Portable lift

Claim 1

A PORTABLE LIFT ADAPTED TO AID IN LOAD TRUCKS, DOCKS AND THE LIKE AND COMPRISING IN COMBINATION A FRAME HAVING A BASE ARRANGED TO BE SUPPORTED UPON THE GROUND OR THE LIKE AND PROVIDED WITH VERTICAL GUIDE MEANS SUPPORTED THEREBY, A NORMALLY HORIZONTAL LOAD-CARRING PLATFORM CARRIED BY SAID FRAME FOR GUIDE MOVEMENT VERTICALLY TO DESIRED ELEVATIONS ABOVE SAID BASE THEREOF, POWER MEANS OPERABLE TO MOVE SAID PLATFORM AS AFORESAID, A PAIR OF WHEELS ROTATABLY CARRIED BY SAID BASE OF SAID FRAME RESPECTIVELY AT OPPOSITE SIDES, THEREOF INTERMEDIATELY OF THE ENDS OF SAID SIDES, AND POSITIONING MEANS MOVABLY SUPPORTED BY SAID BASE, SAID WHEELS BEING ROTATABLY SUPPORTED BY SAID POSITIONING MEANS AND SAID POSITIONING MEANS BEING ACTUATED BY LIMITED MOVEMENT OF SAID PLATFORM RELATIVE TO SAID BASE TO EFFECT MOVEMENT OF SAID WHEELS VERTICAL TO AND FROM SUPPORTING POSITIONS IN WHICH THE PERPHERIES OF WHEELS ARE BELOW THE BOTTOM SURFACE OF THE BASE OF SAID FRAME AND CONSITUTE THE SOLE MOBILE SUPPORTING MEANS FOR SAID FRAME AND PLATFORM THEREON, THEREBY RENDERING THE SAME PORTABLE FOR MOVEMENT ALONG A SUPPORTING SURFACE TO POSITION THE PORTABLE ELEVATOR WHERE DESIRED, SUCH ARRANGEMENT OF WHEEL MEANS RELATIVE TO SAID BASE OF SAID FRAME PERMITTING THE TURNING OF SAID FRAME WITHIN THE LIMITS OF ITS OWN LENGTH INCIDENT TO POSITIONING THE LIFT AS DESIRED AND ALSO LEAVING THE OPPOSITE END OF SAID FRAME AND PLATFORM FREELY ACCESSIBLE FOR LOADING AND UNLOADING EITHER WHEN THE PLATFORM IS IN ITS LOWERMOST POSITION OR ELEVATED, WHEREBY SAID WHEEL MEANS THEN MAY BE ELEVATED TO CAUSE THE BASE OF THE FRAME TO REST UPON A SUPPORTING SURFACE FOR FIRM SUPPORT THEREBY WHILE ELEVATING LOADS UPON SAID PLATFORM RELATIVE TO SAID FRAME.