Note: Descriptions are shown in the official language in which they were submitted.
CA 02406487 2002-10-17
BACKGROUND
Motorcyclists must periodically raise one of their vehicle's wheels in order
to
change tires or perform drive chain maintenance. Motorcycles equipped with a
two-
legged "center stand" facilitate such maintenance because, when parked, the
rear wheel is
typically supported above ground level. However, such center stands cannot be
used to
support the vehicle's front wheel offthe ground for tire changes or other
front-end
maintenance. Furthermore, high-performance motorcycles are usually equipped
with
only a "kickstand" or "side stand": a folding prop that pivots out from the
motorcycle
(typically from its left side). Side stands are compact and lightweight
however they
require ground support at both the front and rear wheels in order to achieve
stable support
geometry, thereby rendering both front and rear wheel maintenance difficult.
Various jacks have been devised for raising the wheels of motorcycles having
only a side
stand. Professional mechanics may use hydraulic platform lifts that raise the
motorcycle's entire midsection, thereby suspending both front and rear wheels
offthe
ground. A less expensive alternative is to use a "paddock stand" comprised of
a pair of
large curved levers joined into a unitary frame. The user engages both tips of
the
paddock stand underneath the motorcycle's rear swing arm assembly and then
levers the
rear wheel offthe ground. Manufacturers sometimes provide "spool" fixtures
projecting
from both sides of the swing arm assembly to facilitate engagement of such
paddock
stands. The paddock stand is effective however it is too bulky for
motorcyclists to carry
with them for roadside maintenance. Furthermore, its large frame structure is
expensive
and must be specially adapted to engage the rear swing arm dimensions of
different
motorcycles. Paddock stands may also be adapted to lift the front wheel,
either by lifting
both sides of the front axle or by lifting under the steering head. Front
paddock stands
are even more complex and costly than rear paddock stands.
When parked on its side stand, a motorcycle is supported fore-and-aft by its
front
and rear wheels and side-to-side by the tip of its side stand (typically
located on the
..~ .. _,........, ._. ...._..... , .....". ~..~"...,._...... _..._..... .....
_.._..,.......~.-,.._ .,~......,...~."......m..,".....-..."._..... ,. ..
CA 02406487 2002-10-17
motorcycle's left side). This triangular support geometry presents a simple
method of
raising either wheel. By lifting up and forward onto a point on the right side
of the
vehicle's rear-wheellswing-arm assembly, the entire motorcycle tilts forward
and further
over to the left, thereby lifting the rear wheel offthe ground. The same
general technique
can be used to lift the front wheel. Lift up and back onto the right front
portion of its
motor and the motorcycle will tilt backwards over the line between the rear
wheel and the
kickstand, thereby raising the front wheel offthe ground. To increase
stability, the
motorcycle can be prevented from rolling backwards or forwards; either by
chocking one
of its wheels or by lashing one of its brake lever controls.
This manual lifting maneuver costs nothing to perform however it has several
disadvantages: lifting either end of a motorcycle requires great physical
strength.
Furthermore, care must be taken to not lift the wheel so far that the
motorcycle's center
of gravity topples past the support offered by its kickstand and opposite
wheel.
An improvement to the tilting technique is to employ a prop member: simply
tilt
the motorcycle up and then prop up a raised portion to prevent the wheel from
falling
back down. Such a prop can be both compact and inexpensive: a simple wooden
stick
cut to an appropriate length will suffice. Once in place, such a prop permits
maintenance
work to be done at leisure however, lifting the motorcycle in order to insert
the prop
under either the swing arm or motor is still a strenuous task requiring great
dexterity to
perform safely. One person is typically required to tilt and hold up the
motorcycle while
another person inserts or removes the prop.
It is therefore an object of the present invention to provide an inexpensive
motorcycle jack that a single person can use to safely lift either end of a
motorcycle. It is
a further object to provide a motorcycle jack that is compact and light enough
to be
transported with the motorcycle. It is a further object to provide a
motorcycle jack that
includes versatile engagement fixtures adapted to fit a wide variety of
motorcycles as
well as small "ATV" style vehicles having three or four wheels. Still further
objects and
advantages of my invention will become apparent from consideration of the
ensuing
description and drawings.
