GB781737A - Method and means for operating metal extrusion presses - Google Patents

Abstract

781,737. Extruding. LORANT, H., and LOEWY ENGINEERING CO., Ltd. Aug. 3, 1955, No. 22248/55. Class 83 (4). In the extrusion of metal billets wherein, after the extrusion, a discard D and a shell S, Fig. 3, remain in the container bore 13, the discard and shell are removed by moving the die 14 out of alignment with the container bore so as to leave a discharge space 24 between the container 12 and the fixed platen 10 of the press, Fig. 4 (not shown), whilst the front end of the container is positively supported against the platen 10 by a spacing member or members, and ejecting the discard and shell from the container bore into said space and out of the press. The die 14 is mounted on a die carrier 15 slidable transversely along the guides 18, Fig. 1, on the platen 10. The spacing member or members preferably comprise part of the carrier 15 or an extension thereof. In the extrusion of tubes, Fig. 1, the billet B is first pierced by a mandrel 21 and is then extruded through the annular die orifice by a pressing stem 19 having a pressing disc 20 of smaller diameter than the container bore 13 so as to leave in the. container bore a thin shell S. When billets of metals such as brass or copper are extruded at elevated temperatures, oxides are present at the surface of the billet and these oxides remain in the shell and are not extruded. After extrusion the container 12 is retracted, Fig. 3, the die carrier is moved transversely to the position of Fig. 4 (not shown), and the discard D together with the disc 20 is removed from the container bore by the stem 19, the discard being sheared from the shell S. Thereafter a larger disc 27, Fig. 5 (not shown), is placed on the end of the stem 19 and the latter is operated to remove the shell S from the bore into the space 24. Alternatively the discard and shell together with the disc 20 may be removed as a unit. In another embodiment, Fig. 8, the carrier 15b has an aperture 24b closed at one end by a disc 26 to provide an ejection space for the discard and shell, both of which may be removed as a unit by a disc 27 on the end of the stem 19 which presses the discard against the plate 26 and crushes the shell until it is disposed entirely within the aperture, Fig. 9 (not shown). The bottom of the aperture is closed by a flap 28, Fig. 10 (not shown) when the carrier is in the position shown in Fig. 8, but when the die 14 is returned into alignment with the container bore the flap opens automatically to allow discharge of the discard and shell. In this embodiment the discard and the shell may alternatively be ejected separately. The die carrier may be rotatable instead of slidable. Specification 549,880 is referred to.