Abstract:
The invention relates to a sitting support, comprising a base and at least one upper part moveable relative to the base, wherein, by the or each upper part, a sitting surface is determined on which, during use, at least one ischium of a user rests, wherein, for said base and said at least one upper part, drive means are provided for reciprocally driving the respective upper part relative to the base part.

Description:
RELATED APPLICATIONS  
       [0001]     This application is a continuation of PCT application no. PCT/NL2005/000017, designating the United States and filed Jan. 13, 2005; which claims the benefit of the filing date of Dutch application no. NL 1025228, filed Jan. 13, 2004; both of which are hereby incorporated herein by reference in their entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to a sitting support. The invention particularly relates to a sitting support with which, during sitting, complaints of a user can be prevented and/or remedied.  
       BACKGROUND OF THE INVENTION  
       [0003]     It is known that sitting on a chair can lead to various complaints in a user, for instance lower back complaints. In order to at least partly obviate this problem, special, ergonomically adapted chairs are used that are, nevertheless, particularly expensive and are usually only suitable for one user. Particularly also for people with a physical disability, individually adapted sitting supports are used that are expensive and regularly need to be adjusted.  
       SUMMARY  
       [0004]     It is an object of the invention to provide a sitting support that actively contributes to the health and the wellbeing of the user during use.  
         [0005]     A further object of the invention is to provide a sitting support that is easy to use and maintain and is particularly safe for the user.  
         [0006]     A further object of the invention is to provide a sitting support that is universally applicable and can simply be used in different chairs, sofas and the like.  
         [0007]     At least a number of these and other objects are achieved with a sitting support according to the invention.  
         [0008]     In a sitting support according to the invention, on a base, at least one upper part is borne, on which the user can sit during use. The or each upper part can move relative to the base, in particular reciprocally driven with the aid of drive means. As a result, in the user, a movement of the pelvis relative to the spinal column is induced that has a stimulating effect on the user. Complaints such as lower backache, but also headache, stiffness, shoulder complaints, decubiti and other complaints can be prevented or remedied thereby, while, moreover, the blood perfusion to particularly the extremities is stimulated.  
         [0009]     A sitting support according to the invention has the advantage that it can simply be taken along and can be placed on different chairs, which are at least understood to mean any piece of furniture, surface or other element suitable for seating that can carry a sitting person. This allows a user to use this sitting support anywhere. Here, what is particularly advantageous is a sitting support according to the invention that is provided with an electric drive, fed by batteries, an accumulator or similar power supply independent of the electricity grid. A further advantage of a sitting support according to the invention is that it is universally applicable, although, of course, an ergonomically shaped and/or individual top surface can be used.  
         [0010]     Herein, a reciprocal movement is understood as at least comprising one rotating, at least pivotal movement and/or a translating movement, where a path is alternately traveled in opposite directions.  
         [0011]     The reciprocal movement preferably has a frequency of less than 5 Hz, more in particular less then 2 Hz. It has been found that a low frequency is preferred, for instance less than 0.12 Hz, in particular 0.08 Hz or less.  
         [0012]     In a first advantageous embodiment, one upper part is provided, pivotally about a central axle. Here, the user sits on the top surface and his or her pelvis is rotated. Here, it is preferred that the user rests his or her back against a back rest. Here, the pivotal angle is preferably settable and relatively small, for instance a few degrees with respect to the axial line.  
         [0013]     In a second embodiment, the sitting surface is formed by two top surfaces driven in opposite directions, going back and forth so that the desired reciprocal movement is obtained. The movements of the top surfaces are preferably linear. Here, the stroke of each top surface relative to a middle position is relatively small, for instance a few centimeters.  
         [0014]     During use, the user will rest on the or each top surface with his or her ischia. As a result of the reciprocal movement, a continuously varying sitting load can be obtained, in particular around the ischia.  
