Apparatus for cleaning filters

Claim 1

THE COMBINATION WITH AN AIR FILTER OF AN APPARATUS FOR CLEANING THE FILTER COMPRISING A SUCTION CLEANING NOZZLE POSITIONED CLOSELY ADJACENT ONE FACE OF THE FILTER AND CONNECTED TO A SOURCE OF SUCTION FOR APPLYING A SUCTION CLEANING FORCE TO THE FILTER, MEANS FOR PROPELLING SAID NOZZLE ACROSS THE FILTER COMPRISING ELONGATE GUIDE MEANS EXTENDING ACROSS THE FILTER, FIRST AND SECOND INTERCONNECTED RELATIVELY MOVABLE MEMBERS GUIDED FOR MOVEMENT ALONG SAID GUIDE MEANS, MEANS MOUNTING SAID NOZZLE ON ONE OF SAID MEMBERS, POWER MEANS FOR APPLYING SIMULTANEOUSLY DIRECTIONALLY OPPOSITE RELATIVE FORCE TO THE RESPECTIVE MEMBERS IN A DIRECTION SUBSTANTIALLY PARALLEL TO SAID GUIDE MEANS SUCH THAT EACH MEMBER TENDS TO MOVE IN THE OPPOSITE DIRECTION FROM THE OTHER MEMBER, CONTROL MEANS FOR CONTROLLING SAID POWER MEANS SO SAID FORCE ACTS AGAINST SAID FIRST MEMBER IN ONE LONGITUDINAL DIRECTION, RESTRAINING MEANS SPACED LONGITUDINALLY OF SAID GUIDE MEANS FOR SUCCESSIVELY RESTRAINING SAID SECOND MEMBER AGAINST MOVEMENT IN A DIRECTION OPPOSITE FROM SAID ONE DIRECTION RELATIVE TO SAID GUIDE MEANS SO THAT SAID FIRST MEMBER IS ADVANCED A STEP IN SAID ONE DIRECTION ALONG SAID GUIDE MEANS AND RELATIVE TO SAID SECOND MEMBER UNDER IMPETUS OF THE APPLIED DIRECTIONALLY OPPOSITE RELATIVE FORCE, MEANS APPLYING A YIELDABLE RESTRAINING FORCE TO SAID FIRST MEMBER RELATIVE TO SAID GUIDE MEANS AND INDEPENDENTLY OF SAID SECOND MEMBER, MEAN RESPONSIVE TO PREDETERMINED ADVANCING MOVEMENT OF SAID FIRST MEMBER RELATIVE TO SAID SECOND MEMBER FOR OPERATING SAID CONTROL MEANS TO REVERSE THE DIRECTION IN WHICH THE FORCE APPLIED BY SAID POWER MEANS IS ACTING AGAINST SAID FIRST MEMBER SO AS TO ADVANCE SAID SECOND MEMBER ALONG SAID GUIDE MEANS IN SAID ONE DIRECTION AND RELATIVE TO SAID FIRST MEMBER UNDER THE IMPETUS OF THE APPLIED DIRECTIONALLY OPPOSITE RELATIVE FORCE, AND SAID FIRST-NAMED RESTRAINING MEANS BEING LOCATED SO AS TO AGAIN RESTRAIN SAID SECOND MEMBER UPON PREDETERMINED ADVANCING MOVEMENT OF SAID SECOND MEMBER ALONG SAID GUIDE MEANS.