Lifting hook assembly

Claim 1

A LIFTING HOOK ASSEMBLY FOR USE ON CASTING FORMS WHOSE WIDTHS LIE WITHIN A SUBSTANTIAL RANGE, SAID ASSEMBLY COMPRISING A SUPPORTING BEAM, A PAIR OF OPPOSED HOOKS, EACH HOOK HAVING A BASE PORTION AND AN ELONGATED CURVED BODY PORTION TERMINATING IN A CLAW, MEANS SUPPORTED BY SAID BEAM FOR PIVOTALLY SUPPORTING SAID HOOKS AT THE BASES THEREOF FOR PERMITTING MOVEMENT OF SAID HOOKS SO THAT THE DISTANCE BETWEEN OPPOSED CLAWS CAN BE VARIED, A PAIR OF LINKS PIVOTALLY SECURED TO SAID HOOKS AT REGIONS SPACED FROM THE HOOK PIVOTS, SAID LINKS EXTENDING GENERALLY TOWARD EACH OTHER AND HAVING THEIR ENDS PIVOTALLY SECURED TO PROVIDE A TOGGLE JOINT, POWER MEANS INCLUDING A ROD COUPLED TO SAID LINKS FOR OPERATING SAID TOGGLE JOINT TO CONTROL THE HOOK POSITIONS, SAID ROD BEING MOVABLE OVER A RANGE ALONG A LINE WHICH IS SUBSTANTIALLY NORMAL TO A LINE EXTENDING BETWEEN THE CENTERS OF THE LINK PIVOTS TO PROVIDE NORMAL TOGGLE JOINT ACTION, MEANS FOR LIMITING THE RELATIVE TURNING MOVEMENT OF A TOGGLE LINK AND HOOK BASE PORTION WHEREBY SAID TOGGLE JOINT CAN BREAK FROM ONE END POSITION WHERE SAID TOGGLE LINKS ARE ALONG A SUBSTANTIALLY STRAIGHT LINE TO ANOTHER POSITION WHERE THE KNEE OF THE TOGGLE JOINT IS BENT TO PROVIDE A CERTAIN ANGLE, SAID RANGE OF ROD MOVEMENT BEING SUBSTANTIALLY GREATER THAN IS REQUIRED FOR OPERATING SAID TOGGLE JOINT OVER ITS RANGE, SAID PIVOTAL HOOK SUPPORTING MEANS INCLUDING MEANS FOR PERMITTING SAID HOOKS TO MOVE LINEARLY INDEPENDENTLY OF PIVOTAL MOTION OF HOOKS ABOUT THE HOOK PIVOTS, SAID LINEAR MOVEMENT OF SAID HOOKS BEING IN A DIRECTION GENERALLY PARALLEL TO SAID ROD MOVEMENT WHEREBY ROD MOVEMENT TENDING TO TURN SAID TOGGLE JOINT LENGTHS BEYOND THE TOGGLE LIMITS RESULTS IN MOVEMENT OF SAID HOOKS LINEARLY.