| 摘要 |
<p>1,201,776. Valves. ALFRED TEVES G.m.b.H. 20 Sept., 1967 [22 Sept., 1966], No. 42770/67. Heading F2V. A changeover valve has a connection A to load, a connection B to vacuum, and a connection C to air pressure, and comprises a closure member formed by a lip 12 on a member 4 acting on a diaphragm 7 backed by a piston 6, and another closure member formed by the end face of a slide member 5 acting on a seal 8, the member 5 being axially movable in the piston 6 and locating a stem 11 of the member 4, and a spring 3 loading the piston towards the connection C. As shown the valve is open between the load A and vacuum B. Connection C is at atmospheric pressure. Upon an increase in pressure at C, the assembly 4, 5, 6 and 7 is forced downwards to close off vacuum B. A further increase in pressure forces the diaphragm 7 off the lip 12 and opens a connection through the member 5 between C and A. In Fig. 2 (not shown), the end of a stem (114) closes on to a seal (108) to control the vacuum connection (B), and air pressure at (C) acts on a piston (106).</p> |