SUMMARY OF THE INVENTION
A telescopic jack adapted to lift either wheel of a motorcycle by raising a
lifting
point located on the right side of said motorcycle towards the pivot line
formed between
the tip of the motorcycle's extended kickstand and the ground contact point of
one of its
wheels.
The telescopic jack assembly is comprised of a tube member engaged at its
upper
end to the motorcycle via a socketed engagement fixture fitted into the top of
said tube.
Said upper tube member threadingly receives a coaxial jackscrew, said
jackscrew being
threadingly engaged inside the tube member's lower end. In a preferred
embodiment,
only the bottom portion of said tube member is threaded, said threaded portion
being
included in a detachable threaded fixture that is fitted over the lower end of
a smooth-
bored tube member.
The pointed lower end of said jackscrew is engaged to the ground via a
socketed
foot member, said foot member also serving as a thrust bearing when said
jackscrew is
turned. The user engages the socket of the upper engagement fixture under a
bolt-head
fixture or similar protrusion on the motorcycle, said protrusion being a solid
lifting point
2
.. _ . ..._.,.w....~_...._..._. , ..
i
CA 02406487 2002-10-17
affixed to the motorcycle's right side. The substantially pointed lower end of
said
jackscrew is inserted in the foot member's socket and the assembly is then
oriented
vertically to form a telescopic lifting strut onto said lifting point. When
its jackscrew is
turned, said jack assembly telescopes, thereby raising the motorcycle's
nearest wheel off
the ground. Means for improving the jack's stability by blocking the
motorcycle's
wheels and adjusting its lean angle are also disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an oblique view of a conceptual motorcycle having the motorcycle
jack
positioned to lift its rear wheel.
FIG. 2 is an oblique view of a conceptual motorcycle having the motorcycle
jack
positioned to lift its front wheel.
FIG. 3 is a large-scale view of FIG. l, showing the motorcycle jack lifting
onto a fixture
located on the rear swing arm.
FIG. 4 is a large-scale view of FIG. 2, showing the motorcycle jack lifting
onto a fixture
located on the motor.
FIG. 5 is an exploded view of the motorcycle jack assembly.
FIG. 6 is a detail view illustrating the internal bores of tube thread fixture
15.
FIG. 7 is a detail view illustrating jackscrew 9.
FIG. 8a and 8b are detail views illustrating engagement fixture 16.
FIG. 9 is a detail view illustrating a cradle fixture used to engage the jack
onto vehicles
not easily fitted with suitable bolt-head fixtures.
FIG. 10 is an oblique view of an embodiment utilizing an engagement fixture
that
threadingly engages to the jackscrew and self centers under the motorcycle's
lifting point
via an engagement socket that is eccentric to the jackscrew's axis.
FIG. 11 is an oblique view of the cradle fixture illustrated in FIG. 9 engaged
to a frame
member of a motorcycle or All Terrain Vehicle.
FIG. 12 is an oblique view of a conceptual motorcycle having the motorcycle
jack
positioned to lift its front wheel and further including a tensioned cable
between the
kickstand and foot member to prevent side slipping of the motorcycle.
FIG. 13 is an oblique view of a conceptual motorcycle having a first
motorcycle jack
positioned to lift its front wheel and a second motorcycle jack positioned to
prevent side
slipping of the motorcycle.
3
CA 02406487 2002-10-17
FIG. 14 is an oblique view of a "shoe" fitted under the kickstand that
facilitates tethering
the jack to prevent side slipping of the motorcycle.
FIG. 15 is an oblique view of a stick-on fixture attached to the underside of
the swing
arm to provide a lifting point for the motorcycle jack.
DETAILED DESCRIPTION
FIG. 1 and FIG. 2 illustrate the present invention operatively engaged to a
motorcycle within a conceptual overview, said overview being comprised of the
jack
assembly 8, the motorcycle's front wheel 2, its rear wheel 1, its motor 3, its
deployed
kickstand 5 and its swing arm 6. A V-twin motor configuration is shown
conceptually
however the present invention is adaptable to a wide variety of engine and
frame
configurations. A host of motorcycle components such as seat, gas tank,
controls etc are
not illustrated, as they are not relevant to understanding the operating
principles of the
motorcycle jack.
