EP0754441B1 - Foldable wheelchair - Google Patents

Abstract

The two side supports (12,13), fixed with a drive wheel (18,19) and a runner wheel (20,21), which are rigidly joined by a horizontal main cross-bar (34) and a subsidiary cross-bar (12,13). The main cross-bar is formed by two arms (38,39) at right angles to the main cross-bar, and linked to the side supports and joined by a hinge link. At least one of the arms is adjusted parallel with the pivot axle of the drive wheels (19). The one arm (38) has a locking piece in the form of a swivelling locking lug (56). The other arm has an elongated catch, from which part of the catch surface facing the locking lug is formed.

Description

The invention relates to a folding wheelchair or a collapsible wheelchair the preamble of claim 1. Such a folding wheelchair is out EP-A-0 312 969 is known.

Foldable or foldable wheelchairs of this type have been known for a long time. A need for it arose especially with the advent of automobiles, which are larger to overcome Distances are more suitable than wheelchairs, but for which numerous places, in particular Living spaces, workplaces and public buildings are not accessible, so the There was a desire to have a wheelchair folded to small dimensions in the automobile to carry with you and, if necessary, to be used when opened. To such Wheelchairs are numerous and sometimes contradictory in terms of their construction Requirements. In addition to the properties that are also non-folding Wheelchairs have to be particularly lightweight in folding wheelchairs, sufficient stability during use and easy handling when folding he wishes; it is also advantageous to design the folding wheelchair in such a way that it ie as 'hard' when needed, i.e. completely free of play and rigid, or proves to be 'soft' Regarding weight, you can get satisfactory results by looking at the general Principles of lightweight construction, both in terms of shape and in the selection of the ones used Materials, tracked.

In terms of stability, there is a significant advance over the traditional ones Folding wheelchairs, which were a kind of director's chair with wheels, in that you use a closed frame. Such a framework essentially exists two in the longitudinal direction, i.e. side beams running in the direction of travel of the wheelchair, which are connected by two cross members running transversely to the direction of travel. On the side straps is one of the large drive wheels in the rear, upper area and one in the front, one of the very small wheels attached to the lower area. The side straps are in angled in the shape of an L and have a horizontal arm at the level of the seat and an oblique arm pointing downwards and forwards from the front end of the seat on. The cross members connect the side members, with a main cross member under the seat is arranged and a secondary cross member through the footrest and its fastening device is formed. So that the frame is rigid, the connections of the longitudinal and Crossmember should be as free of play as possible.

The foldability of the wheelchair is due to the fact that the cross beams, which determine the distance between the side members in the operating state, relative to the Let the side members fold into a position in which this distance is as small as possible. So that the folding wheelchairs can also be easily handled by the disabled, the cross beams, which are brought into a different position during the folding process, in a simpler way Let move relative to each other and relative to the side longitudinal beams. This requires that the necessary game is available.

It can be seen that there is a core problem in the design of folding wheelchairs in it there is, the necessary for the foldability, relatively movable components design that they can be locked to one another with as little play as possible and in the operating position Collapse are slidable against each other as smoothly as possible. There is also a to provide as 'rigid' a frame as possible so that the running and driving behavior are optimal leaves.

DE-33 33 570-C2, for example, describes a folding wheelchair of the type mentioned, but which has various disadvantages.

A first disadvantage of this prior art folding wheelchair is either its Stability in use is insufficient or it cannot be folded easily; the hinge joint, which connects the two legs of the main cross member, has either play on, which gives you enough easy foldability but no stability reached, or it is free of play, which then gives sufficient stability, not but achieved a smooth foldability. One consequence of this arrangement is that the folding wheelchair is either soft when there is play or in use hard "if there is no game, but in this respect you don’t adhere to the Allows the user's wishes and needs to be adjusted. One possibility is one such soft / hard attitude exists; but it must already during the assembly of the Folding wheelchair take place, their change accordingly requires a partial disassembly of the folding wheelchair and therefore cannot easily be used by the user or another layperson be accomplished.

