GB626403A - Improvements relating to apparatus for charging and discharging a furnace - Google Patents

Abstract

626,403. Charging metal-heating furnaces. AJAX ELECTRIC CO., Inc. May 9, 1947, No. 12578. Convention date, July 26, 1946. [Class 51 (ii)] [Also in Group XXX] Apparatus for charging and discharging a furnace having an upper charging aperture, e.g. a salt-bath furnace, comprises at least one pair of inclined guides extending downwardly into the furnace and adapted to engage and support the sides of a billet, a yoke adapted to embrace the billet and engage the lower end thereof, and a hoist adapted to be connected to the yoke to raise and lower it up and down the guides whereby the billet may be lowered into and, removed from the furnace. In one form, Figs. 1 and 2, the apparatus comprises an approach conveyer 14 comprising grooved rollers 20 mounted on side rails 17 and 18, the billets 10 of square section being fed singly edge uppermost on to a train of similar rollers 23 mounted on a carriage 26 which is movable along rails 28 to positions in which it is aligned with the charging apertures of the salt-bath furnace, the conveyer 14 or a delivery conveyer 73: The furnace 43 is provided below each charging aperture with a work-support comprising a pair of sloping guide bars 44 supported from the furnace wall 431 by brackets 45, 46 and fitted with a stop 47 against which the lower end of the billet rests during the heat-treatment operation. Each pair of guide bars carries a slidable work-holder or yoke 55, Fig. 7, comprising side pieces 56, a crossbar 59 adapted to engage the lower end of the billet, feet 60 adapted to engage steps 60<SP>1</SP> on the guides to prevent complete withdrawal of the yoke, and a hook 58 for attachment to a lifting cable 70 which passes round a drum 69 rotatable through rack and pinion gear by a hydraulic cylinder 65. The yoke carries a closure member 71 which closes the charging aperture during the heattreatment operation. The rails 28 are carried by a counterweighted framework 37, 371, 38 which may be swung about a pivot 41 by means of an air cylinder 79 to the position shown in dotted lines in which the billet is received between the side pieces of an elevated yoke, the wheels 27 of the carriage being prevented from leaving the rails by guard rails 30 formed with notches 61 adapted to receive a rocking catch 62 operable by a lever 64 to align the carriage with a charging aperture. The billet is retained on the carriage by a spring-loaded catch 34 which may be depressed to allow the yoke and billet to be lowered into the furnace. When the yoke is raised after the heattreatment has been completed, the catch is depressed by the billet and re-engages behind its lower end. Lifting gear, as shown, may be disposed above each charging aperture, or a single lifting gear movable to different positions may be used. The roller conveyer may be power-operated. In a modification, Fig. 5a, the carriage 85 carrying the roller train is supported by rollers 90 on a single rail 84 formed with alignment notches 87 engageable by a latch 86, and is formed with an arm 91 fitted with a collar 89 which is slidable on a splined shaft 88, the latter being rotatable by an air cylinder to swing the carriage. The guide bars 44 may be inclined at less than 45 degrees to the horizontal, see Fig. 9 (not shown), or may be replaced by brickwork forming part of the furnace wall as shown in Fig. 8. Notches 94 and holes 95 are provided in the brickwork forming the guides to allow circulation of salt in the space 93 behind the billet.