U.S. patent application number 09/841828 was filed with the patent office on 2002-04-18 for rear wheel support for atv.
Invention is credited to Suzuki, Takehito.
Application Number | 20020043422 09/841828 |
Document ID | / |
Family ID | 18637960 |
Filed Date | 2002-04-18 |
United States Patent
Application |
20020043422 |
Kind Code |
A1 |
Suzuki, Takehito |
April 18, 2002 |
Rear wheel support for ATV
Abstract
A recreational all terrain vehicle has a set of rear wheels
attached to a frame assembly with a swing arm. The rear wheels are
driven by a flexible transmitter, such as a chain. To tension the
chain, a pair of laterally extending bolts are loosened while a
generally longitudinally extending member is adjusted to move an
axle associated with the rear wheels. The housing portion of the
swing arm that receives the axle is substantially enclosed.
Inventors: |
Suzuki, Takehito; (Shizuoka,
JP) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
620 NEWPORT CENTER DRIVE
SIXTEENTH FLOOR
NEWPORT BEACH
CA
92660
US
|
Family ID: |
18637960 |
Appl. No.: |
09/841828 |
Filed: |
April 25, 2001 |
Current U.S.
Class: |
180/357 |
Current CPC
Class: |
B62K 2005/001 20130101;
B60Y 2200/20 20130101; B62K 5/027 20130101; B62K 5/01 20130101 |
Class at
Publication: |
180/357 |
International
Class: |
B60K 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2000 |
JP |
2000-128532 |
Claims
What is claimed is:
1. A recreational all terrain vehicle comprising a frame assembly,
an engine disposed within said frame assembly, said engine adapted
to power an output shaft, a drive pulley secured to said output
shaft, a swing arm pivotally connected to said frame assembly, a
pair of rear wheels supported by said swing arm, a pivot axis being
defined at a location in which said swing arm is pivotally
connected to said frame assembly, said swing arm comprising a
forward neck portion and a rearward bearing carrying portion, an
axle being connected to said pair of rear wheels, said axle adapted
to rotate about an axle rotational axis, said pivot axis and said
axle rotational axis being generally parallel, a driven pulley
being connected to said axle, a flexible transmitter extending
around said drive pulley and said driven pulley, said bearing
carrying portion comprising an outer housing secured to said neck
portion, said axle extending through a transverse opening extending
through a portion of said outer housing, a pair of plates
positioned on lateral sides of said outer housing and at least
partially closing said transverse opening, a tubular member
extending through said transverse opening and being connected to
said pair of plates, a first fastener and a second fastener
transversely extending between said pair of plates and said first
fastener and said second fastener being adapted to secure said pair
of plates to said outer housing.
2. The vehicle of claim 1, wherein said plates are adapted for
longitudinal movement relative to said outer housing when said
first and second fasteners are loosened.
3. The vehicle of claim 2, wherein at least one elongated member
extends through a portion of said outer housing and contacts at
least one of said first fastener and said second fastener.
4. The vehicle of claim 3, wherein said at least one elongated
member comprises an externally treaded portion.
5. The vehicle of claim 3, wherein said plates are moved by
inserting and retracting said at least one elongated member into
and out of said outer housing.
6. The vehicle of claim 1, wherein said first fastener is
positioned above said second fastener and said first fastener is
positioned forward of said second fastener.
7. The vehicle of claim 6, wherein said axle rotational axis is
disposed between said first fastener and said second fastener.
8. The vehicle of claim 6, wherein a threaded member is threadedly
engaged with said outer housing, is rotatable about an axis that
extends through said first fastener and is capable of contacting
said first fastener.
9. The vehicle of claim 8, wherein said axis of said threaded
member extends through a rotational axis of said first
fastener.
10. The vehicle of claim 8, wherein said first fastener extends
within a transversely disposed slot having a major axis, said axis
of said first fastener being generally aligned with said major
axis.
