Note: Descriptions are shown in the official language in which they were submitted.
CA 02299008 2000-02-21
BOARD WITH ROLLERS FOR DESCENDING HILLS
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a board with rollers which can be used on hills with
soft or
grassy terrain.
2. Description of the Related Art
. Snowboarding has become increasingly popular and is quickly emerging as a
full-
fledged competitive winter sport with acrobatic exhibitions and artistic
performances.
Accordingly, snowboards now account for a significant portion of traffic on
the slopes at ski
resorts. As the sport evolves however, efforts have been directed towards
expanding its field
of practice, which until now has been substantially limited to snow covered
slopes. Snowboard
athletes and enthusiasts require warm weather training aids to allow them the
opportunity to
practice for their sport all year around. Thus, a need has appeared for dry
land snowboards that
can faithfully reproduce the sensation of riding on a snowboard while being
used on terrain with
an irregular topography, not unlike a snowboarding slope.
While skateboards allow riding on dry land, they are unable to imitate the
turning
characteristics of snowboards. As is well understood, snowboards are one track
devices that
turn primarily by "edging". When a rider leans his weight towards the intended
direction of
travel, the snowboard leans onto its edge and turns an arc equivalent to the
board's edge. This
is made possible by the presence of sidecuts in the board and flex in the
board design. In
comparison, skateboards are two track devices that turn by steering. While
both devices can
"carve", that is, turn as a result of the rider leaning towards the intended
direction of travel, they
do so through a different mechanism. As a result, two track devices do not
make effective
training aids for snowboarders.
U.S. Pat. No. 5,855,385, issued January 5, 1999 to Hambsch, describes a
wheeled
board device that has a platform with concave sides. Primary wheels are
located along a central
longitudinal axis of the platform and outrigger wheels are located along the
concave sides so
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that the apparatus is a capable of turning as a two track device in a learner
mode and is also
capable of turning as a one track device in a more advanced expert mode. While
perhaps
functional on a paved surface, this wheeled board device would be undermined
by dirt and grass
if it were used on rough hill terrain.
SUMMARY OF THE INVENTION
This invention seeks to provide roller boards which can simulate the turning
characteristics of a snowboard.
The present invention provides a rollerboard apparatus with a platform and a
plurality
of rollers. The rollers are disposed below the platform and extend
transversely of the platform.
The rollers are arranged one behind the other along the length of the platform
and have lengths
which progressively decrease from each end of the platform toward the centre
of the platform.
The provision of rollers with decreasing lengths towards the centre of the
platform imitates the
function of sidecuts in a snowboard and enables the rollerboard apparatus to
turn by "edging".
When the rider leans towards one side, the edge of the rollers provide a rough
arc through
which the turn is effected. The use of elongated rollers increases the amount
of roller surface
engaging the ground thereby reducing the possibility of rollers digging into
soft hill terrain.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be further understood from the following
description with
references to the drawings in which
FIG. 1 is a perspective view of a board with rollers for descending hills in
accordance
with an embodiment of the present invention;
FIG. 2 is a side elevation view of the board shown in FIG. 1 with the right
hand
carriage shown in section;
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FIG. 3 is a bottom view of the board shown in FIG. 1;
FIG. 3A is an enlarged bottom view of a portion of the board indicated at 3A
in FIG.
3;
FIG. 4 is a top view of the board shown in FIG. 1;
FIG. 5 is a front elevation view looking in the direction of arrows 5 - 5 of
FIG. 2;
FIG. 6 is an enlarged fragmentary exploded view of a portion of the board of
FIG. 1;
and
FIG. 7 is a bottom view of the board in another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Refernng to FIG. 1, a board with rollers for descending hills 110 comprises an
elongated platform 112 ; roller assemblies 130 and 132 ; and a pair of
bindings 134a and 134b
(collectively bindings 134).
The bindings 134 are mounted to a top surface 114 of platform 112 and
positioned
centrally over roller assemblies 130 and 132, so as the weight of the rider is
evenly distributed
across the roller assemblies. In the preferred embodiment, the bindings 134
are rigidly mounted
one behind the other and oriented transversely to a longitudinal centre line
115 of platform 112.
