EP0754441A2 - 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 collapsible wheelchair according to the preamble of claim 1.

Foldable or foldable wheelchairs of this type have been known for a long time. A need for this arose above all with the advent of automobiles, which are more suitable for covering longer distances than wheelchairs, but for which numerous places, in particular living spaces, workplaces and public buildings, are not accessible, so that there was a desire to collapse them to small dimensions Carrying a wheelchair in an automobile and using it when open when necessary. Such wheelchairs are subject to numerous requirements, some of which are contradictory in terms of their construction. In addition to the properties that non-collapsible wheelchairs must also have, low-weight wheelchairs, in particular sufficient stability during use and simple handling when folding are desirable. it is also advantageous to design the folding wheelchair in such a way that it turns out to be 'hard', ie completely free of play and rigid, or 'soft', depending on your needs.

In terms of weight, satisfactory results can be achieved by following the general principles of lightweight construction, both in terms of shape and in the selection of the materials used.

In terms of stability, there is a significant advance over the traditional folding wheelchairs, which were a kind of director's chair with wheels, by using a closed frame. Such a frame consists essentially of two in the longitudinal direction, i.e. side beams running in the direction of travel of the wheelchair, which are connected by two cross beams running transversely to the direction of travel. One of the large drive wheels is attached to the side carriers in the rear, upper area and one of the very small wheels in the front, lower area. The side supports are 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. The cross members connect the side members, a main cross member being arranged under the seat surface and a secondary cross member being formed by the footrest and its fastening device. In order for the frame to be rigid, the connections of the longitudinal and cross members must be as free of play as possible.

The foldability of the wheelchair comes about because the cross members, which determine the distance between the side members in the operating state, can be folded relative to the side members into a position in which this distance is as small as possible is. So that the folding wheelchairs can also be easily handled by the disabled, the cross members, which are brought into a different position during the folding process, must be able to be moved relative to one another and relative to the side longitudinal members in a simple manner. This means that the necessary game is available.

It can be seen from this that a core problem in the construction of folding wheelchairs is to design the components that are movable relative to one another so that they can be folded in such a way that they can be locked to one another with as little play as possible in the operating position and can be moved against one another as smoothly as possible when folded. In addition, a frame that is as "rigid" as possible must be provided, so that the running and driving behavior can be optimally designed.

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 previously known folding wheelchair is that either its stability in use is insufficient or that it cannot be folded easily; the hinge joint, which connects the two legs of the main crossmember, either has play, which means that it is easy enough to fold but not stable, or it is free of play, which then gives sufficient stability, but not easy-to-move. A further consequence of this arrangement is that the folding chair in use is either 'soft' if there is play or 'hard' if there is no play, but in this respect does not adapt to the wishes and needs of the user leaves. There is a possibility of such a soft / hard setting; however, it must already take place during the assembly of the folding wheelchair, its change accordingly a partial disassembly of the folding wheelchair and can therefore not be easily accomplished by the user or another layperson.

A further disadvantage of the aforementioned known folding wheelchair is seen in the fact that both legs extend over the entire wheelchair width, one leg being arranged in a slot-like longitudinal recess in the other leg, so that the legs touch in two separate, parallel contact planes. This construction, which is relatively heavy due to the wide legs, was probably chosen in the incorrect assumption that the stability should be increased by the legs not only touching one another in the operating position but in two contact levels and also across the entire width of the folding wheelchair. However, so that the foldability is not obstructed too much, there must be some, albeit minimal, play between the outer leg parts of one leg and the other leg arranged on the inside; the legs cannot therefore be pressed against one another by the locking device in such a way that they simultaneously touch in a force-transmitting manner along two opposite contact planes. In addition, because the locking device is unsuitable for pressing the legs against one another in at least one of the possible contact planes, the middle leg will have a tendency to oscillate back and forth between the surfaces of the other leg that delimit the recess, which of course has a negative effect on the stability.

