Patent GB-439071-A (GB)
Title: Improvements in or relating to extrusion presses for the manufacture of metal tubes
IPC: B21C23/21
Filed: 1934-10-02
Abstract: 439,071. Squirting. MASCHINENFABRIK MEER AKT.-GES., 29, Karmannstrasse, Gladbach, Munich, WEFING, A., 26, Breddestrasse, Witten-on-Ruhr, and SINGER, F., and LIEBERGELD, A., 70, Klingenhofstrasse, Nuremberg, all in Germany. Oct. 2, 1934, No. 28159. [Class 83 (iv)] Billet - piercing.- A mechanical tube extrusion press of the upright type has driving means, carried in the foot of the press, for driving a matrix carrier for extrusion of the billet. A press comprises a cross-head 21, Fig. 6, carrying a piston 22, over which is slidable a member 24 providing a fluid chamber 46 and supporting a piercing mandrel 30, relative motion being limited by flanges 23, 25. The support 27 for the extrusion plunger 31 is slidable in guides 28, 29 in the press frame and is suspended from a cross-head 33 by rods 32, a piston 34 extending from the cross-head into a cylinder 35 formed in the parts 21, 22. The container 18 for the billet a, and the die 19 are carried on a member 17 reciprocated by cranks 8, 9. A discharge channel for the extruded tube is pivotally supported by bolts 13, 14. The chamber 35 is initially connected to a pressure supply by a valve 43, Fig. 1, while the chamber 46 is connected to a source of low pressure by a valve 50 to raise the press members 27, 24, and 22 to their upper position. The block a is then inserted, and the chamber 35 connected to exhaust whereupon the members are lowered until the stops 39 contact the cross-head 21, the shoulders 23, 25 engage, and the space 46 is filled with low-pressure water. The valve 50 is operated to disconnect the chamber 46 from either pressure supply, and the crank drive is set in motion to pierce and then extrude the billet. The tools are returned to the original upper position by actuation of the valves 43, 50, and a ram 57, Fig. 7<a>, on the member 27 is swung into position and actuates a chisel 61 upon the admission of high pressure to the chamber 46 to sever the residue. The valves 43, 50 may be operated manually or mechanically from the crank drive. A modified press comprises cams 67, 68, Fig. 9, on the shafts 2, 3, which engage followers 69, 71, on frames 74 connected by rods 83, 84 to a cross-head 87, which carries a piston 88 engaging within a cylinder 63 integral with the support 24 for the piercing mandrel 30. The bore 100 communicates with a pipe 103, Fig. 11, having a safety valve at its upper end and a valve 104 at its lower end communicating with a pipe 106. The space 46 communicates with the pipe 106 and the latter may communicate through a valve 114 with a source of pressure 119. The members being in their raised positions the crank drive moves the carrier 17 downwardly, the cams simultaneously lowering the cross-head 88 and the mandrelsupport 24, both valves being closed. The extruding plunger support 27 is suspended from a pivoted arm 94 which in the raised position engages a stop 97, the support 27 thus descending with greater speed than that of the member 24, until the shoulders 64, 66 contact. The tendency for the formation of a vacuum in the space 46 causes the valve 114 to open, and pressure fluid to flow in from the vessel 119. On further rotation of the cranks, the billet container and die are raised to pierce and extrude the billet. At the end of the extrusion operation which occurs before the stroke is completed, the valve 114 is positively opened by a cam-headed lever 129 to permit water to discharge from the space 46 into the vessel 119 and the stamp and mandrel to be raised by the member 17. The valve 104 is opened at the same time, or the rollers 72 are at this time free from engagement with the cams 68. The support 17 is then lowered, the support 27 following it under its weight to strip the tube and then rising with increased speed when the members 94, 97, contact. In a further modification, the mandrel-carrier 24 is suspended from a rod 143 of a piston 144, and the extrusion plunger support 27 is pivoted to members 150 pivoted to the forked end of a lever 149, which is pivoted to a bracket 142 integral with the support 24. A valve 170 is opened when a follower 186 rides over a cam surface 185 on the gear 6. A rod 161 is reciprocated by a member 163 attached to the gear 6 and engaging in a slot at the lower end of the rod. A cam member 172 is reciprocated with the rod to control valves 166, 167 through linkwork, and a piston 158 is carried on the upper end of the rod. A valve 148 is initially rotated to equalize pressure above and below the piston 144, and the mandrel carrier 24 descends under gravity with a speed controlled by a throttle in the pipe 146, valve 166 being open and 167, 170 closed. Valve 170 opens to permit filling water to flow through the pipe 169 into the space 141. The carrier 27 advances ahead of the carrier 24, the motion then being stopped by actuation of the valve 148. The relative motion of the members 24, 27 is limited by a stop 154. The crank drive is then initiated, raising the member 17 and the piston 158, the latter lowering the perforating mandrel, while the member 27 is brought to rest on the block. After substantially complete piercing, the member 172 causes valve 166 to close and valve 167 to open, the member 17 rising to complete the extrusion after which the valves are reversed, the valve 170 also being opened by the cam surface 185. The cock 148 is returned to raise the piston 144 and the mandrel support, the member 27 first descending but finally rising to the initial position. The approach movement as well as the piercing stroke of the member 24 may be effected by a modified piston and cylinder 158, 156.