wheelchair

Abstract

Wheelchair (1) with - a basic framework (2) and - a body contact element (10) in the form of a backrest (14) which is arranged on the basic frame (2), characterized in that the backrest (14) is arranged on the basic frame (2) at least also by means of a pyramid adapter (16), wherein the pyramid adapter (16) has a spherical segment-shaped convex surface (36) with a centrally rising inverse pyramid (38) and can be inserted into an adapter receptacle (34) which has a spherical segment-shaped concave surface (44) and at least one adjusting screw (48) for each side of the pyramid (38) of the pyramid adapter (16).

Description

[0001] The invention relates to a wheelchair with a basic frame and at least one body contact element in the form of a backrest, which is arranged on the basic frame.

[0002] Wheelchairs have been known for many years as state-of-the-art technology. They feature a wide range of different body contact elements that come into contact with one or more parts of the user's body during use. Examples of body contact elements include the backrest, the seat, the footrests, the lower leg elements, and the armrests. In certain cases, headrests and other body contact elements may also be included.

[0003] Especially for people who are permanently dependent on a wheelchair, it is advantageous, and in many cases necessary, to individually adjust the position and / or orientation of the individual body contact elements to ensure optimal support. Such people often have spinal misalignments or other deformities of the skeletal system, which can be compensated for and / or individually supported by optimally adjusted body contact elements, thus providing the wheelchair user with the greatest possible comfort. This also prevents unwanted and potentially painful pressure points, which can severely limit the comfort of the wheelchair and also lead to wounds.

[0004] A whole series of wheelchairs are known from the state of the art in which, in particular, the backrest of the wheelchair can be adjusted to the individual circumstances of the wheelchair user.

[0005] US 2010 / 0276974 A1, for example, discloses a multi-part backrest whose individual parts can be tilted individually and independently of one another in different directions. US 8,517,469 B1, on the other hand, discloses a backrest for a wheelchair that is longitudinally displaceable in three directions and rotatable about an axis perpendicular to the support surface. Both designs utilize a multitude of different elements and components, making the construction of the wheelchair, and in particular its backrest, complicated and complex, and thus costly. Furthermore, individual parts can be lost, accidentally come loose, or accidentally misaligned.

[0006] WO 2017037751 A1 describes a headrest for a wheelchair that can be adjusted to various positions and orientations by means of a plurality of joints. EP 1 256 333 A2, on the other hand, discloses a seat for a wheelchair that has several body contact elements that can be moved relative to one another and locked in various positions. US Pat. No. 6,095,611 B1 describes a wheelchair with a modular backrest.

[0007] The adjustment of the backrest, in particular, is of utmost importance for the wheelchair user. Therefore, the current state of the art puts a great deal of effort into providing adjustability with as many degrees of freedom as possible. As already mentioned, this results in complicated solutions that require a relatively large amount of installation space. This shifts the backrest forward in the direction of travel, reducing the seat depth, i.e., the length of the seat surface in the direction of travel. However, this is uncomfortable for the wheelchair user and reduces comfort, so the complex mechanisms for setting and adjusting the position and / or orientation of the backrest must be relocated further back. The entire wheelchair becomes larger and heavier, and thus more difficult to maneuver.

[0008] The invention is based on the object of eliminating or at least mitigating these disadvantages of the prior art.

[0009] The invention solves the stated problem by a wheelchair according to the preamble of claim 1, which is characterized in that the backrest is arranged on the base frame at least also by means of a pyramid adapter, wherein the pyramid adapter has a spherical segment-shaped convex surface with a centrally rising inverse pyramid and can be inserted into an adapter receptacle which has a spherical segment-shaped concave surface and at least one adjusting screw for each side of the pyramid of the pyramid adapter.

[0010] Pyramid adapters have long been known in prosthetics and are used to adjust and position various prosthetic components relative to one another. The pyramid adapter itself can be arranged on the body contact element or on a component of the basic framework. It has a convex surface shaped like a spherical segment. An inverse pyramid, preferably four-sided, rises centrally. For the purposes of this invention, an inverse pyramid is understood to be a pyramid arranged such that its cross-sectional area increases starting from the convex spherical segment surface. The base of the pyramid therefore forms the part of the pyramid adapter furthest from the convex spherical surface.

