GB113966A - Improvements in Gear Wheels and Method of Manufacturing same. - Google Patents

Abstract

113,966. Wingqvist, E. H. March 8, 1917, [Convention date] Gear - cutting Milling-cutters. - Bevel and s p u r gears are formed with curved teeth such that the lines of intersection between the tooth faces and the pitch cylinder or cone form, when developed in a plane, congruous parts of parallel, periodical curves. K, L, M, N, Fig. 1, represents the pitch cylinder of a spur gear developed and Z a prolate cycloid, being the path of a point E connected to a circle of radius r rolling on a line J-J and coinciding with one face e-e of a tooth. All the tooth faces are of the same curvature and, for bevel gears, prolate epicycloids or hypocycloids are employed, the tooth shape being involute for spur and octoid for bevel gears V, Fig. 29. In cutting spur gears, the cutters A, B, C, &c., Fig. 1, are carried by a disk W, Fig. 2, rotating on a fixed axis, and, in order that they shall act successively on the front and rear faces a-a, b-b, c-c &c., the blank H rotates in the direction of the arrow 0 at a corresponding speed. In addition, the blank is given a rolling movement in the same direction so as to deepen the tooth spaces gradually. To produce involute teeth, the opposite faces of alternate cutters A, B, - - F, G i.e. the cutting faces, are shaped, as shown in Fig. 24, to correspond to halves of the teeth of the imaginary rack T, Fig. 2, with which the blank H may be regarded as being in gear.