Another disadvantage of the previously known folding wheelchair is seen in that both legs extend over the entire width of the wheelchair, one leg in a slot-like longitudinal recess of the other leg is arranged so that touch the legs in two separate, parallel contact planes. This as a result the wide leg of relatively heavy construction was probably in the incorrect assumption chosen to increase the stability by the legs in the operating position not only in one but in two contact levels and moreover touch the entire width of the folding wheelchair. But that does not mean the foldability too much is hindered, must between the outer leg parts of one leg and the a certain, albeit minimal, play is present on the other thighs arranged on the inside his; the legs can therefore not be pressed against each other by the locking device that they are simultaneously along two opposite contact planes touch to transmit power. Because the locking device is also unsuitable for that To press legs together at least in one of the possible contact planes is the middle legs have the inclination between the surfaces delimiting the recess of the other leg back and forth, which naturally has a negative effect on the stability effect.

A third disadvantage of the previously known folding wheelchair relates to the locking device with which the two legs are locked in the operating position. It consists of one Rest area, which is formed by holes in the legs, which in the operating position align, as well as from a locking body in the form of a locking bolt, which is in the locking position is recorded in the aligned holes. The relatively weak trained locking bolt is subject to considerable transverse forces, through which it is plastic is deformed. When folding the folding wheelchair, the solution of Locking and then the actual folding process take place. To release the lock the locking bolt mentioned must be moved out of the aligned holes are pulled out. The execution of such a movement is anyway not easy and is made difficult by the fact that no ergonomically or at least sufficiently large handle is provided, which when the locking bolt is actuated can be grasped by hand. The pulling out of the locking bolt is also complicated by its plastic deformation described above. The implementation the actual folding process also proves difficult because there is no contact surface is present, which is intended for gripping when manually folding and is suitable. Unfolding and getting ready for operation is even more difficult the folding wheelchair, because the legs have to be brought into one position which exactly aligns the holes, which is not easy, on the one hand due to the game the hinge joints which connect the legs to one another and to the side beams, and on the other hand, because practically no visual inspection is possible. Even if they succeed Bring the legs into a position in which the holes are really aligned, and the legs To keep in this position, the linear insertion of the locking bolt proves to be difficult, due to the small opening that has to be made exactly, the insertion movement, which must be exactly linear so that the locking bolt does not jam, and due to the already mentioned deformation of the locking bolt.

The object of the invention is thus seen in creating a folding wheelchair of the type mentioned which does not have the disadvantages mentioned and which is extremely stable in the operating position, which is easy to operate when folded and unfolded and which is easy to operate and hard / soft-adjustability offers.

This solution according to the invention This object is achieved by the features of the characterizing part of patent claim 1.

Preferred developments of the folding wheelchair according to the invention are defined by the features of the characterizing parts of subclaims 2 to 14 .

The new folding wheelchair differs from the known one by several features Folding wheelchair according to the prior art, which features in combination the inventive Get the task done. First of all, these characteristics are parallel to the wheel axis Deliverability of at least one of the ones at right angles to the main cross member Leg of the main cross member, second, the only along one contact surface touching leg of the main cross member and third, the elongated design of the cross for the movement of the locking body directed locking surface on which the locking body any one can run up. The effects achieved with these three characteristics are described in detailed below.

The first feature of the new folding wheelchair according to the invention relates, as mentioned, to the Deliverability of at least one of the axles parallel to the main cross member parallel to the wheel axis extending leg of the main cross member in the direction of the longitudinal central surface of the Folding wheelchair; through such a delivery, the game of the hinge joints between the side members and the main cross member and between the legs of the main cross member To get picked up. This increases both the stability of the folding wheelchair in its operating position as well as its easy foldability. The improvement of Stability by avoiding the game is obvious and requires no further explanation; the ease of folding comes from the fact that the game of Hinge axes can be chosen relatively generously, precisely because of the possibility there is to cancel this game in the operating position by the delivery of the legs. It is also important that the folding wheelchair by choosing the size of the Infeed between a minimum and a maximum value arbitrary from soft to can be set to 'hard', the rigidity of the closed frame being 'soft' Folding wheelchair is less than the play-free and therefore hard 'folding wheelchair. in the Contrary to the pre-setting on the assembly side of the known folding wheelchair is one such setting in the wheelchair according to the invention in a simple manner by the user even possible, which enables him to change his folding wheelchair the attitude mentioned the respective terrain conditions or other needs adapt. The infeed of the legs of the main crossbeam also enables to compensate for wear-related play.

