EP1913917B1 - Foldable wheelchair frame - Google Patents

Abstract

The chassis has flanks (1, 2) connected by a pair of crosspieces (7, 8) that are pivoted with respect to each other. Backrest poles (22, 23) are mounted and articulated on the flank that carries the poles. A linkage assembly is formed by connecting rods (18, 19) and control arms (20, 21). The linkage assembly is connected to the crosspieces such that folding of the poles from a raised usage position permits the folding of the chassis by pivoting the crosspieces with respect to each other.

Description

The present invention proposes an improvement to the frame of foldable wheelchairs in order to facilitate their handling, particularly during folding and unfolding operations, as well as during storage ( DE 202051234 describes such a foldable wheelchair).

For this purpose, the object of the invention is a chassis as defined in the appended claims.

• la fig. 1 est une vue en perspective du châssis dans une première forme d'exécution, à l'état déplié,
• la fig. 2 est une vue en perspective du châssis de la fig. 1 équipé de deux roues porteuses et deux roues directrices dans le même état déplié,
• la fig. 3 est une vue latérale du même châssis à l'état complètement replié, sans les roues directrices mais en montrant l'encombrement des roues porteuses séparées du châssis,
• la fig. 4 est une vue en perspective du châssis dans une seconde forme d'exécution, à l'état déplié, avec une seule canne de dossier,
• la fig. 5 est une vue partielle en perspective latérale du châssis de la fig. 4,
• les fig. 6, 7 et 8 sont des vues partielles en perspective montrant certains détails d'exécution des châssis des fig. 1 et 4 et
• les fig. 9, 10 et 11 sont des vues partielles en élévation latérale et en perspective montrant différents agencements des cadres et armatures dans des variantes d'exécution du châssis.

Several embodiments and variants of this object are described hereinafter by way of examples, with reference to the appended drawings, in which:

• the Fig. 1 is a perspective view of the frame in a first embodiment, in the unfolded state,
• the Fig. 2 is a perspective view of the chassis of the Fig. 1 equipped with two load wheels and two steering wheels in the same unfolded state,
• the Fig. 3 is a side view of the same frame in the fully folded state, without the steering wheels but showing the space requirement of the separate load wheels of the chassis,
• the Fig. 4 is a perspective view of the frame in a second embodiment, in the unfolded state, with a single backrest cane,
• the Fig. 5 is a partial perspective view of the chassis of the Fig. 4 ,
• the Fig. 6, 7 and 8 are partial perspective views showing some of the execution details of the chassis of the Fig. 1 and 4 and
• the Fig. 9, 10 and 11 are partial views in side elevation and perspective showing different arrangements of frames and frames in alternative embodiments of the frame.

As will be seen, the frame arrangement which is the subject of the invention is characterized by a linkage having a suitable arrangement and connected by joints to at least one spider and at least one backrest rod articulated herself even on a chassis frame. This linkage makes it easy to maneuver the wheelchair folding and unfolding by pivoting a cane backrest.

The Fig. 1 shows a foldable wheelchair frame formed of two sides 1 and 2 each consisting of a rigid rectangular frame with two parallel and horizontal tubular sections 3, 4 connected by the front 5 and rear uprights 6. The two sides 1 and 2 are maintained parallel to one another but can be brought together or removed by means of a pair of braces 7, 8 also consisting of straight tubular sections pivoting one on the other by means of a vertical axis articulation 9 placed in the center of the length of the braces. At the front, the spider 7 is connected to the upright 5 of the sidewall 1 by a cap 10 which surrounds the amount and is, moreover, secured to the spider. Similarly, the spider 8 carries a hatch 11 which can pivot on the upright 5 of the side 2. On the back side, however, the spider 7 ends with a rigid amount 12 at the ends of which are mounted pivoting slides 13, 14 which are guided by the horizontal bars 3 and 4 of the side 2. A symmetrical arrangement with an upright 15 and slides 16, 17 guided by the bars 3 and 4 team the rear end of the cross 8. An identical arrangement of horizontal cross frame has already been described in the patent application European No 05405531.4 the same depositor, and the contents of which are incorporated herein by reference.

