DK2621443T3 - Seat device for example. wheelchair with dynamic seat pans - Google Patents

Description

Description

The invention relates to a seat arrangement for disabled persons, in particular wheelchair or pushchair, with a frame, which has two rails parallel to one another, and a seat surface arranged on the frame, which seat surface is fastened displaceably in the direction of the rails and pivotably on the frame.

Such a movable seat arrangement proceeds from European Patent EP 0 911 008 B1 of the applicant. The wheelchair described here or the seat arrangement described here serves in particular to accommodate patients suffering from spastic cramps. In the case of these patients, impulses are transmitted in an uncontrolled manner to the muscles, which impulses lead to cramp-like muscle tension which generally brings about stretching of the body. This means that the sitting person unintentionally activates his or her muscles such that the hip joints and knee joints are straightened. In order to avoid the patient falling out of the seat shell of the seat arrangement, the patient is generally fixed to the seat shell with fastening means, comprising, for example, a lap belt or lap band. In the case of conventional wheelchairs with a rigid seat or a locked, adjustable seat shell in which the patient is fixed, the muscle forces of the patient act in the event of a spastic attack against the rigid or locked seat shell which holds the joints of the patient in the angled position and fixes the patient in his or her seat position. This leads on one hand to it not being possible for muscle tension to lead to stretching of the body and the muscles and ligaments of the patients being exposed to high mechanical strain. The full muscle force is furthermore introduced into the fastening means and into the seat shell so that significant mechanical strain also arises here. The arrangement described in EP 0 911 008 B1 solves these problems by proposing that the seat surface and back rest are connected to one another in a freely pivotable manner, a tensioning device being provided which generates a tensioning force which holds the seat surface and the back rest in the bent seat position with respect to one another and that the foot rest is articulated freely pivotable on the seat surface, a tensioning device being provided which generates a tensioning force which holds the foot rest in the bent seat position with respect to the seat surface. In concrete terms, below the seat surface, a linear guide is fastened on the frame of the chassis. The seat surface is pivotably articulated on the displaceable component of the linear guide.

Other manufacturers have adopted this innovation as is apparent e.g. from publication EP 1 743 612 Bl. The mounting below the seat surface is brought about in that the end of the seat surface facing away from the back rest lies linearly displaceably on a rest so that this end is pivotable on the rest. JP2010-69283 A describes a multi-axis robot arm which bears a seat surface and is arranged on a movable frame, but is not displaceable with respect to the frame itself. Further supporting frames for seat surfaces are known from publications WO 90/00042, US 4 544 200, GB 2 272 633 A and US 2009/0218784 Al. Various linear guides and pivot connections for fastening a seat surface on a frame are described here.

The object of the present invention is to create a wheelchair or a similar seat arrangement for disabled persons in which the linear guide and pivotable articulation are formed in a simple structure with high stability and reliability.

This object is achieved according to the invention by the totality of the features of Claim 1. The seat arrangement comprises a fastening unit which fastens the seat surface displaceably and pivotably on at least one of the rails, wherein the fastening unit has at least one bearing through which one of the rails protrudes and which is displaceable in the longitudinal direction of the rail, wherein the fastening unit has a pivotable coupling element for fastening the seat surface, wherein the coupling element is located between the two rails.

In the case of previous wheelchairs, supporting elements for a linear guide, the displaceable component of which pivotably holds the seat surface, were arranged between the rails. This present invention now proposes using the rails of the frame themselves for fastening the seat surface. By using the stable and resilient rails of the frame for displaceable fastening of the seat surface, a separate linear guide with the required strength can be omitted. The construction is simpler and lower cost. By reducing the number of parts, maintenance outlay and susceptibility to faults are also reduced.

In practice, the fastening unit can be fastened displaceably on at least one rail and have a pivotable coupling element for fastening of the seat surface. The fastening unit is expediently displaceably fastened on both rails parallel to one another and the coupling element is located between the two rails. In this manner, optimum stability of the displacement guide of the fastening unit is achieved.