11. The vehicle of claim 1, wherein said outer housing comprises an
upper lug, said upper lug extending above a portion of said neck
portion of said swing arm and said upper lug being secured to said
portion of said neck portion.
12. The vehicle of claim 11, wherein a threaded member extends
through at least a portion of said upper lug and contacts said
first fastener.
13. The vehicle of claim 1 further comprising a brake caliper, said
brake caliper being supported by said swing arm.
14. The vehicle of claim 13, wherein said brake caliper is
supported by said outer housing.
15. The vehicle of claim 14, wherein said brake caliper is
supported by an upper rear portion of said outer housing.
16. A swing arm for a recreational all terrain vehicle comprising a
neck portion and a bearing carrier portion, said neck portion
extending partway into said bearing carrier portion and being
secured to said bearing carrier portion, said bearing carrier
portion comprising an outer housing, said outer housing defining a
transverse opening, a first slot and a second slot also extending
transversely through said outer housing and being generally
parallel to said transverse opening, a first plate being attached
to a first lateral side of said outer housing and a second plate
being attached to a second lateral side of said outer housing, a
first elongated member extending through said first slot and a
second elongated member extending through said second slot, said
first plate and said second plate substantially covering said
transverse opening and being secured to said outer housing by said
first elongated member and said second elongated member.
17. The swing arm of claim 16, wherein said first elongated member
and said second elongated member comprise bolts.
18. The swing arm of claim 16, wherein said outer housing further
comprises an upper lug disposed in a forward location of said
bearing carrier portion and above at least a portion of said neck
portion, a threaded member extending through said upper lug and
contacting said first elongated member.
19. The swing arm of claim 18, wherein said threaded member
comprises an axis of rotation, said first slot comprises a first
major axis and said axis of rotation extends along said first major
axis.
20. The swing arm of claim 19, wherein said second slot comprises a
second major axis, said second major axis being generally parallel
to said first major axis.
21. The swing arm of claim 16, wherein said first elongated member
is disposed generally forward of and above said second elongated
member.
22. The swing arm of claim 21 further comprising a mounting
arrangement adapted to receive a brake caliper.
23. The swing arm of claim 22, wherein said mounting arrangement is
disposed rearward of said first elongated member.
24. The swing arm of claim 16 in combination with a recreational
all terrain vehicle, said all terrain vehicle comprising a frame
assembly, an engine disposed within said frame assembly, said
engine adapted to power an output shaft, a drive pulley secured to
said output shaft, said swing arm pivotally connected to said frame
assembly, a pair of rear wheels supported by said swing arm, a
pivot axis being defined at a location in which said swing arm is
pivotally connected to said frame assembly, an axle being connected
to said pair of rear wheels, said axle adapted to rotate about an
axle rotational axis, said pivot axis and said axle rotational axis
being generally parallel, a driven pulley being connected to said
axle, a flexible transmitter extending around said drive pulley and
said driven pulley.
25. A recreational all terrain vehicle comprising a frame assembly,
an engine disposed within said frame assembly, said engine adapted
to power an output shaft, a drive pulley secured to said output
shaft, a swing arm pivotally connected to said frame assembly, a
pair of rear wheels supported by said swing arm, a pivot axis being
defined at a location in which said swing arm is pivotally
connected to said frame assembly, said swing arm comprising a
forward neck portion and a rearward bearing carrying portion, an
axle being connected to said pair of rear wheels, said axle adapted
to rotate about an axle rotational axis, said pivot axis and said
axle rotational axis being generally parallel, a driven pulley
being connected to said axle, a flexible transmitter extending
around said drive pulley and said driven pulley, said neck portion
extending partway into said bearing carrying portion and being
secured to said bearing carrier portion, said bearing carrying
portion comprising an outer housing that defines a transverse
opening, a first slot and a second slot also extending transversely
through said outer housing and being generally parallel to said
transverse opening, said axle extending through said transverse
opening, a pair of plates positioned on opposing lateral sides of
said outer housing, a first elongated member and a second elongated
member extending through said first slot and said second slot
respectively and said pair of plates substantially covering said
transverse opening and being secured to said outer housing by said
first elongated member and said second elongated member.
