GB551975A - Improved method of and apparatus for cutting gears - Google Patents

Abstract

551,975. Gear-cutting. GLEASON WORKS. April 28, 1942, No. 5707. Convention date, Aug. 1, 1941. [Class 83 (iii)] In a method of and means for cutting gears particularly for fine pitch straight bevel-gears, a reciprocatory tool has two cutting edges one behind the other, one edge cutting on one side and the other on the other side of a tooth space. The tools T, T<SP>1</SP> may be used in a bevelgear generator of the kind described in Specification 212,862, [Class 83 (iii)], being mounted in . tool boxes carried by slides 12, 13 moving on angularly adjustable arms 14, 15 reciprocated alternately by crank mechanism including an oscillating plate 16. The usual clapper mechanism is provided. Each tool, Figs. 3 and 5, comprises a plate 25 secured to the tool box by bolts. The leading part of the tool is a roughing portion and the following part a finishing portion. In order that the tool may be used on either slide it is preferably formed with two roughing portions 30, 32, adapted to cut in opposite directions and a double-ended finishing portion 31. The face 38 of the part 30 is formed with side and bottom rake so that it cuts on the edge 39, Fig. 3, while the face 49 of the finishing portion is raked so as to form a sharp cutting edge on the opposite side 51. The corresponding edges 41, 52 which are used when the tool is mounted on the opposite slide are similarly formed. The bottom edge 46 of the finishing part takes no part in the cutting and is located at a distance d, Fig. 3, below the bottom edge 36, of the roughing part. When the tool is in use it is .tilted as shown in Fig. 5 to obtain a bottom clearance angle c. In this position the edge 46 does not touch the work. The two tools are' reciprocated towards the cone apex and are either rolled relatively to the work or fed to depth by a non-generating action. The respective positions of the tools in cutting are shown in Fig. 4. Thus in one space the tool, T<SP>1</SP> roughs out the flank 69 with the roughing edge 39 and finishes the opposite flank with the finishing edge 52. In the next space one flank is finished by the edge 51 of tool T and the other roughed by the edge 39. Indexing is in the direction of the arrow 66 so that during the next operation the tool T<SP>1</SP> operates in the space 71 while the edge 69 is finished by the edge 51 of tool T. In a modification the tool may be non-reversible having two cutting parts only. In another modification the different sections of the tool may all be roughing parts, and the cutting edges may be of any desired profile instead of being straight.