Note: Descriptions are shown in the official language in which they were submitted.
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ROLLER ASSEMBLY FOR AN IN-LINE ROLLER SKATE
TECHNICAL FIELD
The invention relates to a roller assembly for an in-line roller skate.
BACKGROUND
Many roller assemblies for in-line roller skates have been introduced to this
day. Typically, the roller assemblies have in common a plurality of equal size
weight bearing roller wheels fastened pivotally with a roller frame such that
the roller wheels are arranged linearly and glide in the same plane upon a
surface. The roller frame is generally fabricated using an extrusion process,
the material being a metal, such as steel or aluminum, or a composite
material. The extrusion is machined so as to create two side walls that extend
lengthwise of the frame and that are spaced apart transversely of the frame.
The side walls are bridged by mounting brackets that are spaced lengthwise
of the frame to provide for mounting of the frame to the heel and sole regions
of a skating boot or shoe. It is further known to provide a transverse slot in
one of these mounting brackets so that a fastening means which is used to
fasten the roller frame to the boot or shoe may pass through and provide a
limited degree of transverse adjustment of the roller frame on the boot or
shoe
at that mounting bracket. It is also known to mount the roller wheels,
typically
made of polyurethane, between the side walls of the frame by means of axles
that fit in aligned through-holes in the side walls.
Maneuverability and stability are two important characteristics of in-line
roller
skates. The longer the roller wheel base of the roller assembly (e.g. the
distance from front to rear roller wheels), the more stable the roller skate
is
but the less maneuverable it becomes. Conversely, the shorter the roller
wheel base of the roller assembly, the more maneuverable the roller skate is
but the less stable it becomes. The stability is due to the fact that the
longer
the roller wheel base is, the farther the roller wheels extend beyond the toes
and heel of the skating boot or shoe having for effect to stop the user from
tumbling forwards or backwards when the weight of the user is biased forward
or backward, respectively. On the other hand, the longer roller wheel base
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hinders maneuverability by increasing the turning radius of the in-line roller
skate.
Conversely, the maneuverability is due to the fact that the shorter the roller
wheel
base is, the smaller the in-line roller skate's turning radius is. On the
other hand,
the shorter roller wheel base makes it easier for the user to tumble forwards
or
backwards when his weight is biased forward or backward, respectively.
Thus, an increase in either of the two characteristics entails a reduction in
the other
characteristic.
SUMMARY
In accordance with the present invention, there is provided a roller assembly
of an
io in-line roller skate, said roller assembly comprising a roller frame, a
front roller
wheel, at least two middle roller wheels and a rear roller wheel fastened
pivotally
with said roller frame such that said front, middle and rear roller wheels are
arranged linearly, said front roller wheel being of a first size, said at
least two
middle roller wheels being of a same second size greater than said first size,
said
rear roller wheel being of a third size greater than said second size, wherein
said
rear and middle roller wheels are positioned to be engageable to a same planar
surface while the front roller wheel is located at a given distance from the
planar
surface.
In accordance with another aspect of the present invention, there is provided
a
2o roller assembly of an in-line roller skate, said roller assembly comprising
a roller
frame, a front roller wheel, at least two middle roller wheels and a rear
roller wheel
pivotally and linearly received in the roller frame, each of the roller wheels
being
received in a predetermined, unchangeable position in the roller frame, said
front
roller wheel having a first radius, said at least two middle roller wheels
having a
same second radius greater than the first radius, and said rear roller wheel
having a
third radius greater than the second radius.
BRIEF DESCRIPTION OF THE FIGURES
An embodiment of the invention will now be described by way of example only
with reference to the accompanying drawings, in which:
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FIG. 1 is a partial sectional view of a roller assembly for an in-line roller
skate in
accordance with a particular embodiment of the present invention.
FIG. 2 is a side elevational view of the roller assembly of FIG. 1 in a first
operative
mode.
FIG. 3 is a side elevational view of the roller assembly of FIG. 1 in a second
operative mode.
DETAILED DESCRIPTION
Referring to FIG. 1, there is shown a partial sectional view of a roller
assembly 10
for an in-line roller skate in accordance with a particular embodiment of the
present invention. The roller assembly 10, habilitated for receiving an
associated
footwear 30 such as a skating boot or shoe, comprises a roller frame 9 to
which are
pivotally fastened roller wheels 2, 4, 6, 8 about rotation axis 12, 14, 16,
18,
respectively, through for example, a pin disposed in a slot. In the
illustrated
embodiment the roller assembly 10 has four roller wheels 2, 4, 6, 8 but it is
to be
1s understood that alternative embodiments may have a different number of
roller
wheels, for example a roller assembly for children in-line roller skates may
have
three roller wheels instead of four.
The roller wheels 2, 4, 6 and 8 are of radiuses 13, 15, 17 and 19,
respectively. In
the particular embodiment, the front roller wheel radius 13 has the smallest
value,
the rear roller wheel radius 19 has the biggest value and the two middle
roller
wheel radiuses 15, 17 have values in between that of the front roller wheel
radius
13 and of the rear roller wheel radius 19. In accordance with a particular
embodiment, the middle roller wheel radiuses 15, 17 are approximately equal.
