Self powered boom assembly

Claim 1

A HOISTING ASSEMBLY COMPRISING IN COMBINATION, A MAST CONNECTABLE FIXEDLY AT THE NORMALLY LOWER END THEREOF TO A SUBSTANTIALLY HORIZONTAL SUPPORTING SURFACE SO AS TO EXTEND SUBSTANTIALLY VERTICALLY UPWARD THEREFROM IN USE FOR SUPPORT THEREBY, A HEAD HAVING A SOCKET RECEIVING THE UPPER PORTION OF SAID MAST AND SUPPORTED SOLELY BY SAID UPPER PORTION OF SAID MAST FOR ROTATION ABOUT THE AXIS THEREOF, A BOOM EXTENDING SUBSTANTIALLY HORIZONTALLY THROUGH THE UPPER PORTION OF SAID HEAD AND LONGITUDINALLY MOVABLE RELATIVE TO SAID HEAD IN OPPOSITE DIRECTIONS, FLEXIBLE HOISTING MEANS OPERABLY SUPPORTED BY SAID BOOM AND EXTENDING FROM ONE END THEREOF TO RAISE AND LOWER LOAD MEANS, SELF-ENERGIZING POWER GENERATING MEANS SUPPORTED ENTIRELY BY SAID HEAD AND NOT EXTENDING APPRECIABLY ABOVE THE UPPER SURFACE OF SAID BOOM, AND POWER TRANSMITTING MEANS BETWEEN SAID POWER GENERATING MEANS AND SAID HEAD AND OPERABLE TO ROTATE SAID HEAD RELATIVE TO THE UPPER END OF SAID MAST AND ABOUT THE AXIS THEREOF.