| 摘要 |
1,207,176. Pressure die-casting. UNION CARBIDE CORP. 28 Sept., 1967 [3 Oct., 1966], No. 44163/67. Heading B3F. [Also in Divisions Cl and F2] In die-casting apparatus for casting aluminium a resilient sealing member 17 is placed between the end of a gooseneck passage 14 and a shot cylinder 20. The end of the gooseneck passage is formed with an internal protrusion 18 on which the sealing member is placed and the shot cylinder 20 has a flange 21 that engages the seal. A pump assembly housing 22 bears down on the flange 21 to facilitate the seal. The seal member is made from an expanded graphite formed by treating graphite particles with an oxidizing agent, such as a mixture of sulphuric and nitric acid, heating the treated mass to below the boiling point of the acid mixture, washing the treated graphite, and then further heating the washed graphite. The graphite may then be mixed with a binder and moulded to the required shape. Alternatively the first heating stage and the binder may be omitted. In an alternative embodiment (Fig. 3, not shown) the seal is formed between an inclined protrusion (36) and the flange 21 by compressing expanded graphite therebetween, |