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 a locking surface which is formed by bores in the legs, which are aligned in the operating position, and a locking body in the form of a locking bolt which is received in the aligned bores in the locking position. The proportionate weakly designed locking bolts are subject to considerable transverse forces, through which it is plastically deformed. When folding the folding wheelchair, the release of the locking device and then the actual folding process must take place. To release the locking, the locking bolt mentioned must be pulled out of the aligned holes by a precise, linear movement. The execution of such a movement is anyway not easy and is made more difficult by the fact that no ergonomically favorable or at least sufficiently large handle is provided, which can be grasped by hand when the locking bolt is actuated. The pulling out of the locking bolt is also made more difficult by the plastic deformation described above. Carrying out the actual folding process also proves to be difficult because there is no contact surface which is intended and suitable for gripping when folded manually. Unfolding and making the folding wheelchair ready for operation is even more difficult, since the legs have to be brought into a position in which the holes are exactly aligned, which is not easy, on the one hand due to the play of the hinge joints which connect the legs to one another and to the side supports, and on the other hand, because practically no visual inspection is possible. Even if the legs can be brought into a position in which the bores are really aligned and the legs can also be held in this position, the linear insertion of the locking bolt proves to be difficult due to the small opening which has to be exactly hit , the insertion movement, which must be exactly linear so that the locking pin does not jam, and as a result of the deformation of the locking pin, which has already been mentioned several times.

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 both in the operating position and easy to operate when folded and unfolded and a simple hard / soft Adjustability offers.

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 the subclaims.

The new folding wheelchair differs from the previously known folding wheelchair according to the prior art by several features, which features bring about the solution of the task according to the invention in combination. These features are firstly the deliverability of at least one of the legs of the main crossmember, which is parallel to the axis of the main crossmember, parallel to the wheel axis, secondly the legs of the main crossmember which only touch each other along one contact surface, and thirdly the elongated design of the latching surface directed transversely to the movement of the locking body, in which the locking body on one any can run up. The effects achieved with these three features are detailed below.

As mentioned, the first feature according to the invention of the new folding wheelchair relates to the deliverability of at least one of the legs of the main cross member running at right angles to the main cross member in the direction of the longitudinal center surface of the folding wheel chair; With such an infeed, the play of the hinge joints between the side members and the main cross member and between the legs of the main cross member can be eliminated. This increases both the stability of the folding wheelchair in its operating position and its easy foldability. The improvement in stability by avoiding the game is obvious and requires no further explanation; the ease of folding is achieved by the fact that the play of the hinge axes can be chosen relatively generously, precisely because there is the possibility of lifting this play in the operating position by the infeed of the legs. It is also important that the folding wheelchair by choosing the extent of the infeed between a minimum and a maximum value from 'soft' to 'hard', the rigidity of the closed frame is less with the 'soft' folding wheelchair than with the play-free and therefore 'hard' folding wheelchair. In contrast to the pre-setting on the assembly side of the known folding wheelchair, such a setting in the wheelchair according to the invention is easily possible by the user himself, which enables him to adapt his folding wheelchair to the respective terrain or other needs by changing the setting mentioned. The addition of the legs of the main cross member makes it possible to compensate for wear-related play.

The second feature of the invention relates to the design and arrangement of the legs of the main cross member. In contrast to the legs of the known folding wheelchair, the legs of the main crossmember of the folding wheelchair according to the invention only overlap in a central region where they touch only one contact plane in the operating position or in the locked state and are arranged at right angles to the main crossmember. By releasing the locking device, the mutual pressing of the contact surfaces of the overlapping regions of the two legs is eliminated, so that, due to the absence of frictional forces, the two legs can be pivoted easily against one another without any effort. It is easy to see that this arrangement facilitates foldability; it is less obvious that at the same time the stability in the operating position is increased, which is to be explained below. In the previously known wheelchair, as already described, the legs are designed such that their mutual contact should take place in two contact levels; however, as explained above, such double contact cannot occur, so that the desired stability is not achieved. In contrast to this, with the design according to the invention, the legs, which touch in only one contact plane, are achieved by 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 the disadvantages in this respect that the previously known folding wheelchair has are avoided. The latching surface is elongated and directed transversely to the movement of the locking body, and the locking body can run onto the latching surface at any point thereof. Any play that is provided or that has arisen due to wear and that influences the relative position of the two legs in their longitudinal direction, that is to say transversely to the direction of travel of the folding wheelchair, does not therefore make it more difficult to actuate the locking device. This to a certain extent location-independent locking can be attributed to the fact that the advantageous possibilities of the delivery of the legs described above can be fully utilized, in particular also to make the folding wheelchair 'hard' or 'soft' as required, whereby the relative position of the legs changes becomes. Another advantage of the new locking device is that the locking body, which is designed as a locking lug, is designed to be pivotable and can be pivoted toward the locking surface or away from it; such a pivoting movement can be carried out much more easily than the linear sliding or pulling movement which is necessary for actuating the locking bolt according to the prior art. A spring device tensions the locking lug, or the lever device on which the locking lug is arranged, towards the locking position. In addition, a large handle is provided, which facilitates the actuation of the lever device of the locking nose and therefore also contributes to the easier implementation of the folding and unfolding. Finally, in contrast to the weak locking bolt of the previously known folding wheelchair, which is actually only suitable for positioning the legs, the locking device of the folding wheelchair according to the invention is of solid construction and it is therefore enables the legs to be pressed together in such a way that high stability is guaranteed.

