Swimming pool water delivering and withdrawal system

Claim 1

IN A SWIMMING POOL, A COMBINED OUTLET DRAIN AND WATER INLET COMPRISING: A SUMP IN THE BOTTOM OF THE POOL EXTENDING BELOW THE BOTTOM SURFACE; A WATER INLET-OUTLET PIPE LEADING INTO SAID SUMP; MEANS FOR SELECTIVELY APPLYING WATER PRESSURE OR WATER SUCTION TO SAID INLET-OUTLET PIPE; A FITTING LOCATED IN SAID SUMP AND HAVING A CHAMBER THEREIN COMMUNICATING WITH SAID INLET-OUTLET PIPE; AN OPENING IN SAID FITTING COMMUNICATING SAID CHAMBER WITH SAID SUMP; VALVE MEANS IN SAID FITTING NORMALLY CLOSING SAID OPENING AND MOVING TO OPEN POSITION IN DIRECTION REPONSE TO SUCTION APPLIED TO SAID WATER INLET-OUTLET PIPE; A SUPPORTING PIPE COMMUNICATING WITH SAID FITTING CHAMBER AND EXTENDING UPWARDLY FROM SAID FITTING AND CARRYING A HOLLOW SUPPORTING POST PROJECTING A SHORT DISTANCE ABOVE THE BOTTOM SURFACE OF THE POOL; A ROTARY NOZZLE MOUNTED ON SAID SUPPORTING POST FOR ROTATION ABOUT AN AXIS SUBSTANTIALLY PERPENDICULAR TO THE BOTTOM SURFACE OF THE POOL, THE DISCHARGE AXIS OF SAID NOZZLE BEING SUBSTANTIALLY PARALLEL TO AND ADJACENT TO SAID BOTTOM SURFACE AND BEING OFFSET LATERALLY FROM ITS AXIS OF ROTATION WHEREBY THE FORCE OF REACTION TO THE EJECTION OF WATER CREATES A TURNING MOMENT TO EFFECT ROTATION OF THE NOZZLE; MEANS DEFINING LATERAL COMMUNICATING OPENINGS IN SAID SUPPORTING POST AND NOZZLE FOR PASSAGE OF WATER THERETHROUGH; AND AN ANTIVORTEX PLATE MOUNTED ABOVE SAID PUMP AND BENEATH SAID ROTARY NOZZLE.