U.S. patent application number 11/020227 was filed with the patent office on 2005-05-19 for spindle for convertable ski stance.
This patent application is currently assigned to Bombardier Recreational Products Inc.. Invention is credited to Cote, Mario, Lemieux, Rene, Mallette, Bertrand.
Application Number | 20050103547 11/020227 |
Document ID | / |
Family ID | 23188484 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050103547 |
Kind Code |
A1 |
Mallette, Bertrand ; et
al. |
May 19, 2005 |
Spindle for convertable ski stance
Abstract
A snowmobile is described having a frame with left and right
sides with left and right suspension assembly disposed thereon.
Left and right spindles are connected to the left and right
suspension assemblies. A left ski is pivotally attached to the left
spindle and a right ski is attached to the right spindle. Rotation
of the left and right spindles alters the ski stance of the
snowmobile. The stance may also be altered in other ways, which are
also disclosed.
Inventors: |
Mallette, Bertrand;
(Rock-Forest, CA) ; Lemieux, Rene; (Granby,
CA) ; Cote, Mario; (Bedford, CA) |
Correspondence
Address: |
BOMBARDIER RECREATIONAL PRODUCTS INC
INTELLECTUAL PROPERTY DEPT
PO BOX 230
NORTON
VT
05907-0230
US
|
Assignee: |
Bombardier Recreational Products
Inc.
Valcourt
CA
|
Family ID: |
23188484 |
Appl. No.: |
11/020227 |
Filed: |
December 27, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11020227 |
Dec 27, 2004 |
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|
10189578 |
Jul 8, 2002 |
|
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6860352 |
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60307155 |
Jul 24, 2001 |
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Current U.S.
Class: |
180/190 |
Current CPC
Class: |
B62M 27/02 20130101;
B62M 2027/026 20130101 |
Class at
Publication: |
180/190 |
International
Class: |
B62M 027/00 |
Claims
What is claimed is:
1. A method of altering a ski stance of a snowmobile, the
snowmobile including a frame having a right side and a left side,
an engine, an endless track connected to the engine, right and left
suspension assemblies pivotally connected to right and left sides
of the frame respectively, right and left spindles rotatably
connected to the right and left suspension assemblies respectively,
each spindle having an axis of rotation when connected to the
respective suspension assembly, and a right ski attached to the
right spindle and a left ski attached to the left spindle, the
method comprising the steps of: disconnecting the right ski from
the right spindle; disconnecting the left ski from the left
spindle; rotating the right spindle by approximately 180.degree.;
rotating the left spindle by approximately 180.degree.;
reconnecting the right ski to the right spindle; and reconnecting
the left ski to the left spindle.
2. A method of altering a ski stance of a snowmobile, the
snowmobile including a frame having a right side and a left side,
an engine, an endless track connected to the engine, right and left
suspension assemblies pivotally connected to right and left sides
of the frame respectively, right and left spindles rotatably
connected to the right and left suspension assemblies respectively,
each spindle having an axis of rotation when connected to the
respective suspension assembly, and a right ski attached to the
right spindle and a left ski attached to the left spindle, the
method comprising the steps of: disconnecting the right ski from
the right spindle; disconnecting the left ski from the left
spindle; rotating the right spindle by approximately 180.degree.;
rotating the left spindle by approximately 180.degree.;
reconnecting the right ski to the left spindle; and reconnecting
the left ski to the right spindle.
3. A method of altering a ski stance of a snowmobile, the
snowmobile including a frame having a right side and a left side,
an engine, an endless track connected to the engine, right and left
suspension assemblies pivotally connected to right and left sides
of the frame respectively, right and left spindles rotatably
connected to the right and left suspension assemblies respectively,
each spindle has an axis of rotation when connected to the
respective suspension assembly in an initial orientation, and a
right ski attached to the right spindle and a left ski attached to
the left spindle, the method comprising the steps of: disconnecting
the right spindle from the right suspension assembly; disconnecting
the left spindle from the left suspension assembly; reconnecting
the right spindle to the left suspension assembly while being kept
in the initial orientation; and reconnecting the left spindle to
the right suspension assembly while being kept in the initial
orientation.
4. The method of claim 3, further comprising the steps of:
disconnecting the right ski from the right spindle; disconnecting
the left ski from the left spindle; reconnecting the right ski to
the left spindle; and reconnecting the left ski to the right
spindle.
Description
[0001] This application is a divisional of U.S. application Ser.
No. 10/189,578, filed on Jul. 8, 2002. Through Ser. No. 10/189,578,
this application relies for priority on U.S. Provisional
Application No. 60/307,155, filed on Jul. 24, 2001, the entirety of
both applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention concerns the construction of a spindle to
which a ski of a snowmobile is attached. In particular, this
invention encompasses a spindle construction that facilitates
adjustment of the width of the ski stance for a snowmobile (also
known as a "sled").
[0004] 2. Description of Related Prior Art
[0005] In the prior art, there are at least two known types of
skis. The first is called a single-keel ski because it incorporates
a single keel having a single or double carbide runners, which runs
along a longitudinal part of the length of the underside of the
keel. The second conventional ski is called the dual-keel ski
because it incorporates a pair of keels which have carbide runners
that extend along longitudinal portions of the undersurface of the
snowmobile ski at positions laterally disposed apart from one
another. For the second type of ski, the two runners typically are
disposed one each on the two lateral edges of the keels.
[0006] Most snowmobiles that have been made in the last twenty
years have included two skis at the front for turning the vehicle.
The ski stance for snowmobiles is determined as the distance (or
width) between the two skis. In particular, where a snowmobile is
provided with a pair of single-runner skis, which is the more
common example to date, the ski stance is measured as the distance
(or width) between the carbide runners at the bottoms of the skis.