In addition, the one-hand folding operation is provided, which results in a further considerable operating advantage.

In summary, it can thus be stated that the folding wheelchair according to the invention advantageously differs from the previously known folding wheelchair both in terms of its stability in use and in terms of its comfortable foldability. The advantages sought by the infeed carried out transversely to the direction of travel can be achieved if an infeed device is provided for one of the two legs. In view of the very small distances over which such delivery devices have their effect, and for generating a symmetrical delivery, it is advantageous to provide delivery devices for both legs.

The infeed devices can be designed such that they have an infeed body which acts on the leg transversely to the direction of travel or in the longitudinal direction by being displaceable relative to the side support to which the leg is articulated.

Advantageously, the deliverability is infinitely variable in that the delivery body can be displaced over a wedge-shaped or helical surface by means of an delivery element.

In a preferred exemplary embodiment, the infeed body is received in an opening in a plate-shaped extension of the side carrier which is arranged in the direction of travel, its surface facing the leg abutting the latter. The opening is closed on the outside or on the side facing away from the leg by a cover plate rigidly attached to the attachment. The feed element in the form of a screw or an eccentric disc is rotatably received in this cover plate.

According to the invention, the latching area is arranged on a surface of one of the legs extending in the direction of infeed, the portion of the latching area opposite the locking nose, on which the locking nose runs, acting as the actual latching area. Since the locking lug always finds a suitable locking surface, so to speak, regardless of location, it is not necessary to provide an adjustment option for the locking device in order to adjust the extent of the delivery of the legs or the selected setting of the leg length, which will be discussed further below. adapt locally. Usually a mostly flat outer surface of the leg is used as the rest area.

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

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

It has already been mentioned that the length of the main crossbeam is adjustable, which means that the width of the folding wheelchair can be changed with the purpose of adapting it to the needs of its users. If the two legs of the main cross member are not over the entire width of the Folding wheelchair extend, so they overlap with their ends arranged in the region of the longitudinal center plane of the folding wheelchair, this overlap area being greatest when a minimum width is desired and decreasing when larger widths are set. The adjustment of the width is not infinitely variable, since this would require a complex telescopically extendable device on at least one of the cross members, and an adjustment in sufficiently small steps or steps can also be effected by other means, as will be described in the following. Of the two legs, which are connected to one another via a hinge joint, at least one has not only one bore for receiving the hinge axis, but also a plurality of axially parallel bores. These bores are spaced apart from one another over an area of the leg intended to overlap with the other leg. Optionally, one of the holes is aligned with the hole of the other leg and a bolt is inserted into the hinge axis. It is obvious that the number of setting options is increased if the second leg also has a large number of bores which are not to be arranged at the same distance as the bores in the first leg.

A device with an adjusting nut is advantageously used to fine-tune the play of the hinge axis. Since this tends to shift and even loosen as a result of numerous folding processes which the hinge joint suffers, a securing device is advantageously provided in order to fix the adjusting nut in its desired position. For example, an adjusting nut can be selected which is secured in a known manner with a threaded pin which is parallel to it and which engages in one of the concavities of the adjusting nut.

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 swiveling movements around horizontal swivel 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 favorable 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 located there under the rear area of the seat, 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 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 linken 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. 3;

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 linken 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 hinten;

Fig. 7

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

Fig. 8

den rechten 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 mit nicht dargestellter Einhandbetätigungs-Vorrichtung; 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 - partly schematic - representation, in a diagram;

Fig. 2

a part of a left side carrier 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

. in Figs 1 - 2 side support shown in a section along the line 4 - 4 of FIG. 3;

Fig. 5

the parts of the delivery device arranged in the side carrier of FIGS. 2-4, namely the one section of the side carrier, the delivery body and the cover plate and the left leg of the main cross member, simplified, in an exploded view, in a diagram;

Fig. 6

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

Fig. 7

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

Fig. 8

the right 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 with a hand-operated device, not shown; and

Fig. 10

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

It should be said that the folding wheelchair is described in the opened state, i.e. in the operating state, and that information such as 'above', 'below', 'left', 'right', 'front', 'behind' always refer to one horizontal folding wheelchair, which is seen in the direction of travel.

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 supports 12, 13 are approximately L-shaped and each have a horizontal arm 12a, 13a and an arm 12b, 13b pointing obliquely forward and downward.

