U.S. patent number 3,901,527 [Application Number 05/449,481] was granted by the patent office on 1975-08-26 for wheel chair with extensible wheel base to facilitate ingress and egress.
Invention is credited to Reuven Danziger, Uzi Danziger.
United States Patent |
3,901,527 |
Danziger , et al. |
August 26, 1975 |
Wheel chair with extensible wheel base to facilitate ingress and
egress
Abstract
According to the invention, there is provided a wheelchair
having a propelling wheel, the said wheel being held in a wheel
holder which in turn is mounted both pivotally and slidingly from a
first forward position to a second backward position with respect
to the seat and backrest of the wheelchair, a lock means being
provided which is adapted to lock the said wheel holder in either
of the said extreme positions.
Inventors: |
Danziger; Uzi (Netanya,
IL), Danziger; Reuven (Netanya, IL) |
Family
ID: |
11047000 |
Appl.
No.: |
05/449,481 |
Filed: |
March 8, 1974 |
Foreign Application Priority Data
Current U.S.
Class: |
280/638;
280/250.1; 280/211; 280/650; 297/411.34 |
Current CPC
Class: |
A61G
5/125 (20161101); A61G 5/00 (20130101); A61G
2200/34 (20130101); A61G 7/103 (20130101); A61G
5/10 (20130101); A61G 7/10 (20130101); A61G
7/1046 (20130101) |
Current International
Class: |
A61G
5/00 (20060101); A61G 5/12 (20060101); A61G
5/10 (20060101); A61G 7/10 (20060101); A16G
005/00 () |
Field of
Search: |
;280/242WC,242R,211,289,34C ;297/417,DIG.4,DIG.10 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Friaglia; Leo
Attorney, Agent or Firm: Browdy and Neimark
Claims
What is claimed is:
1. A wheelchair comprising:
a chassis;
a seat for a rider, mounted on said chassis;
first and second rear propelling wheels disposed on opposite sides
of said chassis;
a wheel hub, having mounted thereon one of said rear propelling
wheels;
a pivot arm pivotably connecting said wheel hub to said chassis at
a fixed pivot point thereon;
an arcuate guide connected to said wheel hub and slideably engaging
said chassis at a point on said chassis above said pivot point,
said arcuate guide defining an arcuate path of said wheel hub about
said pivot point between two opposite end positions of said arcuate
guide;
said pivot point being positioned on said chassis at a point
substantially vertically below a midpoint along said arcuate path
between the two opposite end positions; and
hub locking means for locking said wheel hub in either of the two
end positions of the arcuate path.
2. A wheel chair according to claim 1, further including:
a second wheel hub having mounted thereon the other of said rear
propelling wheels;
a second pivot axis pivotably connecting said second wheel hub to
said chassis at a second fixed pivot point thereon;
a second arcuate guide connected to said second wheel hub and
slideably engaging said chassis at a point on said chassis above
said second pivot point, said second arcuate guide defining an
arcuate path of said second wheel hub about said second pivot point
between two opposite end positions of said second arcuate
guide;
said second pivot point being positioned on said chassis at a point
substantially vertically below a midpoint along said arcuate path
of said second wheel hub between the two opposite end positions;
and
second means for locking said second wheel hub in either of the two
end positions of the arcuate path thereof.
3. A wheelchair according to claim 1, further including:
first and second armrests attached to opposite sides of said
chassis;
a rigid plane surface disposed on one of said armrests on the side
thereof facing said seat, said one of said armrests being hinged to
said chassis to be swingable from a vertical position to a
horizontal position; and
armrest locking means being provided for securing said armrest in
either the vertical or horizontal position thereof;
said pivot point being disposed and said pivot arm and said arcuate
guide being of such size that when said wheel hub is in one of the
end positions of the arcuate path, said armrest is swingable into
the horizontal position thereof in a plane below the uppermost
vertical extention of said one of said rear propelling wheels
without contacting said one of said rear propelling wheels.
4. A wheelchair according to claim 2, further including:
first and second armrests attached to opposite sides of said
chassis;
first and second rigid plane surfaces disposed on respective ones
of said armrests on the sides thereof facing said seat, each of
said armrests being hinged to said chassis to be swingable from a
vertical position to a horizontal position; and
first and second armrest locking means being provided for securing
respective ones of said armrests in either the vertical or
horizontal positions thereof;
said pivot points being so disposed and said pivot arms and said
arcuate guides being of such size that when respective ones of said
wheel hubs are in one of the end positions of the respective
arcuate paths, the respective ones of said armrests are swingable
into the horizontal positions thereof in planes below the uppermost
vertical extensions of the respective ones of said rear propelling
wheels, without contacting the respective ones of said rear
propelling wheels.
Description
BACKGROUND OF INVENTION
The present invention relates to a wheelchair, in particular to a
wheelchair having two rear propelling wheels and either two
detachable or folding armrests or only one such armrest, while the
second remains fixed.
The invention is especially, but not exclusively, useful with
respect to wheelchair constructions for the kind of user who is
capable of propelling the said wheelchair manually by rotating the
wheels with his hands but has great difficulty in transferring
himself to another chair, car or bed, and due to the weakness of
limbs is unable to stand up or sufficiently raise his torso.
