Gear cutting in theory and practice - Softcover

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. 1914 Excerpt: ...the carriage can be moved on the bed and brought back to the same position. Before beginning to cut, tighten the gibs, swing up the stop it, and adjust the screw xx until the end bears against the top screw vv. Setting the Cutter.--The cutter is set centrally on the cutter spindle by the indicator, as for spur gears mentioned on p. 116. But as a cutter cannot be thicker than the width of the space at the small end of the teeth, the cutter must be set out of centre for the large end, and the blank rotated to right and left to give the correct width and bevel. To indicate the amount of movement of the cutter out of centre a graduated dial is provided reading by a vernier to thousandths of an inch. It is shown at NN, Fig. 151, and the enlarged section above is the pinion and rack on the spindle sleeve by which the spindle is adjusted endwise. The two set screws retain the teeth and this spindle in position. They must be slackened before making adjustments, and after tightening they are secured with lock nuts. The Birch Automatic Machine.---The next gear-cutting machine is of a type that has long been employed in English shops, comprising two beds set at right angles, one carrying the workspindle slide, the other the cutter-spindle slide. This is a simple construction, and one that was probably evolved from the lathe, when the headstock was first utilized for dividing, with Fig. 150. the cutter held in the slide rest. In many machines the dividing is done by hand, but the example taken is fully automatic, and is made in several sizes, up to 8ft. diameter capacity. The drawings show a 2ft. machine in detail. Some designs are made for cutting spur gears only, but the present example is capable of cutting, in addition, bevels and worm gears. It is possible to prod...