Patent Publication Number: US-2004055090-A1

Title: Seat cushion structure

Description:
FIELD OF THE INVENTION  
       [0001] The invention relates to a seat cushion structure and, more particularly, to a seat cushion structure that can provide comfortable seating and good heat dissipation.  
       BACKGROUND OF THE INVENTION  
       [0002] As shown in FIG. 1, a conventional stool is usually provided with flexible cushion  1  that has an upper surface on which the buttocks of the sat user rest. The cushion  1  is conventionally made of a foamed material  2  that is outwardly covered with a covering skin  3 . If the user seats on the cushion  1  for a long time, the heat from the user&#39;s body is progressively transferred to the foamed material  2  of the cushion  1 . If the covering skin  3  is made of synthetic leather, it is not air permeable. When the user seats on the cushion  1  for a long time, the heat is therefore accumulated at the contact interface, which causes uncomfortable sweating.  
       [0003] The above disadvantages are exacerbated when the user while being seated is moving. This occurs when the user is, for example, a drummer who is practicing. The consequent movement of the drummer&#39;s buttocks creates frictional contacts and increases the production of heat. Furthermore, the upper planar surface of the cushion  1  is usually not adapted to the curved profile of the profile of the user&#39;s buttocks. As a result, the support of the user&#39;s weight is substantially concentrated at a limited contact area of the cushion  1 , which causes fatigue during prolonged seating time.  
       SUMMARY OF THE INVENTION  
       [0004] Accordingly, it is a principal object of the invention to provide a seat cushion structure that can provide comfortable seating and good heat dissipation.  
       [0005] To attain the above and other objectives, a seat cushion structure of the invention comprises a cushion body, made of a foamed material, that has a top surface provided with two recessed cavities. A flexible filling material is filled within the recessed cavities of the cushion body. A covering skin is stretched to outwardly cover the flexible filling material and the cushion body, wherein an air gap is left between the flexible filling material and the covering skin.  
       [0006] With the above seat cushion structure, comfortable seating is provided. Furthermore, an air gap is maintained between the covering skin and the filling material even when the sat user is moving, which therefore improves the heat dissipation.  
       [0007] To provide a further understanding of the invention, the following detailed description illustrates embodiments and examples of the invention, this detailed description being provided only for illustration of the invention.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0008] The drawings included herein provide a further understanding of the invention. A brief introduction of the drawings is as follows:  
     [0009]FIG. 1 is a perspective view schematically illustrating a seat cushion structure of the prior art;  
     [0010]FIG. 2 is an exploded view schematically illustrating a seat cushion structure according to an embodiment of the invention;  
     [0011]FIG. 3 is a perspective view schematically showing the external aspect of a seat cushion structure according to an embodiment of the invention;  
     [0012]FIG. 4 is a cross-sectional view taken along the section  4 - 4  of FIG. 3; and  
     [0013]FIG. 5 is a perspective view schematically illustrating the assembly of the seat cushion structure of the invention a stool. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
     [0014] Wherever possible in the following description, like reference numerals will refer to like elements and parts unless otherwise illustrated.  
     [0015] Now referring to FIG. 2, the invention provides a seat cushion structure that comprises a cushion body  10  made of polyurethane (PU) foamed material. At the left and right sides of the top surface of the cushion body  10  are respectively formed recessed cavities  11  that respectively have a profile compliant to the profile of the user&#39;s buttocks. A covering skin  12  made of, for example, leather material, is stretched to outwardly cover the cushion body  10 , the covering skin  12  being partially in contact with the top surface of the cushion body  10 . The recessed cavities  11  are filled with a flexible filling material  13  made of, for example, silicon resin that has a top surface spaced away from the covering skin  12  by an air gap L (see FIG. 4).  
     [0016] Referring to FIG. 3 and FIG. 4, when the user seats on the cushion body  10 , due to the user&#39;s weight, his/her buttocks are received within the recessed cavities  11  and the filling material  13  flexibly matches with the profile of the buttocks. Comfortable seating is therefore provided via an increased contact surface area. The covering skin  12  is preferably air-permeable and further provided with adequate elastic properties so that it is capable of stretching and contacting with the filling material  13  under pressure of the user&#39;s weight even if the user&#39;s buttocks are moved on the cushion body  10 . The movement of the user&#39;s buttocks may be significant in certain situations such as when the user is a drummer who is practicing, in which case the cushion structure of the invention provides more particularly comfortable seating.  
     [0017] When no pressure is exerted thereon, the covering skin  12  is further capable of separating from the surface of the filling material  13  to substantially restore the air gap L there between. The air gap therefore provided, even when the covering skin  12 , under pressure of the user&#39;s weight, stretches and contacts with the filling material  13 , can dissipate the heat from the user&#39;s body transmitted through the seat contact to the cushion body  10 . Furthermore, the heat is all the more rapidly dissipated as the filling material  13 , made of polyurethane, does not easily retain heat, which promotes head dissipation through the air gap and the air-permeable covering skin  12 . Therefore, a cool and comfortable feeling is obtained when the user seats on the cushion body  10 .  
     [0018] It should be noticed that the two recessed cavities  11  are designed in accordance with the profile of the human buttocks and their specific curvature, which therefore enables an optimal pressure distribution of the user&#39;s weight at the contact interface with the cushion body  10 . As shown in FIG. 5, the foamed material of the cushion body  10 , formed in a single body, is relatively cheap and further is sufficiently hard to be capable of supporting the user&#39;s weight without substantial deformation. Although the filling material  13 , preferably made of silicon resin, is relatively more expensive, its amount in the entire seat cushion structure is however reduced compared with the foamed material of cushion body  10 . The seat cushion structure of the invention can be therefore produced with a relatively low manufacture cost.  
     [0019] As described above, the invention therefore provides a seat cushion structure that can economically provide comfortable seating and good heat dissipation characteristics. The seat cushion structure comprises a cushion body that is provided with two recessed cavities formed in accordance with the profile of the human buttocks. The recessed cavities are filled with a filling material, and both cushion body and filling material are outwardly covered with a covering skin, wherein an air gap is left between the filling material and the covering skin.  
     [0020] To achieve comfortable seating, the material of the filling material is preferably made of silicon resin. However, the use of other types of material may be also envisaged for the filling material such as sponge materials.  
     [0021] Those skilled in the art will readily appreciate that the above description is only illustrative of specific embodiments and examples of the invention. The invention should therefore cover various modifications and variations made to the structure of the invention described herein, provided they are included within the scope of the invention as defined in the following appended claims.