Patent GB-538304-A (GB)
Title: Improvements in or relating to apparatus for transferring articles to and from aircraft in flight
IPC: B64D1/22
Filed: 1939-11-09
Abstract: 538,304. Transferring articles to and from aircraft in flight. ALL AMERICAN AVIATION, Inc. Nov. 9, 1939, No. 29754. Convention date, Nov. 12, 1938. [Class 103 (iii)] Relates to shock-absorbing means for the cable of apparatus for enabling an aircraft in flight to pick up and/or deliver loads. The apparatus comprises a pair of masts between which is extended and attached a rope to which the load to be picked up is also attached. The aircraft trails, by a cable, a grapple provided with arms adapted to engage and detach the rope with its load and the pull on the arms releases a second load attached to the grapple so that this load falls to the ground. The ground apparatus comprises a pair of masts 11 which converge upwardly and also forwardly in the direction of flight. The masts can be adjusted about vertical axes in sockets 12. A rope 26 to one or both ends of which a load 17 to be picked up is attached, is lightly attached as by string to arms 24 on a pair of heavy members 22 which are normally held to the top of the masts by cables 16 which pass from the members over pulleys 15 on the masts to winding drums 18. The members 22 can thus be lowered to near the ground as indicated for attaching the rope 26 and load 17 and can then be raised to the top of the masts. The weight of the load 17 is taken by a hook on the member 22. The apparatus on the aircraft comprises a grapple 30 having a number of arms 55 formed with notches 57 which may be integral with the arms or be provided by spring urged members 58 Fig. 8 and into which the rope 26 which is knotted at 27 can join. The arms 55 are formed on a tubular member 56 slidable on the main stem of the grapple and normally partially covering a recess 70 in the stem to secure the enlarged end 65 of a cord 37 by which the load 36 to be delivered is attached to the grapple. When the member 56 is moved downwards against the action of a spring 73 a pin 71 and inclined slot 72 cause it to turn so as to uncover the recess 70 and release the end of the cord. The cable 31 for suspending the grapple is attached to it by a buffer 52, 53 and to a winding drum 32 on the aircraft. When the device is ready for use the cable passes over a guide block 38 secured to a shock-absorber comprising a pair of parallel cylinders 42 mounted on the aircraft so as to be adjustable in inclination, by a bracket 43. The block 38 is secured to the ends of piston rods 41 slidable respectively in the cylinders 42 against the action of springs 44, the movement being damped in both directions by restricted passages for the air in the cylinders, provided in the sleeve 47 and at 49 in the cylinder wall. The passages 49 are adjustable by a screwed plug 48. The pull of the cable is transmitted to the shock-absorber by the engagement of an enlargement on the cable with a recess 39 in the block 38. In operation, the cable trailing from the aircraft engages the rope 26 and detaches it from the arms 24 and the cable runs through the bight which is thus formed in the rope, until the rope jams in the notches 57 of the grapple arms. The pull on these arms then slides the members 56 downwardly thus releasing the cord 37 and the load 36 which then falls to the ground. The apparatus may be used only for picking up or only for dropping a load.