VORRICHTUNG ZUR WEGESTEUERUNG DES DRUCKMITTELS ZU UND VON EINEM DOPPELTWIRKENDEN PNEUMATISCHEN SERVOMOTOR

摘要

A fluid flow control element for use in apparatus for reciprocating a working piston in a pneumatic drive system includes a plurality of orifices interconnected within the element by passages through which flow is controlled by means of two cap-shaped seals. The seals are arranged in the spaces defined by two pairs of opposed generally conical surfaces. The apparatus includes a directional control valve 3/2 arranged to connect one of the orifices either to a source of pneumatic pressure or to atmosphere and a pressure reservoir connected to another orifice. Two further orifices are connected to opposite ends of a cylinder in which the working piston moves. The arrangement provides for control of the working piston by means of the directional control valve 3/2.