Plasma cutting and welding torches with improved nozzle electrode cooling

摘要

A plasma torch (40) comprises a handle (41) having an upper end (41B) which houses the components forming a torch body (43). Body (33) incorporates a rod electrode (10) having an end which cooperates with an annular tip electrode (13) to form a spark gap. An ionizable fuel gas is fed to the spark gap via tube (44) within the handle (41), the gas from tube (44) flowing axially along rod electrode (10) and being diverted radially through apertures (16) so as to impinge upon and act as a coolant for a thin-walled portion (14) of the annular tip electrode (13). With this arrangement the heat generated by the electrical arc in the inter-electrode gap is substantially confined to the annular tip portion (13A) of electrode (13) which is both consumable and replaceable in that portion (13A) is secured by screw threads to the adjoining portion (13B) of electrode (13) and which is integral with the thin-walled portion (14).