Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
- ~Zl~;9(~7
,
~LEVATOR DEVICE FOR WHE~LCHAIR AND ~HEELC~LAIR INCORPORATING SA~.
The i vention rclates to ~he~lcilairs llsed by handicapp~d persons
and invalids and is equally well applicabJe to folding or non-folding wheeJchair~.
It is an incontestablc fact that whcelchairs have given handicapped
persons and invalids the possibility of rnobility. HoweYer~ these whee~chairs
5 pres~nt several drawbacks due to the users being able ~o occupy only one
sitting position in ~hich they generally remain ~or relatively long periods
of Time.
Firstly the solc sitting position ~ hich r~lay be adopted does not allow
readap~ation to norn-al living conditions and do~s not laciJita~e social con~acts.
Sccondly this sitting position mainTained fo. long periods of timc
is responsible lor physical degradation such as loss of an~ular amplitude of
the louer limbs poor blood circulation slo~ing down of the diges~ive and
intes~inal functions. fragiJity of the bones etc
In an at~en~pt to overcome the above drawbacks different propcsitions
have already been put forward.
A first proposition has been to provide the irame of a wheeJchair
with an articulated struct-;re comprising a back a seat and a footres~. Such
a structure is mounted to pivot by the s~at on a fronl horizontaJ axis perpendi-cular tc the vertical plane of symmctry o~ the Irame. In such an embc-dir.qent
a jack incorporating an electric motor is interposed bet heen the IralTIe and
the structurc and more general~!. tl e seat so as to be ab~e to contro~ the
raising or lo~ering o~ tl~e articulat~d structure.
Such a solution invo3ves a sourc~ of energy borne by the wh~elchair
and poses problems of safety reliabili~y price and weight by reason of the
use o~ electrical encrgy. These different problems render practical application
difficult if not impossiblc.
Another proposition has been to mount on the frame of a wheelchair
a seat plvoting on a iront horizontal axis. A hydraulic pump controlled manual-
ly suppli~s a hydraulic jack interposed between 5uch a seat and the ~ramc.
Such a solution is in fact of intcrest onl~ hen a handicapped person
usin~ a supporting appliance o~ the orthosis Iype is to be transferred from
a sit~inK position lto a standing position and vice versa. Such a solution thcrefore
cannot solve the problem raised that of o~fcring the possibility for a handi-
cappcd person to occupy a sittin~ position or a stable pseudo-vertical position
in complete safety.
l~S~1~7
--2-
A third known solution has been to propose the adaptation on the
two Jateral sides of a wheelchair oI two articulated systems fixed to the
pivoting armre~ts. A1eans are provided ~or maintainin~ the two systems laterallyand to the rear when the ~-~heelchair is used normally. The means provkled
5 are also ~esi~ned so as to allow the two ar~iculated systems to be ~olded
down forwardJy, in which case they may be connected by a front bar on ~hich
the patient may exert a traction b~ his arms to find assistance ~or rising.
The tw.o articulaoed s!sterrls are ~enerally designed ~o ~orm a sort
of cage, in association with the front bar, such a cage bein~ compJeted by
10 the existance oI pivoting stops which may represent a back or bottom support
~or the pa~ien~ occupying the slanding position.
Such a soJution seems to respond to the general problem posed, but
leads to a device which is long to piace in position or possibly to retract
after use. In addition, such a device is little used in practice as it does not
15 offer the pati~nt the possibility o~ making frequent transitions ~rom sittin~position to standing position, and vice versa, rapidly, easily and without ~reatfatigue.
Fur~herm~re, ~he ~echnica1 means retained form a cumbersorne assem-
bly rendering the wheelchair unusable in nurnerous practical cases, whenever
20 the ground surface s3r the volume of aecess is reduced.
Moreover, such a system can really be used only by a handicapped
person or invalid capa~le of developing considerable muscular work and o~
finding a possibili~y of blocking the joints whcn the standing posision has
been at~ained.
It is an objec~ oJ ~he invention to provide a real, practical solution
~o the problem se~ ~orth abovc, by proposin~ a simpJe~ robust, adjustable deviceoffering certain security and reliability, even when subjected to intensive
use.
