A NOZZLE HOLDER FOR A LIQUID COOLED ELECTRIC WELDING GUN

摘要

A liquid cooled electric welding gun having a handle (53), a tubular conductor (55) extending forward from the handle (53), and a liquid coolant supply passage (63) and a liquid coolant return passage (65) in the conductor. A tubular nozzle holder (71) is secured to the conductor and removably holds a metal nozzle (73) at a forward end of the conductor. The nozzle holder has an outer metal layer (81) engageable by the nozzle and an inner layer (87) of electrically insulating material disposed between the metal layer and the conductor for electrically insulating the conductor from the nozzle. The nozzle holder defines a liquid coolant chamber (103) in direct fluid communication with the liquid coolant return and supply passages and with the outer metal layer of the nozzle holder to enable direct contact of the liquid coolant with the outer metal layer for efficient transfer of heat away from the metal nozzle. Seals (115) prevent leakage of liquid coolant from liquid coolant chamber when the nozzle is removed from the nozzle holder.