Boom leveling and compensating means

Claim 1

IN A SHIPLOADING APPARATUS HAVING A SUPPORTING FRAME, AN UPWARDLY EXTENDING MAST CARRIED BY SAID FRAME, AN ELEVATED TRACKWAY HORIZONTALLY DISPOSED IN SAID FRAME, A BOOM SHUTTLE CAR MOVABLE BACK AND FORTH ALONG SAID TRACKWAY, MEANS FOR MOVING SAID SHUTTLE CAR ALONG SAID TRACKWAY, AND A LATERALLY EXTENDING ELONGATED BOOM, INCLUDING BULK MATERIAL CONVEYING MEANS, PIVOTALLY SECURED AT ONE EXTREMITY OF SAID BOOM TO SAID SHUTTLE CAR, THE IMPROVEMENT WHICH COMPRISES IN COMBINATION: (A) BOOM PULLEY MEANS SECURED TO THE BOOM INTERMEDIATE ITS EXTREMITIES; (B) MAST CROWN DULLEY MEANS SECURED TO THE UPPER EXTREMITY OF SAID MAST; (C) PULLEY MEANS SECURED TO THE SHIPLOADER FRAME ADJACENT THE OUTER EXTREMITY OF SAID TRACKWAY; (D) COMPENSATING MOVABLE PULLEY BLOCK MEANS ADAPTED TO MOVE ALONG A PATH BETWEEN SAID MAST CROWN PULLEY MEANS AND SAID SHIPLOADER FRAME PULLEY MEANS; (E) A CABLE REEVED THROUGH ALL SAID PULLEY MEANS; (F) ROTATABLE DRUM MEANS HAVING ONE END OF SAID CABLE SECURED THEREIN; (G) SAID CABLE BEING REEVED SUCCESSIVELY FROM SAID DRUM MEANS THROUGH SAID MAST CROWN PULLEY MEANS, THE BOOM PULLEY MEANS AND THE MOVABLE PULLEY MEANS, AND MEANS FOR SECURING THE FREE END OF SAID CABLE; AND (H) A SEPARATE CABLE COACTING BETWEEN SAID MOVABLE PULLEY BLOCK AND SAID SHIPLOADER FRAME PULLEY IN RESPONSE TO THE POSITION OF SAID SHUTTLE CAR TO REGULATE THE AMOUNT OF CABLE EXTENDING BETWEEN SAID MAST CROWN PULLEY MEANS AND THE BOOM PULLEY MEANS WHILE SAID DRUM MEANS ARE STATIONARY, TO MAINTAIN THE FREE END OF THE BOOM SUBSTANTIALLY LEVEL AS THE SHUTTLE MOVES ALONG SAID TRACKWAY.