Abstract: The work clamps of a punch press are mounted in laterally spaced relation on a carriage which may be shifted to cause the clamps to re-position a workpiece relative to the punch. To enable automatic adjustment of the lateral position of the clamps on the carriage, each clamp is adapted to be selectively and automatically locked to or released from the carriage. When released from the carriage, each clamp is adapted to be automatically held in a stationary position so that the carriage may be shifted relative to the clamp to permit re-positioning of the clamp along the carriage.

Abstract: Punch presses are positioned for punching holes at selected vertical locations in the flanges of I-beams, angle irons and channels by apparatus which utilizes a movable probe to determine the initial position of the presses and which further utilizes a reversible counter and a comparator to stop the presses after they have moved a selected distance from their initial position.