In the case of a snowmobile fitted with a pair of dual-runner skis,
the stance is measured as the distance between the centerlines of
the skis (or some other suitable convention).
[0007] Conventionally, snowmobiles are manufactured with a pre-set
ski stance. Depending on the type of terrain in which the
snowmobile is used, the pre-set ski stance may have either a
positive or a negative effect on the performance of the
snowmobile.
[0008] As a general rule, there are two basic types of riding
conditions for snowmobiles. Each of these two riding conditions
places different demands on the snowmobile. Accordingly, each
requires a different ski stance.
[0009] The first type of riding condition is the groomed trail.
Groomed trails include a base of compacted snow, generally with a
layer of loose snow above the compacted snow. Because the groomed
trail has a solid, compacted base layer, the carbide runners on the
bottoms of the snowmobile skis are generally always in contact with
the compacted surface. The carbide runners, therefore, provide the
edge upon which a turn may be executed. For maximum stability of
the snowmobile on a groomed trail, the ski stance is usually
pre-set to the widest distance possible. The maximum width of the
snowmobile, set by SSCC (Snowmobile Safety Certification
Committee), a safety group in the United States, is 48 inches.
Generally, the maximum width is set so that snowmobiles do not
interlock skis when passing one another on groomed trails.
[0010] The second type of riding condition, which is antithetical
to the first, is mountain terrain. Mountain snowmobiling differs
considerably from snowmobiling on groomed trails because the snow
is generally loose, powder snow, which is often deeper than the
height of the skis. In other words, in mountain conditions, the
bottoms of the skis almost never touch the ground. Therefore, the
carbide runners do not assist in turning the vehicle as much as
when on groomed trails.
[0011] In mountain snowmobiling, it is the preferred practice to
keep the ski stance to the smallest width possible. A small ski
stance facilitates side hilling of the snowmobile. Side hilling is
a technique used by mountain snowmobilers to climb the side of a
mountain. The technique requires riders to traverse the mountain
diagonally, thus, requiring riders to lean the snowmobile into the
surface of the mountain to keep the snowmobile in a substantially
horizontal position while crisscrossing the selected mountain area.
In order to facilitate leaning of the snowmobile, it is preferred
to decrease the distance between the ski and the frame (also
referred to as the "tunnel") of the snowmobile. This decreases the
moment applied to the snowmobile by the ski. It also permits the
snowmobile to get closer to the side of the mountain. In mountain
snowmobiling, snowmobiles usually traverse wooded areas. Therefore,
a narrow ski stance is particularly advantageous, because riders
may pass more easily between trees and other obstacles not
encountered on groomed trails.
[0012] Since the stances for mountain and trail riding conditions
are so different from one another, manufacturers currently
manufacture different snowmobiles specifically tailored to the
specific environment in which they are to be used. Groomed trail
snowmobiles are manufactured with the widest stance permissible by
the SSCC in order to maintain maximum stability. Mountain
snowmobiles, on the other hand, are manufactured with as narrow a
stance as possible to facilitate side hilling and also retain the
necessary balance of the vehicle while riding.
[0013] Because the two types of snowmobiles have such different
stances, the average consumer faces a dilemma when purchasing a
snowmobile. Purchasers who desire a snowmobile that will handle
optimally both on groomed trails and on mountain terrain will not
find such a vehicle commercially available. In addition, purchasers
located in areas where there is significant snowfall and few
trails, while they may require a mountain snowmobile to navigate
local conditions, may not desire a snowmobile designed specifically
for climbing hills and mountains. For consumers that live in heavy
snowfall areas and do not necessarily engage in mountain climbing
but do engage off-trail riding, a higher degree of stability can be
achieved by increasing the narrow stance of a conventional mountain
sled.
[0014] One way to alter the ski stance of a conventional snowmobile
is to increase or decrease the distance between the frame and the
spindle holder by altering the length of the lower arm assembly and
the upper arm assembly, both of which attach the spindle holder to
the frame. Although this alters the ski stance of the snowmobile,
such a modification requires realignment of the steering rod and
the stabilizer bar. This modification also necessitates
readjustment of the shock assembly because of the many parts that
individually connect to the arm at a predetermined distance from
the frame.
[0015] As will be appreciated by those skilled in the art, while it
is possible to modify a snowmobile's stance, it is not possible to
do so at present without significant effort.
[0016] A need has, therefore, arisen for a snowmobile ski spindle,
which offers a quick and easy way to convert a snowmobile's ski
stance without having to re-adjust other parameters of the
snowmobile's front suspension system.
SUMMARY OF THE INVENTION
[0017] It is, therefore, an aspect of the present invention to
provide an improvement upon the current design for a snowmobile
spindle arrangement.
[0018] According to one aspect of the present invention, the
spindle facilitates altering the stance of a snowmobile without
having to significantly rework or replace the snowmobile's
suspension.
[0019] It is another aspect of the present invention to provide
spindle for a snowmobile having an upper portion which defines an
axis of rotation and a lower portion which defines a pivot axis,
wherein the axis of rotation is offset from the midpoint of the
lower portion.
[0020] Yet another aspect of the present invention is to provide a
spindle having removable spacer. The removable spacers can be
placed on the right or left side of the spindle to create an offset
to the side on which the spacer is attached.
[0021] It is another aspect of the present invention to provide a
snowmobile with a spindle, which can be rotated to alter the ski
stance.
[0022] It is yet another aspect of the present invention to provide
a snowmobile with a spindle, which can be placed on the opposite
side of the snowmobile to alter the ski stance. In other words, one
aspect of the present invention is to provide a snowmobile with
interchangeable spindles.
[0023] It is still yet another aspect of the present invention to
provide a snowmobile with a ski including a symmetrical axis,
wherein the axis or rotation of the spindle is offset from the
symmetrical axis of the ski.