Description
RELATED APPLICATIONS
[0001] This application is related to and claims the priority of
Japanese Patent Application No. 2000-127,183, which was filed on
Apr. 27, 2000, the entire contents of which is hereby expressly
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates mounting
arrangements for rear axles of land vehicles. More particularly,
the present invention relates to such mounting arrangements in
three or four wheel vehicles, such as all terrain vehicles
(ATVs).
[0004] 2. Description of the Related Art
[0005] Recreational all terrain vehicles generally comprise a frame
that is carried by at least one front wheel and a pair of rear
wheels. The rear wheels typically are attached to the frame with a
swing arm, which is connected to a rear portion of the frame and
which is capable of pivotal movement relative to the frame about a
generally horizontal axis. A shock absorber often is disposed
between the swing arm and the frame to control movement of the
swing arm during operation of the vehicle over rough terrain.
[0006] One example of such a swing arm was disclosed in Japanese
Patent No. 2535328. FIG. 1 reproduces FIG. 1 of that patent. As
illustrated, the swing ann 10 generally comprises an elongated neck
portion 12 and a bearing carrying portion 14. A forward end of the
elongate neck portion 12 comprises a pivot shaft 16 and a bearing
configuration 18 to promote pivotal movement of the swing arm 10
relative to the frame to which the swing arm 10 is attached. A
flange 20 is provided along the neck portion 12. The flange 20
provides a connecting location for a shock absorber or damper.
[0007] The bearing carrying portion 14 is connected to the rear end
of the neck portion 12. In the illustrated arrangement, the bearing
carrying portion 14 is comprised of a square tube 22. The square
tube 22 generally is welded directly to the neck portion 12 and
provides a housing in which an axle 24 of the vehicle is
mounted.
[0008] Two sets of bearings 26 positioned within a housing having
an upper block 28 and a lower block 30 are disposed within the tube
22. A set of four threaded fasteners 32, two of which are shown,
are used to secure the housing in position within the tube 22. The
threaded fasteners extend through longitudinal slots 34 formed in
the top and bottom surfaces of the square tube 22. Thus, the
longitudinal position of the axle 24 can be adjusted forward and
backward.
[0009] A further threaded fastener 36 extends rearward from the
rear of the housing and through the square tube. This threaded
fastener 36 receives nuts 38 that can be tightened to pull the axle
24 rearward through the bearing carrying portion 14 such that
tension is increased to a chain used to drive the rear axle 24.
[0010] One drawback to this swing arm construction is that the
lateral ends of the square tube are not enclosed. Thus, dust, dirt
and other debris can easily become lodged in the tube. Not only
does this detract from an otherwise clean vehicle, but the dirt can
hamper maintenance and increase wear. For instance, if the chain
needs to be slacked, then the dirt must be cleared sufficiently
from within the tube to allow the bearings and the associated
housing to be moved forward within the tube.
[0011] Another drawback to this swing arm construction relates to
providing tension to the chain. As can be appreciated, the size of
the threaded fastener 36 must be fairly substantial to withstand
the loads applied when tensioning the chain. At least two
conditions necessitate the increased size. First, only a single
member is used to apply the initial tension. Second, the single
member is receiving a tensile load under most conditions even
though the other threaded fasteners are tightened into
position.
SUMMARY OF THE INVENTION
[0012] Accordingly, an improved swing arm construction is desired
whereby the above-noted drawbacks can be overcome. In addition, the
improved construction preferably provides simpler manufacture as
well as maintenance.
