| 摘要 |
1,164,156. Stamping. FREDERICK A. KRAUSE ASSOCIATES Inc. 23 Sept., 1966 [27 Sept., 1965], No. 42547/66. Heading B3Q. A method of drawing sheet metal 28 into cupshape comprises applying pressure against one side of the sheet in spaced regions and simultaneously applying opposite pressure on the other side of the sheet in a region between the spaced regions. The sheet is drawn between dies, Fig. 1, in which the lower die has retracting rings 30, 42 supported respectively on pins 34, connected to an hydraulic cylinder 38, and on pistons 50 in cylinders 52. Co-operating shearing edges on the lower end of the top diesection 14 and upper end of the bottom diesection 24 sever a blank from the sheet at the start of the drawing operation, which is completed in a single stroke of the upper die. Continued downward movement of the upper die retracts the lower, clamping ring 30, Fig. 2, and draws the blank into a shallow cup over the inner ring 42. Both rings 30, 42 now retract as a tubular, inner member 18 of the upper die enters an annular space 64 in the lower die, Fig. 3 (not shown). The operation ends with the blank formed over the central member 62 of the lower die and trimmed at its lower end between a ridge 66 in the space 64 and the end of member 18. |
