided in the track near its sides so that when the track is used on a snow
vehicle, the apellules allow snow to pass through the track and lubricate the
slides of the snow vehicle.
Preferably, the primary cleats are generally ll~pe;Goidal in shape
to define generally planar leading and trailing surfaces. It is also pr~r~red that
the track includes a plurality secondary cleats projecting outwardly from the
exterior surface. In this embodiment, the secondary cleats are arranged in sets
with each set of secondary cleats being located on an opposite side of the center
line ~dj~cent the outer side edges of the track. Preferably, each set of
secondary cleats is aligned with the set of primary cleats that is on the same
side of the track center line.
In a plcr~lled embodiment, each secondary cleat is generally
trapezoidal in shape and has a curved outermost end to define a leading surface
having portions oriented at different angles to the center line. Each secondary
cleat may also have a curved innermost end with the outermost end of each
secondary cleat being curved more significantly than the innermost end thereof.
Each secondary cleat may also have a row of teeth formed thereon.
According to another aspect of the present invention there is
provided a track for a vehicle comprising:
an exterior surface to contact a ground surface;
a plurality of primary cleats on said exterior surface and
projecting outwardly therefrom, said primary cleats being arranged in sets with
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each set being located on an opposite side of the center line of said track, theprimary cleats in each set being angled with respect to said center line and
d~fining first leading surfaces presented towards said center line; and
a plurality secondary cleats projecting outwardly from said
exterior surface, said secondary cleats being arranged in sets, each set of
secondary cleats being located on an opposite side of said center line adjacent
the outer side edges of said track, the secondary cleats in each set dtfining
second leading surfaces.
According to still yet another aspect of the present invention
there is provided a track for a vehicle comprising:
an exterior surface to contact a ground surface;
a plurality of primary cleats on said exterior surface and
projecting outwardly therefrom, said primary cleats being arranged in sets with
each set being located on an opposite side of the center line of said track, thesets of primary cleats being staggered so that a primary cleat of one set is
located between adjacent primary cleats of another set, the primary cleats in
each set being angled with respect to said center line and defining first leading
surfaces presented towards said center line; and
a plurality secondary cleats projecting outwardly from said
exterior surface, said secondary cleats being arranged in sets, each set of
secondary cleats being located on an opposite side of said center line adjacent
the outer side edges of said track, each set of secondary cleats being aligned
with the set of primary cleats that is on the same side of the center line, eachof said secondary cleats having a curved outermost end to define a second
leading surface having portions oriented at different angles to said center line.
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The present invention provides advantages in that the orientation
of the cleats on the track is such to provide multi-directional traction.
Furthermore, when the track is used on a snow vehicle and the track is rotated
to drive the vehicle in a forward direction, snow is pulled across the center line
of the track by the leading surfaces of the primary cleats before the snow is
discharged to the sides of the snow vehicle. This creates a cushion of snow
beneath the center of the snow vehicle allowing the snow vehicle to float in
deep snow. Also because snow is discharged to the sides of the snow vehicle,
snow is able to pass through the apertures to lubricate the track slides of the
snow vehicle, and the likelihood of snow accumulating in the tunnel of the snow
vehicle is minimi7~d.
An embodiment of the present invention will now be described
more fully, with reference to the accompanying drawings, in which:
Figure 1 is a perspective view taken from below and from the
rear of a portion of a track for a vehicle;
Figure 2 is an enlarged perspective view of the portion illustrated
in Figure l;
Figure 3 is a perspective view of the portion illustrated in Figure
2 taken from above and from the front;
Figure 4 is a plan view of the portion illustrated in Figure 2;
Figure S is a plan view of the portion illllstr~tP~ in Figure 3;
Figure 6 is a side elevation of the portion illustrated in Figure 2;
and
Figure 7 is an end view of the portion illllst~tP~ in Figure 2.
R~ferring now to Figures 1 to 7, a track for use on a vehicle (not
shown) is shown and is generally indicated by reference numeral 10. The track
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10 is in the form of an endless belt and is designed to improve the pelfi~l,lance
of the vehicle. Although only a portion of the track 10 is illust~ted, it shouldbe realized that the track is continuous along the chain dot line. In this
embodiment, the track 10 will be described for use on a snow vehicle.
As can be seen, the track has an exterior surface 12 to contact
a snow covered ground surface (not shown) as well as an interior surface 14.
The track is formed of reinforced rubber and is manufactured in a conventional
m~nner Two rows of spaced apertures 16 extend about the circumference of
the belt. Each row of apertures 16 is positioned on an opposite side of the
center line 18 of the track 10. The apertures 16 allow snow to pass through the
track 10 to assist in the lubrication of the snow vehicle slides (not shown). Toreinforce the track, transverse ribs 20 (best seen in Figure 4) are provided on
the exterior surface 12 and span the full width of the track 10. The ribs 20
extend the circumference of the track 10 at spaced locations and are positioned
so that each rib 20 separates successive apertures 16 in each row.
On the interior surface 14 of the track are a plurality of
outwardly projecting driving lugs 26 (see Figures 3 and 5). The lugs are
arranged in transverse rows in line with the ribs 20. The lugs 26 in each row
are spaced apart and are arranged so that the track is symmetrical about the
center line 18 of the track when looking at the interior surface 14.