[0013] Accordingly, one aspect of the present invention involves a
recreational all terrain vehicle comprising a frame assembly with
an engine disposed within the frame assembly. The engine is adapted
to power an output shaft and a drive pulley is secured to the
output shaft. A swing arm is pivotally connected to the frame
assembly with a pair of rear wheels being supported by the swing
arm. A pivot axis is defined at a location in which the swing arm
is pivotally connected to the frame assembly. The swing arm
comprises a forward neck portion and a rearward bearing carrying
portion. An axle is connected to the pair of rear wheels with the
axle being adapted to rotate about an axle rotational axis. The
pivot axis and the axle rotational axis are generally parallel. A
driven pulley is connected to the axle with a flexible transmitter
extending around the drive pulley and the driven pulley. The
bearing carrying portion comprises an outer housing secured to the
neck portion. The axle extends through a transverse opening
extending through a portion of the outer housing. A pair of plates
are positioned on lateral sides of the outer housing and at least
partially close the transverse opening. A tubular member extends
through the transverse opening and is connected to the pair of
plates. A first fastener and a second fastener transversely extend
between the pair of plates while the first fastener and the second
fastener are adapted to secure the pair of plates to the outer
housing.
[0014] Another aspect of the present invention involves a swing arm
for a recreational all terrain vehicle. The swing arm comprises a
neck portion and a bearing carrier portion. The neck portion
extends partway into the bearing carrier portion and is secured to
the bearing carrier portion. The bearing carrier portion comprises
an outer housing with the outer housing defining a transverse
opening. A first slot and a second slot also extend transversely
through the outer housing and are generally parallel to the
transverse opening. A first plate is attached to a first lateral
side of the outer housing and a second plate is attached to a
second lateral side of the outer housing. A first elongated member
extends through the first slot and a second elongated member
extends through the second slot. The first plate and the second
plate substantially cover the transverse opening and are secured to
the outer housing by the first elongated member and the second
elongated member.
[0015] A further aspect of the present invention involves a
recreational all terrain vehicle comprising a frame assembly with
an engine disposed within the frame assembly. The engine is adapted
to power an output shaft with a drive pulley being secured to the
output shaft. A swing arm is pivotally connected to the frame
assembly. A pair of rear wheels are supported by the swing arm and
a pivot axis is defined at a location in which the swing arm is
pivotally connected to the frame assembly. The swing arm comprises
a forward neck portion and a rearward bearing carrying portion. An
axle is connected to the pair of rear wheels with the axle being
adapted to rotate about an axle rotational axis. The pivot axis and
the axle rotational axis are generally parallel. A driven pulley is
connected to the axle with a flexible transmitter extending around
the drive pulley and the driven pulley. The neck portion extends
partway into the bearing carrying portion and is secured to the
bearing carrier portion. The bearing carrying portion comprises an
outer housing that defines a transverse opening. A first slot and a
second slot also extend transversely through the outer housing and
are generally parallel to the transverse opening. The axle extends
through the transverse opening. A pair of plates are positioned on
opposing lateral sides of the outer housing. A first elongated
member and a second elongated member extend through the first slot
and the second slot respectively and the pair of plates
substantially cover the transverse opening. The pair of plates are
secured to the outer housing by the first elongated member and the
second elongated member.
[0016] For purposes of summarizing the invention and the advantages
achieved over the prior art, certain objects and advantages of the
invention have been described herein above. Of course, it is to be
understood that not necessarily all such objects or advantages may
be achieved in accordance with any particular embodiment of the
invention. Thus, for example, those skilled in the art will
recognize that the invention may be embodied or carried out in a
manner that achieves or optimizes one advantage or group of
advantages as taught herein without necessarily achieving other
objects or advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] These and other features, aspects and advantages of the
present invention will be described with reference to accompanying
drawings. The drawings comprise six figures.
[0018] FIG. 1 is a side elevation view of a prior swing arm
construction with the axle being shown in section.
[0019] FIG. 2 is a simplified side elevation view of an all terrain
vehicle having a swing arm arranged and configured in accordance
with the present invention. Certain features of the vehicle are
outlined in phantom and an arrow labeled "F" is provided to show
the forward direction.
