Abstract
The invention relates to a seating device, such as for instance a chair or a wheelchair, with a seat and backrest extending between a first and a second side of the seating device for the purpose of supporting a seated person, which seating device can be folded into a collapsed position and a folded-out position. In the collapsed position the distance between the first and the second side is smaller than in the folded-out position, and which backrest includes a lumbar-thoracic support surface for supporting in the folded-out position the lumbar-thoracic transition area of a person situated in the seating device during use at a first angle relative to the horizontal plane.
Claims
1. A seating device, such as for instance a chair or a wheelchair, with a seat and backrest extending between a first and a second side of the seating device for the purpose of supporting a seated person, which seating device can be folded into a collapsed position and a folded-out position, wherein in the collapsed position the distance between the first and the second side is smaller than in the folded-out position, and which backrest comprises a lumbar-thoracic support surface for supporting in the folded-out position the lumbar-thoracic transition area of a person situated in the seating device during use at a first angle relative to the horizontal plane.
2. The seating device according to claim 1, wherein the backrest comprises on either side of the lumbar-thoracic support surface at least one fixation strap for lateral fixation of the upper body of a seated person, and wherein the at least one fixation straps are each attached with both outer ends to respectively the lumbar-thoracic support surface and respectively the first and the second side of the seating device.
3. The seating device according to claim 2, wherein the length between the outer ends of at least one fixation strap, preferably of all fixation straps, is adjustable.
4. The seating device according to claim 1, wherein the first angle lies in the range of 117-123.
5. The seating device according to claim 1, wherein the backrest comprises a support frame which extends between the first and the second side of the seating device, which support frame comprises a first and a second frame segment, which frame segments are mutually connected for pivoting about a central axis and wherein the first and the second frame segment are connected to respectively the first and the second side of the seating device for pivoting about respectively a first and a second side pivot axis, wherein the central pivot axis and the side pivot axes are parallel and which pivot axes form a second angle with the horizontal plane, which second angle is smaller than the first angle.
6. The seating device according to claim 5, wherein the lumbar-thoracic support surface is attached only structurally to the first frame segment.
7. The seating device according to claim 1, which seating device also comprises angle adjusting means, which angle adjusting means are configured to adjust the first angle.
8. The seating device according to claim 1, wherein the lumbar-thoracic support surface is a rectangle, preferably a rectangle with a width of about 8 cm and a height of about 12 cm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and other features of the invention are further elucidated with reference to the accompanying drawings.
[0029] The terms Fig., Figs., Figure, and Figures are used interchangeably in the specification to refer to the corresponding figures in the drawings.
[0030] FIG. 1 shows a perspective view of a first embodiment of a seating device according to the invention.
[0031] FIG. 2 shows a perspective view of the rear side of the first embodiment according to FIG. 1.
[0032] FIG. 3 shows a perspective view of the rear side of a second embodiment of a seating device according to the invention.
[0033] FIGS. 4a-c show a schematic representation of the lateral freedom of an upper body supported by support straps and FIG. 4c the lateral fixation of the upper body by the fixation straps according to the invention.
[0034] FIG. 5 shows a schematic definition of the angles in the sagittal plane.
DESCRIPTION OF THE INVENTION
[0035] FIG. 1 shows a perspective view of a foldable wheelchair 1 according to the invention. The seat of wheelchair 1 is not shown, making tubular frame 2 of wheelchair 1 visible. The lumbar-thoracic support surface 3 is arranged on the first frame part 4 of the support frame, which also has a second frame part 5. The first 4 and second 5 frame parts are connected to each other for pivoting about an imaginary central pivot axis 6. The other outer ends of frame parts 4, 5 are connected to frame 2 of seating device 1 for pivoting about imaginary side pivot axes 7. Fixation straps 8 are arranged on either side of the lumbar-thoracic support surface 3. The fixation straps 8 are arranged further toward the front edge of the seat (not shown) of wheelchair 1 relative to the lumbar-thoracic support surface 3. Fixation straps 8 hereby form a curve in top view, whereby the contour of the back of a person seated in wheelchair 1 can be followed. The lumbar-thoracic support surface can optionally be connected to first frame part 4 for pivoting about an imaginary horizontal axis, whereby the angle of the lumbar-thoracic support surface 3 relative to the seat or the horizontal surface can be varied further.
[0036] FIG. 2 shows a perspective view of the rear side of frame 2 of the wheelchair 1 according to FIG. 1. The first 4 and second 5 frame parts of the support frame are arranged on frame 2. The position of the support frame relative to frame 2 can be adjusted in simple manner by means of the angle adjusting means 9. The option of varying the relative height of support surface 3 relative to the support frame can be provided by means of for instance slotted holes arranged on the rear side of lumbar-thoracic support surface 3. Fastening holes are arranged in first frame part 4 for attaching the lumbar-thoracic support surface 3.
[0037] FIG. 3 shows a perspective view of the rear side of a second embodiment of a wheelchair 21 according to the invention. In this embodiment the lumbar-thoracic support surface 23 is attached relative to frame 22 by means of four straps 24 arranged on frame 22. In the folded-out position of wheelchair 21 the straps 24 are stretched tautly between the two sides of frame 22, whereby the lumbar-thoracic support surface 23 is fixed in height direction and lateral direction relative to frame 22. The relative position of the lumbar-thoracic support surface 23 relative to the seating device can optionally be varied by adjusting the length of straps 24, whereby the lengths of the different straps 24 must of course be adapted to each other so as to obtain the necessary fixation of the lumbar-thoracic support surface 23. In the collapsed position of wheelchair 21 the straps 24 are not tensioned and wheelchair 21 can be collapsed normally. As in the embodiment of FIGS. 1 and 2, the fixation straps 28 are arranged on the lumbar-thoracic support surface 23 and the sides of frame 22.
[0038] FIGS. 4a and 4b show a schematic cross-section in the transverse plane of the lateral freedom of an upper body 31 when supported by a support strap 32 attached to fixed lateral attachments 33 on either side of upper body 31. Support strap 32 follows the contour of upper body 31. FIGS. 4a and 4b show respectively a lateral translation 34 and 35 of upper body 31 relative to the centre line 36 of a lumbar-thoracic support surface 39. Upper body 31 is not laterally fixed by the support strap 32, whereby the upper body can move in the direction of the arrows 34-35, roughly parallel to the line between lateral attachments 33. FIG. 4c shows the lateral fixation by the fixation straps according to an embodiment according to the invention. Fixation straps 37 are connected at the outer ends to the lateral attachments 33 on one side and to a, or each to a, fixed central attachment 38 on the other. Because the freedom in the fixation straps 37 now exists roughly parallel to the line between a lateral attachment 33 and the fixed central attachment(s) 38, and these lines are not mutually in line, the upper body 31 supporting against both fixation straps 37 is fixed in lateral direction. A desired sitting support is hereby obtained, wherein the upper body is also fixed laterally. According to the invention, the lumbar-thoracic support surface 39 serves as fixed central attachment 38 because it is fixated at least in lateral direction relative to the seating device.
[0039] FIG. 5 shows a schematic view at right angles to the sagittal plane of the shown silhouette 41 of a seated person, in which the angles and are indicated in the sagittal plane. The seat surface 42 forms an angle with the horizontal plane 43. The contact surface 44 with the lumbar-thoracic support surface 45 forms an angle with seat surface 42. The first angle of the lumbar-thoracic support surface 45 relative to the horizontal plane 43 is therefore the sum of the angles and .
