GB572930A - Improvements in or relating to the surface hardening of metal articles - Google Patents

Abstract

572,930. Surface hardening metal articles. SHORTER PROCESS CO., Ltd., and SHORTER, A. E. June 3, 1942, No. 7537. [Class 72] In the surface hardening of a localised portion of a metal article, high temperature heat is directed on the article which is simultaneously rotated about an axis normal or substantially normal to the surface, so that the whole of the latter is substantially simultaneously raised to a predetermined uniform temperature and is then cooled. The articles A are placed in a drum M and are fed in turn into one of the jigs J-J8, Fig. 2, carried by a drum D which is mounted on a shaft 10 and rotated in the direction of the arrow. Each jig is mounted in a spindle 12 provided with an annular boss or friction wheel 13 adapted, when at the heating station, to engage frictionally with a disc 14 mounted on a shaft 15 which is journalled in bearings supported by the framework F and driven by a continuously rotatable electric motor 16. The burner unit A comprises a burner 17 mounted in horizontal overhead slides 18, 19 and supplied with an oxy-fuel mixture through valves 20, a pilot jet 22 also being provided. The quenching unit Q is supplied by a pump 24 from a reservoir 23, water discharged by the unit being led back to the reservoir by a shoot 26. The articles in the housing M are fed by gravity to a plunger 28 operable by a solenoid 29 which along with driving mechanism 11, the motor 16, the motor 25 and the solenoid 29 are controlled by relays 31 connected to the push-button switches 31- 35 mounted on a panel 37. When the drum D is in the position shown in Fig. 2, the jig J is the heating station and the jigs J2, J3 are loaded each with an article. Switches 31, 32, 33 and 34 are now placed in the " on " position and the gas valve 20 turned on simultaneously with the closing of switch 35. Immediately the disc 14 is set in motion so that the article is rotated as the heating flame impinges on it. At the conclusion of the heating period, the mechanism 11 imparts an impulse to the shaft 10 to rotate the drum D through one-eighth of a revolution and this brings the jig J into the quenching position where water or other cold liquid is directed upon the article. During the progress of jig J to the quenching position, jig J2 is being moved to the heating position and disc 14 rotated and when this jig is in that position the solenoid 29 is energized momentarily by one of the relays 30 to feed an article into jig J4. When the jig J reaches the position occupied by jig J6, Fig. 2, the article A falls out of its jig and drops into the shoot 26. When, in treating certain articles, it is necessary to cool the article immediately after it has been heated, a heat treating device may comprise both heating and quenching means and then the drum is allowed to remain stationary for a period sufficient to enable both operations to be carried out, the duration of both being determined automatically by timing mechanism. The article may be tempered by reheating the quenched surface so as to impart greater toughness to it.