[0020] FIG. 3 is a simplified top plan view of the vehicle of FIG.
2. Certain features of the vehicle are outlined in phantom and an
arrow labeled "F" is provided to show the forward direction.
[0021] FIG. 4 is an enlarged partially sectioned side elevation
view of a rear portion of a swing arm used in the vehicle of FIG.
2.
[0022] FIG. 5 is an enlarged top plan view of the portion of the
swing arm shown in FIG. 4 taken along the line 5-5 in FIG. 4.
[0023] FIG. 6 is a sectioned view of the portion of the swing arm
shown in FIG. 4 taken along the line 6-6 in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] With reference initially to FIGS. 1 and 2, an all terrain
vehicle having a swing arm arranged and configured in accordance
with certain features, aspects and advantages of the present
invention is illustrated therein. While the swing arm will be
described in the context of a four wheeled all terrain vehicle,
other vehicles also can employ certain features, aspects and
advantages of the present invention. For instance, vehicles having
a belt driven or chain driven rear wheel can benefit from certain
features of the present invention. Thus, vehicles such as motor
scooters, lawn mowers, go carts and the like can benefit from some
of the features of the present invention. In addition, vehicles
employing swing arms similar to that disclosed can benefit from
certain features of the present invention.
[0025] With continued reference to FIGS. 1 and 2, the illustrated
vehicle 40 generally comprises a pair of front wheels 42 and a pair
of rear wheels 44. The dirigible front wheels 42 carry a forward
portion of a frame assembly 46. The rear wheels 44 are connected to
the frame assembly 46 by a suspension system 47 that includes the
swing arm 48. With the assistance of a shock absorber 50 and an
attached two bar linkage 51, the swing arm 48 supports a rear
portion of the illustrated frame assembly 46. The swing arm 48 is
connected to the frame assembly 46 at a pivot axis P by a pivot
shaft 52. In the illustrated arrangement, the pivot axis P is
forward of a rear elbow of the frame assembly (i.e., disposed
within the frame assembly); however, in other arrangements, the
pivot axis P may be positioned rearward of the frame assembly
(i.e., disposed outside of the frame assembly).
[0026] The frame assembly 46 supports a number of body components
of the vehicle 40. For instance, a forward fender assembly 54 can
be positioned over the dirigible front wheels 42. The fender
assembly 54 preferably includes a forward cowling that wraps
rearward around a portion of a steering handle arrangement 56. The
steering handle arrangement 56 is operably connected to the front
wheels 42 to steer the front wheels in a known manner.
[0027] Rearward of the illustrated steering handle arrangement, a
fuel tank 58 and a seat 60 are supported by the frame assembly 46
in any suitable manner. The frame assembly 46 also defines an
engine compartment 62 within which an engine 64 is mounted in a
suitable manner. An output shaft 66 that is driven by the engine 64
is disposed generally forward of the pivot axis P in the
illustrated arrangement. Preferably, the output shaft 66 is
disposed within a transfer case 68 and is driven by a transmission
that is also contained at least in part within the transfer case
68.
[0028] The rear wheels 44 preferably are driven by the rotational
power output from the output shaft 66. In the illustrated
arrangement, the output shaft 66 drives the rear wheels 44 through
a chain drive 70; however, belt drives and other suitable driving
configurations also can be used. As illustrated, the output shaft
66 carries a drive sprocket 72. The drive sprocket 72 powers a
driven sprocket 74 that is connected to an axle 76 of the rear
wheels 44. The driven sprocket 74 and the rear axle 76 preferably
rotate about a rear axis of rotation R.
[0029] It should be mentioned that, in the case of independently
suspended rear wheels, the driven sprocket 74 can be connected to
the associated constant velocity joints in any suitable manner.
