FR2529456A1 - Elevating device for a wheelchair and wheelchair making use thereof - Google Patents

Abstract

Assistance for the handicapped. The device is made in the form of an articulated structure 12 comprising two lateral symmetric systems 13 each comprising a first deformable quadrilateral 17, a second deformable quadrilateral 26, a trilateral polygon 34, an elastic member 38 and a handling unit 41. Application to wheelchairs for the handicapped.

Description

 The present invention relates to wheelchairs used by the disabled and the disabled and refers, indif fervently folding wheelchairs or not.

It is undeniable that wheelchairs have brought a possibility of mobility to disabled and disabled,
These wheelchairs, however, have several disadvantages that users can only occupy a sitting position, otherwise maintained in general for relatively long periods.

 In the first place, the only sitting position that could be adopted does not permit a re-adaptation to everyday life and does not facilitate social contacts.

 Secondly, this sitting position maintained for long periods of time is responsible for physical deterioration such as loss of angular amplitude of the lower limbs, defective blood circulation, slowing of the digestive and intestinal functions, bone fragility, etc.

 In an attempt to overcome the above disadvantages, various proposals have already been made.

 A first proposal was to have the frame of a wheelchair carry an articulated structure comprising a backrest, a seat and a footrest. Such a structure is mounted articulated by the seat on a horizontal front axis, perpendicular to the vertical plane of symmetry of the frame. In such an embodiment, an electric motor cylinder is interposed between the frame and the structure and, more generally, the seat, so as to be able to control the raising or lowering of the articulated structure.

 Such a solution involves a source of energy and raises problems of safety, reliability, price and weight, related to the implementation of electrical energy. These different problems make the practical application difficult, if not impossible.

 Another proposal was to mount on the chassis of a wheelchair a swivel seat on a horizontal front axis. A hydraulic pump, controlled by hand, is responsible for supplying a hydraulic cylinder interposed between such a seat and the frame.

 Such a solution is, in fact, of interest only in the case where it is appropriate to transfer from the seated position to the standing position and vice versa a handicapped subject wearing an assistive device of the orthosis type. Such a solution is therefore not capable of solving the problem posed of offering a possibility of occupying a disabled subject with a sitting position or a stable pseudo-vertical position in complete safety.

 A third known solution has been to propose the adaptation on both lateral sides of a wheelchair of two articulated systems fixed to the pivoting armrests. Means are provided to hold the two systems laterally and rearward in the case of routine use of the chair. The means provided are also designed to allow the forward folding of the two articulated systems which can then be connected by a frontal bar on which the subject can exert traction by the arms to find assistance to the elevation.

 The two articulated systems are generally designed to thus form a kind of cage, in association with the frontal bar, such a cage being completed by the existence of pivoting stops that can represent a dorsal or gluteal support for the subject occupying the standing position .

 Such a solution seems to answer the general problem posed, but leads to a long device S put in place or possibly to retract after use. In addition, the practical implementation of such a device is low, since it does not offer the subject the possibility of achieving quickly, easily and without great fatigue, frequent transitions from sitting to standing and vice versa.

 Moreover, the technical means selected form a bulky assembly making the chair unusable in many practical cases, whenever the floor space or the access volume is reduced.

 In addition, such a system can be validly used only by a disabled or disabled subject, capable of developing significant muscular work and to find a possibility of articular blockage when the transfer in positiondebout has been reached.

 The object of the invention is to provide a real practical solution to the problem above, by proposing a simple device, robust, adjustable, offering some security and reliability, even in case of intensive use.

 The object of the invention is designed in such a way as to eliminate any auxiliary or additional energy supply and to be able to be practically implemented by any handicapped person, whatever his age and the physical power he is able to develop. .

 Another object of the invention is to provide space-saving means that can be provided in the first assembly or manufacture on armchairs specially designed for this purpose or adapted to equip-armchairs of traditional design, that these chairs are indifferently rigid structure or foldable structure.

 An additional object of the invention is to propose a new device for adjusting, with precision, the various parameters to be considered to achieve the transition from sitting to standing, taking into account the morphology, the size and the weight of each subject.