The displacement movement of the fastening unit is delimited by at least one stop and at least one bias spring pushes the fastening unit against the stop. The stop against which the bias spring acts is supposed to restrict the movement of the seat surface into the bent seat position so that the bias spring brings about the movement of the seat surface into this bent seat position. A second stop is also preferably provided which delimits the displacement of the seat surface into the extended position.

In practice, the pivoting movement of the coupling element can be delimited by at least one rotary stop and at least one return spring brings about a bearing against the rotary stop. This stop is also supposed to delimit the rotational movement in the direction of the angled seat position of the seat shell so that the return spring also moves the seat shell into the angled seat position. It is also expedient here to provide a second rotary stop which delimits the opening movement of the seat shell into the extended position.

In practice, the fastening unit can have two opposing ends, a displaceable bearing with a bearing bush being arranged at each end, through which bearing bush a rail protrudes. The fastening unit is consequently constructed as a cross strut with two bearing bushes at its ends which are displaceable in the longitudinal direction of the rails of the wheelchair frame. This structure is simple and low-cost and simultaneously extremely stable.

In practice, the bias spring can be a helical spring which presses against the axial bearing. The bias spring can surround the rail. For mounting of this linear bearing arrangement, the rail can be provided with an end piece, which is fastened detachably at the end of the rail. Prior to fastening of the end piece, the displaceable bearing and the bias spring can be pushed onto the rail. One end of the bias spring can bear against the end piece. The second end of the bias spring can bear against the displaceable bearing and push this against the stop which defines the angled seat position of the seat shell.

In practice, the fastening unit can have at least one pivot bearing which comprises two bearing parts which are rotatable with respect to one another. The bearing parts can, in the state fastened to one another, form a closed housing, wherein the two housing halves are rotatable in relation to one another. In practice, the bearing parts can consequently enclose a cavity. The return spring can be inserted in the cavity.

In practice, the one bearing part of the pivot bearing can be fastened on a displaceable bearing. If the fastening unit has two displaceable bearings at its ends, two pivot bearings of the described type adjoin the two bearings. The coupling element can be arranged centrally between the two pivot bearings. The coupling element is then consequently in the centre between the two longitudinal rails.

One embodiment of the invention is explained in greater detail below with reference to the enclosed drawings.

Fig. 1 shows an embodiment formed as a wheelchair of a seat arrangement according to the prior art in a side view in the unloaded starting position.

Fig. 2 shows the wheelchair of Fig. 1 with a seat shell and foot rest extended counter to the tensioning force of the tensioning devices.

Fig. 3 shows a wheelchair according to the invention in a three-dimensional view without padding on the seat shell.

Fig. 4 shows a side view of the frame of the wheelchair from Fig. 3 with an angled seat shell.

Fig. 5 shows a representation corresponding to Fig. 4 with an extended seat shell.

Fig. 6 shows a fastening unit of the wheelchair from Fig. 3 in a three-dimensional view.

Fig. 7 shows the fastening unit from Fig. 6 in an exploded representation.

Fig. 8 shows a three-dimensional view of a rail of the fastening unit.

Figs. 1 und 2 shows a seat arrangement in the form of a wheelchair according to the prior art. It comprises a chassis 1 with large rear wheels 2 and small front wheels 3 in each case on both sides of chassis 1. The upper part of chassis 1 is formed as a double frame 4 which is L-shaped in a side view. A plurality of cross struts (not represented) running transverse to the representation plane between the two L-shaped frame portions stabilise chassis 1. A seat shell 6 lies on L-shaped frame 4. It comprises a seat surface 7 and a back rest 8 which are connected to one another pivotably about a pivot axis 9. Pivot axis 9 between seat surface 7 and back rest 8 runs through the pivot point of the hip joint. A foot rest 10 is articulated pivotably about a pivot axis 11 at the front end of seat surface 7 in its two lateral wall portions. Foot rest 10 comprises here two struts which are parallel to one another and of which in each case only one is visible in Figs. 1 and 2 in a side view.

