Patent GB-830045-A (GB)
Title: Improvements in and relating to control devices controlling the opening of a parachute container
IPC: B64D17/52
Filed: 1957-02-14
Abstract: 830,045. Parachutes. ETUDES ET FABRICATIONS AERONAUTIQUES. Feb. 14, 1957 [Feb. 16, 1956; June 29, 1956], No. 5060/57. Class 4. A device controlling the opening of a parachute container comprises automatic release mechanism at least some of which acts automatically when the wearer jumps, and carried by a handle used for manually opening the container, the mechanism and handle being combined with a single flexible rip cord which extends freely into a chamber in the handle and there ends in an abutment, wherein a piston is provided in the chamber between the abutment and an end wall of the chamber, and the automatic mechanism is adapted to act on the piston to engage it with the abutment, whereby the rip cord may be pulled by pulling manually on the handle or by the action of the automatic means. In one embodiment, Fig. 4, the rip cord 2 is attached to pins in conventional cone and grommet fastenings on the pack (not shown) and slides in a sheath 3 attached to a metal and piece 4 secured to a harness strap b by wires 7 and forming an abutment for a threaded end cap 11 screwed into the manual release handle 5. A piston 14 slides in a bore 9 in the handle, and the cord 2 passes through the piston and ends in a nipple 13 engageable by the piston. Bore 9 communicates through port 22, channel 21, and port 20 with a second bore 10 containing an explosive charge 25, combustible fuse material 26, a detonator 27, and a firing pin 28 on a rod 29 urged towards the firing position by a spring 38 and formed with an eye 31 engaged by a hook 32 pivoted to a rod 34 ending in an eye 35 attached to a static line 36. When the parachutist jumps, line 36 pulls rod 35 until the hook 32 is clear of bore 10, when the hook disengages from eye 31 and the firing pin is urged by spring 38 to detonate the charge, the fuse material 26 providing a time delay. The explosion drives piston 14 to engage the nipple 13 and pull the rip cord. Alternatively the user may pull the rip cord by traction on handle 5. In the embodiment of Fig. 8, the handle comprises a tubular portion 44 having a bore 49, and a bowed portion 45. The piston 48 in bore 49 is engageable with the nipple 13, and is urged to pull the rip cord 2 by a spring 46, but is normally restrained by a ball 50 maintained in engagement with a collar on the piston by a wheel 52, which is urged to rotate by a spring 53, but restrained by a pawl 59 engaging a ratchet wheel 57. On jumping, the static line 36 shears a pin 60a and withdraws pawl 59, when the wheel 52 rotates until a recess 55 opposes ball 50, when the ball is retracted and the spring 46 expands, pulling the rip cord. By clutching a hand lever 67 pivoted at 68 to the handle, the user can engage a pawl 63 with a ratchet wheel 61, preventing rotation of wheel 52 until pawl 63 is withdrawn by a spring 65 when lever 67 is released. The user may thereby obtain free fall. In Fig. 13, a rack 86 on piston 82 engages a pinion 90 connected by a gear train to an escapement wheel 95 co-operating with an anchor (not shown). The escapement wheel is prevented from rotating by a pawl 98 on a lever 99 pivoted to the handle at 100 and held in the engaging position by a pin 102 normally held in a bore 103 in the handle by an elastic split ring 104 and abutting a flange 101 on lever 99. When the user jumps, the static line 36 withdraws the pin, as shown, and pawl 98 is withdrawn by spring 105. The escapement wheel rotates until a radial lever 113 thereon abuts a projection 112 on a lever 110 controlled by a barometric capsule. When the user is below a pre-set altitude, the capsule withdraws lever 110, and the escapement wheel is free to rotate under the control of the anchor. A spring 85 then drives the piston 82 and rotates the pinion 90 at a speed governed by the escapement wheel, until rack 86 disengages from pinion 90, when the spring expands rapidly, and piston 82 engages the nipple 13 and pulls the rip cord.