Abstract: A press machine includes at least one mobile bolster movable with respect to the press machine, a plurality of die assemblies mounted on the mobile bolster and arranged in a row at equal intervals, a plurality of handling bars for transferring a plurality of workpieces successively through the die assemblies, one or more workpiece holders detachably mounted on each of the handling bars for holding the workpieces, feed bars for moving the handling bars, lifting/lower units for vertically moving the feed bars, and handling bar gripping devices for gripping the handling bars. A method of changing the workpiece holders comprises the steps of gripping the handling bars with the handling bar gripping devices, releasing the feed bars from the handling bars, elevating the feed bars beyond the die assemblies with the lifting/lowering units, moving the mobile bolster out of the press machine, and detaching the workpiece holders from the handling bars and replacing the workpiece holders with new workpiece holders.

Abstract: In a system for removing press-formed parts formed in a pressing machine, a loading transfer device is disposed between an ejection position to which a plurality of press-formed parts are simultaneously ejected in parallel from the pressing machine and a loading position established to load the press-formed parts onto each of a plurality of carrier pallets which are on standby in parallel to individually correspond to the plurality of press-formed parts. The loading transfer device comprises a plurality of transfer pallets connected to one another with variable spacings therebetween and reciprocally movable in parallel between the ejection position and the loading position so that the plurality of press-formed parts may be placed onto the individual transfer pallets, and a spacing-varying drive device for varying the spacing between the transfer pallets. During transferring of the press-formed parts by the loading transfer device, the spacing between the press-formed parts is varied.

Abstract: A press machine includes at least one mobile bolster movable with respect to the press machine, a plurality of die assemblies mounted on the mobile bolster and arranged in a row, a plurality of handling bars disposed in retracted positions between the die assemblies and movable, when one pressing cycle is completed, for gripping and transferring a plurality of workpieces successively through the die assemblies, and a plurality of handling bar gripping devices disposed in the retracted positions closely to the opposite sides of the side assemblies.

Abstract: A conveyor in a plastic working machine, wherein lower dies and upper dies for plastic working of a work in collaboration are disposed on a plurality of working stations, respectively, the stations being set at intervals along the direction in which the work is conveyed, arms each having a handling mechanism for holding the work are provided on transfer bars disposed sideway of the working stations for conveying the work in sequence among the working stations, the transfer bars are provided on both sides of each working station, the arms are bridged between both the transfer bars with both the ends borne on both the transfer bars movably back and forth in the conveying direction or fixed to both the transfer bars.

Abstract: A conveyor in a plastic working machine, wherein lower dies and upper dies for plastic working of a work in collaboration are disposed on a plurality of working stations, respectively, the stations being set at intervals along the direction in which the work is conveyed, arms each having a handling mechanism for holding the work are provided on transfer bars disposed sideway of the working stations for conveying the work in sequence among the working stations, the transfer bars are provided on both sides of each working station, the arms are bridged between both the transfer bars with both the ends borne on both the transfer bars movably back and forth in the conveying direction or fixed to both the transfer bars.

Abstract: A conveyor in a plastic working machine, wherein lower dies and upper dies for plastic working of a work in collaboration are disposed on a plurality of working stations, respectively, the stations being set at intervals along the direction in which the work is conveyed, arms each having a handling mechanism for holding the work are provided on transfer bars disposed sideway of the working stations for conveying the work in sequence among the working stations, the transfer bars are provided on both sides of each working station, the arms are bridged between both the transfer bars with both the ends borne on both the transfer bars movably back and forth in the conveying direction or fixed to both the transfer bars.

Abstract: A trimming and piercing apparatus of an extremely high operation efficiency which is capable of trimming and piercing a work simultaneously. The apparatus comprises a fixed die provided with a work mounting surface and a piercing bore opened at the work mounting surface, and a movable die displaceable toward and away from the fixed die. A pair of movable blades and a pair of fixed blades are provided in a spaced opposed relation on the movable die and the fixed die, respectively, so that the movable blades are engageable with said fixed blades when the movable die is moved toward the fixed die. A cam slide having a piercing punch is slidably mounted on the movable die. A cam driver is mounted on the fixed die for driving the cam slide to move along the movable die toward the fixed die to place the piercing punch into fitting engagement with the piercing bore in the fixed die as the movable die is displaced toward the fixed die.