| 摘要 |
1,210,454. Stamping; die cushions. E. W. BLISS CO. 11 July, 1968 [13 July, 1967], No. 33203/68. Headings B3H and B3Q. [Also in Division F2] A self-contained die cushion comprises a first sleeve 20 on which is slidably mounted a second sleeve 50, the ends 24 and 52 of each sleeve defining a cushion chamber 70 with sleeve 50 biased upwardly by a compressible fluid, and a wall within sleeve 20 dividing chamber 70 into two fluid tight chambers 100, 102 such that when chamber 100 is exhausted the upper sleve 50 can descend to its lowest position b at which point it is inoperative. In the embodiment of Fig. 1 the wall is a piston 90 which is slidable within sleeve 20 and at its uppermost point abuts flange 42 on sleeve 20. The chamber 100 may be filled and exhausted by means of a three-way tap 86 and channel 80. In an alternative form, Fig. 9, the wall is a flexible diaphragm 222 which is limited for upward movement by a perforated plate 224. The die cushion can be fitted with an hydraulic shock absorbing device, Fig. 2 (not shown), or an hydraulic snubber, Fig. 4 (not shown). |
