Patent GB-784053-A (GB)
Title: Improvements in releasable attachment devices for use in aircraft
Inventor: LOBELLE MARCEL JULES ODILON
IPC: B64D1/06
Filed: 1954-03-17
Abstract: 784,053. Releasing from aircraft. M. L. AVIATION CO., Ltd. March 17, 1955 [March 17, 1954], No. 7793/54. Class 9(2) A petrol tank 1 suspended beneath an aircraft wing 2 by a device 3 within a housing 5 may be released by means 4 containing an explosive. A lug 6, Fig. 2, screwed into the tank 1 is held by jaws 7, 8 pivoted on a support 11 fixed to the aircraft. Two parallel toggles 12, 13 connect the free ends of the jaws, each long link 12 having two parallel arms between which the short link 13 and a latch 14 can pivot, Fig. 3. The tendency of the weight of the tank to open the jaws is resisted by the latches 14, each latch being held between a movable wedge 15 carried by a movable part of the release means 4 and one of two parallel release levers 16, Fig. 3, so that the tank may be released by operating the means 4 or by movement of the levers 16. Springs 17 attached to the links 12 urge the latches 14 into engagement with the levers 16. The release means 4 carrying the support 11 is held in a crutch 19 which can swing about a pivot 20 passing through the housing 5. The means 4 comprises a cartridge chamber 21 connected to firing means 22 and to a cylinder 23 within which a slidable sleeve 24 is locked by balls 33. Within the sleeve is a piston 25 having at its lower end the wedge 15. A chamfered recess 26 in the piston coincides with a recess in the sleeve to house a spring clip 29, which holds the piston in position. On firing a cartridge in the chamber 21, the pressure on the piston causes the clip 29 to be pushed into the recess 28. The piston, thus freed, moves downwardly until the balls 33 engage a recess 36 near the top of the piston and lock the piston to the sleeve. The piston and sleeve then move together and are ejected from the cylinder 23. The wedge 15 has a screw-threaded boss 41 to fit a recess 42 in the lug 6. the boss being copositioned relative to the lug that the jaws 7, 8 open before the boss moves into the recess 42. An adapter may be screwed on to the boss 41, when a different form of lug is used. The threading also allows the application of a tool to withdraw the piston from the sleeve. The clutch 19 comprises a housing 43. containing a hollow worm 44 meshing with a worm wheel 45 having screw-threaded engagement on the cylinder 23, Fig. 2, so that by rotating the worm, the attachment device may be lowered for connection to the load and then raised until the load presses against the housing 5. To rotate the worm a member 46. splined to the worm, is adapted to be pushed back by an inserted tool and so disengaged from a member fixed to the housing 43. After removing the tool, a spring causes the members to re-engage. A link 51, which engages the release levers 16, is housed in a casing 52, Fig. 6 and controlled by a system of toggles. Parallel toggles 53, between which the link 51 is pivoted, are connected to the casing 52 and the common pivot of the toggle arms is an end pivot of a second toggle 54 also pivoted on the casing 52. A bell-crank lever 55 pivoted on the casing is connected by parallel links 56 to the common pivot of the toggle 54 and has a nose 57 held against a rod 58 of semi-circular section by a spring 59. Thus by rotating a lever 60, manually or by electrical means 61, the rod 58 is. turned to move the crank 55 and break the toggles, thereby releasing the levers 16, Whereupon the jaws 7, 8 open and the tank is droppd. When the lever 60 turns a contact 62 is. broken and may thus operate a warning circuit. The toggle and lever mechanism may be reset by means of a plunger 65 normally held by a spring 66. Specification 784,054 is referred to..