| 摘要 |
1,098,888. Bidet piercing; extruding. LINDEMANN MASCHINENFABRIK G.m.b.H. June 10, 1965 [Aug. 7, 1964], No. 24638/65. Headings B3H and B3P. In an extrusion press having a billet piercing mandrel 5 which may be held stationary during extrusion or may move relatively to the extrusion ram 1, the mandrel is driven by a carriage 4 movable relatively to the ram frame 2 and the positions of the carriage before and after extrusion are determined by stops 38, 42 on a common adjustable member 31, which stops engage respectively with an abutment on the ram frame 2 and with a stationary abutment 25 which is movable from an operative to an inoperative position. The press ram is actuated by piston 27 in stationary cylinder 26. Piston 27 provides a cylinder 28 for piston 29 which actuates the carriage 4 for the mandrel 5. A pair of threaded spindles 31 in carriage 4 are adjusted simultaneously by gears 34 and each carry a stop 38 which engages the rear wall of the ram frame 2 for fixing the initial position of the mandrel. Stops 42 on the spindles engage fixed abutments 25 for determining the position of the mandrel after piercing the billet, which mandrel then co-operates with the die throat for forming a tube. If it is desired for the mandrel to move forwardly with the extruded tube, the abutments 25 are rotated through 90 degrees by handles 41 so that the stop 42 can pass through. In another embodiment, Figs. 8-12 (not shown), a single adjusting spindle is used. In a further embodiment, Fig. 15 (not shown), the mandrel operating cylinder is disposed behind the main ram cylinder. |
