Foundry Practice; A Text Book for Molders, Students and Apprentices

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ...is cut still further to connect the skim gate A with the set gate and a core is set in the skim gate, being marked "skim core" in the plan. The action of these various gates is as follows: Iron being poured fast enough to fill or "choke" the gate B, fills the gate C, which assists in restraining any ... Read More

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ...is cut still further to connect the skim gate A with the set gate and a core is set in the skim gate, being marked "skim core" in the plan. The action of these various gates is as follows: Iron being poured fast enough to fill or "choke" the gate B, fills the gate C, which assists in restraining any dirt in the iron. The iron entering gate A, shown in the plan, and flowing underneath the core, is skimmed by the core and the dirt is still further restrained. The round part of the set gate continues this action and the iron, flowing through a deep thin channel into the mold, has but little chance to carry dirt or scoria with it into the mold. As dirt or scoria in iron has a tendency to rise to the surface, the molder can, by contriving his gates to present pockets or skimming arrangements similar to the one described above, prevent a large amount of these impurities from passing into the mold with the iron. An arrangement sometimes used is similar to that just described, with the exception that the skim gates are omitted, the set gates being depended on to dam the iron and thus hold back the scoria. It is, however, necessary to keep the gate B choked, inasmuch as the scoria, being more fluid than the iron, will flow along the surface of it if it is given a chance to enter the cross gate, and thus get into the mold. As a general rule, a shallow, wide gate will permit more impurities to enter the mold than will a deep, narrow one. The arrangement of the gates, shown in plan and elevation in Fig. 129, 1 and 2, is shown in perspective at 3, and the course of the iron can be traced through it. Many styles of skim gates are on the market, some of them being patented. A peg gate is shown in Fig. 129, at 4 and 5. This consists... Read Less