A part of kinetic energy during lowering of a slide of a press machine is converted into oil hydraulic energy by a first oil hydraulic cylinder, and the converted oil hydraulic energy (hydraulic oil having boosted first system pressure) is stored in a first accumulator. The hydraulic oil having the first system pressure stored in the first accumulator is discharged in knockout process, a second oil hydraulic cylinder that functions as a knockout cylinder is raised to perform knockout operation of a product worked by the press machine. Consequently, it is possible to perform knockout operation without using a dedicated driving source such as an oil pressure source and an air pressure source, and provide a low-cost hydraulic knockout device.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

An actuator device includes two drive units for an actuator output element. The first drive unit has a first piston chamber and a first piston displaceable therein and also first hydraulic means for displacing the piston. The second drive unit has a second piston chamber and a second piston displaceable therein and also second hydraulic or pneumatic means for displacing the piston. The second piston is joined to the actuator output element for conjoint movement therewith and can be coupled to the first piston for thrust, so that the second piston is displaceable in an outward direction by the first piston. The first drive unit is configured for a larger thrust force than the second drive unit, while the second drive unit is designed for a greater stroke speed than the first drive unit.

A forging and inclined window hole punching composite die includes an upper die holder, a connection sleeve, an upper die sliding sleeve, a pressure plate, inclined window puncher pins, a center puncher pin, first connection screw rods, first springs, second connection screw rods, second springs, hydraulic assistant systems, a lower die and a bottom plate. Bottom surface of the pressure plate of the composite die is a plane to avoid deformation of a front molding surface. Hydraulic power is added to the inclined window puncher pins to increase the pressure for punching inclined holes, avoid quality problems and increase a demolding force. A multi-split synchronous hydraulic device may well realize synchronization of the plurality of inclined window puncher pins.

A pilot assembly and method has a cylindrical pilot body with a tapered outer end, a grooved inner end, and a central portion with at least one inwardly curved side wall relief, as well as internally mounted reciprocating ejector pins with outer ends that protrude through holes in the outer body end to strip stock from the pilot. A spring has its outer end mounted in the groove in the outer body end, and an inner end attached to the inner body end in a pre-tensed condition. A cap screw has an enlarged head that has at least a portion thereof fit into the pilot sidewall relief, and a threaded shank that anchors the pilot in an associated die member.

A pilot assembly and method has a cylindrical pilot body with a tapered outer end, a grooved inner end, and a central portion with at least one inwardly curved side wall relief, as well as internally mounted reciprocating ejector pins with outer ends that protrude through holes in the outer body end to strip stock from the pilot. A spring has its outer end mounted in the groove in the outer body end, and an inner end attached to the inner body end in a pre-tensed condition. A cap screw has an enlarged head that has at least a portion thereof fit into the pilot sidewall relief, and a threaded shank that anchors the pilot in an associated die member.

A stamping press for stamping a round blank. A ram movable in a stroke direction and in an opposite return stroke direction carries a first stamping tool. A second stamping tool and a stamping ring are supported on a press framework. The stamping tools and a stamping opening formed by the stamping ring are aligned along a working axis. An ejector device serves to eject a stamped round blank from the ring opening. It comprises an ejector pin supported on an actuating device that is movably coupled with the ram. During a return stroke of the ram the ejector pin can apply a force on the second stamping tool in order to press the round blank out of the stamping ring. In a ram movement in the stroke direction the actuating device departs from the second stamping tool and no ejector pin force is applied on the second stamping tool.

A stock lifter for metal forming dies includes a self-contained assembly. The assembly includes a guide pin that reciprocates within a base. A hardened end cap, which contacts the stock, is attached to the guide pin. A spring is located on the exterior surface of a portion of the base and surrounds the guide pin body. One end of the spring contacts a surface on the cap, while the other end of the spring contacts a surface on the base or an optional mounting flange that is attached above the base. Thus, the stock lifter assembly has a hardened cap for the stock to slide on and a larger, externally mounted spring that provides longer life for the stock lifter. The stock lifter assembly can be made of several different lengths and sizes by using longer or wider guide pins and springs.

An automatic cleaner for a pressing device has a pressing unit that can reciprocate between a pressing position and an apart position. The automatic cleaner includes a separating structure configured to separate a workpiece from the pressing unit; a cleaning member; and a drive mechanism configured to move the separating structure and the cleaning member back and forth, in accordance with movement of the pressing unit. The drive mechanism is configured to make the separating structure drop the workpiece, after being worked, from the pressing unit, and to make the cleaning member clean the pressing unit, in accordance with the movement of the pressing unit.

An automatic cleaner for a pressing device has a pressing unit that can reciprocate between a pressing position and an apart position. The automatic cleaner includes a separating structure configured to separate a workpiece from the pressing unit; a cleaning member; and a drive mechanism configured to move the separating structure and the cleaning member back and forth, in accordance with movement of the pressing unit. The drive mechanism is configured to make the separating structure drop the workpiece, after being worked, from the pressing unit, and to make the cleaning member clean the pressing unit, in accordance with the movement of the pressing unit.