Note: Descriptions are shown in the official language in which they were submitted.
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1NHEEL SUSPENSION SYSTEM FOR IN-LINE ROLLER SKATE
FIELD OF THE INVENTION
The present invention relates to in-line roller skates and more particularly
to
an adaptive wheel suspension system that permits the skate's wheels to deflect
in the
vertical plane.
EACKGROUND OF THE INVENTION
In-line roller skates are well known in the art. The typical skate comprises a
boot portion and a chassis connected to the boot's sole for mounting typically
four
longitudinally aligned wheels. The wheels' axles are rigidly mounted to the
chassis
and as a result transmit considerable shock and vibration to the skater, with
debilitating effects. Two approaches have been taken to shock absorption, one
wheel based and the other chassis based. Wheel based solutions include the use
of softer wheels (e.g. 72A to 74A durometer) or dual durometer wheels having
an
inner core of relatively softer material for shock adsorption and enhanced
rebound.
Chassis based solutions involve the use of mounts that permit some vertical
movement of the wheels or the use of a shock absorber between the wheels and
the
boot, or a combination of both.
Soft wheels provide greater comfort but at the expense of speed. Dual
durometer wheels are effective, but the amount of shock adsorption is
nevertheless
limited. Chassis that allow the wheels to deflect vertically are known, for
example
from U.S. Patent Nos. 5,582,418, 5,704,620 and 6,045,142. Each of these
chassis
also incorporate some sort of resilient shock absorbers such as springs in the
case
of Patent Nos. 5,582,418 and 5,704,620 and rubber bumpers 26 and 26' in the
case
of U.S. Patent No. Ei,045,142. Earlier chassis solutions have gained limited
commercial acceptance. Their complicated structure makes them expensive,
failure
prone and heavy. As well, the manner in which the wheels are suspended limits
their
adaptability to irregularities in the surface being traversed. U.S. Patent
5,704,620
teaches a suspension based an an elliptical spring that allows the wheels to
deflect
independently, but the overall suspension is complicated and vulnerable given
the
abuse such skates normally receive. In U.S. Patent 5,582,418, the wheels. are
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bogeyed, but into front and back pairs, which limits flexibility, particularly
during
manoeuvres, when independent movement particularly of the front and back
wheels
relative to the two interior wheels is desirable.
SUMMARY OF THE INVENTION
The present invention provides an improved chassis for an in-line roller skate
with a suspension for the wheels that permits a greater degree of independent
movement for each wheel to reduce shock and increase stability and
manoeuverability, while at the same time minimizing the number of wear and
maintenance susceptible parts.
Accordingly, it is an object of the present invention to provide a wheel
suspension system that obviates and mitigates from the disadvantages of the
prior
art.
It is a further advantage of the present invention to provide a wheel
suspension
system that reduces shock and vibration without the use of resilient shock
absorbing
means.
It is a further object of the present invention to provide a wheel supporting
suspension that is adaptive to irregularities in the skating surface.
According to the present invention then, there is provided a suspension for
the
wheels of an in-line roller skate, comprising a frame member connectable to
the boot
of the skate, said frame member having a pair of parallel spaced apart rails
extending
in the longitudinal direction of the skate; a bogey for supporting at least
one of the
skate's wheels, the bogey being suspended to be pivotable about a horizontal
axis
relative to said frame member; and beam members for supporting the skate's
leading
and trailing wheels, pairs of said beam members being pivotably connected at
one
end thereof to said bogey, rotatably supporting one of said wheels adjacent
the other
end thereof and being pivotably connected to respective ones of said rails at
a point
intermediate said ends of said beam members.
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BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present invention will now be described in
greater detail and will be better understood when read in conjunction with the
following drawings in which:
Figure 1 is a side elevational view of an in-line roller skate with the
present
wheel suspension system;
Figure 2 is a side elevational view of a beam member forming part of the
suspension;
Figure 3 is a side elevational view of a bogey member forming part of the
suspension;
Figure 4 is a side elevational view of a frame member forming part of the
present suspension;
Figure 5 is a perspective view of the frame member of Figure 4;
Figure 6 is a side elevational view of the beam and bogey members
assembled together;
Figure 7 is a plan view of the sub-assembly of Figure 6;
Figure 8 is a plan view of the beam, bogey and frame members assembled
together with the frame's top plates removed for greater clarity;
Figure 9 is a side elevational view of the suspension in operation;
Figure 10 is a side elevational view of the suspension traversing a concave
surface;
Figure 11 is a side elevational view of the suspension traversing a flat
surface;
Figure 12 is a side elevational view of the suspension traversing a convex
surface;
Figure 13 is a side elevational view of an alternative wheel suspension
system;
Figure 14 is a side elevational view of the beam of the suspension of Figure
13;
Figure 15 is a side elevational view of the bogey of the suspension of Figure
13;
Figure 16 is a side elevational view of the frame of the suspension of Figure
13;
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Figure 17 is a side elevational view of the suspension of Figure 13 in
operation;
Figure 18 is a side elevational view of the slot of Figure 13 with a braking
mechanism; and
Figure 19 is a side elevational view of the slot of Figure 13 with an
alternative
braking mechanism.
