Note: Descriptions are shown in the official language in which they were submitted.
DRIVE CLUTCH FOR A CONTINUOUSLY VARIABLE TRANSMISSION
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This Application claims priority to U.S. Provisional Application
Serial No.
63/307,360, same title herewith, filed on February 7, 2022, which is
incorporated in its entirety
herein by reference.
BACKGROUND
[0002] A continuously variable transmission (CVT) includes a drive clutch
(primary clutch)
and a driven clutch (secondary clutch). The drive clutch is typically in
operational
communication with an engine to receive engine torque and the driven clutch is
in operational
communication with a driveline of an associated vehicle. The driven clutch is
in rotational
communication with the drive clutch via endless loop member such as a belt.
The drive clutch
includes a movable sheave assembly that is configured move axially on a post
as rotational speed
and centrifugal forces increase and decrease. The movable sheave assembly
axially moves on
the post either away from or towards a fixed sheave. The belt, riding on faces
of the fixed and
movable sheave assemblies move radially either towards a central axis of the
drive clutch or
away from the central axis therein changing the gear ratio of the CVT.
[0003] One common type of movable sheave assembly uses a dual ramp (sheave
and
spider)/centrifugal sliding element configuration to generate belt clamp
forces (i.e., move the
moveable sheave portion on the post towards the fixed sheave). The sliding
interface of the
centrifugal sliding element on the ramp surfaces creates friction. This
friction results in
undesired wear at the centrifugal sliding element therein limiting CVT
shifting performance.
[0004] For the reasons stated above and for other reasons stated below
which will become
apparent to those skilled in the art upon reading and understanding the
present specification,
there is a need in the art for an improved and effective drive clutch with
reduced wear.
1
Date Recue/Date Received 2023-02-06
SUMMARY OF INVENTION
[0005] The following summary is made by way of example and not by way of
limitation. It
is merely provided to aid the reader in understanding some of the aspects of
the subject matter
described. Embodiments provide an improved drive clutch with a novel rolling
centrifugal
element assembly.
[0006] In one embodiment, a drive clutch for a continuously variable
transmission is
provided. The drive clutch includes a post, a fixed sheave, a movable sheave
assembly, a
plurality of spaced sheave ramps, a spider, and a plurality of roller
centrifugal elements. The
fixed sheave is statically mounted on an end of the post. The movable sheave
assembly is
slidably mounted on the post. The movable sheave assembly includes a housing
that forms at
least in part an interior chamber. The plurality of spaced sheave ramps are
positioned within the
interior chamber of the housing of the movable sheave assembly. The spider is
received within
the housing of the movable sheave assembly. The spider is statically mounted
on the post. The
spider includes a plurality of spaced radially extending spider ramp arms.
Each spider ramp arm
includes at least one spider ramp. The plurality of roller centrifugal
elements are received within
the interior chamber of the housing of the movable sheave. Each roller
centrifugal element
includes at least one sheave ramp roller and at least one spider ramp roller.
The at least one
sheave ramp roller is configured to engage one of an associated sheave ramp
and associated
spider ramp and the at least one spider ramp roller configured to engage
another one of the
associated sheave ramp and associated spider ramp.
[0007] In another embodiment, a rolling centrifugal element for a clutch of
a continuously
variable transmission is provided. The rolling centrifugal element includes an
axle and at least
one sheave ramp roller and at least one spider ramp roller mounted on the
axle. The at least one
sheave ramp roller is configured to engage one of an associated sheave ramp of
a movable
sheave assembly of the clutch and an associated spider ramp of a spider and
the at least one
spider ramp roller configured to engage another one of the associated sheave
ramp and the
associated spider ramp. The at least one sheave ramp roller is configured to
rotate independent
of the at least one sheave ramp roller.
2
Date Recue/Date Received 2023-02-06
[0008] In yet another example, a vehicle is provided. The vehicle includes
an engine to
produce engine torque, a driveline and a CVT. The CVT includes a driven clutch
and a drive
clutch. The driven clutch is in operational communication with the driveline.