         [0015]     In a particularly simple embodiment, the sitting support substantially consists of a dish-shaped base on which an upper part rotatable about a central axle is borne by a bearing. Particularly suitable for this are, for instance, cylindrical bearings or barrel thrust bearings between the base and the upper part. The upper part preferably comprises a plate with a sitting cushion thereon. The plate and the base may be provided with a suitable profiling for the bearing. Here, drive means are provided between the base and the upper part, preferably in a thus formed substantially closed space. Drive means having a simple design may for instance comprise an eccentric, driven by an electric motor, for obtaining reciprocal movements. On the bottom side, the base is preferably provided with friction-increasing means such as studs, rubber or different plastic feet or the like, for a stable placement on a seat. Operating means may be provided on or near the top side for switching on and off and optionally setting the pivotal angle, the movement frequency and the like.  
         [0016]     In the alternative embodiment described with two upper parts moving relative to each other, a similar structure with base and upper parts can be chosen, where an eccentric can be used for the drive. Here, alternatively, a rotating disc or the like can also be used for the movement of the upper parts.  
         [0017]     The invention further relates to a method for moving a sitting person. According to the invention, such a method is characterized by the measures according to claim  12 .  
         [0018]     Such a method has the advantage that a user can apply it to any chair, with chair needing to be given a broad interpretation. With this method, the sitting comfort of the user is enhanced and complaints such as back and neck complaints and headache are prevented or reduced, while, moreover, for instance the blood circulation can be stimulated and a positive effect against RSI can be obtained. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]     In clarification of the invention, exemplary embodiments of a sitting support, assembly and method according to the invention will be further described with reference to the drawing. In the drawings:  
         [0020]      FIG. 1  shows, in disassembled condition, a sitting support according to the invention, in a first embodiment;  
         [0021]      FIG. 2  shows, in top plan view, an upper dish part of a sitting support according to  FIG. 1 ;  
         [0022]      FIG. 3  shows, in perspective view, a drive device with accumulator for a sitting support according to the invention;  
         [0023]      FIG. 4  shows, in perspective view and top plan view, a bearing part for a sitting support according to  FIG. 1 ;  
         [0024]      FIG. 5  shows, in cross-sectional view, a part of an edge of a sitting support according to  FIG. 1 , in which the bearing is shown;  
         [0025]      FIG. 6  shows, in top plan view, a sitting support according to  FIG. 1 ;  
         [0026]     FIGS.  7 A-C show three partial cross-sections according to lines A-A, B-B and C-C in  FIG. 6 ;  
         [0027]      FIG. 8  schematically shows an eccentric of the drive device in an opening in the base;  
         [0028]      FIG. 9  schematically shows, in top plan view, an alternative embodiment of a sitting support according to the invention;  
         [0029]      FIG. 10  schematically shows a drive device for a sitting support according to  FIG. 9 ; and  
         [0030]      FIG. 11  shows, in side elevational view, a sitting support according to the invention on the seat of a chair with a user. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0031]     In this description, identical or corresponding parts have identical or corresponding reference numerals. The exemplary embodiments shown are merely shown by way of illustration and should not be construed as being limitative in any manner.  
         [0032]      FIG. 1  shows, in disassembled condition, a sitting support  1  according to the invention. In the drawing, shown from bottom to top are a base  2  in the form of a lower dish  3 , manufactured, for instance, from plastic, and an upper part  4 . This upper part  4  is built up from an upper dish  5 , for instance from plastic, with a stiffening plate  6  thereon, for instance from metal. On the stiffening plate  6 , a sitting foam  7  is borne, covered by an upholstery  8 . On the upper dish  5 , a drive unit  9  is borne, and a control unit  10 . An accumulator  11  is provided, preferably in the lower dish  3  which is connected, via a cable  12 , with the drive unit  9  and/or the operating unit  10  and can be fed via the mains. Between the upper dish  5  and the lower dish  3 , bearings  13  are included. An axle  14  is formed by a connecting bolt  15  and a nut  16  with which the upper dish  5  can be attached to the lower dish  3  so as to be rotatable, at least pivotable about the axle  14 .  
         [0033]     In  FIG. 5 , in cross-sectional side elevational view, a part of a sitting support  1  according to  FIG. 1  is shown. Here, the different parts are clearly shown in assembled condition. On the bottom side of the lower dish  3 , a number of friction-enhancing means  17  are provided in the form of rubber legs  18 . Therewith, the sitting support  1  can be placed on the seat  19  of a chair  20 , as schematically shown in  FIG. 11 . It is clear, that in the embodiment shown, the bearings  13  comprise barrel thrust bearings  21  and pivot bearings  22  for bearing the upper part  4  on the base  2  so that the upper part  4  can flexibly pivot about the axle  14 .  
