| 摘要 |
<p>The invention is directed to a press having a crown member and a base member with support and tiedown means for maintaining the crown member at an operative predetermined work station relative to the base member, and operative press ram means operating between the crown and base means in direct or offset loading position on a workpiece, characterized in that the support and tiedown means comprises hollow columns characterized by greater resistance to the bending forces induced by offset loading than support and tiedown means comprised of solid columns composed of the same kind and amount of material as the hollow columns. These columns furthermore may comprise pressure fluid-actuated cylinders having cooperating pistons and piston rods. By rigidly affixing the base of these cylinders to one of the crown and base members and the free ends of the piston rods to the other, actuation of the piston rods to the outward throw or extended position moves the crown member away from the base member, and actuation to the inward throw or retracted position causes it to move toward the base member and, when so fully actuated, holds the crown member immovably at the predetermined work station. The hollow cylinders should optionally have a relative large length to breadth ratio and a relatively large bore.</p> |
