| 摘要 |
1,175,977. Valves. DRESSER INDUSTRIES Inc. 12 Dec., 1966 [14 Dec., 1965; 31 Oct., 1966], No. 35393/67. Divided out of 1,175,975. Heading F2V. A butterfly-valve closure member has a peripheral rubber gasket with two concentric ribs 18, secured by a plurality of screws 14, so that it can be deformed radially by tightening the screws. |
