Patent GB-749459-A (GB)
Title: Improvements in or relating to ejector seats for aircraft
IPC: B64D25/10
Filed: 1953-06-17
Abstract: 749,459. Ejector seats for aircraft. SOC. NATIONALE DE CONSTRUCTIONS AERONAUTIQUES DU SUD-QUEST. June 17, 1953 [July 31, 1952], No. 16753/53. Class 4. An ejectable seat equipment for aircraft comprises a hollow seat, a parachute pack forming a cushion in said seat, a parachute harness for securing said parachute pack to the occupant of the seat, said harness including seat attachment straps one end of each of which is secured to said harness while the free end thereof cooperates with locking means fast with the seat and actuated by an elastic force controlled by a time delay mechanism carried by the seat, the parachute pack being secured to the seat only by reason of the fact that it is secured to the harness which is attached to the seat. The pilot is normally secured to his seat by releasable connections between his harness and the seat, such connections being released automatically when the seat is ejected. The harness comprises two shoulder straps 28, two waist straps 31 and a single strap 33 passed between the pilot's legs, the straps 28 having buckles 29 engaged by bands 39 mounted on rollers 40 on a yoke 41 which is spring loaded so that the pilot is normally held against the seat back but is free to move forwardly against the action of the spring acting on the yoke 41. The upper ends of the bands 39 and the ends of the harness straps 31 and 33 are retained in locks 51 and 37 (Figs. 9-12, not shown), each comprising an axially movable sleeve surrounding and retaining a ring of balls in a circumferential groove in a central member secured to each strap, axial movement of the outer member releasing the balls so that the central member can be withdrawn. The releasing mechanism comprises a unit 46 formed with a cylinder 70 housing a piston 47b loaded by a spring 69, the piston having a slotted extension 47a and protruding lugs 71 engaged by arms of pivoted levers 72, 73, the other ends 72a and 73a of which are engaged by rollers 74 on the ends of levers 75, 76 so that the spring 69 is normally held compressed. ' The levers 75, 76 are freely mounted on a pivot 77 and are respectively connected by piston rods 78, 81 to a barometric capsule 79 and a spring loaded liquid dashpot 82, the spring of the dashpot being normally held compressed by a key 86 in a slot on the rod 81, the key having a static line 88 secured at its other end to the aircraft structure. When the seat is ejected, the key 86 is withdrawn thus freeing the dashpot device to release the lever 73. Lever 72 is released by the barometric device 79 at the correct altitude and thereafter spring 69 moves extension 47a which acts through a lever 49 and rod 50 to free the locks 51 and through rod 52, lever 53, rods 54 and 58, lever 59 and rods 60, 64 and 66 to release the locks 37. The mechanism 55, 56, 57 is provided to permit vertical adjustment of the seat and an emergency manual release mechanism 67, 68 is provided. An automatic release mechanism (Fig. 13, not shown) is described for releasing the pilot's parachute after he becomes separated from his seat. Specifications 652,131, 673,147 and 707,915 are referred to.