| 摘要 |
<p>An electropneumatic valve control serves for the changeover from vacuum to atmospheric pressure in a working apparatus and is used, for example, as a pulsator for a milker used in vacuum milking installations. The valve control contains a main valve and an auxiliary valve, the main valve being in the form of a conical valve and serving for the communication between the working apparatus on the one hand and the vacuum source and the atmosphere on the other. The auxiliary valve serves for the control of the main valve which is fastened to a diaphragm. The auxiliary valve is in the form of a slide valve and has a recess into which a connecting passage opens during both the working phase and the rest phase of the control, and the connecting passage is connected to a chamber that is continually under vacuum. In the working phase the recess in the control slide valve establishes a connection between the connecting passage and a passage connected to the diaphragm chamber, the control slide valve being actuated by means of a double-action solenoid and the passage connected to the diaphragm chamber being connected to the external atmosphere in the rest phase of the control.</p> |