The second feature according to the invention relates to the design and arrangement of the legs of the main cross member. In contrast to the legs of the previously known folding wheelchair the legs of the main cross member of the folding wheelchair according to the invention overlap only in a central area where they locked themselves in the operating position or in the locked position Touch the state along only one contact plane and are at right angles to the main cross member arranged. By releasing the locking device, the mutual pressure the contact areas of the overlapping areas of the two legs are canceled, so that due to the absence of frictional forces, the two legs move without effort can be easily pivoted against each other. It is easy to see that this arrangement the ease of folding; less obvious is that stability at the same time is increased in the operating position, which is to be explained below. With the known Wheelchair, as already described, the legs are designed so that their mutual Touch should take place in two contact levels; such a double touch can but, as explained above, does not come about, that is the desired stability is not reached. In contrast, you can achieve with the inventive training the leg, which touch in only one contact plane, but through the locking device are actually pressed together without play, a high stability.

The third feature according to the invention relates to the design of the locking device itself. According to the invention, the locking device is designed in such a way that all relevant disadvantages, which the known folding wheelchair has can be avoided. The rest area is elongated and directed transversely to the movement of the locking body, and the locking body can run onto the rest area at any point. Any existing Game that is intended or created by wear and that is the relative location of the two legs in their longitudinal direction, i.e. transverse to the direction of travel of the folding wheelchair, influenced, so does not make it difficult to actuate the locking device. This to a certain extent location-dependent locking, it is to be attributed to that described above advantageous possibilities of the delivery of the legs can be fully utilized, especially to make the folding wheelchair 'hard' or 'soft' as needed, whereby yes the relative position of the legs is changed. Another advantage of the new locking device is that the locking body designed as a locking lug is pivotable formed and pivotable to the locking surface or away from it; such a swivel motion is much easier to do than the linear push or pull movement, which is necessary for actuating the locking bolt according to the prior art. A Spring device tensions the locking lug, or a lever device, on one arm the locking lug is arranged towards the locking position. In addition, a large handle provided on the other arm of the lever device, the actuation of the lever device and thus the locking lug easier and therefore also for easier implementation of collapsing and unfolding. After all, it is - in contrast to the weak locking bolt of the previously known folding wheelchair, which is actually only for Positioning the legs is good - the locking device of the folding wheelchair according to the invention massive design and it therefore enables the legs to be pressed together in such a way that high stability is guaranteed. In addition, a one-handed folding operation be provided, which results in a further considerable operating advantage.

In summary, it can thus be stated that the folding wheelchair according to the invention both in terms of its stability in use and its comfort Foldability advantageously differs from the previously known folding wheelchair. The advantages, which are aimed at by the delivery made transversely to the direction of travel achieve if a feed device is provided for one of the two legs. Considering the very small distances over which such delivery devices have their effect unfold, as well as to generate a symmetrical infeed, it is advantageous to provide feeders for both legs.

The delivery devices can be designed such that they have a delivery body; which acts transversely to the direction of travel or in the longitudinal direction of the leg by it is displaceable relative to the side support to which the leg is articulated.

Advantageously, the deliverability is infinitely variable, in that the delivery body is moved by means of an delivery element Move over a wedge or helical surface leaves.

In a preferred embodiment, the delivery body is in a breakthrough plate-shaped extension of the side carrier arranged in the direction of travel, its surface facing the leg abutting the latter. The breakthrough is on Outside or the side facing away from the leg of a rigidly attached to the neck Cover plate closed. The feed element in the form of a screw or an eccentric disc is rotatably accommodated in this cover plate.

According to the invention, the latching area is on a surface running in the infeed direction the leg is arranged, the actual locking surface being the one opposite the locking nose Section of the rest area acts on which the locking nose runs. Since the locking lug always finds a suitable resting area regardless of location, on which it can run, there is no need for an adjustment for the locking device to be provided to the extent of the delivery of the legs or the selected Local adjustment of the leg length, which will be discussed further below adapt. A mostly flat outer surface of a is usually used as the rest area the leg is used, while the locking lug swivels on the other of the legs is articulated.

The pivotable locking lug or the lever device on which the locking lug is arranged is articulated via a locking axis on the leg that is not with the rest area is provided. Although other constructive solutions are also conceivable, the best locking effect is obtained if the locking axis is parallel to the main cross member and is thus arranged transversely to the direction of travel.