The drive clutch is
in operational communication with the engine. The drive clutch includes a
post, a fixed sheave,
a movable sheave assembly, a plurality of spaced sheave ramps, a spider, and a
plurality of roller
centrifugal elements. The fixed sheave is statically mounted on an end of the
post. The movable
sheave assembly is slidably mounted on the post. The movable sheave assembly
includes a
housing that forms at least in part an interior chamber. The plurality of
spaced sheave ramps are
positioned within the interior chamber of the housing of the movable sheave
assembly. The
spider is received within the housing of the movable sheave assembly. The
spider is statically
mounted on the post. The spider includes a plurality of spaced radially
extending spider ramp
arms. Each spider ramp arm includes at least one spider ramp. The plurality of
roller centrifugal
elements are received within the interior chamber of the housing of the
movable sheave. Each
roller centrifugal element includes at least one sheave ramp roller and at
least one spider ramp
roller. The at least one sheave ramp roller is configured to engage one of an
associated sheave
ramp and associated spider ramp and the at least one spider ramp roller
configured to engage
another one of the associated sheave ramp and associated spider ramp. An
endless looped
member couples torque between the drive clutch and the driven clutch.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention can be more easily understood and further
advantages and uses
thereof will be more readily apparent, when considered in view of the detailed
description and
the following figures in which:
[0010] Figure 1 is a side perspective view of an assembled drive clutch
according to one
exemplary aspect of the present invention;
[0011] Figure 2 is a cross-sectional side perspective view of the drive
clutch of Figure 1
illustrating portions of rolling centrifugal elements in a cavity of a housing
of a movable sheave
assembly according to one exemplary aspect of the present invention;
3
Date Recue/Date Received 2023-02-06
[0012] Figure 3 is an assembled side perspective view of a rolling
centrifugal element
according to one exemplary aspect of the present invention;
[0013] Figure 4 is a cross-sectional side perspective view of the rolling
centrifugal element
of Figure 3;
[0014] Figure 5 is an end perspective view of a spider and rolling
centrifugal elements
according to one exemplary aspect of the present invention;
[0015] Figure 6 a cross-sectional end perspective view of a housing of a
movable sheave
assembly and rolling centrifugal elements according to one exemplary aspect of
the present
invention;
[0016] Figure 7 is a close up view cross-sectional view of a roller
centrifugal element within
the housing of the movable sheave assembly according to one exemplary aspect
of the present
invention;
[0017] Figure 8 is a block diagram of a vehicle employing a drive clutch
according to one
exemplary aspect of the present invention; and
[0018] Figure 9 is a partial cross-sectional close-up view of a moveable
sheave member
according to one exemplary aspect of the present invention.
[0019] In accordance with common practice, the various described features
are not drawn to
scale but are drawn to emphasize specific features relevant to the present
invention. Reference
characters denote like elements throughout Figures and text.
DETAILED DESCRIPTION
[0020] In the following detailed description, reference is made to the
accompanying
drawings, which form a part hereof, and in which is shown by way of
illustration specific
embodiments in which the inventions may be practiced. These embodiments are
described in
sufficient detail to enable those skilled in the art to practice the
invention, and it is to be
understood that other embodiments may be utilized and that changes may be made
without
departing from the spirit and scope of the present invention. The following
detailed description
4
Date Recue/Date Received 2023-02-06
is, therefore, not to be taken in a limiting sense, and the scope of the
present invention is defined
only by the claims and equivalents thereof.
[0021] Embodiments of the present invention provide an improved clutch for
a CVT.
Embodiments employ rolling centrifugal elements that eliminate a sliding
interface between a
spider and sheave. In one example, rolling centrifugal elements split a
centrifugal element
contact between a pair of rollers that contact a spider ramp and a single
roller that contacts a
sheave ramp. Further in an example embodiment, all three rollers of a rolling
centrifugal
element are assembled and contained on a central axle with a pair of thrust
washers and clips as
discussed below in detail.
[0022] Referring to Figure 1, an assembled side perspective view of a
clutch, such as drive
clutch, of a CVT of an example embodiment is illustrated. The drive clutch
100, which may be
referred to as a drive sheave, includes a fixed sheave 102 and a movable
sheave assembly 104.
Figure 2 illustrates a cross-sectional side view of the drive clutch 100
illustrating a rolling
centrifugal element 150 positioned within a housing 106 of the movable sheave
assembly 104.
The fixed sheave 102 is statically mounted on an end of post 110. Portions of
the movable
sheave assembly 104 are slidably mounted on the post 110. A spider 130 within
the housing 106
of the movable sheave assembly 104, is axially fixed (statically fixed) on the
post 110. A cover
108, in this example, engages the housing 106 to form an interior chamber 107
of the movable
sheave assembly 104. In another example, the housing 106 on its own is formed
to create the
interior chamber 107. Within the interior chamber 107 and between the cover
108 and the spider
130 is a main bias member (not shown) that exerts a bias force on the cover
108 to push movable
sheave assembly 104 away from the fixed sheave 102 when a centrifugal force
that can counter
the bias force is not present.
