Automatisches Entlüftungsventil für Hydraulikanlagen

摘要

The invention calls for an optical fibre made of a material which is optically denser than gas to be fitted between an optical transmitter (9) and an opto-electric receiver (11), at least one external surface of the optical fibre being disposed in such a way in a space to which gas or hydraulic fluid can be admitted that, when gas is in contact with the external surface, light reaches the receiver (11) and when hydraulic fluid is in contact with the surface no light reaches the receiver, and that the receiver, when it receives light, generates an output signal which opens a solenoid valve (14) fitted in an outlet channel (15, 16) between the space (5) in which the optical fibre is located and an external space.