| 摘要 |
<p>The spray valve comprises a cylindrical component having a central passage, which body is slidingly disposed in a widened portion of the valve body. The crosssectional area of the central passage is smaller than that of the widened portion, so that the cylindrical component is displaced outwardly against the return force of a spring by the flow occuring when the spray valve is opened. A permanent magnet is embedded in the wall of the cylindrical component. In the wall of the valve body surrounding the widened portion thereof there is a blind bore in which a reed contact is inserted. Through the flow of liquid occuring when the spray valve is opened, the magnet is displaced into the field of response of the reed contact, which thus indicates the opening of the spray valve. This spary valve is intended to be utilized in a system for spraying a thawing agent. A plurality of control circuits are disposed along a roadway, one of the spray valves being associated with each control circuit. The reed contacts make possible a remote indication of the operating readiness of the individual spray valves, making the spraying system much more reliable.</p> |