The horizontal arm 12a of the left side carrier 12 has in its rear region a vertical plate-like extension, which is referred to as a wheel carrier 14 , and to which a drive wheel 18 is fastened via an adapter plate 16 ; In a symmetrical arrangement, a drive wheel 19 is fastened to a shoulder 15 of the right side support 13 via a further adapter plate 17 .

Both the wheel carriers 14, 15 and the adapter plates 16, 17 have a large number of bores. This gives numerous possibilities to attach the adapter plates 16, 17 to the wheel carriers 14, 15 on the one hand and the drive wheels 18, 19 to the adapter plates 16, 17 on the other hand, so that the wheelchair 10 with its geometry meets the needs of different users and is possibly adaptable to changing needs of a particular user.

The drive wheels 18, 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 does a lot can be lifted and supplied more easily.

At the lowest area of the inclined arms 12b, 13b , impellers 20, 21 are fastened in a conventional manner, the diameter of which is significantly smaller than the diameter of the drive wheels 18, 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 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 32 and a main cross beam 34 , whereby a closed, relatively rigid frame is formed. The secondary cross member 32 is located at the level of the lower ends of the inclined arms 12b, 13b of the side supports 12, 13 and is combined in the usual way with a footrest 36 which is designed to be foldable. The main cross member 32 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 consists essentially of FIGS. 6-8 of two legs 38, 39 hinged almost at right angles . The left leg 38 has a bearing body 40 for receiving a vertical pivot axis, not shown, via which it is articulated on the left wheel carrier 14 and is thereby indirectly attached to the left side carrier 12 ; Correspondingly, the right leg 39 has a bearing body 41 for receiving a pivot axis, also not shown, via which it is articulated on the right wheel carrier 15 and is thus indirectly attached to the right side carrier 13 . 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 center surface of the wheelchair.

The right leg 39 lies with its lower surface 39u on the upper surface 38o of the left leg 38 , so that the surfaces 38o, 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 can be pivoted relative to one another about a vertical hinge axis 44 from their parallel position, which they assume in the operating state of the wheelchair 10 , into a rest position, not shown, that they take 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 cross member 32 and the main cross member 34 is formed so that its length is selectively variable, wherein for adjustment of the auxiliary transverse beam 32 conventional and therefore not described further constructional measures are provided. 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 46b, 47b . 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 FIGS. 6-8. For this purpose, a locking device is provided, in which, in the locked state, a locking body bears against a locking surface under the action of a fixing element. In the present wheelchair 10 , the locking body is formed by a locking nose 56 arranged on a lever device 54 . The lever device 54 is articulated on a shoulder 58 of the left leg 38 and can be pivoted about a horizontal locking axis 60 . The one that interacts with the locking nose 56 in the locked state The latching surface 62 is formed by a section of an elongated latching region 64 opposite the locking lug 56 , which extends along the rear vertical side surface 39h of the right leg 39 . The latching surface 62 and the latching area 64 are indicated in FIG. 9 with dashed 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. The locking lug 56 is prestressed onto the respective latching surface 62 by means of a spring device 68 shown in FIG. 9 . In the assembled state, the spring device 68 is received in a recess in the left leg 38, which is not shown in FIG. 9 . On the other hand, clearly recognizable in FIG. 9 is an ergonomically favorable handle 70 with which the locking device can be actuated in a simple manner. This handle can also advantageously be designed as a so-called one-hand operation of the folding device, for the sake of clarity.

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 nose 56, depending on the set width of the wheelchair 10 and depending on the delivery of the legs 38, 39, which will be discussed later, assume a variable position along the width of the wheelchair 10 over a certain distance can. It is also pointed out that the lower rear edge of the right leg 39 has a slope 39s which is at least approximately the same inclination as the forward and downward slope 56s of the locking lance 56. This is achieved, firstly, that there are no fitting problems between the right leg 39 and the shoulder 58 of the left leg 38 , and second that when unfolded of the wheelchair 10, the locking nose 56 with its bevel 56s comes into contact with the bevel 39s of the leg 39 , which facilitates the pivoting of the lever device 54 in the clockwise direction in FIG. 9 , which must be carried out for the mutual locking of the legs 38, 39 .