[0023] Centrifugal forces, caused by the drive clutch 100 rotating, cause
rolling centrifugal
elements 150 position between an associated sheave ramp 109 within the housing
106 of the
movable sheave assembly 104 and a spider ramp 131 of the spider 130 to push
the movable
sheave assembly 104 towards the fixed sheave 102. Figure 2 illustrates a
portion of one of the
rolling centrifugal elements 150 that is position within rolling centrifugal
element pockets 162
between the sheave ramp 109 within the housing 106 of the of the movable
sheave assembly 104
Date Recue/Date Received 2023-02-06
and a spider ramp 131 of the spider 130. Drive clutch 100 will include a
plurality of rolling
centrifugal elements 150 and associated rolling centrifugal element pockets
162. In one
example, six ramp/roller pairs are used in a drive clutch with none of the six
being aligned 180
degrees from another.
[0024] Figure 3 illustrates a side perspective view of a rolling
centrifugal element 150 and
Figure 4 illustrates a cross-sectional side perspective view of the rolling
centrifugal element 150
in an example. The rolling centrifugal element 150 includes a centrally
positioned sheave ramp
roller 170. The sheave ramp roller 170 in this example is positioned between a
pair of spider
ramp rollers 160a and 160b. The sheave ramp roller 170 in this example,
radially extends out
from the axle 154 further than the spider ramp rollers 160a and 160b in this
example. In one
example, a diameter of the sheave ramp roller 170 is larger than the diameter
of the than the
spider ramp rollers 160a and 160b. Alternatively, in another example, the
sheave ramp roller
170 is smaller in diameter than the spider ramp rollers 160a and 160b with the
geometry of the
sheave ramp and spider ramps adjusted accordingly.
[0025] The sheave ramp roller 170 and spider ramp rollers 160a and 160b are
mounted on an
axle 154. The axle 154 in this example includes a mid-portion 154a upon which
the sheave ramp
roller 170 is mounted. The mid-portion 154a has a larger dimeter than side
portions 154b and
154c upon which the spider ramp rollers 160a and 160b are mounted in this
example. Thrust
washers 158a and 158b and retaining clips 161a and 161b retain the sheave ramp
roller 170 and
the spider ramp rollers 160a and 160b on the axle 154. An optional weighted
insert 152 may be
positioned within a central bore of axle 154.
[0026] Figure 5 illustrates an example of a spider 130 with six rolling
centrifugal elements
150. The spider 130 includes a base 133 with a central passage 134 that is
statically mounted on
the post 110. From the base 133, a plurality of spaced spider ramp arms 132,
that each include a
spider ramp 131, radially extend. Each ramp arm 132 includes a pair of spider
ramp portions
131a and 131b that are spaced by a non-contact portion 136. The spider ramp
rollers 160a and
160b of an associated centrifugal element 150 are designed to engage spider
ramp portions 131a
and 131b of an associated spider ramp arm 132 of the spider 130 while the
sheave ramp roller
170 of the associated centrifugal element 150 is positioned within the
associated non-contact
6
Date Recue/Date Received 2023-02-06
portion 136 of the spider ramp arm 132. Hence, in the example, the spider ramp
rollers 160a and
160b of each rolling centrifugal element 150 engages the spider while the
sheave ramp roller 170
of each rolling centrifugal element 150 does not contact the spider 130. This
is achieved in this
example by the spider ramp portions 131a and 131b having a first axial height
141 that is off set
from a second axial height 143 of the non-contact portion 136. In this
example, the first axial
height 141 is greater than the second axial height 143.
[0027] Figure 6 illustrates a cross-sectional end perspective view of an
example of the
housing 106 of the movable sheave assembly 104. Within the housing 106 is
formed, or
positioned, the plurality of the sheave ramps 109. The housing in this
example, includes a
central housing opening 105. The central housing opening 105 slidably receives
the post 110.
Also illustrated in this example is the positioning of the rolling centrifugal
elements 150
associated with each sheave ramp 109. The sheave ramp roller 170 of each
rolling centrifugal
element 150 engages an associated sheave ramp 109 while the spider ramp
rollers 160a and 160b
of each rolling centrifugal element 150 do not contact the associated sheave
ramp 109 in this
example.
