Patent ID: 8230781

Claim:
A mechanical press for fine blanking, forming and/or stamping of work pieces comprising: a machine frame including a head piece and an O-shaped frame; a fine blanking or forming head provided with an upper tool part that is fastened to the head piece; a ram provided in the O-shaped frame, the ram having a table top to which a lower tool part can be fixed, the ram being actuable in the O-shaped frame along a vertical stroke axis; a toggle mechanism positioned in the O-shaped frame at a location below the ram, the toggle mechanism having a first side and second side, which first and second sides are respectively positioned on first and second sides of the ram, each of the first and second sides of the toggle mechanism comprising: a connecting rod having a substantially equilateral triangle shape, the connecting rod having an upper articulation point at a first triangle corner and a lower articulation point at a second triangle corner; the lower articulation point of the connecting rod being pivotally connected to a first end of a lower articulated arm, the lower articulated arm having a second end that is pivotally connected to a first fixed bearing provided on the O-shaped frame that lies along the vertical stroke axis in which the ram is actuable; the upper articulation point of the connecting rod being pivotally connected to a first end of an upper articulated arm, the upper articulated arm having a second end that is pivotally connected to the ram; the connecting rod connected at a third triangle corner to a gear housed in a second fixed bearing provided on the O-shaped frame; the gear receiving an eccentric shaft having a first end that is connected to a three-phase synchronous motor, wherein the three-phase synchronous motor does not have a flywheel; whereby motor-driven actuation of the eccentric shaft is translated through the gear to the connecting rod, the upper articulating arm, the connecting rod, and the lower articulated arm, to effect movement of the ram along the vertical stroke axis; and when, during motor-driven actuation, the ram is located at an upper dead point of the vertical stroke axis, the upper articulating arm, the connecting rod, and the lower articulated arm attain an effective length that deviates a few degrees from the vertical stroke axis to thereby have a length that substantially similar to a length of the vertical stroke axis; and a computer controller in connection with and controlling of the three-phase synchronous motor on the first side of the toggle mechanism and the three-phase synchronous motor on the second side of the toggle mechanism.