GB418776A - Improvements in or relating to latch gear for folding wing aircraft - Google Patents

Abstract

418,776. Aircraft wings. BLACKBURN AEROPLANE & MOTOR CO., Ltd., Seaplane Base, and PETTY, G. E., Pantiles, both in Brough, near Hull. Aug. 17, 1933, No. 22971. [Class 4.] In aircraft having wings hinged to the fuselage to facilitate folding and latches for maintaining the wings in their flying position a fluid-pressure. operated control is provided for effecting movement of the latches into and out of their operative positions. As shown and as applied to a biplane, a reservoir 10 communicates by means of a conduit 12 with pumps 13, 113 mounted on the centre section 14 of the lower wing and controlling, respectively the latches on the port and starboard side of the aircraft. The pumps 13, 113 communicate, respectively, with cylinders 16, 116 on the lower wings and cylinders 17, 117 on the upper wings. The various pipes pass up the front of the fairings of wing-struts 20, 120, 22, 122. The rear spar 23 of each wing is provided with a hinged joint 24 and the front spar with a joint 27, 28 held in operative position by a latch pin 29 constituting an extension of a plunger 30 movable within, e.g. the cylinder 16. The latchoperating mechanism for the upper wing is located on the movable part of the wing, the fluid supply conduit for the cylinder 17 being looped behind the rear wing spar. When the handle of a pump 13 is pulled, fluid passes into the cylinders 16, 17 through pairs of admission vents 36, 136 to force pistons 37 on the plungers 30 to the left against the action of a pair of springs 33, 34 to withdraw the latch pins. Each plunger carries screw-threaded extensions 38 provided with a stop collar 39 which co-operates with a safety trigger 40 which is released on actuation of the pump by movement under fluid-pressure of a piston 46 against the action of a spring 48. The stop-collar 39 is screwed onto the extension 38 and is locked in position by a nut 51 ; thus on failure of the hydraulic gear the latches may be withdrawn by removal of the nut 51 and rotation of the stop collar. Return of the latch pins may be assisted by hydraulic means, the pumps may be locked so as to hold the latches inoperative, and the apparatus may be applied to a monoplane.