We will now describe the mechanism that facilitates the folding / unfolding operation of the chassis of the Fig. 1 . For this purpose, this frame comprises a linkage formed of two rods 18, 19 and two control arms 20, 21. These are each fixed to the base of one of the two back canes 22, 23 which allow to control and direct the chair. These rods pivot on joints 24, 25 placed, according to the Fig. 1 , between the upright 6 and the bar 3 of each of the flanks 1 and 2. They are coaxial. The front ends of the arms 20 and 21 are articulated by ball joints at the rear end of each of the rods 18, 19 which are hinged themselves at the front, also by ball joints, on the braces 8 and 7. joints of the control arms on the rods, as well as the length of the rods 18, 19 could be adjustable to allow the use of the same frame for chairs of different widths. As for the position of the joints between rods and braces, it will be chosen so that the folding of the canes of the back of the position of the Fig. 1 , extended position, in the folded position ( Fig. 3 ) causes the folding of the frame, the pivoting and sliding connections 12, 13, 14 on the one hand, and 15, 16, 17 on the other hand, moving the rear ends of the braces on the sidewalls 1 and 2 towards the rear of the frame. It is understood that mounting frames 26, 27 for carrying wheels and frames 28, 29 for front steering wheels can be placed on the sidewalls 1 and 2 at useful locations without hindering the operation of the backrest during the folding of the frame.

The Fig. 2 and 3 show an intermediate position and the final position of the folding maneuver. To the Fig. 2 , the carrying wheels 30 and 31 and the steering wheels 32, 33 are in place. We see that the carrier wheels are doubled by outer circles 34 which are fixed to them coaxially to allow training by hand. Reinforcements 26, 27 secured to the uprights 6 carrying axles 35, 36 for the carrying wheels 30, 31 may be fixed in different ways to the sidewalls 1 and 2 (see FIGS. Fig. 9, 10, 11 ). On examination of the Fig. 3 those skilled in the art will immediately understand that the described construction allows a maximum reduction of the size of the chair in the folded state and in particular its placement in a rectangular packaging container of reduced dimensions. The armatures 26, 27 carrying axles 35, 36 for the pivoting of the carrying wheels, rigidly fixed between the bars 3 and 4 of the sidewalls, behind the extreme position attainable for the sliding connections 12, 13, 14, and 15, 16 , 17, are not represented at the Fig. 3 .

The Fig. 4 and 5 show a second embodiment of the foldable frame according to the invention. Here we find two sides 1 and 2 each consisting of a frame with two horizontal bars 3 and 4 and two end posts 5 and 6. The two braces 7 and 8 are also present, but we see that the pivoting catches 10 and 11 are integral with the rear ends of the braces and provide a pivotal connection with the uprights 6 of the frames, while the front ends of the braces are secured to the uprights 12 and 15 connected to the pivoting slides 13, 14 for the spider 7, and 16, 17 for the cross 8. These sliders are shaped half-cylinders. With this embodiment, the rigidity of the frame is increased at the rear, while with the first embodiment, the rigidity is greater at the front.

As we see in Fig. 4 , a foldable backrest rod 37 is sufficient to control the opening maneuver or folding. On this cane, halfway up, is articulated a control arm 38 which extends obliquely downwards and pivots at its lower end on the slider 13 or on a rigid part integral with this slider. As the rod 37 is articulated at its lower end on the horizontal bar 3 in the vicinity of the hatch 10, it is understood that its folding actuates the spider 7 and therefore closes the frame. Compared to the case of Fig. 1 it may be noted that the spider is no longer attached to the frame from the front but from the rear, that is to say around the tube 6, which allows to reverse the direction of rigidity of the frame.