Preferably, a chain guide 78 and a tensioning roller 80 also are
provided. The chain guide reduces wear on the chain and maintains
accurate loading of the chain onto the drive sprocket 72 while the
tensioning roller 80 helps remove slack created during movement of
the swing arm 48 relative to the frame assembly 46. Moreover, while
implicit in the above-discussion, the chain drive 70 also includes
a roller chain 82, or any other suitable, flexible and endless
transmitter.
[0030] As discussed above, the swing arm 48 preferably comprises a
neck portion 84 and a bearing carrying portion 86. The neck portion
84 extends rearward to the bearing carrying portion 86. Thus, the
neck portion 84 is pivotally attached to the frame assembly 46 and
the bearing carrying portion 86 supports the axle 76 for rotation.
Of course, the bearing carrying portion 86 allows adjustment of the
axle location relative to the frame assembly 46 such that the
distance between the pivot axis P and the rotational axis R can be
adjusted to increase or decrease the tension on the stationary
chain drive 70.
[0031] With reference now to FIGS. 4 and 5, the illustrated linkage
51 is connected to the swing arm at a pair of pivot locations. In
the illustrated configuration, the linkage 51 extends through an
opening formed in the neck portion 84 of the swing arm 48 just
forward of the bearing carrying portion 86. The linkage 51 is
connected to the swing arm 48 at a pair of mounted bosses 90. The
mounting bosses 90 contain suitable bearing or bushing arrangements
92 and are reinforced rearward of the pivot axis defined through
the bearing or bushing arrangements 92. The reinforcement helps
solidify the mounting bosses 90 and helps to reduce the likelihood
of fractures along this load bearing portion of the swing arm 48.
Furthermore, in the illustrated arrangement, the mounting bosses 90
extend outward from a sleeve 94, which encases a substantial
portion of the rear end of the swing arm 48. The sleeve 94 further
stiffens the load bearing portion of the swing arm 48 and provides
a reinforcing location to which the bearing carrying portion 86 can
be mounted, in a manner that will now be described.
[0032] With reference now to FIGS. 4-6, a presently preferred
construction of the bearing carrying portion 86 will be described
in greater detail. In the illustrated arrangement, the bearing
carrying portion 86 comprises an outer housing 100. The outer
housing 100 preferably is cylindrical in configuration as this
configuration helps to reduce stress-risers within the
construction. Of course, depending upon the material selection and
the chosen configuration, other outer housing shapes can be
used.
[0033] In addition, the connection between the outer housing 100
and a rear portion 101 of the swing arm 48 is advantageously
reinforced due to the technique in which the two components are
attached. In particular, with reference to FIG. 4, the sleeve 94
has a rear face that is terminated short of the rear end of the
swing arm 48. Thus, in the illustrated arrangement, the swing arm
48 extends through the sleeve 94. The swing arm and the sleeve are
contoured to receive the outer housing 100. In addition, the outer
housing further comprises an upper lug 102. In particular, in the
illustrated arrangement, the upper lug 102 has a lower surface that
interfaces with the swing arm 48 while the forward end of the upper
lug 102 contacts the end of the sleeve 94. In some configurations,
such as in the illustrated arrangement, a gap G is positioned
between a portion of the upper lug 102 and the swing arm 48. Thus,
the rear portion 101 of the swing arm 48 can have an increased weld
line to increase the strength of the connection between the neck
portion 84 and the bearing carrying portion 86.
[0034] With continued reference to FIG. 4, the outer housing 100
also comprises a lower lug 104. The lower lug 104 extends downward
and rearward while the upper lug 102 extends upward and forward
from a main portion of the outer housing 100. Formed within the
illustrated upper lug 102 is a first longitudinal slot 106 and
formed within the illustrated lower lug 104 is a second
longitudinal slot 108. While the illustrated slots 106, 108 are
aligned with each other and extend along generally parallel major
axes, the slots could be slightly skewed relative to each other.
Advantageously, when arranged in parallel, the slots 106, 108 allow
easy adjustment of the axle 76 in a longitudinal direction.