[0028] Referring to Figure 7, a close-up view of a spider ramp arm 132 of
the spider 130, a
rolling centrifugal element 150 and the sheave ramp 109 within the housing 106
of the movable
sheave assembly 104 is illustrated. As illustrated, the center sheave ramp
roller 170 of the
rolling centrifugal element 150 engages the sheave ramp 109 within the
interior chamber 107 of
the movable sheave assembly 104 but not the spider ramp portions 131a and
131b. The
positioning of the central sheave ramp roller 170 places the sheave ramp
roller 170 within the
non-contact portion 136 of the spider ramp 131 between the spider ramp
portions 131a and 131b.
Further, the outside spider ramp rollers 160a and 160b of the rolling
centrifugal element 150
engage the spider ramp portions 131a and 131b of the spider 130 but not the
sheave ramp 109 of
the movable sheave assembly 104 as illustrated by gap 163. Hence, in the
example shown, the
spider ramp rollers 160a and 160b of the rolling centrifugal element 150
engage the spider 130
while the center sheave ramp roller 170 of the rolling centrifugal element 150
engages the
movable sheave assembly 104.
7
Date Recue/Date Received 2023-02-06
[0029] By splitting the roller contact surfaces between the spider 130 and
movable sheave
assembly 104, the centrifugal elements 150 can perform under rolling contact
vs sliding contact.
The rolling contact of the centrifugal elements 150 reduces friction in the
system and allows the
drive clutch 100 to respond easier to changes in vehicle dynamics. The result
is a better
performing CVT having consistent shift characteristics and improved
durability. Further, the
design provides for better drivability characteristics, disengagement
characteristics, back shifting
characteristics as well as less wear than known designs.
[0030] In one example, the sheave ramp roller 170 is pressed fitted on the
mid-portion 154a
of the axle 154 and the outside spider ramp rollers 160a and 160b are mounted
on the respective
side portions 154b and 154c of axle via thrust washers 158a and 158b and
retaining clips 161a
and 161b. In one example, the sheave ramp roller 170 and outside spider ramp
rollers 160a and
160b are made with an over-mold plastic. In another example, they are solid
polymer rollers.
The axle material may be varied to achieve a mass adjustment in an example
embodiment.
Further in one example, all rollers 160a, 160b and 170 are free to rotate in
relation to the axle. In
addition, in one example, the sheave ramp roller 170 is integral to axle 154.
Moreover, the
design allows the sheave ramp roller 170 to rotate in the opposite direction
than the outside
spider ramp rollers 160a and 160b.
[0031] In another embodiment, there are two sheave ramp rollers and one
spider ramp roller.
Further in this example, there are two ramp surfaces within the housing of the
movable sheave
assembly for each rolling centrifugal element and one ramp surface on each arm
of the spider.
Hence, other rolling centrifugal element configurations are contemplated to
achieve separate
engagement of the spider ramps and sheave ramps.
[0032] Referring to block diagram of Figure 8, an example vehicle 200
implementing a drive
clutch 100 described above is illustrated. The drive clutch 100 is part of a
CVT 204 that further
includes an endless looped member 211 (that may be a belt) and a driven clutch
206. The drive
clutch 100 is in operational communication with an engine 202 to receive
engine torque. The
driven clutch 206 is in operational communication with the drive clutch 100
via the endless
looped member 211 to selectively communicate torque between the drive clutch
100 and the
driven clutch 206.
8
Date Recue/Date Received 2023-02-06
[0033] The driven clutch 206 is in communication with a driveline that, in
this example,
includes a gear box 208. The vehicle 200 in this example includes a rear
differential 216 that is
in operational communication with the gear box 208 via rear prop shaft 212.
The rear
differential is in operational communication with rear wheels 224a and 224b
via respective prop
shafts 222a and 222b.
[0034] Further in this example, the vehicle includes a front differential
214 that is in
operational communication with the gear box 208 via front prop shaft 210. The
front
differential is in communication with the front wheels 220a and 220b via front
half shafts 218a
and 218b. Other vehicle configurations may use the drive clutch 100 described
above including,
tracked vehicles, as well as any other types of vehicles that employ a CVT
system.
