TWO STAGE PUNCH PRESS ACTUATOR WITH OUTPUT DRIVE SHAFT POSITION SENSING

摘要

A press for forming a workpiece (27) with a tool set includes an actuator assembly carrying a movable half or punch (14) of the tooling set and having a two phase operation. In the first phase the actuator provides relatively low force in moving the punch (14) to an intermediate position in close proximity to the workpiece (27). A sensor (25) detects the position of the punch (14), and when the punch (14) reaches the intermediate position provides a continue signal. The second phase of actuator operation is conditioned on occurrence of the continue signal, and uses normal high force to press the movable tooling half (14) against the workpiece (27) to complete the operation. The low force first phase allows obstructions of any kind to stop movement of the punch during the first phase before high force applied to the actuator may cause damage or injury to the obstruction. In a preferred embodiment, the actuator assembly has hydraulic operation.