| 摘要 |
640,463. Making pipe fittings. NORTHERN INDIANA BRASS CO. June 27, 1947, No. 17015. Convention date, Sept. 28, 1946. [Classes 83 (ii) and 83 (iv)] Stamping.-In a method of making pipe fittings such as T's or Y's of substantially uniform thickness a capsule 4 of approximately the same thickness as the fitting is filled with a low melting-point metal 12 and pressed into a die with a smoothly-curved cavity by a plunger 13 with a shoulder 14 which feeds the capsule walls into the cavity, the ends of the fitting are sawn off and the filling melted out. The capsule is preferably of copper or a high copper alloy such as 85 per cent copper and 15 per cent zinc or may be a ferrous metal. The filler may be any low melting-point metal such as lead, type-metal or solder which does not react chemically with the capsule metal and may be inserted into the capsule in the molten state or in the form of a pre-cast slug. The capsule 4 formed by a drawing operation from a flat disc and containing the filler 12 is inserted into the feed passage 7 of a split die 5 into which the plunger 13 with a short supporting section 15 is introduced so as to compress the filler metal slightly before the shoulder 14 engages the capsule wall. On further lowering the plunger 13 the filler metal is bulged and carries the capsule wall, forced inwards by the shoulder 14, to fill the cavity 10 and the run passages 16 which have vents 9 to permit the escape of air. The ends of the run portions 16 may be sawn off before the filler metal is finally melted out. Fittings of similar shape may be made having the central cavity 17 of ellipsoidal or similar form with a smooth curved surface of larger cross-sectional area than the passages 7, 16 and smooth tangential reversed curved surfaces 11 at the entrance to the passages. |
