Flow control for rinsing machine - includes valve regulated by weight of workpieces on rack on base of rinsing tank

摘要

The flow control system for an automatic rinsing machine includes a bath (1) through which water circulates, entering via a pipe (14) and leaving through an overflow (4). Flow of water is controlled by a valve (10) having a movable piston (22) inside a cylinder (11). A small diameter pipe (17) leads from the side of the cylinder to a sensing switch (30). This is connected to a spring biased platform under the rinsing water surface, so that the pipe (17) is shut off when the platform is not loaded, but open when the platform is loaded. The piston adopts one of two positions in the cylinder according to whether it is possible for water to escape through the side tube. When the side tube is shut off, the piston moves towards the valve outlet (13) shutting it off. It opens when the platform is loaded. Several such controlled rinsing baths may be used in the cleaning of semiconductors during manufacture.