Cleaning device for fluid filter

Claim 1

EQUIPMENT FOR FILTERING IMPURITIES FROM FLUIDS COMPRISING A CASING HAVING AN INLET PORT FOR UNFILTERED FLUID AND AN OUTLET PORT FOR FILTERED FLUID, MEANS DIVIDING SAID CASING INTO A FIRST AND A SECOND SECTION, MEANS MOUNTING AT LEAST ONE FILTER MEANS IN EACH OF SAID SECTIONS AND DIVIDING EACH SECTION INTO AN UPSTREAM CHAMBER AND A DOWNSTREAM CHAMBER, A CYLINDER IN SAID CASING HAVING A PISTON MOVABLY AND SEALINGLY MOUNTED THEREIN, FIRT PASSAGE MEANS CONNECTING A FIRST END OF SAID CYLINDER TO THE UPSTREAM CHAMBERS AND TO SAID INLET, SECOND PASAGE MEANS CONNECTING THE SECOND END OF SAID CYLINDER TO THE DOWNSTREAM CHAMBERS AND TO SAID OUTLET, FIRST INTERCONNECTED VALVE MEANS HAVING A FIRST POSITION CONTROLLING SAID FIRST AND SECOND PASSAGE MEANS AND CONNECTING SAID INLET PORT TO SAID UPSTREAM CHAMBERS AND SAID DOWNSTREAM CHAMBERS TO SAID CYLINDER, MEANS TO ACTUATE SAID TO THE FIRST END OF SAID CYLINDER PORT WHILE CUTTING OFF FLOW FIRST VALVE MEANS TO A SECOND POSITION CONNECTING THE INLET PORT WITH THE FIRST END OF SAID CYLINDER AND CUTTING OFF FLOW BETWEEN SAID INLET PORT AND THE UPSTREAM CHAMBER IN SAID FIRST SECTION AND BETWEEN SAID OUTLET PORT AND THE DOWNSTREAM CHAMBER LOCATED IN SAID FIRST SECTION, AND FURTHER CONNECTING THE LAST MENTIONED DOWNSTREAM CHAMBER WITH SAID SECOND END OF SAID CYLINDER, A DISCHARGE PART LOCATED IN EACH OF THE UPSTREAM CHAMBERS, SECOND VALVE MEANS NORMALLY CLOSING SAID DISCHARGE PORTS, VALVE OPERATING MEANS OPERATIVELY CONNECTED TO SAID FIRST VALVE OPERATAND ADAPTED TO OPEN THE SECOND VALVE MEANS IN THE DISCHARGE PORT OF THE UPSTREAM CHAMBER IN SAID FIRST SECTION WHEN SAID FIRST VALVE MEANS IS IN SAID FIRST SECTION, SAID AS TO BACKWASH THE FILTER MEANS IN AID FIRST SECTION, SAID FIRST VALVE MERANS BEING CONSTRUCTED AND ARRANGED SO AS TO BE MOVABLE TO A THIRD POSITION WHEREIN THE FILTER MEANS IN SAID SECOND SECTION IS BACKWASHED IN LIKE MANNER, AND SAID CYLINDER HAVING DRAIN MEANS LEADING THEREFROM AND OPERATIVE TO EXHAUST FLUID FROM SAID CYLINDER WHEN SAID FIRST VALVE MEANS IS RETURNED TO SAID FIRST POSITION AFTER BACKWASHING.