Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02330272 2001-01-05
SUSPENSION SYSTEM FOR INLINE SKATES
Field of the Invention
The present invention generally relates to a suspension system for inline
skates, and more specifically, to a suspension system that incorporates a
flexible
beam to absorb shock and thereby increase the comfort to those skating over
rough terrain.
Background of the Invention
Inline skating has become a popular pastime, providing both a relaxing
outdoor activity and exercise. Compared to earlier skates having two axles on
which pairs of opposed wheels were mounted, inline skates used today are much
more comfortable and safe. The wheels of inline skates are designed for
outdoor
usage and readily roll over surfaces that are not very smooth or free of
debris.
Early skates either had no suspension system, or at best, a very primitive
suspension system. Modern inline skates employ wheels made of an elastomeric
material that helps to absorb shock, but is not sufficient to absorb the shock
of
rough terrain, where sidewalk expansion strips, frost heaved sections, and
pebbles
can produce rather significant shocks to the skater's feet.
To help absorb such shock and enhance the performance and comfort of
inline skates, certain inline skates have been designed with more
sophisticated
suspension systems. Prior suspension systems have included coil springs,
elastomeric blocks, leaf springs, and hydraulic pistons. While such suspension
systems can indeed enhance the performance of inline skates, they tend to
interfere with the control exercised by the skater, don't provide sufficient
shock
absorption, or are too complex and expensive. Prior art suspension systems
that
include springs primarily permit vertical deflection of the wheels and are not
readily tuned to accommodate skaters of differing weight. Furthermore, it
would
be desirable to employ a suspension system that allows for other modes of
deflection other than in the vertical plane. From a manufacturing and cost
consideration, it would be desirable to develop an effective suspension system
for
inline skates that is relatively simple, contains few parts, and is easy to
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manufacture. From the viewpoint of the user of inline skates, such inline
skates
should also be durable and should not interfere with the skating experience.
Preferably, the suspension system should improve the comfort and the control
of
the skater, particularly while cornering. In addition, the suspension system
should
enable the skater to accelerate with greater force by unleashing stored energy
as
the skater pushes off from a mark.
Summary of the Invention
The present invention provides a simple, yet effective suspension system
that reduces the discomfort caused by inline skating over an uneven or rough
surface. Additionally, the resiliency of the suspension system provides better
control when cornering and aids the skater in pushing off and accelerating. As
the
skater exerts a downward force on the skate to move forward, the suspension
system is deflected in response to the force of the skater's effort. When the
skater
releases the downward pressure, the suspension system returns the stored
energy
by providing additional thrust to move the skater forward, as the suspension
system returns to its undeflected position.
In accord with the present invention, a suspension system for an inline
skate is defined that includes a bracket adapted to attach to a boot, which
receives
a user's foot. A flex beam having a center and opposite ends extending
longitudinally from the center is provided, and the center of the flex beam is
connected to the bracket and supported thereby. Each end of the flex beam is
adapted to connect with and support a wheel on an axle, so that the wheel can
rotate. The ends of the flex beam deflect to absorb shock when a wheel
supported
by an end of the flex beam rolls over a bump.
Preferably, the system includes another flex beam like the one defined
above. Again, each end of the other flex beam is adapted to connect with and
support a wheel on an axle that enables the wheel to rotate. These two flex
beams
are disposed along opposite sides of the bracket, and the end of each flex
beam
deflects to absorb shock when a wheel supported by that end rolls over a bump.
In one preferred form of the invention, the flex beam is fabricated from a
metal having predefined elastomeric properties. It is also preferable to taper
the
flex beam, so that it is thinner at each end to achieve a specified deflection
for a
defined force. The flex beam is also preferably removably coupled to the
bracket
using a fastener.
The ends of the flex beam deflect vertically and also may deflect laterally
to absorb the shock of a wheel rolling over a bump. In addition, the flex beam
deflects about its longitudinal axis when absorbing shock.
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The bracket preferably has a side that depends downwardly, so that the
flex beam is attached to the side of the bracket, along a lower edge. In one
preferred form, the bracket is generally shaped like an inverted "U," with
opposite
sides. The two flex beams are then mounted to the opposite sides of the
bracket,
along the lower edges. Each side of the bracket includes a front edge and a
rear
edge that are angled towards each other along the bottom of the bracket. The
angled edges provide clearance for deflection of the wheels. In addition, the
flex
beam includes a tab at each end in which an orifice adapted to accept an axle
for
supporting a wheel is provided.
