Abstract: A punch assembly for punching a workpiece comprising a unitary stripper spring assembly that can be adjustably fastened to a punch. The unitary stripper spring assembly includes a threaded head which engages a threaded end of the punch so the effective length of the punch can be varied after sharpening by simply turning the unitary stripper spring assembly relative to the punch. The punch is fastened to the unitary stripper spring assembly only at the head. The unitary stripper spring assembly further includes a washer, and a telescopic retainer enclosed in a stripper spring between the head and the washer. The telescopic retainer responds to the force exerted on the punch assembly by the ram of a punching device by contracting during the punching stroke. After the punching stroke the stripper spring expands to strip the punch from the workpiece and the stripper spring assembly returns to its normal position.

Abstract: A punch assembly including a punch member having first and second ends, a punching end on the first end of the punch member, an adjustable head on the second end of the punch member, a shoulder on the punch member intermediate the first and second ends, a punch retainer member including a shoulder engaging portion adjacent the shoulder for effectively engaging the shoulder, a stripper spring between the punch retainer member and the adjustable head, retainer shims between the shoulder engaging portion and the shoulder, and a counterbore in the punch retainer member for receiving the retainer shims, the counterbore being of a diameter which is substantially the same as the outer diameter of the retainer shims. By the use of the retainer shims, the distance between a reference point on the retainer member and the end of the punch may be maintained the same even after sharpening, with the adjustable head being adjustable to maintain the overall length of the punch assembly the same after sharpening.

Abstract: A press frame includes upper and lower arm portions forming a recess therebetween for receiving a workpiece that is supported by a worktable mounted on the lower arm portion. A ram housing is supported at the front of the upper arm portion and is provided with a ram punch connected to a power source for reciprocating the ram toward and away from the worktable. A swing arm is connected to the upper arm portion in the recess of the press frame by a vertical shaft and is arranged to pivot in a horizontal plane with respect to the upper arm portion with the shaft. A tool holder is releasably engaged to the end of the swing arm by a locking device and is provided with a vertical bore for receiving a punch tool.