EP2532335A2 - Cross brace assembly for a wheelchair - Google Patents

Abstract

The invention relates to a crossbar assembly for a wheelchair, in particular folding wheelchair, comprising a cross strut with a first cross strut member and a second cross strut member, wherein the first cross strut member and the second cross strut member are pivotally mounted to each other by means of a pivot bearing, wherein the pivot bearing further comprises a sliding sleeve for rotatably receiving at least one of the cross strut elements, and a wheelchair comprising a cross strut assembly according to the invention.

Description

The invention relates to a crossbar assembly for a wheelchair, in particular folding wheelchair, comprising a cross strut with at least a first cross strut element and at least a second cross strut element, wherein the first cross strut element, the second cross strut element by means of a first axis of rotation having first pivot bearing are mounted to each other pivotally.

Wheelchairs are known in practice, which have two side frames, on each of which a rear wheel and a front wheel of the wheelchair is accommodated. The backrest and the seat surface of the wheelchair are arranged in a region between the side frames, wherein the side frames are connected to stabilize the wheelchair by means of a cross strut, which is usually arranged in the region below the seat.

To be able to reduce the space occupied by an unused wheelchair space, for example, for transport purposes, so-called folding wheelchairs are also known, which make it possible to move the side frames of the wheelchair as close as possible to each other, the seat and back in a folded or folded state be transferred. For example, the US4,813,693 discloses a generic crossbar assembly. For this purpose, the cross strut on at least two scissor-like pivotally interconnected cross strut elements by means of a first pivot bearing. This allows a guided by the cross strut displacement movement of the side frames toward each other, wherein the wheelchair is folded in total so that the side frames in a substantially parallel arrangement can be brought to each other with reduced distance. The folding wheelchair is operational only in its fully unfolded position and has only in this position a mediated by the cross strut, sufficient mechanical stability, while each folded position is mechanically unstable and does not allow use of the folding wheelchair.

The cross strut members, which are usually pivotally connected to the side frames at at least one first end, preferably via at least one second pivot bearing, are exposed to various forces when using the wheelchair. In particular, the cross strut elements are subjected to bending forces, torsional forces and / or compressive forces in the region of the first pivot bearing pivotally connecting them. For this reason, both the cross strut elements and the first pivot bearing must have a sufficiently high mechanical stability, which disadvantageously leads to a high weight in previously known cross strut assembly. In particular, it is known to provide for the formation of particularly stable cross brace assemblies more than two cross strut elements, for example, three or four cross strut elements, of which at least two are arranged parallel to each other and are all pivotally connected together in a common first pivot bearing. The cross strut thus formed disadvantageously has a high weight and is expensive to manufacture due to the high number of cross strut elements.

Known pivot bearing for cross strut elements have a pin or bearing pin, which is received in alignment with each other arranged mounting holes of the cross strut elements and forms a first axis of rotation of the first pivot bearing. The cross strut elements are each rotatably received on the pin. The fastening holes provided in the cross strut elements constitute a weakening of the cross strut elements with respect to mechanical loads. The contact surface between the bearing bolt and the cross strut element is only small, so that disadvantageously high pressures are transmitted between the cross strut element and the bearing bolt, which leads to a high mechanical load. In particular, the pin or bolt is only punctually loaded, so that it comes due to overuse in this area to a malfunction, such as a breaking of the pin.

It is the object of the invention to provide a crossbar assembly which has a high mechanical stability with low weight.

This object is achieved in that the first pivot bearing has at least one sliding sleeve for relative to the sliding sleeve rotatable receptacle of the first cross strut element and / or the second cross strut element. A pivoting movement of the at least one cross strut element is achieved by turning relative to the sliding sleeve or the other cross strut element. The other cross strut element can be fixed or movable, preferably rotatable, relative to the sliding sleeve. Under a sliding sleeve in the context of the invention is understood in comparison to a pen larger diameter exhibiting bearing element, which is in particular part of a sliding bearing, has a cylinder jacket-shaped support structure, preferably formed as a hollow cylinder, and / or an element such stores that substantially uniformly distributed over the circumference and / or an axial extent along the axis of rotation of the sliding sleeve, a contact with the element to be stored is, in particular via a press fit. Thus, the sliding sleeve may have a cylindrical jacket-shaped support structure, which are filled with a substantially no load-bearing material to achieve a high stability with low weight.

