Boom attachment for lift truck

Claim 1

IN A BOOM ATTACHMENT FOR USE WITH A LIFT TRUCK INCLUDING: (A) A FORWARDLY AND REARWARDLY TILTING MAST STRUCTURE, (B) A VERTICALLY MOVABLE CARRIAGE IN ASSOCATION WITH SAID MAST STRUCTURE, (C) FORK ARMS PROJECTING FORWARDLY FROM SAID CARRIAGE, (D) SAID ATTACHMENT COMPRISING: (E) A BOOM STRUCTURE, INCLUDING A TRANSVERSELY EXTENDING TRUNNION MEMBER AT THE BASE OF SAID BOOM STRUCTURE ADAPTED TO BE ROTATABLY SUPPORTED TRANSVERSELY ON SAID FORK ARMS AND POSITIONED AT THE INTERSECTION BETWEEN THE INNER ENDS OF SAID FORK ARMS AND AN UPRIGHT PORTION OF SAID CARRIAGE, (F) SAID TRUNNION MEMBER INCLUDING MEANS FOR CENTERING SAID BOOM STRUCTURE WITH RESPECT TO SAID FORK ARMS, (G) A POST STRUCTURE CENTRALLY MOUNTED ON SAID TRUNNION MEMBERR FOR ROTATION RELATIVE TO SAID BOOM STRUCTURE, (H) DOWNWARDLY OPENING HOOK MEANS ON SAID POST STRUCTURE FOR SECURING SAID POST STRUCTURE IN AN UPRIGHT POSITION ON SAID CARRIAGE AND FOR AT LEAST PARTIALLY SUPPORTING SAID ATTACHMENT ON SAID CARRIAGE, (I) SAID BOOM STRUCTURE BEING ROTATABLE FROM A FIRST, INOPERATIVE POSITION IN JUXTAPOSITION WITH SAID POST STRUCTURE TO A SECOND, LOAD LIFTING POSITION AT A PREDETERMINED ANGLE WITH RESPECT TO SAID POST STRUCTURE, (J) MEANS CONNECTING SAID BOOM AND POST STRUCTURE FOR MAINTAINING SAID BOOM STRUCTURE IN SAID LOAD LIFTING POSITION, (K) AND COOPERATIVE MEANS ON SAID POST STRUCTURE AND SAID BOOM STRUCTURE FOR SELECTIVELY MAINTAINING SAID BOOM STRUCTURE IN SAID INOPERATIVE POSITION.