Filter unit for swimming pool

Claim 1

A FILTER ASSEMBLY FOR A SWIMMING POOL HAVING AN OUTLET, COMPRISING A NORMALLY UPRIGHT CASING HAVING A LOWER END WALL, A PARTITION WITHIN SAID CASING DIVIDING THE LATTER INTO A LOWER FILTER TANK AND AN UPPER COLLECTOR TANK, SAID CASING HAVING A FIRST LATERAL INLET TO SAID COLLECTOR TANK FOR COMMUNICATION WITH THE SURFACE WATER LEVEL OF THE POOL, AN OUTLET FROM SAID COLLECTOR TANK, AN INLET TO SAID FILTER TANK IN SAID LOWER END WALL, AND AN OUTLET FROM SAID FILTER TANK IN SAID LOWER END WALL, SAID PARTITION HAVING AN OPENING COMMUNICATING SAID COLLECTOR TANK TO THE UPPER END OF SAID FILTER TANK, A ROTATABLE VALVE PLATE ON SAID PARTITION FOR SELECTIVELY OPENING AND CLOSING SAID OPENING, A VALVE ON SAID CASING HAVING A FIRST INLET CONNECTED TO SAID COLLECTOR TANK OUTLET, A SECOND INLET FOR CONNECTION TO THE POOL OUTLET, AND AN OUTLET CONNECTED TO SAID FILTER TANK INLET, SAID VALVE INCLUDING MEANS FOR SELECTIVELY BLOCKING WATER FLOW FROM SAID VALVE INLETS TO SAID VALVE OUTLET, SURFACE SKIMMING MEANS IN SAID COLLECTOR TANK BETWEEN SAID COLLECTOR TANK INLET AND SAID COLLECTOR TANK OUTLET, A HOLLOW PERMEABLE FILTER ELEMENT WITHIN SAID FILTER TANK HAVING AN OUTLET, ROTATABLY RELEASABLE AND ENGAGEABLE MEANS COUPLING SAID FILTER ELEMENT OUTLET TO SAID FILTER TANK OUTLET, A HANDLE SECURED TO SAID FILTER ELEMENT AND EXTENDING THROUGH SAID PARTITION INTO SAID COLLECTOR TANK FOR ROTATING SAID ELEMENT TO RELEASE AND ENGAGE SAID COUPLING MEANS AND MOVE SAID ELEMENT ABOUT IN SAID FILTER TANK WHEN SAID COUPLING MEANS ARE RELEASED, SAID COLLECTOR TANK HAVING AN OPEN TOP THROUGH WHICH SAID HANDLE IS ACCESSIBLE, AND A CONNECTION BETWEEN SAID HANDLE AND VALVE PLATE WHEREBY THE LATTER IS OPENED BY ROTATION OF SAID HANDLE TO RELEASE SAID COUPLING MEANS AND CLOSED BY ROTATION OF SAID HANDLE TO ENGAGE SAID COUPLING MEANS.