Patent GB-958655-A (GB)
Title: Improvements in or relating to control devices
Inventor: KAHN PETER BRUNO
IPC: B64C29/00
Filed: 1959-12-23
Abstract: 958,655. Spring-power control devices; bearings. PLESSEY CO. Ltd. Dec. 22, 1960 [Dec. 23, 1959 (2)], Nos. 43758/59 and 43759/59. Headings F2A and F2S. A control device comprises a manually operable control element 42, Fig. 1, which is lockable in a variety of control positions and a preloadable resilient coupling member interposed between the control element and an output element 31, Fig. 2, so that the setting of the control element predetermines the final position of the output element while permitting a time lag between the setting of the control element and the completion of the follow-up movement of the output element. Clockwise movement of control lever 42 (i.e. to the right in Fig. 2) causes the end walls of slots 22, 24 to engage bushes 26 and thereby move pins 18, 19 to the right to compress spring 28. In the required operative position of the control arm 42, which may be preselected by a movable stop 70, the pin 46, Fig. 3, engages a groove 48 of the quadrant 49. The pin 17 and ring 27 are moved to the right by the pressure of spring 28 to effect movement of a control cable connected to the elements 31, 32. The cable movements may control apparatus which is used to rotate the jet nozzles of jet engines e.g. for vertical take-off or landing conditions. Movement of the sleeve 11 causes fluid flow between chambers 55A and 55B through orifices 61 under the control of a spring-loaded one-way valve element 60. Movement of the control lever 42 in an anti-clockwise direction causes fluid-flow from chamber 55B through orifice 62, past the screw thread which interengages a threaded member 64 with the hollow shaft 53 and through orifices 63 into chamber 55A. Control of the rate of piston movement may be effected either by altering the length of screw thread engagement between member 64 and shaft 53 or by providing calibrated grooves or slots in the member 64. The fluid may be supplied from a self-contained hydraulic circuit supplied from a reservoir 91, through conduit 92, cavity 89, and orifice 90 to the shaft 53. A manual override handle 73 which gives visual indication of the cable movement on graduated scales attached to the quadrant 49 is pivoted at 40 and moves a saddle plate 78 connected to sleeve 8, flange 12 and ring 30. Polytetrafluoroethylene bearings 9, 10 are provided between the sleeves 8 and 11. In another embodiment a spring-loaded portion of a control lever 111, Fig. 5, is depressed to move the control lever and thereby move a locking arm 125 through a frictional disc device. This causes movement of a pivoted catch lever 131 (Fig. 6, not shown) to release the vertical rod 126 to allow engagement of teeth 129 with a toothed rack 130 attached to an end plate 108. Further rotation of the control lever causes, through a pin 110 and plates 104 or 106, compression of springs 105 or 107. When operation of the control unit is required, a button 143 is depressed to allow teeth 129 to disengage from the rack 130. With disengagement of the inner sleeve 97 the stored energy of spring 105 or 107 moves the inner sleeve 97 with respect to the outer sleeve 105 to operate a control cable through connections 100 or 100A. The speed of movement of the inner sleeve 97 may be controlled by an hydraulic throttling arrangement (not described) associated with the device being controlled. A manual override and positional indicator lever (not shown) may be provided. The control lever of both embodiments may be formed in two sections which are pivoted together, an upper section being tilted about its pivot against a spring to disengage an indexing pin from its notch.