| 摘要 |
<p>1,256,285. Valves. GRINNELL CORP. 9 Sept., 1969 [13 Sept., 1968], No. 44421/69. Heading F2V. In a rotary cylindrical plug cock the body cavity is formed with opposed longitudinally extending recesses 40, 42, Fig. 4, which are as deep or deeper than opposed lobes 54, 56 on the resilient plug 8 so that in the position shown the lobes are relaxed in the recesses but on rotation through 90 degrees they are compressed about the ports 30, 34 to close the valve. Each lobe has a recess 61 of the same diameter as the ports 30, 34. The dimensions of the lobe are equal to the dimensions of each cylindrical portion of the cavity surrounding one of the ports 30, 34. In a modification the plug may be cylindrical and of a diameter between that of the recesses and cylindrical portions. In another embodiment, Fig. 11, a plug with a recess 142 for selectively connecting the ports 116, 112, 120 has three lobes 134, 136, 138 with recesses 152 and two or three recesses in the cylindrical cavity at 124, 126 and optionally at 128. The plug in each embodiment is rubber moulded about a metal core to which an operating handle is secured.</p> |