The locking lug must be in its active position when the folding wheelchair is in the operating position the locking surface can be fixed. The easiest way to do this is that the lever device, which contains the locking lug, is biased to the operative position, which is advantageous Way is possible with a spring device. The lever device can in one Further development of the invention can be designed as a one-hand operation and then provides further advantageous simplification of the operation of the folding mechanism.

It has already been mentioned that the length of the main crossmember is adjustable, which allows you to can change the width of the folding wheelchair, with the purpose of meeting the needs of its users Adapt users. If the two legs also to save weight of the main cross member do not extend across the entire width of the folding wheelchair, so they overlap with those arranged in the area of the longitudinal median plane of the folding wheelchair Ends, this area of overlap being greatest when a minimum Width is desired, and decreases when larger widths are set. The adjustment the width is not infinitely variable because of the complex telescopically extendable device would be necessary on at least one of the cross beams, and one with other means can cause an adjustment in sufficiently small steps or steps, as follows is described. Of the two legs, which are connected by a hinge joint are connected, not only has at least one for receiving the hinge axis one hole but a large number of axially parallel holes. These holes are at a distance from each other to overlap with the other leg intended area of the thigh distributed. Optionally, one of the holes with the Bore the other leg in alignment and a bolt in the Hinge axis introduced. It is obvious that you can limit the number of settings increases, although the second leg has a large number of holes that are not in the the same distance as the holes in the first leg are to have.

A device is advantageously used to fine-tune the play of the hinge axis with an adjusting nut. As this is the result of numerous folding operations which affect the hinge joint suffering, who has a tendency to adjust and even to loosen, is an advantage Safety device is provided to fix the adjusting nut in its target position. For example can be chosen an adjusting nut, which in a known manner with one to her axially parallel grub screw, which engages in one of the concavities of the adjusting nut becomes.

In the conventional folding wheelchairs, the legs or the corresponding scissor-like components move in a vertical plane during the folding process, that is to say they carry out pivoting movements about horizontal pivoting axes. Such a construction of the legs or the corresponding scissor-like components is also possible in the folding wheelchair according to the invention; but it has proven to be much cheaper to arrange the legs one above the other and at right angles to the main cross member, so that they move in a horizontal plane when folding, which is synonymous with the fact that they rotate about vertical pivot axes. The advantage of the vertically arranged axes is to be seen essentially in the fact that they are less exposed to lateral forces and consequently to bending, which prevents jamming or obstruction of the pivoting movements and thus the folding process. So that the folding wheelchair is as stable as possible, it is advantageous if its main cross member, which contributes a relatively large amount to the weight, is arranged as deep as possible, that is, is arranged under the seat, as is also the case with the folding wheelchair according to DE-33 33 570-C2 ; however, the main cross member is arranged there under the rear area of the seat surface, so that the center of gravity is limited at the edge of the base, which is defined by the lines connecting the drive wheels and the running wheels. In the folding wheelchair according to the invention, the stability is further increased by moving the main cross member forward, so that it is - seen in the direction of travel - approximately below the center of the seat and thus at least approximately below the center of gravity. This also improves the steerability of the new folding wheelchair.

Fig. 1

einen Klapprollstuhl nach der Erfindung, von welchem einzelne Teile weggebrochen sind, in vereinfachter - teilweise schematischer - Darstellung, in einem Schaubild;

Fig. 2

einen Teil eines in Längs- bzw. Fahrtrichtung angeordneten rechten Seitenträgers des in Fig. 1 dargestellten Klapprollstuhls, in einer seitlichen Ansicht, von aussen gesehen;

Fig. 3

den in Fig. 2 dargestellten Seitenträger, in einem vertikalen Längsschnitt;

Fig. 4

den in den Fig. 1 - 2 dargestellten Seitenträger, in einem Schnitt längs der Linie 4 - 4 der Fig. 2;

Fig. 5

die im Seitenträger der Fig. 2 - 4 angeordneten Teile der Zustellvorrichtung, nämlich den einen Ausschnitt aus dem Seitenträger, den Zustellkörper und die Deckplatte sowie den rechten Schenkel des Hauptquerträgers, vereinfacht, in explodierter Darstellung, in einem Schaubild;

Fig. 6

den Hauptquerträger des in Fig. 1 dargestellten Klapprollstuhls, in einer seitlichen Ansicht, von vorne;

