Abstract: A press brake is comprised of a frame having a bed secured thereto with a ram displaceable to and away from the bed whereby to form metal sheets positioned on the bed. The ram is secured to a hydraulic piston through opposed symmetrical linkage assemblies. Each linkage assembly is connected adjacent opposed ends of the ram and includes a lever member pivotally secured to the frame by an anchor pin pivot connection. A link arm interconnects the lever member to the ram by pivot pin connections adjacent opposed ends of the link arm. An interconnecting bar interconnects the lever member of each linkage assembly together by a further pivot pin connection adjacent opposed ends of the interconnecting bar.

Abstract: Each of the metallic units has a concave portion bounded by a peripheral edge which has a predetermined shape. The apparatus includes an upper member and a lower member and a tool is adapted to be mounted on the upper or lower member. The tool comprises a wall-like structure having a bottom edge which defines a shape corresponding with the predetermined shape. The upper member and lower member are arranged to be movable relative one to the other, and a workpiece is placed between the two members and the members are brought together until the tool is clamped abuts the workpiece so that the tool and workpiece are clamped together in airtight engagement. Air under pressure is applied under the workpiece to form the workpiece into a concave shape.

Abstract: Two shearing blades disposed along two lines which intersect each other are carried on the bottom edges of two adjacent walls of a four-sided ram structure. The ram is supported at four points whereby to provide greater stability. The workpiece is carried on the aligned top surfaces of a fixed bed and a movable carriage. The movable carriage is movable in a first direction. Finger grippers, joined by a connecting bar, are movable in slots along the top surface of the movable carriage in a second direction. Thus, the workpiece is moved in the first direction by movement of the movable carriage and in the second direction by movement of the finger grippers. The workpiece may be precisely and accurately positioned under the shearing blades making use of sensors in each of the finger grippers and a lateral sensors in each of the finger grippers and a lateral sensor at the end of the movable carriage.

Abstract: Two shearing blades disposed along two lines which intersect each other are carried on the bottom edges of two adjacent walls of a four-sided ram structure. The ram is supported at four points whereby to provide greater stability. The workpiece is carried on the aligned top surfaces of a fixed bed and a movable carriage. The movable carriages is movable in a first direction. Finger grippers, joined by a connecting bar, are movable in slots along the top surface of the movable carriage in a second direction. Thus, the workpiece is moved in the first direction by movement of the movable carriage and in the second direction by movement of the finger grippers. The workpiece may be precisely and accurately positioned under the shearing blades making use of sensors in each of the finger grippers and a lateral sensor at the end of the movable carriage.