In FIG. 1, bolt head 7 or similar lifting point, protrudes from the
motorcycle's
right side, aft of its center of gravity. When telescopic jack assembly 8 is
extended, said
lifting point raises the rear wheel as the motorcycle rotates about pivot line
100, drawn
between the ground contact points of front wheel 2 and kickstand 5.
Similarly in FIG. 2, bolt head 4 or similar lifting point protrudes from the
motorcycle's right side, forward of its center of gravity. When telescopic
jack assembly
8 is extended, the lifting point 4 raises the front wheel as the motorcycle
rotates about
pivot line 101, drawn between the ground contact points of rear wheel 1 and
kickstand 5.
While parkred on its kickstand 5, the motorcycle is tilted substantially
towards the
Left. If the motorcycle is moved closer to the vertical prior to engaging and
extending
jack assembly 8, its fully raised position will be more vertical, more stable
and more
comfortable to work on. Furthermore, the more vertical the motorcycle, the
more equal
its weight distribution will be onto kickstand 5 and jack assembly 8; thereby
reducing
bending forces in the kickstand and its supporting frame members. Parking on
sloped
terrain may provide adequate righting towards the vertical however a sloping
work
environment is not always available. Therefore, kickstand shim block 21 may be
provided for insertion under the tip of kickstand 5 to bring the motorcycle
closer to the
vertical prior to raising its wheel. Optional kickstand shim block 21 is
typically 1 to 3
inches high and may have a wedge shape that enables the user to make fine
adjustments
to the motorcycle's tilt angle.
To fi.~rther enhance stability, wheel-chock 22 may also be provided to prevent
any
forward or backward movement of the motorcycle while its front or rear wheel
is raised.
In a preferred embodiment, the functions of wheel-chock 22 and kickstand shim
block 21
are performed by a combined shim/chock block having a shape and size that
enables it to
adequately serve as either as a shim under kickstand prop 5 or as a wheel
chock in front
of wheel 2 or behind wheel 1.
When disassembled, jack assembly 8 is compact enough to be stored in the
motorcycle's toolkit however wheel chock 22 is a bulky part that detracts from
the jack's
portability. Therefore, an alternate means for immobilizing either wheel may
be provided
that is compact enough to carry in the motorcycle's toolkit. Said means for
immobilizing
the front wheel is comprised of an elastic lashing (not illustrated) that
permits the user to
4
CA 02406487 2002-10-17
bind the front brake lever against the handlebar in its "on" position. Said
means for
immobilizing the rear wheel is comprised of a bag (not illustrated) that the
user hangs
from the end of the rear brake pedal and loads with a weight such as gravel,
thereby
holding the lever in its "on" position.
FIG. 3 and FIG. 4 are larger scale views of FIG. l and FIG. 2 respectively.
The
jack assembly is comprised of tube member 13 engaged at its upper end to the
motorcycle via socketed engagement fixture 16, said fixture being fitted into
the top of
said tube. Tube member 13 threadingly receives coaxial jackscrew 9, said
jackscrew
being engaged inside the lower portion of said tube's bore (thread detail not
illustrated).
Internally threaded tube 13 and its socketed upper end 16 may be formed as a
single
monolithic piece (not illustrated).
For ease of manufacture as well as to enable disassembly for compact storage,
the
socket function, the support function and the threaded jacking function may be
provided
by three discrete components rather than a single monolithic piece. Referring
to the
embodiment detailed in FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7, FIG. 8a and
FIG. 8b, the
bore of tube member 13 is not threaded and its smooth bore is slightly larger
than the
outer thread diameter of jackscrew 9, thereby permitting unconstrained
relative rotation
but fully constraining any bending moments applied to the mated jackscrew and
tube
member.
Tube thread fixture 15 is engaged to the lower end of tube member 13. To
effect
said engagement, a smooth cylindrical bore 111 is formed axially in the upper
portion of
tube thread fixture 1 S such that it may be snuggly fitted over the lower end
of said tube
member to a depth sufficient to constrain both axial and bending loads.
Typically, tube
member 13 and tube thread fixture 15 are disengaged for storage by simply
pulling them
apart. Threaded or magnetic means for mating the two parts may also be used
(not
illustrated).