Alternatively, the bindings 134 may be mounted as desired on platform 112 in
fore and aft or
staggered orientations. As well, the bindings 134 may be free to pivot on top
surface 114.
Preferably, the bindings 134 are snowboard type bindings as shown in FIG. 1.
As shown in FIG. 4, the platform 112 has a length L and a maximum width W. The
length L of the platform is preferably at least four times the maximum width
W. In a preferred
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embodiment, the platform 112 has a maximum width W of 11.25 in. and a length L
of 48 in.,
but these dimensions may be varied to adjust to the various body types
(height, weight) of
riders. Preferably, the length L and maximum width W of platform 112 closely
resemble those
of a snowboard and are much larger than those of a conventional skateboard
deck, which
typically measures in the range of 7.5 in. to 8.5 in. in width and 31 in. to
34 in. in length. As
will be explained later, this additional size enhances the stability of the
board and gives the
rider greater control as the board with rollers 110 descends a hill.
The platform 112 has roughly the same flexural and torsional characteristics
as a
snowboard. The platform 112 may be constructed of any conventional materials
including, but
not limited to: wood, fibreglass, mold injected or spun plastic and metal,
such as aluminum or
a composite thereof. If wood is chosen, laminates may be particularly
preferred to enhance
strength and durability. Similarly, preferred fibreglass constructs includes
cores of disparate
materials (not illustrated), such as balsa, in order to enhance rigidity and
support.
As is shown in FIG. 3, the portion of the platform between the front 124 end
and the
centre 126 of the platform and the portion of the platform between the rear
128 end and the
centre 126 of the platform, are identically shaped and preferably taper
inwardly towards the
centre 126 of the platform, much like in a snowboard. However, it will be
appreciated that the
shape of the platform could be altered to allow for design or stylistic
effects.
Roller assemblies 130 and 132 are positioned along longitudinal centre line
115 of the
platform, extending from the front 124 and rear 128 ends of the platform,
respectively. The
roller assemblies 130 and 132 are preferably transversely spaced as far apart
from each other
as the length L of the platform will permit so as to create a longer wheel
base. In the preferred
embodiment, the length of the wheel base as measured from an axle 160 of
roller assembly 130
to an axle 166 of roller assembly 132 is 37.5 in. In comparison, the length of
the wheel base on
a conventional skateboard is 20 in. A longer wheel base increases stability
and makes for an
easier ride down the hill in the same manner as increasing the length of the
base of a snowboard
contributes to its overall stability.
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Referring to both FIGS. 3 and 5, the shoulder portions 118 and 120 of the
platform
extend downwardly from the bottom surface 116. In the preferred embodiment,
the shoulder
portions 118 and 120 run along the bottom surface 116 parallel to the inwardly
tapered sides
122 of the platform. The roller assembly 130 comprises a pair of spaced L-
shaped mounting
brackets 138 and 140 which incline towards each other towards the centre 126
of the platform.
The mounting brackets 138 and 140 are fixed to a mounting surface 136 of
shoulder portions
118 and 120 (which mounting surface is parallel to the bottom surface 116 of
the platform) by
a number of screws or other suitable fasteners. It will be appreciated that
although the preferred
embodiment shown in the drawings takes the form of a platform having shoulder
portions to
which are attached mounting brackets, the manner by which the roller
assemblies are mounted
to the platform could differ in other embodiments of the invention. For
example, the platform
could be constructed without shoulder portions, in which case the mounting
brackets (modified
to provide a suitable stand-off between platform and the rollers) could be
directly fastened to
the bottom surface of the platform. Alternatively, a C-shaped mounting bracket
extending
laterally across the platform could be used in place of each pair of like L-
shaped mounting
brackets. In another variation, the brackets could be moulded into the
platform such that the
board and mounting brackets form a single unit.
