U.S. patent number 3,711,164 [Application Number 05/122,337] was granted by the patent office on 1973-01-16 for snowmobile slide rail suspension.
This patent grant is currently assigned to Poly-Traction Inc.. Invention is credited to Guy-Noel Chaumont.
United States Patent |
3,711,164 |
Chaumont |
January 16, 1973 |
SNOWMOBILE SLIDE RAIL SUSPENSION
Abstract
The disclosure herein describes a slide rail for use in a
snowmobile-type suspension assembly; the rail consists of an
elongated member with a bottom wall and two side walls. Each side
wall is provided with a pair of longitudinally spaced slots, one
slot of one side wall being transversely aligned with a slot of the
other side wall. The elongated member is mounted to a bearing shaft
transversely extending beneath the vehicle, by means of separate
link members with one end pivotally mounted on the shaft and with
the other end adjacent the slots, of fastening members extending
through the slots and securing the lower ends of the link members,
and of torsion spring means which are supported on the bearing
shaft and include end portions in yielding engagement with link
members disposed fore and aft relative to the bearing shaft and
urging the link members in a downward direction to thereby cause
the rail to maintain contact pressure on the lower run of the
track.
Inventors: |
Chaumont; Guy-Noel
(Tring-Jonction, Quebec, CA) |
Assignee: |
Poly-Traction Inc.
(Tring-Jonction, Quebec, CA)
|
Family
ID: |
22402127 |
Appl.
No.: |
05/122,337 |
Filed: |
March 9, 1971 |
Current U.S.
Class: |
305/127; 180/193;
305/168 |
Current CPC
Class: |
B62D
55/108 (20130101); B62M 2027/026 (20130101) |
Current International
Class: |
B62D
55/104 (20060101); B62D 55/108 (20060101); B62d
055/10 (); B62m 027/02 () |
Field of
Search: |
;180/5
;305/17,18,24,25 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Johnson; Richard J.
Claims
What I claim is:
1. A slide rail suspension assembly for mounting on a bearing shaft
transversely extending beneath a snowmobile-type vehicle driven by
an endless track having upper and lower vertically spaced runs
comprising, in combination:
a. an elongated rail member longitudinally extending beneath the
bearing shaft and contacting the lower run of the track, said rail
having a bottom wall and two opposite upwardly extending side
walls, each of said side walls provided with a pair of
longitudinally spaced slots disposed fore and aft relative to the
bearing shaft, one slot of one side wall being transversely aligned
with a slot of the other side wall;
b. separate link members each having one end pivotally mounted on
the bearing shaft and the other end disposed adjacent said
slots;
c. fastening members extending through transversely aligned slots
and securing the lower end of said link members to said rail;
d. torsion spring means supported on said bearing shaft and
including end portions in yielding engagement with link members
disposed fore and aft the bearing shaft and urging the link members
in a downward direction thereby causing said rail to maintain
contact pressure on the lower run of the track.
2. A slide rail suspension assembly as defined in claim 1 wherein
said bottom wall and said side walls define a first lengthwise
channel; further comprising a pair of wear-resistant slide members,
each slide member being received in said channel adjacent a pair of
transversely aligned slots; each slide member supporting one of
said fastening members so as to prevent said fastening members to
contact the edges of said slots and to prevent said fastening
members to become jammed transversely in said slots.
3. A slide rail suspension assembly as defined in claim 2 wherein
the side walls of said channel further include inwardly bent flange
portions extending at least partially over said slide members
thereby confining said slide members in said channel.
4. A slide rail suspension as defined in claim 3 wherein said rail
further includes two downwardly extending side walls defining with
said bottom wall a second lengthwise channel, and a longitudinal
wear-resistant runner tightly received in said second channel and
having an underside adapted to contact the lower run of the
track.
5. A slide rail suspension assembly as defined in claim 4 wherein
the separate link members are mounted in pairs fore and aft
relative to the bearing shaft and wherein the end portions of said
torsion spring means engage one link member of each pair of link
members.
6. A slide rail suspension as defined in claim 4 wherein said slide
members and said longitudinal wear-resistant runner are made of
nylon.