Preferably, the first cross-strut element and the second cross-strut element are respectively rotatably received on the sliding sleeve, in particular about the first axis of rotation. This offers the advantage that the pivot bearing with respect to the first cross member and the second cross strut element can be constructed completely symmetrical to avoid a different mechanical load of the first cross member or the second cross member and / or the first pivot bearing. This further offers the advantage that, in particular in a releasable connection of the cross strut elements with the sliding sleeve indiscriminately both the one and the other cross strut element can be selectively released from the sliding sleeve, which in particular simplifies setting or replacement of components of the wheelchair.

Preferably, at least one outer peripheral portion of the sliding sleeve is designed as a sliding surface. Particularly preferably, the sliding surface encloses the sliding sleeve completely circumferentially, which advantageously allows a complete circular movement of the cross-strut element to the sliding sleeve.

Most preferably, it is provided that the sliding sleeve comprises at least two sliding surfaces, and that the sliding surfaces, in particular with respect to the first axis of rotation, are axially spaced from each other. Suitably, each of the sliding surfaces is assigned in each case one of the cross strut elements in order to allow a storage of the respective cross strut element. It is understood that a cross brace assembly according to the invention can also have more than two cross strut elements, for example, three or four cross strut elements, in which case the sliding sleeve preferably has a corresponding number of sliding surfaces and each of the sliding surfaces is assigned to exactly one cross strut element. In such a cross brace assembly expediently at least two of the cross brace elements may be arranged parallel to each other to jointly allow a power transmission between connected elements, such as the side frame or a seat of the wheelchair.

In a preferred refinement of the crossbar arrangement, the sliding sleeve, in particular in a receiving region for the first crossbar element and / or the second crossbar element, has a first extent in an axial direction of the first axis of rotation, in particular an outer circumference with a first cross sectional diameter, and a second extent into one Direction perpendicular to the first axis of rotation, in particular an outer circumference with a second cross-sectional diameter, wherein the first cross strut element and / or the second cross strut element at least partially, in particular outside the range of the first pivot bearing and / or as a tube, with a third extension parallel to the first axis of rotation, in particular a third cross-sectional diameter, and a fourth dimension perpendicular to the first axis of rotation, in particular a fourth cross-sectional diameter, is formed, and wherein the second dimension is greater than the third A and / or the fourth extent and / or the first extent is substantially equal to or less than the third extent. This design of the sliding sleeve with a particularly large cross-sectional diameter in a direction perpendicular to the first axis of rotation causes a particularly high mechanical stability, since a support surface of the cross member on the sliding sleeve is particularly large and acting forces such as bending forces, torsional forces and / or compressive forces on the support surface easy are transferable to the sliding sleeve, without exceeding a maximum permissible pressure load for the material of the cross strut elements and / or the sliding sleeve.

Preferably, at least one holding element is provided for, in particular with respect to the first axis of rotation, axial fixing of the first crossbar element and / or of the second crossbar element on the sliding sleeve. The retaining element restricts axial movability of the crossbar element relative to the sliding sleeve in such a way that the crossbar elements are held securely on the sliding sleeve in the axial direction of the sliding sleeve or in the axial direction of the first axis of rotation of the first pivot bearing or of the crossbar element about the sliding sleeve, a rotational movement However, the cross strut member is not limited to the sliding sleeve.

Particularly preferably, at least two holding elements are provided which limit the sliding sleeve in, in particular with respect to the first axis of rotation, axial direction. In particular, in cross brace assemblies in which at least two cross strut elements are each provided rotatably to the sliding sleeve, each one of the holding elements serves to limit the mobility of all cross strut elements in one of the axial directions of the axis of rotation. In cross brace assemblies comprising two or more to the sliding sleeve rotatable cross strut elements may further be provided that each spacer elements are arranged between the cross strut elements, for example in the form of a survey of the peripheral surface of the sliding sleeve between two adjacent sliding surfaces, on the one hand a minimum axial distance of the cross strut elements to define each other and on the other hand to prevent or reduce collisions or frictional forces in the region of the pivot bearing between the crossbar elements.