The objec~ of the inven~ion is designed so as to ~limina~e any auxiliary
30 or additional energy supply and to be 2ble to be used vir~ualJy by any handi-capped person, whatcver his age and the physical power that he can develop.
It is another c~hject of the invcntion to offer means of small dimensions
which rnay be provided at rnanu~acture on wheelchairs especially designed
to this end or adapted to equip whcelchairs of conventional design, whether
35 such whcelchairs are of rigid or foldable structure.
15.~'7
-3-
lt is a further object of the invention IO propose a novel device for
adjusting, with precision, the different parameters having to be considered
to effect transition from the sitting position to the standing position, taking
into account the mor'phology, si~e and weight of each patient.
To attain the objectives set forth her'einabove, the object of the
invention is characteri7ed in that it is in the form of an articulated structureconstituted b~ two articulated s)~stems symmetrical with respect to a vertical
plane of symmetry, intcncled to be adapted laterally on tl-e frame o~ a wheel-
chair and connected together by a back, a seat and a footrest, each articulated
system comprising:
- a first deformable quadrilateral ;ntended to be mounted pivotally
on the substantiallv front part of a wheelchair frame corresponding to the
seat in order to contribute IO the support of a seat,
- a second deformable quadrilateral articulated part!y on the first
and partly on the frame in order to contribute to the support of a footrest,
- a trilateral articulated on the first quadrilateral opposite the second
in order to contribute to the support o~ a back,
- an elastic member adapted to be interposed between the first quadri-
Iateral and the frame,
- and a manoeuvring assembly adapted to be disposed between the
first quadrilateral and the frame in order to perform a function of manual
control and monitoring of the relative pivoting of said system with respect
to the frame and a function of stop and locking of said system in a lowered
or elevated position of the structure.
The invention also relates to a wheelchair comprising an elevator
device according to the invention.
The invention will be more readily understood on reading Ihe fol!owing
description with reference to the accompanying drawings, in which:
Fig. I is a side elevation schematically showing a wheelchair for
30 a handicapped person or invalid, equipped with a device accorciing to the inven-
tion.
Fig. 2 is a front view, on a different scale, taken along Jine 11-11
of ~ig. 1.
Fig. 3 is a schematic view, similar to FiK. 1, but illustrating a second
35 position characteristic of a wheelchair incorporating the device of the invention.
D7
Fig. 4 is a schernatic view showing a variant embodiment of one
of the elements constituting the object of the invention.
Referring no ~ to the drawin~s, Figs. I and 2 schematicalJy show
a wheelchair I comprisin~ a frame 2 constituted by front uprights 3 and rear
5 uprights 4 connected together by sills 5 and crosspieces 6. These different
constituent elements define a seat bearin~ reinforcement 7 and a back bearing
reinforcement 8 in the upper part of which handles 9 may be provided to
facilitate displacement of the wheelchair for a person assistin~ the handicappedperson.
The frame 2 is provided, in manr:er known per se, with bearing and
driving wheels 10 and with swivelling guidin~ wheels 11.
The above frame 2 corresponds to a wheelchair of rigid design, but
it is obvious that a substantially similar form is retained for a foldable wheel-
chair. In Iact, in such a case~ the rigid elements forming the crosspieces
15 6 are replaced by folding elements of design known per se.
The above-described frarne 2 is equipped, accordin~ to the invention,
with an elevator de ice in the form of an articulated structure 12 borne by
the frame 2. The articulated structure is constituted by two articulated systems13 symmetrical with respec~ to a vertical plane of symmetry P of the wheel-
20 chair or the bearing frame 2. Each articulated system 13 is intended to beadapted laterally on the frame 2 and is connected to the homologous system
13 by a back element 14, seat elementl5 and.footrest element 16. These differentelements are, in the example illustrated, formed by rigid structures, but it
is obvious that a different embodiment may be adopted in the event of such
25 elements also having to comply with the imperalive of folding in concomitance with such possibility offered by the bearin ~ frame 2.
Each articulated s)stem 13 comprises a first deformable t1uad ilateral
17 constituted by t~!o bars 18 and 19 joined at their ends located near the
back reinforcement ~, by a spacer bar 20. The quadrilateral 17 is adapted
30 to be disposed laterally, for example outside the corresponding lateral side
of the frame 2, so that the bars 18 and 19 are substantially superposed.
