GB849230A - Improvements relating to induction heaters for billets - Google Patents

Abstract

849,230. Induction heaters for billets. OHIO CRANKSHAFT CO. Aug. 16, 1957 [Aug. 16, 1956], No. 26006/57. Class 39(3). [Also in Group XII] In induction heating apparatus for heating billets, a billet being heated in an induction coil is held-in position by a previously heated billet located in a soaking receiver. As shown in Fig. 1, two billets A, B are being heated in coils 10, 11 energised by three-phase supplies at mains frequency, the connections being such that the billets are urged along skid rails 17 in the direction of the arrows 15, 16 by the magnetic fields produced within the coils, and the billets contact the ends of a previously heated billet C in a soaking chamber 12. A billet D and a billet E are ready to be inserted into the coils by air cylinders 27, 28, billet C is ready for discharge from the chamber 12, and the coils have been de-energised. Air cylinders 24, 25 are energised to cause a door 22 to be raised and a piston 23 to move the billet C from the chamber along rails 18. The door and piston are then returned to their normal positions and the coil 10 energised, the billet A moving into the chamber and against the billet B in coil 11. At the same time, billet D is pushed into the coil 10 by energisation of the cylinder 27 and abuts against billet A. Coil 11 is then re-energised and billets B, D are heated until they reach full and intermediate temperatures respectively. At this time, billet A had gained a uniform heat pattern in the chamber and is removed via the door 22. Billet B is then inserted into the chamber and a new billet E inserted into the coil 11. Coil 10 is then re-energised. The cycle may be continued on succeeding billets. The door 22 may be opened manually and the air cylinders may be replaced by motor driven means or solenoid actuated devices. The chamber may be provided with auxiliary resistance heating elements 26 but gas burners or induction heating coils may be used. In a modification, Fig. 5 (not shown), only one heating coil is provided, and the end of the soaking chamber remote from the coil is provided with a stop with which the billets engage. In both embiodments, each coil may contain two or more billets at a time provided the axial lengths of the billets are appropriate to those of the coils and the chamber.