| 摘要 |
909,775. Closures for resisting fluid pressure. BABCOCK & WILCOX Co. Aug. 24, 1961 [Aug. 29, 1960], No. 30568/61. Class 123 (1). [Also in Group XXV] In a closure fitting for an opening in a wall of a pressure vessel, for example, a hand-hole on a hoden drum, which comprises an elliptical head 15 having a threaded stem 19 on which a nut 21 is tightened to draw the head on to a gasket 18 on an internal seating 13, a flanged collar 34, a series of Belleville springs 31 and a washer 27 are interposed between the nut and a binder 25 which engages on an external seating 14. As the nut is tightened the springs 31 transmit the load resiliently to the gasket, convex and concave surfaces on the washer 27 and binder 25 co-operating to adjust for seating irregularities. To serve as an indicating means for an operator when the requisite amount of force has been transmitted to the gasket to ensure a fluid-tight seal a stop ring 35 is mounted so as to be freely rotatable by hand on a boss 36 on the collar 34. When the nut has been tightened sufficiently the ring becomes wedged between the flange 37 of the collar and the depressed Belleville springs 31. In use, the springs 31 maintain a controlled pressure on the gasket irrespective of pressure variations within the vessel. An eye bolt 24 to which a line is attached to prevent the connected parts from dropping into the vessel is provided on the end of the stem 19. In modifications, Figs. 5 and 6 (not shown), the Belleville springs are stacked either singly or in nested pairs with their concave faces opposed.
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