GB775716A - Improved method of cutting helicoidal surfaces on face toothed members - Google Patents

Abstract

775,716. Grinding. GLEASON WORKS. April 19, 1955 [April 19, 1954], No. 11296/55. Class 60 [Also in Groups XXII and XXIV] A method of simultaneously cutting helicoidal surfaces 35a, 35b of opposite hand on opposite sides of spaced teeth 22 of a face toothed member 20 consists in effecting a relative feed in a plane 37 common to the work axis 24 and the axis 27 of an annular cutter 26 presenting a tip edge cutting circle 41 to the work to cause the cutting circle to traverse both surfaces. simultaneously, the feed including an angular motion which maintains the cutting circle substantially tangent to the tangent. planes of the helicoidal surfaces at mid-points 43, 44 along the length of the teeth. The inside edges 25 of the cutter 26 cut opposite sides of spaced teeth and the work is indexed until all the teeth have been cut. The edges are inclined to the cutter axis so that the cutter teeth can be relieved axially. When the teetli are sharpened, therefore, the cutting edges recede axially (25<SP>1</SP>, Fig. 4) and a simple axial adjustment only of the cutter is necessary to restore the correct cutting relationship. The helicoidal tip surfaces, 35a, 35b of the teeth are cut by the rounded edges 38 and the edge 39 of the cutter 26. The teeth of the mating clutch member 21, Fig. 7, are cut by the outside edges 29 of a cutter 31. The teeth of the member 20 in axial cross-section thus have chamfered surfaces of convex curvatures and the teeth of the member 21 concaxe curvature; they will thus have substantially full contact at their centre portions with ease-off at each end. If the helicoids of the surface are not of constant lead, the profiles will be curved instead of straight as in Fig. 2. In a grinding machine, the member 20 is mounted for axial adjustment with an indexing mechanism 64 on a slide 62 adjustable vertically on a column 58. The column is adjustable about an axis 61 on a slide 56 adjustable on a base 55 in directions 57. The grinding wheel 28 is mounted in a housing 66 adjustable in directions 60 on a base 70 pivoted at 69. The base is carried on a slide 67 which is moved in directions 71 by a cam 72 acting through a lever 73. A coaxial cam 77 acts through a lever 79 and bevel gearing 82, 83 to swing the wheel about the pivot 69 to follow a path 85, Fig. 9, to cut the chamfers 35 and the sides of the teeth. Reference has been directed by the Comptroller to Specifications 572,612, 594,492 and 624,769