In an expedient embodiment, it is provided that the retaining element can be fastened to the sliding sleeve with at least one, preferably a plurality of fastening elements. and that the fastening element is arranged at least in sections in an area enclosed by the sliding sleeve. According to a first preferred embodiment, the fastening elements are designed as releasable fastening elements, for example as screws, wherein the sliding sleeve preferably has a central, preferably continuous and expedient in its axial extension parallel to the first axis of rotation of the cross brace elements opening and in particular in a region within the opening fastening areas are provided, each receiving one of the fasteners. The intended opening contributes to a light weight of the cross brace assembly at the same time excellent mechanical stability. The releasable fasteners allow any time a release of the retaining element of the sliding sleeve, for example, to perform adjustments to the wheelchair or replace a cross strut element. According to a second, likewise preferred embodiment, the fastening elements are provided as permanent, in particular insoluble fastening elements, for example as riveting, Klips-, latching and / or adhesive elements. It is understood that a releasable or permanent attachment by other alternative or complementary fastening methods, in particular a cohesive, non-positive and / or positive fastening, can be achieved, wherein the fasteners as cohesive fasteners such as adhesive or as positive and / or non-positive fastening elements such Mounting projections or recesses, pressing elements and / or gripping elements are formed. It is further understood that the opening of the sliding sleeve can be provided independently of the type or number of fasteners, in particular for weight reduction. It is also understood that it can be dispensed with the provision of an opening of the sliding sleeve, if this is desired, for example, for reasons of stability or design.

It is preferably provided that the first cross-strut element and / or the second cross-strut element has or have at least one bearing element which can be accommodated on the sliding sleeve. The bearing element can be formed both as an integral, in particular insoluble, component of the cross strut element as well as a detachable from the cross strut element component. The bearing element is expedient both for Forming a low-friction bearing pair with the sliding sleeve as well as the stable mechanical connection with the cross strut element formed.

Particularly preferably, the bearing element has an opening with an inner diameter adapted to an outer diameter, the sliding sleeve, in particular the second extension. The bearing element is thus by inserting the sliding sleeve in the opening of the bearing element, in particular by a press fit, on this storable.

Most preferably, the bearing element has an at least inner sliding surface, which is designed to form a sliding pair with the sliding sleeve and / or rests on the sliding sleeve as a press fit. Suitably, a material is at least the inner sliding surface of the bearing element selected such that only a small friction between the bearing element and sliding sleeve is formed. In an alternative, likewise preferred embodiment, a bearing of the bearing element on the sliding sleeve can be provided by further bearing elements, for example by the provision of a ball or roller bearing.

It is expediently provided that the bearing element for forming the first cross strut element and / or the second cross strut element with at least one cross strut member connectable, preferably releasably connectable, is. Particularly preferably, a cross strut element comprises two cross strut components, which can each be connected to the bearing element for joint formation of the cross strut element. This advantageously allows the use of standardized bearing sleeves and / or bearing elements for different types of wheelchairs or different cross brace assemblies, in which only the connection with the side frames, seat elements, seat tubes or similar producing cross brace components have specific, adapted to the particular wheelchair properties or characteristics.

According to a preferred embodiment, the first cross strut element and / or the second cross strut element is or can be connected or connected to at least one second rotary bearing for rotatable mounting on at least one side frame of the wheelchair and / or at least one seat tube of the wheelchair. When the cross strut element of a Bearing element and at least one cross strut component, a connectivity to the side frame and / or seat tube is advantageously provided on the cross strut member. It is understood that instead of a complete second pivot bearing for connecting the cross-strut element to the side frame, only one pivot bearing part can be provided for common formation of a second pivot bearing with further, in particular the side frame associated pivot bearing parts.

According to the invention, a wheelchair, in particular folding wheelchair, is further provided with a crossbar arrangement according to the invention.

Thus, the invention is based on the surprising finding that a crossbar assembly with particularly high mechanical stability and at the same time only light weight can be created by providing a sliding sleeve instead of a pin or bearing pin forming the axis of rotation which preferably has a particularly large cross-sectional diameter the respective cross strut elements are rotatably received. It proves to be a particular advantage that the sliding sleeve due to their circular shape can dissipate forces well and has a particularly high contact surface for the cross strut elements, so that despite the larger volume compared to a pen weight and also stability advantages can be achieved. A weight reduction can be achieved in particular in that the sliding sleeve is formed hollow in an inner region, for example by a through opening. This also leads to a surprising, visually appealing design of the cross brace.

Further advantages and features of the invention will become apparent from the following description in which a preferred embodiment of the invention will be explained with reference to the accompanying drawings.

