GB446821A - Method and apparatus for hardening the surfaces of metal articles - Google Patents

Abstract

446,821. Surface - hardening metal articles. I. G. FARBENINDUSTRIE AKT.- GES., Frankfort-on-Main, Germany. Nov. 2, 1934, No. 31498. Convention date, Nov. 2, 1933. [Class 72] In the surface-hardening of metal articles of varying cross-section, particularly the flanks of toothed wheels, by means of a burner, the distance of the burner from the surface is automatically increased as the flame of the burner reaches parts of the article of reduced cross-section and decreased for parts of increasing cross-section or the burner is moved at a constant distance from the surface and its velocity increased for the parts of reduced cross-section and decreased for parts of increasing cross-section. In the first form, Fig. 2, the burner 3 is mounted on a forked guide 2, the holder 1 being given a uniform straight line motion. A roller 7 on the burner 2 is kept in contact with the cam surface 5 of a plate 4 so that when the roller 7 moves along the surface 5 the distance of the burner from the article is altered. In the second form, Fig. 4, the burner holder 13 carried by the bed B is given a straight line motion at a constant distance from the article and the velocity of the burner is altered by the engagement of roller 12 with a cam plate 9 fixed to the holder 13. The roller 12 is mounted on a rod 11 connected to a friction disc gear 10 by which the velocity of the holder is adjusted. The motion of the holders 1, Fig. 2, and 13, Fig. 4, is effected electrically and controlled by suitable switching means operated by a time release device and relay gear, springs X, Y being provided which when the holder contacts with them close a circuit to cause the time release device to come into operation. To avoid overheating at the end of the flank of the tooth, that part is covered by a suitable heat resisting substance such as kaolin.