Pressure fluid filters

Claim 1

A SELF-CLEANING PRESSURE FLUID FILTER INCLUDING A VESSEL HAVING AN INLET CHAMBER HAVING AN INLET MEANS AND AN OUTLET CHAMBER HAVING AN OUTLET MEANS, PARTITION MEANS SEPARATING THE INLET AND OUTLET CHAMBERS, A PLURALITY OF SUBSTANTIALLY PARALLEL FILTER ELEMENTS ARRANGED IN AT LEAST ONE ARC ABOUT A COMMON AXIS WITHIN THE OUTLET CHAMBER AND HAVING INLET ENDS COMMUNICATING WITH THE INLET CHAMBER THROUGH THE PARTITION MEANS WHEREBY FLUID FLOW UNDER PRESSURE THROUGH THE VESSEL IS FORCED THROUGH THE FILTER ELEMENTS, REVERSE FLOW CLEANING MEANS MOUNTED FOR ROTATION IN SAID VESSEL AND HAVING A DISCHARGE PASSAGE FOR SUCCESSIVE COMMUNICATION WITH THE INLET ENDS OF SAID FILTER ELEMENTS TO PERMIT FLUID FROM SAID OUTLET CHAMBER TO FLOW IN A REVERSE DIRECTION THROUGH SAID ELEMENTS INTO SAID DISCHARGE PASSAGE, MEANS FOR RESTRICTING FLOW THROUGH THE DISCHARGE PASSAGE, AND PRESSURE RESPONSIVE MEANS EXPOSED TO THE PRESSURE OF THE FLUID IN THE DISCHARGE PASSAGE AND TO THE PRESSURE OF THE FLUID IN SAID OUTLET CHAMBER FOR OPENING TO SAID CHAMBER TO ADMIT FLUID FROM SAID CHAMBER INTO SAID PASSAGE WHEN THE DIFFERENTIAL BETWEEN SAID PRESSURES EXCEEDS A PREDETERMINED AMOUNT.