Fig. 1

ein erstes Ausführungsbeispiel einer erfindungsgemäßen Kreuzstrebenanordnung in einer Explosionsdarstellung;

Fig. 2

die Kreuzstrebenanordnung aus Fig. 1 in einer Frontalansicht;

Fig. 3

die Kreuzstrebenanordnung aus Fig. 1 in einer Seitenansicht;

Fig. 4a

eine Gleithülse der Kreuzstrebenanordnung aus Fig. 1 in einer Frontalansicht;

Fig. 4b

die Gleithülse aus Fig. 4a in einer Seitenansicht;

Fig. 5a

ein Lagerelement der Kreuzstrebenanordnung aus Fig. 1 in einer Frontalansicht;

Fig. 5b

das Lagerelement aus Fig. 5a in einer Seitenansicht;

Fig. 6a

ein Halteelement der Kreuzstrebenanordnung aus Fig. 1 in einer Frontalansicht;

Fig. 6b

das Halteelement aus Fig. 6a in einer Seitenansicht.

Show it:

Fig. 1

a first embodiment of a cross brace assembly according to the invention in an exploded view;

Fig. 2

the crossbar arrangement Fig. 1 in a frontal view;

Fig. 3

the crossbar arrangement Fig. 1 in a side view;

Fig. 4a

a sliding sleeve of the cross brace assembly Fig. 1 in a frontal view;

Fig. 4b

the sliding sleeve off Fig. 4a in a side view;

Fig. 5a

a bearing element of the cross brace assembly Fig. 1 in a frontal view;

Fig. 5b

the bearing element Fig. 5a in a side view;

Fig. 6a

a holding element of the cross brace assembly Fig. 1 in a frontal view;

Fig. 6b

the holding element Fig. 6a in a side view.

The cross brace assembly 1 shown in the figures comprises a, in particular a sliding bearing performing, first pivot bearing 2, which connects a first cross strut element 3 and a second cross strut element 4 pivotally together. The cross strut elements 3, 4 are each pivotally received about a first axis of rotation D of the first pivot bearing 2 on a sliding sleeve 5. Each of the cross strut elements 3, 4 has at a first, lower end to a bearing tube 6, which is part of a second pivot bearing and by means of which the respective cross strut element 3, 4 pivotally connected to a side frame of a wheelchair.

As can be seen, the bearing tubes 6 each extend in a direction substantially perpendicular to the extension of the cross strut elements 3, 4, and parallel to the first axis of rotation D, which corresponds to the arrangement of the cross strut assembly 1 on a wheelchair substantially the direction of movement of the wheelchair. The cross strut elements 3, 4 are each connected at its second, upper end fixed to a seat tube 7.

As in particular in Fig. 1 is clearly visible, each of the seat tubes 7 has a longitudinal slot for receiving an edge of a seat surface 11. The seat tubes 7 also extend in a direction substantially perpendicular to the extension of the cross strut elements 3, 4, in particular parallel to the first axis of rotation D, and thus substantially in the direction of movement of the wheelchair. The cross brace assembly 1 is disposed substantially completely below the seat surface 11 of the wheelchair and serves for the mechanical stabilization of the wheelchair. At the same time, the first pivot bearing 2 allows a folding mechanism of the wheelchair: in the operative position of the wheelchair, the seat tubes 7 are supported on the side frames of the wheelchair and weight forces of a seated person acting on the seat 11 are supported by the crossbar assembly 1 between the side frames.

To bring the wheelchair in a folded, space-saving, but not usable for sitting position, the side frames are moved toward each other, the cross strut elements 3, 4 scissor-like about the first axis of rotation D pivoted about the first pivot bearing 2 and the seat tubes 7 along a curved Movement path in an upward direction and moved towards each other. The cross brace assembly 1 and in particular the first pivot bearing 2 is therefore the function to ensure a high mechanical stability and ease Einfaltbarkeit.

How to particular in Fig. 1 clearly recognizes, the cross strut elements 3, 4 are each constructed in three parts and have a centrally disposed bearing element 8 and a first cross strut member 9 and a second cross strut member 10. The first cross brace component 9 is in each case formed integrally with the bearing tube 6 and the second cross brace component 10 is formed integrally with the seat tube 7. The cross strut members 9, 10 are each tubular and formed of a plastic material. In each case one of the bearing tube 6 and the seat tube 7 facing away from the end of the cross brace members 9, 10 has an opening with an expanded cross-sectional diameter, into which a connection portion 19 of a bearing element 8 (see Fig. 5a ) is inserted to connect the cross brace member 9, 10 with the bearing element 8.

