| 摘要 |
<p>1,138,088. Valves. GRINNELL CORP. 15 Nov., 1966 [15 Nov., 1965], No. 51204/66. Addition to 1,060,169. Heading F2V. The valve of the parent specification is modified in respect of the actuating means for the diaphragm compressors (72, 94). In the form shown, the inner and outer compressors 342, 344 are connected through concentric stems 354, 344a to separate fluid pressureoperated diaphragms 346, 348 of which the one operating the outer compressor is of greater effective area than the other. A single pressure source connectible selectively to three chambers 370, 372 and 374 respectively above, between, and below the two diaphragms 346, 348, can be used to operate the valve. Thus in open position shown, the top chamber is exhausted. To close the outer compressor the bottom chamber is also exhausted. Finally the top chamber is pressurized to close the inner compressor. In a second form a single operating diaphragm (396a), Fig. 4 (not shown), is used and is connected to the inner compressor. The two compressors are individually spring- loaded from the top of the bonnet (386). In a third form, a first hand wheel (326) operates the outer compressor through a screwed stem (320a). This stem carries a second hand wheel (334) operating the inner compressor, also through a screwed stem (336). In a fourth form, a single hand wheel operates a stem of the inner compressor, the outer compressor being spring loaded from the top of the bonnet.</p> |