Referring to FIG. 6, the mounting brackets 138 and 140 have slots 142. When
the
mounting brackets 138 and 140 are secured to the platform, corresponding slots
of each bracket
are transversely aligned. The roller assembly 130 thus has pairs of directly
opposed slots 142.
In the preferred embodiment, each slot 142 receives a roller suspension 144.
The roller
suspension 144 preferably comprises a sliding block 146, a helical coil spring
148 and a
neoprene pad 156 assembled to form what is known as a captive sliding block
arrangement. The
sliding block 146 has a counterbore 150 to locate the helical spring 148. The
other end of
helical spring 148 is similarly located in a counterbore 154 provided within
the mounting
brackets 138 and 140. The neoprene pad 156 is located at the bottom of slot
142 and supports
the sliding block 146. The sliding block 146 has channels 152a and 152b which
slidingly
engage the walls of slot 142. As seen in FIGS. 3A and 6, the sliding block 146
supports the end
of a roller axle 160 of a roller 161a. The bore 174 within sliding block 146
is oriented so that
when the sliding block 146 is received within slot 142, the sliding block
receives roller axle 160
perpendicularly.
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The roller suspension 144 serves to absorb some of the shock that is
encountered by the
rider when the board is used to descend hills that have rocky and uneven
terrain. In this way,
the roller suspension 144 allows for improved steering and provides the rider
with a smoother
ride. In addition, the roller suspension 144 reduces the stress on the
platform. While roller
suspensions are preferred for these reasons, they are not necessary. .
Referring to FIG. 3, in the preferred embodiment, the roller assembly 130 has
three
cylindrical rollers 161a, 161b and 161c which are rotatably mounted to roller
axles 160, 162
and 164, respectively. Bearings 172 (shown in FIG. 6) embedded within the
rollers permit the
rollers to rotate about the roller axles. The roller axles 160, 162 and 164
are preferably equally
spaced from each other and are disposed transversely between the mounting
brackets 138 and
140. The opposite ends of roller axles 160, 162 and 164 are received in and
supported by roller
suspensions 144. Spacer bushings 168 disposed on the roller axles between the
rollers and the
roller suspensions 144 prevent the rollers from coming into contact with the
mounting brackets
138 and 140. Crown nuts 170 (shown in FIG. 6) thread to the axles to secure
the roller axles
to the roller suspensions 144.
In the preferred embodiment, rollers 161a, 161b, and 161c substantially span
the width
of the platform 112. The use of elongated rollers increases the amount of
roller surface
engaging the ground thereby reducing the possibility of the rollers digging
into soft hill terrain,
for example, dirt or grass. In addition, the use of elongated rollers in the
roller assembly
provides an advantage over the narrower wheels employed in conventional
skateboards in that
there are fewer places for grass or other vegetation to become stuck in the
roller assembly and
slow down the board with rollers 110.
As shown in FIG. 3, the lengths of rollers 161a,161b and 161c progressively
decrease
towards the centre 126 of the platform so that the outside roller 161a is
longer than the middle
roller 161b which is longer than the inner roller 161c located nearest to the
centre 126 of the
platform.
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Roller assembly 132 is a mirror image of roller assembly 130; thus, it also
comprises
a series of rollers 167a, 167b and 167c with the outside roller being the
longest roller and the
narrowest roller being most proximate the centre 126 of the platform.
The tapering of the roller lengths in this fashion facilitates changing
directions and
simulates the turning characteristics of snowboarding. In the board with
rollers 110, the
provision of rollers 161a, 161b, 161c, 167a, 167b and 167c with decreasing
lengths towards
the centre of the platform imitate the function of sidecuts in a snowboard.
