| 摘要 |
1497805 Nozzles BOC INTERNATIONAL Ltd 28 Aug 1975 [28 Aug 1974] 37612/74 Heading F4T A nozzle for a cutting blow lamp comprises an inner member 2, having a passage for cutting oxygen 4 along its axis, and a hollow member 6 encircling member 2, the outer surface of the latter being chemically etched to form mixing passages 22 at the joint face between the members. A tip 14 has an axial passage 18 for the oxygen and a circular series of passages 20 which may be of circular, triangular or rectangular cross-section, for the preheat gas, and is secured to body 6 by a nut 16. Passages 22 are connected to the oxygen and fuel gas sources through radial passages 24 and 26, respectively. The joint face between the members may be parallel, as shown, or it may be tapered. To produce passages 22 on member 2, the outside of the latter is covered with a layer of photosensitive gel, and a mask having the shape 28, 30, 32, is placed on the member which is then exposed to light so that the uncovered part of the gel is hardened. The mask, and the unhardened gel are removed and the member is immersed in a chemical etching bath so that the metal is removed and the passages are formed. |
