Patent GB-849496-A (GB)
Title: Improvements in or relating to aircraft ejector seats and canopy releases
IPC: B64D25/10
Filed: 1956-09-24
Abstract: 849,496. Ejection seats and canopies on aircraft. FOLLAND AIRCRAFT Ltd., CONSTANTINE, A., and MARSH, J. Dec. 24, 1957 [Sept. 24, 1956], No. 29183/56. Class 4. In a combined canopy release and seat ejector mechanism on aircraft the ejector seat 11 has a pilot's head rest 12 and a face blind (not shown) provided at one end with a handle 14 and at the other end with a cable to operate the firing mechanism 16 of ejection gun 49. The blind has a further cable connection 32 with a rotary drum 17 having a one-way drive with a torque shaft 18 and mounted on the back of the seat. Shaft 18 carries at one end a sprocket 24 connected by chain 25 and cables 26 to a further sprocket 27 which has a chain and cable connection 29, 30 with a double-arm lever 52 connected to a second lever 53 connected by a push-rod 54 to a lever 55 which operates a releasable catch 56 for the port side of the front of the cockpit canopy 57. Catch 56 operates linkwork 58-64 to operate a similar catch 65 on the starboard side, and both catches are held normally locked by the provision of a roller 94 which engages a tail 93 on lever 53, the roller being on an arm 95 fast with a further arm 97 which is biassed by a coil spring 96. Operation of drum 17 and sprocket 24 by blind is initially limited to the amount necessary to free the front catches 56, 65 only by the provision of an abutment 85 on drum 17 which is engaged by a lever 84 pivotally connected to the lower end of a push rod 83 having at its upper end a roller 81 engaged by a bracket 80 until the canopy has swung upwardly and rearwardly to a position where it will automatically become free from its rear hinges. Each such hinge comprises a catch 67 pivoted to the aircraft at 68 and formed with a tail 69 which underlies a roller 70 on a bracket 71 fast with the canopy so that catch 67 cannot be released as long as the canopy occupies a normal position on the aircraft. When the front catches 56, 65 are released the canopy will swing about rear hinge pin 72 which is engaged by the catch 67, and roller 70 will thus be freed from tail 69. A cam 73, pivoted at 75 to catch 67, carries a roller 74 which engages a cam 179 mounted on the aircraft and is formed with a cam slot 76 which enlcoses a pin 77 on the aircraft and is further pivotally connected at 78 to a rod 23 attached at its lower end to a lever 22 actuated by a cam 21 fast with shaft 18 and drum 17, such actuation being permitted only after roller 81 is free of bracket 80. A beak 79 secured to the canopy overlies roller 74 and as the canopy swings open the beak bears on roller 74 and pushes it down the surface of cam 179, the cam 73 hinging for this purpose about pivot 78 on rod 23. In consequence, and through connection 75, catch 67 is swung clockwise as viewed in the Figure and releases hinge pin 72. Mechanism 100, 101 is provided for releasing the front catches independently of operation by the face-blind. The seat frame is tubular and is guided for ejection from the aircraft by fore- and-aft and laterally disposed sets of rollers.