[0035] An example of an arrangement where the spider ramp 331 is designed
to engage the
sheave ramp roller 170 while the spider ramp rollers 160a and 160b of the
rolling centrifugal
elements 150 engage sheave ramp portions 331a and 331b of a sheave ramp 309 is
illustrated in
Figure 9. As illustrated in the partial cross-sectional close-up view of a
moveable sheave
member of Figure 9, the sheave ramp roller 170 in this example is received in
a non-contact
portion 336 of the sheave ramp 309. Hence, different configurations of spider
ramps and sheave
ramps may be used to separately engage the sheave ramp roller 170 and spider
ramp rollers 160a
and 160b of the rolling centrifugal elements 150. Further as discussed above,
the rolling
centrifugal elements 150 may have a different configuration to separately
engage the spider
ramps and sheave ramps.
EXAMPLE EMBODIMENTS
[0036] Example 1 includes a drive clutch for a continuously variable
transmission. The drive
clutch includes a post, a fixed sheave, a movable sheave assembly, a plurality
of spaced sheave
ramps, a spider, and a plurality of roller centrifugal elements. The fixed
sheave is statically
mounted on an end of the post. The movable sheave assembly is slidably mounted
on the post.
The movable sheave assembly includes a housing that forms at least in part an
interior chamber.
The plurality of spaced sheave ramps are positioned within the interior
chamber of the housing
of the movable sheave assembly. The spider is received within the housing of
the movable
sheave assembly. The spider is statically mounted on the post. The spider
includes a plurality of
9
Date Recue/Date Received 2023-02-06
spaced radially extending spider ramp arms. Each spider ramp arm includes at
least one spider
ramp. The plurality of roller centrifugal elements are received within the
interior chamber of the
housing of the movable sheave. Each roller centrifugal element includes at
least one sheave
ramp roller and at least one spider ramp roller. The at least one sheave ramp
roller is configured
to engage one of an associated sheave ramp and associated spider ramp and the
at least one
spider ramp roller configured to engage another one of the associated sheave
ramp and
associated spider ramp.
[0037] Example 2 includes the drive clutch of Example 1, wherein each
spider ramp further
includes at least one spider ramp portion and a non-contact portion. The at
least one sheave
ramp roller of an associated roller centrifugal element is configured to be
positioned within the
non-contact portion of an associated spider ramp.
[0038] Example 3 includes the drive clutch of any of the Example 1, wherein
each spider
ramp further includes a pair of spider ramp portions and a non-contact
portion. The non-contact
portion is positioned between the pair of spider portions. The at least one
spider ramp roller of
an associated roller centrifugal element includes a pair of spider ramp
rollers. Each spider roller
of the pair of spider rollers engages one spider ramp portion of the pair of
spider ramp portions
of an associated spider ramp. The at least one sheave ramp roller of an
associated roller
centrifugal element is configured to be positioned within the non-contact
portion of an associated
spider ramp.
[0039] Example 4 includes the drive clutch of Example 3, wherein the pair
of spider ramp
portions have a first height that is offset from a second height of the non-
contact portion.
[0040] Example 5 includes the drive clutch of any of the Examples 3-4,
further including an
axle for each roller centrifugal element. An associated pair of spider ramp
rollers and sheave
ramp roller are mounted on each axle.
[0041] Example 6 includes the drive clutch of Example 5, further wherein
each axle includes
a central bore. A weight is positioned within the central bore.
Date Recue/Date Received 2023-02-06
[0042] Example 7 includes the drive clutch of any of the Examples 1-6,
wherein the at least
one sheave ramp roller of each roller centrifugal element extends radially
outward farther than
the at least one spider ramp roller.
[0043] Example 8 includes the drive clutch of any of the Examples 1-7,
wherein the at least
one sheave ramp roller and at least one spider ramp roller are free to rotate
independent of each
other on an axle.
[0044] Example 9 includes the drive clutch of any of the Examples 1-8,
further including a
cover coupled to the housing to form the interior chamber.
[0045] Example 10 includes a rolling centrifugal element for a clutch of a
continuously
variable transmission. The rolling centrifugal element includes an axle and at
least one sheave
ramp roller and at least one spider ramp roller mounted on the axle. The at
least one sheave
ramp roller is configured to engage one of an associated sheave ramp of a
movable sheave
assembly of the clutch and an associated spider ramp of a spider and the at
least one spider ramp
roller configured to engage another one of the associated sheave ramp and the
associated spider
ramp. The at least one sheave ramp roller is configured to rotate independent
of the at least one
sheave ramp roller.
