Patent GB-883103-A (GB)
Title: Improvements relating to apparatus for towing aerial targets
Inventor: LOBELLE MARCEL JULES ODILON
IPC: B64F1/08
Filed: 1959-07-13
Abstract: 883,103. Towing and releasing targets from aircraft. M. L. AVIATION CO. Ltd. July 1, 1960 [July 13, 1959], No. 24060/59. Class 4. Apparatus for replacing, in flight, a target towed at the end of a cable behind an aircraft, comprises a carriage unit to which a further target can be attached, and which is movable along the cable, a clamping device on the unit for locking it to the cable, and a device for cutting the cable to release the first target, operation of both the cutting and clamping devices being initiated by movement of the unit to the end of the cable, so that the first target is jettisoned, the unit locked to the cable, and the further target towed. In the Fig. 1, the carriage unit comprises two carriages 1, 2, initially slidably mounted, on a T-section rail 3 beneath the aircraft. The first target is secured by a lanyard 7 and shackle 8 to a unit 6 to which cable the 5 is secured at 11. Levers 9, 10, pivoted to unit 6 bear an anvil 12 and cutting edge 13, and form a toggle linkage with levers 14, 15. The cable passes through guide 16 and tube 17 on carriage 1, and guide 19 on carriage 2. Carriage 1, and thus carriage 2, are retained on rail 3 by a hook 20 pivoted to the rail and held in engagement with a recess 21 in carriage 1 by a spring 22. The cover 26 of the further target is attached to an S-shaped member 27 pivoted to carriage 1, by a line 25 which passes through a loop 24 of shear-wire on hook 20. The two carriages are attached by a rope 29 extending from member 27 and initially wound on a drum 30 on carriage 2. Member 27 is prevented from rotating and releasing rope 29 by an arm 31 on the member engaging a lever 32 pivoted at 33, the cable 5 passing between the lever and a block 36. The target is connected to carriage 1 by a line 37. A further line 39, longer than line 29, connects the two carriages, being initially wound on a drum 38 on carriage 1, and connected by a bridle 40, 41, to two jaws 42, 43 pivoted to carriage 2, and adapted to clamp the cable when the bridle is under tension. A brake on carriage 2 comprises two blocks 46, 47 adapted to grip the cable, the former being fixed and the latter being urged towards block 46 by a pin 50 on a lever 48 pivoted to the carriage at 49 and acted only by a spring 51 adjustable by a set screw 54. The brake is initially held off by a projection 53 on rail 3 engaging a roller 52 on lever 48. The carriage 2 also has a cable cutting toggle linkage 55, 56, 57, 58 similar to the linkage 9, 10, 14, 15, or unit 6. To replace the target, the new target in its cover is thrown from the aircraft. When line 25 becomes taut, it swings hook 20 to the position shown in broken lines, where it is retained by spring 22. The wire 22 then shears, and the drag on the target pack pulls carriages 1 and 2 along the cable. The brake 46, 47 is applied when roller 52 leaves projection 53, to limit the speed of carriage 2 along the cable. Line 29 is payed out from drum 30 to its fullest extent as carriage 1 proceeds, and the two carriages then travel together, line 29 being taut. Impact of carriage 1 on the toggle linkage 9, 10, 14, 15, cuts the cable, and the first target falls away. The carriage 1 then moves off the end of the cable, as it does if the unit 6 has been shot away during practice firing. Spring 34 then rotates lever 32 to abut block 36, releasing arm 31 and member 27, from which lines 25 and 29 are released. Line 39 then becomes taut, and the bridle 40, 41 rotates jaws 42, 43, to clamp on the cable and arrest carriage 2. Line 37 also becomes taut, and pulls the target out of its cover. This target can in turn be replaced by sending a further target on a similar carriage unit along the cable. The cutting devices may be on the leading edges of the carriage units. Specification 789,169 is referred to.