[0024] It is another aspect of the present invention to provide a
snowmobile with a ski including a runner having a longitudinal axis
attached to the underside of the ski, wherein the axis of rotation
of the spindle is offset from the longitudinal axis of the
runner.
[0025] Other aspects of the present invention will be made apparent
from the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] As would be recognized by one skilled in the art, a
snowmobile has a front, a left side, and right side and a rear when
viewed by an individual sitting on the vehicle facing the direction
of vehicle travel. Where reference is made to one side of the
vehicle, it is to be assumed the opposite side is its mirror image
unless otherwise specified.
[0027] Reference will be made hereinafter to the accompanying
drawings, which illustrate embodiments of the present invention
discussed herein below, wherein:
[0028] FIG. 1 is a left side schematic view of a first conventional
snowmobile manufactured by Bombardier Inc., of Montreal, Quebec,
Canada;
[0029] FIG. 2 is an exploded, perspective illustration of the front
suspension typically included on the snowmobile illustrated in FIG.
1;
[0030] FIG. 3 is a front view of the spindle conventionally
included in the front suspension illustrated in FIG. 2;
[0031] FIG. 4 is a left front perspective view of a second
conventional snowmobile, called the "Elan," manufactured by
Bombardier Inc., of Montreal, Quebec, Canada;
[0032] FIG. 5 is an exploded, perspective view of the typical
spindle and ski arrangement included on the snowmobile illustrated
in FIG. 4;
[0033] FIG. 6 is an exploded view of the spindle illustrated in
FIG. 5, shown together with elements, of the steering mechanism for
the conventional snowmobile illustrated in FIG. 4;
[0034] FIG. 7 is a front view of a first embodiment of the spindle
of the present invention;
[0035] FIG. 8 is a perspective side view of the spindle illustrated
in FIG. 7;
[0036] FIG. 9 is a cross-sectional view of a first orientation of a
first variation of the first embodiment of the present invention,
shown installed on the front suspension of a snowmobile together
with a first variation of a pair of skis attached thereto;
[0037] FIG. 10 is a cross-sectional view of a second orientation of
the first embodiment of the present invention, shown installed on
the front suspension of a snowmobile with the first variation of
the skis attached thereto;
[0038] FIG. 11 is a cross-sectional view of a first orientation of
the first embodiment of the present invention, shown installed on a
snowmobile with a second variation of skis attached thereto;
[0039] FIG. 12 is a cross-sectional view of a second orientation of
the first embodiment of the present invention, shown installed on a
snowmobile with a second variation of skis attached thereto;
[0040] FIG. 13 is a front view of a second embodiment of the
spindle of the present invention;
[0041] FIG. 14 is a front view of a ski leg according to a third
embodiment of the present invention;
[0042] FIG. 15 is a left side view of the ski leg illustrated in
FIG. 14;
[0043] FIG. 16 is a front view of a first alternative embodiment of
the ski leg of the present invention;
[0044] FIG. 17 is a front view of a second alternative embodiment
of the ski leg of the present invention;
[0045] FIG. 18 is a left rear perspective view of a spacer of the
ski leg of the present invention;
[0046] FIG. 19 is a front, left perspective view of a double A-arm
type front suspension system, including the ski leg of the present
invention that is illustrated in FIG. 14; and
[0047] FIG. 20 is a left side view schematic illustration of a
third snowmobile according to the present invention, which is also
manufactured by Bombardier Inc. of Montreal, Quebec, Canada.
DETAILED DESCRIPTION OF THE INVENTION
[0048] Through out the description of the several embodiments of
the present invention, reference will be made to various elements,
the construction of which is readily known to those skilled in the
art. Accordingly, an exhaustive description of each and every
component is not provided, only description of those elements
required for an understanding of the present invention.
[0049] FIG. 1 illustrates a conventional snowmobile 10, which is
manufactured by Bombardier Inc. of Montreal, Quebec, Canada. While
only the left side of the snowmobile 10 is illustrated, those
skilled in the art would readily appreciate that the right side is
essentially a mirror image thereof.
[0050] The snowmobile 10 is constructed with a frame 12 powered by
a motor 14. The motor 14 preferably is an internal combustion
engine, which may be one of either the two-stroke or four-stroke
variety. Handlebars 16 are disposed above and to the rear of the
motor 14. The handlebars 16 are operatively connected to two skis
18, 20 disposed at the front of the snowmobile 10. When turned by
the handlebars 16, the skis 18, 20 turn the snowmobile 10 in the
desired direction.
[0051] The skis 18, 20 are suspended from a front suspension 22.
The front suspension 22 includes, among other components, two arms
24, one disposed on either side of the snowmobile 10. The arms 24
are connected to shock assemblies 26. To turn the skis 18, 20, the
handlebars 16 are connected thereto via a steering rod 28 or some
other suitable connector.
[0052] The motor 14 is operatively connected to an endless track 30
at the rear of the snowmobile 10 beneath the frame 12. The endless
track 30 propels the snowmobile 10 forward (or in reverse, as the
case may be).
[0053] So that the skis 18, 20 turn the snowmobile 10 effectively
as it is propelled forward by the endless track 30, the skis 18, 20
each are provided with one or more runners 32 (or wear bars). The
runners 32 extend along a portion of the undersides of the skis 18,
20 and come into contact with the ground. The runners 32 typically
are made of a wear-resistant material such as steel. To further
increase the wear-resistance of the runners 32, they are often
provided with carbide edges. Other constructions of the runners may
be used without departing from the scope of the present
invention.
