Patent Publication Number: US-2004055091-A1

Title: Ergonomic seat

Description:
1. FIELD OF THE INVENTION  
       [0001] The present invention relates generally to seats. More particularly, the present invention relates to an ergonomic seat providing improved comfort and pressure relief.  
       2. BACKGROUND OF THE INVENTION  
       [0002] Almost anyone who has ever attended a sporting event is well aware of the discomfort associated with stadium bleachers. In an effort to alleviate the discomfort, many attendees of sporting events carry various types of so called “bleacher seats” with them to the event. These bleacher seats are available in a variety of styles and configurations, including simple foam or air cell seat pads which are loosely positioned between the person&#39;s rear and the bleacher, to folding seats without legs that are attached or anchored to the bleacher to provide at least some amount of back support and rear cushioning. While such bleacher seats provide some level of improvement to the overall comfort of the seat occupant, they fail to address a major causal factor for the discomfort.  
       [0003] What is needed, therefore, is an ergonomically designed seat that reduces bodily stress or pressure and improves physical comfort without the need for back support structure.  
       SUMMARY OF THE INVENTION  
       [0004] The present invention achieves its objectives by providing an ergonomic seat that promotes good seating posture for an occupant of the seat. The seat includes a rear portion for supporting at least a portion of the occupant&#39;s rear. A front portion in opposed relation to the rear portion supports at least a portion of the occupant&#39;s thighs. The seat also includes opposed first and second side portions. A seating surface extending between the front, rear, and side portions is angled downwardly from the rear to the front to enable an occupant of the seat to go from a standing to a sitting position with little or no additional pressure on the lumbar discs of the occupant.  
       [0005] In a preferred embodiment, the angle between the rear and front portions is between about 10 degrees to about 30 degrees. A particularly preferred angle is about 15 degrees.  
       [0006] The seating surface may be contoured to more evenly distribute weight of the occupant across those portions of the occupant&#39;s rear and thighs that are in contact with the seating surface.  
       [0007] In one embodiment, the seat is configured for use as a stadium seat and includes one or more fasteners for removably attaching the seat to a bleacher or other similar support structure.  
       [0008] The seating surface is preferably fabricated from a substantially rigid material, and may, if desired, include a thin outer layer of resilient material to further promote comfort. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0009] Preferred embodiments of the invention will now be described in further detail. Other features, aspects, and advantages of the present invention will become better understood with regard to the following detailed description, appended claims, and accompanying drawings (which are not to scale) where:  
     [0010]FIG. 1 is a perspective view of an ergonomic seat according to the invention;  
     [0011]FIG. 2 is a top plan view of the ergonomic seat of FIG. 1;  
     [0012]FIG. 3A is a sectional view of the ergonomic seat of FIG. 2 taken along section line  3 A- 3 A;  
     [0013]FIG. 3B is a sectional view of the ergonomic seat of FIG. 2 taken along section line  3 B- 3 B;  
     [0014]FIG. 3C is a sectional view of the ergonomic seat of FIG. 2 taken along section line  3 C- 3 C;  
     [0015]FIG. 3D is a sectional view of the ergonomic seat of FIG. 2 taken along section line  3 D- 3 D;  
     [0016]FIG. 4 is side view of the ergonomic seat of FIG. 1; and  
     [0017]FIG. 5 is a side view of the ergonomic seat of FIG. 1 in use on a stadium bleacher. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)  
     [0018] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, wherein like reference characters designate like or similar parts throughout. The terminology used herein is intended to be interpreted in its broadest reasonable manner, even though it is being utilized in conjunction with a detailed description of certain specific preferred embodiments of the present invention. This is further emphasized below with respect to some particular terms used herein. Any terminology intended to be interpreted by the reader in any restricted manner will be overtly and specifically defined as such in this specification.  
     [0019]FIGS. 1 and 2 illustrate an ergonomic seat  10  for promoting good seating posture. The seat  10  includes a rear portion  12  for supporting at least a portion of the occupant&#39;s rear, and a front portion  14  for supporting at least a portion of the occupant&#39;s thighs. The seat  10  further includes a left side portion  16  in opposed relation to a right side portion  18 . The occupant sits on an upper seating surface  20  which is in opposed relation to a seat bottom  22 . Seating surface  20  is preferably fabricated from a substantially rigid material and contoured to more evenly distribute weight of the occupant across those portions of the occupant&#39;s rear and thighs that are in contact with the seating surface  20 . In a preferred embodiment, the seating surface  20  is fabricated from a substantially rigid material (such as plastic or closed cell foam) to form a substantially rigid seating structure. The seating surface  20  may be fabricated as part of a plastic shell encapsulating hardened foam or other material. Alternatively, the entire seat  10  may be of single piece construction and fabricated from a suitable substantially rigid material.  
