Abstract:
A seat backing formed by a closed hollow plastic jacket defining a chamber fillable with a fluid and a valve, provided in the jacket, serving for feeding the fluid to the chamber. The invention includes a bearing region for holding a seat; a sitting region for receiving a sitting person; and a transition region formed between the bearing and sitting regions. The sitting region includes an upper sitting region and a lower sitting region. The transition region includes upper and lower sections formed around the sitting region and the bearing region to be integrally interconnect the bearing region and the sitting region. The area of sitting and bearing regions increases when the seat backing is used.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a Continuation-in-Part of U.S. Ser. No. 10/0918,375, filed Aug. 16, 2004, which claims priority of DE 202004011087.3, filed Jul. 15, 2004, which applications are incorporated herein by reference in their entirety. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to a seat backing, Specifically, the present invention relates to a hollow seat backing having a particularly designed seat- and bearing region. A generic seat backing is already known from EP 705549 B1.  
       RELATED INFORMATION  
       [0003]     Various seat backings are known which are bolster-like and are therefore also referred to as seat bolsters. Such seat bolsters are either filled with elastic or resilient materials such as feathers, foam or the like, or their elastic stiffness is achieved by an enclosed fluid- or gas volume such as water or air. Also known are so-called seat bolsters which have a special wedge-shaped design and hence provide an inclined sitting face. From EP 1342434 A1, a wedge-shaped seat backing is already known. The existing elasticity of the seat backing was intended to allow the sitting person to sit in a dynamic, active and hence back muscles-strengthening manner. The special design of the seat bolster, which has a wedge-shaped cross section, pushes the pelvis to the front and supports an upright and hence correct sitting posture. Consequently, this design prevents back problems and corrects false posture.  
         [0004]     These known seat backings lead, however, to an ergonomically incorrect sitting posture and to incorrect active or dynamic sitting, as they comprise a direct, substantially vertical face having a low elastic concavity or curvature in the junction region between the sitting face and the bearing face. This vertical joining region of the seat backing does not allow a sufficient movement mobility of the sitting person when the pelvis moves laterally or forwards and backwards. These movements are also known for so-called sitz balls where the latent slight instability of the sitting position forces the body to make continuous compensating movements. Consequently, the back muscles are strengthened and positional failures or back problems and relevant diseases are prevented.  
       SUMMARY OF THE INVENTION  
       [0005]     Therefore, the present invention provides a seat backing which stands out for simple design and handling and which effects an ergonomically advantageous sitting position or posture of the person sitting thereon and also promotes dynamic sitting as is known to be advantageous and simultaneously allows tilting of the pelvis. It is further intended that the seat backing should provide a stable as well as largest possible sitting area for persons.  
         [0006]     According to an aspect of the invention, a seat backing having an inclined sitting face is provided. The seat backing comprises a closed hollow plastic jacket which defines a chamber fillable with a fluid.  
         [0007]     The fluid in the chamber is fed by means of a valve which is located on the plastic jacket and is integrated therein. The seat backing comprises a bearing region and a sitting region which is intended for receiving the sitting person. The bearing region and the sitting region are connected to a transition region provided therefor. The inclination of the sitting region in comparison with the bearing region according to the invention produces a top or upper and a bottom or lower sitting section of the sitting region. The inclination of the sitting region with respect to the bearing region according to the invention allows a slightly inclined sitting posture which fits in with the needs and habits of the sitting person which facilitates rocking of the spine of a person sitting on the sitting region proximate to the upper sitting region while substantially fixing the legs of the person sitting on the sitting region. The transition region according to the invention comprises an upper section and a lower section which are respectively formed around the sitting and bearing regions so that these sections mainly enclose the bearing face and the sitting face integrally and interconnect them. The faces of the upper and lower sections according to the present invention define in the upper and in the lower sitting region at least partially a sitting face which is increased when the seat backing is used, as the user deforms by his/her weight the transition region and uses the sitting region as a sitting face.  
         [0008]     The inclined face of the sitting region causes a greater elastic deformation of the transition region for a same weight of the user as compared with conventional seat backings or hollow bodies, namely particularly in the upper sitting region and the upper section of the transition region.  
