Patent GB-1272694-A (GB)
Title: Water closet flushing systems
IPC: E03D5/09
Filed: 1970-10-15
Abstract: 1,272,694. Water closet flushing systems. PHILIPS' GLOEILAMPENFABRIEKEN N.V. 15 Oct., 1970 [18 Oct., 1969], No. 49025/70. Heading E1C. [Also in Division F2] In a water closet flushing system of the kind including a float-controlled valve to control the filling of a cystern and a means whereby a flushing and filling cycle is performed automatically on reception of a start impulse, a start valve applies a pressure signal to a hydraulically operated control device which is adapted to control both the flushing and filling of the cystern according to a programme and which includes hydraulically operated initiating means for initiating the flushing stage. In one diagrammatically illustrated embodiment, Fig. 1, the depression of start button 11 causes a flow of water from inlet 6 through resistance R1 to cause lowering of the pressure in the upper chamber of a relay valve 12 so that its diaphragm lifts to supply water via resistance R6 to an annular chamber 20 of motor 4 where it acts differentially on diaphragms 14, 15 to raise a flushing valve 5, the pressure built up across R6 causing a hold valve 10 to open so that the circuit remains operational after button 11 has been released. At the same time, the pressure built up on the downstream side of R6 acts in chamber 21 of a blocking valve 16 which is interposed between a relay valve 22, associated with a float-controlled valve 8, and water inlet valve 3 which supplies water to the cystern, so that although the fall in water level during flushing operates the valves 8 and 22, operation of valve 3 is prevented for a period sufficient for flushing to be complete, this period being determined by a timer 17 which consists of a chamber 18 supplied with water via resistances R6 and R2 to cause a diaphragm to compress a spring 19. When the diaphragm has fully compressed spring 19 the consequent build up of pressure in chamber 18 acts in the upper chamber of hold valve 10 to shut off the supply of water through the resistance R6, upon which a spring 7 commences to return the valve 5 to closed position, the water in chamber 20 exhausting via R2 and a bleed resistor R3. When valve 5 is fully returned to seated position pressure on the downstream side of R6 falls to zero, and, since chamber 21 is now at atmospheric pressure, the blocking valve 16 opens and filling commences. When the water level in the cystern has been restored valves 8 and 22 re-close and the circuit is restored to its initial condition. In the practical embodiment of Fig. 2, the timer 17 is omitted, this being made possible by a feed-back circuit from the chamber 57 of the motor 4 via passage 64 to control chamber 65 of a changeover valve 25. When start button 11 is depressed valve 49 opens to feed water from supply 40, 41, which is at a pressure determined by pressure reducer 27, via R7 and R8 to the chamber 57, R8 being subsequently by-passed, since the pressure opens check valve 30, while at the same time exhaust valve 29 is operated to close exhaust 78. Rise of pressure in 57 operates valve 25 so that a supply to float-operated valve 24 is held off, valve 24 instead being exhausted via exhaust 69, so preventing operation of a blocking valve 23 in the unblocking direction, as a result of which, when, owing to raising of valve 5 by the piston 58, flushing commences and the float-carrying lever 70 descends, either due to its own weight or assisted by a spring (95, Fig. 4, not shown) the filling valve 76 remains closed. When piston 58 has moved its full stroke, the rocking lever 59 connecting it to the valve 5 abuts a stop 77, causing a further rise in pressure in chamber 57 which causes valve 49, previously held open by the supply pressure, to re-close. The elasticity of the diaphragm of valve 29 is sufficient to cause it to open the exhaust 78 so that piston 58 can return and valve 5 is re-closed. At this stage, pressure ceases to exist in chamber 65 and float-operated valve 24 is then made operative to supply water from conduit 47 to operate blocking valve 23 so as to remove its blocking effect on filling valve 76 and allow filling. After filling is complete, the circuit is restored to its initial condition.