A threaded bore 110 matching the thread on jackscrew 9 is formed axially
through the lower portion of tube thread fixture 15 such that, jackscrew 9 may
threadingly telescope with respect to said fixture and the bore of its engaged
tube member
13. The outer surface of fixture 15 may be a textured cylinder (not
illustrated), thereby
providing a high friction surface that the user can grip to prevent rotation
when jackscrew
9 is turned. Alternatively, the fixture's outer form may be mufti-faceted as
shown,
thereby providing both a comfortable handhold and suitable engagement surfaces
for
holding with a wrench.
Multiple instances of tube member 13 may be supplied with jack assembly 8,
each
of said tube members being cut to a different length. When assembling jack 8,
the user
may thereby select a tube that provides the correct jack extension to suit the
particular
lifting task being undertaken. For example, in FIG. 1 and FIG. 3, a short tube
member 13
is used in jack assembly 8, thereby permitting the jack to fit onto lifting
point 7 located
on the low swing arm assembly 6. In FIG. 2 and FIG.4, a longer tube member 13
is used
in jack assembly 8, thereby permitting the jack to fit onto li$ing point 4
located high up
on the front of motor 3. In a preferred embodiment, the difference in length
between the
longer and shorter of said tube members 13 is less than the usable travel of
fixture 15
along jackscrew 9, thereby permitting continuous adjustment of the jack's
height
throughout its total range.
CA 02406487 2002-10-17
Jackscrew 9 is typically pierced transversely near its lower end by at least
one
torque lever bore 12. Torque lever 11 is a bar fitted through said bore,
thereby permitting
the user to turn jackscrew 9 against considerable axial load. Bore 12 is
typically sized
such that a common screwdriver may be inserted through it to apply the
required torque,
thereby eliminating the need to carry dedicated torque lever 11 as part of
jack assembly 8.
Multiple instances of torque lever bore 12 may be provided, thereby permitting
the user
to choose a comfortable height at which to apply torque to the jack. Other
hand-operated
means for applying torque to jackscrew 9 may be used. For example, a knob
might be
incorporated near the lower end of jackscrew 9 or a hexagonal portion might be
provided
to facilitate turning it with a wrench (not illustrated).
The lower end of threaded jackscrew 9 has a substantially pointed shape with a
rounded tip, thereby forming thrust-bearing point 10. Bearing point 10 engages
into
rounded socket 20, said socket being formed in the upper surface of foot
member 19.
The somewhat rounded tip of bearing point 10 forms a ball and socket joint
that permits
said jackscrew to rotate at various orientations with respect to foot member
19. Said ball
and socket joint's small contact area also serves to reduce friction when the
jackscrew is
turned under heavy axial load. Typically, foot-member 19 is substantially disk
shaped,
having a diameter sufficient to adequately distribute the motorcycle's weight
onto the
ground and having socket 20 formed concentric to the disk.
The lower surface of foot member 19 may include a textured surface I 14 to
increase ground friction. The upper surface of said foot member may include
graphical
user instructions that indicate which direction to turn the jackscrew in order
to raise or
Lower the motorcycle (not illustrated).
Other embodiments of ball and socket joint 10, 20 may be used. For example,
the
lower end of jackscrew 9 might terminate in a spherical protrusion that is
rotateably
captured within socket 20. Such an embodiment (not illustrated) provides the
convenience of permanently mating components 9 and 19 within jack assembly 8.
Another embodiment that facilitates assembling and using said ball and socket
joint
utilizes a magnet centrally embedded in foot member 19 that attracts the
rounded bottom
end 10 of jackscrew 9 (also not illustrated).
The open, upper end of tube member 13 receives engagement fixture 16. Said
engagement fixture is comprised of a substantially cylindrical body having a
narrow
engagement portion 112 formed with a diameter that fits snuggly within the
upper bore of
tube member 13 and a wide engagement portian 1 I6 formed with a diameter that
is
somewhat too large to fit inside said bore. Engagement socket 17 is formed
into the
upper surface of fixture 16, said socket having a dished shape suitable for
self centering
engagement under a protruding bolt head or similar lifting point (4, 7). FIG.
