GB384758A - Means for operating rotating wings or rotors of aircraft - Google Patents

Abstract

384,758. Starting rotary-wing systems. POBJOY, D. R. and POBJOY AIRMOTORS, Ltd., Hooton, Wirral, Cheshire. Nov. 2, 1931, No. 30374. [Class 4.] For connecting an aircraft engine to rotating wings, for example at starting, a ratchet clutch is moved by a lever which releases a brake on the rotor shaft before effecting the engagement of the clutch and releases the clutch before braking the rotor shaft. Should the rotor shaft overrun the engine shaft the ratchet teeth of the clutch enable slipping to take place. Two clutch members 54, 55 are normally held apart by oil pressure acting on a spigot 61, the part 55 being carried on a sleeve 56 splined to a shaft 58 having a bevel wheel 60 in mesh with a bevel wheel 8 on a vertical shaft carrying a sun pinion 6, Fig. 3. A lever 65 moves the shaft 56 to engage or disengage the clutch and is actuated by a rod 66 connected through interposed springs to a lever on a vertical shaft 48. The sun pinion 6 meshes with three planet pinions 9 carried by shafts on a disc connected to the rotor shaft 16, and provided with a brake drum. A second brake drum 2 is provided on a member having upper and lower rows of internal teeth meshing with toothed members 12 on the pinions 9. This drum has a brake band 19 tightened by pins on the ends of levers 26, 27 linked together at 28 and normally forced apart at their outer ends by springs 35, 36 in cups 31, 32. These cups are pressed together to free the planetwheel carrying-member by levers 38, 39 engaging cams 45, 46 on the shaft 48 which is provided with a hand-lever and locking quadrant. A band brake on the rotor shaft drum is actuated by levers 51, 52, Fig. 1, on the upper end of the shaft 48 and is released as the brake 19 is applied to render the epicyclio gear effective. In the neutral position of the lever both brakes are off, and when moved to start the rotor the clutch is engaged before the brake 19 becomes tight. According to the Provisional Specification the clutch is engaged when the rotor brake is applied, and when the hand-lever is moved in the opposite direction to lock the planet carrier and release the rotor brake the clutch lever, which has a lost-motion connection to the hand-lever, is left behind.