Fig. 7

den rechten Schenkel des in Fig. 6 dargestellten Hauptquerträgers, in einer Ansicht von oben;

Fig. 8

den linken Schenkel des in Fig. 6 dargestellten Hauptquerträgers, in einer Ansicht von unten;

Fig. 9

die Arretiervorrichtung zur gegenseitigen Arretierung der in den Fig. 7 - 8 dargestellten Schenkel des in Fig. 6 dargestellten Hauptquerträgers, in einem Schaubild, ohne Einhandbetätigungs-Vorrichtung;

Fig. 9A

einen Schnitt durch die Arretiervorrichtung; und

Fig. 10

eine Einzelheit der gegenseitigen Befestigung der beiden Schenkel des Hauptquerträgers.

The already mentioned and other advantages of the folding wheelchair according to the invention are described in detail below using a preferred exemplary embodiment and with reference to the drawings. It shows:

Fig. 1

a folding wheelchair according to the invention, from which individual parts have broken away, in a simplified - partially schematic - representation, in a diagram;

Fig. 2

a part of a right side member arranged in the longitudinal or driving direction of the folding wheelchair shown in Figure 1 , seen from the outside in a side view;

Fig. 3

the side carrier shown in Figure 2 , in a vertical longitudinal section.

Fig. 4

the side carrier shown in Figures 1 - 2 , in a section along the line 4 - 4 of Fig. 2.

Fig. 5

. in the side support of Figure 2 - arranged 4 parts of the feed device, namely a section from the side support, the Zustellkörper and the cover plate and the right legs of the main cross member, simplified, in exploded representation, in a perspective view;

Fig. 6

the main cross member of the folding wheelchair shown in Figure 1 , in a side view, from the front.

Fig. 7

the right leg of the main cross member shown in Figure 6 , in a view from above.

Fig. 8

the left leg of the main cross member shown in Figure 6 , in a view from below.

Fig. 9

the locking device for mutual locking of the legs shown in Figures 7-8 of the main cross member shown in Figure 6 , in a diagram, without one-hand actuation device;

Figure 9A

a section through the locking device; and

Fig. 10

a detail of the mutual attachment of the two legs of the main cross member.

It is anticipated that the description and the claims on the folding wheelchair Obtain in the opened state, i.e. in the operating state, and that information such as 'top', 'bottom', 'left', 'right', 'front', 'back' always on one on a horizontal surface standing folding wheelchair, which is seen in the forward direction.

The folding wheelchair shown in FIG. 1 , hereinafter referred to briefly as wheelchair 10 , has a left side support 12 and a right side support 13 . The two side beams 12, 13 have approximately the shape of an inverse L and each have a horizontal arm 12a, 13a and an arm 12b, 13b pointing obliquely from the bottom and down.

The horizontal arm 12a of the left side carrier 12 has in its rear region a vertical plate-like extension 14 , which is also referred to as a wheel carrier 14 , and to which a drive wheel (not shown) can be fastened via an adapter plate 16 ; In a symmetrical arrangement, a drive wheel 19 is attached to an attachment (not visible) of the right side support 13 via a further adapter plate 16 .

Both the wheel carrier 14 and the adapter plates 16 have a large number of bores. This provides numerous possibilities for attaching the adapter plates 16 to the wheel carriers 14 on the one hand and, on the other hand, the drive wheels 19 to the adapter plates 16 , so that the wheelchair 10 with its geometry can be adapted to the needs of different users and, if appropriate, to changing needs of a particular user ,

The drive wheels 19 are fastened in a conventional manner via thru axles with spring-operated fixing elements thru axles and can therefore be easily dismantled for transporting the wheelchair 10, for example and a car, whereupon the remaining, now significantly less bulky part of the wheelchair 10 is lifted much more easily and can be supplied.

At the lowest area of the inclined arms 12b, 13b two impellers 20, 21 are fastened in the usual way, the diameter of which is significantly smaller than the diameter of the drive wheels 19.

Arranged on the horizontal arms 12a, 13a of the side supports 12, 13 is a foldable sheet blank which forms a seat surface 22 and on which a seat cushion 24 is fastened with the aid of a Velcro strip. To the side of the seat surface 22 , horizontal thin plates 26, 27 are arranged on both sides, in a vertical arrangement, as clothing protection.