         [0009]     It is preferred that the angle between the sitting region and the bearing region is about 4° to about 30°, particularly preferably about 4° to 14°. In this angle range, ergonomically particularly preferred elastic compensation movements of the body have been observed.  
         [0010]     It is preferred that the bearing region is defined substantially symmetrically to the sitting region. This is preferred in terms of the manufacturing technology and produces a homogeneously curved transition region.  
         [0011]     It is preferred that the area of the transition region of the upper section is substantially larger than the area of the transition region of the lower section. This serves the purpose of providing for application of a higher load in the upper sitting region.  
         [0012]     It is preferred that the transition regions formed around the sitting face and the bearing face has a cross section of which at least some sections are curved or bent. A preferred design has continuous transitions.  
         [0013]     It is preferred that the transition region formed around the sitting face and the bearing face has a cross section of which at least some sections are non-curved or have at least one straight section in the cross section. This allows a design in which plural straight sections are interconnected at an angle.  
         [0014]     It is preferred that the transition region forms a continuous marginal edge in the region of the lower sitting section to provide a low height dimension.  
         [0015]     It is preferred that the seat backing is at least partially made of thermoplastic plastic. This is preferred in terms of the manufacturing technology.  
         [0016]     It is preferred that the plastic jacket has protrusions made of the same material. It is preferred that the protrusions made of the same material result in improved elastic properties of the seat backing.  
         [0017]     Alternatively, it is preferred that the protrusions made of the same material produce a slip-resistant profile.  
         [0018]     It is preferred that the surface of the plastic jacket comprises a slip-resistant surface in predetermined regions of the sitting region or bearing region.  
         [0019]     It is preferred that the sitting region and the bearing region are substantially flat in the unloaded state. This prevents bulging and a deformation of the faces which is unfavorable to convenience. Moreover, a flat or substantially flat design provides an elastic deformation of the transition region.  
         [0020]     It is preferred that in the unloaded state the transition region, in the upper sitting region, substantially comprises a curved cross section or a cross section of which at least some sections are straight and in the lower sitting region, two partial regions meet in an acute angle and form an edge.  
         [0021]     It is preferred that the cross section of the seat backing is 25 cm to about 50 cm, particularly preferably 30 to 45 cm, and most preferably 35 to 40 cm.  
         [0022]     It is preferred that the height of the upper sitting region is 4 cm to about 15 cm.  
         [0023]     It is preferred that the height of the lower sitting region is 0 cm to about 4 cm.  
         [0024]     Other objects, advantages and features of the present invention will be apparent from the following exemplary description of preferred embodiments with reference to the accompanying drawings. Like reference numerals identify like parts throughout the drawings.  
         [0025]     A seat backing formed by a closed hollow plastic jacket defining a chamber fillable with a fluid and a valve provided in the jacket, serving for feeding the fluid to the chamber in accordance with the invention includes a bearing region intended for putting on a seat; a sitting region intended for receiving a sitting person which is inclined relative to the bearing region when placed on the seat; and a transition region formed between the bearing and the sitting region and interconnecting the regions; and wherein the sitting region comprises an upper sitting region which is proximate a spine of a person sitting on the sitting region and a lower sitting region which is proximate the legs of the person sitting on the sitting region; the transition region comprises upper and lower sections which are joined to define a periphery of the hollow plastic jacket and which extend inwardly from the periphery to join the sitting region and the bearing region and which sitting and bearing regions are separated only by the fluid with a distance of separation inside the jacket when filled with fluid between the upper and lower sections increasing from a minimum spacing at the lower sitting region toward the upper sitting region to a greater spacing whereby the person sitting on the sitting region may rock the spine forward and backward to vary the distance of separation between the upper and lower sections to a greater extent proximate the upper sitting region than proximate the lower sitting region; and the hollow plastic jacket is elastic so as in response to movement of the person sitting on the sitting region causes the periphery to increase to provide additional sitting region and bearing region area. An angle between the sitting region and the bearing region may be about 4° to about 30°. The angle may be about 4° to 14°. The bearing region may be defined substantially symmetrically to the sitting region of the transition region. The upper transition region may be a larger area than an area of the lower transition region which provides a greater flexibility between the sitting and bearing regions at upper transition areas than at the lower transition areas. The transition region may be a cross section with at least some part thereof is curved, bent or non-curved or has at least one straight section therein. The transition region may form a continuous marginal edge in a region of the lower section. The seat backing may at least partially be made of thermoplastic plastic. The plastic jacket may have protrusions made of a same material as the plastic jacket. The protrusions made of the same material may produce a slip-resistant profile. A surface of the plastic jacket may comprise a slip-resistant surface in regions of the sitting region or bearing region. The sitting region and the bearing region may be substantially flat in an unloaded state. In the unloaded state the transition region, the upper section may comprise a curved cross section or a cross section of which at least some sections are straight, and in the lower section, two regions may meet in an acute angle and form an edge. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a side view of the seat backing according to the invention.  
