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. 1922 Excerpt: ... on the other is turned a snug sliding fit for the reamed hole of the work. The sequence of motions therefore is, that one turn of the coarsepitch thread tommy screw lowers the clamping blocks, the work is inserted, and the screw given one turn to the right. This forces the wedge and raises the clamping blocks which ...
Read More
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. 1922 Excerpt: ... on the other is turned a snug sliding fit for the reamed hole of the work. The sequence of motions therefore is, that one turn of the coarsepitch thread tommy screw lowers the clamping blocks, the work is inserted, and the screw given one turn to the right. This forces the wedge and raises the clamping blocks which bring the work up square and tighten it on the locating pin. The work is thus supported solidly, and a milled face parallel with the center line of the hole is insured. The cutter for this job is a shell end mill 4 in. in diameter, with 19 teeth carried on an arbor secured by a draw-back bolt. A ROTARY MILLING FIXTURE The sketch, Fig. 222B, shows a rotary milling attachment which is designed for use in connection with a plain milling machine. It is mounted to revolve in a vertical plane so as to clear itself of chips readily and also to make use of a short-shank end mill, thus gaining the maximum rigidity which it is possible to obtain in the machine. The milling machine on which this fixture is used is equipped with a power-driven rotary table attached to a knee casting which slides on the column of the miller, and the fixture is located over a central stud and secured to the rotary table by means of two heavy cap screws, while two steel studs in the back of the fixture serve to impart to it its rotary motion, by engaging the rotary-table platen. In Fig. 222B, which shows a plan and side elevation of the fixture, A is a disk of cast iron machined all over and having mounted upon its front surface eight segment plates, B, of hardened tool steel, which are fastened by means of fillister screws and dowel pins from the rear of the plate and which have their front surfaces checked or roughened so as to give a good gripping effect when the work is cl...
Read Less