Water-treating apparatus

Claim 1

IN WATER-TREATING APPARATUS PROVIDING TANK MEANS INCLUDING A HORIZONTALLY-EXTENDING UNDERDRAIN PLATE AND DRAIN MEANS BENEATH SAID PLATE A FINELY-DIVIDED TREATING MEDIA SUPPORTED ON SAID PLATE, SAID PLATE HAVING A PLURALITY OF OPENINGS THEREIN THROUGH WHICH THE TREATED WATER PASSES DOWNWARDLY TO SAID UNDERDRAIN MEANS AND ALSO THROUGH WHICH WATER PASSES IN THE OPPOSITE DIRECTION ON THE BACKWASHING CYCLE, A MEDIA-RETAINING SCREEN ASSEMBLY MOUNTED IN COVERING RELATION WITH EACH OF SAID PLATE OPENINGS AND COMPRISING A HOUSING UPSTANDING FROM SAID UNDERDRAIN PLATE, SAID HOUSING INCLUDING AT LEAST END AND SIDE WALLS, AT LEAST ONE OF SAID END AND SIDE WALLS BEING CONSTRUCTED OF SCREEN MATERIAL SIZED TO PREVENT PASSAGE OF SAID FINELY-DIVIDED TREATING MEDIA, AN ELONGATED ELEMENT INTERCONNECTING SAID UNDERDRAIN PLATE WITH EACH SCREEN ASSEMBLY, SAID ELONGATED ELEMENT EXTENDING THROUGH THE OPENING ASSOCIATED ELEMENT EXTENDING BETWEEN SAID ASSEMBLY END WALL AND THE SIDE OF SAID PLATE OPPOSITE THE SIDE CONFRONTING SAID ASSEMBLY, SAID ELEMENT INCLUDING RESILIENT MEANS FOR BIASING SAID ASSEMBLY TOWARD SAID PLATE AND CAPABLE OF BEING FLEXED UNDER EXCESSIVE BACKWASH OF WATER PRESSURE OF THE ORDER OF ABOUT FIVE P.S.I. TO ABOUT 20 P.S.I. ACROSS SAID PLATE TO PROVIDE A SPACING OF SAID ASSEMBLY RELATIVE TO SAID PLATE TO PROVIDE A SUPPLEMENT FLOW PASSAGE FOR SAID BACKWASH WATER.