DETAILED DESCRIPTION
With reference to Figure 1, the present invention provides an in-line roller
skate 1 having a boot 2 and a chassis 3 connected to the boot for supporting
the
usual compliment of four longitudinally aligned wheels 5. In the embodiment
shown,
the wheels are connected to the chassis in the usual manner using countersunk
axle
bolts 7 that thread into an axle pin (not shown) extending through the wheel.
The
wheels themselves may also be conventional consisting of an outer tire 11, a
hub 12
and a bearing assembly 13 disposed annularly between the axle pin and the hub
which allows the wheel to rotate freely.
In the embodiment shown, the chassis additionally includes a heel plate 15
and a toe plate 16 for connecting the chassis to the sole of boot 2 using
rivets, screws
or other fastening means.
The structure of the wheels, their mounting for rotation and the connection of
the chassis to the boot are all conventional and will not therefore be
described in
further detail.
The present suspension system includes three principle components, namely
a beam 20 for mounting each of the front and rear wheels, a bogey 30 for
mounting
the two inner wheels and a frame 40 that supports the beams and bogeys and
which
is adapted by means of the heel and toe plates for connection to the boot. The
beam
and the bogey are paired on opposite sides of the wheels and are mirror images
of
one another in shape and size.
Beam 20 is shown in Figure 2. The beam shown is the one located at the front
of the skate to support the leading wheel. The beam used at the rear of the
skate will
usually be a mirror image in shape and size although this is neither essential
nor
necessary.
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Beam 20 is dog-legged in shape defining two arms 21 and 22. A countersunk
hole 23 is formed at the end of arm 21 for an axle bolt that connects the
wheel.
Another hole 24 is formed adjacent the end of arm 22. As will be described in
greater
detail below, this hole is for a pin member 27 that pivotably connects the
beam to
bogey 30 as shown most clearly in Figure 5. At the beam's apex is a third hole
25 for
another pin member 28 that pivotably connects the beam to frame 40, as will
also be
described in greater detail below.
The orthogonal distance X between a horizontal center line drawn through
holes 23 and 25 is selected to provide adequate clearance between the wheel
and
the chassis and so that the axial center line of the wheel's axle aligns with
the axially
center line of the three remaining wheels when arranged on a flat surface as
shown
in Figure 5.
Bogey 30 is shown in Figure 3. The bogey is formed with oppositely extending
arms 31 and 32. Adjacent the ends of each arms are countersunk holes 33 and 34
for the axle bolts connecting the skate's two inner wheels to the bogey. The
bogey
includes two additional holes 35 and 36. Hole 35 receives the pin 27 used to
connect
leading beam 20 and hole 36 receives the other pin 27 used to connect trailing
beam
30 to the bogey.
The orthogonal distance Y between horizontal center lines drawn through
holes 35 and 36 and holes 33 and 34, respectively, is chosen to provide
adequate
clearance between the wheels connected to the bogey and the chassis and so
that
the axles of the two bogey wheels align horizontally with the axles of the
leading and
trailing wheels when the skate is on a flat surface.
Frame 40 is shown in Figures 4 and 5. The frame consists of a pair of
parallel,
horizontally aligned mirror image rails 41 maintained in fixed spaced apart
relationship by toe plate 16 at the front and heel plate 15 at the rear. The
two plates
are fixedly connected to the rails such as by welding if the rails are made of
metal,
or formed integrally therewith if the frame is injection molded. Spacing
between the
rails is also maintained by pins 28 used to pivotably connect beams 20 to the
rails as
will be described in greater detail below.
To enable the present suspension to function as the wheels deflect vertically
alignment when traversing irregularities in the skating surface, the beam and
bogey
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mechanism must be able to lengthen and shorten in response. This is
accommodated by obround apertures or slots in the rails which allow the pins
that
connect the bogeys and beams to move in response to vertical movement of the
wheels. The length of these slots limits the amount of deflection so that the
wheels
are not allowed to move into frictional contact with the bottom of the boot or
with one
another.
With particular reference to Figure 4, each rail is formed with four apertures
with the apertures in one rail having the same dimensions and orientation and
being
in horizontal axial alignment with the apertures in the other. The apertures
in one rail
only will therefore be described in detail.
