Apparatus for effecting the shifting of shelf or cabinet units for filing systems

Claim 1

FILING APPARATUS COMPRISING A PLURALITY OF FILING UNITS WHICH ARE SHIFTABLE ALONG TRACKS MOUNTED ON A FLOOR SO THAT A PASSAGEWAY CAN BE FORMED BETWEEN ADJACENT UNITS; AN ELECTRICALLY DRIVEN DRIVE DEVICE; AN ENDLESS FLEXIBLE DRIVE ELEMENT ARRANGED IN THE FORM OF AN ELONGATED LOOP AND CONNECTED TO SAID DRIVE DEVICE FOR BEING DRIVEN THEREBY, THE TWO OPPOSING LONGITUDINALLY EXTENDING REACHES OF THE LOOP BEING ARRANGED IN SUBSTANTIALLY EXTENDING REACHES OF THE LOOP BEING ARRANGED HAVING REGULARLY SPACED DRIVE MEMBERS MOUNTED THEREON; A PAIR OF ROTATABLE ELEMENTS MOUNTED ON EACH FILING UNIT FOR FREE ROTATAION WITH RESPECT THERETO, THE ROTATABLE ELEMENTS HAVING RADIAL PROJECTIONS IN CONSTANT POSITIVE ENGAGEMENT WITH THE DRIVE MEMBERS ON THE RESPECTIVE REACHES OF SAID DRIVE ELEMENT FOR BEING ROTATED THEREBY; COUPLING MEANS MOUNTED ON SAID FILING UNITS, SAID COUPLING MEANS INCLUDING DISPLACEABLE MEANS FOR ENGAGING SAID ROTATABLE ELEMENTS AND BLOCKING ROTATION OF EACH ROTATABLE ELEMENT WITH RESPECT TO THE FILING UNIT ON WHICH IT IS MOUNTED; AND OPEATOR MEANS FOR ALTERNATIVELY OPERATING SAID COUPLING MEANS FOR THE RESPECTIVE ROTATABLE ELEMENTS ON EACH FILING UNIT SO THAT THE FILING UNIT CAN BE DRIVINGLY CONNECTED TO ONE OR THE OTHER OF THE REACHES OF SAID DRIVE ELEMENT.