From the rear area of the horizontal arms 12a, 13a of the side supports 12, 13 , struts 28, 29 extend approximately vertically upwards, between which another fabric blank, which forms a backrest 30 and how the seat surface 22 can be padded with a cushion (not shown), is arranged. The angle which the vertical struts 28, 29 enclose with the horizontal arms 12a, 13a of the side supports 12, 13 is adjustable, which in turn serves to adapt the geometry of the wheelchair 10 to the respective needs.

The side beams 12, 13, which are arranged in a plane parallel to the direction of travel, are connected by two cross beams, namely a secondary cross beam and a main cross beam 34 , whereby a closed, relatively rigid frame is formed. The secondary cross member, not shown, is located at the level of the lower ends of the inclined arms 12b, 13b of the side members 12, 13 and is combined in the usual way with a footrest which is designed to be foldable. The main cross member 34 is arranged centrally under the seat surface 22 , ie at least approximately below the center of gravity of the wheelchair 10 loaded with a user ; This arrangement achieves a high level of stability and easy steerability of the wheelchair 10.

The main cross member 34 according to FIGS. 6 to 8 consists essentially of two legs 38, 39 articulated almost at right angles in the unfolded state . The right leg 38 has a bearing body 40 for receiving a vertical pivot axis, not shown, via which it is on the right wheel carrier articulated and thereby indirectly attached to the right side member 13 ; Correspondingly, the left leg 39 has a bearing body 41 for receiving a pivot axis, also not shown, via which it is articulated on the left wheel carrier 14 and is thus indirectly attached to the left side carrier 12 . The cross sections of the elongated parts of the legs 38, 39 which extend under the seat surface 22 are essentially rectangular, various recesses being arranged to reduce the weight and for design reasons. With their ends opposite the bearing bodies 40, 41 , the legs 38, 39 overlap in the region of the longitudinal central surface of the wheelchair.

The left leg 39 lies with its lower surface 39u on the upper surface 38o of the right leg 38 , so that the surfaces 380, 39u form the contacting, flat and horizontal contact surfaces of the legs 38, 39 .

The overlapping ends of the legs 38, 39 of the main cross member 34 are articulated to one another in the manner of a hinge joint and about a vertical hinge axis 44, which is only shown in FIG. 10 , from their parallel position, which they assume in the operating state of the wheelchair 10 , pivotable relative to each other in a rest position, not shown, which they occupy when the wheelchair 10 is folded. The legs 38, 39 therefore form a right angle with the side supports 12, 13 in the operating state, while in the folded state they are directed almost parallel to the side supports 12, 13 .

The wheelchair 10 is adjustable in width to adapt to changing needs. For this purpose, the secondary crossmember and the main crossmember 34 are designed such that their length can be optionally changed, whereby conventional and therefore not further described design measures are provided for the adjustment of the secondary crossmember. The adjustability of the main cross member 34 is achieved in that the overlap area of the legs 38, 39 is lengthened or shortened. To make this possible, the two legs 38, 39 each have several, in the present case five, parallel bores 46a-46e and 47a-47e . Depending on the desired width of the wheelchair 10 , one of the bores 46a - 46e of the leg 38 is aligned with the suitable one of the bores 47a - 47e of the leg 39 and the hinge axis 44 is arranged in the selected coaxial bores, in the present case 46c, 47a . The hinge axis 44 is fastened and its play is adjusted by means of a screw device, an adjusting nut 48 shown in FIG. 10 being used for fine adjustment of the play. The adjusting nut 48 is designed such that it is secured by means of a locking screw 50 which, depending on the position of the adjusting nut 48 , can be screwed into one of four bores 52a-52d, in the present case 52b or 52c . The locking screw 50 prevents the adjusting nut 48 from being adjusted or loosened, which would otherwise be feared due to the relative rotation of the legs 38, 39 when the wheelchair 10 is folded.

