Note: Descriptions are shown in the official language in which they were submitted.
CA 02298149 2000-02-09
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PIVOTABLE ABDUCTION ABUTMENT SUPPORT
FOR WHEELCHAIR OR THE LIKE
s FIELD OF THE INVENTION
The present invention relates to a pivotable abduction abutment support for
preventing injury during the abduction movement of the legs of a handicapped
person sitting on a chair, a wheelchair, a base on wheels, or the like.
io
BACKGROUND OF THE INVENTION
Some handicapped persons have muscular contraction problems that make
them contract their legs together (this movement is known as abduction) and
hit
is their knees. Such contraction can hurt them involuntarily and to prevent
this,
there are different abduction abutment supports. The support places the
abutment between the legs of the person and prevents the knees from hitting
each other. Some known abutment supports are fixed to the seat, such as the
one described in Wilkie et al. US patent no. 5,636,900, and may not pivot
zo downwardly in order to be moved out of the way of the person when it is
necessary.
Other known abutment supports may pivot downwardly to clear the way of the
person sitting on the wheelchair so he or she can move out or move on the
?s wheelchair easily. These pivotable abutment supports are provided with a
locking mechanism that locks the abutment between the legs of the person and
can be unlocked in order to move the abutment out of the way when desired.
The locking means of one known pivotable abutment support comprises a
~o protuberance on one side of a lower end of a rod and two plates sandwiching
the lower end of the rod. One plate has a recessed area adapted to receive the
protuberance. An abutment is mounted on an upper end of the rod. When the
CA 02298149 2000-02-09
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rod is extended upwardly and the abutment lies above the seat, the
protuberance fits into the recessed area and maintains the rod in the
upstanding
position, i.e. between the legs of the person. To unlock the rod, one has to
press
behind the abutment and pivot the rod downwardly so that the protuberance
s disengages the recessed area. One of the disadvantages of this locking means
is that the protuberance is subject to wear and tear rapidly and consequently
loses its effectiveness very rapidly.
The pivotable abutment support described in Kornberg US patent no. 5,320,416
to has a different locking mechanism to keep the rod between the legs (or
knees)
of the person. Its locking mechanism comprises a rail system designed to
longitudinally forwardly and rearwardly adjust the abutment location, a
sliding
member fixed to a rod on which an abutment is mounted and adapted to slide in
the rail system. At a forward limit position of the rail system, the sliding
member
is disengages the rail and may freely pivot downwardly together with the rod
and
the abutment that are fastened to the sliding member. To keep the rod upwardly
extending, the sliding member has to be pushed rearwardly in order to engage
the rail. Then, the sliding member is secured in a longitudinal desired
position on
the rail system by a locking pin engaging it.
zo
The pivotable abutment support described in Suhre US patent no. 4,617,919
uses another locking means which comprises a release pin allowing the rod to
pivot downwardly.
Zs There is a need for a locking means for a pivotable abduction abutment
support
that does not wear and tear easily, and is simple to manipulate.
Advantageously,
the locking means is unlocked by using only one hand, and is locked
automatically when the rod is pivoted back into the upstanding position.
~o
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SUMMARY OF THE INVENTION
s The present invention is directed to a pivotable abduction abutment support
for a
chair or the like that satisfies the above-mentioned needs.
In accordance with the present invention, this object is achieved with a
pivotable
abduction abutment support for a chair. The chair has a seat. The support
Io comprises:
- a base member adapted to be fastened under the seat, the seat having
a front edge, the base member having a front end extending beyond the front
edge of the seat;
- a rod having two opposite ends, a front surface and a rear surface, one
is of the opposite ends being mounted about a first pivot located at the front
end of
the base member, the first pivot having a pivoting axis parallel to the front
edge
of the seat, wherein the rod pivots between an upstanding position where the
rod extends upwardly and substantially vertically, and a released position
where
the rod extends downwardly;
zo - abutment fastening means for fastening an abutment to the other
opposite end of the rod so that the abutment extends above the seat when the
rod is in the upstanding position; and
- releasable locking means for releasably locking the rod in the
upstanding position, the locking means comprising:
zs (i) a retaining portion for engaging the front surtace of the rod, the
retaining portion lying above the first pivot in order to lock the rod in the
upstanding position,
(ii) at least one arm extending rearwardly from the retaining portion, the
arm having a distal end mounted about a second pivot located on the base
~o member rearwardly of the first pivot, and
(iii) biasing means for biasing the retaining portion against the rod,
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whereby, by manually pivoting the retaining portion away from the rod, the rod
is
released and free to pivot downwardly; and when the rod is pivoted from the
released position to the upstanding position, the biasing means automatically
pivots the retaining portion towards the rod to engage the front surface of
the rod
s and thereby lock the rod in the upstanding position.