7. In a snowmobile-type vehicle having a body structure and being
driven by an endless track having upper and lower vertically-spaced
runs, in combination:
I. two or more longitudinally spaced bearing shafts transversely
extending beneath the vehicle and having their opposite ends
secured to the body structure;
Ii. one or more slide rail suspension assemblies mounted on each of
said bearing shafts, each assembly comprising:
a. an elongated rail member longitudinally extending beneath the
bearing shaft and contacting the lower run of the track, said rail
having a bottom wall and two opposite upwardly extending side
walls, each of said side walls provided with a pair of
longitudinally spaced slots disposed fore and aft relative to the
bearing shaft, one slot of one side wall being transversely aligned
with a slot of the other side wall;
b. separate link members each having one end pivotally mounted on
the bearing shaft and the other end disposed adjacent said
slots;
c. fastening members extending through transversely aligned slots
and securing the lower end of said link members to said rail;
d. torsion spring means supported on said bearing shaft and
including end portions in yielding engagement with link members
disposed fore and aft the bearing shaft and urging the link members
in a downward direction thereby causing said rail to maintain
contact pressure on the lower run of the track.
8. In a snowmobile-type vehicle as defined in claim 7, wherein two
slide rail suspension assemblies are mounted on each bearing shaft
in laterally spaced relationship, the slide rail suspension
assembly on one bearing shaft being in longitudinal alignment with
the slide rail suspension assembly on a longitudinally spaced
bearing shaft, said suspension assemblies in alignment being
interconnected at one of their ends in an articulated relationship
whereby each rail may individually and independently pivot about
its bearing shaft.
9. In a snowmobile-type vehicle as defined in claim 8, wherein the
foremost slide rails have an upturned inclined front portion and
wherein the foremost link members on said foremost slide rails
support a wheel carrying shaft.
10. A slide rail for use in a snowmobile-type suspension assembly
comprising an elongated member having a bottom wall and two
opposite upwardly extending side walls, each of said side walls
provided with a pair of longitudinally spaced slots, one slot of
one side wall being transversely aligned with a slot of the other
side wall, said elongated member further including two downwardly
extending side walls defining with said bottom wall a lengthwise
channel, a longitudinal wear-resistant runner being secured in said
channel and having an underside extending beyond the downwardly
extending side walls.
11. A slide rail as defined in claim 10 wherein each of said
upwardly and downwardly side walls include inwardly bent flange
portions at their upper and lower edges, respectively.
12. A slide rail as defined in claim 11 wherein one end of said
member has an upturned inclined portion and wherein the other end
is adapted to be connected to another like elongated member.
Description
This invention relates generally to a suspension assembly for use
in a lightweight vehicle of the type driven by an endless flexible
track. More particularly, this invention relates to an improvement
in the construction of a suspension assembly for a snowmobile or
the like using slide bars or rails to apply contact pressure on the
inner surface of the lower run of the track.
Most present-day snowmobile suspension assemblies normally consist
of an arrangement of a plurality of bogey wheels which are
downwardly spring biased so as to be in constant rolling contact
with the inner surface of the ground-engaging run of the track.
More recently, a further suspension assembly (see, for examples,
U.S. Pat. No. 3,527,505 and U.S. Pat. No. 3,527,506, both issued on
Sept. 8, 1970 to A. E. Hetteen and A. R. Erickson, respectively)
has been devised wherein one or more longitudinally extending rails
slide on the inner surface of the track; this type of slide rail
suspension, however, is normally combined with a bogey wheel type
of suspension to provide maximum traction to the driving track.
It has been found that the manner in which slide rails are mounted
to the body structure of the vehicle in order to maintain the lower
run of the track in full driving engagement with the snow or ice is
quite complex and requires a considerable number of parts thereby
increasing the occurrence of breakdown due to component
failure.
It is an object of this invention to provide an improved suspension
assembly for track-propelled vehicles using longitudinally
extending slide rails, the mounting of which to the body structure
of the vehicle is simple and effective while providing to the upper
part of the vehicle the necessary resilient action.
According to the present invention, there is provided an improved
slide rail for use in a snowmobile-type suspension assembly
comprising an elongated member having a bottom wall and two
opposite upwardly extending side walls; each side wall is provided
with a pair of longitudinally spaced slots, one slot of one side
wall being transversely aligned with a slot of the other side wall.
