GB961283A - Improvements in presses or like machine tools - Google Patents

Abstract

961,283. Angular bending; shearing; presses. V. BIANCHI. May 14, 1963 [May 14, 1962], No. 19095/63. Headings B3E, B3H and B3W. A press comprises a fixed frame, a toolsupporting bed mounted for movement towards and away from a fixed tool, a doubleacting jack secured to the frame, and a plurality of connecting rods pivotally mounted on the frame, the ends of the connecting rods being connected to the jack and to spaced portions of the tool-supporting bed whereby reciprocation of the jack causes movement of the toolsupporting bed in a direction such that it remains parallel with its original position. A movable bending blade 1 of a press brake, having a fixed counter blade 2, is supported on a member 5 carried by side members 6 guided for vertical movement. The blade 1 is lowered and raised by a double-acting hydraulic jack 30, a piston 23 of which is connected by levers 16, pivoted at 17 to the fixed press frame, to the side members 6. The piston 23 is raised, to lower the blade 1, by oil delivered under pressure through a duct 34 to bear on that part of the face of the piston 23 surrounding a fixed stem member 28 and, through a duct 35 in the piston 23, on the end of an internal chamber 26 of the piston 23. The piston 23 is lowered, to raise the blade 1, by pressure oil through a duct 32, 31, 33, bearing on the lower annular surface of the chamber 26 surrounding the stem 28, the thrust on the piston 23 being thus much smaller than the previous upward thrust on the piston. The bending blade 1 may be replaced by a shear blade and a bending anvil 2 by a shear counter blade. Connecting rods disposed radially about the drive piston to distribute and balance forces applied over the surface of a platen may be used in a platen press.