GB1193762A - Heat Treating Method and Apparatus - Google Patents

Abstract

1,193,762. Roller conveyers. ALCO STANDARD CORP. 2 July, 1968 [10 July, 1967], No. 31501/68. Heading B8A. [Also in Division F4] Apparatus for the heat treatment of workpieces comprises a furnace 20 heated by electric radiant tubes 24 in an air-tight shell 17, a loading chamber 40, by the side of this a quenching chamber, a rollerway hearth in the furnace in which the rollers 23 are adapted to be rotated alternately in opposite directions giving a reciprocating motion to a charge basket 10, and rollers 54 in the loading chamber for moving the charge basket over idler rollers 56 to and from the furnace. A reversible electric motor 77 drives the rollers 54 through a worm and pinion 80, 81 and chain and sprocket gearing 85, 86, 87 and 89, and also drives the rollers 23 through a magnetic clutch 91 and chain and sprocket gearing 93, 94, 95, 97 and 98. The limited alternate rotary motion of rollers 23 is produced by an hydraulic motor 100 with a piston 104 having rack teeth engaging a pinion 106 transmitting the motion through a magnetic clutch 109. The extent of the movement is controlled by limit switches LS1, LS2 disposed in a circuit incorporating a four-way valve controlling the motor 100 (Fig. 9). A vacuum door 57 and a furnace door 64 are operated by hydraulic motors 63 and 65 as disclosed in Specification 1,128,769. A pneumatic pusher 70 pushes the charge basket from loading chamber 40 on to rollers on an elevator in the quenching chamber. In operation the shell 17 is evacuated and after the basket 10 has been inserted through door 51 into chamber 40 the latter is purged with H 2 or N 2 .