BACKGROUND OF THE INVENTION
[0001] Wheelchair attachments coupled to wheelchair frames are used to support trays, recepticles
and other equipment within reach of an individual confined to the wheelchair. In order
to maximize the advantages of these attachments it is necessary that they be easily
adjustable to various verticle, horizontal, angular and combined positions relative
to the individual. That is to say, the attachments should be substantially universally
adjustable.
[0002] Attachments for the purposes intended are known, but are less than universally adjustable,
and the available adjustment is not easily accomplished. The attachment described
in U.S. Patent 4,458,870 issued to Leroy R. Dugan on July 10, 1984, for example, is
adjustable in several linear and angular directions by means of lever advantaged forces
and friction joints which require tools for the adjustment. These features can be
distinct disadvantages, particularly for individuals who desire self-sufficiency and
prefer to make the required adjustments without the assistance of others. The present
invention overcomes these disadvantages.
[0003] Accordingly, it is the object of this invention to provide a wheelchair attachment
for supporting equipment used by an individual confined to the wheelchair, and which
attachment is substantially universally adjustable, with the adjustment being accomplished
more easily than has heretofore been the case.
SUMMARY OF THE INVENTION
[0004] This invention contemplates a universally adjustable wheelchair attachment of the
type which is coupled to the wheelchair frame for supporting equipment or the like
for use by an individual confined to the wheelchair. The attachment has three friction
joints. A first and second of these friction joints are adjusted by a wrench and a
third is adjusted by a knob. A pair of columns coupled by the first joint are adjusted
longitudinally and rotationally through an arrangement of collars and collar arms.
One of the columns is coupled by the second joint to the wheelchair through a rotationally
adjustable block. The other of the columns is coupled through the third joint to rotationally
adjustable equipment support member.
BRIEF DESCRIPTION OF THE DRAWING
[0005]
Figure 1 is a plan view of a universally adjustable wheelchair attachment according
to the invention.
Figure 2 is a partial end view of one of the first and second friction joints.
Figure 3 is a partial end view of the other of the first and second friction joints.
DETAILED DESCRIPTION OF THE INVENTION
[0006] With reference to Figure 1, a wheelchair member is designated by the numeral 2. Wheelchair
member 2 may be a horizontal or vertical portion of a wheelchair such as a wheelchair
armrest made of metal tubular or bar stock. The wheelchair attachment of the invention
is secured to member 2 as will next be explained.
[0007] An attachment block 4 includes a recess 6 which receives wheelchair member 2. A strap
8 fits over wheelchair member 2 and is secured to block 4 by screws or the like 10,
whereby block 4 is securely fastened to the wheelchair member in a rotational position
relative thereto.
[0008] Block 4 has a hole 12 at one end thereof for receiving a bar 14. Bar 14 is secured
in block 4 by means of a set screw (not shown) tightened by a block arm 16. With the
arrangement shown, bar 14 can be rotationally displaced about the longitudinal axis
of bar 14 in opposite directions as shown by arrows (a) and (b) so as to orient the
wheelchair attachment relative to wheelchair member 2, as will now be understood.
[0009] A column 17 includes a tube 18 having a yoke 20 at one end thereof, as best shown
in Figure 2. Bar 14 is received in yoke 20 and is separated on either side thereof
by washers 22 which may be spring-type washers for purposes to be hereinafter explained.
A bolt 24 enters one side of yoke 20, extends through washers 22 and bar 14 and extends
through the other side of the yoke where it is secured thereto by a washer 25 and
a nut 26 which may be tightened and loosened by a conventional open end wrench. With
the arrangement shown, column 17 may be angularly displaced away from and toward bar
14 as indicated by arrows (c) and (d) in Figure 1.
[0010] Tube 18 of column 17 receives in telescopic fashion a bar 28. Bar 28 is logitudinally
displaceable within tube 18 as shown by arrows (e) and (f) in Figure 1. Bar 28 is
secured in a desired longitudinal position within tube 18 by a collar 30. Colalr 30
may be a conventional split collar which is tightened against tube 18 to squeeze the
tube against the bar and to thereby hold bar 28 in the desired position by a collar
arm 32 which tightens a set screw (not shown). With the arrangement shown, bar 28
can be rotationally displaced about its longitudinal axis as shown by arrows (g) and
(h) in Figure 1 and secured in a desired rotational position by tightening collar
30.