Forwardmost aperture 43 is an obround slot with its longitudinal axis aligned
in the horizontal plane of the frame. The aperture is dimensioned to allow the
pin 28
connecting beam 20 to side rail 41 approximately 1.6 millimetres of movement.
Aperture 44 is also an obround slot and is oriented with its longer axis
aligned
at an angle ~3 of approximately 3° to the vertical tilting towards the
rear of the frame.
The aperture is dimensioned to allow the pin 27 connecting bogey 30 to the
rail
approximately 5 millimetres of movement.
Aperture 45 is again an obround slot with its longer axis aligned at an angle
a of approximately 3° to the vertical tilting towards the front of the
frame: The
aperture is dimensioned to allow the pin 27 connecting bogey 30 to the frame
approximately 5 millimetres of movement.
Finally, aperture 46 adjacent the rear of the frame is circular in shape and
as
a result, the pin 28 connecting rear beam 20 permits rotation but does not
itself move
laterally in any direction.
As will be appreciated, the skate's leading wheel pivots around pin 28 in
aperture 43, the second wheel pivots around the pin 27 in aperture 44, the
third wheel
pivots around the pin 27 in aperture 45 and the trailing fourth wheel pivots
around pin
28 in aperture 46. Each wheel is allowed a maximum radial motion of
approximately
5° but this figure may be varied for different uses and construction of
the suspension.
Reference will now be made to Figure 9 which schematically shows pins 27
and 28 in their respective apertures for greater clarity.
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As the front wheel is deflected upwardly, pin 28 in slot 43 moves rearwardly,
pin 27 in slot 44 moves downwardly and pin 27 in slot 45 moves upwardly. As
the
second wheel encounters the surface irregularity, it moves upwardly and the
first and
third wheels move downwardly. In this way, the wheels' sequence over the
surface
irregularity to minimize shock transmission to the skater. As well, during
manoeuvres
the wheels automatically adjust themselves vertically depending on the angle
of the
skate relative to the ground. For example, when the skater is leaning into a
turn, the
two inner wheels on bogey 30 lower and the two outer wheels on beams 20 rise
to
allow a tighter turn and to provide more wheel contact with the ground for
greater
speed.
The differences in the shape and orientation of apertures 43, 44, 45 and 46
results in the two bogey wheels moving in response to a deflection of either
the
leading or trailing wheel, however, a deflection of the leading wheel does not
result
in any responsive deflection of the trailing wheel, and vice versa.
Reference will now be made to Figures 1 and 6 to 8 for purposes of describing
the assembly of the suspensian in greater detail. Reference will be made first
to
Figures 6 and 7 showing the sub-assembly of beams 20 and bogey 30.
Beams 20 are arranged to the outside of bogey 30 so that apertures 24 align
with holes 35 in the bogey for the insertion of pins 27. Each pin 27 consists
actually
of a number of parts. The first is a spacer bearing 60 shown as a breakaway in
Figure 8. The bearing, which is advantageously made of nylon, teflon or some
other
durable, low friction material, includes a cylindrical pin 62 and a contiguous
flange 63.
The pin is inserted first through hole 35 in bogey 30 and then through hole 24
in
beam 20 until flange 63 bears against the bogey's side wall. The sleeve is
long
enough to extend through both the bogey and the beam and into aperture 44 in
frame
rail 41 as will be described below. The outer diameter of the sleeve is equal
to the
diameters of holes 35 and 24 to eliminate any play. The diameter of the sleeve
is
smaller however than either the major or minor diameters of aperture 44 in the
rail to
that the sleeve can move up and down and, to a lesser extent, from side to
side in the
aperture. A low friction washer 66 is placed around the sleeve on either side
of beam
20.
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Reference will now be made to Figures 1 and 8 showing the assembly of the
beam-bogey sub-assembly to frame 40. In Figure 8, heel and toe plates 15 and
16
have been removed for greater clarity.
The beam-bogey sub-assembly fits between rails 41 of frame 40. The
protruding ends of pins 62 are received into apertures 44 and 45. The pins are
each
internally threaded for connection to threaded bolts 68. A pair of washers 70
and 71
are disposed around each bolt outside of rail 41. Inner washer 71 is
preferably a
plastic low friction washer and the outer washer 70 is metallic or otherwise
sufficiently
strong to withstand compressive loads as bolt 68 is tightened. This
arrangement
allows bolts 68 to be securely tightened to the pins of spacer bearings 60 but
at the
same time allows the pins and 'the bolts to slidably move within the scope
permitted
by apertures 44 and 45. Bolt 68 and its connection to pin 62 completes each of
pins
27.
