| 摘要 |
<p>Tubular workpieces with variable transverse section e.g. drilling shanks are formed in an horizontal hydraulic press in which the mandrel which determines the form of the internal wall of the workpiece passes through the die so as to be connected to a rod assembled with drive pistons which move the rod in the drawing direction. The press has at least two mobile abutments of which one adjusts the working pos'n. of the mandrel in relation to the die and limits the displacement of the rod and mandrel in the drawing direction. Esp. the rod carrying the mandrel has supplementary drive pistons which move the rod in the direction opposite the drawing direction and a second mobile abutment limits displacement of rod and mandrel in the former direction when the stock is displaced.</p> |
