| 摘要 |
947,010. Fluid-pressure servomotor control systems. CHERRYBURRELL CORPORATION. March 30, 1962 [April 4, 1961], No. 12256/62. Heading G3P. [Also in Division G1] The level and density of a liquid in a tank 12, Fig. 2, is sensed by a diaphragm 26 in the tank wall and supported upon a member 28 with a recessed face so forming a chamber 30; the member 28 incorporates an air inlet 32 and a bleed outlet 38 respectively leading into and away from the chamber 30. In the outlet 38 is threaded an insert 36 the outer end of which is arranged a small distance from the diaphragm. The liquid in the tank deflects the diaphragm 26 so that it closes the outlet 38 until the air pressure from the inlet 32 builds up a pressure sufficient to unseat the diaphragm from the outlet 38 to permit a bleed therethrough. Air is supplied to the inlet 32 via a diaphragm actuated pressure-regulator 44, Fig. 1, the movable closure member 48 of which is opened by a spring 60 and air pressure downstream of a restrictor 54 acting on the diaphragm in opposition to the air pressure upstream of the restrictor. Further downstream of the latter is a branch 62 leading to a monometer 64 or a pressure gauge 66 which may be calibrated to read directly the liquid level or quantity in the tank; this branch also includes high and low pressure switches 68 controlling an alarm or a pump supplying the tank. The outlet 38 is connected to exhaust either through a restriction or a back pressure regulator 72, the movable closure member 78 of which is connected to a diaphragm 82 urged towards the valve closed position by air pressure in a branch 86 from the air inlet, between the restrictor 54 and branch 62, in opposition to a spring 88 and the bleed pressure in the outlet 38. |