[0046] Example 11 includes the rolling centrifugal element of Example 10,
wherein one of
the at least one sheave ramp roller and the at least one spider ramp roller
extends radially
outward farther than the other one of the at least one sheave ramp roller and
the at least one
spider ramp roller.
[0047] Example 12 includes the rolling centrifugal element of any of the
Examples 10-11,
wherein the at least one spider ramp roller includes a pair of spider ramp
rollers. The at least one
sheave ramp roller is configured to be positioned within the non-contact
portion of an associated
spider ramp.
[0048] Example 13 includes the rolling centrifugal element of any of the
Examples 10-12,
further including a weight insert received within a central bore of the axle.
[0049] Example 14 includes the rolling centrifugal element of any of the
Examples 10-13,
wherein the axle further includes a mid-portion, a first side portion and
second side portion. The
11
Date Recue/Date Received 2023-02-06
at least one sheave ramp roller is mounted on the mid-portion of the axle. One
spider ramp of
the pair of the spider ramps is mounted on the first side portion. Another
spider ramp of the pair
of the spider ramps is mounted on the second side portion. The mid-portion is
positioned
between the first side portion and the second side portion.
[0050] Example 15 includes the rolling centrifugal element of Example 14,
wherein the mid-
portion of the axle has a larger diameter than a diameter of the first and
second side portions of
the axle.
[0051] Example 16 includes the rolling centrifugal element of and of the
Examples 10-15,
wherein at least one of the at least one sheave ramp roller and the at least
one spider ramp roller
is rotationally mounted on the axle.
[0052] Example 17 includes a vehicle. The vehicle includes an engine to
produce engine
torque, a driveline and a CVT. The CVT includes a driven clutch and a drive
clutch. The driven
clutch is in operational communication with the driveline. The drive clutch is
in operational
communication with the engine. The drive clutch includes a post, a fixed
sheave, a movable
sheave assembly, a plurality of spaced sheave ramps, a spider, and a plurality
of roller centrifugal
elements. The fixed sheave is statically mounted on an end of the post. The
movable sheave
assembly is slidably mounted on the post. The movable sheave assembly includes
a housing that
forms at least in part an interior chamber. The plurality of spaced sheave
ramps are positioned
within the interior chamber of the housing of the movable sheave assembly. The
spider is
received within the housing of the movable sheave assembly. The spider is
statically mounted
on the post. The spider includes a plurality of spaced radially extending
spider ramp arms. Each
spider ramp arm includes at least one spider ramp. The plurality of roller
centrifugal elements
are received within the interior chamber of the housing of the movable sheave.
Each roller
centrifugal element includes at least one sheave ramp roller and at least one
spider ramp roller.
The at least one sheave ramp roller is configured to engage one of an
associated sheave ramp and
associated spider ramp and the at least one spider ramp roller configured to
engage another one
of the associated sheave ramp and associated spider ramp. An endless looped
member couples
torque between the drive clutch and the driven clutch.
12
Date Recue/Date Received 2023-02-06
[0053] Example 18 includes the vehicle of Example 17, wherein each spider
ramp further
includes a pair of spider ramp portions and a non-contact portion. The non-
contact portion is
positioned between the pair of spider portions. The at least one spider ramp
roller of an
associated roller centrifugal element includes a pair of spider ramp rollers.
Each spider roller of
the pair of spider rollers engages one spider ramp portion of the pair of
spider ramp portions of
an associated spider ramp. The at least one sheave ramp roller of an
associated roller centrifugal
element is configured to be positioned within the non-contact portion of an
associated spider
ramp.
[0054] Example 19 includes the vehicle of any of the Examples 17-18,
wherein the at least
one sheave ramp roller and at least one spider ramp roller are free to rotate
independent of each
other on an axle.
[0055] Example 20 includes the vehicle of any of the Examples 17-19,
wherein one of the at
least one sheave ramp roller and the at least one spider ramp roller extends
radially outward
farther than the other one of the at least one sheave ramp roller and the at
least one spider ramp
roller.
[0056] Although specific embodiments have been illustrated and described
herein, it will be
appreciated by those of ordinary skill in the art that any arrangement, which
is calculated to
achieve the same purpose, may be substituted for the specific embodiment
shown. This
application is intended to cover any adaptations or variations of the present
invention. Therefore,
it is manifestly intended that this invention be limited only by the claims
and the equivalents
thereof.
13
Date Recue/Date Received 2023-02-06
