Milling tool for turret punch press

Abstract

An air powered milling tool supported in the upper turret of a turret punch press is cycled simultaneously with a hydraulically- or mechanically-powered punch press ram in a multiple-stage cycle to perform a milling operation on a sheet material workpiece retained between the upper and lower turrets of the punch press. The air-powered tool, which includes a punch head in coaxial alignment with a guide sleeve, drives an end mill which is contained within and is coaxially extendible through the guide sleeve toward the workpiece to perform a machining operation thereon. Hold-down bearings disposed at the end of the guide sleeve engage with the workpiece at a local region thereof. A spring-biased lifter disposed in the upper turret is engagable with the guide sleeve. In operation, the punch press striker impacts the punch head of the milling tool, urging the milling tool and air motor in the direction of the sheet material. As the tool descends, the milling tool extends from the guide sleeve and impacts the sheet material. Simultaneously, a compressed air charge or steady state air flow is flowed through the striker and into the milling tool body and is delivered to the air motor which drives the milling tool in the desired machining operation. Subsequent to the completed machining operation, the striker is reciprocated to its idle position, thereby enabling the lifter and the hold-down spring to return the punch head and guide sleeve, respectively, to their initial idle positions. Overall system operation is computer controlled.