| 摘要 |
<p>1303320 Making valves MACHINEFABRIEK EN IJZERGIETERIJ "HOLLAND-BERGEN OP ZOOM" NV 13 April 1970 [6 Nov 1969] 17525/70 Heading B3A [Also in Division F2] A gate valve has its gate formed from a pair of discs 7, 8 pressed from sheet metal to have a raised edge 9 which is higher at the top of the gate to give the gate a wedge-shaped section. The discs are welded together 11 and the edges have recesses 12 at the sides so that the disc can be guided by ribs (13), Fig. 1 (not shown), in the valve casing. The highest part of the edge of each disc is also recessed to receive a grooved nut 15. The inside of each disc may be reinforced by ribs (24), Fig. 3 (not shown). The recesses 12 may have a channel shaped guide (22), Fig. 7 (not shown), or a guide plate (23), Fig. 8 (not shown), welded therein. The gate may have flat layers (21), Fig. 6 (not shown), welded thereto to form a sealing surface.</p> |
