Portable device for cutting the inside wall of a tube by a continous arc

Abstract

A spark disintegrator tube cutter comprises a housing having a shaft with armature rotatably mounted in the housing. A conductive base which is electrically connected to a post accessible from outside the housing, carries a carbon brush against which the armature slides. The post is used to supply electricity to the shaft. A flexible shaft extension is connected to the shaft and carries a cutting electrode which extends radially outwardly from an end of the shaft. A spacer which is engaged around at least part of the shaft extension on an opposite side from the cutting electrode, and urges the cutting electrode against the inner circumferential surface of the tube to be cut. A pneumatic motor mounted to the housing and connected to the shaft, rotates the shaft. With dc current passing through the cutting electrode, an arc is formed as the electrode slides in continuous contact around the inner circumference of the tube, for cutting the tube.