| 摘要 |
1352748 Making welding torch nozzles SMALL TUBE PRODUCTS Inc 19 April 1971 [18 Feb 1970] 23948/71 Heading B4A [Also in Division F4] In a method of making a welding torch nozzle, two seamless drawn tubes 11 and 19 are arranged concentrically one inside the other, the outer tube 11 is drawn to reduce its outside diameter and to bring it into engagement with the inner tube 19 to form a composite tubular member. One end of the composite tube is then tapered to form a nozzle tip and the other end is formed with an external thread thus completing the formation of a nozzle 37. In an alternative embodiment the bore of the external tube 45 is provided with a plurality of longitudinally extending grooves 43 which provide in the finished nozzle 41 passages for the passage of gases which in operation shield the gases emitted from the main nozzle bore 61. |
