| 摘要 |
<p>1435930 Valves EMHART (UK) Ltd 30 July 1974 [10 Aug 1973] 37910/73 Heading F2V In a valve for use in glassware forming machines, variable restricted flow is provided for flow between a port 3 and a port 4 connected to a cylinder and unrestricted flow is permitted in the reverse direction. A double frusto-conical seat 11, 12 is provided in a sleeve 8 and a frustoconical valve member 13 co-operates with the seat 12. The valve member is a sliding fit on a stem 17 and is loaded by a spring 19 towards the seat 12 and a stop 18 on the stem. The position of this stop, and hence the aperture between the closure member and the seat, is varied by moving the stop longitudinally, the stem 17 being an extension of a screw-threaded stem 14, 15. A nylon pin 9 secures the sleeve 8 to a screw-threaded plug 6 and provides frictional resistance to turning of the stem. For flow in the reverse direction the valve acts as a spring- loaded check valve. In another embodiment, Fig. 2 (not shown) flow from port 3 to port 4 is unrestricted but flow in the reverse direction is restricted. In this case the valve member co-operates with the seat 11 and slides upwardly on its guiding stem in the check valve mode of operation, a stop (22) being provided on the lower end of the stem. In an alternative embodiment providing restricted flow in each direction, Fig. 3 (not shown), there are two valve members, each spring- loaded and sliding on an adjustable stem, co-operating respectively with the two valve seats 11, 12. The screw-threaded stem (14a) (on the lower valve member) extends downwardly through the valve body.</p> |