         [0027]      FIG. 2  is a top view of the seat backing according to the invention.  
         [0028]      FIG. 3  is another top view of another embodiment of the seat backing according to the invention, the circumference not being formed circularly or elliptically.  
         [0029]      FIG. 4  is another side view of another embodiment.  
         [0030]      FIG. 5  is another side view of another embodiment according to the invention.  
         [0031]      FIG. 6  is another side view of another embodiment according to the invention.  
         [0032]      FIG. 7  is another side view of another embodiment according to the invention.  
         [0033]      FIG. 8  is another side view of the invention.  
         [0034]      FIGS. 9 and 10  respectively illustrate a view of seat backing placed on a chair illustrating an unloaded state and a loaded state including the dynamic operation of the seat backing illustrated in phantom in  FIG. 9  in response to movement of the spine of a person sitting on the chair in  FIG. 10 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]      FIG. 1  shows the seat backing according to the invention in the side view. The seat backing has three main faces: a sitting face, a bearing face and a junction face which serves as a transition region. The seat backing provides two sitting sections which are defined according to the invention on the sitting face: an upper sitting region OS and a lower sitting region US. The dotted axes T-T′ and A-A′ illustrate the arrangement of the respective regions. With reference to  FIG. 1 , the transition region in the upper sitting region according to the invention is located to the left of the axis T-T′, whereas the transition region in the lower sitting region is located on the right-most side of  FIG. 1 . The transition region is divided into two partial regions: the sitting region STB and the bearing region ATB. These partial regions connect according to the invention the bearing face to the sitting face. The sitting partial region and the bearing partial region are concentrically formed around the respective sitting o r bearing faces to form a circular o r elliptical shape. Due to their special design, the faces of the partial regions contribute at least partially to the sitting region of the seat backing when the seat backing is used. The elastic properties of the plastic jacket and the fed-in fluid allow the transition region to bulge or increase “outwardly” to form an additional area for sitting or bearing as illustrated by phantom lines in  FIG. 9 . This effect produces dynamic sitting which is similar to well-known sitz balls without a risk of rolling away.  
         [0036]     Due to the inclined embodiment according to the invention, the required area of the sitting partial region and that of the bearing partial region are, in the acute-angled (lower) portion of the seat backing, smaller than in the region of the upper sitting section.  
         [0037]     When the sitting person uses the seat backing according to the invention, he/she can select in which sitting region he/she wants to sit. Alternating the upright position as illustrated in  FIG. 10  or the bearing places of the seat in the different sitting sections produce a so-called training effect whereby the back muscles are strengthened. In general, the embodiment according to the invention supports the horizontal and vertical movements of the pelvis and spine as illustrated in  FIG. 10  to allow dynamic or active sitting. The diameter of the seat backing D is 20 to 50 cm, preferably 30 to about 45 cm, and most preferably about 35 to 40 cm. The height H 1  of the upper sitting section is preferably 4 to about 15 cm, and particularly preferably about 5 to 7 cm. The height H 2  of the lower sitting section is preferably 0 to about 4 cm, and particularly preferably about 1 to 3 cm. The embodiment according to the invention produces an inclination angle W between the bearing face and the sitting face. This inclination angle is 40 to about 300, particularly preferably 4 to 14°. The arrow drawn by an extra-bold line is intended to symbolize the horizontal axis of the seat on which the seat backing is laid for use.  
