GB191414A - Improvements in methods of and apparatus for forming gear teeth and the like - Google Patents

Abstract

191,414. Imray, O. Y., (Schmick Gear & Screw Co.). July 6, 1921. Gear-cutting; attachments for planing.- In a machine for cutting gear teeth, cam grooves &c. the cutter and work are moved relatively in a rectilinear path which is substantially at right angles to the blank axis, the blank being angularly indexed and the tool moved axially of the blank between successive cuts so that a worm &c. is produced by a series of overlapping cuts. In some cases the blank may be rotated in either direction during the cut so that the bottom of each cut may be of convex or concave form. In Figs. 2 and 3 the blank 17 is mounted on an arbor journaled in a frame 12 supported on a table 11 reciprocated beneath the adjustable cross-rail 14 carrying the cutter 15. The work arbor carries a gear 20 engaging a loose gear 21 on a shaft 22 carrying also a splined gear 23. The latter may engage a rack 24 on the machine frame to rotate the blank during the cutting stroke or may be held stationary by means of a stud 25. The loose gear 21 is provided with a series of holes in which a pin 27 on an arm 28 may be engaged to connect the gear to its shaft. The cutter 15 is mounted on a slide 16 adjustable by a handwheel 30 micrometer 31 and scale 32 the depth of cut being determined by the adjustment of a screw 34. In operation the work is rotated through a small angle prior to each cut by setting the pin 27 in the next adjacent hole and the cutter 15 spaced axially of the work by the micrometer 31. The groove is thus produced by a series of cuts 55 each displaced circumferentially and axially of the blank with reference to adjoining cuts, as shown in Figs. 9 and 10. In a modification Fig. 6, cutters 35 may be radially arranged on a pivoted cutter block 36 and rotated intermittently between successive cuts bv means of an indexing device 37 the blank 39 being indexed as above described. In a further modification Fig. 8, the work arbor provided with an index plate 44 may be mounted in a frame 43 supported on the table 47 of a planer and the side cutting edges of each tooth of the cutter 48 are preferably set one in advance of the other, one such arrangement being shown in Fig. 11. Multiple threads may be cut in the blank by increasing the axial displacement between successive cuts. The frames 12 and 43 may be mounted on a milling machine or shaper table the method of operation being as above described.