[0011] A column 33 includes tube 34 having a yoke 36 at one end thereof as best shown in
Figure 3. Bar 28 is received in yoke 36 and is separated on either side therof by
washers 38 which ray likewise be spring-type washers. A bolt 40 enters one side of
yoke 36, extends through washers 38 and bar 28 and extends through the other side
of the yoke where it is secured thereto by a washer 41 and a nut 42 which is loosened
and tightened by a conventional open end wrench. With the arrangement shown, tube
34 may be angularly displaced away from or toward bar 28 as indicated by arrows (i)
and (j) in Figure 1.
[0012] Tube 34 receives in telescopic fashion a bar 44. Bar 44 -is longitudinally adjustable
within tube 34 as shown by arrows (k) and (1) in Figure 1. Bar 44 is secured in a
desired longitudinal position within tube 34 by a conventional split collar 46 which
is tightened against tube 34 to squeeze the tube against the bar and to thereby hold
bar 44 in the desired position by a collar arm 48 which tightens a set screw (not
shown). With the arrangment shown bar 44 can be rotationally displaced about its longitudinal
axis as shown by arrows (m) and (n) in Figure 1 and secured in a desired rotational
position by tightened collar 46.
[0013] The end of bar 44 is received by a yoke 50 and is separated on either side thereof
by spring washers 52. A bolt 54 enters one side of yoke 50, extends through washers
52 and bar 44 and extends through the other side of the yoke, with a knob 56 being
secured to the extending end of the bolt. With the arrangement shown, yoke 50 may
be displaced about the axis of bolt 54 through knob 56 as shown by arros (o) and (p)
in Figure 1.
[0014] A supporting plate 60 is secured to yoke 50 by means of a screw 62 and a wing nut
64. Supporting plate 60 may be used to support equipment used by the individual confined
to the wheelchair. In this connection, it will be understood that the equipment may
be adapted to be fastened to the plate through screw 62 and wing nut 64 as will now
be understood.
[0015] As will now be seen from the aforegoing description of the invention that three friction
joints are provided for adjustment of the wheelchair attachment. That is to say, the
joint joining bar 14 and column 17; the joint joining column 17 and column 33; and
the joint joining column 33 and yoke 50. The first two of these joints are tightened
and loosened by an open end wrench and the last mentioned joint is tightened and loosened
by a knob.
[0016] In this connection it is noted that the aforementioned joints include spring washers
22, 38 and 52 respectively, which separate the bars 14, 28 and 44 from the respective
yokes 20, 36 and 50. The spring washers provide a friction force to maintain a desired
angular position, but yet do not provide a positive lock in said position whereby
an extensive amount of force is required to displace the bar to another angular position
as may be desired. This feature of the invention is of importance since it results
in less frequent tightening and loosening of nuts 42 and 46 and knob 56 for adjustment
purposes as is desireable.
[0017] The tightening and loosening of block 4 and collars 30 and 46 can be accomplished
with relative ease due to the mechanical advantage offered by arms 16, 32 and 48 respectively.
In this connection it will be understood that the set screws associated with the arms
may be made integral therewith as be welding or the like, whereby loss of the arm
and/or set screw is minimized.
[0018] With reference to Figures 1 and 2 it will be seen that the portion of bar 14 received
by yoke 20 carries a pair of flat areas 66. Flat areas 66 extend the abutting surface
between bar 14 and washers 22 to enhance the friction locking of column 17 in a desired
position relative to bar 14 as will now be understood. Although not shown in the drawing,
bar 28 and bar 44 may likewise carry such flat areas for the purposes intended.
[0019] It will now be seen from the aforenoted description of the invention that a substantially
universally adjustable wheelchair attachment is provided, with the adjustment being
accomplished more easily than as heretofore been the case. By virtue of the arrangement
described, an infinite number of vertical, horizontal, angular and combined positions
of the attachment relative to the wheelchair are possible. The arrangement thereby
enhances the use of the attachment in that is is capable of supporting a variety of
equipment in a variety of positions. Further, the arrangement enhances adjustment
by those confined to the wheelchair without the necessity of assistance of others
as is desireable.
