Patent GB-488621-A (GB)
Title: Improvements in or relating to parachute flares
IPC: F42B10/56
Filed: 1937-01-08
Abstract: 488,621. Parachute flares ; dropping flares from aircraft. DRIGGS, jun., L. L. Jan. 8, 1937, No. 644. Addition to 395,126. [Class 9 (ii)] An aeroplane parachute flare of the kind described in the parent Specification, and comprising a parachute and flare adapted to be expelled as a unit, with the parachute unopened, from a hermetically-sealed container, is so arranged that the parachute and flare are separated on ignition of the flare, which can only be effected after the expulsion of the unit from the container, and after the lapse of a predetermined time for slowing down the unit by air-resistance, relatively to the speed of the aeroplane. A small and strong pilot parachute may be combined with the device, to slow down the unit, to assist the main parachute to open, and finally to float the empty container of the main parachute to earth. As shown, the flare casing 1 is provided at its lower end with a removable cap 2 and at its upper end with a fixed conical cap 3 by means of which it is secured in a vertical position on an aircraft. The casing 1 encloses the flare 4 in its casing 5, the main parachute 6 in its casing 7 and, if desired, an auxiliary parachute 8 housed in a recessed portion of the casing 7 to which it is attached by a stout suspension cable (not shown). The suspension cable 9 of the main parachute is connected to an eye-bolt 10 on the casing 5. A spring locking ring 12, consisting of two semi-cylindrical halves locked together by two diametrically opposed longitudinally-withdrawable pins, is provided with studs 11 which engage in recesses or holes in extensions 13, 14 on the casings 5 and 7, respectively, so as to lock these casings together. The pins securing the ring 12 are connected by a pair of metal rods or strips to the flange of a cap 17 enclosing the fuze mechanism in the end of the flare. This cap is mounted on a wooden fuze block 18 and retains a circular cork seating disc 19 and an annular cork washer 20. The block 18, which is provided with a central well 21 closed by a seal 22, is transversely bored from both sides so as to accommodate metal thimbles 23, 24 containing igniter compositions adapted to ignite, through delay fuze elements 25, 26, a booster composition 27 keyed in the end of the flare signal composition. Matches 28, 29 in frictional contact with the igniter compositions are attached to the seal 22 which carries a ring or loop 30 connected by a cable 31, which is at least as long as the casing 1, to an eyebolt in the cap 3. This cap 3 also carries an electricallyignited propelling charge 32, as described in the parent Specification. In operation, when the device is actuated by ignition of the charge 32, the pressure exerted on cap 17 forces cap 2 off the casing 1 and expels the rigidly connected casings 5 and 7. After these have travelled the length of cable 31 and are therefore clear of casing 1, the pull on the tautened cable on loop 30 pulls away the seal 22 so as to draw the matches 28, 29 through, the igniter compositions in chambers 23, 24 thereby causing them to ignite the delay fuzes 25, 26 and in due course the booster composition 27, the ignition of which blows off the block 18 and cap 17 and ignites the flare signal. The pins securing the locking ring 12 are thereby withdrawn so that the casings 5 and 7 separate and the heavy flare pulls the main parachute out of its casing. When an auxiliary parachute is used, it is immediately freed on expulsion of the casings 5 and 7, and operates to slow down the rate of travel of the combined casings for a period dependent on the delay arranged in the construction of the fuze block after which the separation of the casings permits the auxiliary parachute to pull the casing 7 off the main parachute, and support it during its descent to earth. According to a modification, a delay fuze is ignited directly by the charge 32, the arrangement being such that the continuity of the fuze channel is normally broken but is capable of being restored after the flare-parachute unit is expelled from the container 1.