Press guide structure

Abstract

The present invention relates to a mechanical press, and in particular to a guiding arrangement for the reciprocating slide of such a press. The press comprises a crown and bed and a plurality of vertical uprights connecting the crown and bed. A plurality of guideposts are rigidly connected to the crown and depend downwardly therefrom, the guideposts being parallel to each other and substantially perpendicular to the plane of the bed. The guideposts each have free ends which are unsupported and terminate short of the bed of the press so that the parallelism of the guidepins is determined solely by their connection to the crown. In order to counteract the non-vertical forces exerted on the slide by the connection arms, which tend to cause the slide to tilt about a horizontal axis perpendicular to the axis of the crankshaft, bearings are mounted between the connection assembly and the crown. The bearings exert restraining forces on the connection assembly in a direction perpendicular to the axis of reciprocation of the slide and along lines which intersect the axis of rotation of the wrist pins. In a preferred embodiment of the invention, the bearings are hydrostatic bearings interposed between the connection pistons and their respective cylinders, although hydrodynamic or roller bearings could be used. By this arrangement, the slide and connection arm assembly is accurately guided by elements which are connected only to the crown portion of the press so that the frame of reference for alignment is more localized than in prior art presses wherein tie rods or guideposts are also connected to the bed.