Wheel chair abstract
Front wheel support for a wheel chair, said front wheel support
comprising a curved tube for being attached to a frame member of
the wheel chair and a curved part. The curved part has a first portion
with a curvature being identical to the curvature of the curved
tube, and a cross section allowing the first portion of the curved
part to fit inside the curved tube. The curved part further comprises
a second portion with a wheel fork seat for mounting a front wheel
fork of said wheel chair.
Wheel chair claims
1. Front wheel support for a wheel chair, said front wheel support
comprising a curved tube for being attached to a frame member of
the wheel chair and a curved part, said curved part having a first
portion with a curvature being identical to the curvature of the
first curved tube, and a cross section allowing the first portion
of the curved part tube to fit inside the curved tube, and a second
portion with a wheel seat for mounting a front wheel fork of said
wheel chair.
2. The front wheel support of claim 1, wherein the first portion
of the curved part can be telescopically shifted inside the curved
tube, thus providing for an increased or decreased overlap between
the first portion of the curved part and the curved tube.
3. The front wheel support of claim 2, wherein due to the curvature
the inclination of the front wheel (22) is adjustable by increasing
or decreasing the overlap.
4. The front wheel support of claim 1, wherein a load path is provided
between the first portion of the curved part and the curved tube.
5. The front wheel support of claim 1, wherein a securing arrangement
is provided that allows the curved tube to be fixed with respect
to the curved part.
6. The front wheel support of claim 5, wherein the securing arrangement
comprises a sliding element with a threaded hole, a screw, and a
mounting piece.
7. The front wheel support of claim 5, wherein the first portion
of the curved part comprises a section that can be extended or expanded
in order to form a tight fit with respect to the curved part.
8. The front wheel support of claim 7, wherein the section can
be extended or expanded by means of a screw or a ring-shaped element.
9. The front wheel support of claim 1, wherein a securing arrangement
is provided that allows the curved tube to be fixed with respect
to the curved part, said securing arrangement comprising a nut and
a conical part sitting inside the curved tube.
10. Wheel chair comprising at least one front-wheel support of
one of the preceding claims.
Wheel chair description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority of European Patent Application
No. EP 03 004 757.5, filed Mar. 4, 2003, incorporated herein by
reference.
[0002] The present invention relates to a front-wheel support for
a wheel chair in accordance with claim 1, and wheel chair comprising
such a front-wheel support, in accordance with claim 10.
FIELD AND BACKGROUND OF THE INVENTION
[0003] Wheel chairs typically have one or two front wheels. These
front wheels are fixed to the frame of the wheel chair by means
of a front wheel support. The front wheel support is usually designed
to be operated in a upright position where the front wheel fork
turns about an axis that is essentially vertical with respect to
the ground.
[0004] When changing the geometry of the whole wheel chair, e.g.
when adjusting the seat heights and inclination, the frame of the
wheel chair is tilted with respect to the ground. This leads to
a situation where the front wheel support is not longer in an correct
upright position. Due to this, the front wheel cannot move and turn
as freely as intended. This means that after having modified the
wheel chair's geometry, one usually has to adjust the front wheel
support to bring the axis in an upright position.
[0005] Known wheel chairs require for such an adjustment several
screws to be loosened, the support to be adjusted and the screws
to be tightened again. Other solutions require special tools. Since
the adjustment of known wheel chairs is complicated, authorized
dealers or specialists are required to perform this task.
OBJECT OF THE INVENTION
[0006] It is an objective of the present invention to provide a
front wheel support that can more easily be adjusted.
[0007] It is another objective of the present invention to provide
a front wheel support that is stable and light weight.
SUMMARY OF THE INVENTION
[0008] The object of the invention is attained by means of the
features of claim 1 or 10.
[0009] Preferred embodiments of the wheel chair in accordance with
the invention are defined by the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will now be described in detail and with the
help of the drawings.
[0011] FIG. 1A schematically shows a first front wheel support
of a wheel chair in accordance with the invention;
[0012] FIG. 1B schematically shows a side view of the first front
wheel support of a wheel chair in accordance with the invention;
[0013] FIG. 1C schematically shows a top view of the first front
wheel support of a wheel chair in accordance with the invention;
[0014] FIG. 2 schematically shows a side view of a wheel chair
in accordance with the invention;
[0015] FIG. 3A schematically shows a side view of the first front
wheel support of a wheel chair in accordance with the invention;
[0016] FIG. 3B schematically shows a side view of the first front
wheel support of a wheel chair in accordance with the invention;
[0017] FIG. 3C schematically shows a front view of the first front
wheel support of a wheel chair in accordance with the invention;
[0018] FIG. 4A schematically shows a second front wheel support
of a wheel chair in accordance with the invention;
[0019] FIG. 4B schematically shows a partial view of the second
front wheel support of a wheel chair in accordance with the invention;
and
[0020] FIG. 5 schematically shows a third front wheel support of
a wheel chair in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] A first embodiment, according to the present invention,
is depicted in FIGS. 1A 1B, and 1C. The front wheel support 10 for
a wheel chair is depicted. Only part of a frame member 9 of the
wheel chair is visible. The front wheel support 10 comprises a first
curved part in form of a curved tube 11 being attached to the frame
member 9 of the wheel chair. In the present embodiment, the first
curved tube 11 is attached to the frame member 9 by means of welding.
The first curved tube 11 may also be an integral part of the frame
member 9. A second curved part 12, which may be a tube part or a
massive part, is provided. The curved tube 11 and the curved part
12 can be bended in the direction as depicted or in another direction.