To achieve the above aims, the object of the invention is characterized in that it is embodied in the form of an articulated structure constituted by two articulated systems symmetrical with respect to a vertical plane of symmetry, intended to be adapted laterally on the chassis of an armchair and joined together by a backrest, a seat and a footrest, each articulated system comprising
a first deformable quadrilateral for
be hinged on the part substantially
front of an armchair chassis correspon
sitting to contribute to the support of a
seated,
a second deformable quadrilateral articulated in
part on the first and partly on the chaps
sis to contribute to the support of a footrest,
a trilatery articulated on the first quadrilateral
opposite of the latter to contribute to
support of a folder,
an elastic member intended to be interposed
between the first quadrilateral and the chassis,
- and a set of maneuver intended to be
posed between the first quadrilateral and the chassis
to assume a command and control function
manual control of the relative pivoting of said
system relative to the chassis and a function
stop and lock of said system in
a position of lowering or elevating the
structure.

 The invention also relates to a wheelchair comprising a lifting device according to the invention.

 Various other characteristics appear from the description given below with reference to the accompanying drawings which show, by way of non-limiting examples, embodiments of the subject of the invention.

 Fig. 1 is a side elevation showing, schematically, a wheelchair for disabled or disabled equipped with a device of the invention.

 Fig. 2 is a front view taken at a different scale along the line II-II of FIG. 1.

 Fig. 3 is a schematic view similar to FIG.

1, but illustrating a second characteristic position of a chair and device assembly of the invention.

 Fig. 4 is a schematic view showing an alternative embodiment of one of the constituent elements of the subject of the invention.

 Figs. 1 and 2 show, schematically, a wheelchair 1 comprising a frame 2 consisting of anterior and rear uprights 3 4 joined together by longitudinal members 5 and crosspieces 6. These various constituent elements define a seat bearing frame 7 and a backrest carrying frame 8 at the upper part of which can be provided handles 9 to facilitate the movement of the chair for a person attending the disabled subject.

 In a generally known manner, the chassis 2 is provided with carrying and driving wheels 10 and steerable steerable wheels 11.

 The frame 2 above corresponds to a chair of rigid design, but it is obvious that a substantially similar conformation is retained for a folding chair. Indeed, in such a case, the rigid elements forming the sleepers 6 are replaced by folding elements of known design.

 The chassis 2, described above, is equipped, according to the invention, with a lifting device which is designed as an articulated structure 12 carried by the frame 2. The articulated structure consists of two articulated systems 13, symmetrical with respect to a vertical plane of symmetry P of the chair or the carrier frame 2. Each articulated system 13 is intended to be laterally adapted to the frame 2 and is joined to the system 13 homologous by backrest elements 14, d These different elements are, in the illustrated example, formed by rigid structures, but it is obvious that a different embodiment can be adopted in the case where such elements must also meet the requirements of FIG. imperative of folding in concomitance with the possibility offered possibly by the carrier frame 2.

 Each articulated system 13 comprises a first deformable quadrilateral 17 consisting of two bars 18 and 19 joined by their ends located near the backrest frame 8, by a spacer bar 20. The quadrilateral 17 is intended to be arranged laterally, for example outside the corresponding lateral side of the frame 2, so that the bars 18 and 19 are substantially superimposed.

 The quadrilateral 17 is mounted on the seat frame 7 by a first point of articulation 21 provided between the free end of the lower bar 19 and, for example, the upper spar 5. A second pivot point 22 is provided between the upper bar 18 and the seat frame 7, so that the geometric axis of this point is substantially located in the upper front position of said frame 7. In the illustrated example, the point of articulation 22 is carried by an extension 23 formed by the corresponding anterior amount 3. In the case illustrated, the distance separating the articulation points 21 and 22 and that between the points 24 and 25 connecting the bar 20 to the bars 18 and 19, are equal and give the quadrilateral 17 a preferred form of parallelogram.

 A desired deformation of such a quadrilateral can be considered in order to adapt its characteristics according to the morphology of the subjects. In this respect, it may be provided to make the articulation point 21 adjustable in the horizontal plane towards the front or towards the rear of the carrier frame 2.

 Each articulated system 13 further comprises a second deformable quadrilateral 26 which is disposed on the frame 2, substantially in front of the seat frame 7. The quadrilateral 26 comprises a leg 27 connected by a pivot point 28 to an extension 29 of the bar 18 beyond the articulation point 22.

The extension 29 constitutes one of the sides of the quadrilateral 26. The leg 27 is connected to the corresponding front post 3 by a spacer bar 30 articulated on points 31 and 32. The spacer bar 30 represents the third side of the quadrilateral 26, the fourth of which is formed by the portion of the upright 3 between the articulation points 22 and 32.

 The leg 27 extends substantially below the point of articulation 31 and supports a footrest 33 in cooperation with the leg 27 of the articulated system homologous. Although not shown, the connecting means between the footrest 33 and the leg 27 are provided to allow a height adjustment and relative orientation.

