| 摘要 |
<p>PCT No. PCT/GB83/00023 Sec. 371 Date Sep. 26, 1983 Sec. 102(e) Date Sep. 26, 1983 PCT Filed Feb. 1, 1983 PCT Pub. No. WO83/02987 PCT Pub. Date Sep. 1, 1983.A valve comprises rolling diaphragm (7) supported at its outer periphery by an annular support member (8) within which the diaphragm rolls in response to inlet pressure so as to uncover an outlet opening (20) in the support member, thereby to allow the escape of said pressure. Preferably, the diaphragm (7) is annular and is supported at its inner periphery by a guide member (9) that engages on abutment (19) when the outlet opening (20) is closed by the diaphragm, and that guides the diaphragm as it rolls back and opens the outlet opening (20). Preferably, the outlet opening (20) is of reduced width towards that part which is first uncovered by the diaphragm in operation. The valve may include a two part housing (1, 4) with the support member (8) located between the two parts and with the outer periphery of the diaphragm (7) gripped between one part of the housing (4) and the support member (8).</p> |
