Laydown unstacker

Claim 1

FOR USE IN A MATERIALS HANDLING SYSTEM, THE COMBINATION COMPRISING: CONVEYOR MEANS CONTINUOUSLY OPERABLE IN A STRAIGHT LINE PATH THROUGH AN UNSTACKING STATION; CARRIER FRAME MEANS LOCATED AT SAID STATION AND MOUNTED TO BE SWUNG IN A VERTICAL ARC BETWEEN A SUBSTANTIALLY VERTICAL POSITION WHERE IT CAN RECEIVE A STACK OF CASES BEING TRANSPORTED BY SAID CONVEYOR MEANS AND A SUBSTANTIALLY HORIZONTAL POSITION WHERE IT CAN RELEASE THE RECEIVED CASES INDIVIDUALLY TO SAID CONVEYOR MEANS, SAID CARRIED FRAME MEANS INCLUDING A PLURALITY OF RIGIDLY INTERCONNECTED ELEMENTS; SELECTIVELY OPERABLE STACK-RETENTION MEANS ON SAID CARRIER FRAME MEANS FOR RECEIVING AND HOLDING A STACK OF CASES IN ASSEMBLED RELATIONSHIP DURING SWINGING OF SAID FRAME MEANS FROM SAID VERTICAL POSITION TO SAID HORIZONTAL POSITION AND FOR RELEASING SAID CASES THEREAFTER, INCLUDING A PAIR OF ARMS ROTATABLY MOUNTED ON SAID RIGIDLY INTERCONNECTED ELEMENTS TO BE PIVOTED ABOUT RESPECTIVE AXES PARALLEL WITH THE LONGITUDINALLY AXIS OF SAID CARRIER FRAME MEANS, SAID ARMS BEING PIVOTALLY CONVERGIBLE TO INWARD POSITIONS OBSTRUCTING PASSAGE OF CASES AND BEING PIVOTALLY RETRACTABLE TO LATERAL POSITIONS FREE TO SAID CASES WHEREBY TO PERMIT SWINGING OF SAID FRAME MEANS BACK TO ITS VERTICAL POSITION BEFORE THE FINAL CASE OF A LAID DOWN STACK HAS BEEN CLEARED FROM THE DOWNSTREAM END OF SAID FRAME MEANS BY SAID CONVEYOR MEANS; FLUID-ACTUATED JACK MEANS MOUNTED ON SAID CARRIER FRAME MEANS AND CONNECTED TO SAID ARMS FOR ROTATING SAID ARMS; AND CONTROL MEANS FOR SAID JACK MEANS, INCLUDING FIRST POSITION RESPONSIVE SWITCH MEANS DISPOSED TO BE ACTUATED BY THE SITUATION OF SAID FRAME MEANS IN ITS SUBSTANTIALLY HORIZONTAL POSITION AND SECOND POSITION RESPONSIVE SWITCH MEANS DISPOSED TO BE ACTUATED BY THE RETURN OF SAID FRAME MEANS TO ITS VERTICAL POSITION, SAID FIRST AND SECOND SWITCH MEANS BEING CONNECTED IN FLUID CIRCUIT WITH SAID JACK MEANS FOR OPERATING SAID JACK MEANS.