GB908942A - Improvements in tube-extrusion presses - Google Patents

Abstract

908,942. Extruding; billet-piercing. SCHLOEMANN A.G. Jan. 2, 1961 [Jan. 22, 1960], No. 32/61. Class 83 (4). A tube-extrusion press has a billet-piercing assembly slidable in a main platen 10 carrying the press ram 14 and comprising a mandrel 13 mandrel holder 16 and mandrel holder carrier 18, releasable from one another at 15, 17, a rotatable connecting means 17 between the holder and carrier being accessible through a window aperture 12 in the platen 10 and the holder being withdrawable through this aperture. The mandrel 13 is connected to its holder 16 by a bayonet joint 15 which upon being released permits the mandrel to be withdrawn forwardly, or rearwardly through the window 12. Connecting means 17 comprises a longitudinally split coupling 20, Fig. 4, having a right-hand thread 22 engaging a spigot 24 of the carrier 18 and a left-hand thread 23 engaging the mandrel holder 16. The spigot and holder are located by a centering spigot 25 and the two coupling halves are connected by screws passing through holes 21. After securing these screws, the coupling is rotated whilst the parts 16, 18 are held stationary, for pressing together their adjacent end faces. A frangible portion 26 fractures upon excessive load being applied to the mandrel. Carrier 18 slides along guides 19 in the platen 10. In another form of coupling, Fig. 5, the mandrel holder 16a has a collar 28 with bayonet teeth 29 co-operating with a longitudinally-slotted sleeve 31 rotatable by a ring 34. The sleeve is located in the carrier 18 by a threaded muff 36 which, after securing the bayonet connection, is rotated to press the collar 28 against a pressure plate 27. Platen 10 has window apertures 12 on both sides and is advanced and retracted along inclined guides on the press bed by fluid pressure cylinders 8, 11, Fig. 1 (not shown). The press has a billet container movable axially along guides on the press bed by fluid pressure cylinders 9a, Fig. 1 (not shown).