How to get into the FIGS. 1 . 4a, 4b recognizes, the sliding sleeve 5 has a substantially cylindrical basic shape and is equipped with the sliding sleeve 5 axially passing through opening 14. The opening 14 serves essentially to reduce the weight of the sliding sleeve 5 without impairing the stability. The sliding sleeve 5 has along its outer circumferential surface two sliding surfaces 16, on each of which an inner surface of an opening 18 of the bearing elements 8 can be accommodated. The cross-sectional diameter of the opening 18 of the bearing elements 8 is adapted to the outer circumference of the sliding sleeve 5. The sliding surface 16 and the inner surface of the opening 18 of the associated bearing element 8 form a sliding pair for the most accurate and simultaneously low-friction and rotatable mounting of the bearing element 8 on the sliding sleeve fifth

Both the bearing element 8 and the sliding sleeve 5 are formed from at least one plastic material that was expedient selected in particular with regard to the material parameters sliding property, mechanical stability, specific gravity or a combination thereof. How to continue in particular in Fig. 2 . 3 and 4b detects, the sliding sleeve, in particular the sliding surface 16, in a direction parallel to the first axis of rotation D, a first extension a ₁ , in particular width and / or a second cross-sectional diameter, and the sliding sleeve 5, in particular the uniform surface 16, in a direction perpendicular to the rotation axis D a second extension a ₂ , in particular an outer second cross-sectional diameter, on. On the other hand, in a region outside the first pivot bearing, in particular in the area of the cross strut component 9, 10, the first and second cross strut elements have a third extension a ₃ in a direction parallel to the first axis of rotation and a fourth extension a ₄ in a direction perpendicular to the first pivot Rotary axis D on. In particular, the second extent a _{2 is} greater than the fourth dimension of the pipe sections of the crossbar members 9, 10. This allows a high mechanical stability of the pivot bearing 2 even with large forces acting on the cross strut elements 3, 4 forces or torques, in particular, since the support surface of the Bearing elements 8 on the sliding sleeve 5 in comparison to conventional pivot bearings with a relatively thin in cross section bearing pin is comparatively large. Furthermore, the first extension a1 is substantially equal to the third expansion a _3, a distance between the Cross struts elements 3, 4 to keep as low as possible, in particular to minimize lever arms and thus bending stresses on the first pivot bearing 2.

The sliding sleeve 5 has centrally along its outer peripheral surface on a survey that forms a spacer 17. The sliding sleeve 5 annularly circulating spacer 17 serves to hold each of the sliding surfaces 16 received on the bearing elements 8 in a defined axial distance along the first axis of rotation D to each other. At the end faces of the sliding sleeve 5, a substantially annular retaining element 12 is arranged in each case, whose diameter is greater than the diameter, in particular the second dimension of the sliding sleeve 5, so that an edge of the retaining element 12 projects beyond the sliding surface 16 and at one edge of the adjacent bearing element 8 is applied, so that the bearing element 8 is held between the holding member 12 and the spacer 17. The sliding sleeve 5 has three in the opening 14 projecting mounting portions 15, in each of which a mounting opening is provided. Each of the retaining element 12 has an opening 20, which is adapted in shape to the opening 14 of the sliding sleeve 5 and in the likewise mounting portions protrude with a mounting opening. Each of the holding elements 12 is in each case releasably securable to the sliding sleeve 5 with three fastening elements 13, which are each designed as screws. The fastening elements 13 pass through the fastening openings of the retaining element 12 and the sliding sleeve 5 and are predominantly arranged in a region enclosed by the sliding sleeve 5.

Above, with reference to an embodiment, a first pivot bearing has been explained, in which the bearing elements rest directly sliding on a sliding sleeve. It is understood that to improve the pivotability of the bearing elements to the sliding sleeve, the sliding properties improving measures can be provided, for example, the application of a lubricant. It is further understood that a bearing of the bearing elements can be done on the sliding sleeve by means of a ball or roller bearing, which is associated with higher costs. On the other hand, such a uniform force over the entire circumference of the sliding sleeve and the entire width of the sliding surface, as provided by the sliding sleeve, but without a resistance in the rotation is increased, achievable. It is also understood that dispenses with the provision of separate or separable bearing elements can be, in particular one-piece cross strut elements are preferably rotatably mounted directly on the sliding sleeve.

The features disclosed in the foregoing description, in the claims as well as in the figures may be essential to the invention in its various embodiments both individually and in any combination.

