Book Description

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. 1903 edition. Excerpt: ...The Fellows Gear Shaper goes back to first principles and generates its tooth form from flat and circular surfaces which can be made absolutely true and can be proven to be so. The work is done automatically, by a circular cutter of the correct pitch. An example of the work produced is shown in fig. 160. This is effected as follows: The blank to be cut is securely fixed on the work arbor and the machine being started, the cutter reciprocating vertically on its center line is fed towards the blank, and cuts its way to the proper depth; at this point both cutter and blank begin to revolve, the cutter maintaining its reciprocating motion; this revolution of the cutter and blank is obtained by external mechanism, which insures that the movement SHAPING MACHINES. shall be as though the cutter and blank were two complete gears in correct mesh; fig. 161 shows a section through the centers of blank and cutter which will explain the process of cutting an external-toothed gear wheel; internal gears can be cut with equal ease and regularity. Fig. 161 shows the action of the gear cutter, also each cut and the wedge form of the gear shaper chips. The combined result of rotary and reciprocatory motions is that the cutter teeth generate conjugate teeth in the blanks which mesh correctly with the cutter teeth and with each other. Fig. 162 illustrates a device for setting planing or shaper tools; it consists of a body containing a spirit level, the bubble of which appears through an elongated opening DEVICE FOR SETTING TOOLS. formed in the top plate, attached to the body and provided at its side with linear graduations having their zero points coinciding with the zero point of the bubble. The body is provided with a downwardly extending web terminating in...