Crane mechanism

Claim 1

A STACKER CRANE COMPRISING, A TROLLEY MOVABLE ALONG ONE PATH, COLUMN MEANS EXTENDING FROM THE TROLLEY, A CARRIAGE MOVABLY MOUNTED ON SAID COLUMN MEANS FOR MOVEMENT LENGTHWISE THEREOF WHEREBY THE CARRIAGE MAY MOVE ALONG TWO AXES, LOAD SUPPORTING LIFT MECHANISM ON SAID CARRIAGE SELECTIVELY EXTENDABLE TO EITHER SIDE OF SAID CARRIAGE ALONG A PATH NORMAL TO THE COLUMN MEANS FOR ACCESS TO STORAGE AREAS AT EITHER SIDE OF THE CARRIAGE, A PLURALITY OF MOTORS ONE FOR EACH OF SAID TROLLEY, CARRIAGE AND LIFT MECHANISM FOR PROVIDING POWERED MOVEMENT THEREOF, A FIRST SET OF CAMS ON SAID COLUMN MEANS IN POSITIONS RELATED TO THE VERTICAL RELATION OF THE SPACED STORAGE AREAS, SWITCH MEANS ON SAID CARRIAGE ACTUABLE BY SUCCESSIVE ONES OF SAID CAMS IN ACCORDANCE WITH THE VERTICAL RELATION OF THE CARRIAGE TO THE STORAGE AREAS, A SECOND SET OF CAMS ON SAID COLUMN MEANS IN POSITIONS RELATED TO THE VERTICAL RELATION OF THE SPACED STORAGE AREAS AND POSITIONED SLIGHTLY ABOVE A CORRESPONDING ONE OF SAID FIRST SET OF CAMS, SECOND SWITCH MEANS ON THE CARRIAGE ENGAGEABLE WITH ONE OF SAID SECOND SET OF CAMS WHEN THE CARRIAGE IS AT AN ELEVATION TO LIFT A LOAD FROM THE STORAGE AREA, AND A THIRD SET OF CAMS ON SAID COLUMN MEANS IN POSITIONS RELATED TO THE VERTICAL RELATION OF THE SPACED STORAGE AREAS AND POSITIONED SLIGHTLY BELOW A CORRESPONDING ONE OF SAID FIRST SET OF CAMS, AND THIRD SWITCH MEANS ON SAID CARRIAGE ENGAGEABLE WITH ONE OF SAID THIRD CAMS WHEN THE CARRIAGE IS AT A DEPRESSED LEVEL TO LOWER A LOAD IN THE STORAGE AREA.