The advantage of such manually operated wheelchairs resides in its
allowing the user a maximum of independent mobility, as can be
expected under such circumstances.
The disadvantage of such manually operated wheelchairs for said
kind of user is that due to the fact that the propelling wheel does
not permit the user to slide across the wheelchair, which prevents
the user of the chair from moving in a lateral direction.
The object of the present invention is to provide a manually
operated wheelchair which is designed to overcome the
aforementioned problem.
SUMMARY OF INVENTION
In the following description the said "first" position will be
referred to as "transporting position," since in that position the
wheelchair can be used to transport its rider from one place to
another. The said "second" position will be referred to as
"transferring position," since in it, the rider can transfer
himself from the wheelchair to another means of support, say
another chair, the bed or the like.
In a practical embodiment of the invention, the holder comprises an
arcuate guide which is pivotally attached to the rear of the
chassis of the wheelchair and which is slidingly displaceable in
relation to the said chassis, the said propelling wheel being
rotatably attached to the wheel holder and an operating
pulling-pushing handle being provided for moving the wheel holder
and the propelling wheel between said extreme positions.
According to a further feature of the invention, the said lock is
comprised of a hinge pivotally connecting the lock to the
wheelchair body, a latch locking said wheel holder in either of its
extreme positions, and an operation release handle for releasing
said wheel holder from the catch of the latch.
Since the novel wheelchair is opened in its transferring position
on the seat side by locating the propelling wheel at the rear of
the seat, it is possible to provide a convertible armrest which is
transformed into a sliding board by pivoting the armrest to the
horizontal position.
According to this feature of the invention the convertible armrest
has a rigid plane surface on its inner side and hinges on its seat
level so as to be adapted to be swung from the vertical armrest
position to the horizontal sliding position, a lock being provided
for locking it at its armresting position.
This part of the invention makes unnecessary the use of a special
additional sliding board separate from the wheelchair, and is
intended for use by the invalid rider of the wheelchair, enabling
that person to slide from the chair onto another support.
Further features and advantages of the invention will be apparent
from the description below.
SHORT DESCRIPTION OF DRAWINGS
The invention is herein described with reference to the
accompanying drawings which illustrate, for purposes of example
only, one form of wheelchair constructed in accordance with the
invention.
In the drawings:
FIG. 1 is an elevational side view illustrating such a wheelchair
while its propelling wheel is locked in the transporting
position.
FIG. 2 is a like view illustrating the propelling wheel in a
position intermediate the two extreme positions.
FIG. 3 is another elevational view illustrating the wheel in the
backward locked transferring position, and the construction of the
convertible armrest.
FIG. 4 is a fractional perspective view illustrating the
construction and operation of the wheel locating arrangement while
it is in the midposition.
FIG. 5 is a partial perspective view illustrating the wheelchair in
its transferring position, with the wheel locked in its backward
location and the armrest converted to its horizontal sliding
position.
FIG. 6 is a fractional perspective view illustrating the
construction of the armrest pivoting and mounting arrangement.
FIG. 7 is a perspective view illustrating the embodiment of
wheelchair in which both rear wheels and both armrests are
pivotable.
DESCRIPTION OF PREFERRED EMBODIMENT
The wheel holder designated as a whole by the numeral 1 is
comprised of a tubular member 2 (see FIG. 4), a fork 3 carried by
the tubular member 2 and connected to it as by welding, having
drilled holes 4 at its lower end. At its upper end the tubular
member 2 carries a hollow cross piece 5, as by welding. Cross piece
5 carries on its inner end i.e., that side which faces the
wheelchair, e.g. by having welded to it, an arcuate guide rail 6
shaped of flat metal and being curved with holes 4 as centre,
handle 7 is affixed to cross piece 5, e.g. being welded to it, on
its upper side. The handle 7 includes a padded grip 8 on its upper
end (see FIGS. 1 and 2). An ear or bracket 14 is carried on the
rearwardly extending bar 15, forming part of the chassis being
affixed by shackles 17.
The fork 3 rides on the bar 15, a pin 16 passes through holes 4 and
the bracket 14. The arcuate guide 6 is slidingly connected to the
chassis by means of a bolt 18 which passes through a spigot 19
extending from the chassis. The guide 6 is positioned on the inner
side with respect to the wheelchair body.
Said wheel holder 1 is mounted swingingly on the wheelchair body,
and therefore by pushing and pulling said handle 7, the wheel
holder 1 moves about its centre 4, its arcuate guide 6 sliding on
body pivot 19 along its arcuate slot 9 between the closed ends 10
and 11 of the slot 9, its movement being limited by the bolt 18.
The propelling wheel 20 being carried on the cross piece 5 by a pin
22 which passes also through the wheel hub 21, can be moved
backward and forward between its two extreme positions carried by
the wheel holder 1.
For the purpose of locking the wheel 20 in either of its said
extreme positions a wheel lock is provided.
The wheel lock 23 comprises a pawl 24 connected by a curved arm 24'
to an eye 25. From arm 24' extends releasing handle 26.
