PILOT-OPERATED FIVE-WAY TWO-POSITION SPOOL-TYPE PNEUMATIC DIRECTIONAL VALVE MECHANISM

When compressed (pilot) air is admitted through threaded port a in cover 1 (Fig. a), spool 2 is shuttled to the right. At the same time air passes through a metering orifice in a connection and central channel in spool 2 and begins to fill space 3. As the space is filled, the pressure in it rises. Since the effective area of the spool at its right end is twice that at its left end, owing to the pr…