The Fig. 5 shows some details of execution. First of all, the hinge frame 39 of the cane 37 on the bar 3 can be moved according to the needs, more or less far from the hatch 10. This makes it possible to produce depth-adjustable chairs, because if one moves the cane back 37, it increases or reduces the very depth of the chair. Then, the joint 40 between the rod 37 and the control arm 38 is also adjustable. It comprises a slider sliding on the rod 37 and can be blocked by a screw. These arrangements make it possible, on the one hand, to modify the amplitude of the movements of the pivoting and sliding articulations of the braces on the frames and, on the other hand, to give the backrest a final position more or less inclined towards the rear according to the need comfort of the person occupying the chair, thereby creating a reclining chair. It should also be noted that the adjustment of the hinge point 40 can be done independently or not of the opening operation of the chair. If the two movements are dependent we have a fixed backrest (with several positions of the file but it remains a fixed folder compared to a given frame), if the two movements are independent we have a reclining backrest.

The Fig. 5 still shows, better than the Fig. 4 , a plastic plate 41 pivoting on the bar 38 and guided or not by the bar 3 according to the desired retraction movement, which can serve as a side guard or armrest, or masking the control arm by improving the aesthetics of the whole. Two other auxiliary devices, namely an automatic locking of the braces 42 and a release spring 43 are explained below with the description of a series of details ( Fig. 6 to 11 ) which can be provided in variants.

The Fig. 6 shows a first detail which relates to the first embodiment, with lower links 18, 19 connecting the control arms 20, 21 to the braces 7 and 8, as shown in FIG. Fig. 1 . According to Fig. 6 , the angle between the backrest rod 23 and the control arm 21 is fixed such that when the control arm is horizontal, that is to say in the alignment of the bar 3, the rod 19a a position slightly inclined downwards between its articulation on the control arm and its articulation on the spider. Normally, that is to say during the opening movement, the angle between the control arm and the rod is acute, but we see at the Fig. 6 it exceeds 180 degrees at the end of the deployment run. This results in a knee effect creating a slight blocking force of the frame in the open position, which is favorable in use.

A second detail concerns the second embodiment. The device 42 latching braces quickly mentioned in connection with the Fig. 5 is visible in more detail at the Fig. 7 . Two plates in superimposed arcs of circles are each fixed under or on one of the braces. One of the plates has a hole and the other carries a button with a rod, biased by a spring, so that when the final position of the braces is reached, the locking rod falls into the hole, this which blocks the device. The button can be easily raised by hand during the folding operation.

The Fig. 8 a further detail relating to the second embodiment, in the form of an unlocking device 43. A stud 44, in which is mounted a spring with a movable support button 45, is fixed on the lower bar 4 of the rigid frame in the vicinity of the end position of the lower slide 14. At the end of the opening stroke, when the latch 42 comes into action, the stud 44 operates in abutment for the mobile upright 12, which therefore places the spring of the button 45 in the arming position. When unlocking, the spring slightly pushes the upright 12 and the latch plate 42, the latter being prevented from falling back into the locked position.

Finally, Fig. 9, 10 and 11 represent different possible variants according to the invention in the execution of the rigid frames constants flanks 1 and 2 of the chair and auxiliary frames which are attached thereto. An advantageous solution is that each armature 26 or 27 which carries the axle of the carrier wheel is assembled with the support of the backrest cane and the amount receiving the fixed axis spider cap. The Fig. 9 to 11 show three ways to achieve this assembly on a frame that, unlike the frame of Fig. 1 and 4 has profiled upper and lower bars having a different section of a tube. These frames can also be made in the form of separate parts independently fixed on the frames.

• une ouverture du fauteuil facilitée grâce aux bras de levier constitués par les cannes du dossier;
• un encombrement réduit après pliage, ne nécessitant aucun démontage d'une partie du dossier ou du châssis (voir fig. 3);
• la possibilité d'utiliser un même châssis pour plusieurs largeurs de fauteuils par réglage des positions des articulations des bras de commande sur les biellettes et de la longueur des biellettes;
• fonctionnement de pliage facilement compréhensible du fait que le maniement se fait au niveau des poignées de poussée du fauteuil.