In accordance with the present invention, this object is also achieved with
another pivotable abduction abutment support for a chair having a seat. The
support comprises:
io - a base member adapted to be fastened under the seat, the seat having
a front edge, the base member having a front end extending beyond the front
edge of the seat, the front end having a front surface and a lower surface
where
the front surface is inwardly rounded towards the lower surface, the base
member having two opposite sides;
is - a rod having two opposite ends, a front surface and a rear surface, one
of the opposite ends being mounted about a first pivot located at the front
end of
the base member, the first pivot having a pivoting axis parallel to the front
edge
of the seat, wherein the rod pivots between an upstanding position where the
rod extends upwardly and substantially vertically, and a released position
where
2o the rod extends downwardly;
- abutment fastening means for fastening an abutment to the other
opposite end of the rod so that the abutment extends above the seat when the
rod is in the upstanding position;
- releasable locking means for releasably locking the rod in the
zs upstanding position, the locking means comprising:
(i) a retaining portion for engaging the front surface of the rod, the
retaining portion lying above the first pivot in order to lock the rod in the
upstanding position,
(ii) two arms extending rearwardly from two opposite sides of the retaining
,o portion so that the locking means defines a U shape, each arm having a
distal
end mounted about a second pivot located on the base member rearwardly and
,, CA 02298149 2000-02-09
upwardly of the first pivot, the second pivot having a pivoting axis parallel
to the
pivoting axis of the first pivot, and
(iii) biasing means for upwardly biasing the retaining portion,
whereby, by manually pivoting down the retaining portion, the rod is released
5 and free to pivot downwardly; and when the rod is pivoted from the released
position to the upstanding position, the biasing means automatically pivot the
retaining portion upwardly to engage the front surface of the rod and thereby
lock the rod in the upstanding position;
and
to - two flanges laterally extending from an upper edge of the two opposite
sides of the base member respectively, whereby the flanges prevent the locking
means from pivoting upwardly beyond a horizontal position.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of the pivotable abduction abutment
support
according to a first preferred embodiment of the present invention, where the
rod
is in the upstanding position.
2o Figure 2 is a side elevational view of the support shown in Figure 1, where
the
locking means is unlocked.
Figure 3 is a side elevational view of the support shown in Figures 1 and 2,
where the rod is partially pivoted downwardly.
Figure 4 a side elevational view of the support shown in Figures 1, 2 and 3,
where the rod is in the released position.
Figure 5 is a side front perspective view of the support shown in Figures 1,
2, 3
~o and 4, mounted on a wheelchair seat.
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Figure 6 is a rear bottom perspective view of a portion of the support shown
in
Figures 1, 2, 3, 4 and 5, where the locking means is partially pivoted
downwardly.
s
Figure 7 is a side elevational view of the support according to a second
preferred embodiment of the present invention, where the rod is in the
upstanding position.
io Figure 8 a side elevational view of the support shown in Figure 7, where
the rod
is in the released position.
Figure 9 is a side front perspective view of the pivotable abduction abutment
support shown in Figures 7 and 8, mounted on a wheelchair seat.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
OF THE INVENTION
A pivotable abduction abutment support (10) according to the present invention
2o is designed to be installed underneath a seat (1 ) of a chair. The term
"chair" is
used in the context of the present invention to designate a typical chair, a
wheelchair, a base on wheels, or any other chair-like device. However, the
support (10) of the present invention is particularly useful for a person
sitting on
a wheelchair (not shown).
Referring to Figure 1, the pivotable abduction abutment support (10) comprises
a base member (12) adapted to be fastened under the wheelchair's seat (1 ).