[0022] This second curved part 12 has a first portion 12.1 with
a curvature being identical to the curvature of the first curved
tube 11. Furthermore, the first portion 12.1 has a cross section
A1 allowing the first portion 12.1 to fit inside the first curved
tube 11, as illustrated in FIG. 1B. The second curved part 12 comprises
a second portion 12.2 with a wheel fork seat for mounting a front
wheel fork of said wheel chair. The front wheel fork and the front
wheel are not visible in FIGS. 1A, 1B, and 1C.
[0023] It is important for the front wheel support 10 to be very
stable. This requires the second curved part 12 to form a tight
fit inside the first curved tube 11. This tight fit needs to be
releasable in order to allow the front wheel support 10 to be adjusted.
According to the present invention, a special securing arrangement
14 is provided. The front wheel support 10 illustrated in the FIGS.
1A, 1B, and 1C comprises a section that can be extended or expanded
when being situated inside the first curved tube 11 in order to
form a tight fit with respect to the second curved part 12. For
this reason, the first portion 12.1 has a fork-like shape with two
ends 12.3. These two ends 12.3 are spaced apart so that a screw
15 together with a conical element 16 fits between the two ends
12.3, as illustrated in FIG. 1C. When turning the screw 15, the
conical element 16 is pushed between the two ends 12.3 of the first
portion 12.1. Due to this, the two ends 12.3 are expanded and pushed
against the inner wall of the first curved tube 11. The load path
is provided between the first portion 12.1 of the second curved
part 12 and the first curved tube 11 if the screw 15 is in the right
position. The securing arrangement 14 can be released by turning
the screw 15 in the opposite direction. The two ends 12.3 will return
to their original position since the conical part withdraws.
[0024] A schematic representation of a wheel chair 20 is given
in FIG. 2. The weehl chair 20 comprises at least one front wheel
support 10, according to the present invention. This front wheel
support 16. The front wheel support 10 comprises a first curved
tube 11 being attached to the frame member 9 of the wheel chair.
In the present embodiment, the first curved tube 11 is attached
to the frame member 9. The first curved tube 11 may be an integral
part of the frame member 9, as illustrated in FIG. 2. A second curved
part 12 is provided.
[0025] This second curved part 12 has a first portion 12.1 with
a curvature being identical to the curvature of the first curved
tube 11. The second curved part 12 comprises a second portion with
a wheel fork 13 for mounting a front wheel 22 of said wheel chair
20. The wheel chair 20 further comprises a rear wheel 22.
[0026] Further details of the embodiment of FIGS. 1A through 1C
are depicted in FIGS. 3A through 3C. According to the present invention,
a special securing arrangement 14 is provided. The front wheel support
10 illustrated in the FIGS. 3A, 3B, and 3C comprises a section that
can be extended or expanded when being situated inside the first
curved tube 11 in order to form a tight fit with respect to the
second curved part 12. For this reason, the first portion 12.1 has
a fork-like shape with two ends 12.3. These two ends 12.3 are spaced
apart so that a screw 15 together with a conical element 16 fits
between the two ends 12.3, as illustrated in FIG. 3C. When turning
the screw 15, the conical part 16 is pushed between the two ends
12.3 of the first portion 12.1. Due to this, the two ends 12.3 are
pushed against the inner wall of the first curved tube 11. The load
path is provided between the first portion 12.1 of the second curved
part 12 and the first curved tube 11 if the screw 15 (not visible
in any of the FIGS. 3A through 3C) is in the right position. The
securing arrangement 14 can be released by turning the screw 15
in the opposite direction. The two ends 12.3 will return to their
original position since the conical part 16 withdraws.
[0027] Yet another embodiment is depicted in FIGS. 4A and 4B. The
first curved tube 11 is attached to the frame 9. According to this
embodiment, the second curved part 12 comprises a longitudinal slit
12.4. The securing arrangement 14 comprises a sliding element 14.1
with a threaded hole 14.2 and a screw. This screw is not visible
in the FIGS. 4A and 4B. The screw sits in a mounting piece 14.4
that is attached to the outside of the first curved tube 11. The
screw is inserted through a hole 14.5 in the mounting piece 14.4
in sits in the threaded hole 14.2 of the sliding element 14.1. and
the screw is accessible from outside through the longitudinal slit
12.4. The sliding element 14.1 moves together with the first portion
12.1 inside the first curved tube 11 up or down, if the second curved
part 12 is pushed into or pulled out of the first curved tube 11.
When the correct position of the front wheel support is reached,
the screw is tightened. Due to this, the sliding element 14.1 together
with the second curved part 12 is fixed with respect to the first
curved tube 11 and the mounting piece 14.4.
[0028] FIGS. 4A and 4B also show that the second curved part 12
comprises a second portion 12.2 with a wheel fork seat 13 for mounting
a front wheel fork of said wheel chair.
[0029] According to another embodiment, the first curved tube 11
comprises a securing arrangement 14 with a nut 17. This nut 17 sits
on the end portion 11.1 of the first curved tube 11. The end portion
of the first curved tube 11 is threaded allowing the nut 17 to be
fixed or released by turning it. Inside the first curved tube 11
there is a conical part. This conical part sits on the first portion
12.1 of the second curved part 12. When fixing the nut 17, the conical
part provides for a tight fight between the end portion 11.1 of
the first curved tube 11 and the first portion 12.1 of the second
curved part 12. The principle is similar to the one being used in
connection with garden hoses or pipes where one cylindrical piece
is to be tightly connected to another cylindrical piece in the same
manner. The difference, however, is in the dimensions and materials
used. Since the front wheel support 10 has to be stable, a more
solid and rigid version is required. |