Disintegrating electrodes

An electrode for forming a radially extending hole in a pipe, said electrode comprising a rigid and electrically conductive tubular sheath adapted to be connected to a voltage source, said sheath having inner and outer walls of circular cross-section and having a working end adapted to be positioned adjacent said pipe, the opposite end of said sheath being adapted to communicate with a source of liquid coolant, a cluster of rigid and electrically conductive tubes of circular cross-section fixed within the working end portion of said sheath and adapted to communicate with said source of liquid coolant, said tubes being arranged in a circle around the inner wall of said sheath, the coolant being delivered to the working end of said sheath and to said workpiece through said tubes, and flow spaces within said sheath between said tubes for also delivering coolant to the working end of said sheath and to said workpiece.

A disintegrating electrode for forming a hole in a metal workpiece, said electrode comprising a rigid and electrically conductive tubular sheath adapted to be connected to a voltage source and having an electrically uninsulated outer wall, said sheath having a working end adapted to be positioned adjacent said workpiece and having an opposite end adapted to communicate with a source of liquid coolant, a cluster of rigid and electrically conductive members fixed within the working end portion of said sheath, and flow spaces within said sheath between said members for delivering coolant to the working end of said sheath and to said workpiece.

A disintegrating electrode for forming a radially extending hole in a pipe, said electrode comprising a rigid and electrically conductive tubular sheath adapted to be connected to a voltage source, said sheath having inner and outer walls of circular cross-section and having a working end adapted to be positioned adjacent said pipe, the outer wall of said sheath being electrically uninsulated at least adjacent the working end of the sheath, the opposite end of said sheath being adapted to communicate with a source of liquid coolant, a cluster of rigid and electrically conductive tubes of circular cross-section fixed within the working end portion of said sheath and adapted to communicate with said source of liquid coolant, solid rods of electrically conductive material fixed within the working end portion of said sheath, said tubes occupying a greater cross-sectional area of said sheath than is occupied by said rods, coolant being delivered to the working end portion of said sheath and to said workpiece through said tubes, and flow spaces within said sheath between said tubes and said rods for also delivering coolant to the working end of said sheath and to said workpiece.