Patent GB-667202-A (GB)
Title: Improvements relating to apparatus for towing targets and the like
IPC: B64D3/02
Filed: 1949-06-13
Abstract: 667,202. Towing and releasing targets from aircraft. M. L. AVIATION CO Ltd., and LOBELLE, M. J, O. June 12, 1950 [June 13, 19491, No. 15718/49. Class 4. A target towing apparatus comprises a hollow buffer through which the towing cable passes and upon which holding devices such as rings for the targets may be mounted, an exchanger unit secured to the end of the towing cable and having pawls for retaining the holding device of a target and means within the exchanger unit for withdrawing one pawl or set of pawls upon engagement between the buffer and the exchanger unit, to effect the release of one holding device for a target and for simultaneously extending a second pawl or set of pawls to receive the holding device for a new target. As shown in Fig. 1 an exchange unit 27 is attached to a towing cable 18 which passes through a buffer 20, an emergency cable cutter and a fairlead 19 to a winch 15 driven by a variable pitch windmill 17. The buffer 20 comprises a coil spring 21 attached at one end to the aircraft 16 and at the other end carrying a hollow spigot 23. Targets 30, which are stowed in the cabin 29 until required, are connected by wires 24<SP>1</SP>, 25<SP>1</SP> passing through a launching chute 28 to anchor rings 24. 25 carried on the spigot 23. To replace a target the unit 27 is winched in until it co-operates with the buffer 20 and the used target anchor ring is released from the unit. A new target is then launched, breaking thin copper wires. Fig. 9 (not shown), which secured its anchor ring to the spigot 23 and drawing the ring onto the unit 27 where it is retained by a pair of pawls. The exchanger unit comprises two telescopic sections 32, 42, Figs. 10 and 11., urged apart by a spring 45 but held together when fully extended by a bolt 54. A pair of rear pawls 33 and a pair of front patrls 37 are pivoted to the section 32 at 34 and 38 respectively for movement in perpendicular planes. The pawls carry rollers 35, 39 which co-operate with a cam bar 36 attached to the end of the member 42. An anchor pin 41 mounted in the section 32 passes through slots 43 in the member 42 and a loop in the end of the towing cable 18. When the end 44 of the section 42 contacts the spigot 23 during the replacement of a target the sections 32, 42 telescope, the rollers 39 first moving out of a cam-bar depression 57 to project the front pawls after which the rollers 35 move into a cam-bar depression 56 to allow retraction of the rear pawls and the consequent release of the expended targets anchor ring 24. When the new target is released its anchor ring is retained by the front pawls 37 until the unit 27 extends as the winch begins to unwind the cable. During the extension the rear pawls are initially projected before the front pawls are retracted to allow the anchor ring of the new target to pass along the section 32 to its operative position. Before landing the target may be jettisoned simply by winding in the cable. A further embodiment is illustrated in Figs. 3-8 (not shown) wherein the targets are mounted externally of the aircraft and are provided with remotely operated detachable fastenings.