Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02369265 2002-O1-23
MULTIPLE-METAL CROSSp~CE
Field of the Invention
[0001 ] The present invention relates generally to a crosspiece of a track of
a track-type
vehicle, and more specifically to a multiple-piece (or multiple-rrtetal)
crosspiece.
Back;~und of the Tnvention
[0002] Track-type vehicles typically comprise a powered frame with two
parallel tracks
aligned in the direction of motion of the vehicle. Tracked vehicles are often
used in such
applications as ski slope grooming, where the slippery snowlice and steep
terrain make traction
between the tracks and the ground critical. For this reason, a plurality of
traction enhancing
crosspieces are secured to the outer surface of each track.
[0003] FIG. 1 illustrates one conventional type of crosspiece 300, which
comprises a
single elongated "U" shaped steel piece. The steel cmsspieee can be easily
bolted to the track 6.
While steel is strong and malleable enough to handle the higb forces
experienced at the tip of
such crosspieces, steel rusts, becomes unsightly, and is heavy. Additionally,
snow and other
debris can accumulate on the inside of the opening 302 of the 'nJ" during use,
only to melt and
form puddles under the vehicle during storage.
[0004] FIG. 2 illustrates another conventional crosspiece 310, which has an
enclosed
interior hole 312 that prevents the accumulation of debris therein. However,
such a construction
severely restricts access to the nuts 314 of the bolts 316 used to secure the
crosspiece to the track
because the nuts 314 must be disposed within the enclosed interior hole 312.
To do this, the nuts
314 must be positioned on a strip that is disposed within the hole 312. The
strip may be removed
once the nuts are fastened.
[0005] The conventional crosspiece 310 may be extruded aluminum. While an
aluminum crosspiece 310 is aesthetically appealing, does not rust, is lighter,
and has better
climbability in wet SiIOW, an all-ahuninum crosspiece 310 is extremely
expensive. Further,
aluminum is more brittle than steel, As a result, the tip of an all-aluminum
crosspiece is more
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prone to chipping than the tip of a steel crosspiece. This results in more
frequent replacement of
the all-aluminum crosspieces.
[0006] While in the conventional crosspiece 310, the bolts 316 are fed through
smooth
holes 318 and threaded onto the nuts 314, other conventional crosspieces
utilize threaded holes
within the crosspiece in order to eliminate the need for additional nuts 314.
While the
elirnunation ofthe nuts 314 solves the problem of access to the nuts 314,
threaded holes wear
quickly if the crosspiece is made of aluminum.
[0007] As illustrated in FIG. 3, U.S. Patent No. 5,265,949 discloses another
conventional
crosspiece 320. The crosspiece 320 comprises sheet steel that is bent to form
an enclosed interior
hole 322. As that patent describes, the crosspiece 320 is bolted to the track
6 through hole 324,
which may or may not be threaded, a nut being used if the bolt hole is not
threaded. A spike 326
may be optionally bolted (via bolt 328) to the crosspiece 320. Y.ike the
crosspiece 300, the steel
crosspiece 320 disadvantageously rusts, becomes unsightly, and is heavy.
[0008] U:S. Patent No. 4,218,1 Ol discloses a crosspiece that is similar to
the crosspiece
320, except that instead of attaching a spike 326 to the crosspiece, hardened
steel ice talks axe
intermittently welded to the crosspiece.
[0009) FIG. 4 illustrates yet another conventional crosspiece 430, which
utilizes an
aluminum base 432 and a steel tip 434. The tip 434 and base 432 are secured
together using
horizontally extending bolts 436. While such a design advan#a,geously uses
malleable steel at the
tip 432, where stress on the crosspiece 430 is the greatest, the horizontally
extending bolts 436
significantly widen the tip portion and reduce the crosspiece's ability to
peneteate the snore. As
illustrated in FIG. 3, the crosspiece 320 suffers from the same drawback when
the spike 326 is
attaches using horizontal bolts 328.
2
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Summary of the Invention
[0010] In view of the foregoing, it is an aspect of the gresent invention to
provide a
durable easily-replaceable crosspiece.
[0011 ] It is a farther aspect of the present invention to provide a
crosspiece having a
malleable replaceable narrow tip_
[0012] It is yet a further aspect of the present invention to provide an
inexpensive
crosspiece.
[0013] It is yet a fiu ther aspect of the present invention to provide a
crosspiece that
prevents (or at least minimizes} the accumulation of debris therein.
[0014] It is yet a further aspect of the present invention to provide a
tracked vehicle
having crosspieces that possess the above aspects.
[0015] The crosspiece and tracked vehicle of the present invention accomplish
these and
other objects, which will become apparent in the discussion that follows.
