Abstract: A roller hold down is designed to restrain parts being cut from a stack of flat sheets. The roller hold down eliminates the need for secondary fastening means to restrain the parts during the cutting operation. The parts are restrained in position on a flat worktable by a pair of cylindrical rollers adjacent the cutter which force the parts against the table. By use of the roller hold down, the restraining force applied through the rollers follows the excursions of the cutter and is applied near the cutter where the force is the most effective.

Abstract: A machine for drilling and routing of printed circuit boards comprises a support mechanism for supporting a stack of superimposed boards in a support plane and for moving the stack of boards in a first predetermined direction parallel to the support plane. A tool spindle is disposed above the stack of boards and is movable in a second direction parallel to the support plane and perpendicular to the first direction, so that the positions of the holes to be drilled in the PC-boards can be determined in a coordinate system having the first and second directions as its X-axis and Y-axis respectively. For holding the stack of PC-boards pressed together during the drilling or routing operation, the machine comprises press rollers, which exert a pressure force upon the stack of PC-boards towards the support mechanism. The press rollers are arranged on both sides of the tool spindle with their axes of rotation parallel to the direction in which the tool spindle can be moved, i.e. the Y-direction.

Abstract: A clamping apparatus attachable to a rail for supporting a portable machine tool therefrom including exchangeable and formed clamping blocks with pre-set adjustment members to match points on the web contour between the base and head of all sizes of rail, and to accurately align and securely lock the machine tool into its proper working position relative to the rail without any location against parts of the rail subject to wear.