GB418296A - Improvements relating to furnaces - Google Patents

Abstract

418,296. Metal - heating furnaces. ARNOLD, C., 11, Southampton Buildings, Chancery Lane, London.-(Foundry Equipment Co. ; Cleveland, Ohio, U.S.A.) Feb. 13, 1933, No. 4387. [Classes 51 (i) and 51 (ii).] Charges, conveying; doors.-In a metalheating furnace having a step-by-step conveyer comprising fixed rails alternating with moving rails adapted to be raised and lowered and reciprocated horizontally, the movements of the latter rails are effected by a single driving element which alternately engages gearing for raising and lowering the rails and gearing for moving them to and fro. As shown, the moving rails 26 are carried on cross beams 27 mounted on posts 28 which extend through the furnace bottom 3 and are adjustable vertically in sockets 31<a> secured on a girder framework 30, 31. The slots 38 in which the posts 28 operate are provided at both upper and lower ends with sealing devices comprising fixed slotted plates 39, 41, over which are moved, as the posts 28 travel longitudinally of the furnace, sealing plates 40, 42, the latter being imperforate except for an aperture to permit passage of the post 28. The vertical and horizontal movements of the frame 30, 31 are derived from a shaft 52 driven through reduction gearing from a motor 50 and having secured thereon a mutilated pinion 54 which engages alternately with pinions 55, 57, Fig. 21, on shafts 56, 58, the latter respectively effecting the raising and lowering and the horizontal reciprocation of the frame 30, 31. The shaft 56 is connected by cranks 61 and connecting rods 62 to bell-crank levers 65, Fig. 7, rigidly mounted on a rock shaft 64 and carrying rollers 69 which engage wear plates 70 on the underside of the girders 31 and effect the raising and lowering thereof as the shaft 64 is rocked. In order to provide for lifting the girders 31 throughout their entire length, the bell-cranks 65 are connected to sectional pull rods 66 to which are attached at intervals further bellcranks 65<a> also carrying rollers 69<a> engaging the undersides of the girders 31. The shaft 58 is connected through crank 84 and connecting rod 85 to an arm rigid on the rock shaft 88, the latter carrying arms 90 supporting blocks 92 which effect reciprocation of the frame 30, 31 by engagement in driving blocks 94 mounted on the girders 31. To prevent any overlap of the vertical and horizontal movements, there are secured to the pinions 55, 57, discs 95, 96 having oppositely disposed notches 95<a>, 96<a>, these discs being displaced by 90‹ from each other in order that rollers 104 on the ends of a rocking beam 102 may, by engagement in one of the notches 95<a>, 96<a>, maintain stationary the pinion 55 or 57 which is not in mesh with the driving pinion 54. The rails 26 of both the fixed and moving parts of the conveyer are formed of longitudinal sections connected together by tongue and slot connections to permit expansion and contraction. The furnace is fired by burners 16 disposed in staggered relationship along the two side walls, these walls being formed with oppositely arranged vertical flues 14, 15 which communicate at their lower ends with the space B below the conveyer and at their upper ends with the burner ports 14<a> and the atmosphere respectively. This arrangement effects a re-circulation of the hot gases through the working chamber A and the space B below the conveyer, the excess gases passing out through the damper-controlled outlets 19 at the upper ends of the flues 15. The furnace chamber A has, at the charging end, self-closing pivoted doors 49 and, at the discharging end, a vertically sliding door 106 which is actuated, through a segment 109<a>, connecting rod 112, and crank 113, by a motor 115; the latter is started and stopped by a switch operated automatically by the end of the moving part of the conveyer or by an article thereon.