The handle bar 26 has a padded grip 27 on its free end. The lock 23
is mounted pivotally by means of the eye 25 on the spigot 19
opposite the arcuate guide 6 and is joined together with the guide
6 by the bolt 18.
While the propelling wheel 20 is in its forward transporting
position, pawl 24 is engaged in an appropriate catch 12 on the rear
part of the arcuate guide 6 holding the wheel 20 in said position.
Respectively, when wheel 20 is in its backward transferring
position, pawl 24 engages over the front end 13 of the arcuate
guide 6.
As can be learned from FIGS. 1 and 3, while the propelling wheel 20
is in either of its extreme positions, the wheel holder member 2 is
inclined about 30.degree. in a forward direction or a backward
direction relative to the vertical. Therefore when releasing handle
26 is lifted from either engaged position, member 2 assumes a
vertical position due to the force generated by the weight of the
wheelchair body and the user. While member 2 is in the vertical
position, wheel 20 is in the midway position between its two
extremes. On the other hand, when the wheel locating handle 7 is
either pushed or pulled from its midway position toward one of its
extreme positions, the locking pawl 24 is engaged by the
appropriate catch, either 12 or 13, by the force of the weight of
the releasing handle 26 as suggested in FIGS. 1, 2 and 3.
These two features of the invention discussed above, i.e., the
gravitationally self changing propelling wheel being moved to the
half way position by only lifting the releasing handle 26, and the
gravitationally self locking of the latch 24 being achieved by only
pulling or pushing the wheel locating handle 7 to desired position,
simplify the construction of the wheelchair according to the
invention without special need for springs or other problematic
mechanisms, and which is even more important -- these features
enable the user to operate the wheel location by two simple
movements of one hand, as described above.
The convertible armrest indicated as a whole by the numeral 30
comprises a tubular bent frame 31 carrying on its inwardly facing
side, (in respect to the seat 28), a plane surfaced rigid sheet 32,
of metal or hard plastic. The frame 31 is provided at its lower
corners 33 and 34 with two hinge members 36 and 37 of any known
kind co-operating with two corresponding hinge members 38 and 39
provided on two tubular members 40 and 41, which are mounted
adjustably and detachably by means of two bolts 42 and 43 in two
sleeves 45 and 46 carried on the wheelchair body e.g. being welded
thereto. A spring operated lock 50 positioned on the chassis, in
register with point 43 secures the rear upper corner of the armrest
30 in its vertical armresting position.
The members 40 and 41 have a plurality of adjustment holes 44 (see
FIG. 7) and the sleeves 45 and 46 have, respectively, one
corresponding hole 47 and 48. While armrest 30 is in its horizontal
sliding position, the sliding surface 32 has to be on the same
level with the sitting plane which is not always identical with the
wheelchair seat surface 28, because some users employ seat cushions
to prevent decubitus ulcers. The plurality of holes 44 enables the
selection of the appropriate surface level of the armrest sheet
32.
The mode of operation of the novel wheelchair will be apparent from
the following description.
Transfer of wheelchair rider to another (stationary) seat
The wheelchair is in transporting position occupied by the user
preparing to transfer himself to another seat. The wheelchair is
brought near the desired stationary seat. The user, or his
assistant, lifts the releasing handle 26 whereupon the propelling
wheel 20 drops to the midposition, the operator then pushes back
the wheelplacing handle 7 until the releasing handle 26 falls into
its lower position signifying that the pawl 24 is in engaging
position i.e., the wheel 20 is locked in its backward position
behind seat 28 and backrest 29. Then the operator releases the
armrest 30 from its vertical closed position, the operator pivots
the armrest 30 to the horizontal position until it rests on the
edge of the desired seat. The wheelchair is then prepared for
transferring.
Transfer from a stationary seat onto the wheelchair
The wheelchair is unoccupied and a user is preparing to transfer
himself onto the wheelchair. The wheelchair is brought to
transferring position in the same way as described above and, after
the transferring operation is completed, the operator pivots the
armrest 30 to its vertical position until the armrest 30 is engaged
by the lock 50. Then the operator lifts the releasing handle 26,
the propelling wheel 20 drops to its midposition, wheel locating
handle 7 is pulled forward by the operator until the releasing
handle 26 drops to its lower position signifying that the pawl 24
is engaged i.e. the wheel 20 is locked in its forward position, and
the wheelchair is ready in its transporting position.
It will be appreciated that the above described construction could
be used in part only, for example, without the convertible armrest
but with a conventional detachable armrest, or with a convertible
armrest provided to fit a so-called "car transit chair," i.e., a
wheelchair having small wheels only, and intended for operation by
an assistant. It will also be appreciated that characteristic parts
of the above described invention could be mounted on a conventional
wheelchair even by the consumer, since these parts could be
prepared for fitting those wheelchairs, without disturbing their
positive properties, e.g. their collapsibility or stability. These
aforementioned variant applications may be made within the scope of
the invention as defined in the following claims.
Many other changes, variations and applications of the illustrated
embodiment may be made within the scope of the invention, as
defined in the following claims.
* * * * *