         [0038]      FIG. 2  shows a top view of the sitting face of the seat backing according to the invention. In this embodiment according to the invention, the diameter D is the diameter in the circular top view. The dimension of the diameter is given in  FIG. 1 . The concentric circles form one possible arrangement of protrusions according to the invention which make the surface of the sitting face slip-resistant. Similar or equal protrusions may be preferably provided on the bearing region to achieve a similar effect with respect to the seat. The hatched concentric area shows that the transition region around the seat backing has a special design. In  FIG. 2 , the sitting partial region STB is shown, but the bearing partial region (not shown) is analogously formed around the seat backing on the bearing face. The reference symbol V symbolically shows one possible arrangement of the valve for feeding the fluid. The valve is preferably arranged in the upper sitting region, particularly preferably near the transition region.  
         [0039]      FIG. 3  is another top view of an embodiment according to the invention. I n this case, the sitting region or bearing region no longer has a circular or elliptical shape but is formed in a rounded manner on one side and is formed in a rectangular manner with rounded corners on the other side. The diameter of the semicircle which was used to form the seat backing is given the same dimension as in  FIG. 1 . The circularly shaped corners of the upper sitting section have radii R 2 . In this embodiment according to the invention, the radius R 2  is 2 to 12 cm, preferably 4 to 7 cm, particularly preferably about 6 cm.  
         [0040]      FIG. 4  is another side view of another seat backing according to the invention, some protrusions ANF made of the same material being shown symbolically. These protrusions may have different properties. On the sitting face and on the bearing face, they contribute to the slip resistance of the seat backing with respect to the sitting person or the seat. Similar protrusions on the sitting face or further in the transition region may also be provided for massage purposes. The arrangement of the protrusions in this figure are intended as a non-restricted example.  
         [0041]     The  FIGS. 5, 6  and  7  are an additional three possible embodiments of the seat backing in the side view. They are three possible embodiments of the connecting transition region and also show one possible non-symmetrical structure. In  FIG. 5 , a uniformly curved transition region is provided in an oval form. In  FIG. 6 , a transition region is shown which forms an angle of substantially 90° at the base and changes towards the top from a straight into a slightly rounded shape. Alternatively, a transition region having plural bosses or shoulders is shown in  FIG. 7 . The special shape of the transition region forming the shallow-out face of the sitting or bearing face allows to maintain the property of the increased sitting area. That is, the transition region contributes to the sitting area during use. The protrusions schematically represented in  FIG. 7  may have another shape as well.  
         [0042]     In  FIG. 8 , a transition region is represented schematically which shows a trapezoidal shape with plural adjacent straight lateral faces which form an obtuse angle and have rounded edges.  
         [0043]      FIGS. 9 and 10  respectively illustrate the seat backing of the invention positioned for intended use of a person sitting in the chair on which the seat backing is placed and the dynamic elastic deflection of seat backing when a person is sitting on the chair and rocks the spine forward and backward or side to side. The dotted line of the profile of  FIG. 9  illustrates the bulging of the transition region outwardly when a person is in a sitting position of  FIG. 10  which increases the area of the sitting region and bearing region. The dynamic bulging produces dynamic sitting of the well-known sitz ball which is facilitated by the elastic property of the hollow plastic jacket without a risk of rolling away. The dynamic movements illustrated by the solid line and dotted line profile of the person&#39;s spine facilitate a person sitting on the sitting region rocking the spine forward and backward or side to side to vary a distance of separation between the upper and lower sections to a greater extent proximate the upper sitting region than proximate the lower sitting region. The elastic property of the hollow plastic jacket causes the periphery of the seat backing to provide additional sitting region area and additional bearing region area and is flexible so as to duplicate the use of a sitz ball.  
         [0044]     While the invention has been described in terms of its preferred embodiments, it is intended that numerous modifications may be made thereto without departing from the spirit and scope of the invention. It is intended that all such  
         [0045]     Modifications fall with the scope of the appended claims.