The elongated member is mounted to a bearing shaft transversely
extending beneath the vehicle by means of separate link members
which have one end mounted on the bearing shaft and the other end
adjacent the slots, of fastening members which extend through the
slots and secure the lower end of the link members to the rail, and
of torsion spring means which are supported on the bearing shaft
and include end portions in yielding engagement with link members
disposed fore and aft the bearing shaft and urging the link members
in a downward direction thereby causing said rail to maintain
contact pressure on the lower run of the track.
In a particularly advantageous embodiment of the present invention,
the fastening members are supported by nylon sliding members
resting on the bottom wall of the rail; these sliding members
maintain the fastening members transversely to the slots and also
prevents the fastening members from wearing the edges of the
slots.
In another preferred embodiment of the invention, two slide rails
are positioned in longitudinal alignment on the lower run of the
track and are interconnected at one of their ends in an articulated
relationship to provide optimum contact pressure by the rails on
the lower run of the track and to enable the track to more closely
follow the conformation of the terrain over which the vehicle
travels.
In order that the invention may be readily understood, a preferred
embodiment thereof will now be described, by way of example, with
reference to the accompanying drawings in which:
FIG. 1 is a side elevational view of the lower portion of a vehicle
embodying the present invention with the body of the vehicle partly
cut away;
FIG. 2 is a fragmentary enlarged side elevational view showing two
slide rails in an articulated relationship;
FIG. 3 is a longitudinal top plan view taken along lines 3--3 of
FIG. 1;
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 3;
and
FIG. 5 is a transverse cross-sectional view taken along lines 5--5
of FIG. 3.
Referring generally to the drawings, there is shown the lower
portion of a snowmobile-type vehicle consisting of the two lateral
side walls 10 and 12 of an inverted U-shaped body structure 14. The
vehicle is driven by means of an endless flexible track 16 which is
looped around a drive sprocket wheel 18, journalled on the front
axle 20, and around one or more idler sprocket wheels 22, mounted
on the rear axle 24. Also mounted on the front axle 20 are a pair
of track support wheels 26 disposed on opposite sides of the drive
sprocket wheel 18. In the present case, only one track is shown
mounted underneath the vehicle but it is well known in the
snowmobile art that some vehicles are equipped with a pair of
laterally spaced drive tracks. The loop divides the track into an
upper run 28 and a lower run 30, vertically spaced from one
another; the lower run has a ground-engaging corrugated outer
surface 32 and an inner generally flat surface 34. The track 16
shown consists of four elongated strips of elastomeric material 35,
36, 37 and 38 longitudinally extending of the vehicle; the strips
are laterally spaced by three rows of aligned
sprocket-teeth-receiving openings 40, 41 and 42. The strips are,
however, held in spaced relation by means of a plurality of
transversely extending reinforcing members (not shown) which may be
partially or entirely embedded in the elastomeric material. An
example of such a track is described in applicant's co-pending
Canadian application Ser. No. 104,072 filed Jan. 29, 1971. At the
level of the rows of openings, the reinforcing members support for
rotation thereabout rollers 44; the typical construction and
operation of such track is disclosed in applicant's co-pending
Canadian application Ser. No. 104,073 filed Jan. 29, 1971. Some
other tracks are provided with a wearing metal clip crimped around
the rubber material between adjacent openings.