[0054] As illustrated in FIG. 2, a spindle 34 connects to the left
ski 18 through a bridge 36. The bridge 36 typically is an elongated
U-shaped structure with a bottom portion 38 connected to two
upwardly extending side portions 40 and 42. The bottom portion 38
of the bridge 36 is adapted to fit onto the ski 18 and is held in
place with the studs 44 that are integrally connected to the runner
32. In the example illustrated, the studs 44 extend upwardly from
the runner 32, pass through the ski 18, and the bottom portion 38
of the bridge 36. The ski 18 is fastened between the bridge 36 and
the runner 32, and the three components remain connected to one
another via the bolts 46 that engage the studs 44.
[0055] As illustrated in FIG. 2, the side portions 40 and 42 of the
bridge 36 include holes 48 at essentially the same position on each
respective side. The spindle 34 connects to the bridge 36 via a
spacer 50, a bolt 52 and a nut 54. The spacer 50 extends through
the bottom portion of the spindle 34. The bolt 52 extends through
the spacer and the holes 48 and connects the bridge 36 and the
spindle 34 together. The spacer 50 is slightly longer in length
than the width of the bottom portion of the spindle 34 and is
disposed between the two side portions 40 and 42 of the bridge 36.
Accordingly, when tension is applied to the nut 54 and bolt 52, the
sides of the bottom portion of the spindle 34 do not come into
tight contact with the side portions 40 and 42 of the bridge 36 to
prevent rotation therebetween.
[0056] As also illustrated in FIG. 2, the spindle 34 and ski 18 are
attached to the snowmobile front suspension 22 via a spindle holder
56. The spindle holder 56 is attached at a forward portion of the
arm 24. The rear portion of the arm 24 is connected to the frame 12
via a pivot collar 58 and pin 60. Connecting the arm 24 to the
frame 12 of the snowmobile 10 in this manner serves at least two
functions. First, the pivot collar 58 permits the arm 24 to pivot
upwardly and downwardly, which allows the ski 18 to move up and
down as the snowmobile 10 traverses the ground. The pivot collar 58
also holds the ski 18 in a fixed relation to the frame 12 so that
the ski 18 does not move rearwardly during operation of the
snowmobile 10.
[0057] The forward portion of the arm 24, at the location of the
spindle holder 56, includes a bracket 62. The bracket 62 is
operatively connected to the frame 12 via upper and lower arm
assemblies 64 and 66. The upper and lower arm assemblies 64, 66
serve at least two functions. First, the upper and lower arm
assemblies 64, 66 permit the arm 24 to pivot about the pivot collar
58. This, in turn, permits the spindle 34 and ski 18 to move up and
down with respect to the frame 12. Second, the upper and lower arm
assemblies 64, 66 maintain the spindle 34 and ski 18 in a fixed
lateral position with respect to a centerline 68 of the snowmobile
10. In other words, the upper and lower arms 64, 66 prevent the ski
18 from collapsing laterally inward toward the centerline 68 of the
snowmobile 10 during operation.
[0058] To cushion the forces experienced by the ski 18 as it
traverses the ground (so that the forces are not transmitted to the
rider), a shock absorber 70 connects the bracket 62 to the frame
12. The shock absorber 70 ensures that the frame 12 remains
disposed above the ground. It also dampens any shocks encountered
when the snowmobile 10 encounters rough terrain.
[0059] As shown in FIG. 2, the stem 72 of the spindle 34 extends
vertically through the spindle holder 56. The stem 72 is rotatably
disposed within the spindle holder 56 and permits the spindle 34 to
turn relative to the centerline 68 of the snowmobile 10. The top of
the stem 72 extends above the top portion of the spindle holder 56.
The top of the stem 72 includes a serrated portion 90 that engages
with a steering arm 74. The steering arm 74, in turn, is connected
to a steering bar 76 that is operatively connected to the
handlebars 16.
[0060] An enlarged detail of the spindle 34 shown in FIG. 2 is
provided in FIG. 3. The spindle 34 includes a bottom bracket 78 and
a stem 72 extending upwardly therefrom. The stem 72 defines an axis
of rotation 80 along the longitudinal length thereof. The stem 72
and bracket 78 connect to a tubular member 82. The stem 72, bracket
78, and tubular member 82 are preferably made of a metallic
material, such as steel, aluminum, or the like. The stem and
tubular member 82 are shown with a circular cross-section.
[0061] As illustrated, the stem 72 connects to the tubular member
82 via a weld 84. Similarly, the bracket 78 connects to the tubular
member 82 via welds 86. The axis of rotation 80 of the stem 72 is
essentially perpendicular to the central axis 88 of the tubular
member. A serrated portion 90 is provided at the top of the stem 72
so that the stem may engage the steering arm 74. The number of
serrations is an odd number.
[0062] A second snowmobile 92 known in the prior art is illustrated
in perspective view in FIG. 4. The snowmobile 92 was manufactured
by Bombardier Inc. of Montreal, Quebec, Canada under the name
"Elan."
[0063] The snowmobile 92 includes a frame 94 powered by an engine
96 (shown schematically). The frame 94 includes a front suspension
98 from which left and right skis 100, 102 are suspended. An
endless track 104 is positioned beneath the frame 94 and is powered
by the engine 96. Handlebars 106 are positioned in front of a seat
108 and behind the engine 96. As in the previous snowmobile 10, the
handlebars 106 are operatively connected to the skis 100, 102 so
that, when the handlebars 106 are turned, the skis 100, 102 rotate
to turn the snowmobile 92.
[0064] FIG. 5 illustrates the ski 100 of the snowmobile 92 in
greater detail. The ski 100 has a forward end 110 and a rearward
end 112. The forward end 110 includes a handle 114. The handle 114
includes a bracket 116. At the rearward end 112 of the ski 100,
there is a second bracket 118. A leaf spring assembly 120,
comprising at least three stacked springs 122, 124, 126, extends
between the brackets 116, 118.
