GB1306710A - Hydraulic and pneumatic control systems - Google Patents

Abstract

1306710 Fluid-pressure servomotor systems FEINMECHANISCHE WERKE MAINZ GmbH 22 Sept 1970 45119/70 Heading G3P A pneumatic or hydraulic system comprises two control circuits 4, 5, 6 and 11, 12, 13 and means to change from one control circuit to the other including two mechanical couplings 7, 9 to transmit control movements to control elements 4, 11 and two by-pass valves 5, 12, resistance to movement of the control element of one of the circuits causing system pressure fluid to disengage the coupling transmitting the movement and to operate the by-pass valves. A lever 3 operates the control elements 4, 11 and provides a feedback from the output members 6, 13. The system is shown with the circuit 11, 12, 13 inoperative and with the by-pass valve 12 allowing fluid to flow freely from one side of the element 13 to the other. Resistance to movement of the element 4 disengages the coupling 7 which allows system fluid-pressure to operate both by-pass valves so that the circuit 11, 12, 13 becomes operative. The coupling 7 consists of two flanges 19, 23 connected to an input member 16 and the control valve 24, respectively, and normally constrained to move in unison by spring-loaded rings until resistance to movement of the valve causes one of the rings to be displaced and to allow system fluid-pressure from the inlet 31 to the control valve to flow through ducts 32, 33, 34 to hold the rings apart so that relative movement between the valve and the input member can occur. Fluid also flows through a line 28 to operate the by-pass valves and an indicator 8 or 10. In a modification, the fluid passages of the coupling are somewhat differently arranged within concentric sleeves (17, 18) Fig.4 (not shown). In a further modification, relative angular movement between arms (50, 51) Fig. 6 (not shown) allows pressure fluid from a passage (48 or 49) to fill a space (61) and disconnect the coupling.