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 opposite demands are made 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, by means of 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 feed device shown for the left side of the wheelchair 10 in more detail.. One recognizes an approximately rectangular aperture 72 arranged in the wheel carrier 14 , which extends over two steps 72a, 72b between the inner surface 74 and the outer surface 76 of the wheel carrier 14 . The opening 72 is closed by means of a cover plate 78 resting on the step 72a , which is rigidly connected to the wheel carrier 14 with screws, not shown, for which four bores 80 are provided. Within the vertical cover plate 78 there is in the opening 72 a plate 82 resting on the next step 72b with a molded on it Infeed body 84. The plate 82 or the infeed body 84 is acted upon by an adjusting screw 86 which is screwed into the cover plate 78 . As a result, the feed body 84 presses the bearing body 40 of the left leg 38 lying against it to the right or to the leg 39 or to the center of the wheelchair 10. A corresponding feed device is also provided in the right wheel carrier 15 , 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 region of the opening, while the set screw 86 and the feed body 84 in the illustrated left feed device are in the lower region of the opening 72 . The reason for this asymmetrical design of the rest of the symmetrical feed devices is that the adjusting screw 84 of the left feed device should be aligned with the longitudinal axis of the left leg 38 of the main cross member 34 so that the feed takes place in an efficient manner. Since the right leg 39 of the main cross member 34 lies above the left leg 38 , the right infeed device is consequently also located higher up than the left infeed device, so that the infeed screw is always 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 right delivery devices, the upper edges of the cover plate and the plate with the delivery body being arranged in the right delivery body at the bottom in the left delivery device.

Claims (14)

Folding wheelchair (10) with two side beams (12, 13) , to each of which a drive wheel (18, 19) and a wheel (20, 21) are fastened, and which by a horizontal main cross member (34) and a secondary cross member (32) are rigidly connected, the main cross member (34) being formed by two legs (38, 39 ) articulated on the side members (12, 13) , which are connected via a hinge joint and by means of a locking surface (62) and a locking body (56) Locking device are mutually lockable,
characterized,
that at least one of the legs (38 , 39u), each contacting a contact surface (38o, 39u), can be adjusted by means of an infeed device parallel to the axis of rotation of the drive wheels (18, 19) , and that one of the legs (38) acts as a pivotable locking lug (56) has formed locking body, while the other leg (39) has an elongated locking area (64) extending in the feed direction, of which locking area (64) a section opposite the locking nose forms the locking surface (62) . Folding wheelchair (10) according to claim 1,
characterized,
that the two legs (38, 39) are arranged substantially at right angles to the main cross member (34) . Folding wheelchair (10) according to claim 1,
characterized,
that the other of the legs (38, 39) also has an infeed device. Folding wheelchair (10) according to claim 1,
characterized,
that the infeed device has an infeed body (84) which acts on the leg (38, 39) and which can be displaced relative to the side carrier (12, 13) . Folding wheelchair (10) according to claim 4,
characterized,
that the feed body (84) can be moved continuously by means of a wedge-shaped or helical feed element (86) . Folding wheelchair (10) according to claim 4,
characterized,
that the infeed body (84) is received in an opening (72) in an extension (14, 15) of the side support (12, 13) , which opening ( 72) is covered by a cover plate (78) rigidly attached to the extension ( 14, 15) in which the feed element (86) is received. Folding wheelchair (10) according to claim 1,
characterized,
that the latching area (64) is a preferably flat outer surface (39v) parallel to the axis of rotation of the drive wheels (18, 19) and is one of the legs (39) . Folding wheelchair (10) according to claim 1,
characterized,
that the locking lug (56) is articulated on a locking axis (60) arranged in one of the legs (38) and extending in the longitudinal direction of the leg (39) . Folding wheelchair (10) according to claim 1,
characterized,
that the locking lug (56) is biased onto the locking surface (62) . Folding wheelchair (10) according to claim 1,
characterized,
that at least one of the legs (38) has a plurality of bores (46a - 46e) spaced apart over its length, of which one bore (46c) can optionally be aligned with a bore (47c) of the other leg (39) so that the Adjust the length of the main cross member (34) . Folding wheelchair (10) according to claim 1,
characterized,
that for adjusting the play of the hinge axis (44) in the hinge joint connecting the legs (38, 39) , an adjusting nut (48) is arranged, which can be secured in its desired position by means of a securing device (50) . Folding wheelchair (10) according to claim 1,
characterized,
that the pivot axes about which the legs (38, 39) of the main cross member (34) are pivotable are directed vertically. Folding wheelchair (19) according to claim 1,
characterized,
that the main cross member (34) connects central areas of horizontal arms (12a, 13a) of the longitudinal members (12, 13) so that the main cross member is arranged below the center of gravity of the loaded folding wheelchair (10) . Folding wheelchair (10) according to claim 1,
characterized,
that the two legs (38, 39) can be fixed by a one-hand locking device.

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