[0020] With the above description of the invention in mind, reference is made to the claims
appended hereto which define the scope of the invention.
[0021] The figures used in the claims are only meant to explain more clearly the intention
of the invention and are not supposed to be any restriction concerning the interpretation
of the invention.
1. U universally adjustable wheelchair attachment which supports equipment for use
by one confined to the wheelchair, characterized by:
a first column including a longitudinally and rotationally displaceable member;
a second column including a longitudinally and rotationally displaceable member;
a first friction joint for coupling one of the first and second columns to the longitudinally
and rotationally displaceable member of the other of the first and second columns,
whereby said columns are angularly displaceable relative to each other;
means coupled to the wheelchair;
a second friction joint for coupling the other of the first and second columns to
the means coupled to the wheelchair, whereby said column and said means are angularly
displaceable relative to each other;
equipment supporting means; and
a third friction joint for coupling the longitudinally and rotationally displaceable
member of the one of the first and second columns to the equipment supporting means,
whereby said column and said supporting means are angularly displaceable relative
to each other.
2. A universally adjustable wheelchair attachment as described by claim 1, wherein
each of the first and second columns is characterized by:
a tubular member having a yoke at one end thereof and receiving the longitudinally
and rotationally displaceable member in telescopic fashion at the other end; and
collar means for securing said longitudinally and rotationally displaceable member
in a predetermined longitudinal and rotational displacement within the tubular member.
3. A universally adjustable wheelchair attachment as described by claim 2, wherein
the first friction joint is characterized by:
the yoke of the one of the first and second columns receiving the longitudinally and
rotationally displaceable member of the other of the first and second columns;
resilient means disposed between the yoke and the longitudinally and rotationally
displaceable member; and
means for coupling said yoke, said member and said resilient means, whereby the first
and second columns are frictionally maintained at a predetermined angular displacement
relative to each other.
4. A universally adjustable wheelchair attachment as described by claim 2, wherein
the second friction joint is characterized by:
the yoke of the other of the first and second columns receiving the means coupled
to the wheelchair;
resilient means disposed between the yoke and the means coupled to the wheelchair;
and
means for coupling said yoke, said means and said resilient means, whereby the other
column and the means coupled to the wheelchair are frictionally maintained at a predetermined
angular displacement relative to each other.
5. A universally adjustable wheelchair attachment as described by claim 2, wherein
the third friction joint is characterized by:
the equipment supporting means including a yoke;
the yoke receiving the longitudinally and rotationally displaceable member of the
one of the first and second columns:
resilient means disposed between the yoke and said longitudinally and rotationally
displaceable member; and
means for coupling said yoke, said member and said resilient means, whereby the one
column and the equipment supporting member are frictionally maintained at a predetermined
angular displacement relative to each other.
6. A universally adjustable wheelchair attachment which supports equipment for use
by one confined to the wheelchair, characterized by:
a first column including a tubular member having a yoke at one end thereof and a longitudinally
and rotationally displaceable member received in telescopic fashion at the other end;
a second column including a tubular member having a yoke at one end thereof and a
longitudinally and rotationally displaceable member received in telescopic fashion
at the other end;
first collar means associated with the first column for securing the telescopic member
thereof at a predetermined longitudinal and rotational displacement;
second collar means associated with the second column for securing the telescopic
member thereof at a predetermined longitudinal and rotational displacement;
the yoke of the first column receiving the longitudinally and rotationally displaceable
member of the second column;
means coupled to the wheelchair;
the yoke of the second column receiving the means coupled to the wheelchair;
equipment supporting means including a yoke;
the yoke of the equipment supporting means receiving the longitudinally and rotationally
displaceable member of the first column;
first means for coupling the yoke of the first column and the member of the second
column, whereby said first and second columns are frictionally maintained at a predetermined
angular displacement relative to each other;
second means for coupling the yoke of the second column to the means coupled to the
wheelchair, whereby said second column and said means are frictionally maintained
at a predetermined angular displacement relative to each other; and
third means for coupling the yoke of the equipment supporting means and the member
of the first column, whereby said first column and said means are frictionally maintained
at a predetermined angular displacement relative to each other.