| 摘要 |
<p>A gas-operated, double diaphragm pump comprises a pair of diaphragms (6,8) secured to, to be movable with, a shaft (4) under the control of a valve (18) which supplies gas under pressure alternately to the diaphragms (6,8) whereby the diaphragms (6,8) create a pumping action. The control valve (18) includes a hollow chamber (22) having an inlet (24), first and second outlets (34,38) feeding to the diaphragms (6,8) and an exhaust outlet (36), a control member (40) movable within the chamber (22), and a bearing member (54) mounted in, to be movable with, the control member (40) and urged into sealing contact with the inner wall of the chamber (22). The arrangement is such that, on movement of the control member (40) and the bearing member (54), the gas inlet (24) is alternately interconnected with the first and second outlets (34,38) while the gas outlet not being supplied by the inlet (24) is interconnected with the exhaust outlet (36), the bearing member (54) sealing the gas outlet being supplied by the inlet (24) from the exhaust outlet (36) and from the other gas outlet.</p> |
