| 摘要 |
<p>1,156,126. Valves. SVENSKA PRECISIONSVERKTYG A.B. 29 Aug., 1967 [14 Nov., 1966], No. 39451/67. Heading F2V. [Also in Division G3] Rise of conductive liquid to a predetermined level in an auxiliary chamber communicating with a main chamber is detected so that an electric motor-driven pump is started to exhaust the main chamber and, by its operating pressure, causes expansion of a tube of resilient material against the internal wall of a cylinder to seal the remainder of the air in the auxiliary chamber so that the pump operates until the level in the main container falls to a low value. In Fig. 1, when the level of a conductive liquid, e.g. contaminated water, rises within auxiliary chamber 13 sufficiently to bridge electrodes 20, 21, an electrically driven pump is started to extract water from the main container (not shown). The operating pressure of the pump is effective at 3 to cause expansion of a thimbleshaped membrane of oil resistant rubber 102 against a sleeve 100 so as to seal the vent otherwise provided through sleeve 100 and channels 110, 111, 108. In consequence, the pump continues in operation until the level in the main container falls sufficiently to uncover an outlet in the lower part of chamber 13 (not shown) so that the level in chamber 13 can fall. Contours 104 are provided within sleeve 100 so that operation of the valve generates a self-cleaning action. Sleeve 10, which is sealed by 0-rings 118, is removable for inspection and cleaning. In a modification, the membrane is held in the lower part of sleeve 100 and is pushed over another sleeve projecting through the wall of chamber 13 so that both sleeve 100 and the membrane are removable from above. In this arrangement, the vent is completed through holes in sleeve 100 in an area experiencing further self-cleaning action. A float-operated switch may be used instead of electrodes 20, 21 to initiate operation of the pump, and the membrane may be a gas-filled envelope.</p> |