[0011] The pyramid adapter is inserted into a correspondingly constructed adapter holder. This has a spherical segment-shaped concave surface. This is, for example, ring-shaped. The radius of curvature of the concave spherical segment surface of the adapter holder corresponds to the radius of curvature of the convex spherical segment surface of the pyramid adapter. For each side of the pyramid of the pyramid adapter, the adapter holder has at least one adjusting screw, which is, for example, designed as a grub screw. For assembly, the pyramid adapter is inserted into the adapter holder with the adjusting screws loosened. The two spherical segment-shaped surfaces of the pyramid adapter and the adapter holder are brought into contact. Since they have the same radius of curvature, the position and orientation of the pyramid adapter relative to the adapter holder can be freely adjusted within a certain angular range.Once the desired position and orientation is achieved, the adjusting screws are tightened until they rest against the sides of the pyramid, thus locking the pyramid adapter in the adapter holder.

[0012] The pyramid adapter has the advantage that the locking mechanism is not created solely by friction between the spherical segment-shaped surfaces, but primarily by the engagement of the adjusting screws on the side surfaces of the inverted pyramid of the pyramid adapter. This achieves a particularly secure, yet adjustable, positioning of the two components relative to each other, like a ball joint.

[0013] In prosthetics, this type of pyramid adapter is used to connect certain components of a prosthesis, for example an ankle joint and a lower leg tube, or a lower leg tube and a knee joint, or a knee joint and a prosthetic socket. The forces generated are particularly high with a leg prosthesis, as these prostheses are loaded with the wearer's full body weight. However, the respective forces are always introduced into the connection near the inverse pyramid of the pyramid adapter, so that the resulting torques, which act in the direction of twisting the adapter holder relative to the pyramid adapter, are relatively low. This is considerably different with a wheelchair according to the invention, in which the body contact element can be a backrest, for example. The backrest, for example, is essentially rectangular and has a side length of 40 to 60 cm, for example.If the pyramid adapter is located in the center of this rectangle, large torques can be exerted, particularly if the wheelchair user leans toward the outer areas of the backrest. This is especially true if the pyramid adapter is the only attachment method by which the body contact element is attached to the base frame. These large torques were previously considered too large for a single pyramid adapter, which is why the prosthetic adapter, known from prosthetics, has not been used in wheelchairs to date. To overcome this prejudice, however, the inventors surprisingly discovered that the pyramid adapter can provide sufficient stability, so that it can also be used in this application.

[0014] In a preferred embodiment, the wheelchair has at least one further body contact element in the form of a seat element, an armrest, a footrest, and / or a lower leg element. Particularly preferably, several body contact elements, particularly preferably all body contact elements of the wheelchair, are arranged on the base frame at least by means of a pyramid adapter. In this way, the entire wheelchair can preferably be individually adapted to the physical characteristics of the wheelchair user. Advantageously, the body contact element is arranged on a fastening device that is part of the base frame. The fastening device is mounted so as to be displaceable relative to the rest of the base frame in at least one, preferably two, and particularly preferably three directions.In a particularly simple embodiment, the fastening device is arranged as a carriage that is slidably mounted along one or more, preferably two, parallel rails. The rails themselves are slidably mounted, for example, along two bars, at the upper end of which, for example, grip elements can be located. In this way, the body contact element can be moved along the respective rails or bars and thus brought into the optimal position.

[0015] Particularly preferably, the at least two directions, preferably the three directions, are linearly independent and are preferably perpendicular to one another.

[0016] Due to the design of the body contact element arranged on the fastening device, the different degrees of freedom—i.e., the linear displacements in at least one, preferably two, particularly preferably three directions—and the tilting and angle adjustments enabled by the pyramid adapter can be adjusted independently of one another. In particular, for example, the inclination or tilt angle of the body contact element can first be adjusted by adjusting the pyramid adapter. Subsequently, the entire body contact element, for example, a backrest, can be displaced along one, two, or three directions without changing the orientation set by the pyramid adapter.In this way, it is easy for the orthopedic technician or even the patient to make adjustments to individual degrees of freedom without changing the settings for other degrees of freedom.

