Patent GB-713427-A (GB)
Title: Improvements in or relating to automatic flow regulators for liquids
IPC: B64D37/14
Filed: 1950-11-17
Abstract: 713,427. Fluid-pressure servomotor-control systems. GLOSTER AIRCRAFT CO., Ltd., and LONGFORD, C. G. Nov. 13, 1951 [Nov. 17, 1950; June 19, 1951], Nos. 28165/50 and 14526/51. Class 135 Means for maintaining substantially constant the ratio of the rates of flow from two or more liquid supplies and described as controlling fuel flow from a number of tanks in an aircraft comprises a throttle valve in at least one supply actuated by a pressure responsive member the pressure applied to which is controlled by means actuated jointly by a displaceable element in each supply. The embodiment shown comprises a throttle valve 18 in each of two supply ducts 13, 14, spring-loaded plates 30, 30A responsive to the rate of flow from the supply ducts to a common outlet 15, and a control-valve plate 43 movable in response to a deviation in the ratio of the fuel flows to close or partly close one of two outlets 28, 28A from diaphragm chambers 23, 23A which are supplied with fuel under pressure through restricted passages 26 connecting with the supply ducts whereby the corresponding diaphragm moves a throttle valve towards its seat to restore the ratio of the flow rates. The valve plate 43, which is carried on a forked lever 40 pivoted at 41 and carrying a damping vane 45 and a balance weight, is actuated by a T-shaped lever 36 engaged by the ends of levers 32, 32A which carry the flowresponsive plates 30, 30A. An increase of flow which does not alter the ratio results in an upward movement of the lever 36 without tilting and, therefore, without operation of the valve plate 43. The throttle valves 18 are connected to their diaphragms 21 by springs 11 so that in the event of no fuel being available from one of the supply ducts resulting in a closing movement of the diaphragm and throttle valve of the other duct, fuel can flow from the latter duct by moving the throttle valve against its spring. The ratio of the flows can be varied by altering the position of the pivots 33, 33A of the levers 32, 32A. In a modification, three flow responsive devices are interconnected with a spherically pivoted lever which carries a control-valve plate coacting with the outlets from three diaphragm chambers actuating throttle valves in three supply ducts. In a further modification, in which flow from four ducts is controlled, each throttle valve and diaphragm has a separate control-valve plate actuated in part by the corresponding flowresponsive plate and in part by linkage connected with all of the flow-responsive plates. According to the first Provisional Specification, in an arrangement for controlling two flows, the flow responsive plates are carried on the ends of a leaf spring mounted at right-angles to a lever having a flat extremity which moves between two nozzles constituting outlets from two bellows to which air under pressure is supplied. Each bellows operates a throttle valve. Alternatively, the belows may be connected to the supply ducts instead of to the air supply, and in this case, to ensure that if the supply in one duct should fail the other duct is not automatically closed, the connections between the ducts and bellows are such that each passes from one duct to the bellows which operates the throttle valve of the other duct. According to the second Provisional Specification, the last arrangement is modified in that the bellows, instead of operating the throttle valves directly, control outlet nozzles from chambers associated with diaphragms which operate the throttle valves.