The two legs 38, 38 of the main cross member 34 are locked to one another in the operating position of the wheelchair 10 when they assume the position shown in FIG. 6 . For this purpose, a locking device is provided, in which, in the locked state, a locking surface of a locking body, which is articulated on one of the legs, bears against a locking surface on the other of the legs under the action of a fixing element exerting a force on it. 9 , in the present wheelchair 10, the locking body is designed in the form of a locking nose 56 on a first arm of a lever device 54 ; the second arm of the lever device 54 is provided with a handle 70 ; the lever device 54 and thus also the locking body or the locking nose 56 are articulated on a shoulder 58 of the right leg 38 by means of a horizontal locking axis 60 . The first arm of the lever device 54 fastened to the right, lower leg 38 with the locking nose 56 engages under the left, upper leg 39 from the rear . Its locking surface is designated 56v . 9 , the locking surface 62, on which the locking surface 56v comes to rest in the locked state, is formed by a section of an elongated locking region 64 which extends along the rear vertical surface 39h of the left upper leg 39 . The latching surface 62 and the latching area 64 are indicated in FIG. 9 with dash-dotted lines, but in reality they are not recognizable by the leg 39 , unless they are subject to slight wear and tear due to frequent actuation of the locking device. 9A, the lever device 54 is pretensioned in the assembled state in such a way that the surface 38o is pressed against the surface 39u . The spring device, not shown, is received, for example, in a recess in the right leg 38 .

On the other hand, the ergonomically favorable handle 70, with which the locking device can be actuated in a simple manner, is clearly recognizable in FIG. 9 . This handle 70 can also advantageously - not shown for clarity - be designed as a so-called one-hand operation of the folding device.

The purpose of the elongated design of the latching area 64 is to provide the locking lug 56 with a latching surface 62 which is not delimited on the side at any point at which it can be located. This greatly facilitates the mutual locking of the legs 38, 39 when the wheelchair 10 is ready for operation, as has already been explained in detail above. The arrangement just described is provided because the locking tab 56, depending on the set width of the wheelchair 10 and depending on the delivery of the legs 38, 39, which will be dealt with later, assume a position which is variable over a certain distance along the width of the wheelchair 10 can. It should also be pointed out that the lower front edge of the left leg 39 has a bevel 39s which has at least approximately the same inclination as the surface 56s of the locking nose 56 that slopes downward and downward. Firstly, this ensures that there are no fitting problems between the lever device 54 of the leg 38 and the leg 39 , and secondly that the wheelchair 10 is made easier to open because the locking lug 56 with its beveled surface 56s on the beveled surface 39s of the leg 39 slides, comes to rest, which facilitates the pivoting of the lever device 54 clockwise in Fig. 9 . The spring device (not shown) results in the mutual locking of the legs 38, 39 in the position shown in FIG. 9A .

The above-mentioned infeed of the legs 38, 39 parallel to the wheel axis of rotation or in the direction of the longitudinal center surface of the wheelchair 10 is described in more detail below. As mentioned at the beginning, 10 opposing demands are placed on the wheelchair. On the one hand, it should be as rigid as possible in its operating position, so that the aim is to connect the various components with as little play as possible. On the other hand, the wheelchair 10 should be foldable without great effort, for which purpose there must be a relatively large amount of play in the same connections. This applies in particular to the articulated connections of the legs 38, 39 on the one hand to the side supports 12 and 13 and on the other hand to the hinge joint in the main cross member 34, via which the legs 38, 39 are connected. To reduce the play of the swivel axes, a feed device is provided according to the invention, with which the legs 38, 39 can be moved towards each other to the longitudinal center plane of the wheelchair 10 .

In the following the structural design and the mode of operation are shown in Figs 2 - 5 described infeed illustrated for the right side of the wheelchair 10 in more detail.. One recognizes an approximately rectangular opening 72 which is arranged in the wheel carrier 14 and which extends over steps 72a, 72b, 72c between the inner surface and the outer surface of the wheel carrier 14 . The opening 72 is closed by means of a cover plate 78 accommodated in the step 72a , which is rigidly connected to the wheel carrier 14 by means of screws (not shown) for which four bores 80 are provided. Within the vertical cover plate 78 is located in the opening 72 a in the next succeeding stage 72b disposed plate 82 with an integrally formed at their Zustellkörper 84. The plate 82 and the Zustellkörper 84 is acted upon by an adjusting screw 86 which is screwed in the cover plate 78, , As a result, the feed body 84 presses the bearing body 40 of the right leg 38 lying against it to the left or to the leg 39 or to the center of the wheelchair 10. A corresponding feed device is also provided in the left wheel carrier 14 , with the difference that there is that of the set screw 86 corresponding set screw and the feed body corresponding to the feed body 84 are arranged in the upper area of the opening, while the set screw 86 and the feed body 84 in the illustrated right feed device are in the lower area of the opening 72 . The reason for this asymmetrical design of the rest of the symmetrical feed devices is that the set screw 86 of the right feed device should be aligned with the longitudinal axis of the right leg 38 of the main cross member 34 so that the feed takes place in an efficient manner. Since the left leg 39 of the main cross member 34 lies above the right leg 38 , the left infeed device is consequently also located higher up than the right infeed device, so that in each case the infeed screw is aligned with the longitudinal axis of its leg. Nevertheless, identical openings, cover plates and plates with molded-on delivery body can be used for the left and the right delivery device, the upper edges of the cover plate and the plate in the left delivery device being arranged at the bottom in the right delivery body.