8a illustrates
an engagement fixture having a first narrow portion I 12 that inserts directly
into the open
upper end of tube member 13 where it is retained by friction. Socket 17 is
formed in the
upper surface of second narrow portion I 17, thereby permitting the fixture to
be inserted
with either its socketed end exposed or its flat end exposed. Bore 118 may be
formed
axially through fixture 16, thereby permitting it to be selectably affixed to
the cradle
fixture described below and illustrated in FIG. 9. FIG. 8b illustrates an
engagement
fixture having threaded fixation means rather than fictional fixation means.
Magnetic
fixation means (not illustrated) may also be used. In FIG. 8b, it is evident
that, if bore
6
CA 02406487 2002-10-17
118 is provided for selectably affixing a cradle fixture, the mating surface
between said
parts will be the socketed end rather than the flat end adjacent threaded
portion 112.
Tube member 13 and engagement fixture 16 may also be formed as a single
monolithic piece (not illustrated), comprised of a tube with one closed end
and a socket
formed in the outer surface of said closed end.
FIG. 3 illustrates engagement fixture 16 lifting onto rear lifting point 7. In
this
particular case, lifting point 7 is comprised of a standard, hexagonally
headed bolt
protruding from a threaded hole already provided with the motorcycle. Standard
Allen
head bolts may also be used (not illustrated). The projecting portion of said
bolt is
affixed using one or more locknuts, such that lifting point 7 has sufficient
clearance from
swing arm 6 to permit reliable engagement of its head portion within socket
17. The
illustrated bolt hole in swing arm 6 is often supplied on sport-oriented
motorcycles for
affixing the "spools" used to engage a paddock stand. An uninstalled example
of such a
spool 24 is illustrated near the bolt head used to form lifting point 7. The
engagement
socket 17 used to capture lifting point 7 may have a radius of curvature
sufficient to self
center onto such a spool's outer edge as well as onto a conventional bolt head
used to
form lifting point 7 (see spool 24 in FIG.3).
Other suitable sites for installing rear lifting point 7 may be found on
typical
motorcycles. For example; the rear brake typically includes an anti-torque arm
along the
right side of the motorcycle, its front end being bolted through a pivot point
on the swing
arm and its rear end being bolted through the brake caliper housing (not
illustrated). Both
ends of said torque arm may be suitable sites for installing a bolt or similar
fixture to
form rear lifting point 7. Similarly, a typical motorcycle's exhaust system
(not
illustrated) includes several mounting bolt locations behind the motorcycle's
center of
gravity suitable for receiving an extended bolt and locknut for use as lifting
point 7.
FIG. 4 illustrates engagement fxture 16 lifting onto front lifting point 4. In
this
illustration, lifting point 4 is comprised of a specially manufactured,
spherical-headed
bolt and locknut that provides a smooth mating surface between the jack and
motorcycle.
Motorcycle motors typically include a bolted exhaust header clamp at the
illustrated
location. An exhaust header bolt or similar fastener located forward of the
motorcycle's
center of gravity might therefore be replaced with a longer bolt having either
a
conventional head or spherical head (as illustrated), thereby forming tilting
point 4 that
can be captured within dished socket 17. If the motorcycle utilizes studs
instead of bolts
to affix its exhaust header, then any exposed stud threads may be capped with
an 'acorn
nut" or similar fixture to act as a rounded lifting point 4. Other locations
forward of the
motorcycle's center of gravity are also suitable for receiving a bolt that
could serve as
lifting point 4. For example, front motor-mounts are typically bolted to a
threaded or
smooth bore through the frame. Various engine cover bolts might also be used
to adapt
the motorcycle for use with the present invention (not illustrated).
FIG. 15 illustrates an embodiment of lifting point 4 or 7 that can be used to
engage the jack assembly to a motorcycle having no bore suitable for receiving
a bolt
fixture. Fixture plate 123 includes a domed protrusion on its lower side for
engagement
into the upper socket of said jack. A "peel-and-stick" adhesive backing is
typically
provided to facilitate mounting plate 123 to a lower surface of the motorcycle
such as the
underside of swing arm 6.
