Patent GB-818879-A (GB)
Title: Improvements relating to rotary face mill cutters for cutting gears or like toothed parts, and to machines employing such cutters
IPC: B23F1/08
Filed: 1957-09-04
Abstract: 818,879. Gear-cutting. GLEASON WORKS. Sept. 4, 1957 [Sept. 25, 1956], No. 27985/57. Class 83 (3). Apparatus for generating or form-cutting gears and like toothed-parts comprises a face mill-cutter having a number of equally-spaced roughing blades 128, 129, Figs. 5 and 6, followed by at least one finishing-blade 138, the side cutting-edge of the finishing blade being inset with respect to the adjacent roughing- blade so as not to cut except upon a terminalinfeed occurring after the cutting action of the last roughing-blade during the last revolution of a cutting cycle. The gear G, Fig. 2, on a spindle 32, is carried on a slide 31 vertically movable on a slide 28 movable on a platform 24, adjustable angularly about an axis 25 on a slide 22. The cutter C rotates in a housing 37 adjustable to move the cutter laterally or angularly relatively to a cradle 35, having its axis 36 intersecting the axis 25. A two-speed motor 41 (1800 or 600 r.p.m.), rotates the cutter C and a barrel-cam 46, Fig. 3. When gears are to be generated, a groove 55 in the cam 46 rocks the cradle 35 in time with the work-spindle 32. For form-cutting gears, angleof-roll change-gearing 59 is removed and a shaft 67 and the cradle 35 are clamped against rotation. The work is withdrawn after the generation of each tooth-space, by engaging a roller 96 with a groove 94 in the cam 46, the groove having a straight portion to hold the slide 22 at a fixed depth for cutting. During form-cutting, the roller 96 is disengaged, and a roller 95 is engaged with a groove 93 to give a gradual feed of the work to cutting-depth. During withdrawal movements in each case, the work is indexed by a Geneva-type mechanism 82, 83, engaged by a cam 84. The connection between the cam-grooves 93, 94 and the slide 22 is by way of a lever 97 having a sliding- block engaging a cylinder 103, in which a piston 104 is hydraulically-locked. The piston 104 is connected to the work-carrying slide 22 by a rod 105, there being means 106 to adjust the depth of cut. The working position of the piston 104 is determined by abutment against a two-position hydraulically-operated stop. When the piston 104 is moved to its opposite limit-ofmovement against the end of the cylinder 103, it withdraws the slide 22 to enable the work to be removed. The cutter-head 123, Fig. 5, has equally-spaced, alternate outside and inside roughing cutters 128a, 129a, &c., Fig. 6, clamped in equally spaced recesses 126, followed by outside and inside finishing cutters 138, 139 spaced so that the work can be fed in after, say, six-and-a-half revolutions of the cutter, when the blade 129h is clear of a tooth, so that the finishing cutters cut consecutively to finish a tooth-space. The in-feed is achieved by actuating a valve 116, Fig. 3, by a camgroove 119 on the cam 46 to move the hydraulically-operated stop, against which the piston 104 abuts in its working position. Just prior to the in-feed, a cam 142 on the cam 84 adjusts the motor 41 to its lower speed which continues until finish-cutting is complete. In a modified cutter, separate bottom-cutting roughing-blades are interposed. between each pair of sidecutting blades.