Abstract: A moving web or sheet of material in which an operation is to be performed, such as punching of a hole, is advanced past a pneumatic edge position sensor which is mounted on a carriage for movement transversely toward and away from the edge of the web. The movable carriage also supports the mechanism which is to perform the particular operation (e.g., a hole punching device) and a pneumatic cylinder is connected to the carriage to effect its movement toward or away from the edge of the web to follow any lateral displacement of the web. Operation of the motor is controlled in response to a change in position of the edge of the moving web with respect to the edge position sensor by a pneumatic control system which provides an immediate operation of the motor in response to the sensor and without a hunting tendency.

Abstract: An apparatus for punching holes in thin sheet stock includes an improved clamping arrangement which holds the sheet stock firmly during the punching operation in the regions surrounding the hole to be cut as well as in the slug region which is to be cut from the sheet.