| 摘要 |
<p>A seat cushion (10) features an inner core (13) of open-celled compressible foam material hermetically sealed within a first inner cover (14) which is of a size to fit loosely about the inner core (13). An outer cover (16) is of a size and shape substantially as that of the inner core (13) and is nominally larger to allow the material of the inner cover (14) to shift within a space between the inner core (13) and outer cover (16). A tube (15) incorporating a valve (19) leads from the space within the inner cover (14) through the covers to the atmosphere. The cushion (10) is naturally self-inflating when the valve (19) is open so it need not be blown up by the user with his or her lungs or other air source. A sitter on the cushion (10) can adjust its compressibility by opening the valve (19), or deflate the cushion (10) entirely for storage or for portability, then close the valve (19) to maintain the cushion closed.</p> |
