American Machinist Volume 31 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1908 Excerpt: ...inches over the cross slide. It is a most complete tool, comprising a friction-geared hcadstock, a hexagon turret 18% inches across, a square turret on the cross slide, and a chasing saddle for use with hobs. Seven horsepower is required for driving. The cone pulley has two broad steps for a 62-inch belt, and nine speed changes are obtained for each step by movements of the levers in front of the head, which is of advantage when turning and boring large and small sizes on one piece. The eighteen spindle speeds range from 8.2 to 200 revolutions per minute. The axis of the turret is inclined, to permit tools which project out to a long distance to clear the handles of the pilot wheel in front, by which the turret saddle is moved by hand. The turret is pierced by six 3J/-inch holes to allow bars to pass through. It receives 18 automatic feeds, coarse-and fine, tripped by six independent adjustable stops, any one of which is only operative when its particular tool is in action. The cross slide which carries the square turret has longitudinal and cross feeds, both reversible, with 9 changes. The slide is mounted on the chasing saddle which is operated by a leader or hob, independent of the automatic feeds. Four pitches can be cut by each leader, by changing the speed of the latter. There is an arrangement whereby the act of putting in the nut to the hob also runs the tool up to position, and vice versa, without interfering with the usual hand-wheel feed, employed for setting the depth of cut. Turning and chasing can be done on the same piece, the change being made instantly, but without any risk of both being in gear simultaneously. boring and turning small and large diameters. A double countershaft is used for driving these. Sixteen spindle speeds in all are a...