[0017] Preferably, the pyramid adapter is inserted into the adapter receptacle and secured with several, preferably four, adjusting screws. The adapter receptacle can be secured to a component of the base frame or the body contact element in various orientations. It has proven particularly preferred if the various orientations are rotated relative to one another about an axis of rotation, which is preferably the axis of symmetry of the adapter receptacle. In this way, the adjustability of the position and / or orientation of the body contact element can be achieved along a further degree of freedom. Thus, the body contact element can now be positioned in different positions, rotated about the axis of symmetry of the adapter receptacle.

[0018] It has proven advantageous if the body contact element is attached to the base frame by means of at least one additional support device. The additional support device is preferably adjustable and lockable. It can, for example, be a strut, one end of which can be moved along a rail and firmly connected to this rail, for example via a clamp or screw connection. If the position and / or orientation of the body contact element is adjusted, the additional support device is released so that, in particular, the pyramid adapter can be adjusted. Once the optimal position has been found, the additional support device can also be locked and exert its supporting effect.

[0019] Some embodiments of the present invention are explained in more detail with the help of the accompanying drawings. They show: Fig. 1 - the schematic perspective view of a wheelchair according to a first embodiment of the present invention, Fig. 2 - the rear view of the wheelchair Fig. 1, Fig. 3 - the perspective frontal view of the wheelchair from the Fig. 1 and Fig. 2, Fig. 4 - the side view of the wheelchair from the Fig. 1 to 3, Fig. 5 - the schematic view of a part of a wheelchair, Fig. 6 and Fig. 7 - schematic representations of different setting options, Fig. 8 - a pyramid adapter and an adapter holder in an exploded view, Fig. 9 and Fig. 10 - the illustration of further setting options, Fig. 11 and Fig. 12 - another embodiment of an adapter holder in an exploded and a perspective view, Fig. 13 - the schematic representation of a part of a wheelchair and Fig. 14 - the side view of the wheelchair from the Fig. 1 to 4.

[0020] Fig. Figure 1 shows a wheelchair 1 according to a first embodiment of the present invention. It has a basic frame 2 consisting of various rods and struts, on which two large rear wheels 4, each with a drive ring 6 for manually driving the wheelchair 1, as well as two small steering wheels 8 are arranged. The wheelchair 1 shown has two body contact elements 10, one of which forms a seat 12 and one a backrest 14. The backrest 14 is arranged via a pyramid adapter 16 on a carriage 18, which is guided along two struts 20 in Fig. 1 is arranged to be movable to the right and left. Clamps 22 are located at the ends of these struts 20, by means of which the struts 20 and thus also the slide 18, the pyramid adapter 16, and the backrest 14 are arranged on two bars 24 and are longitudinally movable thereon.

[0021] Fig. 2 shows the wheelchair 1 from Fig. 1 in a rear view. The carriage 18, on which the pyramid adapter 16 is located, can be moved right and left along the struts 20, and the struts 20 can be moved up and down along the beams 24 by means of the clamps 22. The pyramid adapter 16 itself allows tilting and pivoting, which is described in more detail below.

[0022] Fig. Figure 3 shows a perspective frontal view of the wheelchair 1 with the seat 12 and the backrest 14. The arrows 26 indicate the directions in which the backrest 14 is designed to be longitudinally displaceable. Note that these displacements along the arrows 26 are not enabled by the pyramid adapter 16, but by the slide 18, which is arranged on the struts 20 and, via the clamps 22, on the spars 24. Fig. 3 it can be seen that the wheelchair 1 has a third body contact element 10 in the form of a footrest 28.