The quadrilateral 17 is mounted on the seat reinforcement 7 by a
first point of articulation 21 provided between the front free end of the lower
bar 19 and, for example, the upper sill 5. A second point of articulation 22
35 is provided between the upper bar 18 and the seat reinforcement 7, so that
~s~0~
--5--
the geometrical axis of this point is substantially located in upper front position
of said reinforcement 7. In the example illustrated the point of articulation
22 is borne by an ex~ension 23 formed by the corresponding front upright
3. In the case illustrated the distance separating tl-e points of articulation
21 and Z2 and that between the points 24 and 25 joining the bar 20 to the
bars 1~ and 19 are equal and giv~ ~he quadrilateral 17 a privileged form of
parallelogram.
A desired deforrnation of such a quadrilatera) may be envisaged with
a view to adapting its characteristics as a function of the morphology of
the patients. 1n this respect it may be provided to render the point of articula-
tion 21 adjustable forwardly or rearwardly in the horizontal plane of the bearing
Irame 2.
Each articulated system 13 further cornprises a second deformable
quadrilateral 26 which is disposed on the frame 2 substantially in front of
the seat reinforcement 7. Quadrilateral 26 comprises a jamb 27 connected
by a point of articulation 2S to an e~tension 29 of the bar 18 be~ond the point
of articulation 22. The extension 29 constitutes one of the sides of the quadri-lateral 26. The jamb 27 is joined to the corresponding front upright 3 by a
spacer bar 30 articulated on points 31 and 32. The spacer bar 30 represents
the third side of quadrilateral 26 of which the fourth is formed by that part
of the upright 3 included bet een points of articulation 22 and 32.
The jamb 27 extends substantially belov the point of articulation
31 and supports a footrest 33 in cooperation ~ ith the jamb 27 of the homologousarticulated system. Although this has not been sho vn the means for connection
between the footrest 33 and the jamb 27 are provided to allow adjustment
in height and re ative orienlation.
The point of articulation 2~ is preferably adjustable so ~hat the practi-
cal length of the extension Z9 can be modified and the inclination Gf the
jamb 27 can be adapted as a function of the patient s morphology.
Each articulated system 13 further comprises an articulated trilateral
34 constituted by an upright 35 mounted pi~otally on pin 24. Trilateral 34
is composed of upright 35 the spacer bar 20 and a triangulation bar 36 articula-ted on the one hand on pin 25 and on the other hand on a pin 27 borne by
the upright 35. The position of pin 37 on the upright 35 is preferably adjustable
so as to allow possible adiustment o~ the angle formed by the upright with
- \
~2~LS~9
-b-
respect to the bar 18.
Each articulated systern 13 also comprises an elastic member 38
interposed between the deIormable quadrilateral 17 and the Irame 2. The
elastic member 38 is interposed between the upper bar 1~ and the lower sill
5 5, being adapted on these elernents by points of articulation 39 and 40 which
are preferably adjustable in position forwardly or rearwardly of the frame
2~ The elastic member 38 is designed to perform a function of compensation
of ueight and energv absorption. as well as a function of restitution, as ~
appear hereinafter. The elastic member 38 may be constituted by a compensa-
lO ting spring or, preferably according to the invention, bv a jack of the gasactuated type, advantageously provided with a valve for adjusting the transler
of its fluid. Fig. 2 shows that the elastic member 38 is preferably placed
inside the seat reinforcement 7 of the frame 2.
Each ar~iculated system 13 further comprises a manoeuvring member
15 41 intended to perform a function of manual controJ of the relative pivoting
of the articulated system 13 with respect to the frame and a function of
stop and locking of said system in a position of maximum lowering correspon-
ding to the sitting position, as shown in Fig. 1, or in a position of elevation
as will follow from the following. To this end, the manoeuvring assembly
20 41 comprises a lever 42 mounted pivotally by a point 43 on the first quadrilate-
ral 17 and preferably on the upper bar 18. The lever 42 is extended by an
angle arm 44 extending towards the front part of the frame 2 and joined
by an articulation 45 to a connecting rod 46 mounted by a point oi articulation
47 on the frame 2. The elements constituting the assembly 41 are disposed
25 laterally and externally with respect to the articulatcd system 13, as shoun
in Fig. 2.