Usually, the seat (1 ) includes a rigid part (5) and a cushion part (3) as
indicated
in Figure 1. Preferably, the base member (12) is fastened under the seat (1 )
by
3o means of screws (14) being inserted across holes (16) made in the base
member (1 ) and screwed to the seat (1 ). The seat (1 ) has a front edge (2),
and
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the base member (1 ) has a front end (18) extending beyond the front edge (2)
of
the seat (1 ).
Referring to Figure 2, the support (10) further comprises a rod (20) having
two
s opposite ends (22 and 24), a front surface (26) and a rear surface (28). One
of
the opposite ends (22) of the rod (20) is mounted about a first pivot (30)
located
at the front end (18) of the base member (12). The first pivot (30) has a
pivoting
axis A parallel to the front edge (2) of the seat (1 ) as illustrated in
Figure 5, so
that the rod (20) can pivot between an upstanding position (shown in Figures 1
io and 5) where the rod (20) extends upwardly and substantially vertically,
and a
released position (shown in Figure 4) where the rod (20) extends downwardly.
It
should be understood by the expression "substantially vertically"
characterising
the rod (20) in the upstanding position, that a strict vertical orientation of
the rod
(20) is not an essential requirement of the invention. What is essential is
that the
is abutment (4) lies between the user's legs.
Referring to Figure 2, the support (10) also comprises abutment fastening
means for fastening an abutment (4) to the other opposite end (24) of the rod
(20) so that the abutment (4) extends above the seat (1 ) when the rod (20) is
in
2o the upstanding position. Preferably, the abutment fastening means are
embodied by a hollow piece (32) covering the other opposite end (24) of the
rod
(20) and being maintained at a desired height along the rod (20) by means of a
tightening bolt (34) extending inwardly and frictionally engaging one of the
surfaces of the rod (20). Still according to this preferred embodiment of the
Zs abutment fastening means, an abutment (4) is mounted on the hollow piece
(32)
by means of screws (36).
Preferably, the rod (20) has a variable height in order to vertically adjust
the
height of the abutment (4). One way to vertically adjust the abutment (4) is
to
~o use a telescopic rod. Alternatively, the rod (2) will be supplied with a
predetermined length, which is long, and can be appropriately shortened for
the
, CA 02298149 2000-02-09
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user and the chair for which it is intended (in this case, the rod is not
adjustable
per se).
Now referring to Figures 1 to 6, the support (10) comprises releasable locking
s means for releasably locking the rod (20) in the upstanding position. The
locking
means basically comprise (i) a retaining portion (40) for engaging the front
surface (26) of the rod (20), (ii) at least one arm (42) extending rearwardly
from
the retaining portion (40) and being pivotally mounted on the base member (12)
and (iii) biasing means for biasing the retaining portion (40) against the rod
(20).
io
By manually pivoting the retaining portion (40) away from the rod (20), the
rod
(20) is released and free to pivot downwardly. When the rod (20) is pivoted
from
the released position (shown in Figure 4) to the upstanding position (shown in
Figure 1 ), the biasing means automatically pivot the retaining portion (40)
is towards the rod (20) to engage the front surface (26) of the rod (20) and
thereby
lock the rod (20) in the upstanding position.
More particularly, the retaining portion (40) engages the front surface (26)
of the
rod (20) and lies above the first pivot (30) in order to lock the rod (20) in
the
zo upstanding position as shown in Figure 1.
Referring more particularly to Figures 1, 2, 3 and 4, the at least one arm
(42)
extends rearwardly from the retaining portion (40) and has a distal end (44)
mounted about a second pivot (46). It is to be understood that the at least
one
zs arm (42) can have a shape different than the one suggested in the Figures 1
to
4 without departing from the scope of the invention.
Now referring to Figure 3, the second pivot (46) is located on the base member
(12) rearwardly of the first pivot (30) so that the pivoting radius X of the
retaining
~o portion (40) is greater than the pivoting radius Y of the rod (20). Because
of this
requirement, the rod (20) can not push the retaining portion (40) and force it
to
pivot downwardly.
