U.S. patent application number 09/191422 was filed with the patent office on 2001-05-24 for two-piece side frame assembly for small wheelchairs.
This patent application is currently assigned to Mauricio Melgarejo. Invention is credited to MELGAREJO, ALEJANDRO, MELGAREJO, MAURICIO.
Application Number | 20010001521 09/191422 |
Document ID | / |
Family ID | 22705446 |
Filed Date | 2001-05-24 |
United States Patent
Application |
20010001521 |
Kind Code |
A1 |
MELGAREJO, MAURICIO ; et
al. |
May 24, 2001 |
TWO-PIECE SIDE FRAME ASSEMBLY FOR SMALL WHEELCHAIRS
Abstract
A sideframe for a wheelchair has a top frame and a separate
bottom frame. An axle plate extends between and is attached to both
said top and bottom frames. A caster plate is attached to the
sideframe. The top frame and the bottom frame are removably
attached to one another. In particular embodiments of the
invention, the top and bottom frames each comprise a plurality of
bolt apertures. The axle plate and the axle extension plate may
each comprise a plurality of bolt apertures. The sideframe may
support a rear-mounted major wheel, with the axle plate being to
the rear of the sideframe and the caster plate being in the front
of the sideframe. Alternatively, the sideframe may support a
front-mounted major wheel, with the axle plate being to the front
of the sideframe and the caster plate being to the rear. To mount
the top frame to the bottom frame, the top frame may have a
downwardly extending portion with a concave end piece extending
therefrom. The concave end piece is adapted to engage with the
bottom frame, which may be a tubular member. Two sideframes may be
interconnected to form a wheelchair frames. Left and right
sideframes are removably connected to one another by at least one
connecting member extending in between and connected to the first
and second sideframes, respectively. The structure of the
presently-preferred embodiment of the sideframe permits the
construction of very short sideframes for use in wheelchairs for
small children.
Inventors: |
MELGAREJO, MAURICIO; (SIMI
VALLEY, CA) ; MELGAREJO, ALEJANDRO; (SIMI VALLEY,
CA) |
Correspondence
Address: |
SCOTT R HANSEN
OPPENHEIMER WOLFF & DONELLY
2029 CENTRY PARK EAST 38TH FLOOR
LOS ANGELES
CA
90067
|
Assignee: |
Mauricio Melgarejo
|
Family ID: |
22705446 |
Appl. No.: |
09/191422 |
Filed: |
November 12, 1998 |
Current U.S.
Class: |
280/250.1 ;
280/287; 280/304.1; 280/755 |
Current CPC
Class: |
A61G 5/128 20161101;
A61G 5/125 20161101; A61G 5/1089 20161101; A61G 5/1062 20130101;
A61G 5/08 20130101; Y10S 297/04 20130101; A61G 5/00 20130101; A61G
5/1059 20130101 |
Class at
Publication: |
280/250.1 ;
280/304.1; 280/287; 280/755 |
International
Class: |
B62K 013/00; B62K
015/00; B62M 001/14 |
Claims
What is claimed is:
1. A sideframe for a wheelchair comprising: a top frame; a separate
bottom frame; and an axle plate extending between and attached to
said top and bottom frames; wherein said top frame and said bottom
frame are removably attached to one another.
2. A sideframe for a wheelchair as defined in claim 1, wherein the
vertical spacing between the bottom frame and the top frame is
approximately six inches or less, as measured from the bottom of
the bottom frame to the top of the top frame.
3. A sideframe for a wheelchair as defined in claim 1, wherein the
sideframe further comprises a caster plate attached to said
sideframe.
4. A sideframe for a wheelchair as defined in claim 1, wherein the
top and bottom frames each comprise a plurality of bolt
apertures.
5. A sideframe as defined in claim 1, wherein the axle plate and
the axle extension plate each comprise a plurality of bolt
apertures.
6. A sideframe as defined in claim 3 wherein said axle plate is to
the rear of the sideframe and said caster plate is to the front of
said sideframe.
7. A sideframe as defined in claim 3 wherein said axle plate is to
the front of said sideframe and said caster plate is to the rear of
said sideframe.
