GB580976A - Improvements in or relating to the heat treatment of metal plates - Google Patents

Abstract

580,976. Heat-treating metal plates. BUDD INDUCTION HEATING, Inc. July 9, 1942, No. 9581. Convention date, Nov. 8, 1941. [Class 72] Equal portions of each face of a metal plate are heated, e.g., by electro-magnetic induction, substantially simultaneously to a predetermined depth without substantially heating the rest of the metal and the heated portions are quenched equally rapidly, so that each face of the plate is hardened to substantially the same depth without bending of the plate. The plate treated may comprise two plates clamped together so that only one side of each plate is treated and the plate may be treated progressively along its length. A frame 10, Fig. 2, carrying rollers 12 is pivoted at 11 to the main frame, so that it can be opened by a handle 13 to allow the placing of a plate 25 against rollers 15 carried by the main frame and then moved back so that the plate 25 is engaged by both the rollers 12, 15. Other rollers not shown engage the sides of the plate and a further pivoted plate arranged at right angles to the plate 10 may be provided. Arranged above the rollers 12, 15 are straightening rollers 22, 23, 24 and the plate 25 is fed up between these rollers by a motor or by a fluid pressure motor comprising a cylinder 26 and a piston 27 and piston rod 28 which extends up to a connection 29 bolted to the plate 25. Between the rolls 22, 23 are arranged inductors 30, 31, and quenching heads 32, 33, supplied with liquid from headers 34, 35, surplus liquid being collected in a trough 36. During the passage of the plate through the rollers 22, 23 other rollers engage the edges of the plate. One of the inductors is shown in Fig. 7, the hollow inducting elements 46 being in a series of laminations 44 beneath a wedge 45 holding them in place and surrounded by insulation 47. The laminations are held in place by a cap 49 clamped to a block 48 by bolts 50, and the inductor is spaced from the wall of the main frame by a block 51 clamped to the block 48 by bolts 52. The quenching head 33 is in two parts secured in position by bolts 81, the lower part being secured to the block 48 by bolts 80, and is provided with an elongated space 77 for the liquid from a pipe 35a and in which is located a baffle 78 which spreads the liquid laterally of the pipe and equalises the liquid pressure, to produce a uniform quantity and velocity of liquid to be ejected by the jet 79. In operation, the plate 25 is placed between the rollers 12, 15, the frame 10 closed and fluid pressure admitted to the cylinder 26. The plate is raised and passed through the straightening rolls and after being straightened is pulled down slowly and propressively heated to the hardening temperature by the inductors and quenched. In another form of apparatus, the rolls and the heating and quenching heads are arranged horizontally, and the plates are pushed through the rolls &c. but in this form the plate is heated and quenched before being straightened.