Abstract: A hydraulic press arrangement which includes at least one top cross beam and one bottom cross beam with a press ram, displaceable by means of two cylinder-piston units supplied by at least one pressure medium source, being disposed between the top and bottom cross beams. Each cylinder-piston unit includes a cylinder arranged in the bottom cross beam and in the top cross beam with a piston being guided in each of the cylinders. Two pistons of a mutually associated cylinder-piston unit are connected by way of a piston rod to the press ram. With the arrangement of the cylinder-piston units as well as the controlling of the impingement and venting of cylinder chambers, a relaxation of forces acting on the press frame, due to a subsiding of forces acting in the press working space, is prevented.

Abstract: An arrangement for protecting tools in a hydraulic press against overloading if a foreign object or body is present in a tool space of the hydraulic press. A displacement or travel switch monitors at least a portion of a path of movement of a press ram with a control member providing an output signal during a predetermined movement of the press ram. A control circuit evaluates a sequence of the output signals of the displacement or travel switch and the control member in such a manner that a fault signal is formed when the additional switching device provides an output signal prior to an output signal of the displacement or travel switch. The control member is arranged in a path of force of at least one component of the hydraulic press and is constructed as a signal transducer operating virtually stationarily as a function of pressure.

Abstract: An arrangement for protecting tools in a hydraulic press against overloading if an object is present in a tool space of the hydraulic press. A displacement switch monitors at least a portion of a path of movement of a press ram with an additional switching device providing an output signal during a predetermined movement of the press ram. A control circuit evaluates a sequence of the output signals of the displacement switch and additional switching device in such a manner that a fault signal is formed when the additional switching device provides an output signal prior to an output signal from the displacement switch. The additional switching device may be constructed as a switch element which provides an output signal in dependence upon a pressure or a speed of flow of a pressure medium in a hydraulic circuit.

Abstract: A protection arrangement for a tool set in a hydraulic press in which press, a press ram can be moved by at least one rapid- or fast-stroke cylinder piston unit and at least one working stroke pressure unit in a working stroke direction. The protection arrangement protects the tools from an overloading by a foreign object or body situated in the tool space and includes a displacement or path switch monitoring a portion of the path of movement of the ram and a further switching element which responds during movement of the press ram, as well as a control circuit for evaluating the sequence of response of the displacement or path switch and the switching element in such a way that a fault signal is produced if the switching element responds before the path or displacement switch.

Abstract: A press arrangement which includes a press ram selectively displaceable in a working stroke direction by at least one hydraulically actuated, double-acting cylinder piston unit with an auxiliary drive arrangement being provided for displacing the press ram in an idle stroke preceding a working stroke. The auxiliary drive arrangement bypasses the at least one cylinder piston unit and acts on the press ram. The auxiliary drive arrangement may be constructed as a toothed rack-and-pinion arrangement, a linearly double-acting pressure medium drive, or may include an electric linear motor acting on the press ram.

Abstract: Apparatus for protecting tools of hydraulically operated fine punch presses of the type having a main piston as well as quick-closing pistons for imparting movement to the press ram. Keying pistons are arranged at the ram in series with and extending in the same direction as the quick-closing pistons to form a keying gap, variable in response to resistance pressure applied to the ram movement at or near the closing operation. A safety stop switch is arranged for detecting the keying gap and for effecting a stoppage of the machine in the event the keying gap is below a predetermined amount indicating an impediment in the path of the ram.