8. A sideframe as defined in claim 1 wherein said top frame
comprises an upper portion and a downwardly extended rear portion,
said downwardly-extending rear portion being removably attached to
the lower frame member.
9. A sideframe as defined in claim 8 wherein said downwardly
extending portion includes a concave end piece adapted for
engagement with said lower frame member.
10. A sideframe as defined in claim 1, wherein said caster plate is
attached to said bottom member and to said top member to
interconnect said bottom member with said upper member.
11. A wheelchair frame comprising: left and right sideframes, each
as defined in claim 1; said left and right sideframes being
removably connected to one another by at least one connecting
member extending in between and connected to the first and second
sideframes, respectively.
12. A wheelchair frame as defined in claim 11, wherein said
connecting member comprises concave end pieces.
13. A wheelchair frame as defined in claim 12, wherein said concave
end pieces each have a bolt receptor.
14. A wheelchair frame as defined in claim 11, wherein said frame
further comprises an anti-tip member extending rearwardly
therefrom.
15. A wheelchair frame as defined in claim 11, wherein said frame
further comprises an anti-tip member extending forwardly
therefrom.
16. A wheelchair frame as defined in claim 14, wherein said
anti-tip member comprises at least one wheel at an end thereof.
17. A wheelchair side frame comprising: an upper member; a lower
member separate from said upper member; said upper member being
removably interconnected with said lower member; and said sideframe
being free of welds.
18. A sideframe for a wheelchair as defined in claim 17, wherein
the vertical spacing between the bottom frame and the top frame is
approximately six inches or less, as measured from the bottom of
the bottom frame to the top of the top frame.
19. A sideframe as defined in claim 17 wherein said upper member
comprises a downwardly extending portion that includes a concave
end piece adapted for engagement with said lower frame member.
20. A sideframe as defined in claim 17 further comprising a
removable connector plate extending between and removably attached
to said upper and lower frame members to securely connect said
upper and lower frame members together.
Description
BACKGROUND OF THE INVENTION
[0001] a. Field of the Invention
[0002] The present invention relates to wheelchairs and, in
particular, to a side frame assembly constructed of sub-upper and
lower portions that are connected together without the use of
welding.
[0003] b. Prior Art
[0004] Designing wheelchairs that are both adaptable and easy to
manufacture has been particularly challenging. The typical
wheelchair frame has a side frame with an upper member, a lower
member, and one or more vertical members welded into place on the
lower and/or upper side frame members. FIG. 1 illustrates a portion
of a prior art welded frame 5 in which vertical support members 6
and 7 are welded into place. Although the vertical, welded members
are typically necessary in order to provide vertical strength to
the wheelchair frame, the welding process is time consuming and
expensive. Furthermore, once a piece is welded into place on the
side frame, it is impossible to move the location of the welded
piece. Consequently, welded wheelchair side frames are both slow to
manufacture and not versatile once the wheelchair has been
constructed.
[0005] Welded frames have been used to manufacture small
wheelchairs for children. The seat of the wheelchair is preferably
low to the ground, so that a child can easily climb into the chair.
To reduce the height of the chair, it is desirable to reduce the
height of the sideframes. One approach to making relatively short
sideframes has been to weld vertical support members between
horizontal sideframe members, as FIG. 1 illustrates. These welded
sideframes suffer from the same problems described above, namely,
they are time consuming to manufacture and have a fixed,
non-adaptable configuration.
[0006] An alternative type of sideframe is a one-piece, non-welded
sideframe having an upper portion, a lower portion and at least one
side portion. There are bends in the sideframe at the juncture of
the upper portion with the side portion, and at the juncture of the
side portion and the lower portion. The bend is typically a portion
of a circle. Sideframes having a height as measured from the bottom
of the lower portion to the top of the upper portion of
approximately nine (9) inches have been achieved with this design.
However, it is very difficult, if not impossible, to manufacture a
one-piece, non-welded design of this sort that is short enough for
a small child's wheelchair, in which the sideframe can be as short
as six (6) inches or less. The radius of curvature of the bends
that join the upper, side and lower portions would need to be
prohibitively tight for standard tubular sideframe members.
