Shower tap with delayed automatic shut=off - has groove in piston skirt to control flow to actuating chamber

摘要

A tap (1) for the water supply to a shower bath is actuated by a press button (2) which lifts the push rod (10) and raises the inner valve (12) off its seat. This equalises the pressure in the chamber (5) with the downstream pressure at the outlet (4). Further movement of the press button raises the main valve (6) off its seat (8) and allows water to flow from the inlet (3) to the outlet. When the pressure on the button is released the valve remains open until upstream water flows into the chamber along a groove (14) cut in the skirt of the piston which forms the main valve. The groove is automatically cleaned by the lip of the sealing ring (7) so that there is no risk of failure due to blockage.