Abstract
The invention relates to a seat for supporting a bottom of a seated user, which seat includes a first seat part for supporting a first part of the bottom of the user and a second seat part for supporting a second part of the bottom of the user. The first seat part is elastically deformable and has a first modulus of elasticity. The second seat part has a second modulus of elasticity which is at least 10 times greater than the first modulus of elasticity.
Claims
1. A seat for supporting a bottom of a seated user, which seat comprises a first seat part for supporting a first part of the bottom of the user and a second seat part for supporting a second part of the bottom of the user, wherein the first seat part is elastically deformable and has a first modulus of elasticity and wherein the second seat part has a second modulus of elasticity which is at least 10 times greater than the first modulus of elasticity.
2. The seat according to claim 1, wherein the first modulus of elasticity is smaller than or equal to 0.01 GPa.
3. The seat according to claim 1 , wherein the second modulus of elasticity is greater than or equal to 0.1 GPa and preferably lies in the range of 0.1-0.9 GPa.
4. The seat according to claim 1, wherein the first seat part lies centrally relative to the seat and the second seat part surrounds the first seat part.
5. The seat according to claim 1, wherein the first seat part comprises the projected position of at least one of the pubic area, the coccyx or one or both sit bones of the user.
6. The seat according to claim 1, wherein the second seat part comprises the projected position of at least a part of the thighbones of the user.
7. The seat according to claim 1, wherein the second seat part comprises flexible material and is preferably manufactured from flexible material.
8. The seat according to claim 7, wherein the second seat part is arranged between two frame parts and which seat comprises a tensioned position and a flexible position, wherein the second seat part is tensioned between the two frame parts in the tensioned position and is flexible in the flexible position.
9. The seat according to claim 1, wherein the first seat part comprises at least one elastic strap and preferably comprises at least one length-adjustable elastic strap.
10. The seat according to claim 1, wherein the first and/or the second seat part is covered with a soft foam layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The terms Fig., Figs., Figure, and Figures are used interchangeably in the specification to refer to the corresponding figures in the drawings.
[0033] FIG. 1 shows in top view a schematic view of an embodiment of a seat according to the invention.
[0034] FIG. 2 shows in top view a schematic view of an embodiment of a seat according to the invention.
[0035] FIG. 3 shows a perspective view of the seat of FIG. 2 in an unfolded wheelchair frame.
[0036] FIG. 4 shows a perspective view of the seat of FIG. 2 in a collapsed wheelchair frame.
[0037] FIG. 5 shows a schematic load pattern on a traditional seat.
[0038] FIG. 6 shows a schematic load pattern on a seat according to the invention.
[0039] FIG. 7 shows in rear view a section of the first seat part of a seat according to FIG. 2.
[0040] FIG. 8 shows in side view a section of a seat according to FIG. 2.
DESCRIPTION OF THE INVENTION
[0041] FIG. 1 shows a top view of a schematically shown seat 1 according to the invention. The seat 1 is used with the front side 2 at the position of the knees of the user during use. The backside of the user is then situated close to the rear side 3. Seat 1 comprises a first ventrally located seat part 4 which is surrounded by a second seat part 5. The first seat part 4 is elastically deformable and shapes itself to the adjoining supporting portions of the backside of the user during use.
[0042] FIG. 2 shows a top view of a schematic view of a second embodiment of a seat 11 according to the invention with a front side 12 and rear side 13. The first 14 and second seat part 15 are constructed from flexible material. The first seat part 14 is divided into strips 16 in the width direction. The middle part of each strip 16 is formed by an elastic segment 17, 18. The length of the elastic segment 17, 18 can be varied by applying a shorter segment 17 where less deformation is necessary and a longer segment 18 where more deformation is necessary. Depending on the weight of the user it is possible to opt for an elastic strap with a higher or lower modulus of elasticity. The degree of elasticity can also be varied by varying the length of the elastic segment 17, 18. For additional comfort a soft foam cushion with a thickness of at least 2 centimetres is placed over the bearing part.
[0043] FIG. 3 shows a perspective view of a bearing construction 19 of a seat 11 according to the embodiment shown in FIG. 2 and mounted in a wheelchair frame 20 in an unfolded and thereby tensioned state.
[0044] FIG. 4 shows a perspective view of the bearing construction 19 according to FIG. 3 a collapsed state in a wheelchair frame 20. This view clearly shows that the seat 11 is flexible.
[0045] FIG. 5 shows a load pattern 20 of a backside seated on a tautly tensioned net, which net is provided with about 2 centimetres of soft foam. The pressure variation varies from approximately 70 millimetres of mercury under the sit bones 21 to 40 millimetres under tail bone 22, and decreases to 0 millimetres of mercury toward the edges. It is clearly visible that it is precisely the critical parts 21, 22 that experience the highest pressure load.
[0046] FIG. 6 shows a load pattern 30 of a seated backside on a seat according to the invention, which seat is also provided with about 2 centimetres of soft foam. The pressure variation once again varies, yet now with a load on the upper legs of 70 millimetres of mercury 31, decreasing to about 15 millimetres of mercury 32 toward the sensitive sit bones and coccyx. The projections of the sensitive elements therefore lie in an area with a very low pressure load.
[0047] FIG. 7 shows in rear view a section of the first seat part 14 of a seat 11 according to FIG. 2. The elastic segment 18 of the strip 16 of the first seat part 14 is deformed and follows the contour formed by the sit bones 21 of the shown bone structure 24 of the pelvis.
[0048] FIG. 8 shows in side view a section of a seat 11 according to FIG. 2. The shown bone structure 24 of the pelvis and upper leg 25 are supported by respectively the first seat part 14 which has shaped itself to the contour and the second, posture-imparting seat part 15. In combination with a backrest (not shown) a sustainable seating is obtained with a seat 11 placed at the correct angle , wherein the risk of decubitus symptoms is reduced in effective manner.