[0007] There is, therefore, a need in the art for a wheelchair side
frame design that is easier to construct and more versatile than
known wheelchair designs utilizing welds. Furthermore, there is a
need for a non-welded sideframe construction that can be used to
construct small sideframes for use in children's' wheelchairs.
SUMMARY OF THE INVENTION
[0008] In light of the problems inherent with welded sideframes,
the present invention presents an improved and more adaptable
sideframe design than is known in the art. The present invention
includes a wheelchair side frame having an upper member and a lower
member separate from the upper member. The upper member is
removably interconnected with the lower member, and the sideframe
is generally free of welds. This two-piece, nonwelded configuration
is especially useful in designing short wheelchairs for children,
although it also can be used for larger wheelchairs.
[0009] In accordance with one particular embodiment of the present
invention, a sideframe for a wheelchair has a top frame and a
separate bottom frame. An axle plate extends between and is
attached to the top and bottom frames, thereby interconnecting the
top and bottom frames. A caster plate is attached to the sideframe,
and the top frame and the bottom frame are removably attached to
one another.
[0010] The sideframe may have a variety of additional features. The
top and bottom frames may each comprise a plurality of bolt
apertures. Similarly, the axle plate and the axle extension plate
each comprise a plurality of bolt apertures. In an arrangement for
support a rear-mounted major wheel, the axle plate is to the rear
of the sideframe and the caster plate is to the front of the
sideframe. In an alternative arrangement for supporting a
front-mounted major wheel, an axle plate is to the front of the
sideframe and the caster plate is to the rear of the sideframe.
[0011] In accordance with further alternative features, the top
frame may comprise an upper portion and a downwardly extending rear
portion. The downwardly-extending rear portion may be removably
attached to the lower frame member. The downwardly extending
portion may include a concave end piece adapted for engagement with
the lower frame member, which may have a variety of different
cross-sections, including tubular. In either arrangement, the
caster plate may be attached to the bottom member and to the top
member to interconnect the bottom member with the upper member.
[0012] In accordance with another aspect of the present invention,
a wheelchair frame comprises left and right sideframes. The
sideframes are removably connected to one another by at least one
connecting member extending in between and connected to the first
and second sideframes, respectively. The connecting member may
include one or more concave end pieces adapted to interconnect with
the top and bottom members. The concave end pieces may each have a
bolt receptor. The frame may include an anti-tip member extending
rearwardly or forwardly therefrom. The anti-tip member may include
one or more wheels such that the anti-tip member rolls along the
ground with the major wheel.
[0013] The proceeding generally summarizes major points of the
invention. However, additional points and objects of the invention
may be gleaned from the Detailed Description of the preferred
embodiments, from the drawings, and from the claims. Consequently,
this Summary is not to be viewed as limiting the scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a section of a prior art welded sideframe;
[0015] FIG. 2 is a perspective view of a wheelchair frame in
accordance with the present invention;
[0016] FIG. 3 illustrates the interface between the upper and the
lower portions of the sideframe;
[0017] FIG. 4 illustrates an axle plate as used in a presently
preferred embodiment of the invention;
[0018] FIG. 5 illustrates an axle extension plate as used in a
presently preferred embodiment of the invention;
[0019] FIG. 6 illustrates a presently preferred castor plate;
[0020] FIG. 7 is an exploded view of a connector member and
associated end pieces for joining the left and right sideframe
portions;
[0021] FIG. 8 is a detail view of an end piece; and
[0022] FIG. 9 illustrates an alternative plate for use in a
major-wheel-forward embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring to FIG. 1, a wheelchair 10 has left and right
wheels 12 and 14 and a seat 16. A lower frame 18 includes a left
side frame 20 and a right side frame 22. Small forward wheels 24
and 26 extend from casters 28 and 30 respectively. A single piece
footrest 32 extends between the left and right footrest hangers 34
and 36, respectively.
[0024] Each of the side frames 20 and 22 have respective upper
frame members 40 and 42, respectively, and lower sideframe members
44 and 46, respectively. The lower frame members 44, 46 are spaced
by spacer members 50 and 52, respectively. The upper frame members
40 and 42 are spaced and interconnected by spacer bar 54.