In order to offer the person to be accommodated a comfortable seat, padding supports are placed on seat surface 7 and back rest 8. These are not represented in the drawings for the sake of clarity. The seat arrangement is provided for accommodating a person suffering from spastic cramps which is fixed by fastening means in seat shell 6. A lap holder 13, which forms the fastening means, is plotted schematically with dashed lines in Fig. 1.

It is apparent in Fig. 2 that the seat arrangement can follow a stretching movement of the person accommodated in seat shell 6. The person can pivot foot rest 10 forwards by muscular strength and pivot back rest 8 backwards in relation to seat surface 7. Tensioning devices 14 and 15 are provided which pull the movable parts of the seat arrangement into the seat position represented in Fig. 1. First tensioning device 14 comprises a tension spring which on one hand is fastened on a receiving block 16 fixed on the L-shaped frame and on the other hand is connected to seat surface 7. The connection to seat surface 7 is carried out via a linear guide 17 below seat surface 7. The lower part of linear guide 17 is fastened on L-shaped frame 4. The front end of the upper part of linear guide 17 is connected pivotably to the underside of seat surface 7. Tension spring 14 is articulated at the rear end of the upper part of linear guide 17. Tension spring 14 thus pulls seat surface 7 into the rear position and thus entire seat shell 6 into the right-angled position represented in Fig. 1.

Tensioning device 15 also comprises a tension spring which is arranged between foot rest 10 and the upper part of linear guide 17. Said tension spring 15 pulls foot rest 10 into the rear, angled position as is represented in Fig. 1.

Fig. 3 shows a wheelchair according to the invention. The wheelchair comprises in turn a chassis 21 with large, rigidly mounted rear wheels 22 and two pivotably mounted front wheels 23 which enable steering of the wheelchair. Wheels 22, 23 are fastened on an L-shaped frame 24. L-shaped frame 24 serves to accommodate a seat shell 26.

Frame 24 with seat shell 26 is represented in a side view in two different positions in Figures 4 and 5. A handle 25, which serves to push the wheelchair, is arranged on two lateral vertical struts 33. Seat shell 26 comprises a seat surface 27 and a back rest 28. Back rest 28 is connected in an articulated manner to seat surface 27 by means of two pivot axes 29 which are formed e.g. by rivet or screw connections. A linear guide, which is represented in detail in Fig. 6, is arranged below seat surface 27.

Fig. 6 shows two horizontal rails 34, which are parallel to one another, of frame 24 which is L-shaped in the side view. A spreading strut 39 is arranged between the two horizontal rails 34 of frame 24 and keeps them at a distance. The front ends of rails 34 are a component of the linear guide for seat surface 27 of seat shell 26. It is apparent in Fig. 6 that an end piece 30 is screwed or fastened in another manner onto the front end of each of rails 34. End piece 50 has a larger diameter than rail 34. End piece 50 fixes on each rail pushed-on axial bearing 38 and a bias spring 41 which pushes bearing 38 away from end piece 50 to the rear. Each of rails 34 has a ring shoulder which has a larger diameter than rail 34 and forms a stop 40 (see Fig. 5). Bias spring 41 pushes displaceable bearing 38 against said stop 40. For forward displacement of bearing 38, end piece 50 forms the stop.

Each displaceable bearing 38 can have a bearing bush 42 made of PTFE or any other low-friction material. A bearing part 43 of a pivot bearing 37 is fastened on each displaceable bearing 38. Each pivot bearing comprises a second, bell-shaped bearing part 44 which is connected in a rotationally fixed manner to one end of a pivot axis 51 (see Fig. 7). Pivot axis 51 bears a coupling element 35 on which seat surface 27 can be fastened by means of a rapidly detachable fastening device.

