Abstract
Described in this paper, is a pneumatic logic device which functions as an exclusive-OR gate. Two similar sets of bellows are built in an enclosure and they divid the enclosure into three chambers. The movable ends of both of the sets of bellows are closed and connected with a plate each other. The inside chamber of the enclosure opens to the atmosphere with a vent orifice and connected to an air source through a nozzle with rect-angular section provided on the enclosure wall. The nozzle faces a side plane of the plate at a very small distance. Air is supplied from a constant pressure source into the enclosure through the nozzle and flows out to the atomosphere through the vent orifice. Input pressures are introduced in the sets of bellows and the pressure in the enclosure serves as output of the device. When the pressure of the same level are put in both of the set of bellows, the plate positions as to block the outlet and the output pressure maintains a low level, because of very large fluid circuit resistance of the nozzle outlet. When a high pressure is put into one side of the sets of bellows and a low pressure is put in the other side, the plate displaces as to open the nozzle outlet and the output pressure maintains high level. When the source pressure is supplied from the orifice to the enclosure and the nozzle is opened to the atmosphere, this device can function as an exclusive-NOR gate.
