Patent ID: 7033155

Claim:
A hydraulic press for compressing metallic powder or the like to form compacts, comprising a die-plate, an upper ram, and at least one lower ram which interact with a die-bore and are operable each by a dual-action hydraulic press cylinder, a limited dead path length being provided for the return stroke in the force path between the press cylinder and the upper ram, in which path the upper ram is not carried along, and a separate pressure generator producing a variable pressure being arranged in parallel with the force path via which a compression force is produced on the upper ram during the dead path length, the separate pressure generator acting on the upper ram through a second force measuring device, a control device which actuates the separate pressure generator if the force measured by the second force measuring device is below a predetermined value or the hydraulic cylinder of the upper ram, respectively, has reached a predetermined position during the return stroke, the position being measured by path measuring means, and a force-path curve being stored in the control means along which the force of the separate pressure generator is acting on the upper ram when the upper ram starts the return stroke.