 The hinge point 28 is preferably adjustable, so as to be able to modify the actual practical length of the extension 29 and adapt the inclination of the leg 27 according to the morphology of the subject.

 Each articulated system 13 comprises, moreover, an articulated trilateral 34 constituted by an amount 35 mounted articulated on the axis 24. The trilaterate 34 is composed of the upright 35, the spacer bar 20 and a triangulation bar 36 articulated, on the one hand, on the axis 25 and, on the other hand, on an axis 37 carried by the amount 35. The axis 37 is preferably adjustable in position on the upright 35, so as to allow a possible adjustment of the angle formed by the amount relative to the bar 18.

 Each articulated system 13 also comprises an elastic member 38 interposed between the deformable quadrilateral 17 and the frame 2. The elastic member 38 is interposed between the upper bar 18 and the lower spar 5, being adapted to these elements by dots. articulation 39 and 40 which are preferably adjustable in the forward or backward position of the frame 2.

The elastic member 38 is designed to assume a function of weight compensation and energy absorption, and a function of restitution, as appears in the following. The elastic member 38 may be constituted by a compensating spring or, preferably according to the invention, by a gas-type cylinder, advantageously provided with a valve for adjusting the transfer of its fluid.

Fig. 2 shows that the elastic member 38 is preferably placed inside the seat frame 7 of the frame 2.

 Each articulated system 13 further comprises an operating assembly 41 intended to assume a function of control, manual control of relative pivoting of the articulated system 13 with respect to the frame and a function of abutment and locking of said system in a position d maximum lowering corresponding to the sitting position, as shown in FIG. 1, or in an elevation position as is apparent from the following. To this end, the maneuvering assembly 41 comprises a lever -42 mounted articulated by a point 43 on the first quadrilateral 17 and, preferably, on the upper bar 18. The lever 42 is extended by a square arm 44 s extending towards the front part of the frame 2 and connected by a hinge 45 to a connecting rod 46 mounted by a pivot point 47 on the frame 2.The constituent elements of the assembly 41 are arranged laterally and externally to the articulated system 13, as can be seen from fig. 2.

 Fig. 1 shows that the assembly 41 is designed so that, in a maximum lowering position substantially corresponding to the sitting position, the pivot axis 43 is disposed below the imaginary line passing through the articulation points 45 and 47. This results in a geometric lock which opposes any inadvertent pivoting of the lever 42 in the direction of the arrow f1. The locking function is completed by a stop function determining the sitting position. This stop function is, for example, assumed by a cleat or the like 48 carried by the branch 44 and under which bears the connecting rod 46 in the position illustrated in the drawing. This stop may be main or preferably secondary by intervening in combination with a damper placed between the quadrilateral 17 and the seat frame 7.

 As said above, the two articulated systems 13 are joined by backrest, seat and footrest elements which are designed to establish a conjugation of their relative displacement and form with them the articulated structure 12.

 In the state illustrated in FIG. 1, the structure 12 occupies a maximum lowering position in abutment and locking and the chair then assumes a seat function for a subject occupying the seat, the backrest and the footrest. In this position, the elastic members 38 are compressed.

 When the subject wishes to be transferred from the sitting position to a pseudo-vertical position, he acts on the levers 42 in the direction of the arrow f1, so as to move the articulation points 43 beyond the alignment of the points 45 and 47 and thus break the lateral geometrical locks established by the sets 41. The levers 42 can thus pivot on the points 43 by being supported by the points 45 on the rods 46. This results in the combined elevation of the points 43 which controls the pivoting of the quadrilaterals 17 in the direction of the arrow c on the points 21-22.This pivoting, once initiated by the action on the levers 42, is supported, aided or maintained, according to the adjustments made by the elastic members 38 which restore the previously stored energy.

 Thus, the subject is progressively raised by the pivoting of the quadrilaterals 17 of the articulated systems 13, having the possibility of possibly controlling this pivoting movement by a retaining action on the levers 42, insofar as the action of restitution of the organs Elastics 38 is sufficient to support the pivoting of the structure 12 after unlocking by manual action on the levers 42.

 By pivoting the deformable quadrilaterals 17, the trilaterals 34 are raised and maintain the uprights 35 in their substantially initial orientation. this results in a gradual opening of the angle formed between the seat and back planes.

 Simultaneously, the downward pivoting of the extensions 29 subjects the quadrilaterals 26 to a corresponding deformation tending to lower the footrest 33. The legs 27 have a length such that, depending on the setting made in point 28, they rely on the floor when the structure 12 occupies the maximum elevation position shown in FIG. 3.