A further aspect of the present invention is directed to a method for
reducing shock and vibration transmitted to a skater when a wheel of an inline
skate rolls over a bump. The method includes steps that are generally
consistent
with the elements of the system described above.
Brief Description of the Drawing Figures
The foregoing aspects and many of the attendant advantages of this
invention will* become more readily appreciated as the same becomes better
understood by reference to the following detailed description, when taken in
conjunction with the accompanying drawings, wherein:
FIGURE 1 is an isometric view of a preferred embodiment of the
suspension system in accord with the present invention, shown in relation to
an
inline skate boot (depicted in phantom view);
FIGURE 2 is a partially exploded isometric view of the prefirrred
embodiment of FIGURE 1;
FIGURE 3 is a fully exploded isometric view illustrating more details of
the suspension system of the embodiment of FIGURES 1 and 2;
FIGURE 4 is a side elevational view of the suspension system and wheels,
in relation to a boot shown in phantom view;
FIGURE 5 is a bottom plan view of the suspension system and wheels;
FIGURE 6 is a left side elevational view of the suspension system and a
boot (depicted in phantom view), illustrating the vertical deflection of a
skate
wheel and its associated flex beam;
FIGURE 7 is a front elevational view of the suspension system, showing a
front wheel and its associated flex beam in an undeflected position, and
FIGURE 8 is a front elevational view of the suspension system, showing a
wheel and its associated flex beam deflected vertically, and rotationally
about a
longitudinal axis of the flex beam.
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Description of the Preferred Embodiment
FIGURES 1 through 5 illustrate a preferred embodiment of the present
invention. The following discussion includes the terms left, right, front,
rear and
forward, which are consistent with the terms a person wearing the inline skate
boot as in FIGURE 1 would use to describe the inline skate and its
orientation.
Thus, "left" refers to the side to the left of the skater, "right" refers to
the side to
the right of the skater, "front" refers to the end of the skate leading in the
direction
in which the skater normally travels "forward" (as indicated by the large
arrow in
the drawings), and "rear" refers to the opposite end or direction.
In FIGURE 1, the disposition of the suspension system is shown relative to
a typical inline skate boot 10. A top surface 11 of a mounting bracket 12
includes
orifices 13 that accept fasteners (not shown) for use in securing the mounting
bracket to the sole of boot 10. The type of fastener used to affix boot 10 to
mounting bracket 12 is not a critical feature of the present invention. In the
preferred embodiment, the fasteners employed will likely permanently affix
boot 10 to mounting bracket 12. Rivets, adhesive, molded constructs, or other
permanent fastening means may be used for this purpose. It is also envisioned
that removable fasteners such as screws, threaded bolts, or pins and clips can
be
used to connect boot 10 to mounting bracket 12. Use of removable fasteners for
connecting boot 10 and mounting bracket 12 would allow either component to be
replaced if desired.
Mounting bracket 12 is generally elongate, and when viewed from either
end, appears to have an inverted "U" shape. The downwardly depending sides of
the mounting bracket include a left side 15L, as shown in FIGURE 1, and a
right
side 15R, as shown in FIGURE 4. When viewed from the side as in FIGURE 4,
sides 15L and 15R are not congruent, but instead, may be described as being
"complementarily asymmetrical," since each side is designed to support
different
pairs of wheels 16a/16c, and 16b/16d, respectively.
Extending outwardly from the lower edge of side 15L is a beam
bracket 25L. A similar beam bracket 25R extends outwardly from the lower edge
of side 15R, as shown in FIGURE 5. Beam bracket 25L is connected to a flex
beam 14L, as shown in FIGURES 1-3, and beam bracket 25R is similarly
connected to a flex beam 14R, using threaded fasteners 26, which extend
through
orifices 22 (shown in FIGURES 2-3) in the beam brackets and are threaded into
threaded orifices 24 formed in the flex beams. Alternatively, other types of
fasteners, including removable or permanent fasteners, such as rivets (not
shown),
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can be readily used to couple the beam brackets to the flex beams, as will be
appreciated by one of ordinary skill in the art.