[0065] In this snowmobile 94, which is considerably older than the
snowmobile 10 illustrated in FIG. 1, there is no shock absorber to
cushion the forces experienced by the skis 100, 102 as the
snowmobile 92 traverses the ground. The leaf spring assembly 120
functions as the shock absorber for each side of the snowmobile
92.
[0066] As illustrated in FIG. 5, the leaf spring 122 includes an
eyelet 128 that is rotationally connected to the bracket 118 via a
pin 130. The pin 130 affixes the leaf spring 122 to the ski 100.
Since the leaf spring assembly 120 must be permitted to flex and,
therefore, absorb the force of obstacles encountered by the ski
100, the front end of the leaf spring assembly 120 is not connected
to the ski 100. Instead, the front end of the leaf spring assembly
120 is disposed beneath the pin 132 extending through the bracket
116 at the rear end of the handle 114. As the leaf spring assembly
120 compresses, the forward end of the assembly 120 slides forward
under the pin 132.
[0067] A bumper 134 is disposed beneath the leaf spring assembly
120. The bumper 134 connects to the leaf spring assembly 120
through the nut 136 and bolt 138 that extends below the guide plate
140, the leaf springs 122, 124, 126 and the bracket 142. The bumper
134 is a resilient member that is disposed above the indentation
144 in the ski 100. As the leaf spring assembly 120 expands and
contracts, the bumper 134 prevents the leaf spring assembly 120
from metal to metal contact with the ski 100.
[0068] The ski 100 includes a runner 146, much in the same way as
the ski 18 on the snowmobile 10. In this case, however, the ski 100
is preferably made from a metal such as steel. In addition, the
runner 146 attaches to the ski via a stud 148 connected thereto.
The stud 148 passes through the ski 100 and is connected thereto
via a bolt 150.
[0069] The bracket 142 is disposed at the top of the leaf spring
assembly 120. The bracket 142 is U-shaped and includes two holes
152. A spindle 154 connects to the bracket 142 so that the spindle
154 may rotate with respect thereto. The spindle includes a stem
156, a bottom portion 158, and a serrated top portion 160 with an
odd number of serrations.
[0070] The serrated top portion 160 of the stem 156 connects with a
steering arm (not shown) so that rotation of the handlebars 106
translates into rotation of the spindles 154 (and, accordingly, the
skis 100, 102). The bottom portion 158 of the spindle 154 provides
an offset connection between the axis 162 of the spindle 154 and
the longitudinal axis of the ski 100. This is necessary because the
frame 94 of the snowmobile 92 is disposed so close to the spindles
154 that an additional lateral distance is needed to ensure that
the skis 100, 102 move freely when actuated by the handlebars
106.
[0071] FIG. 6 illustrates the operative connection between the
spindle 154 and the handlebars 106. The spindles connect to a
steering arm 164 via the serrated top 160. The steering arm 164, in
turn, connects to a steering rod 166. The steering rod 166 is
connected, via a linkage 168, to the steering column 170. As shown,
the steering column 170 connects to the handlebars 106.
[0072] As discussed in the Background of the Invention, above, the
prior art does not include any way to conveniently modify the ski
stance for a snowmobile, whether snowmobile 10 or its predecessor,
snowmobile 92. For snowmobile 10, the axis 80 of the spindle 34 is
the same as the axis for the ski 18. Accordingly, nothing could be
done with the spindles 34 to alter the stance of the snowmobile
10.
[0073] The same is true for the snowmobile 94. While the bottom
portion 158 of the spindle 154 provided an offset for the ski 100,
the purpose of the offset was to dispose the skis 100, 102 a
slightly greater distance from the frame 94 than was possible with
the spindles 154 alone. This was necessary for the skis 100, 102 to
avoid hitting the frame 94 (or other parts of the snowmobile 92)
when turned by the handlebars 106. Changing the stance of the skis
100, 102 was not considered as a option at the time that snowmobile
94 was manufactured. Moreover, given the tolerances involved,
changing the ski stance was not possible on the snowmobile 92.
[0074] Swapping the spindles 154 on the right and left sides of the
snowmobile 92 for one another was not possible. As mentioned, the
bottom portions 158 of the spindles 154 provided for a wider ski
stance because the skis 100, 102 were disposed close to the frame
94. Accordingly, if the skis 100, 102 were swapped for one another,
the clearance problem would have been amplified. This would have
further interfered with the steerability of the snowmobile 92. This
result would have been antithetical to proper operation of the
snowmobile 92.
[0075] As mentioned above, a deficiency in the prior art lies in
the inability of the average consumer to modify the ski stance for
a snowmobile to convert the vehicle from groomed trail use to
mountain use (or deep powder use). The prior art offers no solution
to this problem.
[0076] The inventors realized that a simple solution to the problem
of an apparently inalterable ski stance lies in an alteration of
the design of the spindle on which the ski is disposed.
[0077] FIG. 7 illustrates a first example of an offset spindle 170
according to the present invention. The offset spindle 170 is
specifically designed to modify the stance of snowmobiles like that
of snowmobile 10.
[0078] The offset spindle 170 includes a stem 172 with a top
portion 174 and a bottom portion 176. The top portion 174 includes
an even number of serrations 178. The bottom portion 176 includes a
bracket 180 and a tubular member 182. The tubular member 182 is
connected to the bottom portion 176 via a weld 184. The tubular
member 182 is also connected to the bracket 180 via welds 186.
[0079] In the embodiment of the spindle 170 illustrated in FIG. 7,
the axis of rotation 188 of the stem 172 is offset from the
transverse centerline 190 of the tubular member 182. The transverse
centerline 190 of the tubular member 182 is the axis that coincides
with the centerline of the ski 100 on which the spindle 172 is
disposed when the ski is symmetrical. As illustrated, the axis of
rotation 188 of the stem 172 is disposed perpendicularly to the
axis 192 of the tubular member 182.
