Patent GB-875296-A (GB)
Title: Improved jet propulsion nozzle
Inventor: KEEN JOHN MICHAEL STORER
IPC: F02K1/15
Filed: 1958-12-04
Abstract: 875,296. Jet-propulsion nozzles. ROLLSROYCE Ltd. Nov. 26, 1959 [Dec. 4, 1958], No. 39141/58. Class 110 (3). A jet-propulsion nozzle is provided with two members such as the flaps 10, 11, each of which is associated with and is moved by means of a fluid-operated double-acting ram 18, 19 between a closed and an open position to vary the effective nozzle area and a control mechanism which may be set so that both members are closed or one member open and one closed, or both members open. In take-off condition, with the flaps closed, a throttle lever 39 is in the position shown in Fig. 1, to the left of a detent 53 so that a contactor 49 cannot bridge contacts 47, 48, thereby maintaining a solenoid 45 de-energized to close a vent 41 by a valve 42. A link 38 moves a two position valve (not shown) so that pressure fluid is fed to one end of a double-acting cylinder 21 via conduits 22, 23, and to one end of a double-acting cylinder 20 through a change-over valve device 25 and a passage 36. The opposite ends of the cylinders 20, 21 are vented to the atmosphere via a conduit 32; the former through the pipes 34, 35, and the latter through the pipe 33. As the vent 41 is closed the piston surfaces 67, 68 of a shuttle valve 26 are vented to the atmosphere through the conduit 32 and pressure fluid from the conduit 22 acts on a piston surface 66 and the shuttle valve 26 is maintained to the right. With both flaps closed contacts 62, 63 are closed to illuminate a warning light 65 but another light 64 will not be lit since the contacts 47, 48 are open. After takeoff the throttle lever 39 is moved to the right of detent 53 and the linkage 38 moves the twoposition valve so that pressure fluid is fed to the conduit 32 and the conduit 22 is vented to atmosphere. The contacts 47, 48 remain open due to latch 52 and the solenoid 45 deenergized. Pressure fluid from the conduit 32 moves the ram 19 to the left opening the flap 11 and opening contacts 63 to extinguish the light 65. Further pressure fluid flows through the pipe 34 and the passage 40 to act on the piston surfaces 67, 68, 69 and move the shuttle valve 26 to the left. Pipe 34 then communicates with the passage 36 and the passage 35 communicates with the ram 18 and the atmosphere through vent 37. For normal cruise setting a spring- loaded catch 52 is released to close the contacts 47, 48, thereby illuminating the light 64 and energize the solenoid 45, to open the vent 41. Pressure fluid from the passage 40 is vented to atmosphere and as the passage 40 is of smaller diameter than the pipe 34, the fluid pressure in the latter is greater than that on the piston surface 68. The shuttle valve moves to the right to admit pressure fluid to the passage 35, thereby causing the ram 18 to move to the left to open the flap 10 and the contacts 62 and extinguish the light 64. Hence with the throttle lever to the right of the detent 53 either high-speed cruise or normal cruise may be selected. A " fail-safe " construction is thereby provided as failure in the solenoid circuit will only prevent normal cruise condition being attained.