Among the many advantages of the foldable wheelchair frame according to the invention, there may be mentioned in particular the following advantages:

• a facilitated opening of the chair thanks to the lever arms constituted by the canes of the backrest;
• a reduced space requirement after folding, requiring no dismantling of part of the backrest or the chassis (see Fig. 3 );
• the possibility of using the same frame for several widths of armchairs by adjusting the positions of the articulations of the control arms on the rods and the length of the rods;
• folding operation easily understandable because the handling is at the push handles of the chair.

Claims (10)

1. A foldable wheelchair frame including at least two frame components (1, 2) connected by at least a pair of cross-pieces (7, 8) pivoting one on the other, at least one back holder (22, 23; 37) mounted on one of the components and a linkage (18, 20, 19, 21; 38) connecting said back holder with the cross-pieces, characterised in that said components of the frame form two rigid frameworks (3, 4, 5, 6; 3, 4, 5, 26; 3, 4, 5, 27), in that the cross-pieces (7, 8) of each of said pairs pivot one on the other about a vertical axis (9), so as to keep the frameworks in a vertical utilization position and are connected with each framework (1, 2), at one end by a horizontally sliding and pivoting connection (12, 13, 14, 15, 16, 17) to one of said frameworks (1, 2), and at the other end by a pivoting connection only (5, 10, 11; 6, 10, 11), and in that each holder (22, 23; 37) is articulated on one element of the framework of one of the sides, about a horizontal axis (24, 25; 39) perpendicular to the framework, said linkage being so arranged that the turning down of the holder from a raised utilization position involves the folding of the frame (1, 2) through the relative pivoting of the cross-pieces, one on the other, in each pair.
2. A frame according to claim 1, characterised in that locking means are provided, so that in the normal utilization position of the wheelchair, the holder (22, 23; 37) is rigidly fixed to the framework supporting it so that the wheelchair can be moved by pushing the holder.
3. A frame according to claim 2, characterised in that the linkage includes a side arm (20, 21) integral with the holder at the lower end thereof, and a pull and push traction rod (18, 19) articulated between said arm and a cross-piece, with the articulation point on the cross-piece being so selected that the turning down of the holder from the utilization position into the maximum lowered position moves the sides (1, 2) from the maximum distant position to the closest possible position through the relative pivoting of the cross-pieces in the closing direction and the sliding of the pivoting and sliding connections (12, 13, 14, 15, 16, 17) on elements of the frameworks.
4. A frame according to claim 3, characterised in that the articulation point of each connection rod (18, 19) on the side arm (20, 21) of the holder can be adjusted.
5. A frame according to claim 3, characterised in that the length of said pull and push connection rods (18, 19) can be adjusted.
6. A frame according to claim 3, characterised in that the linkage is so adjusted that, when the holder is in a maximum raised position, the angle between the pull and push connection rod and the side arm of the holder is greater than 180 degrees (Fig. 6).
7. A frame according to claim 2, characterised in that the linkage includes a control arm (38) articulated at one end on the holder (37) and at the other end on a sliding element (13) of said pivoting and sliding connection.
8. A frame according to claim 7, characterised in that the articulation point (40) of the control arm (38) on the holder (37) can be so adjusted as to enable the modification of the inclination of the holder for the totally opened position of the frame.
9. A frame according to claim 7, characterised by a device (42) for blocking the cross-pieces in the open position, positioned at the articulation (9) of the cross-pieces one on the other, and by a spring stopper (43) mounted on one element of the frame (4) actuated by a sliding element (14) of the sliding connection upon completion of the opening and cooperating with the locking device (42) to stop the position of the sliding element upon arming the spring, the displacement of the sliding connection upon the closing of the frame being started further to the action of the spring upon the raising of the locking device (42).
10. A frame according to any one of the preceding claims, characterised in that said frame components include assemblies of prefabricated elements liable to be provided with various additional elements (26, 27) which provide the pivoting of the holder or the holders, the mounting of the carrying wheels and the driving wheels and/or the pivoting connections with the cross-pieces.

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