Abstract: A punch press for cutting windows in a ball cage. The ball cage is held in an established position. A first press assembly includes a first frame member and a punch assembly on a first surface of the cage, for cutting a portion of the cage. A second press assembly includes a second frame member, a cutting bed for supporting a second surface of the cage, said first and second surfaces being opposite surfaces of the cage, around the portion to be cut by the punch assembly. It also includes a counterpunch for opposing the punch assembly on the second surface. Pressure is applied to the second press assembly toward the punch assembly.

Abstract: A cylinder (3) has a piston rod (21) with a uniform diameter and is connected to a hydraulic tank (7) by way of a relay valve (4). A first end (27) of a piston rod (21) is directly coupled to a traverse rod (28) carrying a thread guide (29). A second end (31) of piston rod (21) is coupled to an iron core (32) of an inductive position sensor (5), which generates a signal (y) for the actual position of piston rod (21). A shaft (35) for a wound twist-yarn bobbin (37) is equipped with a tachometer generator (38), which generates a signal (v) proportional to the number of revolutions. Output signals (y,v) of position sensor (5) and tachometer generator (38) are applied to an electronic control device (6) which, in accordance with these signals (y,v) and other, digital, adjustable stroke parameters, supplies an analog control signal (s) to relay valve (4).

Abstract: A device for precluding improper operation of a stamping press including a control cylinder the piston of which is impinged on one side by a pressure medium and on the other side by a pressure medium having a variable constant pressure. Electrical switch elements are utilized to prevent the stamping operation from progressing unless preset conditions exist.