[0035] With reference now to FIG. 5, the slots 106, 108 extend
through the lugs 102, 104 of the outer housing 100. The slots 106,
108 align with openings 110, 112 formed in a pair of outer plates
114, 116 respectively. The outer plates 114, 116 comprise a left
plate 114 and a right plate 116 in the illustrated arrangement. As
will be appreciated, the nomenclature of left and right is for easy
of reference as the plates can be interchanged in varied
applications. Preferably, the openings 110, 112 are circular,
however. By forming the openings 110, 112 in a circular
configuration rather than slots, the increased surface friction
between the plates 114, 116 and the outer housing 100 can be used,
at least in part, to secure the plates in position. The friction,
of course, is increased due to the increased contact area.
[0036] The friction is caused when a first bolt 118 and a second
bolt 120 are drawn tight with the plates and the outer housing
positioned between opposing faces of each bolt 118, 120. While
bolts are used in the illustrated arrangement, other threaded
fasteners also can be used. Moreover, other mechanical components
that place intervening members in compression while being placing
at least a portion of the mechanical component in tension also can
be used.
[0037] In the illustrated arrangement, the bolts 118, 120 each
comprises an elongated head portion 122, 124. Each head portion
122, 124 is received within a respective slotted opening 126, 128
formed within the plates 114, 116. As illustrated, this recess
preferably does not extend completely through the plate such that
the plates can be secured by the bolts 118, 120. In addition, a
washer and nut assembly 130, 132 preferably is disposed on the
opposing end of the bolts 118, 120 respectively. Furthermore, a
shank 134, 136 of each bolt 118, 120 preferably extends through the
respective slot 106, 108 and each shank 134, 136 is rotatable about
a separate bolt axis B1, B2.
[0038] With particular reference now to FIG. 6, the two plates 114,
116 will be described in more detail. As illustrated, the left
plate 114 comprises a generally tubular extension 140. The
extension 140 preferably is sized and configured to extend through
an opening 142 defined within the outer housing 100 between the
slots 106, 108. The illustrated extension 140 extends through the
outer housing 100 and through the right plate 116 for reasons that
will become apparent. In addition, the illustrated extension has a
necked-down portion 144 proximate a center of the outer housing
100. The necked-down portion 144 places an inner wall of the
extension 140 in closer proximity to the outside surface of the
axle 76 in this location.
[0039] Additionally, the extension 140 comprises a proximal end 146
and a distal end 148. The proximal end 146 has an outer portion,
which is adjoined with the plate surface 114 in the illustrated
arrangement, that is counterbored to receive a bearing 150 and a
seal 152. The distal end of the sleeve also is counterbored to
receive a bearing 154 and a seal 156. The bearings 150, 154 journal
the axle 76 and the seals reduce or eliminate dirt infiltration
into the extension 140. In some arrangements, a bushing or sleeve
can encase the axle 76 to reduce wear between the inner wall of the
extension 140 and the axle 76.
[0040] The illustrated arrangement, thus, defines an enclosed
chamber 158 that is substantially sealed from the elements, such as
dirt, dust and the like. Furthermore, this chamber 158 accommodates
relative movement of the axle 76 during adjustment of chain
tension. During adjustment, the plates 114, 116 move relative to
the housing 100; however, the movement of the plates 114, 116
preferably does not result in large openings into the inner chamber
158. Therefore, the inner chamber 158 does not collect mud, dirt
and dust and the appearance of the vehicle, when hosed off after
riding, is improved. Furthermore, the inner chamber remains
substantially free of movement-blocking materials such that
adjustment can be readily made in a manner which will not be
described.
[0041] With reference again to FIGS. 4 and 5, a pair of apertures
160 are formed in the upper lug 102. The apertures 160 preferably
define central axes A that extend generally through the bolt 118.
More preferably, the axes A extend through the shank 134 of the
bolt 118. Most preferably, the apertures 160 define central axes A
that extend generally normal to the bolt 118 and that extend
through the centerline of the bolt B1. In addition, the axes A
preferably are parallel to the major axis of the slot 106 and more
preferably are aligned with a plane extending through the slot 106
along the major axis of the slot 106.