[OOI6~ In accordance with the present invention, a crosspiece is provided that
comprises
a base having longitudinal and vertical axes, a tip disposed above the base,
at least one vertical
through-hole extending through both the base and the tip, and at least one
fastener extending
through the at least one vertical through-hole to connect the tip to the base.
The base is extruded
aluminum and the tip is steel. The base has a longitudinal through-hole. The
at least one
through-hole comprises a plurality of longitudinally spaced through-holes in
the base and tip.
The at least one fastener comprises a fastener for each of the plurality of
through-holes. The
fasteners are nuts and bolts and are mounted such that the nuts axe disposed
above the base so as
to be accessible from a direction perpendicular to the longitudinal axis of
the base. The tip has a
vertical portion and a substantially horizontal portion that is positioned on
top of a top portion of
the base. The substantially horizontal portion includes a downwardly extending
portion an an
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opposite side of the substantially horizontal portion from the vertical
portion, and the base
includes a recess to accommodate the downwardly extending portion. An outer
side of the
downwardly extending portion is flash with an exterior surface of the base.
The base has an
upwardly projecting portion defining a projecting lateral surface. that is
flush witl3 a surface of
the tip at a location of the upwardly projecting portion.
[0017) A tracked vehicle embodying the present invention comprises a powered
frame, at
least one track mounted to the powered frame for propulsion of the vehicle,
and
at least one of the above~described crosspieces mounted on the track such that
a bottom of the
base is connected to an outer surface ofthe at least one track. Each bolt and
nut simultaneously
secures the tip to the base and the base to the track: A plurality of
crosspieces are mounted to the
track in a laterally spaced relationship.
Brief Description of the Drawings
[0018) For a better understanding ofthe present invention as well as other
objects and
further features thereof, reference is made to the following description which
is to be used in
conjunction with tl3e accompanying drawings, where:
FIGS. 1-4 are cross-sectional views ofvarious conventional crosspieces;
FIG. 5 is a side view of a tracked vehicle according to the present invention;
FIG. 6 is a top detail view of a track including crosspieces of the present
invention;
FIG. 7 is a cross-sectional view of the track and crosspiece according to a
first
embodiment of the present invention; and
FIG. 8 is a cross-sectional view of a second embodiment of the present
invention.
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Description of the Preferred Embodiments
j0019] As illustrated in FIG. 5, the tracked vehicle 2 of the present
invention has a
powered frame 4 and two parallel tracks 6 mounted to the powered frame 4 for
propulsion of the
vehicle 2.
[0020] To simplify the explanation of the present invention, the longitudinal,
lateral, and
vertical reference axes will be defined relative to the crosspiece as follows
(See FIGS. 6 and 7).
The longitudinal axis extends in a direction that is parallel to the outer
surface 6a of the track 6
where the crosspiece 100 is mounted on the track 5 and perpendicular to the
direction of travel of
the vehicle 2. The lateral axis is parallel to the track 6 and is parallel to
the direction of travel of
the track 6. The vertical axis is perpendicular to the outer surface fa of the
track, the positive
direction extending upwardly away from the outer surface da.
[0021] FIG. 5 shows a detailed top view ofthe tracks. The track 6 comprises a
plurality
of endless bands 8. A plurality of crosspieces I00 are mounted on the outer
surface 6a of the
track 6 to provide traction. Each longitudinally elongated crosspiece 100 is
mounted such that
its longitudinal axis is perpendicular to the direction of travel of the track
6. The crosspieces 100
are laterally spaced from each other and may be alternately longitudinally
staggered from each
other as shown in FiG. 6.
[0022] FIG: 7 illustrates a cross-sectional view of a crosspiece loo according
to a first
embodiment of the present invention. Each crosspiece 100 comprises a tip 120
and a base 140.
[0023] Hereinafter, the tip 120 will be described with reference to FIG. 7.
The tip 120 is
longitudinally elongated and has a horizontal portion 122 through which a
plurality of
longitudinally spaced vertical through-holes 124 extend. A vertical portion
126 extends
upwardly from a forward lateral side of the ho~zontal portion 122 to form a
narrow top 128 that
is adapted to penetrate the snow/loose ground and provide traction for the
track 6. A
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downwardly extending portion 130 extends downwardly from the backward lateral
side of the
horizontal portion 122.
[0024] The tip 120 is preferably made of steel because steel is strong and
malleable.
However, any other suitable material that would be known to one skilled in the
art could also be
used.
[0025] Hereinafter, the base 140 will be described with reference to FIG. 7.
The base
140 is longitudinally elongated. A plurality of vertical through-holes 142
that align with the
plurality of vertical through-holes 124 of the tip extend between a top
portion 144 of the base
and a bottom 146 of the base. The top portion 144 abuts (or mates with) the
horizontal portion
122 of the tip.
[0026] A forward lateral side 148 of the base includes an upwardly projecting
portion
150 that defines a projecting lateral surface 152 that is flush with a surface
154 of the vertical
portion of the tip 120 in the vicinity of the upwardly projecting portion 150.