[0080] As discussed above, the top portion 174 of the stem 172
includes serrations (or splines) 178. The serrations 178 mate with
a steering arm, such as the steering arm 74 illustrated in FIG. 2.
Preferably, the top portion 174 includes an even number of splines
178 to permit rotation of spindle 170 by 180 degrees about the axis
of rotation 188. As would be appreciated by those skilled in the
art, without an even number of splines, rotation of the spindle 170
through 180 degrees about the axis of rotation 188 would not be
possible.
[0081] The connection of the bracket 180 to the tubular member 182
is such that the longitudinal axis 188 (or the axis of rotation
188), of the stem 172 is off set from the transverse centerline
190. Transverse centerline 190 is situated midway between the first
end 194 and the second end 196 of the tubular member 182. The first
end 194 and the second end 196 are placed between side portions of
a bridge such as that shown in FIG. 2. As known in the art, a
bridge such as that shown in FIG. 2 may not be necessary and the
first end 194 and the second end 196 may be placed between side
portion of the ski only. In the preferred embodiment, the axis of
rotation 188 is offset between about 0 to 25 mm from the transverse
centerline 190. Still more preferably, the offset is between about
5 to 20 mm. Most preferably, the offset is about 16 mm. The stem
172, bracket 180, and tubular member 182 are all preferably made of
steel. The stem 172 and tubular members 182 preferably have hollow
circular cross-sections. However, as would be appreciated by those
skilled in the art, the spindle 170 could be made with hollow or
solid members having non-circular cross-sections. Moreover, the
stem 172, bracket 180, and tubular member 182 may be made from any
other suitable material other than steel. For example, aluminum
could be substituted therefor without deviating from the scope of
the present invention. Also, stem 172 and member 182 could be one
integral part.
[0082] The bracket 180 provides structural rigidity to the
connection between the stem 172 and the tubular member 182. The
bracket 180 has an elongated inverted U-shape with holes 198, 200,
202 therethrough. The lower end 176 of the stem 172 passes through
hole 202 in the top of the bracket 180. The first end 194 of the
tubular member 182 passes through the hole 200 in the side of the
bracket. The second end 196 of the tubular member 182 passes
through the remaining hole 198. In the preferred embodiment, the
bracket 180 is made of steel. However, as one skilled in the art
would know, any suitable material could be used, as long as it is
compatible with the material used to construct the stem 172 and the
tubular member 182.
[0083] FIG. 8 provides a perspective illustration of the spindle
170 shown in FIG. 7. FIG. 8 provides additional information to
understand the construction of the spindle 170.
[0084] The operation of the spindle 170 will now be described in
connection with FIGS. 9-12, which illustrate the convertibility of
the ski stance, using two different skis as examples. FIGS. 9 and
10 illustrate the two possible stances for a snowmobile 10 fitted
with standard, single-keeled, groomed-trail skis 204, 206. FIGS. 11
and 12 show the two possible stances for a snowmobile 10 fitted
with mountain skis 208, 210. Skis 204, 206 differ from skis 208,
210 in several ways. One significant difference lies in the fact
that the skis 204, 206 may be placed on the right side or the left
side of the frame 220 without any undesirable consequences to
performance. This is due in part to the fact that the skis 204, 206
are symmetrical, and the runners 226 are positioned directly
beneath the spindles 172. The skis 208, 210, in contrast, are not
symmetrical. Thus, the skis 208, 210 must be installed in a
particular orientation to maximize performance of the snowmobile to
which they are attached. Preferably, the skis 208, 210 are
positioned so that the runners 228 remain on the outside of the
axis of rotation 188 of the stems 172 when operating the
vehicle.
[0085] For simplification, each of FIGS. 9-12 illustrates only
portions of the front suspensions 212, 214 on which the skis 204,
206 and 208, 210 are installed. The front suspensions 212, 214
share common elements. The illustrations of the front suspensions
212, 214 provide additional details of the front suspension 22
illustrated for snowmobile 10 depicted in FIG. 1.
[0086] In particular, the front suspensions 212, 214 include upper
arms 216 and lower arms 218 that are pivotally connected to a frame
220. Left and right spindle holders 222, 224 are disposed at the
lateral ends of the upper and lower arms 216, 218. The left and
right spindle holders 222, 224 retain the left and right spindles
172 therein. The spindles 172 are rotatable about the axes of
rotation 188. Shock absorbers 230 extend between the frame 220 and
brackets 232 that are connected to the spindle holders 222,
224.
[0087] Referring to FIGS. 9 and 10, the spindles 172 attach to skis
204, 206 in two different ways. FIG. 9 illustrates the first
orientation where the skis 204, 206 are oriented to have a narrow
stance. FIG. 10 illustrates the second orientation where the skis
204, 206 have a wide stance. Similarly, FIG. 11 illustrates a
narrow stance for the skis 208, 210 and FIG. 12 illustrates a wide
stance for the same skis.
[0088] As indicated above and as shown in FIGS. 9 and 10, the
spindle 172 is connected to the skis 204, 206 in two different
ways. FIG. 9 shows the spindles 172 connected to the skis 204, 206
on each side of the frame 220 such that the distance measured
between the runners 226 (known as the ski stance) is approximately
36 inches. As indicated above, this configuration is considered to
be a "narrow stance." FIG. 10 shows the spindles 170 connected to
the skis 204, 206 on each side of the frame 220 such that the
distance measured between the runners 226 is approximately 381/2
inches. This configuration is also known as the "wide stance." The
difference between the narrow stance shown in FIG. 9 and the wide
stance shown in FIG. 10 is equal to 4 times the distance "Y," which
is the desired off set between the axis of rotation 188 of the stem
172 and the transverse centerline 190.