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According to a first preferred embodiment of the invention, the locking means
comprise two arms (42) extending rearwardly from two opposite sides (48) of
the
retaining portion (40) so that the locking means define a U shape as more
s clearly shown in Figure 6. Thus, the U shape of the locking means partially
surrounds the rod (20) when the rod (20) is locked in the upstanding position.
Still according to the first preferred embodiment of the invention which is
shown
in Figures 1 to 6, the second pivot (46) has a pivoting axis B parallel to the
io pivoting axis A of the first pivot (30); the pivoting axis A and B being
specifically
illustrated in Figure 5. In the first preferred embodiment of the invention,
the
second pivot (46) is preferably also located above of the first pivot (30).
Referring to Figure 6, the biasing means is preferably a spring (50) coiled
is around the pivot (46). The spring (50) has one end leaning on the base
member
(12) and another end fixed into one arm (42) of the locking means. However,
alternative configurations for a spring or any other biasing means would fall
within the scope of the invention.
?o Now referring to Figure 3, the front end (18) of the base member (12) has a
front
surface (17) and a lower surface (19) and the front surface (17) is preferably
inwardly rounded towards the lower surface (19).
Now referring to Figures 5 and 6, the base member (12) preferably has two
2s opposite sides (11 ) and comprises at least one flange (52) laterally
extending
from an upper edge (13, shown only in Figure 6) of an opposite side (11 ) of
the
base member (12), whereby the flange (52) prevents the locking means from
pivoting upwardly beyond a horizontal position. Preferably, the base member
(12) comprises two flanges (52) laterally extending from an upper edge (13) of
~o the two opposite sides (11 ) of the base member (12) respectively. These
flanges
(52) are preferably used to include the holes (16) for fastening the base
member
(12) under the seat (1 ).
CA 02298149 2000-02-09
In a second preferred embodiment of the invention shown in Figures 7 to 9, the
elements of the locking means are numbered with a prime after the number.
Thus, the locking means according to the second preferred embodiment
s comprise (i) a retaining portion (40'), (ii) an arm (42') extending
rearwardly from
the retaining portion (40') and having a distal end (44' shown in Figure 7)
mounted about a second pivot (46' shown in Figures 7 and 8 only); the second
pivot (46') having a pivoting axis B'.
to According to the second preferred embodiment of the invention and referring
more particularly to Figures 7 and 8, the pivoting axis B' of the second pivot
(46')
is vertical, i.e. orthogonal to a horizontal plane in which the pivoting axis
A of the
first pivot (30) extends.
is In the second preferred embodiment, the biasing means is preferably a
spring
(not shown) coiled around the pivot (46') in a similar fashion to the spring
(50)
illustrated in Figure 6. To stop the retaining portion (40') in front of the
front
surface (26) of the rod (20), the base member (12) is provided with a stopper
(54') shown in Figure 9.
In the first preferred embodiment of the invention shown in Figures 1 to 6,
the
biasing means bias the retaining portion (40) upwardly and for setting the rod
(20) free, the retaining portion (40) has to be pivoted down. Whereas, in the
second preferred embodiment of the invention shown in Figures 7 to 9, the
2s biasing means bias the retaining portion (40') toward the left side, and
thus, for
setting the rod (20) free, the retaining portion (40') has to be pivoted
toward the
right side.
Although not shown, the pivotable abduction abutment support (10) according to
,o the present invention can comprise extending means (not shown) for
extending
forwardly the base member (12) in order to adjust horizontally the distance
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between the abutment (4) and the wheelchair user. These extending means can
be embodied in a rail system interconnecting two parts of the base member
(12),
or in a telescopic fastening means for horizontally extendingly fastening the
base member (12) under the wheelchair seat (1 ). Other extending means known
s in the art may be used in combination with the disclosed support (10)
without
departing from the scope of the present invention.
Also not shown, the pivotable abduction abutment support (10) according to the
present invention can comprise moving means (not shown) for laterally moving
to the base member (12) in order to laterally adjust the abutment (4) along
the front
edge (2) of the seat (1 ).
Although a preferred embodiment of the invention has been described in detail
herein and illustrated in the accompanying drawings, it is to be understood
that
is the invention is not limited to this precise embodiment and that various
changes
and modifications may be effected therein without departing from the scope or
spirit of the invention as defined in the appended claims.