Referring once more to FIGURE 1, it will be noted that flex beam 14L
comprises two tapered areas 18 in which the thickness of the flex beam changes
(flex beam 14R includes identically tapered areas, as will be apparent in
FIGURE 3). Flex beam 14L is thickest in its center, where the flex beam is
attached to beam bracket 25L. Moving both to the front and to the rear from
the
center of flex beam 14L, the thickness of flex beam 14L is gradually reduced
along the length of tapered areas 18. Tapered areas 18 control the resiliency
or
flexure of flex beams 14L and 14R. Preferably, the flex beams are fabricated
from a heat-treated stainless steel, but it is also contemplated that they may
be
made of fiber reinforced plastic or other suitable materials having the
required
strength and elasticity. The thickness of the flex beams and the degree of the
taper in tapered areas 18 are selected to provide a desired amount of
resiliency to
the suspension system so that the flex beams deflect by a desired amount for a
specific force. Tapering the thickness of the flex beams also ensures that
more of
the deflection of the flex beams occurs closer to the ends of the flex beams
rather
than at the center where the flex beams are attached to beam brackets 25L
and 25R, respectively.
While flex beams 14L and 14R include tapered areas 18 in this preferred
embodiment, it is envisioned that flex beams without tapered areas can
alternatively be used. The suspension characteristics (the "softness" or
"firmness"
of the suspension) can be controlled by varying either the thickness of the
flex
beams or the degree and longitudinal extent of tapered areas 18. It is also
contemplated that the flex beams may be configured to have an arcuate shape
(i.e.,
with a concave side of the arcuate shaped flex beams facing downwardly) to
provide yet another parameter for controlling the resiliency of the suspension
system. It is also contemplated that inline skates will be provided with
suspension
systems that are appropriate for use by skaters of differing weight and skill
level.
A heavier skater will likely prefer a suspension system that is stiffer and
deflects
less for a given force than a lighter weight skater. In addition, a skater who
is
more experienced may also prefer a suspension system that is stiffer.
Adjacent to the thinnest section of each tapered area 18, flex beams 14L
and 14R include tabs 20, which extend downwardly from the horizontal surface
of
the flex beams. A particularly important feature of the preferred embodiment
of
the invention is the manner in which tabs 20 of flex beams 14L and 14R are
connected to the plurality of wheels 16a-16d of the inline skate. In the
preferred
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embodiment, the inline skate has four wheels 16a-16d, arranged sequentially in
a
line from the front to the rear of the mounting bracket, as clearly shown in
FIGURES 1-4 and FIGURE 6. Each wheel is connected to one tab 20 of either
flex beam 14R or flex beam 14L. Furthermore, as shown in FIGURE 3,
wheels 16a/16c are attached to tabs 20 at opposite ends of flex beam 14L and
wheels 16b/16d are attached to tabs 20 at opposite ends of flex beam 14R.
FIGURE 2 shows the preferred embodiment of the inline skate suspension
system seen from the same orientation as FIGURE 1, but with boot 10 removed
and mounting bracket 12 spaced apart from the flex beams, so that both flex
beam 14L and flex beam 14R can be seen. From this view, it can be clearly seen
that each wheel is attached to a different tab 20 of either flex beam 14R or
14L,
such that adjacent wheels are not connected to the same flex beam.
While not shown, it is envisioned that mounting bracket 12 and flex
beams 14L and 14R may be formed as an integral unit instead of as separate
pieces. Such an integral unit would preferably comprise a high impact fiber
reinforced polymer, formed by injection molding or other suitable process. The
fiber reinforcement should ensure that the resulting integrally formed flex
beams
are of sufficient strength and resiliency. The use of such an integral
structure is
expected to reduce manufacturing costs as well as simplifying the
production/assembly process.
FIGURE 3 clearly shows how mounting bracket 12, flex beams 14L and
14R, and wheels 16a-16d are connected to tabs 20, at the ends of flex beams
14L
and 14R. Axles 30 pass through tabs 20, then through ball or needle bearings
32,
which are disposed within the center of wheels 16a-16d and are held in place
by
axle retainers 34. The specific bearings 32 employed is not a critical feature
of
this invention, since it is contemplated that conventional high quality inline
skate
wheel and bearing assemblies will be used. Those of ordinary skill in the art
will
readily understand that a wide variety of wheel bearings and other types of
axle
assemblies may be connected to tabs 20.
In the preferred embodiment, axles 30 are fabricated of stainless steel.
Axle retainers 34 are threaded into the mating threaded orifices provided in
each
end of axles 30 and can be removed to facilitate maintenance or replacement of
wheels 16a-16d and bearings 32. While not preferred, it is contemplated that
axles 30 may be welded to tabs 20. Also, axle retainers 34 may be permanently
fastened to axles 30, precluding removal of the wheels from the axles. While
permanent connection of the wheel assemblies to flex beams 14L and 14R would
not allow for the replacement of the above-described components, this option
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would likely reduce manufacturing costs. However, it is preferable to employ
axles 30 and axle retainers 34 of the type and style used in conventional
inline
skates, since it is likely that experienced skaters will prefer to be able to
replace
these components when worn, with off-the-shelf replacements. Those of ordinary
skill in the art will readily understand that a variety of different axles 30
and axle
retainers 34 may be beneficially employed in the present invention.