The flush interface
prevents debris from wedging between the tip i20 and base 140 <~nd prying the
tip 120 from the
base 140 when the forward lateral side 148 pushes against the ground when the
vehicle is
moving. Depending on the desired lateral orientation of each crosspiece 100;
debris will be
pushed against the interface in one of the forward and reverse travel
directions.
j0027] Similarly, a backward lateral side I 56 of the base includes a recess
158 to
accommodate the downwardly extending portion 13 0 of the tip 120. As with the
forward
projecting lateral surface 152, a flush interface between an outer surface 160
of the downwardly
extending pprtion 130 and an outer surface 162 of the backward lateral side
156 prevents debris
from wedging between the tip 120 and base 140 when the backward lateral side
I56 pushes
against the ground.
[0028] While any suitable material known to one skilled in the art would be
suitable for
the base 140, extruded aluminum is preferred because of its resistance to
corrosion, lightness,
and aesthetic appeal. Other materials containing aluminum are also preferable.
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[0029] To reduce the weight and expense (of manufacture) of the base 140, a
longitudinal through-hole 164 may be provided in the base 140. Unlike the open
inside 302 of
the conventional "U" shaped crosspiece 3f30, the longitudinal through-hole 164
is not open to the
environment in the vertical and lateral directions (or a direction
perpendicular to the longitudinal
axis) and therefore prevents debris from accumulating therein.
[0030] Hereinafter, the connection between the tip 120, base 140, and track 6
will be
described with reference to FTGS. 6 and 7. The bands 8 of the track 6 are
provided with vertical
through-holes 166 that align with the vertical through-holes 12;4, 142 of the
tip 120 and base 140;
respectively, when the crosspiece 100 is properly positioned on the track 6. A
bolt 168 extends
through each set of through-holes 124, 142, 166 in the tip 120, base 140, and
track 6,
respectively, to securely fasten both the tip 120 to the base 140 and the base
140 to the track 6.
The dual use of each bolt 168 advantageously reduces the number of components
of each
crosspiece 100 relative to conventional two-piece crosspieces :~20, 430 that
use separate bolts to
attach the tip to he base and the base to the track.
[0031] Preferably, the bolt 168 is fed upwardly through the through-holes 124,
142, 1G6
from an inside surface 6b of the track such that each nut 170 is attached to
each bolt 168 above
the base 140. Because each nut 170 is accessible from a direction
perpendicular to the
longitudinal axis, each nut 170 is easily removable. Consequently, tips 120
andlor bases 140 can
be easily replaced. The use of a nut 170 also improves upon conventional
crosspieces that utilize
internally threaded holes, instead, because such conventional crosspieces are
more expensive to
manufacture and quickly wear if the crosspiece is aluminum.
[0032) Because the bolt 168 that attaches the base I40 to the tip 120 extends
vertically,
not horizontally as in the conventional two-piece crosspieces 320, 430, the
narrow top 128 of the
tip 120 is not disadvantageously widened. Consequently, the narrow top 228 of
the crosspiece
100 of the present invention can more effectively penetrate the ground.
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[0033] FIG. 8 illustrates a cross-sectional view of a crosspiece 200 according
to a second
embodiment of the present invention, which is generally similar to the
crosspiece 100. However,
several differences are noted below.
[0034] The tip 220 according to the second embodimeW differs from the tip 120
of the
first embodiment in that the tip 220 does not include the downwardly extending
portion 130 that
the tip 120 of the first embodiment includes.
[0035] The base 240 of the second embodiment differs from the base 140 of the
first
embodiment in several aspects. First, the outer surface 262 and longitudinal
through-hole 264 of
the base 240 is generally more rounded than in the first embodiment. Second,
because the tip
220 does not include a downwardly extending portion lie the downwardly
extending portion
130 in the first embodiment, a corresponding mating recess in the base 240 is
not used. Third,
the base 240 does not include an upwardly pmj ecting portion Like the upwardly
proj ectixxg
portion 150 in the first embodiment. While the absence of downwardly and
upwardly projecting
portions in the base 240 of the second embodiment may disadvantageously allow
debris to
wedge between the tip 220 and base 240, the construction is sinzpli$ed with
respect to the
embodiment illustrated in F1G. 7.
[0036] While the invention t~s been d~eseribed with reference to two sp~ific
preferred
embodiments, it will be understood by those skilled in the art that various
changes may be made
and equivalents may be substituted for elements thereof without departing from
the spirit and
scope of the present invention. For example, any combination of the specif c
aspects identified
in the embodiments may be utili2ed without departing from the scope of the
present invention.
In addition, many modifications may be made to adapt a particular situation,
componem, or
material to the teachings ofthe present invention without departing from its
teachings as
claimed.