[0025] The wheelchair is stabilized by anti-tip members 60 and 62,
respectively, each of which is generally a rearwardly extending
member having stabilization wheels. These anti-tip members 60 and
62 prevent the wheelchair from tipping backwards during use.
[0026] The respective upper and lower sideframe members are
interconnected without the use of welds. Considering the left
sideframe, and referring to FIG. 3, the upper frame portion 40 and
the lower frame portion 44 are interconnected at a juncture point
46. The upper member 40 in the preferred embodiment is a tubular
member that is hollow inside. Tubular members for wheelchair frames
are well-known in the art, although a presently preferred
embodiment of the invention incorporates tubular members having a
diameter of 1" and a wall thickness of {fraction (1/16)}".
[0027] Extending from the end of member 40 at juncture point 46 is
an end piece 48. The end piece 48 is shown in detail in FIG. 8. The
end piece 48 has a convex surface 50 having a threaded bolt
receptor 52. The member 48 also has a neck portion 54 that is sized
so as to fit within the tubing that forms a members of the side
frame. A bolt aperture 56 extends through the neck portion 54 such
that a bolt may be inserted through aperture 56 to secure the
member 48 within the tube within which the member is to reside. An
optional indentation 58 may be provided to accommodate a
spring-loaded pin type of retaining system. FIG. 7 illustrates how
end pieces 60 and 62 are inserted into respective ends 64 and 66 of
member 50. Respective bolts 68 and 70 are inserted through opening
in the tube 50 through the apertures 72 and 74, respectively, in
the members 60 and 62, and then through bottom openings in the tube
50. Nuts 76 and 78 secure the bolts 68 and 70 into place.
[0028] Returning to FIG. 3, a bolt 80 is inserted through the
tubular member 44 and into the end piece 46 in order to
interconnect member 44 with upper member 40. However, the end piece
46 and bolt 80 combination is only one means for securing the
members 40 and 44 together. The upper and lower members are also
secured together by way of an axle plate 82, which extends between
and is bolted to both members 44 and 40.
[0029] Referring to FIG. 4, the axle plate 82 has a plurality of
holes along each longitudinal side 84 and 86. This plurality of
holes 84 and 86 provides the user with flexibility as to where the
plate will be attached to the respective frame members 40 and 44.
For example, if the spacing between members 40 and 44 in a
particular embodiment is especially short, the user may use the
same plate 82 to join the two members together. The user simply
reduces the spacing between the holes along the plurality of holes
84 and 86 and inserts bolts to hold the plate onto the frame
members. In this way, the present system for interconnecting the
members 40 and 44 is particularly versatile. Compared to systems in
which members are welded, the use of the members such as 82 greatly
simplifies the manufacturing process. To modify the way in which
members 44 and 40 are joined together, the user simply unbolts
member 82, and then is free to move member 82 forward or backward
as the situation requires. This flexibility is simply impossible in
frames that are welded.
[0030] Considering member 82 further, an elongated opening 88 is
provided through the center of member 82. The opening 88 is wide
enough to accommodate an axle sheath receptor into which an axle
may be inserted. The axle sheet receptor, as seen in FIG. 3, has
reference numeral 90 and serves to accommodate the axle of the
wheel 12 (not shown). An axle extension plate 92 is bolted onto
axle extension plate 82 to provide means for retaining a wheel
axle. The plate 92 includes sets of holes 94 and 96 and an
alternative axle opening 98 which can be used to accommodate a
wheel axle in some embodiments of the invention. Like the axle
plate 82, the axle extension plate 92 is designed to provide the
user with considerable flexibility and adaptability. The plurality
of holes 94 and 96 permit the user to vary the way in which the
axle extension plate 92 is mounted onto the axle plate 82. In most
embodiments, the axle extension plate 92 is secured onto axle plate
82 with four simple bolts. However, with the plurality of holes 94
and 96, the user can secure the axle extension plate 92 onto the
axle plate 82 using more than four bolts, or potentially fewer
bolts.
[0031] The axle extension plate 92 serves to provide an axle sheath
receptor 90 for receiving and retaining a wheel axle. In an
alternative embodiment, the axle plate 82 may itself be provided
with the axle sheath receptor 90 so as to unify the functions of
plates 82 and 92. However, in the presently preferred embodiment, a
separate axle plate and an axle extension plate are employed.
