ENDLESS TRACK FOR A TRACK PROPELLED VEHICLE

CHENILLE POUR VEHICULE CHENILLE

English Abstract

The ground engaging outer side of an endless track of a track-propelled vehicle displays a series of longitudinally spaced profiles which are defined by a central portion and two opposite lateral portions; the rubber material of the lateral portions of the body has a hardness which is greater than the hardness of the rubber material of the central portion of the body.

French Abstract

Le côté extérieur entrant en contact avec le sol d'une chenille sans fin pour véhicule à chenilles présente une suite de profilés espacés longitudinalement qui comprennent une partie centrale et deux parties latérales opposées. La dureté du caoutchouc des parties latérales du corps est supérieure à celle du caoutchouc de la partie centrale du corps.

Claims

CLAIMS
1. An endless track for a track-propelled vehicle, comprising a body
made of a reinforced rubber material, the body having a ground-engaging outer
side on which are disposed a series of longitudinally spaced profiles, and an
inner side; said body defining a laterally extending central portion and two
opposite lateral portions; said track being characterized in that the rubber
material of said lateral portions of said body has substantially a hardness
which is
greater than the hardness of the rubber material of the central portion of
said
body.
2. An endless track according to claim 1, characterized in that the
rubber material of the lateral portions of the body has an average hardness of
between 75 and 90 duro A.
3. An endless track according to claim 1, characterized in that the
rubber material of said lateral portions of the body has an average hardness
of
about 80 duro A.
4. An endless track according to claim 1, characterized in that the
rubber material of said central portion of the body has an average hardness of
between 55 and 75 duro A.
5. An endless track according to claim 1, characterized in that the
rubber material of the central portion of the body has an average hardness of
about 60 duro A.
6. An endless track according to any one of claims 1 to 5, wherein
each profile has an identical configuration.
7. An endless track according to any one of claims 1 to 5, wherein
some profiles vary in configuration.
8. An endless track according to any one of claims 1 to 5, wherein
said opposite lateral portions have a same configuration.

Description

CA 02456887 2004-02-04
-1 -
TITLE OF THE INVENTION
ENDLESS TRACK FOR A TRACK-PROPELLED VEHICLE
FIELD OF THE INVENTION
The present invention pertains to the construction of an endless track
for a track-propelled vehicle.
BACKGROUND OF THE INVENTION
Endless tracks for track-propelled vehicles are well known. They
essentially consist of an endless body made of reinforced rubber material
wherein the ground engaging outer side of the body is formed of a series of
longitudinally spaced profiles. Endless tracks mounted on snowmobiles are
usually provided with a series of longitudinally spaced embedded rods to
reinforce the rubber material. However, on other vehicles such as vehicles
which
are driven on snow or grounds that would not adequately support wheels,
endless tracks, which are usually of smaller width than that found on
snowmobiles, are provided without the presence of reinforcing rods as
indicated
above.
In Canadian patent application 2,319,934 filed September 18, 2000 in
the name of Soucy et al., there is provided a rubber band track with various
hardnesses. However, the track described is characterized by a central portion
made of rubber material having a hardness which is greater than the hardness
of the rubber material in the opposite lateral band portions of the body.
However, it has been noted that some resiliency is needed in the central
portion for the wheels which bear on the inner surface of the endless track.

CA 02456887 2004-02-04
-2-
STATEMENT OF THE INVENTION
The present invention is therefore concerned with providing an endless
track for a track-propelled vehicle which overcomes the above-described
problem.
This is achieved by providing an endless track for a track track-propelled
vehicle which comprises a body made of a reinforced rubber material, the body
having a ground-engaging outer side on which are disposed a series of
longitudinally spaced profiles, and an inner side; the body defines a
laterally
extending central portion and two opposite lateral portions; the track is
characterized in that the rubber material of the lateral portions of the body
has
substantially a hardness which is greater than the hardness of the rubber
material
of the central portion.
In one form of the invention, the rubber material of the lateral portions
of the body has an average hardness of between about 75 and about 90 duro A.
In another form of the invention, the rubber material of the central
portion of the body has an average hardness of between about 55 and about 75
duro A.
Objects and further scope of applicability of the present invention will
become apparent from the detailed description given hereinafter. It should be
understood, however, that this detailed description, while indicating
preferred
embodiments of the invention, is given by way of illustration only, since
various
changes and modifications within the spirit and scope of the invention will
become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of a portion of a track made in
accordance with the present invention;

CA 02456887 2004-02-04
-3-
Figure 2 is a cross-sectional view taken along lines 2-2 of figure 1;
Figure 3 is a cross-sectional view taken slang lines 3-3 of figure 1; and
Figure 4 is a perspective view of a portion of another track made in
accordance with the present invention.
DETAILED DESCRIPTION
Referring to figures 1, 2 and 3, there is shown a portion 10 of an endless
track made in accordance with the present invention. The track is formed of
molded reinforced rubber material, the construction of which is well known in
the
art and need not be described in detail herein.
The track has an inner side 12 which displays a series of longitudinally
spaced drive lugs 13 for engagement with drive wheels (not shown) associated
with the suspension assembly of track-propelled vehicles, and an outer side 14
which displays a series of longitudinally spaced laterally extending profiles
16, 18
and 20, preferably of identical configuration.
Each profile 16 has a central region 16' and opposite lateral band
portions 16". The central region 16' has a constant height while the opposite
lateral portions 16" are stepped to the opposite side edges 17 of the track.
The present invention is concerned with making the central region 16'
of a rubber material having a hardness which is less than the hardness of the
rubber material of the lateral portions 16" of the body. However, it has been
found that, during the molding process, the soft rubber material will somewhat
flow to the lateral portions so that references X and Y represent
substantially the
respective areas of soft and hard rubber material which, in practice, are
present
in the finished track.

CA 02456887 2004-02-04
-4-
Referring to figure 4, there is shown a portion 110 of another endless
track made in accordance with the present invention. The track is formed of
molded reinforced rubber material, the construction of which is well known in
the
art and need not be described in detail herein.
The track has an inner side 112 which displays a series of longitudinally
spaced drive lugs 113 for engagement with drive wheels (not shown) associated
with the suspension assembly of track-propelled vehicles, and an outer side
114
which displays a series of longitudinally spaced laterally extending profiles
116,
118 and 120. As can be seen in figure 4, the profiles differ in configuration
from
one profile to the other. However, in this embodiment the opposite lateral
portions have the same confiiguration.
Each profile 116 has a central region 116' and opposite lateral band
portions 116 ". The central region 116' has a constant height while the
opposite
lateral portions 116" are stepped to the opposite side edges 117 of the track.
The present invention is concerned with making the central region 116'
of a rubber material having a hardness which is less than the hardness of the
rubber material of the lateral portions 11fi" of the body. However, it has
been
found that, during the molding process, the soft rubber material will somewhat
flow to the lateral portions so that references X' and Y' represent
substantially the
respective areas of soft and hard rubber material which,~in practice, are
present
in the finished track.
In one form of the invention, the rubber material of the lateral portions
of the body or in areas Y and Y' has an average hardness of between about 75
and about 90 duro A, preferably 80 duro A.
In another form of the invention, the rubber material of the central
portion, or areas X and X', of the body has an average hardness of between
about 55 and about 75 duro A, preferably 60 duro A.

CA 02456887 2004-02-04
-5-
Although the invention has been described above with respect to one
specific form, it will be evident to a person skilled in the art that it may
be modified
and refined in various ways. It is therefore wished to have it understood that
the
present invention should not be limited in scope, except by the terms of the
following claims.

Representative Drawing