[0042] A threaded member, such as a bolt 162, is threadedly engaged
within each aperture 162. In some configurations, a threaded
insert, a weld-nut or the like can be disposed in an appropriate
location relative to each of the apertures 160. The bolt 162,
therefore, can be turned into and out of the upper lug 102. By
turning the bolts 162 into the lug 102, the bolts 162 act against
the bolt 118. Thus, the bolt can push the bolt 118 outward to
tension the chain. While the illustrated arrangement features two
bolts 162 that are symmetrically arranged, a single bolt and more
than two bolts can be used. Additionally, while symmetry is
desired, an asymmetric pattern also can be used depending upon the
application. In addition, each bolt 162 receives a lock nut 164.
The lock nut 164 can be used to fix the position of the bolt 162
relative to the lug 102 when the appropriate chain tension has been
achieved. The lock nut 164 advantageously reduces the likelihood
that the bolt 162 will loosen over time due to vibrations
resonating in the frame assembly 64.
[0043] With reference still to FIGS. 4 and 5, the right plate 116
also comprises a pair of outwardly extending ears 170 that serve as
mounts for a portion of a brake assembly 172. Each of the ears 170
contains a mounting boss 174 that receives a fastener 176. The
fasteners 176 secure a brake caliper 178 in position relative to
the swing arm 48. As is known, the brake caliper squeezes a brake
disc 180 that is fastened to the axle 76 in any suitable manner.
The squeezing of the brake 180, which is typically rotating
counterclockwise in FIG. 4 during forward movement of the vehicle,
slows the rotation of the axle 76 and brings the vehicle to a
stop.
[0044] As can be appreciated, the positioning of the caliper places
a large moment on the bearing carrying portion 86 and particularly
on the joint between the bearing carrying portion 86 and the neck
portion 84. Additionally, the moment acts against the bolt 162.
Advantageously positioned, the bolt 162 receives compressive
loading rather than tensile loading (which is received by the
threaded member in the prior arrangement illustrated in FIG.
1).
[0045] Additionally, with reference to FIG. 4, a plane passing
through the centers of the bolts 118, 120 extends at an angle to a
vertical plane V extending through the axle 76. Preferably, the
upper portion of the plane, which coincides with the plane 6-6,
that is above the axle 76 is forward of the axle. More preferably,
this plane intersects the rotational axis R of the rear axle 76. In
this manner, the loading created during breaking, which includes a
moment created in the upper rear portion of the brake disc 180, is
effectively countered.
[0046] Furthermore, the slots are preferably positioned such that
the bolts 118, 120 are generally positioned on opposing sides of
the vertical axis. While in the illustrated arrangement, some
portion of the upper bolt 118 may extend rearward of the vertical
plane V, the upper bolt 118 preferably is always forward of the
generally vertical plane V.
[0047] In use, the bolts 118, 120 can be loosened. With these bolts
118, 120 loosened, the bolts 162 can be used to urge the pivot axis
P away from the rear axle rotational axis R or can be retracted
such that the tension on the chain can be reduced. When the bolts
162 are retracted, the tension forces on the chain will draw the
axle forward. When the chain has been appropriately tensioned, such
as by adjusting the bolts 162, the transverse bolts 118, 120 can be
tightened. With the transverse bolts 118, 120 tightened, the chain
tension is then fixed. Adjustment can be made as desired or
necessary over time.
[0048] Although the present invention has been described in terms
of a certain embodiment, other embodiments apparent to those of
ordinary skill in the art also are within the scope of this
invention. Thus, various changes and modifications may be made
without departing from the spirit and scope of the invention. For
instance, various components may be repositioned as desired.
Moreover, not all of the features, aspects and advantages are
necessarily required to practice the present invention.
Accordingly, the scope of the present invention is intended to be
defined only by the claims that follow.
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