Percussion instrument for diagnostic and testing purposes - includes rod which is magnetically retracted against spring pressure and released when current is manually or automatically disconnected

摘要

Well defined, constant mechanical shock pulses are generated singly or periodically, independent from the distance to the tested object. A movable metal rod is magnetically pulled against a helical spring pressure. When magnetising current is switched off, rod is accelerated by the spring and after release from the spring is horizontally guided in nearly free from friction bearings, hits the tested object and bounces off it more or less elastically. The magnetising coil current is automatically reconnected, the bar attracted by it and held at a certain stop until the current is manually or automatically disconnected, controlled by a suitable electronic circuit.