GB731951A - Improvements in apparatus for heat treating metal objects - Google Patents

Abstract

731,951. Heat treating metals. WELLMAN SMITH OWEN ENGINEERING CORPORATION, Ltd Dec. 22, 1953 [Sept. 25, 1952], No. 24075/52. Class 72. An apparatus for heat treating metal objects comprises gas-fired furnaces 1, 10 arranged in line end-to-end but spaced apart longitudinally, a quenching tank 22 between said furnaces and an air-cooling tank 25 immediately beyond the discharge end of furnace 10, both tanks being beneath the level of the furnace floors. At the beginning of a cycle of operations, a framework 48, displaceable by hoising gear 50, is in its lower position so that channel members 49, similar in cross-section to members 30 which run along the tops of both furnaces, are aligned with said members 30. The metal objects, e.g. shell-cases, are loaded on to carrier members such as 29, each consisting of a vertical body portion 35 and rollers 36 which engage the inner surfaces of the channel members; the mid-portions of the carrier members extend through slots 6 in the roofs of the furnaces, the furnaces also being provided with vertical slots opening into end apertures 9 to permit the passage therethrough of the objects being treated. A hydraulic ram 52 moves out and displaces the carrier members located on the channel members 49 on to the members 30, the loaded carrier members being moved along the members 30 by the ram pushing in further loaded carrier members. Each time the ram 52 is retracted the doors 56 of the furnace 1 are closed and the hoisting gears 42, 47 are operated to lower their respective frameworks 40, 44 which are similar to framework 48 and provided with channel members such as 45. Loaded carrier members are thus first displaced on to the framework 40, this movement actuating the quenching nozzles 23. After a predetermined time, the articles are further moved into the furnace 10 and thence on to the channel members 45 of framework 44, said framework having, in the course of its journey downward, operated a switch for actuating the means for lifting the cover 61 of the air-cooling tank 25 and for actuating the air-cooling fan supplying an air blast through the duct 26. After a predetermined time, the air blast is stopped, the shellcases unloaded and the frameworks 40 and 44 raised so that their channel members are aligned with fixed guideways 46. Ram 55 then moves out to displace the unloaded carrier members from channel members 45 into the guideways 46. The returning of unloaded carrier members is thus made by a series of step-wise advances in synchronism with the advance of the loaded carrier members through the furnaces. This return may however be effected in a single continuous movement.