Abstract: A hydraulic-control system for a hydraulic press utilizes a main power unit consisting of a pump and a flywheel which delivers the energy necessary for a working stroke to at least one cylinder of the press. An auxiliary power unit consisting of an electric motor and another pump driven thereby is connected to the hydraulic network to drive the first mentioned pump as a motor and rotate the flywheel to increase the energy stored therein.

Abstract: A spindle press in which a lubricant is displaced by relative movement of the threaded spindle and the ram displaced thereby, at least on a return stroke of the ram effected by a fluid operated jack. According to the invention, the press is provided with a control piston which blocks the lubricant flow as the ram approaches a deadpoint position at the end of its return stroke so as to enable the lubricant trapped between the spindle and the ram to damp the end of the return stroke.

Abstract: A method of and apparatus for the bending of metal-sheet section comprises a bending saddle engaging the section at two spaced-apart points and a bending anvil or support engaging the workpiece at two other points disposed outwardly of the first two points. The bending saddle is pressed toward the anvil so that the sheet bends substantially uniformly between the two bearing points of the saddle and the two support points of the anvil with substantially equal bending force components equidistant from the center between the support points. After each bending stroke of the saddle, the workpiece is advanced by an increment less than the length of the uniformly bent section between the two saddle bearing points.

Abstract: A press frame, comprising an upper or head plate, a lower or bed plate and a plurality of posts fitted between the head plate and bed plate of the frame, is provided with tension member, e.g. cables or bands, extending around the frame and lying in successive vertical planes spaced apart horizontally along the frame. According to the invention, the cables or bands, which are slung around the head and bed of the frame and have a U-shaped pattern as they pass therearound, are alternately offset horizontally to one side and to the other so that the tension cross sections within the cables or bands in the respective planes are likewise offset alternately from side to side. The tension elements have their ends connected to stressing units alternately on one side and the other of the press and lying in chambers formed in the posts. The units interconnect ends of the outer tension elements in each chamber.

Abstract: A screw press comprising a flywheel rotatable continuously in one direction and a pneumatically operated coupling, selectively operable to couple the flywheel to the screw for a working stroke, wherein the coupling has a pressure chamber supplied by way of a one-way valve and dischargeable by the action of an inertial mass which rotates with the screw during its working stroke and inertially relative to the screw at the end of the working stroke to open a discharge orifice of the pressure chamber. A valve piston is moveable axially of the screw in a cylindrical recess, serving as an input chamber for supply air, which valve piston projects into a second chamber, connected to the atmosphere and having an opening, coverable by the valve piston, for supply and discharge of the pressure chamber.

Abstract: An apparatus for the external calibration (sizing) of tubular elements such as longitudinally welded large-diameter pipes, comprises an outer support ring, a wedging mechanism connected to this ring, and a plurality of pipe-engaging calibrating elements which are closed against the external surface of the pipe as the latter is drawn through the apparatus to impart the desired external diameter thereto. According to the invention, the outer support ring forms a cylinder within which an annular piston is displaceable, the piston being formed with surfaces inclined to the axis of the pipe and acting directly or indirectly upon the pipe-engaging elements.

Abstract: A hydraulic press, especially a sheet-bending press which has a lower beam provided with a press table and a vertically displaceable upper beam having a plunger or ram. The two beams are connected by columns which are formed as piston-and-cylinder arrangements to the upper and lower beams, respectively, by compensating bearings which permit an inclined orientation of the upper beam relative to a normal horizontal position without interfering with the force-transmitting characteristics. The compensating bearings are constituted as transverse bearings having bearing axes which are perpendicular to the longitudinal dimension of the beam and through which the piston-cylinder arrangement is pivotally connected to the upper and lower beams.

Abstract: A succession of rectangular mats, consisting essentially of asbestos fibers or other filamentary material held together by a wet hydraulic binder such as cement, are conveyed by a series of trays through the gap between a pair of horizontal platens of a press. The upper platen carries a die for trimming the edges of a mat to be compacted, with the tray acting as an anvil. The trays are linked near their leading ends with two parallel, endless conveyor chains and have their trailing ends supported by rollers on rails which parallel the upper and lower runs of the chains and which form ramps for guiding these rollers onto the lower level downstream of the press and onto the upper level upstream of the press whereby each tray runs horizontally through the press between a loading and an unloading station.

Abstract: A sheet-metal workpiece is clamped in a bending press with its one side lying on a pair of bending beams spaced apart in a transport direction and with a bending roller pressing in a bending direction transverse to the transport direction against the other side of the workpiece between the beams. A first feeler roller is pressed against the one side of the workpiece at the first location opposite the bending roller with a force sufficient to relieve substantially all of the elastic deformation in the workpiece. The workpiece is contacted to each side of the first feeler roller with second and third feeler rollers spaced apart in the transport direction and the spacing between the first feeler roller and the second and third feeler rollers in the bending direction is then measured to ascertain the permanent bend (plastic deformation) of the workpiece.