LIST OF REFERENCE NUMBERS

1

Cross strut assembly

2

pivot bearing

3

first cross strut element

4

second cross strut element

5

sliding sleeve

6

bearing tube

7

seat tube

8th

bearing element

9

first cross strut component

10

second cross strut component

11

seat

12

retaining element

13

fastener

14

opening

15

fastening area

16

sliding surface

17

spacer

18

opening

19

connecting section

20

opening

D

axis of rotation

a ₁ , a ₂ , a ₃ , a ₄

expansion

Claims (14)

Cross brace assembly for a wheelchair, in particular folding wheelchair, comprising a cross brace with at least one first cross brace element (3) and at least one second cross brace element (4), wherein the first cross brace element (3) and the second cross brace element (4) by means of a first axis of rotation (D) having the first rotary bearing (2) are mounted pivotably relative to each other,
characterized in that
the first pivot bearing (2) has at least one sliding sleeve (5) for receiving the first crossbar element (3) and / or the second crossbar element (4) rotatable relative to the sliding sleeve (5). Cross strut assembly according to claim 1, characterized in that the first cross strut element (3) and the second cross strut element (4) in each case, in particular about the first axis of rotation, are rotatably received on the sliding sleeve (5). Cross brace assembly according to claim 1 or 2, characterized in that at least one outer peripheral portion of the sliding sleeve (5) is designed as a sliding surface (16). Cross strut arrangement according to one of the preceding claims, characterized in that
the sliding sleeve (5) comprises at least two sliding surfaces (16), and that the sliding surfaces (16), in particular with respect to the first axis of rotation, are axially spaced from one another. Cross strut arrangement according to one of the preceding claims, characterized in that
the sliding sleeve (5), in particular in a receiving region for the first cross strut element (3) and / or the second cross strut element (4) and / or the sliding surface (16), a first extension (a ₁ ) in an axial direction of the first axis of rotation (D), in particular an outer circumference having a first cross-sectional diameter, and a second extension (a ₂ ) in a direction perpendicular to the first axis of rotation (D), in particular an outer circumference having a second cross-sectional diameter, that the first cross-strut element (3) and or the second cross strut element (4) at least in sections, in particular outside the region of the first pivot bearing (2) and / or as a tube, with a third extension (a ₃ ) parallel to the first axis of rotation (D), in particular a third cross-sectional diameter, and a fourth extension (a ₄ ) perpendicular to the first axis of rotation (D), in particular a fourth cross-sectional diameter is formed, and that the second extension (a ₂ ) is greater than the third extension (a3) and / or the fourth Extension (a ₄ ), and / or the first extent (a ₁ ) is substantially equal to or less than the third extent (a ₃ ). Cross strut arrangement according to one of the preceding claims, characterized by
at least one holding element (12) for, in particular with respect to the first axis of rotation (D), axial fixing of the first cross-strut element (3) and / or the second cross-strut element (4) on the sliding sleeve (5). Cross brace assembly according to claim 6, characterized in that at least two holding elements (12) are provided which limit the sliding sleeve (5) in, in particular with respect to the first axis of rotation (D), axial direction. Cross brace assembly according to claim 6 or 7, characterized in that the holding element (12) with at least one, preferably a plurality of fastening elements (13) on the sliding sleeve (5) can be fixed, wherein preferably the fastening element (13) at least partially in a is arranged by the sliding sleeve (5) enclosed area. Cross strut arrangement according to one of the preceding claims, characterized in that
the first cross strut element (3) and / or the second cross strut element (4) has or have at least one bearing element (8) which can be accommodated on the sliding sleeve (5). Cross-strut assembly according to claim 9, characterized in that the bearing element (8) has an opening (18) with a, to an outer diameter of the sliding sleeve (5), in particular the second extension adapted, inner diameter. Cross brace assembly according to claim 9 or 10, characterized in that the bearing element (8) has at least one inner sliding surface, which is designed to form a sliding pair with the sliding sleeve (5) and / or rests on the sliding sleeve as a press fit. Cross strut arrangement according to one of claims 9 to 11, characterized in that
the bearing element (8) for forming the first cross strut element (3) and / or the second cross strut element (4) with at least one cross strut member (9, 10) connectable, preferably releasably connectable, is. Cross strut arrangement according to one of the preceding claims, characterized in that
the first cross strut element (3) and / or the second cross strut element (4) is connectable or connected to at least one second pivot bearing (6) for rotatable mounting on at least one side frame of the wheelchair and / or at least one seat tube (7) of the wheelchair; are. Wheelchair, in particular folding wheelchair, with a cross brace arrangement (1) according to one of Claims 1 to 13.

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