[0023] Fig. 4 shows the wheelchair 1 in a side view with a patient 30. The backrest 14 is as in the Fig. 1 to 3 shown, whereby in Fig. 2 only one of the clamps 22 and a spar 24 is shown. The pyramid adapter 16, which in the illustration Fig. 4, now allows tilting and pivoting of the backrest 14, which is shown by the double arrows 32. If the upper area of ​​the backrest 14 is moved along the upper double arrow 32, for example, forwards, Fig. 4, i.e. to the right, the lower part of the backrest 14 is simultaneously shifted backwards along the lower double arrow 32, i.e. to the right in the figure.

[0024] Fig. Figure 5 shows a schematic top view of part of the wheelchair. It shows the backrest 14, which is mounted on the carriage 18 via the pyramid adapter 16. This is designed to slide along the strut 20, which is connected to the uprights 24 via the clamps 22. Fig. 6 shows the maximum displacement of the slide 18 along the struts 20. In the illustrated embodiment, displacement is possible until the backrest 14 abuts the respective clamps 22. In the upper part of the Fig. 6, the carriage 18 is along the strut 20 to the left and in the lower part of the Fig. 6 was moved to the right. The pyramid adapter 16 remained unchanged.

[0025] Fig. Figure 7 shows that the clamps 22 are also arranged to be movable along the struts 20. This allows the illustrated construction to be adjusted to a predetermined distance between the two struts 24. This makes it possible to use the same construction for different wheelchairs, reducing inventory and thus also lowering costs.

[0026] Fig. Figure 8 shows the pyramid adapter 16 and an adapter receptacle 34 in an exploded view. The pyramid adapter 16 has a convex spherical segment surface 36 from which an inverse pyramid 38 protrudes. The inverse pyramid 38 in the illustrated embodiment is four-sided and has four side surfaces 40, two of which are visible. The inverse pyramid 38 is inserted into a central recess 42 of the adapter receptacle 34. It is surrounded by a concave spherical segment surface 44, the radius of curvature of which corresponds to the radius of curvature of the convex spherical segment surface 36 of the pyramid adapter 16. Grub screws 48 can be inserted into four bores 46 and tightened until they rest against the side surfaces 14 of the inverse pyramid 38 of the pyramid adapter 16.

[0027] Fig. 9 shows a representation similar to the representations in the Fig. 5 to 7. In contrast, however, the pyramid adapter 16 and the adapter receptacle 34 are now shown. By tilting the adapter receptacle 34 relative to the pyramid adapter 16, whereby the convex spherical segment surface 36 of the pyramid adapter 16 slides on the concave spherical segment surface 44 of the adapter receptacle 34, the backrest 14 tilts relative to the strut 20 and thus relative to the basic frame 2, of which the struts 20 are a part. The dashed circle defines a section which is shown in Fig. 10 is shown enlarged. The slide 18 can be seen, which is designed to be longitudinally displaceable along the strut 20. The pyramid adapter 16 with the convex spherical segment surface 36 and the inverted pyramid 38 is also clearly visible. The same applies to the adapter holder 34 with its concave spherical segment surface 44. This rests against the convex spherical segment surface 36. The grub screws 48 are screwed into the bores 46 far enough that they rest against the side surfaces 40 of the inverted pyramid 38 and thus securely lock the adapter holder 34 relative to the pyramid adapter 16.

[0028] Fig. 11 shows another embodiment of an adapter receptacle 34. It also has an annular base body 50 with bores 46 into which the grub screws 48 are screwed. The inverse pyramid 38 of a pyramid adapter 16 can be inserted into the central bore 42. The base body 50 has a protruding annular flange 54 provided with teeth 52, the teeth 52 of which interact with corresponding teeth 56 on a retaining ring 58. In this way, the base body 50 can be locked in different positions relative to the retaining ring 58. The retaining ring 58 has four screw bores 60 through which screws can be passed in order to fasten the retaining ring and thus the adapter receptacle to the body contact element 10 or a part of the base frame 2. Due to the different positioning of the base body 50 relative to the retaining ring 58, the position of the grub screws 48 also shifts.Since these rest against the side surfaces 40 of the inverse pyramid 38 of the pyramid adapter 16 in the assembled state, the position of these side surfaces and thus also the orientation of the pyramid adapter 16 must also shift. Therefore, due to this design, the body contact element 10 can be positioned relative to the base frame 2 in different arrangements, which represent a rotation about the longitudinal axis of the base body 50.

