Automatic backwash sand filter and process of cleaning same

Claim 1

AN AUTOMATIC BACKWASH SAND FILTER COMPRISING A TANK, SUBSTANTIALLY HORIZONTAL POROUS MEANS TO SUPPORT A SAND BED IN THE LOWER PORTION OF SAID TANK, MEANS TO DELIVER INFLUENT FLUID TO BE FILTERED TO THE UPPER PORTION OF SAID TANK ABOVE A SAND BED WHEN FORMED IN SAID TANK, AND FLUID-RECEIVING MEANS BENEATH SAID POROUS SUPPORT MEANS FOR THE RECEPTION OF FILTERED FLUID THEREFROM, SAID FLUID-RECEIVING MEANS HAVING AN ELONGATED SURFACE ALONG THE LOWER PORTION OF ONE SIDE OF SAID TANK PROVIDED WITH A ROW OF PORTS THROUGH WHICH FLUID EXISTS FROM SAID FLUIDRECEIVING MEANS, IN COMBINATION WITH BACKWASHING MEANS MOVEBLE ALONG A PATH BETWEEN OPPOSITE ENDS OF SAID TANK AND INCLUDING A CARRIAGE MOVABLE ALONG THE UPPER PORTION OF THE TANK, AN ARM DEPENDING FROM SAID CARRIAGE ADJACENT THE EXTERIOR OF SAID ONE SIDE OF SAID TANK HAVING SAID ELONGATED SURFACE ALONG THE LOWER PORTION THEREOF, PIVOT MEANS CONNECTING THE UPPER END OF SAID ARM TO SAID CARRIAGE FOR LIMITED LATERAL MOVEMENT OF THE LOWER END OF SAID ARM TOWARD AND FROM SAID ELONGATED SURFACE ALONG THE LOWER PORTION OF ONE SIDE OF SAID TANK, COMPRESSIBLE MEANS SUPPORTED BY SAID CARRIAGE AND ENGAGING SAID ARM BELOW SAID PIVOT MEANS AND OPERABLE TO YIELDABLY URGE SAID LOWER END OF SAID ARM TOWARD SAID ELONGATED SURFACE AS ARORESAID, PUMP MEANS CARRIED BY SAID CARRIAGE, FLEXIBLE FLUID CONDUIT MEANS HAVING AN INLET END CONNECTED TO SAID PUMP MEANS, A SHOE, MEANS CONNECTING SAID SHOE FLEXIBLY TO THE LOWER END OF SAID ARM FOR SUPPORT THEREBY AND MEANS CONNECTING SAID SHOE TO THE DISCHARGE END OF SAID CONDUIT MEANS, SAID SHOE HAVING SURFACE SLIDABLY ENGAGING SAID ELONGATED SURFACE OF SAID FLUID-RECEIVING MEANS IN LINE WITH SAID ROW OF PORTS THEREIN AND COMMUNICATING SELECTIVELY WITH SAID PORTS, THEREBY TO PERMIT THE FLOW OF WASHFLUID THROUGH SAID PORTS INTO SAID FLUID-RECEIVING MEANS AND UPWARD THROUGH SAID POROUS SUPPORT FOR A SAND BED TO EFFECT FLUSHING OF ACCUMMULATED IMPURITIES FROM A SAND BED WHEN FORMED UPON SAID POROUS SUPPORT, AND COMPRESSIBLE YIELDABLE PRESSURE MEANS CARRIED BY THE LOWER END OF SAID ARM AND INTERPOSED BETWEEN SAID SHOE AND MEANS FIXED TO THE LOWER END OF SAID ARM AND IN CONJUNCTION WITH THE FORCE OF SAID COMPRESSIBLE MEANS ENGAGING SAID ARM COMPRISING THE ONLY MEANS OPERABLE TO URGE SAID SLIDABLE SURFACE THEREOF FIRMLY AND YIELDABLY INTO CLOSE SLIDING AND SEALING CONFORMITY AGAINST SAID ELONGATED PORTED SURFACE ALONG SAID ONE SIDE OF SAID FLUID-RECEIVING MEANS TO INSURE SUBSTANTIALLY NO LEAKAGE BETWEEN SAID SLIDABLY ENGAGED SURFACES DURING TRAVEL OF SAID SHOE RELATIVE TO SAID ELONGATED SURFACE AS SAID CARRIAGE MOVES ALONG SAID TANK.

