GB874279A - Improvements relating to the loading of aircraft - Google Patents

Abstract

874,279. Lift trucks for transferring freight containers to and from aircraft. M.L. AVIATION CO. Ltd. May 26, 1960 [Feb. 26, 1959], No. 6762/59. Classes 78 (3) and 78 (4). [Also in Group XXV] The base member 10 of the parallelogram lifting linkage 8, 9, 10 of a lift truck is automatically maintained at a fixed distance from the loading door 14 of an aircraft by arms 11 which engage recesses 13 in the fuselage and which are supported by an hydraulic positioning ram 15, 16. In operation, wheeled pallets 4 are rolled along guides 6 on a trailer 5 on to rail section 7 supported by the lifting platform 8 which is then raised to the loading opening, by means of an hydraulically operated ram 22, whereafter hydraulically operated lazy tongs 25 move the rail section 7 with the pallet 4 on to rollers 28 in the aircraft to a position in which the pallet abuts a stop 29. In this position, a loading catch (not shown) on the underside of the pallet is engaged by a pawl 34 of a driving member 35 movable along a central guide 31 by an endless wire rope 36 passing around an air motor driven pulley 38. The pallet is thus driven along guides 30, 32 to its storage position 40 at the end of the guides where it abuts a buffer which, through a system of linkages, operates a claw (see Group XXV) to hold the pallet in position and also causes the loading catch to be retracted by the pawl 34 so that the driving member 35 can continue to the end of the guides where it operates a valve 56, in a pneumatic system (Fig. 4, not shown), which changes the direction of rotation of the air motor to return the driving member 35 along its path. When the driving member reaches the limit of its forward travel it operates a valve 57 which again changes the direction of the air motor so that the pawl 34 engages in the loading catch of the next pallet elevated by rail section 7. The claw to hold the pallet in its storage position is actuated when this second pallet abuts the first. The driving member will only move from its forward position if a pallet and the rail section 7 are moved into the opening 14 to actuate valves 58 and 59. To unload the aircraft, a selector valve in the pneumatic circuit is actuated to move the driving member 35 to the rear end of the guide 31 and to retract pawl 34 and raise pawl 61. A thrustor 127 is actuated to withdraw the claw holding the most forward pallet and on the return movement of the driving member 35 pawl 61 engages in an unloading catch (not shown) on this pallet. The unloading catch is operated in a similar manner to the loading catch described above. The claws holding the succeeding pallets are retracted successively by actuation of the thrustors 137, 142, 152. The pallets in their storage position are held steady by means of the claws, guides 30, 32 and further rollers engaging slots 32a in the side of guides 30, 32.