[0029] Fig. 12 shows the adapter holder 34 from Fig. 11 in the assembled state. The base body 50 with the concave spherical segment surface 44 is mounted in the retaining ring 58 and locked by the teeth 52 and 56 (not shown). The base body 50 has a marking 62, which allows the settings to be reproduced once selected and the original zero position to be reached again.

[0030] Fig. 13 shows the already from the Fig. 5 to 7 known representation of the backrest 14, the strut 20 and the clamps 22, which are placed around the spars 24. The clamps 22 are arranged on the strut 20 via projections 64. This springs backwards, in Fig. 13 upwards, back, so that the installation space required for the pyramid adapter 16 and the adapter holder 34 does not or not significantly lead to a displacement of the backrest 14 forwards, in Fig. 13, i.e., downwards. Such a displacement results in a shortening of the seat surface 12 in the direction of travel and thus a reduction in the seat depth, which must be avoided.

[0031] Fig.Figure 14 shows a side view of wheelchair 1 without patient 30. By tilting the backrest 14 around the pyramid adapter 16 (not visible), the angle represented by the two curved arrows 66 is created between the backrest 14 and the seat 12, which in the illustrated embodiment is arranged parallel to an armrest 68. List of reference symbols 1 wheelchair 2 Basic framework 4 rear wheel 6 Drive ring 8 Steering wheel 10 Body contact element 12 Seat 14 Backrest 16 pyramid adapters 18 sleds 20 struts 22 clamp 24 Holm 26 Arrow 28 Footrest 30 patient 32 double arrow 34 adapter holder 36 convex spherical segment surface 38 inverse pyramid 40 side surface 42 central recess 44 concave spherical segment surface 46 Hole 48 grub screw 50 basic bodies 52 teeth 54 flange 56 tooth 58 retaining ring 60 screw holes 62 Marking 64 lead 66 curved arrow 68 Armrest

Claims

[1] Wheelchair (1) with - a basic framework (2) and - a body contact element (10) in the form of a backrest (14) arranged on the base frame (2), characterized by in that the backrest (14) is arranged on the basic frame (2) at least also by means of a pyramid adapter (16), wherein the pyramid adapter (16) has a spherical segment-shaped convex surface (36) with a centrally rising inverse pyramid (38) and can be inserted into an adapter receptacle (34) which has a spherical segment-shaped concave surface (44) and at least one adjusting screw (48) for each side of the pyramid (38) of the pyramid adapter (16). [2] Wheelchair (1) according to claim 1, characterized by that the wheelchair (1) has at least one further body contact element (10) in the form of a seat element (12), an armrest (68), a footrest (28) and / or a lower leg element. [3] Wheelchair (1) according to claim 1 or 2, characterized bythat the body contact element (10) is arranged on a fastening device which is part of the basic frame (2) and is mounted so as to be displaceable in at least one direction relative to the rest of the basic frame (2). [4] Wheelchair (1) according to claim 3, characterized by that the fastening device is mounted so as to be displaceable in at least two directions relative to the rest of the basic frame (2). [5] Wheelchair (1) according to claim 4, characterized by that at least two directions are linearly independent of each other. [6] Wheelchair (1) according to one of the preceding claims, characterized by in that the pyramid adapter (16) is inserted into an adapter receptacle (34) and is fastened with several, preferably four, adjusting screws (48), wherein the adapter receptacle (34) can be fastened to a component of the basic frame (2) or the body contact element (10) in different orientations. [7] Wheelchair (1) according to claim 6, characterized bythat the different orientations are rotated relative to each other about an axis of rotation, which is preferably an axis of symmetry of the adapter holder (34). [8] Wheelchair (1) according to one of the preceding claims, characterized by that the body contact element (10) is fastened to the base frame (2) by means of at least one additional support device. [9] Wheelchair according to claim 8, characterized by that the at least one additional support device is adjustable and lockable.

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