         [0034]     The upholstery  8  has been pulled over the foam  7  and fixed with a drag cord  23  below the edge of the stiffening plate  6 . Subsequently, the stiffening plate  6  has been fixed on the upper dish  5 , for instance by clamping pins  24  or in a different suitable manner  
         [0035]      FIG. 3  shows the drive unit  9  with the control unit  10  and the accumulator  11 . The drive unit  9  comprises a motor  25  and a drive wheel  26 , placed eccentrically on an axle  27 . Suitable transmission has been provided between the motor  25  and the axle  27 , for instance a sprocket transmission, worm wheel or the like. In  FIG. 8 , it is schematically shown how the drive wheel  26  has been placed in a recess  28  in the lower plate  3 . The drive unit  9  itself is attached to the upper dish  5 , with the drive wheel  26  reaching through an opening  29 . Consequently, upon rotation of the drive wheel  26  about the axle  27 , the upper dish  3  and hence the upper part  4  will be pivoted through a small angle α relative to a middle position, symbolically indicated with the line M-M in  FIG. 6 . Preferably, the angle α is small, for instance less than 20°, more in particular less than 10°. In the embodiment shown, this angle is for instance smaller than 5°, in particular approximately 2.5°. Naturally, this angle depends on inter alia the eccentricity of the drive wheel and its size and its position relative to the axle  14 . Optionally, its design can be settable, for instance by settability of the eccentricity and/or the possibility of moving the drive unit  9  relative to the axle  14 .  
         [0036]      FIG. 2  shows, in top plan view, the arrangement of the drive unit  9  and control unit  10 , and of the accumulator  11 . Furthermore, three paths  30  for the barrel thrust bearings  21  can be seen here. These paths  30  each include an angle of for instance approximately 100°, so that three sets  31  of barrel thrust bearings  21 , as shown in more detail in  FIG. 4 , can be placed therein and can only travel a limited path.  
         [0037]     The control unit  10  is designed for switching the motor  25  on and off and, optionally, for setting the frequency for the reciprocal movement by setting the speed of rotation of the drive wheel  26 , at least of the motor  25  or of the transmission ratio. The reciprocal movement P is shown in  FIG. 6  by arrow P and is the pivotal movement back and forth through the angle a.  
         [0038]      FIG. 4  shows a set  31  of barrel thrust bearings  21 . In the set  30 , a strip  32  is included, bent through a bending radius matching those of the paths  30 . In the form shown, each strip comprises eight radially extending pins  33  on which, each time, one barrel thrust bearing is placed. The pins are split and provided with a widening  34  at their ends. The bearings  21  can simply be pressed over the pins such that they are confined between the strip  32  and the widening  34 . Optionally, the bearings  21  can be confined between two strips bent complementary, as schematically indicated at the top of  FIG. 4 , in broken lines.  
         [0039]     As appears from  FIG. 5 , the paths  30  are provided in the lower dish  3  and upper dish  5  and each formed such that the barrel thrust bearings  21  are confined therein secured against lateral displacement.  
         [0040]     In FIGS.  7 A-C, three parts of cross-sections are shown, from which the profilings of the edges of lower dish  3  and upper dish  5  are given. In  FIG. 7A , a handle  60  is visible for taking up and taking along the sitting support in a simple manner. It clearly appears from  FIG. 7  that the space between the lower dish  3  and the upper dish  5  is substantially closed off.  FIG. 1  shows that the accumulator can be placed from the bottom side into a recess  36  in the base  2 , which can be closed off by a cover plate  37 .  FIG. 5  shows a further cover plate  38  below the bolt  15  so that the bottom side is relatively flat. The drive unit  9  and control unit  10  have been arranged near a longitudinal edge of the sitting support  1 , as shown in  FIG. 6 , while the sitting cushion (foam  7  and upholstery  8 ) are formed there around. Preferably, these are situated at the front so that they are easily reachable.  