Referring to FIGS. 1, 2 and 3, an example of a suspension assembly
made in accordance with the present invention is shown mounted on a
plurality of transversely extending and longitudinally spaced
support members 44 disposed between the lateral side walls 10 and
12 of the body structure 14. Each support member 44 consists of a
bearing shaft 46 which is secured at its opposite ends to side
plates 48 and 50, respectively fixed to side walls 10 and 12 by
means of bolts 52 and 53. Each bearing shaft carries two sets 56 of
separate link members; the sets are equidistantly disposed on each
side of the longitudinal central axis of the vehicle and are
separated from one another by a sleeve 57 coaxially mounted on the
shaft 46. Each set 56 consists of four link members 59, 60, 61 and
62 which have their upper ends pivotally mounted on shaft 46 and
their lower end disposed adjacent an elongated rail 66
longitudinally extending beneath the bearing shaft and contacting
the lower run 30 of the track 16. The slide rail 66 is formed of
any suitable rigid material, preferably extruded aluminum and
consists of a bottom wall 68, a first pair of opposite upwardly
extending side walls 70 and 72, and a second pair of opposite
downwardly extending side walls 74 and 76 thereby forming a
substantially H-shaped frame member (see FIG. 5). Side walls 70 and
72 have inwardly bent upper flange portions 78 and 80 and define
with the bottom wall 68 a first lengthwise channel 73 (see FIG. 3)
which receives a pair of slide members 82 and 100 of any suitable
wear-resistant material, such as nylon. Side walls 74 and 76 have
inwardly bent lower flange portions 84 and 86 and define with the
bottom wall 68 a second lengthwise channel in which is fixedly
received a longitudinal runner 85 of any suitable wear-resistant
material, such as nylon. The runner 85 extends beyond the flange
portions 84 and 86 and has an underside with a recess 87 in which
are received for rotation the rollers 44 of the track 16; this type
of rail-and-roller construction greatly diminishes the wear of the
track due to frictional contact or the occurrence of clip
de-crimping.
Side walls 70 and 72 are each provided with a pair of
longitudinally spaced slots 88 and 90 disposed fore and aft
relative to the bearing shaft 46, one slot of one side wall being
transversely aligned with a like numbered slot of the other side
wall. Slide members 82 and 100 are respectively received in channel
73 adjacent a pair of transversely aligned slots 88 and 90 and
respectively support fastening members, such as bolts 94 and 98.
Referring to FIG. 5, bolt 94 has a shank portion 92 which extends
through the slide member 82; bolt 94 secures the lower end of link
members 59 and 61 to the rail 66. In order to ensure that the shank
portion of the bolt will not unduly wear the edges of slots 88, the
slide member 82 is constructed to receive bolt 94 so as to leave a
clearance between the bolt and the edges of the slots. Furthermore,
the function of the slide members 82 and 100 is to maintain the
transverse bolt 94 perpendicular to the longitudinal axis of the
rail thereby preventing the jamming of the bolt in the slots.
In order to yieldingly urge the link members in a downward
direction to thereby cause the rails to maintain contact pressure
on the lower run of the track, torsion spring means 102 are
supported by the bearing shaft 46 and include end portions 104 and
106 in engagement with one link member disposed fore the bearing
shaft and with one link member disposed aft the bearing shaft. The
link members are mounted in pairs; however, since the link members
of each pair are interconnected by the fastening members, the
torsion springs 102 need only have one end in contacting engagement
with each side of the bearing shaft.
The invention has been described above in relation to a suspension
assembly mounted on one bearing shaft and with particular reference
to the drawings wherein two longitudinally spaced shafts 44 carry
two suspension assemblies equidistantly disposed on either side of
the longitudinal axis of the vehicle. However, persons versed in
this art will be aware that the present suspension assembly may be
adapted to be mounted on vehicles having a different number of
shafts or having a different track construction.
In another advantageous embodiment of the present invention, as
shown in FIG. 3, the slide rail suspension assembly mounted on one
bearing shaft is disposed in longitudinal alignment with the slide
rail suspension assembly mounted on the next longitudinally spaced
bearing shaft. The two aligned rails 66 are interconnected in an
articulated manner by having one of their ends pivotally connected
by means of a pin or bolt 108; thus each rail may individually and
independently pivot about its bearing shaft and the track may more
closely follow the conformation of the terrain over which the
vehicle runs.
Referring to FIGS. 1-3, the foremost slide rails 66 have an
upturned inclined front portion 118 and the foremost link members
(60 and 62) on these foremost slide rails support a shaft 112
carrying wheels 114 and 116. This arrangement of upturned front
portions and of wheels assists the track in sliding under the
rails.
Although the invention above has been described in relation to one
specific form of the invention, it is evident that, as mentioned
above, it can be refined and modified in various ways. It is
therefore wished to have it understood that this invention is not
limited in interpretation except by the terms of the following
claims.
* * * * *