~ ig. I shows that the assembly 41 is designed so that, in a position
of ma~imum lowering corresponding substar)tially to tl-e sitting position, the
pivot pin 43 is disposed below the fic~itious line passing through the points
30 of articulation 45 and 47. This results in a geometrical locking which opposes
any untimely pivoting of the lever 42 in the direction of arrow fl. The functionof locking is completed by a function of stop determining the sitting position.
This stop function is for example performed by a catch 48 or the like borne
by the arm 44 and under which the connecting rod 46 abuts in the position
35 illustrated in the drawing. This stop rnay be principal or preferably secondary,
intervening in combination with a damper placecl between the quadrilateral
17 and the seat reinforcement 7.
As stated previously, the two articulated systems 13 ;~re connected
by back, seat and footrest elements which are designed to establish a conjuga-
5 tion of their relative displacement and form therewith the articulated structure12.
In the state illustrated in Fig. 1, the structure 12 occupies a position
of maximum lowering with stop and locking and the wheelchair then performs
the function of seat for a patient occupying the seat, back and footrest. In
' this position, the elastic members 38 are compressed.
When the patient wishes to be transferred from sitting position to
a pseudo-vertica! position, he acts on levers 42, pivoting them in the directionof arrow fl, so as to pass the points of articulation 43 beyond the alignment
of points 45 and 47 and thus to break the lateral geometrical lockings esta-
15 blished by the assemblies 41. The levers 42 rnay thus pivot on points 43, abuttingby points 45 on the connectin~ rods 46. This results in the combined elevation
of points 43 which controls pivoting of the quadrilaterals 17 in the direction
of arrow f2 on points 21-22. This pivoting, once started by action on levers
42, is taken over, assisted or maintained, depending on the adjustments made,
20 by the elastic members 38 which restitute the energy previously stored.
In this way, the patient is progressively raised by the pivoting of
the quadrilaterals 17 of the articulated systems 13, whilst having the possibility
of controlling this pivoting movement by a retaining action on the levers
42, insofar as the action of restitution of the elastic members 35 is sufficient25 to take over pivoting of the structure 12 after unlocking by manual action
on the levers 42.
By the pivoting of the deformable quadrilaterals J7, the trilaterals
34 are raised and maintain the uprights 35 substantially in their initial orienta-
tion. This results in a pro~ressive opening of the angle formed between thc
30 seat and back planes.
Simultaneously, the downward pivoting of the extensions 29 subjects
the quadrilaterals 26 to a corresponding deformation tencling to lower the
~s~
--8--
footrese 33. The jambs 27 are of such iength that, as a function of the adjust-
men~ made to point 28, they abut on the ~round when the structure 12 occupies
the position of maximum eJevation shown in Fig. 3. This position is attained,
determined and locked via the two assemblies 41. In fact, the relative pivoting
5 in the direction of arrow fl of the levers 42 and the corresponding relative
pivoting of the two quadrilaterals 17 have for their effect to bring points
45 beyond the alignment of the points of articulation 43.
This results in a geometrical locking in a stable position of elevation,
determined by the abutment of arms 44 against stops 49 borne for example
10 by the lower bars 19 of the deformable quadrilaterals 17.
The above means consequently make it possible to maintain the struc-
ture 12 in a position of elevation, as illustrated in Fig. 3, in which it represents
a continuous plane of support and hold for a patient maintained in a virtually
s~anding posture, bearing by his feet on the footrest 33.
IS Stable restraint of the patient may be ensured if necessary by straps
passing around the legs and the torso.
When the patient wishes to control the reverse transition towards
~he stable sitting position, he acts on levers 42 in the direction of arrow f3
so as to break the geometrical lock allowing rotation of the levers on the
20 points of articulation 43. By effect of traction exerted on the connecting
rods 469 the rotation of levers 42 is translated by a pivoting of the two defor-mable parallelograms 17 in the direction of arrow f4 and by a concomitant
displacement of the quadrilaterals 26 and the trilaterals 34.
When this movement is started, the weigh~ of the reinforcerr,er t
25 12 and of the patient is responsible for the compression of the springs 3~
which store the restitution energy as the articulated structure 12 pivots in
return towards its lower position.