7
CA 02406487 2002-10-17
Other variants of the bolt protrusion that comprises lifting points 4 or 7 may
be
used. For example, a large washer with a suitable eccentric protrusion might
be captured
under a rear wheel axel bolt or a front engine-mounting bolt (not
illustrated). Some
motorcycles have a hollow rear axle that permits an extension plug to be
temporarily
inserted to act as a lifting point (not illustrated). To provide a motorcycle
jack that is
adaptable for use with a wide variety of different motorcycles, an embodiment
of jack
assembly 8 includes a selection of suitable bolt fixtures that can be
installed to serve as
lifting points 4,7 on virtually any motorcycle.
The illustrated embodiments of lifting points 4 or 7 are typically retrofitted
to
existing motorcycles. However, newly manufactured motorcycles may also be
equipped
and optimized for use with the present invention. To accomplish this, the
components
that comprise the jack assembly are included in the motorcycle's standard
toolkit. Lifting
points (not illustrated) may also be integrated into the motorcycle's swing
arm and motor
during their manufacture. For example, the engine casing and right swing arm
may be
modified to provide fore and aft lifting points similar in configuration to
lifting point 123
shown in FIG. 15. The location of kickstand 5 may also be located with respect
to said
lifting points such that the jack's support geometry is optimized for lifting
either front or
rear wheel with minimum effort.
In another similar embodiment (not illustrated), the order of components in
the
jack assembly is inverted such that the threaded jackscrew telescopes from the
upper end
of the tube member rather than from its lower end. The dished engagement
socket is
formed in the jackscrew's upper end and the tube member's lower end engages
the
ground. Since the lower portion of the jack does not turn, the tube member's
lower end
may rest directly against the ground without the need for a thrust bearing. To
improve
weight distribution onto the ground, the tube's lower end may be closed or
include an
articulated foot member similar to that shown in FIG. 3. While slightly
simpler than the
preferred embodiment described above, this embodiment is somewhat less
desirable
because its dished socket rotates with respect to the lifting point on the
motorcycle. If the
lifting point is a hex headed bolt then there will be undesirable friction and
scoring where
it rubs inside the dished socket. Therefore, use of a ball-headed bolt such as
illustrated in
FIG. 4 is typically required in order to achieve smooth operation. This
inverted
embodiment also requires larger diameter components in order to mate with
typically
sized lifting point bolts.
Certain motorcycles are not equipped with any boltholes suitable for
conversion
to lifting point 4 or 7. In such cases, a cradle embodiment of engagement
fixture 16
(illustrated in FIG. 9) may be used. Cradle engagement fixture 16 may include
a
threaded hole 118 that permits cradle adaptor 25 to be affixed to its lower
surface. Cradle
adaptor 25 is a detachable platform or "U" shaped member having dimensions
suitable
for fitment under a motorcycle's swing arm or similar frame member. To insure
good
mating to the motorcycle, the top of cradle 25 may include a layer of
cushioning material
such as rubber (not illustrated).
In order to facilitate engagement to different types of motorcycle, the shape
of
cradle 25 may deviate somewhat from the orthogonal co~guration illustrated in
FIG. 9.
For example (not illustrated), a socket indentation may be formed on the
cradle's main
upper surface to form a combination "cradle/socket". The socket portion of
this
cradle/socket may be engaged onto lifting points such as bolt heads as
described above
8
CA 02406487 2002-10-17
while the U shaped cradle portion may be used to engage under tubular members
such as
certain swing arms. Another variation of cradle 25 (not illustrated) is to
provide a more
rounded cradle shape having concentric side ridges, thereby permitting the
cradle to
securely engage onto the raised edge of a common paddock stand spool.
Referring now to FIG. 11, the cradle embodiment of engagement fixture 16 also
permits the motorcycle jack to be used to raise a wheel of other vehicles such
as three or
four wheeled All Terrain Vehicles. To raise the wheel of an ATV, the user
engages
cradle fixture 25 under the vehicle's axle 115 near one of its wheels and then
extends the
jack assembly as described above.
FIG. 10 illustrates an alternate embodiment in which the motorcycle's lifting
point engages the jack assembly at a location that is eccentric to the
jackscrew's axis.
Lifting platform 26 is a cantilevered platform having a threaded bore that
engages to the
threads on jackscrew 9. Dished socket 17 is formed in the upper surface of
lifting
platform 26 and self centers under the motorcycle's front or rear lifting
point 4,7.
