GB642680A - Power actuated crane - Google Patents

Abstract

642,680. Load-handling apparatus; jib cranes. LETOURNEAU, Inc., R. G. Aug. 27, 1947, No. 23733. Convention date, Sept. 3, 1946. [Classes 78 (iii) and 78 (iv)] [Also in Group XXXI] In a portable load-handling device of the kind comprising a body, an upstanding elevator frame tiltably mounted on the body and a carriage, bearing a load-supporting member, movable up and down the elevator frame, the tilt of the frame is controlled by a beam which is pivotally connected to the frame and movable longitudinally to effect such control by a power-actuated cable system. The body 1, Fig. 1, connected by a steering and coupling unit 2 to a two-wheeled tractor 3, is fixed to a shaft 4 supported by wheels 6 and on this shaft a frame 12 is supported by bearings 13. Movable on the frame is a carriage 15 fitted with a loadsupporting fork 16 or a jib 17 having a hoist cable unit 18 operated by a winch 19. The inclination of the frame is adjusted by a beam 20 which is pivoted to the frame at 21 and extends between the sheaves 23, 24, Fig. 4, of a sheave block 22 mounted on a support 27, so as to be supported by a rail 26 engaging in a groove of a roller 25 mounted between the sheaves 24 of the block. Adjustment of the beam is effected by cables 32, 33, Figs. 1, 5, which are connected at one end at 36 to the sheave block 22 and pass respectively round sheaves 30, 31 and also the sheaves 23, 24 to be wound in opposed relation on a drum 37 of a reversible winch 38. The wheels 6 may be steered through an electric actuator 10, Fig. 2, which extends or contracts a telescopic rod 9 connected to knuckle-arms 7 of steering spindle units 5. The actuator, together with the winches 19, 38 are included in an electric circuit which includes control switches accessible to the driver of the tractor 3.