585,265. Parachutes. QUILTER, J. R. C. Feb. 15, 1945, No. 3817. [Class 4] Automatic parachute control apparatus comprises a barometric device operating through a servo-motor or power actuated means to withdraw the rip-cord pin or pins so as to effect release at a predetermined height after falling from the aircraft, the operation of the apparatus being initiated by the withdrawal of a locking device, closing of a switch or equivalent setting action when the pilot is leaving the aircraft. In one form, Figs. 1, 3 and 4, the barometric device comprises a stack of capsules 13 fixed at one end to. a post 14 which extends through the cover 12 of a bell-shaped housing 11 enclosing the capsules. The movable end of the stack carries a rod 15, passing freely through the wall of the housing and carrying an adjustable collar 18 having a serrated edge adapted to make contact with a bar 16 secured to the housing. The bar is connected by a wire 49 to one pole of a plunger switch 48, the other pole of the switch being connected by a wire 47 to a plate 33 which is in contact with one pole of a battery 38. The switch is normally maintained open against the action of its spring 55 by a locking pin 57 attached to the static line of the parachute. The other pole of the battery is engaged by contact strips 41 connected by wires 43 to the outer two of four terminals 35 connected to two pairs of leads 36 from two detonator cables 37. The inner two terminals are connected by a common lead 44 to the post 14 and through the capsules to the collar 18. If the pilot leaves or is ejected from the aircraft at a high altitude, the static line is pulled and the pin 57 withdrawn to allow the switch 48 to close. When the pilot has fallen to a predetermined height, the capsules 13 collapse under the bar 16 to close the circuit of the detonator cables 37. These cables are connected to the firing bridges 158 of a cartridge 59, Fig. 5, comprising a propellant charge 60 enclosed in the base of a shell 61. The bridges are embedded in a gunpowder charge 65 which is separated from the charge 60 by delay composition 66 giving a two-second delay between firing of the gunpowder and explosion of the propellant. The gases produced by the explosion enter a cylinder 64 and act on a piston 68 secured to the rip-cord 69 to withdraw the rip-cord pins 71. The cord 69 is also attached to a manual release handle 72. The barometric device and the cartridge are mounted on base plates provided with apertures to enable them to be stitched to the parachute harness, see Fig. 6 (not shown). In another form, Fig. 8, the movable ends of a series of capsules 78 carry a friction member 80 normally in braking contact with the balance wheel 81 of a clockwork mechanism 82. The mechanism comprises a pinion 84 meshing with a toothed rack 85, the extremity of which forms a latch 86 for an arm 87 engaged by a powerful spring 89. The rip-cord 90 passes through the spring and a hole in the arm, adjacent to which it is fitted with a collar 91, and is attached to a handle 92 for manual release. The balance wheel 81 is also braked by a pad 95 maintained in contact by a locking pin 94 which is releasable either by the static line 96 or a manually-operable lever 97.
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