FIGURE 4 is a side elevation view of the right-hand side of the preferred
embodiment of a roller skate in accord with the present invention. From this
perspective, it can clearly be seen that wheels 16a-16b are connected to tabs
20 of
flex beam 14 in such a fashion that alternating wheels are connected to
different
flex beams 14L or 14R. It also can clearly be seen that wheel 16b is connected
to
front tab 20 of right-hand side flex beam 14R. Similarly wheel 16d is
connected
to rear tab 20 of right-hand side flex beam 14R.
The perspective of FIGURE 4 also illustrates additional details of
mounting bracket 12. Note that an edge 12a of side 15R on mounting bracket 12
is angled away from wheel 16d sufficiently to provide substantial clearance
when
wheel 16d deflects under load. Similarly, an edge 12d of side 15L on mounting
bracket 12 is also angled to provide sufficient clearance for wheel 16a when
it is
deflected under load. Angled surfaces 12b and 12c (the latter being hidden
from
view and shown as a dashed line) reduce the mass and weight of mounting
bracket 12, and also provide clearance for the deflection of wheel 16b and
16c,
respectively. A web 35 (shown in dashed lines in this Figure because it is
hidden
from view) connects sides 15L and 15R, providing lateral support the sides and
generally strengthening the mounting bracket. FIGURE 5 shows web 35 more
clearly.
FIGURE 6 illustrates how flex beams 14L and 14R allow for the vertical
deflection of wheels 16a-16d to absorb shocks as the wheels roll over a
surface 36. In this view, wheel 16a is illustrated passing over a bump 38 on
surface 36. Forward tab 20 and forward tapered area 18 of flex beam 14L
support
wheel 16a, and are deflected upwardly a distance 40, to allow wheel 16a to
roll
over bump 38. Because wheels 16a-16d are independently suspended, the end of
the flex beams supporting each wheel will successively deflect upwardly as
that
wheel rolls over bump 38. Because of the shock absorbing deflection that
occurs
as each wheel encounters bump 38, the skater is NOT subjected to the series of
sharp jarring sensations experienced by a skater using conventional inline
skates
that do not include a suspension system. Instead, the present invention
absorbs
the shocks of expansion strips, uneven surfaces, pebbles, and other irregular
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surface features due to the deflections of the flex beams that support the
wheels on
each skate.
FIGURES 7 and 8 are to be treated as views of the present invention from
a head-on perspective that illustrates another of its features. This view
illustrates
wheel 16a traveling first over a smooth surface (FIGURE 7), and then over an
irregular surface (FIGURE 8) that causes deflection of the forward end of flex
beam 14L as wheel 16a, the front wheel, rolls over bump 38.
In FIGURE 7, wheel 16a is shown with the end of the flex beam deflected
only minimally, as would be the case when the wheel is rolling over a level
surface 36. FIGURE 8 shows how the present invention allows for both vertical
deflection of wheel 16a, as well as a deflection of wheel 16a about a
longitudinal
axis of flex beam 14L, when the wheel encounters bump 38. This bump causes
flex beam 14L and wheel 16a to deflect upwardly through a vertical distance 40
and to deflect laterally through a distance 42, as the wheel deflects around
the
longitudinal axis of flex beam 14L through an angle 44. The lateral and
angular
deflections of flex beam 14L and wheel 16a are somewhat exaggerated, to better
illustrate the deflections. While not shown, it should be understood that
wheels 16b-16d also deflect through a similar range of motion when the flex
beam
to which they are attached absorbs the shock as the wheels successively roll
over
bump 38. It has been found that this slight lateral and angular deflection
aids
control by the skater for much the same reason that a slight camber of
automobile
wheels is desirable to facilitate steering control of an automobile. When
cornering
or riding over bumps, it has been found that the suspension system in accord
with
the present invention enables the skater to remain in control and to enjoy a
level of
comfort that has generally not been noted in conventional inline skates
without a
suspension system.
Although the present invention has been described in connection with the
preferred form of practicing it, those of ordinary skill in the art will
understand
that many modifications can be made thereto within the scope of the claims
that
follow. Accordingly, it is not intended that the scope of the invention in any
way
be limited by the above description, but instead be determined entirely by
reference to the claims that follow.