Claim 3

A METHOD OF OPERATING AN AUTOMATIC BACKWASH FILTER SYSTEM COMPRISING MEANS TO SUPPORT A SAND BED WITHIN AN ELONGATED TANK UPON POROUS MEANS THROUGH WHICH FILTERED FLUID DRAINS, BACKWASH MEANS MOUNTED ON A MOVABLE CARRIAGE MOVABLE ALONG SAID BED AND OPERABLE TO FORCE FILTERED FLUID UPWARDLY THROUGH SUCCESSIVE SECTIONS OF SAID POROUS MEANS TO FLUSH ACCUMMULATED MATERIAL FROM THE UPPER PORTION OF SAID SAND BED FOR REMOVAL THEREFROM TO CLEAN SAID BED, AND CONTROL MEANS FOR SAID BACKWASH MEANS RESPONSIVE TO A PREDETERMINED CONDITION OF SAID FILTER SYSTEM TO START AND STOP THE OPERATION OF SAID BACKWASH MEANS, SAID METHOD COMPRISING THE STEPS OF DELIVERING FLUID TO BE FILTERED TO THE UPPER PORTION OF SAID TANK, FILTERING SAID FLUID BY GRAVITY THROUGH SAID SAND BED UNTIL MATERIAL ACCUMMULATED ON THE UPPER PORTION OF SAID BED HAS REDUCED THE FILTERING RATE THEREOF TO A PREDETERMINED AMOUNT, COMMENCING OPERATION OF SAID BACKWASH MEANS AT ONE END OF SAID TANK WHEN SAID REDUCED AMOUNT OF FILTERING RATE HAS BEEN REACHED AND CONTINUING SAID BACKWASH ING THROUGH SUCCESSIVE COMPLETE PASSES OF SAID BACKWASH MEANS BETWEEN ENDS OF SAID TANK UNTIL THE FILTERING RATE OF SAID BED HAS BEEN RESTORED TO A PREDETERMINED RATE, AND DISCONTINUING SAID BACKWASH OPERATION WHEN SAID CARRAIGE HAS REACHED ONE END OF SAID TANK, SAID CARRIAGE REMAINING AT SAID ONE END OF SAID TANK UNTIL SAID BACKWASH CONTROL MEANS IN RESPONSE TO A PREDETERMINED CONDITION O SAID FILTER SYSTEM, ACTUATES THE CARRIAGE AND BACKWASHING MEANS, THEREBY REPEATING THE CYCLE.

Claim 4

A METHOD OF OPERATING AN AUTOMATIC BACKWASH FILTER SYSTEM COMPRISING MEANS TO SUPPORT A SAND BED WITHIN AN ELONGATED TANK UPON POROUS MEANS THROUGH WHICH FILTERED FLUID DRAINS, BACKWASH MEANS MOUNTED ON A MOVABLE CARRIAGE MOVABLE ALONG SAID BED AND OPERABLE TO FORCE FILTERED FLUID UPWARDLY THROUGH SUCCESSIVE SECTIONS OF SAID POROUS MEANS TO FLUSH ACCUMMULATED MATERIAL FROM THE UPPER PORTION OF SAID SAND BED FOR REMOVAL THEREFROM TO CLEAN SAID BED, AND CONTROL MEANS FOR SAID BACKWASH MEANS RESPONSIVE TO A PREDETERMINED CONDITION OF SAID FILTER SYSTEM TO START AND STOP THE OPERATION OF SAID BACKWASH MEANS, SAID METHOD COMPRISING THE STEPS OF DELIVERING FLUID TO BE FILTERED TO THE UPPER PORTION OF SAID TANK, FILTERING SAID FLUID BY GRAVITY THROUGH SAID SAND BED UNTIL MATERIAL ACCUMMULATED ON THE UPPER PORTION OF SAID BED HAS REDUCED THE FILTERING RATE THEREOF TO A PREDETERMINED AMOUNT, COMMENCING OPERATION OF SAID BACKWASH MEANS AT ONE END OF SAID TANK WHEN SAID REDUCED AMOUNT OF FILTERING RATE HAS BEEN REACHED AND CONTINUING SAID BACKWASH ING THROUGH SUCCESSIVE COMPLETE PASSES OF SAID BACKWASH MEANS BETWEEN ENDS OF SAID TANK UNTIL THE FILTERING RATE OF SAID BED HAS BEEN RESTORED TO A PREDETERMINED RATE, AND DISCONTINUING SAID BACKWASH OPERATION WHEN SAID CARRAIGE HAS REACHED ONE END OF SAID TANK, SAID CARRIAGE REMAINING AT SAID ONE END OF SAID TANK UNTIL SAID BACKWASH CONTROL MEANS IN RESPONSE TO A PREDETERMINED CONDITION O SAID FILTER SYSTEM, ACTUATES THE CARRIAGE AND BACKWASHING MEANS, THEREBY REPEATING THE CYCLE.