[0089] Switching between the narrow stance and the wide stance with
the spindle 170 is very simple when using symmetrical skis, such as
the skis 204, 206. First, one detaches the spindles 172 from the
steering arms 234. Second, the skis 204, 206 are removed from the
spindles 172 by removing the nuts and bolts 236 at the bottoms of
the spindles 172. Third, the spindles 172 are rotated by 180
degrees about the axis of rotation 188 of the stems 172. Fourth,
the skis 204, 206 are reattached to the spindles 172 in the rotated
orientation. Performing these steps on the right and left sides of
the frame 220, replacing the nut and bolt 236, and reattaching the
steering arms 234, creates the wider stance, such as that shown in
FIG. 10.
[0090] The same process may be used to alter the stance of the skis
208, 210, as illustrated in FIGS. 11 and 12.
[0091] Alternatively, as would be appreciated by those skilled in
the art, in the case where the skis are symmetrical, such as skis
204, 206, the skis 204, 206 need not be detached from the spindles
172. Instead, the spindles 172 can be swapped from right to left
while the skis 204, 206 remain attached to the spindles.
[0092] Regardless of the symmetry of the ski used, the ski stance
can be altered to improve the characteristics of the snowmobile 10
shown in FIG. 1 without further modification to the components of
the suspension system.
[0093] FIG. 13 illustrates a second embodiment of the present
invention. In this drawing, the spindle 238 is constructed with a
stem 240 that is attached at the centerline of the tubular member
242 between the first and second ends 244, 246. In this embodiment,
the stem 240 includes an S-shaped bend 248 at a point along its
length between the top portion 250 and the bottom portion 252. The
S-shaped bend 248 has a radius of curvature r. Preferably, the
S-shaped bend 248 is closer to the bottom portion 252 than the top
portion 250 so that it does not interfere with turning of the
spindle 238 when installed on a snowmobile, such as the one
illustrated in FIG. 1.
[0094] As with the spindle 170 illustrated in FIGS. 7 and 8, the
bottom portion 252 of the spindle 238 is preferably connected to
the tubular portion 242 via a weld 254 (or some other suitable
connector). Similarly, the bracket 256 preferably is connected to
the tubular member via welds 258, 260. Of course, any other
suitable connector could be used instead. As with the previous
embodiment, the top portion 250 of the spindle 238 includes a
plurality of serrations 262.
[0095] As with the spindle 172 illustrated in FIGS. 7 and 8, the
bracket 256 preferably includes three holes to facilitate
attachment of the stem 240, tubular member 242 and the bracket 256
together. A first hole 264 is disposed through one side of the
bracket 256. A second hole 266 is disposed through the other side
of the bracket 256. A third hole 268 is disposed through the top
portion of the bracket 256.
[0096] The S-shaped bend 248 enables the axis of rotation 270 to be
offset from the transverse centerline 272 of the tubular member 242
so that the stance of the snowmobile may be adjusted to accommodate
specific riding conditions. As in the previous spindle 172, the
offset distance is illustrated as Y as is preferably within the
range of about 0 to 25 mm, more preferably within the range of
about 5 to 20 mm, and most preferably about 16 mm.
[0097] In the preferred embodiment of the spindle 238, the stem 240
is cylindrical in cross-section. This facilitates rotation of the
stem 240. The radius r of the S-shaped bend 248 depends on the
offset Y desired. As would be recognized by one skilled in the art,
the greater the degree of radius r, the greater the degree of
offset Y.
[0098] As would be recognized by one skilled in the art, both the
spindles 172 and 238 are designed to be used with a swing-arm type
suspension system such as that shown in FIGS. 9-12. Alternatively,
the spindles 172, 238 could not be used in combination with the
suspension illustrated in FIG. 19.
[0099] FIGS. 14 and 15 illustrate a ski leg 274 constructed
according to the present invention. The ski leg 274 is designed
specifically to be used in connection with a double A-arm
suspension as illustrated in FIG. 19. The ski leg 274 is
constructed to include an offset Y just as in the previous
embodiments. The term "ski leg" has been adopted for identification
of this particular component of the present invention. As would be
understood by those skilled in the art, however, the "ski leg" is
simply a modified spindle, as discussed above. Therefore, the terms
"spindle" and "ski leg" may be considered as synonymous in the
discussion that follows.
[0100] The ski leg 274 preferably is made of aluminum. In
particular, the ski leg 274 preferably is made as a unitary,
one-piece, aluminum extrusion. Aluminum is preferred because it may
be extruded easily. Also, aluminum is light in weight by comparison
with other materials and, therefore, does not add significantly to
the overall weight of the snowmobile to which it is attached. Of
course, other materials may be substituted therefor without
deviating from the scope of the present invention. For example, the
ski leg 274 may be made from steel or, perhaps, a composite
material.
[0101] A schematic illustration of the type of snowmobile on which
the ski leg 274 is incorporated is provided in FIG. 20. The
snowmobile 276 includes a frame 278 on which a seat 280 is
disposed. The frame 276 is powered by an engine (not shown) that is
disposed beneath the fairings 282 at the front of the vehicle. An
endless track 284 is disposed beneath the frame 278 and is
operatively connected to the engine to propel the snowmobile 276.
Two skis 286 are disposed at the front of the snowmobile 276. The
two skis are operatively connected to the handlebars 288 so that
the snowmobile 276 may be steered. The ski legs 274 are connected
to a front suspension system 290 that includes upper and lower
A-arms 292, 294. The upper and lower A-arms 292, 294 are connected
to the frame 278 of the snowmobile 276.
[0102] As illustrated in FIG. 20, the ski legs 274 extend
downwardly to the skis 286 from the front suspension 290.
[0103] The ski legs 274 include an elongated body portion 296 with
upper and lower forwardly-extending protrusions 298, 300. The
elongated body 296 also includes a rearwardly-extending protrusion
302. The ski leg 274 also includes a hole 304 near the bottom
portion 306 thereof. The hole 304 extends through the bottom
portion 306 to permit the ski leg 274 to pivot with respect to the
ski 286 attached thereto.
