Publisher's Synopsis
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. 1917 edition. Excerpt: ...for the most part the lathe is used for work exactly concentric with the axis, it can be used for turning work not concentric with the axis. Work of this sort is termed "eccentric," and an example of such work is seen in the eccentrics which Amount of Taper in a Given Length, When the Taper per Foot is Known--Table 9 operate the valves of steam engines. If the work has a hole through it, as in the above example, the hole is first finished to required dimensions. A mandrel is then used for carrying the work on the centers. While the mandrel has been built on one set of centers exactly true with its axis, for eccentric turning it has a second set of centers which are offset the amount required for the eccentricity specified. In the case of eccentrics made solid with the shaft, the two sets of centers, one for turning the shaft and the other for finishing the eccentrics, are made side by side in the ends of the shaft, as shown in Fig. 28. When the specified eccentricity is too extreme to allow both pairs of centers coming within the limits of the diameter of the shaft, special ends may be cast or forged on the ends of the work, and can afterward be machined off. In crank-shaft turning, special attachments are provided for the ends of the shaft. Special eccentric turning chucks may be made to hold the work. CHUCKING. Chucking includes, not only the mounting of the work in the chuck, but performing the necessary operations on it while so held. The name "chuck" is given to a line of tools having a variety of form, all of which are designed to hold work or tools upon the nose of a spindle. In general the heavier sorts are mounted upon a face-plate which screws upon the end of the spindle, while smaller sizes are fitted with a...