Holes 25 in beams 20 align with apertures 43 and 46 in rails 41 for the
installation of pins 28. As with pins 27, pins 28 are a collection of parts.
These
include a cylindrical spacer 72, internally threaded at each of its ends,
which is placed
between beams 20 in alignment with holes 25. Shoulder bolts 74 are inserted
through apertures 43/46 in rails 41 and threaded into the ends of the spacers.
The
shoulder bolts include a flanged head 75, a cylindrical shoulder 76 and a
threaded
pin 77. The diameter of shoulder 76 is substantially equal to the diameter of
circular
aperture 46 in rail 41 so there is no play in the connection which is
therefore limited
to pivoting movement. The diameter of the shoulder is also substantially equal
to the
lesser diameter of slot 43 in 'the rail to permit the shoulder bolts to move
in the
longitudinal direction of these apertures, but not laterally relative thereto.
Low friction
washers 79 are placed as shown in Figure 8 to allow the shoulder bolts to
tighten
securely while still permitting them to slidably move in slots 43.
The specific means described above for connecting the components of the
suspension together are exemplary in nature and other means for accomplishing
the
same end will occur to those skilled in the art.
An alternative suspension is shown in Figures 13 to 17. As before, the
suspension comprises three principle components, a beam 120 shown in Figure
14,
a bogey 130 shown in Figure 15 and a frame 140 shown in Figure 16. The
principles
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of operation and function of this embodiment are similar to those of the
previously
described embodiment and the following description will therefore be confined
to the
differences between the two.
With reference to Figure 14, each beam 120 is arcuate in shape and has a first
hole 122 for a wheel mounting axle bolt, a second hole 123 for a pivotable
connection
to bogey 130 and at least one additional (third) hole 124 for a shoulder
bolt/bearing
sleeve pin 128 used to pivotably connect each beam to frame 140.
With reference to Figure 15, the bogey 130 is also arcuate in shape and has
two holes 132 for wheel mounting axle bolts, and two additional holes 133
forthe pins
127 used to connect the bogey to beams 120.
With reference to Figure 16, frame 140, like frame 140, comprises two
parallel,
spaced-apart rails 141 held in fixed relationship one to the other by means of
heel
and toe plates (not shown). Each rail includes a pair of slots 44 that
accommodate
movement of the shoulder bolts used to connect beams 120. This function is
best
illustrated in the schematical representation of Figure 17. The vertical
displacement
of the wheels in this embodiment is limited by contact between upper curved
surface
137 of bogey 130 with the lower curved surtace 147 of rail 141 as best shown
again
with reference to Figure 17.
Figures 10 to 12 show how the present suspension, including the
embodiments of both Figures 1 and 13, adapt to concave, flax and convex
skating
surfaces.
Skates fitted with the suspension of Figure 1 can include a conventional heel
brake. An alternative k>raking mechanism particularly adapted to the
embodiment of
Figure 13 is shown with reference to Figure 18. When the skater elevates the
toe of
the skate and weights the rear wheels, the two front wheels become elevated,
allowing the skater to manoeuver on the two rear wheels. By exerting more
pressure
on the rear wheels, a brake pad 180 mounted under the heel of the boot can
engage
the rearmost wheel. This action is reversed when the heel of the boot is
raised and
the toe is depressed. Thus, it may be feasible to have both toe and heel
brakes. A
further alternative for use with the embodiments of Figures 1 and 13 is shown
in
Figure 19. Specifically, bogey 130 is extended to include a levered arm 136
with a
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brake pad 150 situated to engage the skating surface when the skate is tilted
rearward.
The present suspension is readily adapted to speed skates or ski simulators.
For example, the wheel supporting legs of beams 20/120 can be elongated as
desired to locate the leading and trailing wheels well forward and well aft of
the boot.
Other advantages of the present suspension include its automatic adjustment
to wheels of different diameter. For example, some hockey players prefer that
the
two rear wheels have a larger diameter than the two forward wheels. The
present
suspension adjusts to the two sizes automatically. The suspension is also
adjustable
for skaters of different weight. Specifically, pins 27 and 28 can be
additionally
torqued for relatively heavy skaters and loosened for lighter skaters.
Tightening will
stiffen the suspension to improve its shock adsorbing characteristics for
larger skaters
and loosening will allow the suspension to flex more easily for lighter
skaters. Skaters
can therefore adjust the friction in the suspension until it suits their
preferences.
The above-described embodiments of the present invention are meant to be
illustrative of preferred embodiments and are not intended to limit the scope
of the
present invention. Various modifications, which would be readily apparent to
one
skilled in the art, are intended to be within the scope of the present
invention. The
only limitations to the scope of the present invention are set forth .in the
following
claims appended hereto.
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