Material handling device

Claim 1

A MOBILE CRANE COMPRISING AN ARTICULATED CHASSIS HAVING A FRONT SECTION CARRYING WHEELS MOUNTED FOR ROTATION ON A FIXED AXIS TRANSVERSELY OF THE FRONT SECTION, AND A REAR SECTION HAVING WHEELS MOUNTED FOR ROTATION ON A FIXED AXIS TRANSVERSELY OF THE SECOND SECTION, PIVOT MEANS CONNECTING SAID SECTIONS FOR RELATIVELY SWINGING MOVEMENT ABOUT A VERTICAL AXIS, MEANS ON SAID FRONT SECTION FOR SWINGING SAID REAR SECTION, A SERIES OF UPRIGHTS CARRIED ON SAID FRONT SECTION, AN UPPER CHASSIS FRAME CARRIED BY SAID UPRIGHTS AND OVERLYING SAID SECTIONS, A ROLLER CARRIED ON TOP OF SAID SECOND SECTION THE SUPPORT FOR SAID ROLLER BEING IN CLOSE VERTICAL ALIGNMENT WITH THE AXIS OF ROTATION OF THE WHEELS OF THE REAR SECTION AND ROTATABLE ON A HORIZONTAL AXIS ARRANGED LONGITUDINALLY OF SAID SECOND SECTION, A TRACK OF ARCUATE FROM CARRIED ON THE UNDERSIDE OF SAID UPPER FRAME, AND DWELLING ON SAID ROLL, DRIVE MEANS CARRIED BY SAID UPPER FRAME AND CONNECTED TO THE WHEELS IN EACH OF SAID SECTIONS, A STANDARD MOUNTED ON SAID UPPER FRAME, AT THE FORWARD END THEREOF, A MAST OF TRUSS CONSTRUCTION AND TRIANGULAR IN CROSS SECTION, PIVOTED AT ITS BOTTOM AND ALONG ONE SIDE, TO SAID STANDRAD, ON A HORIZONTAL AXIS ARRANGED TRANSVERSELY OF SAID UPPER FRAME, SAID MAST BEING HINGED MEDIALLY OF ITS LENGTH ON AN AXIS ON SAID ONE SIDE, AND PARALLEL TO SAID HORIZONTAL AXIS, LATCH MEANS FOR KEEPING THE MAST SECTIONS ALIGNED WHEN UNFOLDED, POWERED THRUST MEANS CARRIED BY SAID UPPER FRAME AND PIVOTALLY ENGAGING SAID MAST ON A HORIZONTAL AXIS PARALLEL TO AND OFFSET REARWARDLY FROM THE AXIS OF PIVOTING OF SAID MAST, POSITIONABLE AT TWO DIFFERENT THRUST MEANS, SELECTIVELY POSITIONABLE AT TWO DIFFERENT HEIGHTS, PROP MEANS SWINGABLY MOUNTED ON SAID UPPER FRAME, AND ADAPTED TO HOLD SAID MAST IN ONE POSITION OF ERECTION, MEANS ANCHORING THE UPPER PART OF SAID MAST TO SAID UPPER FRAME, WHEREBY SAID MAST UNFOLDS IN REPONSE TO THE SWINGING MOVEMENT OF ERECTION, A PAIR OF POWER LIFT MEANS CARRIED BY SAID STANDARD, A FRAME SUPPORTED BY SAID LIFT MEANS AND PIVOTED IN A BALL-AND-SOCKET JOINT REARWARDLY OF SAID STANDARD, AND AN EARTH-WORKING BLADE CARRIED ON THE FRONT END OF SAID LATTER FRAME, SAID EARTH-WORKING BLADE, WHEN LOWERED IN CONTACT WITH THE EARTH, ACTING TO SUPPORT AND STABILIZE THE CRANE STRUCTURE DURING OPERATION OF THE CRANE.