| 摘要 |
This invention relates to a seat, couch or bed, provided with at least one vacuum cushion comprising an air-tight flexible envelope containing a coherent porous mass or resiliently compressible intercommunicating open cellular material, having an inherent rigidity capable of substantially supporting the weight of an occupant without collapsing , a vacuum source, pipes for connecting the interior of this envelope with said vacuum source and with an ambient environment, at least one valve for selectively opening or for shutting off these communications with the envelope, in order to control the thickness of the cushion independently of the occupant's weight, and for the purpose of directing the compression of the porous mass in the direction of its thickness and facilitating the evacuation of the air contained in the cells of the porous mass when the envelope is in communication with the vacuum source, an additional air-permeable layer which allows, whatever stress is exerted on this additional layer, the circulation of air through same, between the porous layer and the pipe of the valve communicating with the vacuum source, this pipe discharging into this additional layer, said additional layer being provided in the envelop on that face of the porous mass opposite the face on which the occupant's weight is applied. |
