GB512077A - Improvements in fluid-operated piston devices for use particularly in catapults for the launching of aeroplanes - Google Patents

Abstract

512,077. Pneumatic railway systems., MERZ, F. April 22, 1938, No. 12133. Convention date, April 22, 1937. [Class 104 (ii)] [Also in Group XXXIII] A fluid-operated piston device for launching aircraft, conveying railway trucks or elevator cabins &c. comprises a lateral arm on the piston projecting through a slot on its cylinder, this slot being elsewhere sealed by a longitudinal ribbon which is caused to follow a smooth path defined by the surfaces of the piston and the arm, which arm is in the form of a longitudinal. web. The ribbon 5 may be crescent-shaped, Fig. 4. The tubular double piston 6, 6', of which three may be provided in parallel bores in a cylinder, the pistons being connected externally, transmits thrust to a central tube 8 connected by a web 10 extending through the slot 3 with the force transmitting member 9 which is linked by rods 13 with the launching &c. carriage 15 to be moved. The carriage is provided with brakes comprising metal sheets 37, Fig. 7, on the carriage, clamped between external jaws under air pressure and an internal member 41 either stationary or sliding a short distance. Air or explosive gas is admitted to move the pistons by a valve 24 operated by a piston 26 to which air is admitted by opening a valve 27; the valve 27 also operates a valve 42 to release the brakes. An adjusting valve 25 is gradually opened to its maximum extent by the motion of the carriage. At a certain point, a cam 29 actuated by the motion of the carriage opens a valve 28 admitting air to the piston 26 to operate the valve 24, closing the inlet 48 and opening the outlet 49. Immediately afterwards air or gas is admitted to the other end of the pistons which are brought to rest under this action and the action of the brakes at the outer end, the sliding member of which may close the air inlet and open the outlet at this end. To return the carriage to the launching end, the brakes at the other end are released and the adjusting valve at this other end throttled, and air is then admitted to move the pistons, which are stopped as before. A motor-actuated chain and sprocket device, afterwards brings the carriage back to the exact starting position.