Abstract: Dimpling of a workpiece by rebounding of a magnetic repulsion punch mechanism, when operated at high punching rates, is avoided by application of a damping pulse at a point at or subsequent to a mid-point of a return stroke of the punch from the workpiece and preferably within the last 10% of the return stroke. This damping pulse is preferably a fraction of the pulse width and of approximately the same amplitude as a driving pulse applying kinetic energy to the punch for causing punching of the workpiece. At high punching rates the kinetic energy of the return portion of a punching stroke is substantially determined by elastic rebounding of the punch from a guide bushing. The removal of kinetic energy during the return portion of the stroke allows the return of the punch to a position close to a rest position during a very short interval with small overshoot under control of mechanical damping.

Abstract: The present invention relates generally to a new apparatus and a method for non-destructive inspection and/or measurement. And, more particularly, the invention encompasses an apparatus that has a flexible foil or membrane secured thereto which conforms to the surface of the part that is being inspected and/or measured in a nondestructive manner using differential pressure.

Abstract: Dimpling of a workpiece by rebounding of a magnetic repulsion punch mechanism, when operated at high punching rates, is avoided by application of a damping pulse at a point at or subsequent to a mid-point of a return stroke of the punch from the workpiece and preferably within the last 10% of the return stroke. This damping pulse is preferably a fraction of the pulse width and of approximately the same amplitude as a driving pulse applying kinetic energy to the punch for causing punching of the workpiece. At high punching rates the kinetic energy of the return portion of a punching stroke is substantially determined by elastic rebounding of the punch from a guide bushing. The removal of kinetic energy during the return portion of the stroke allows the return of the punch to a position close to a rest position during a very short interval with small overshoot under control of mechanical damping.