This position is reached, determined and locked by means of the two sets 41. Indeed, the relative pivoting in the direction of the arrow f1 of the levers 42 and the corresponding relative pivoting of the two quadrilaterals 17 have the effect of bringing the points 45 beyond the alignment of the pivot points 43.

 This results in a geometric locking in a stable elevation position, determined by the support of the branches 44 against stops 49 carried, for example, by the lower bars 19 deformable quadrilaterals 17.

 The above means allow, therefore, to maintain the structure 12 in an elevation position, as shown in FIG. 3, in which it represents a continuous plane of support and support for a subject maintained in a pseudo-upright posture, supported by the feet on the footrest 33.

 Stable support of the subject can be provided if needed by straps surrounding the legs and bust.

 When the subject wishes to control the reverse transition to the seated stable position, he acts on the levers 42 in the direction of the arrow f3> so as to break the geometric locking allowing the rotation of the levers on the articulation points 43. By effect traction force exerted on the connecting rods 46, the rotation of the levers 42 results in a pivoting of the two deformable parallelograms 17 in the direction of the arrow f4 and by a concomitant movement of the quadrilaterals 26 and trilaterals 34.

 When this movement is initiated, the weight of the armature 12 and the subject is responsible for the stressing of the springs 38 which store the restitution energy as the pivoting back to the lowering position of the articulated structure 12.

 The resilient members 38 are provided to provide some resistance to such stressing, so as to achieve a compensation of the weight supported and avoid a quick return to the stable position of maximum lowering. The levers 42 allow, as before, to control, if necessary, the pivoting of the structure 12 to this maximum lowering position.

 The adjustment of the relative position and the opposing stressing reaction by the elastic members 38 are, in practice, determined so as to obtain, for a subject of a given weight, a slow progressive return of the elevation position. maximum at the maximum lowering position. In such a case of adjustment, the reverse pivoting involves a small, but constant, action on the levers 42, so as to apply an additional force capable of overcoming the friction generated by the pivoting of the various elements constituting the articulated structure 12 and to come to join the work of the elastic organs 38.

 As is apparent from the foregoing, the means of the invention are simple, inexpensive, reliable and robust and allow, without additional external energy, to control a transfer from a maximum lowering position to an elevation position maximum and conversely of the articulated structure 12 ensuring either the support in a sitting position of a subject, or the maintenance of the latter in a pseudo-upright posture.

 The means of the invention offer a remarkable stability in the position of maximum elevation, since the articulated structure 12 finds, in the deployed position, an additional ground support through the legs 27 which increase the bearing surface determined by the points of contact between the ground S and the wheels 10 and 11.

 It should be noted that the particular conformation of the operating units 41 is also chosen so that the levers 42 represent, in the position of maximum eSévation, as illustrated in FIG. 3, lateral elements may contribute to a transverse wedge of the body of the subject if necessary.

 In some cases, it may be provided to include each actuator assembly 41 multiplying means of displacement amplitude, so as to reduce the pivoting amplitude of the lever 42. Each set 41 then comprises, as illustrated by FIG. . 4, a lever 42a articulated directly by the point 43a on the deformable quadrilateral 17. The lever 42a is associated by a hinge point 50 to a branch 51 which is articulated by a point 52 on a crank 53 itself hinged to a point 54 carried by the deformable quadrilateral 17. The end of the crank 53, opposite the hinge point 54, is connected by a hinge 55 to the connecting rod 46a.

 The assemblies 41a operate in a manner similar to that described above and assume the same functions for a lower angular pivoting amplitude of the levers 42a.

 The means of the invention make it possible to achieve a fast position transfer, without high physical expenditure and can, thus, be used relatively frequently by a subject wishing to adopt a vertical position to facilitate its general activity and the execution of common tasks. or, again, seeking a change of position favorable to the maintenance of more suitable physical conditions.

 Another advantage of the object of the invention lies in the fact that the means used are of a particularly small footprint and are included in the maximum space requirement of an ordinary wheelchair.

 Another important advantage of the object of the invention resides in the fact that the technical means recommended make it possible to constitute a lifting device representing a structure that can be easily adapted to an ordinary wheelchair, on the chassis of which the points are reported. necessary articulation.

 it thus becomes possible to consider the commercialization of the lifting device alone to allow the equipment of wheelchairs of conventional design or to design a clean manufacture of wheelchairs originally equipped with a device of the invention.