Referring now to FIG. 12: if the axis of the jack assembly is not vertical
when
lifting onto the motorcycle, the tip of kickstand 5 may slide sideways in
response to the
horizontal component of the force exerted by the jack as it is extended. To
prevent such
side-slippage, tether cable 102 may be provided having loop 103 and 105 formed
at either
end. Alternatively, a chain (not illustrated) may be used having large links
that serve as
end loops 103 and 105. Foot member 19 includes post 104 protruding from its
upper
surface. Post 104 may be an integral part of foot member 19 or else a
removable
component comprised of a bolt threaded into a hole in said foot member. To
prevent side
slippage, the user engages loop 105 around the tip of kickstand 5 and loop 103
around
post 104. As the jack assembly is extended and the motorcycle starts to
sideslip, tension
in tether cable 102 prevents the motorcycle from slipping further away from
foot member
19, thereby arresting the side-slippage and insuring reliable lifting of wheel
2.
The shape of the tip of kickstand 5 varies substantially from one motorcycle
to the
next and some models are not easily secured within tether loop 105. FIG. 14
illustrates
kickstand riser block 119 that also facilitates tethering different kickstands
to the jack.
Riser block 119 may include a plurality of apertures 121 in its upper surface
that receive
stop-pin 120, said pins protruding above the top surface of said riser block.
By
selectively inserting a plurality of stop-pins I 20 near the outboard edge of
riser block
119, the user configures a barrier that prevents the tip of kickstand 5 from
sliding off said
edge. Another stop pin 120 is located on riser block 119 where is effectively
serves as an
engagement pin over which loop 105 is placed to tether kickstand 5 to foot
member 19.
Ground engagement spikes 122 may be provided to improve the traction of riser
block
I I9. In many cases, the inclusion of such spikes will improve the traction of
riser block
119 such that tethering kickstand 5 to the jack assembly to prevent side
slippage is not
required.
FIG. 13 illustrates an alternate method of preventing side-slippage. Second
jack
assembly 106 is used in conjunction with first jack assembly 8. Jack assembly
106 is
shown engaged to a lower lifting point (not visible) rather than the lifting
point 4 used by
jack assembly 8 however any jack placement that forms a triangular support
geometry
will suffice. As both first and second jack assemblies 8, 106 are extended,
side forces are
balanced and front wheel 2 is raised without any side-slippage.
9
CA 02406487 2002-10-17
Side-slippage problems are simply unconstrained motion due to a combination of
Iow friction between the tip of kickstand 6 and the ground, coupled with too
large a
horizontal force vector imparted by jack assembly 8. The tethering means
described
above effectively constrain the tip of the kickstand from sliding however said
means
require expensive and cumbersome components. A simpler, more compact and more
cost-effective means of constraining the kickstand from sliding may be to
provide a high-
friction pad (not illustrated) that the user places under the kickstand's tip.
The upper and
lower surfaces of said pad are made of high friction material such as rubber
or sand
paper, thereby constraining the kip of kickstand 5 from slipping. Furthermore,
to reduce
the side force applied onto the motorcycle, the user is instructed to orient
jack assembly 8
near the vertical, thereby minimizing the jack's horizontal force vector.
If the motorcycle jack is being incorporated into a newly manufactured
motorcycle, the tip of kickstand 5 may be shaped to aid in the prevention of
side-slipping
(not illustrated). To accomplish this, the Iower surface of the kickstand may
include a
ground engagement spike and an engagement post may project at an appropriate
angle to
receive loop 105, thereby performing the functions of riser block 119 shown in
FIG. 14.
The preceding embodiments all use a threaded jackscrew as the telescoping
mechanism that lifts the jack's upper engagement socket away from its lower
foot
member. In another embodiment (not illustrated) the telescoping mechanism is a
hydraulic ram coupled at its upper end to an engagement socket and at its
lower end to a
foot member.
This description contains much specificity that should not be construed as
limiting
the scope of the invention but merely provides illustrations of some of its
embodiments.
Thus the scope of the invention should be determined by the appended claims
and their
IegaI equivalents rather than by the examples given.
....,... . ...........~"..._ __..._. . .... ... ...._.._.. .....,.._....__,...
... . ....