[0032] Returning now to FIG. 2, an additional means for securing
the respective lower side frame members 44 and 46 to the respective
upper side frame members 40 and 42 are caster plates 38 and 30,
respectively. Turning to FIG. 6, a caster plate 38 includes a
plurality of bolt holes 100 about the perimeter thereof. As with
the axle plate 82 and the axle extension plate 92, the apertures in
caster plate 38 provide the user with considerable flexibility in
manufacture. One caster plate 38 may be used in any of variety in
wheelchair designs because the plurality of bolt apertures 100
provide the manufacturer with a variety of connection points from
which to choose. The caster plate 38 is provided with a central
opening 102 through which the respective caster 28 may be
mounted.
[0033] By way of illustrative dimensions, and not by limitation,
the following components in one small wheelchair embodiment of the
invention may have the following particular dimensions. It should
be noted, however, that the present invention is not limited to any
one embodiment. The wheels are approximately 16 inches in diameter.
The lower sideframe members are approximately 17 inches long. The
space between the left and right sideframes is approximately
101/4inches. The space between the upper and lower side frame
members is approximately 5 inches, as measured from the center of
the upper tube to the center of the bottom tube, or 6 inches as
measured from the bottom of the bottom tube to the top of the upper
tube. The upper and lower sideframe members are hollow metal tubes
having a diameter of approximately one inch. The axle plate is
approximately 63/4inches long by 2 1/2inches wide.
[0034] It is generally noted that the above dimensions pertain to a
presently preferred embodiment of the invention. The structure of
the sideframe design presented herein permits the very short
spacing between the upper and lower sideframe members described
above. The six-inch top-to-bottom sideframe spacing of the
presently preferred embodiment is considered to be a noteworthy
achievement in the art, particularly with the presently preferred
adaptable, non-welded sideframe.
[0035] The foregoing has described one presently preferred
embodiment of the present invention. However, it is to be
understood that the present invention is not limited to any one
embodiment. Consequently, various improvements and changes may be
made. For example, the embodiment illustrated in FIG. 2 has the
major wheels 12 and 14 mounted to the rear of the wheel chair and
the minor caster wheels 24 and 26 mounted at the front of the
wheelchair. However, in some embodiments, and especially in
embodiments for small children, it is desirable to mount the major
wheels 12 and 14 on the front of the wheelchair, and to move the
smaller caster wheel 24 and 26 to the rear of the wheelchair. In
such an embodiment, the anti tip members 60 and 62 will be mounted
in the front, rather than the back of the wheelchair, such that the
members 60 and 62 extend forwardly with the wheels thereof being in
front of the wheelchair.
[0036] Thanks to the versatility of the present invention, it is a
simple matter for a manufacturing standpoint to reconfigure the
wheelchair into a forward wheel design. The respective axle plates
and their corresponding axle extension plates are simply moved
forward along their respective side frames and bolted to the front
rather to the rear of the frame. To move the caster wheels 26 and
24 backwardly an additional caster plate is added to the rear of
the frame. FIG. 9 illustrates a caster plate 110 that can be added
to the rear of the frame to support the casters 28 and 30. The
caster plate 110 is provided with a plurality of apertures for
mounting the plate onto the side frame and for mounting the casters
to the respective additional caster plates as illustrated in FIG.
9. In this alternative embodiment, it is preferred that the
respective side frame portions 40 and 42 be provided with
sufficient apertures along the rear portions thereof for mounting
the additional caster plate.
[0037] Various other modifications may be made. For example, the
one piece footrest 32 may just be easily be broken into separate
left and right footrests. The respective handles may be made to be
foldable or rotatable forward, as desired. The relative sizes of
the wheels 12 and 14 may be made larger or smaller as the need
arises. The design may be adapted to construct folding wheelchairs,
for example, rather than the rigid configuration as shown.
Consequently, it is to be understood that the present invention is
not limited to the preferred embodiment illustrated herein.
[0038] It should be further noted that although the drawings
illustrate one embodiment of the invention, these are not
engineering production drawings. Consequently, the relative
dimensions that the drawings illustrate are not necessarily those
that would be used in production.
* * * * *