GB834297A - Improvements in or relating to the induction hardening of metal articles - Google Patents

Abstract

834,297. Heat treating. DAVEY, PAXMAN & CO. Ltd. March 6, 1958 [March 12, 1957], No. 8139/57. Class 72 A method of induction hardening cylindrical members comprises the progressive heating and immediate quenching of successive circumferentially extending bands of the work surface by the axial movement of combined induction and quenching means from one end to the other, followed by the heating and immediate quenching of the zone of the work surface lying immediately beneath the induction means at the completion of its travel. As shown, a combined induction coil and quenching ring is split into two sections with end lugs 3 hinged at 4 to a travelling carriage (not shown), and lugs 5, which can be joined by a swinging bolt 6, having silver electrical contacts 20 which engage and thus complete an electrical H.F. circuit from one lug 3 to the other. In operation, during the traverse, liquid is passed from connections 16 into chamber 14 and issues from perforations 18 in wall 9 on to the part of the heated surface of shaft 2 over which the coil has just passed. When the right hand end (Fig. 2) of neck 21 is reached, additional liquid is supplied through connections 17. chamber 15 and perforations 19 against fillet 22 from which it is deflected to the zone immediately beneath the induction coil. In an alternative embodiment (Fig. 5) the functions of chamber 15 and perforations 19 are taken over by chamber 23 and perforations 24 while chamber 25 forms a cooling liquid circuit from lug 3 through one half section 1 and passing to the other by means of a flexible hose returning to the other lug 3 and to waste.