A tread arrangement 30 is provided on the exterior surface 12 to
enhance vehicle traction. Specifically, the tread arrangement includes a
plurality of inner, outwardly projecting primary cleats 32 and a plurality of
outer, outwardly projecting secondary cleats 34.
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The primary cleats 32 are arranged in sets with each set of
primary cleats being located on an opposite side of the center line 18 of the
track 10. The two sets of primary cleats 32 are staggered so that each cleat of
one set is located midway between adjacent cleats in the other set. Each
primary cleat 32 has a generally t~ oidal body 36 and is angled with respect
to the center line 18 to define generally planar leading and trailing surfaces 38
and 40 respectively (see Figures 2, 4, 6 and 7). The orientation of each
primary cleat is such that the leading surface 38 is presell~ed towards the center
line 18 when the track 10 is driven to propel the snow vehicle in a forward
direction as indicated by arrow 42. The orientation of the primary cleats 32 is
also selected to achieve the best compromise between forward and lateral
traction and rolling resistance.
The ends of each primary cleat 32 are curved giving the primary
cleats the general appeal~lce of a lazy "S". The innermost end 32a of each
primary cleat curves towards the center of the track 10 while the outermost end
32b of each primary cleat curves towards an outer edge of the track. The
outermost end of each primary cleat 32 also termin~t~d on one of the ribs 20.
A row of ca~t~llat~cl teeth 44 are formed along the top of each primary cleat 32.
The secondary cleats 34 are also arranged in sets with each set
of secondary cleats being located on an opposite side of the center line 18 of the
track 10 and near an outer edge of the track. Each set of secondary cleats is
aligned with the set of primary cleats 32 that is on the same side of the centerline 18.
Each secondary cleat 34 is generally trapezoidal and extends
along one of the ribs 20. Similar to the primary cleats, the ends of the
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secondary cleats are also curved. The innermost end 34a of each secondary
cleat curves slightly in the forward direction 42. The outermost end 34b of
each secondary cleat also curves in the forward direction but the curve is more
significant. The configuration of each secondary cleat 34 defines a leading
surface 46 having a generally transverse planar portion 46a surrounded by
smaller angled portions 46b and 46c (see Figures 4 and 7). The smaller angled
portions of each leading surface 46 are oppositely inclined with respect to the
center line 18 of the track. A raw of c~tell~ted teeth 48 is also formed on the
top of each secondary cleat 34. The row of teeth 48 on each secondary cleat
34 begins at the innermost end 34a of the cleat but terminates before the curvedoutermost end 34a.
A pair of generally t~ oidal, bridging cleats 50 projects
outwardly from each transverse supporting rib 20. The bridging cleats are
shallow compared to the primary and secondary cleats 32 and 34 respectively.
The bridging cleats 50 of each pair are spaced apart so that each bridging cleatis positioned between adjacent apertures 16 in a different row. Thus, every
second pair of bridging cleats 50 spans the gap between a primary cleat and a
secondary cleat.
The operation of track 10 when installed on a snowmobile will
now be described. ~lth the track installed on a snowmobile, the interior
surface 14 runs along the slides of the snowmobile. When the snowmobile is
in for~vard gear, the snowmobile drive engages the driving lugs 26 to rotate thetrack 10 in the direction of arrow 42. A length of the exterior surface 12 of the
track contacts the snow covered ground surface allowing the cleats 32, 34 and
50 to dig into the snow.
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As the track 10 is rotated, each primary cleat 32 pulls snow
towards the center of the track 10 due to the orientation of the leading faces 38.
The arrangement of the two sets of primary cleats creates a cross-flow of snow
as snow is pulled across the center line 18 of the track by the leading faces 38before being thrown clear of the snowmobile via its sides. This flow of snow
creates a cushion of snow along the center line of the track allowing the
snowmobile to "float", and this is especially advantageous in deep light snow.
Also, because snow is pulled across the track 10, only a small amount of snow
is carried along the length of the track. Consequently, very little snow is
carried into the tunnel of the snowmobile. Moreover, because snow is thrown
to the sides of the snowmobile, snow is able to pass through the track 10 via
the apertures 16 and lubricate the slides on which the track is mounted.
The secondary cleats 34 provide enhanced traction during
cornering by p~esP~ ing leading surfaces 46 oriented at different angles to the
center line 18 of the track. The teeth 44 and 48 on both the primary and
secondary cleats provide enhanced gripping on hard packed surfaces.
As will be appreciated by those of skill in the art, the height of
the primary and secondary cleats can be varied to make the track more suitable
for different snow conditions. Also, those of skill in the art should recognize
that other cleat orientations can be selected to achieve the desired cross-flow of
snow beneath the track.
The present invention provides several advantages in that due to
the orientation of the primary and secondary cleats, traction is provided along
a plurality of axes relative to center line of the track. This multi-directionaltraction subst~nti~lly adds to the stability of the vehicle and is particularly well
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suited for safely ascending and descending hills. Also, in the case of snow
vehicles, the orientation of the primary cleats creates a cushion of snow along
the center line of the track allowing the snow vehicle to "float" in deep light
snow. Also, because snow is pulled across the track, only a small amount of
snow is carried along the length of the track decreasing the likelihood of snow
accumulating in the tunnel of the snow vehicle.
Although the track and its operation has been described with
particular reference to snow vehilces, it should be apparel-t to those of skill in
the art that the present track design is suitable for use on a variety of vehicles.
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