     [0020] In the embodiment shown in FIGS. 1 and 2, the seat  10  is configured for use as a so-called “stadium seat” where the seat  10  is used to augment an existing substantially horizontal seating surface, such as a stadium bleacher or other bench-type seat. For the seat  10  of FIG. 1, the seat bottom  22  is preferably substantially flat so as to rest flush against the bleacher. If desired, the seat  10  may be secured to the bleacher with the use of one or more fasteners. For example, one or more woven straps  24 ,  24 ′ with ends that are joined together by male connectors  26 ,  26 ′ and female connectors  28 ,  28 ′ function as suitable fasteners for securing the seat  10  to a bleacher.  
     [0021] As stated above, the seating surface  20  is preferably contoured for more even weight distribution, and this is preferably accomplished by shaping the seating surface  20  to more closely approximate the contour of that portion of the occupant&#39;s thighs and buttocks that are in contact with the seating surface  20 . FIGS.  3 A-D illustrate a preferred contouring of the seating surface  20 . FIG. 3A shows a cross-section of the seat  10  taken along section line  3 A- 3 A of FIG. 2. As can be seen in FIG. 3A, the upper seating surface  20  is slightly below the rear seat portion  12  at section line  3 A- 3 A. In FIG. 3B, the upper seating surface  20  at section line  3 B- 3 B has dropped further. The upper seating surface  20  can be seen continuing its progressive drop in FIGS. 3C and 3D.  
     [0022] It has been determined that when a person stands upright, there is a passive locking mechanism at the hip joints that helps to keep the person in a stable posture by keeping the person&#39;s center of gravity at or near the body&#39;s centerline. When a person sits down, however, this locking mechanism is no longer available. As a result, the person tends to slump or slouch, which has the effect of shifting the person&#39;s center of gravity forward of the body&#39;s centerline. This results from the fact that the hips of a normal person can rotate only  50  or  60  degrees maximum, even though the person&#39;s thighs may be at a  90  degree angle to the upper torso. Since the hips are unable to rotate the full  90  degrees of bending between the thighs and upper torso, the spine is forced to bend forward which in turn shifts the body&#39;s center of gravity forward with result imbalanced pressures acting on the person&#39;s back and lumbar region. To compensate for the imbalance, the upper body is forced to seek balance in a variety of positions (such as by placing the elbows on the knees or thighs to support the weight of the upper body, or by simply slouching). However, none of these positions produce much comfort because each of them result in some amount of pressure on the lumbar discs.  
     [0023] As shown in FIGS. 4 and 5, the ergonomic seat  10  enables an occupant  24  of the seat  10  to go from a standing to a sitting position with little or no additional pressure on the occupant&#39;s lumbar discs because the seating surface  20  is angled downwardly from the rear portion  12  to the front portion  14 . Angling the seating surface  20  in this manner reduces the amount of hip rotation for the seated occupant  24 , which in turn reduces or eliminates (depending on the extent of the angle α) the amount of pressure acting on the occupant&#39;s lumbar discs. In a preferred embodiment, the angle α of the seating surface  20  is between about  10  degrees to about  30  degrees. Too steep of an angle α can elevate the rear portion  12  of the seat  10  to a level that is too high when the seat  10  is placed on a stadium bleacher  26  so that use of the seat  10  becomes less practical, while too shallow of an angle α can result in too much discomfort to the occupant resulting from pressure on the lumbar discs. The particular angle α of the seat  10  shown in FIGS. 4 and 5 is about  15  degrees, which is a more preferred angle for purposes of mass production of the seat  10  as this angle seems to provide an optimal level of practicality and pressure reduction on the lumbar discs. Individual preferences may vary, however, from the preferred  15  degree angle.  
     [0024] As described above, the seating surface  20  may be formed of a substantially rigid material, and use of such rigid material does not seem to have a significant adverse effect on the occupant&#39;s comfort. For traditional seats, the majority of any discomfort experienced by the occupant is typically a direct result of pressure acting on the occupant&#39;s lumbar discs due to a shift in the occupant&#39;s center of gravity resulting from too sharp of an angle between the thighs and the upper torso, as discussed above. However, if desired, a thin layer or pad of resilient material  28  (FIG. 4) may be positioned adjacent the seating surface  20  to further promote comfort. The pad  28  may be fabricated as a thin layer of sprayed-on foam. Alternatively, a thin layer of resilient material may be adhesively secured to the seating surface  20  to form the pad  28 .  
     [0025] It will be appreciated that a seat  10  according to the invention improves comfort to the occupant  24  by reducing bodily stress and pressure normally associated with sitting, and that such advantage is realized without the need for a back rest. If desired, however, a back rest may be utilized in conjunction with the seat  10 .  
     [0026] The foregoing description details certain preferred embodiments of the present invention and describes the best mode contemplated. It will be appreciated, however, that no matter how detailed the foregoing description appears, the invention can be practiced in many ways without departing from the spirit of the invention. Therefore, the above mentioned description is to be considered exemplary, rather than limiting, and the true scope of the invention is that defined in the following claims and any equivalents thereof.