Lifting beam

Claim 1

A LIFTING BEAM FOR ENGAGEMENT WITH A RECTANGULAR CONTAINER OF THE TYPE HAVING FOUR UPPER CORNERS AND AN UPWARDLY OPENING SOCKET MEMBER AT EACH OF SAID CORNERS THAT INCLUDES A BAR ADAPTED TO BE ENGAGED BY A HOOK ON SUCH BEAM FOR LIFTING AND CARRYING SAID CONTAINER, SAID BEAM COMPRISING: (A) A RECTANGULAR FRAME HAVING SPACED, PARALLEL SIDE FRAME MEMBERS IN SIDE BY SIDE RELATION AND (B) PARALLEL END FRAME MEMBERS CONNECTING CORRESPONDING ENDS OF SAID SIDE FRAME MEMBERS, (C) MEANS ON SAID BEAM FOR CONNECTING IT WITH A HOISTING MECHANISM, (D) FOUR HOOKS DEPENDING FROM THE LOWERMOST SIDE OF SAID FRAME, (E) PIVOTS RESPECTIVELY SUPPORTING SAID HOOKS ON SAID FRAME FOR ENTERING EACH OF SAID SOCKET MEMBERS UPON LOWERING SAID FRAME OVER SAID CONTAINER AND FOR SWINGING SAID HOOKS ABOUT HORIZONTAL AXES INTO ENGAGEMENT WITH SAID BARS WHEN SAID HOOKS ARE IN SAID SOCKET MEMBERS; (F) POWER ACTUATABLE MEANS CONNECTED WITH SAID HOOKS FOR SIMULTANEOUSLY SWINGING THEM ABOUT SAID HORIZONTAL AXES INTO AND OUT OF SAID ENGAGEMENT WITH SUCH BARS, (G) SAID HOOKS BEING MOVABLE VERTICALLY RELATIVE TO SAID HORIZONTAL AXES FROM PREDETERMINED LOWERED POSITIONS TO PREDETERMINED ELEVATED POSITIONS ABOVE SAID LOWERED POSITIONS AND VICE VERSA, (H) YIELDABLE MEANS CONNECTED WITH SAID HOOKS FOR YIELDABLY URGING THEM TO SAID ELEVATED POSITIONS AND FOR PERMITTING DOWNWARD MOVEMENT OF SAID HOOKS TO SAID LOWERED POSITIONS, AGAINST THE RESISTANCE OF SAID YIELDABLE MEANS, UNDER THE WEIGHT OF SUCH CONTAINER WHEN SAID BEAM IS LIFTED BY SUCH HOISTING MECHANISM, (I) MEANS RESPECTIVELY RIGID ON SAID FRAME AND ON SAID HOOKS IN POSITIONS FOR POSITIVELY OBSTRUCTING SWINGING OF SAID HOOKS ABOUT THEIR SAID AXES OUT OF LIFTING ENGAGEMENT WITH SAID BARS WHEN SAID HOOKS ARE IN SAID LOWERED POSITIONS IN LIFTING RELATION TO SAID BARS.