It is apparent in Fig. 7 that the two bearing parts 43, 44 of the pivot bearing enclose an inner cavity. A rotary stop 45 of outer bearing part 43 protrudes into the inner cavity. A projection 46, which in two different rotational positions of inner bearing part 44 bears against in each case an end surface of rotary stop 45 of outer bearing part 43, is arranged on the inner bearing part. A leg spring forms a return spring 47 and interacts with the two bearing parts 43 and 44. Each outer bearing part 43 has a spring receptacle 48 into which a leg of leg spring 47 protrudes. Each inner bearing part 44 has a spring receptacle 49 for a second leg of leg spring 47. The two leg springs 47 rotate the two pivot bearings 37 into the starting position apparent in Fig. 4 or 6. Rotary stop 45 and projection 46 enable a pivoting of coupling element 35 forwards so that the front edge of seat surface 27 is lowered and the rear end of seat surface 27 is raised (cf. Fig. 5).

This construction integrates the displaceable guide and the pivot bearing for seat surface 27 in frame 24 of the wheelchair. Components can thus be saved and a low-cost and relatively lightweight design can be realised alongside very stable and reliable mounting of seat surface 27.

List of reference numbers 1 Chassis 2 Rear wheel 3 Front wheel 4 L-shaped frame 5 Horizontal strut 6 Seat shell 7 Seat surface 8 Back rest 9 Pivot axis 10 Footrest 11 Pivot axis 12 Foot placing board 13 Lap holder 14 Tensioning device, tension spring 15 Tensioning device, tension spring 16 Receiving block 17 Linear guide 21 Chassis 22 Rear wheel 23 Front wheel 24 L-shaped frame 25 Handle 26 Seat shell 27 Seat surface 28 Back rest 29 Pivot axis 33 Vertical strut 34 Horizontal rail 35 Coupling element 36 Fastening unit 37 Pivot bearing 38 Displaceable bearing 39 Spreading strut 40 Stop 41 Bias spring, helical spring 42 Bearing bush 43 Bearing part 44 Bearing part 45 Rotary stop 46 Projection 47 Return spring, leg spring 48 Spring receptacle 49 Spring receptacle 50 End piece 51 Pivot axis

Claims (5)

Seating device for physically handicapped persons, in particular a wheelchair or stroller, with a frame (24) provided with two parallel bars (34) and a seating surface (27) located on the frame (24) and capable of is displaced in the direction of the rods (34) and is pivotally secured to the frame (24), comprising a fastener (36) which secures the seating surface (27) slidably and pivotally to at least one of the rods (34), the fastener ( 36) is provided with a pivotable coupling element (35) for securing the seating surface (27), the coupling element (35) being between the two rods (34), characterized in that the fastening unit (36) is provided with at least one bearing. (38) through which one of the rods (34) protrudes, and which can be displaced longitudinally of the rod (34), that the sliding movement of the fastening unit (36) is limited by at least one stop (40) and that at least one bias spring (41) press the fastener (36) mo d the stop (40). Seating device according to claim 1, characterized in that the swinging movement of the coupling element (35) is limited by at least one pivot stop (45) and that at least one return spring (47) provides a connection to the pivot stop (45). Sitting device according to one of the preceding claims, characterized in that it comprises at least one of the following features: the fastening unit (36) has two opposite ends, with at each end a displaceable bed (38) with a bearing bush (42) through which a rod (34) projects; the bias spring (41) is a screw spring which presses against the sliding bearing (38); the bias spring (41) surrounds the rod (34); at the end of the rod (34) an end piece (50) is secured to which one end of the bias spring (41) is up, the other end of the bias spring (41) up to the displaceable bearing (38). Sitting device according to one of the preceding claims, characterized in that it comprises at least one of the following features: the fastening unit (36) is provided with at least one swivel bearing (37) consisting of two bearing parts (43, 44). ) that can be rotated relative to each other; the bearing members (43, 44) enclose a cavity into which the return spring (47) is inserted; the one bearing part (43) of the pivot bearing (37) is secured to the sliding bearing (38). Sitting device according to claim 4, characterized in that the coupling element (35) is positioned between the two longitudinal bars (34).