PLASMA ARC COLLIMATOR DESIGN AND CONSTRUCTION

摘要

An improved collimator(102) for a plasma arc torch (12) consistsof an annular holder member (104) and aninsert member (118). The insert member(118) includes a tubular stem portion (120)ending in an integrally formed, radiallyextending face plate (132). When the stemportion (130) is Fitted into the central bore(108) of the holder member (104) with apredetermined clearance fit therebetween, acooling water passage (124) is created. Theimproved collimator is characterized by theabsence of any welds between the holdermember (104) and the insert member (118)that would be exposed to conductive gasesgiven off during use of the plasma are torchand a lesser resistance to cooling water flowthan prior art collimator designs.