When the rider leans
towards one side, the edge of rollers 161a, 161b,161c, 167a, 167b and 167c
provide a rough
arc through which the turn is effected. Thus, the board with rollers 110 turn
by "edging" much
like the snowboard. As with the snowboard, the rider of the board with rollers
110 may vary
the distribution of his weight along the board 112 to effect a more or less
severe turn. The
ability to carve in the board with rollers is further enhanced by the roller
suspension 144 as well
as the flex in the board 112 itself. The turning characteristics of the board
with rollers 110 are
I S also affected by the degree with which the lengths of the rollers are
tapered inwardly. It will be
appreciated that a more drastic tapering of the roller lengths will of
necessity provide the board
with rollers 110 with a smaller turning radius and consequently, a quicker
responsiveness.
However, excessive tapering will adversely affect the stability of the board
with rollers 110 and
effectively, provides less roller surface to engage the ground. It is
preferred that the tapering of
the roller lengths parallels the tapering of the platform such that an
experienced rider can
ascertain the quick responsiveness or "turnability" of the board with rollers
110 by generally
looking at the inwardly tapered sides 122 of platform 112, much in the same
way a snowboarder
would appreciate the turnability of his snowboard by glancing at the sidecuts
of the board. In
a preferred embodiment, the lengths of the rollers are progressively tapered
with the length of
outer roller 161a being 7.25 in., the length of middle roller 161b being 6.83
in., and the length
of inner roller 161c being 6.5 in. In a preferred embodiment, the minimum
length for the inner
roller located nearest to the centre 126 of the platform is 6 in.
In a preferred embodiment, the rollers 161a,161,161c,167a,167b and 167c each
have
an outer diameter of 3.5 inches. This outer diameter has been found to be
sufficiently large so
as to avoid problems with grass catching on the rollers and slowing down the
board as it
descends a grassy hill. However, preferably the outer diameter is generally
greater than 2 in.
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The rollers 161a, 161b, 161c, 167a, 167b and 167c may be constructed from
rubber or
a synthetic hard resin such as a hard plastic. Alternatively, the rollers may
also be manufactured
with foam cores and with fibreglass reinforced plastic, polypropylene,
polyurethane, ABS
plastic tubing or rubber exteriors. In another embodiment, the rollers could
be cylindrical low
pressure pneumatic roller tires made of rubber or other suitable materials. In
this embodiment,
the roller assemblies would be outfitted with no roller suspensions as the
pneumatic roller tires
themselves would act to absorb shock. Furthermore, where pneumatic roller
tires would be used
instead of hard plastic rollers, these roller tires would have tread at their
edges so as to facilitate
turning.
Referring to FIG. 5, the board 110 is preferably provided with a clearance of
at least
0.25 in. between rollers 161a,161b,161c,167a,167b and 167c and the bottom
surface 116 of
the platform. This clearance provides a safeguard against a stone or other
debris lodging
between the rollers and the platform and freezing the rotation of any of the
rollers during the
descent.
It will be appreciated that although the preferred embodiment shown in the
drawings
takes the form of two roller assemblies, each having three elongated rollers,
the invention could
take a different form. For example, the middle roller could be removed from
each roller
assembly. In this variation, each roller assembly would thus have an outer
roller located
proximate an end of the platform and an inner roller located more proximate to
the centre of
the platform. The distance as between these rollers could remain the same as
for the
corresponding rollers of the three roller embodiment of the invention. It will
be appreciated that
removing the middle roller would make the board with rollers capable of
achieving greater
speeds as a result of a lightened roller assembly and a reduction in rolling
friction. However,
less stability would be afforded with the two roller embodiment as a result of
the missing roller.
Alternatively, if stability were a primary consideration, as is the case for
novice riders,
additional rollers could be added to the roller assembly. In a further
variation, each roller could
be build up from wheels 750 mounted side-by-side on each roller axle, as shown
in FIG. 7. The
adjacent wheels could be independently rotatable to accommodate for the
tendency for opposite
ends of a roller to travel at different speeds when rounding curves.
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Although the present invention has been illustrated with reference to certain
preferred
embodiments, it will be appreciated that the present invention is not limited
to the specifics set
forth therein. Those skilled in the art will appreciate numerous modifications
and variations
within the spirit and the scope of the present invention, and all such
variations and
modifications are intended to be covered by the present invention, which is
defined by the
following claims.
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