For
example, the front roller wheel 2 may have a radius
4
13 of 36 mm, the middle roller wheels 4, 6 may have a radiuses 15, 17 of 38
mm and the rear roller wheel 8 may have a radius 19 of 40 mm. It should be
noted that these values are described by way of example only, other
combinations of roller wheel radiuses may be possible.
When the roller assembly 10 is in a resting position, the front roller wheel 2
and middle roller wheels 4, 6 have rotation axis 12, 14, 16, respectively,
which
are positioned generally equidistantly from surface 1, in other words
distances
22, 24, 26 are approximately equal. However, the rear roller wheel's 8
rotation axis 18 is positioned at a greater distance from surface 1. More
specifically distance 28 is greater than distances 22, 24 and 26. The
difference between distance 28 and distances 22, 24 and 26 is proportional to
the difference in radius between the middle roller wheels 4, 6 and the rear
roller wheel 8. In the earlier example, where the middle roller wheels 4, 6
have radiuses 15, 17 of 38 mm and the rear roller wheel 8 a radius 19 of 40
mm, this translates in distance 28 being 2 mm greater than distances 22, 24
and 26. This insures that when the assembly 10 is in a resting position, that
is
the middle roller wheels 4, 6 and the rear roller wheel 8 are all resting on
surface 1, the roller frame 9 remains parallel to surface 1.
The front roller wheel 2 having a radius 13 which is smaller than the radiuses
15, 17 of the middle roller wheels 4, 6, while having a distance 22 equal to
distances 24 and 26, entails that, when in a resting position, the front
roller
wheel 2 is not in contact with surface 1. Thus, in a resting position, there
is a
gap 11 between the front roller wheel 2 edge and surface 1. The size of front
gap 11 is equal to the difference between the front roller wheel 2 radius 13
and distance 22, which is the middle roller wheels 4, 6 radiuses 15, 17. To
continue with the earlier example where the front roller wheel 2 has a radius
13 of 36 mm and the middle roller wheels 4, 6 have a radiuses 15, 17 of 38
mm, this translates in a front gap 11 of 2 mm.
In use, the variation in the sizes and positioning of the roller wheels 2, 4,
6
and 8, as described above, creates a rocker function that responds to the
weight distribution of the user of the roller assembly 10. This rocker
function
has for effect to put the roller assembly 10 in either of two positions.
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In a first position, such as shown in FIG. 2, the middle roller wheels 4, 6
and
the rear roller wheel 8 are all in contact with surface 1 while front roller
wheel
2 has gap 11 between its bottom edge and surface 1 such that only three of
the four roller wheels are in contact with surface 1. This results in a
shortening of the roller wheel base, which provides better maneuverability by
allowing for a shorter turning radius while still providing similar stability
as
provided by four roller wheels since when the weight of the user is biased
towards the rear, no weight is applied to the front roller wheel 2 and the
rear
roller wheel 8 is positioned beyond the heel of the user. Furthermore, the
larger size of the rear roller wheel 8 allows the in-lune roller skate to
carry
more speed when the user is turning an thus is in full acceleration. This
first
position is achieved for example, when the user of the roller assembly 10 is
standing still, is in the process of turning or has his weight on his heels.
In a second position, such as shown in FIG. 3, the front roller wheel 2 and
the
middle roller wheels 4, 6 are all in contact with surface 1 while rear roller
wheel 8 has gap 21 between its bottom edge and surface 1 such that only
three of the four roller wheels are in contact with surface 1. As with the
first
position, this shortening of the roller wheel base provides better
maneuverability while still providing similar stability as provided by four
roller
wheels since when the weight of the user is biased towards the front, no
weight is applied to the rear roller wheel 8 and the front roller wheel 2
extends
beyond the toes of the user. This second position is achieved for example,
when the user of the roller assembly 10 is moving forward in a generally
straight direction.
It should be noted that in the case where the roller assembly 10 comprises
four roller wheels 2, 4, 6 and 8, the front and two middle roller wheels 2, 4
and
6 are simultaneously in contact with surface 1 when the user's weight is
biased forward, even though the two middle roller wheels 4 and 6 are of
similar sized. This is the result of the compressive nature of the material
used
in the fabrication of typical roller wheels, such as polyurethane, that allows
the
middle roller wheel 4 to slightly compress such that front roller wheel 2 and
the middle roller wheels 4 and 6 are all simultaneously in contact with
surface
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1. As know in the art, the compression of typical roller wheels varies
according to the durometer (hardness) of the material used. Thus, depending
on the sizes of the front and two middle roiler wheels 2, 4 and 6, an
appropriate roller wheel material durometer may be selected.
Although the present invention has been described by way of particular
embodiments and examples thereof, it should be noted that it will be apparent
to persons skilled in the art that modifications may be applied to the present
particular embodiment without departing from the scope of the present
invention.
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