[0104] As illustrated in FIGS. 15 and 19, the forwardly-extending
protrusions 298, 300 are adapted to be connected to the upper and
lower A-arms 292, 294, respectively. The rearwardly-extending
portion 302 is adapted to be connected to a steering arm 293 so
that the ski leg 274 may be rotated to steer the snowmobile 276.
Preferably, the connection between the A-arms 292, 294 and the
forwardly-extending protrusions 298, 300 and the connection between
the steering arm and the rearwardly-extending portion 302 are via
ball joints 308, 310, 312. Ball joint connections permit the ski
leg 274 to rotate about an axis of rotation 314.
[0105] The axis of rotation 314 of the ski leg 274 is offset from
the transverse centerline 316 of the ski 286 by a preset distance
Y. As discussed above, the preset distance Y preferably is within
the range of about 0 to 25 mm, more preferably within the range of
about 5 to 20 mm, and most preferably about 16 mm. As indicated
above, the transverse centerline 316 marks approximately the center
point of the ski 286 if the ski 286 is symmetrical. Alternatively,
the transverse centerline 316 is defined as the approximate center
point between first and second sides 318, 320 of the lower portion
306 of the ski leg 274. In other words, the distances 322, 324 are
approximately equal to one another.
[0106] As shown in FIGS. 14 and 15, the axis of rotation 314 of the
ski leg 274 passes through the centers of the upper and lower ball
joints 308, 310. Since the side 320 preferably is the interior side
of the ski leg 274, the transverse centerline 316 is offset by the
distance Y toward the body of the snowmobile 276. FIG. 14,
therefore, illustrates the left ski 286 for the snowmobile 276.
This is the narrower stance for the skis 286.
[0107] To produce a wide stance with the ski leg 274, there are
several steps that must be followed. First, the ski leg must be
detached from the front suspension 290 of the snowmobile 276. This
is accomplished by decoupling the ski leg 274 from the three ball
joints 308, 310, 312. Next, the right and left ski legs 274 are
swapped for one another and reinstalled on the snowmobile 276. If
the skis 286 are not symmetrical, an additional step is required
that the skis 286 must be swapped for one another to maintain the
proper orientation on the front suspension 290.
[0108] The offset for the ski leg 274 is accomplished by providing
the lower portion 306 of the ski leg 274 with a protuberance 326.
In the embodiment illustrated in FIG. 14, the protuberance 326
extends toward the inside portion of the ski leg 274, thereby
decreasing the ski stance of the snowmobile 276. In this
embodiment, the protuberance 326 is integrally formed as a part of
the ski leg 274. As would be appreciated by those skilled in the
art, however, the protuberance 326 need not be formed as a part of
the lower portion 306 of the ski leg 274.
[0109] The ski leg 274 includes a plurality of holes 328 disposed
therethrough. The holes 328 lighten the weight of the ski leg 274.
Furthermore, the holes 328 are shaped so that they do not reduce
the overall strength and rigidity of the ski leg 274.
[0110] FIGS. 16-18 depict one possible alternative to the ski leg
274 illustrated in FIGS. 14 and 15. Here, the ski leg 330
incorporates a spacer 332 to effectuate the offset so that the ski
stance of the snowmobile (such as snowmobile 276) may be
altered.
[0111] FIGS. 16 and 17 provide a front elevational view of the ski
leg 330. As shown, the ski leg 330 includes indented portions 334
on either side thereof. The indented portions 334 are shaped to
accommodate a spacer 332 but are not required to practice the
present invention.
[0112] As with the previous embodiment of the ski leg 274, the ski
leg 330 includes a body 336 with upper and lower protrusions 338,
340. The upper and lower protrusions 338, 340 connect to the upper
and lower A-arms 292, 294 on the snowmobile 276. The ski leg 330
also includes a rearward projection (not illustrated) that connects
to the steering arm. A hole 342 extends through the lower portion
344 of the ski leg 330.
[0113] The ski leg 330 has an axis of rotation 346 that passes
through the ball joints (not shown) that are connected to the
protrusions 338, 340, just as with ski leg 274. When a spacer 332
is attached to the bottom portion 344 of the ski leg 330, a
transverse centerline 348 is established that is offset from the
axis of rotation 346 by a distance Y. As in the previous examples,
the distance Y preferably is within the range of about 0 to 25 mm,
more preferably within the range of about 5 to 20 mm, and most
preferably about 16 mm.
[0114] The spacer 332, a detailed view of which is provided in FIG.
18, includes a central hole 350 and two further holes 352, 354
disposed radially from the central hole 350. The spacer 332 also
has a width w, which corresponds to the appropriate width to be
added to the ski leg 330. As illustrated in FIGS. 16 and 17, the
spacer 332 may be attached to either side of the ski leg 330 with
two bolts 356, 358, which extend through the holes 352, 354.
[0115] Preferably, the spacer 332 is made from a material that is
light in weight such as aluminum. However, since the spacer bears
very little of the structural weight of the snowmobile, 276, it may
alternatively be made of a material such as plastic or steel.
[0116] Changing the ski stance of a snowmobile fitted with ski legs
330 is simpler than the same operation for a snowmobile fitted with
ski legs 274. With ski legs 330, the skis 286 must be removed.
Next, the spacer must be moved from the interior surface of the ski
leg 330 (FIG. 16) to the exterior surface (FIG. 17). The ski 286
may then be replaced onto the ski leg 330 in the same
orientation.
[0117] While the invention has been described with reference to
several 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. In addition, many
modifications may be made to adapt a particular situation,
component, or material to the teachings of the present invention
without departing from its teachings as claimed.
* * * * *