The elastic membcrs 38 are provided to offer a certain resistance
to such a cornpression, so as to effect a compensation of the weights supported
30 and to avoid a rapid return to the stable position of rnaximum lowering. As
before, levers 42 make it possible to control, if necessary, the pivoting of
structure 12 towards this position of maximum lowering.
Adjustment of the relative position and of the reaction of compression
opposed by the elastic members 38 are in practice determined so as to obtain,
35 for a patient of given weight, a slow, progressive return from the position
.
L$~
g
of ma~imum elevation to the position of maximum iowering. In such a case
of adjustment, the reverse pivoting involves a weak but constant ac~ion on
~he levers 42 so as to apply an additional force capable of overcorning the
frictions created by the pivoting of the different elements constit~lting the
5 articulated structure 12 and of being added to the work of the elastic members 38.
As is seen from the foregoing, the means according to the invention
are simple, inexpensive, reliable and robust and make it possible, withou-t
additional outside energy, to control a transfer from a position of maximum
10 lowering to a position of maximum elevation, and vice versa, of the articulated
structure i2 ensuring either the support of a patient in sitting position, or
the maintenance of the patient In a virtually standin~ posture.
The means of the invention offer noteworthy stability in the position
of maximum elevation, since the articulated structure 12, in extended position,
15 finds additional support on the ground via the jambs 27 which increase the
bearin~ surface determined by the points of contact between the ground S
and the wheels 10 and 11.
It should be noted that the particular form of the manoeuvring assem-
blies 41 is also chosen so ~hat the levers 42 represent, in the position of maxi-
20 mum elevation, as illustrated in Fig. 3, lateral elements capable of contributingto a transverse wed~ing of the patient's body, if necessary.
In cer~ain cases, each manoeuvring assembly 41 may be provided
with means for multiplying the amplitude of displacement, so as to reduce
the amplitude of pivoting of lever 42. In that case, each assembly 41 comprises,25 as illustrated in Fi~. 49 a lever 42a articulated directly by point 43a on the
deformable quadrilateral 17. Lever 42a is associated by a point of articulation
50 with an arm 51 which is articulated by a point 52 on a crank 53 itself
articulated on a point 54 borne by the deformable quadrilateral 17. The end
o~ crank 53, opposite the point of articulation 54, is joined by an articulation30 55 ~o connecting rod 46a.
Assemblies 41a function in similar manner to what is described above
and perform the same functions for a lower amplitude of angular pivoting
of the levers 42a.
The means of the invention make it possible to effect a rapid transfer
35 of position~ without using a great deal of physical energy, and may thus be
- \
~2~
--lo-
used relatively frequently by a patient wishing to adopt ~n upright position
to facilitate his general activity and for carrying out ordinary tasks, or wishing
to change his position so as to favour maintaining more suitable physical
conditions.
S Another advantage of the object of the invention lies in the fact
that the means used are of particularly small dimensions and are included
within the maximum volume of an ordinary wheelchair.
Another important advantage of the object of the invention lies
in the fact tha~ the technical means recommended make it possible to consti-
10 tute an elevator device representing a structure easily adapted on a wheelchair
of ordinary type, on the frame of which the necessary points of articulation
are added.
It thus becomes possible to envisage marketin~ the elevator device
alone and to fit it on wheelchairs of conventional design, or to envisage produ-
~5 cing wheelchairs fitted at manufacture with a device according to the inven~ion.
In ~his respect, the invention therefore relates to an elevator deviceIn the genera3 sense and to a wheelchair, of any design, comprising such a
device.
Another important advanta~e of the invention resides in that the
20 physical energy spent by the action of the arms on the levers 42 may be re-
duced by using to advanta~e the action of the body and, more particular~y,
of the torso on the back part of the structure 12. In fact, insofar as a strap
connects the patient's torso to the back, a thrust action in the direction of
arrow fS (Fig. I) has for its effect to stress the trilaterals 34 which then
25 tend to provoke pivoting of the quadrilaterals 17 in the direction o~ arrow
f2. Such an action therefore contributes to reducin~ the force exerted on
the levers 42~
A traction exerted in the direction of arrow f6, from the position
according to Fig. 3, produces a similar aid for returnin~ the structure 12 into
30 sitting positionO
The invention is not limited to the examples described and shown,
as various modifications may be made thereto without departin~ from the
scope thereof.