 As such, the invention is therefore a lifting device in the general sense, and a wheelchair, any design, including such a device.

 Another important advantage of the invention lies in the fact that the physical expense resulting from the action of the arms on the levers 42 can be reduced by taking advantage of the action of the body and, more particularly, of the bust on the part 12. In fact, insofar as a strap connects the bust of the subject to the backrest, a pushing action in the direction of the arrow f5 (FIG 1) has the effect of soliciting the tetrilaterals 34 which then tend to cause the quadrilaterals 17 to pivot in the direction of the arrow f2. Such action therefore contributes to reducing the force exerted on the levers 42.

 A traction exerted in the direction of the arrow f6, from the position according to FIG. 3, produces a similar aid for the return of the structure 12 in the siege position.

 The invention is not limited to the examples described and shown, since various modifications can be made without departing from its scope.

Claims (11)

CLAIMS:  1 - A lifting device for a wheelchair of the type comprising, on the one hand, an articulated structure adapted to the chassis of such a home and constituted by a backrest, a seat and a footrest hinged relatively in the extension the one another and, on the other hand, means for driving in relative pivoting the backrest, the seat and the footrest relative to the chassis,  characterized in that it is in the form of an articulated structure (12) constituted by two articulated systems (13) symmetrical with respect to a vertical plane of symmetry (P) intended to be adapted laterally to the frame (2). ) of an armchair and joined together by a backrest (14)> a seat (15) and a footrest (16), each articulated system comprising  a first deformable quadrilateral (17) for  to be mounted articulated on the substantially  front of an armchair chassis correspon  - at the seat to contribute to the support of a-seat,  a second deformable quadrilateral (26) articulated  partly on the first and partly on the  chassis to help support a rests  feet,  a trilatery (34) articulated on the first qua  drilater (17) as opposed to the second (26) for  contribute to the support of a file,  an elastic member (38) intended to be inter  between the first quadrilateral (17) and the  chassis (2),  - and a maneuvering assembly (41) intended to be  disposed between the first quadrilateral (17) and  the chassis (2) to assume a function of  Manual control and control of pivoting  relative to said system relative to the chassis and  a stop and lock function of said  system in a lowering position or  elevation of the structure.  2 - elevating device according to claim 1, characterized in that the first quadrilateral (17) of each system (13) comprises two bars (18-19) joined together at one of their homologous ends by a spacer bar (20) articulated and adapted to be mounted by their other homologous ends on hinge points (21-22) of the frame of a chair so as to be placed substantially in superposition.  3 - elevating device according to claim 1, characterized in that the second deformable quadrilateral (26) of each system is constituted by an extension (29) of an upper bar (18) constituting the first quadrilateral (17), such an extension extending forwards from the point of articulation (22) of said bar on the chassis, by a leg (27) hinged to the extension, by a spacer bar (30) hinged on both the leg and the frame, and the part of said frame between the joints (32 and 22) of the spacer bar and the extension on this frame.  4 - elevating device according to claim 1, characterized in that the trilatery (34) of each system is constituted by the spacer bar (20) bars (18-19) constituting the first quadrilateral (17), by a post (35) mounted on the hinge point (24) between the bar (20) and the upper bar (18) and by a triangulation bar (36) articulated on the one hand to the upright (35) and, on the other hand, on the point of connection (25) between this bar (20) and the lower bar (19) of the first quadrilateral (17).  5 - elevating device according to claim 1, characterized in that the elastic member (38) is provided to assume a compensation function by energy absorption during the lowering of the structure and the user and a function of restitution during the elevation.  6 - elevating device according to claim 5, characterized in that the elastic member (38) is constituted by a gas cylinder.  7 - elevating device according to claim 1, characterized in that the operating assembly (41) assuming a control function, control, stop and lock is constituted by a lever (42) articulated on the first quadrilateral (17). ) and attacking a connecting rod (46) intended to be articulated on the frame (2).  8 - Lift device according to claim 7, characterized in that the lever (42) attacks the connecting rod by means (51-53) amplitude multipliers displacement.  9 - elevating device according to claim 1, characterized in that the two articulated systems (13) side are joined together by the back members (14), seat (15) and footrest (16) of structure rigid.  10 - elevating device according to claim 1, characterized in that the two articulated systems (13) side are joined together by back members (14), seat (15) and footrest (16) of structure foldable.  11 - wheelchair for disabled and disabled, of the type comprising a frame (2) supporting an articulated structure (12) formed by a backrest, a seat and an articulated footrest in the extension of one another, characterized in it comprises a device according to one of claims 1 to 10.