Patent GB-948100-A (GB)
Title: Improvements in or relating to a delayed-release locking device
Inventor: COOPER DANIEL WAUMSLEY
IPC: B64D1/02
Filed: 1961-05-04
Abstract: 948,100. Time-delayed fastenings. G. Q. PARACHUTE CO. Ltd. April 27, 1962 [May 4, 1961], No. 16248/61. Heading E2A. A delayed release locking device comprises means at one end for attaching a load, means at the other end for attaching a supporting means for the load, locking means for holding an attachment, and a timing mechanism which is held immobilised until a predetermined strain developed between the two ends of the device trips the timing mechanism which after a delay has expired, releases the locking means to release the attachment. As shown, the device comprises a first housing 1 mounted for axial movement within a second housing 7. The first housing includes a part 2 carrying a swivel eye 3, a part 4 and an annular toothed union 5 securing the parts 2 and 4 together. The union 5 consists of a ring having a plurality of lugs 6 projecting coaxially therefrom. The housing 7 is formed by an annular sleeve 8 and a head 9 in which are pivoted, on a shaft 9, a pair of spring-loaded detent lugs 12, 13. The sleeve 8 is provided with apertures 18 complementary to the lugs 6. A rigging line ring 19 is secured in position on the head 9 by portions 20 of a sleeve 21 which is screwed on to the head. The lugs 12, 13 each extend through a square hole in a cap 24 closing a timing mechanism compartment, each lug being provided with a cut-away portion 25, which together constitute a square hole into which a square spigot 26 can be caused to extend. The spigot 26 is carried by a threaded shaft 28 which is driven from a spring loaded clockwork mechanism. A spring-loaded U- shaped element 39 extends through the cap 24 and a plate 38, the cross piece of the element 39 carrying an arm 44 which is engageable with one of four projections 45 provided on a gearwheel 36 of the mechanism. The swivel eye 3 includes a ball race 49 and an externally screwed and flanged tubular member 50. A key 52 extends through the member 50, the key having two parallel limbs 53, a guide slot 54 for a screw 55 and a screwed outer end 56, which is engaged by a nut 59. A nut 57 is engaged on the member 50 and the nut 57, swivel 3 and member 50 are locked together by a screw 58. A pin 60 extends through the member 50. In operation, for releasing loop tapes 64 of a drogue sock 63 which encloses a stabilizer parachute 62 the drag exerted on a person to which the device is attached causes movement between the housings 1 and 7 to depress the element 39 and thus free the gearwheel 36 to allow the clockwork mechanism to unwind, the spigot 26 to withdraw from the lugs 12, 13, which then move radially inwardly to disengage the cap 24 and free the housings 1 and 7 for relative axial movement so that the lugs 6 become clear of the tops of the apertures 18 whereby to free the tapes 64 and permit operation of the parachute 62. The device is reset to the condition shown in Fig. 1 by attaching the parachute and drogue sock, rotating screw 55 to withdraw its free end from the key 52, rotating the nut 59 to move the key 52 towards the clockwork mechanism until limbs 53 of the key are disposed on each side of a pin 48 and the pin 60. The mechanism can then be rewound by rotating the swivel eye 3 and nut 57 and moving the mechanism axially to depress the element 39. Continued rotation of the eye 3 rotates nut 29 to re-engage the spigot 26 with the lugs 12, 13 and the key is retracted by rotating nut 59.