         [0041]      FIGS. 9 and 10  show an alternative embodiment, in which two upper parts  4 A,  4 B are borne on a base  2 . In  FIG. 10 , the upper parts  4 A,  4 B have been taken away in order to make the drive unit  9  visible. In this embodiment, the upper parts  4 A,  4 B move substantially linearly in the directions P, while each time, it holds that, if the left upper part  4 A moves forwards, the right upper part  4 B moves backwards and vice versa, so that reciprocal movements are obtained. For this purpose, a motor  26  is provided, driving a disc  40  about an axle  41 . On this disc, eccentrically, a rod  42  is pivotally connected by a first end  43 . A pivot arm  44  is placed on a central axle  45  such that the pivot arm can pivot about the axle  45 , approximately in the plane of the drawing. The two ends  46 A,  46 B of the pivot arm are attached against the bottom side of the left and right upper part  4 A,  4 B, respectively. The second end  47  of the rod  42  is attached to the pivot arm  44 , at a distance from the axle  45 . Hence, through rotation of the disc  40 , the pivot arm  44  will start a reciprocal pivotal movement through an angle α, so that the movement back and forth of the two upper parts  4 A,  4 B is obtained over a distance D. The upper parts  4  are borne on the base  2  by suitable means, for instance slide bearings or roller bearings to which end, on the bottom of the base  2 , suitable rails  48  may have been provided. In this embodiment as well, the stroke D can be set, if desired. Preferably, the stroke D is relatively small, for instance less than 15 cm, more in particular less than 10 cm. Preferably, the stroke D is less than 5 cm, for instance between approximately 0.5 and 2 cm.  
         [0042]     Preferably, a sitting support is relatively light and small in size so that it can easily be taken along, for instance in a case. The height H is preferably less than 20 cm, in particular less than 10 cm, more in particular between 0.5 and 8 cm, so that, within a normal range of adjustment of a chair and, optionally, arm rests and/or back rest thereof, an ergonomically correct sitting height can be obtained with the sitting support on the seat. Preferably, the length L and width B are smaller than 60 cm, more in particular smaller than 50 cm and preferably between 20 and 45 cm, so that it fits on a seat. However, these sizes are not limitative in any manner.  
         [0043]     As shown in  FIG. 11 , during use, a user  50  sits on the sitting support  1 , while his or her ischia rest on the upper part  4 , as indicated in  FIGS. 6 and 9  by means of circles  52 . The sitting support rests on the seat  19  of the chair  20  or any other suitable support, for instance a wheelchair, sofa, surface or the like. When the sitting support  1  is switched on, the desired reciprocal movement will be obtained, so that the pelvis of the user will be pivoted back and forth, approximately through the angle α. Preferably, the user then sits with his or her back against a rest  53  of the chair  20 , so that the pivotal movement of the pelvis will occur relative to the lower back, at least the lumbar part thereof. Thus, a method is used which improves the sitting comfort and which is ergonomically justified.  
         [0044]     It has appeared that this is particularly stimulating for the user, that complaints can be prevented and/or counteracted such as, for instance, lower back complaints but also circulatory problems, upper back complaints, RSI complaints, headaches and similar complaints directly or indirectly linked to the locomotor apparatus of the user. It has further appeared that a low frequency of movement is then advantageous, for instance less than 0.12 Hz, for instance between 0.04 and 0.08 Hz, although, naturally, other frequencies can also be used.  
         [0045]     In the sitting support  1 , a contact switch  54  can be provided with which the drive unit  9  is switched on if a user sits down on it and is switched off when the weight is removed.  
         [0046]     Naturally, the invention is by no means limited to the embodiments shown and described. Many variations thereon are possible within the framework of the invention as outlined by the claims. For instance, a sitting support according to the invention may have a different structure, for instance with the drive unit in the space between lower and upper dish, its form can be chosen to be different, as can the construction, a different sitting cushion can be used, for instance a separate sitting cushion that is borne on the upper dish and is easily exchangeable and/or cleanable and can be attached with, for instance Velcro®. Also, the top surfaces can be formed differently, depending on, for instance, the wishes of the user. The sitting support can also be driven in a different manner, for instance by means of a linkage mechanism or similar mechanisms known to a skilled person. The drive can also be positioned elsewhere, for instance below, next to or above the base. These and many similar variations and alternatives are understood to fall within the framework of the invention as outlined by the claims.