Claims (14)

1. A folding wheelchair (10) having two lateral supports (12, 13), to each of which a drive wheel (19) and a running wheel (20, 21) are attached, and which are rigidly connected by a horizontal main cross-bar (34) and an additional cross-bar, the main cross-bar (34) being formed by two members (38, 39) which are linked to the lateral supports (12, 13) and are connected by way of a hinged joint and detachably locked in relation to one another by means of a locking device having a stop face (62) and a locking element (56), in which

   the members (38, 39) come into contact with one another in an area of contact (38o, 39u)

   and at least one of the members (38) can be adjusted parallel to the rotational axis of the drive wheels (19) by means of a positioning mechanism (72, 82, 84, 86),

   characterized in that

   the locking element consists of a locking projection (56) and is pivot-mounted on one of the members (38), and

   the stop face (62) consists of a part of a long stop zone (64), which extends substantially parallel to the rotational axis of the drive wheels (19), is located opposite the locking projection (58) and is disposed on the other one of the two members (39).
2. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the two members (38, 39) are disposed substantially at right angles to the main cross-bar (34).
3. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the other one of the two members (39, 38) also has a positioning mechanism.
4. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the positioning mechanism has an adjusting element (84) which acts on the member (38) and can be displaced relative to the lateral support (13).
5. A folding wheelchair (10) according to Patent Claim 4,
   characterized in that
   the adjusting element (84) is infinitely displaceable by means of a wedge- or spiral-shaped adjusting element (86).
6. A folding wheelchair (10) according to Patent Claim 4,
   characterized in that
   the adjusting element (84) is accommodated in an opening (72) of an extension (14) of the lateral support (12, 13), said opening (72) being covered by a coverplate (78) which is rigidly fixed to the extension (14) and in which the adjusting element (86)) is received.
7. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the stop zone (64) is preferably a flat outer face (39v) of one of the members (39), said outer face (39v) being oriented parallel to the rotational axis of the drive wheels (18, 19).
8. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the locking projection (56) is pivoted on a locking pin (60) disposed in one of the members (38) and extending in longitudinal direction of the member (38).
9. A folding wheelchair (10) according to Patent Claim 1,
   characterized in that
   the locking projection (56) is prestressed on the stop face (62).
10. A folding wheelchair (10) according to Patent Claim 1,
    characterized in that
    at least one of the members (38) has a plurality of holes (46a ― 46e) distributed at a distance from one another over its length, one of these holes (46c) selectively being located so as to be in alignment with a hole (47a) of the other member (39) to adjust the length of the main cross-bar (34).
11. A folding wheelchair (10) according to Patent Claim 1,
    characterized in that,
    for precision adjustment of the play of the hinge pin (44), an adjusting nut (48) is provided in the hinged joint connecting the members (38, 39), said nut (48) being secured in its ideal position by means of a securing device (50).
12. A folding wheelchair (10) according to Patent Claim 1,
    characterized in that
    the swivel pins, about which the members (38, 39) of the main cross-bar (34) swivel, are disposed vertically.
13. A folding wheelchair (10) according to Patent Claim 1,
    characterized in that
    the main cross-bar (34) connects central areas of horizontal arms (12a, 13a) of the longitudinal supports (12, 13), so that the main cross-bar (34) is disposed underneath the centroidal axis of the folding wheelchair (10) when it is occupied.
14. A folding wheelchair (10) according to Patent Claim 1,
    characterized in that
    the locking mechanism is designed so that it can be operated with one hand.

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