A punching device includes a body, a drive unit connected to an upper part of the body, and a cam block that moves in a horizontal direction in the interior of the body under a driving action of the drive unit. A second rotating roller, which is connected to a rod, is inserted in a second cam groove of the cam block. The second cam groove includes first and second groove portions inclined at predetermined angles with respect to the direction of movement of the cam block, such that when the rod descends downwardly toward a workpiece, a second rotating roller moves from the second groove portion to the first groove portion having a smaller angle of inclination, whereby the driving force transmitted to the rod is boosted in power.

The invention relates to a precision blanking press including a top, a base and tie rods and columns that operatively connect the top and the base. The precision blanking press has a press frame with a high stiffness, low mass and simple design, the press allowing the transfer of higher cutting forces during fine blanking while safely eliminating axial play between adjustment elements and at the same time improving the operational safety.

A pneumatic chamber 20 is configured to include a first pneumatic chamber 21 pressurizing a first piston 11 and a second pneumatic chamber 22 pressurizing a second piston 12. The first pneumatic chamber 21 communicates with the second pneumatic chamber 22. The hydraulic pressure generating unit 55 is internally provided with a hydraulic chamber 30, and the hydraulic chamber 30 is configured to have a first hydraulic chamber 31 pressurized by the first pneumatic chamber 21 via the first piston 11 and a second hydraulic chamber 32 pressurized by the second pneumatic chamber 22 via the second piston 12. The hydraulic pressure generating unit 55 is movable in a thrust direction in a cylinder 2, and the second hydraulic chamber 32 has a function of fixing the moving hydraulic pressure generating unit 55 in the cylinder 2 by causing a thin portion 15 to be elastically deformed in a radial direction due to hydraulic pressure. The first hydraulic chamber 31 outputs hydraulic pressure of the first hydraulic chamber 31, which is increased by the fixing, to an output rod 7.

Punch jaws are provided and are configured to punch holes and/or recesses in parts made of sheet metal. The punch jaws include first and second jaws pivotally connected to each other around a pivoting axis to pivot in a pivoting plane. A work region is formed by a punch ram on the first pivoting jaw and a punch opening on the second pivoting jaw. The punch ram carries a punch sleeve having a punch edge on its circumference. The punch sleeve moves in a side view, in which the pivoting axis is punctiform, along a circular line, a center point of which is formed by the pivoting axis, during its pivoting motion. The punch sleeve is introduced into the punch opening in a side view initially penetrates the punch opening with a front region the punch edge referred to the pivoting direction. The front region is in this side view formed on the side of the pivoting axis of the circular line with respect to a pivoting circle, along which the punch sleeve moves.

The present invention aims to provide a manufacturing device for heat exchanger fins that is capable of adjusting for differences between a number of punches and a number of through-holes or cutaway portions in an actual product without causing a metal strip to sag or having punches punch the same positions twice. As a solution, a mold (46) is provided with a plurality of punches (75) and a plurality of dies (76) that form a plurality of through-holes or cutaway portions along a conveying direction of a metal strip (49) and also includes a feeding apparatus (50) that feeds the formed plurality of through-holes or cutaway portions in the feeding direction in a single feeding operation, and a cutoff device (60) that cuts the metal strip (49) into predetermined lengths has an equal number of cutoff punches (68) to a number of the punches and dies disposed along the conveying direction of the metal strip (49), includes a plurality of cutoff punch driving units (72) that respectively and individually operate the cutoff punches (68), and also includes a control unit (80) that controls each of the cutoff punch driving units (72).

A punch apparatus includes a drive unit and a driving force transmission mechanism that transmits a driving force output by the drive unit to a rod. In the driving force transmission mechanism, a cam groove is formed in a cam block connected to a piston rod, and a rotating roller, which is pivotally supported on a displacement body connected to the rod, is inserted through the cam groove. The cam groove has a first groove portion and a second groove portion, which are inclined at predetermined angles of inclination with respect to the displacement direction of the cam block. When the rod is made to descend toward the workpiece, the rotating roller moves from the second groove portion into the first groove portion, which has a small angle of inclination, whereby the driving force transmitted to the rod is boosted.

A press machine includes at least one actuator and at least one linkage to open and close a ram. Another aspect employs a sheet metal-working punch mounted to the ram. A fluid-powered piston drives a carriage coupled to a linkage in another aspect of the present machine. In still another aspect, at least a majority of an actuator is located externally to an outside surface of a stationary structure within which a ram is located. Yet a further aspect both opens and closes a ram with a unidirection movement of an actuator.

A hand-held knockout driver includes a main housing having a handle portion, a motor positioned within the main housing, a pump assembly driven by the motor, and a secondary housing coupled to the main housing and defining a bore therein. The hand-held knockout driver also includes a working piston moveable within the bore from a rest position to an actuated position to define a piston throw distance therebetween. The hand-held knockout driver also includes a draw stud coupled to the working piston, a die coupled to the secondary housing, and a punch coupled to the draw stud opposite the working piston for movement therewith relative to the die. The die has a depth greater than the piston throw distance.

A spring assembly is provided which decreases the fatigue and wear on the springs of the assembly. The spring assembly includes upper and lower pistons separated by a substantially incompressible fluid. The lower piston is attached to one or more springs. The surface area of the upper surface of the lower piston is greater than the surface area of the lower surface of the upper piston. As such, the springs are deflected by a distance less than the distance traveled by the upper piston. By decreasing the length the springs are compressed, the springs are subject to less fatigue and wear. As a result, the life span of the springs is increased and the maintenance required of the spring assembly is minimized relative to that of typical spring assemblies.

A sheet metal working machine includes a hydraulic drive system to drive a plurality of working tools in a separate and independent manner. The hydraulic drive system includes a plurality of hydraulic cylinders provided with pistons defining thrust chambers and return chambers and associated with corresponding working tools, a reversible first pump connected to the thrust chambers and arranged to send fluid to, or to suck fluid from, at least one of the thrust chambers so as to move the respective piston and the working tool associated therewith, a plurality of valves interposed between the first pump and the thrust chambers of the respective hydraulic cylinders and activable to connect the first pump to the thrust chambers; a hydraulic accumulator connected to the return chambers and arranged for maintaining fluid at a defined preload pressure therein.