Patent GB-1051482-A (GB)
IPC: B66C1/34
Abstract: 1,051,482. Cargo hook. BOEING CO. March 11, 1964 [March 11, 1963], No. 10281/64. Heading F2H.  A cargo hook comprises a housing means for engaging and grasping a load mounting means rotatably mounting the engagement means on said housing means mounted on the housing for selectively locking the engagement means in a locked position, means for releasing said engagement means for rotation, return means mounted on the mounting means 4 connected to said engagement means being provided for returning said engagement means to its pre-release position. The housing 11 comprises two side plates 30, 31 connected together at their upper extremities, a swing assembly 32 being rotatably mounted on the shaft 35 which is supported between the lower extremities of the plates. The swing assembly is damped so that it is limited to one rotation about the shaft 35. The spiked hook 33 has an integral cylindrical base 34 which is mounted for limited rotational movement in a cylindrical bore in the swing assembly 32, the base 34 being restrained from rotation by a torsion spring 43. The hook has a cable grasping surface 67 which is off-set from the longitudinal axis of the base 34 so that the hook can rotate about its base 34 to maintain a position perpendicular to the resisting force of a remote load. The return means, Fig. 4, is disposed about the shaft 35 and comprises a helical cam 123 axially movable therealong but non-rotatable and held in engagement with a roller 124 mounted on the swing assembly 32, by spring means. The hook assembly is mounted on the extremity of a cable 10 by a fitting 15 to which the housing 11 is pivotally attached by a torsion spring assembly which includes tongue and groove hinges 12, 16, 16<SP>1</SP>; 13, 17, 17<SP>1</SP>.The torsion springs 25, 28 urge the cable fitting 15 into a canted position with respect to the housing 11 during periods of no load. Means mounted on the housing for selectively locking the hook comprise a push rod 91 connected to a pivoted cam 93 mounted on a pin 96 and biased in an upward position by a spring 97, there being also provided a bell crank lever 100 hinged at 102 and provided on one pair of arms with a cam follower 101 which engages in a slot 95 in the cam 93. The other pair of arms of the bell crank have mounted therebetween a roller 103 which normally abuts the swing assembly 32. The load is released by a messenger 90 released from the towing vehicle and caused to slide down the cable 10 to strike the push rod 91 so that the cam 95 pivots and drives the roller 103 to a position in which it does not obstruct the swing assembly 32. The cable to be grasped slides down the tow cable 10 and strikes a blunt arcuate surface which adjoins the slant surface 81 of a cap 80 which fits over the cable fitting 15; thereby inducing a turning moment in the hook so that the cable is allowed to slide down the slanting surface 81 over cam guides 82, 83 mounted on the fitting 15 and into the hook spike 33. Contact of the cam guides 82, 83 with the cable to be grasped causes rotational orientation of the hook due to the centre of gravity of the hook being off-set with respect to the centre line of the tow rope.