Abstract: In a progressive die for punch press operations in which a strip of material is fed into the press and sequential operations are conducted on the strip including the separation of parts from the strip. The die is provided with a construction which forms an integral carrier tab between the parts to be separated. In the embodiment ilustrated, the operation is the manufacture of rotor and stator laminations for a dynamoelectric machine. The strip of material is fed into the press in which the die is mounted, and the respective rotor and stator laminations are formed in a series of workstations within the die. The improvement in the die construction is a punch station for substantially but not completely separating the rotor lamination from the strip. Thereafter, additional operations are constructed on the strip, the rotor lamination being completely separated at a subsequent workstation.

Abstract: A punch press die (D) is used to construct rotor laminations (RL) and stator laminations (SL) for a dynamoelectric machine (1). A cavity (17) is formed in the die for a punch (15) to travel through and stamp a slot (5) in a strip (3) of material. Opposing side walls (21A, 21B) of the die form the cavity and each side wall has a longitudinal groove (25A, 25B). Each groove is inclined across the face of the wall from one end to the other, the grooves being inclined in opposite directions. In the preferred embodiment, the grooves are oriented about the center-lines of their respective side walls and have a co-planar point (MP) mid-way along their length. Material clinging to the striking face (24) of the punch (115) as it moves through the cavity tends to expand into the grooves and is drawn off from the face of the punch.