Patent GB-1203918-A (GB)
Title: System for controlling the entry and exit of workpieces into and from a heating furnace
IPC: F27B9/38
Filed: 1969-05-27
Abstract: 1,203,918. Charging and discharging reheating furnaces. WESTINGHOUSE ELECTRIC CORP. 27 May, 1969 [7 June, 1968], No. 26745/69. Heading F4B. A control system for handling steel slabs 40 passing through a reheating furnace 32 associated with a hot strip steel mill incorporates a rollerway conveyer 14 supplying the slabs, a charging machine 18 with a ram 20 pushing the slabs on to the furnace skid rails 36, a discharging machine 60 which lifts a slab from position 45 on to another rollerway conveyer 52 feeding the mill, and a computer 114 fed with the slab widths. The charging machine 18 has two rams 20 supported on rollers 28, each ram having a drive motor (24, Fig. 2) and each having a head 25 comprising teeth 26 suspended by pins 27, whereby on the reverse stroke, the teeth can slide over obstructions. Each ram includes a rack 21 meshing with a pinion gear 30 driven by said motor (24). The discharging machine 60 incorporates a pair of extractors 62 with lift fingers 70 each carried by wheels 72 on a lift platform 76 raised and lowered by cranks 82, 84. Each extractor is reciprocated horizontally by a drive extension 64 supported by rollers 71, 73 and formed with a rack engaged by a pinion 68 on a shaft 69 driven by a motor (92, Fig. 3). The drive from each motor is through a magnetic clutch (95) so that when necessary the extractor can be operated separately. The lift platforms 76 are driven by motors (88, Fig. 3) again through a magnetic clutch (83), reduction gearing 78, rotary members 80 and cranks 86. A television camera 42 enables the first edge of leading slab 40a to be positioned on an index line 44. The exit furnace doors 46 and extractor doors 48 are operated by a motor (100, Fig. 4) driving a shaft (104) on which are wheels (110, 111) over which extend flexible linkages (108, 109) to said doors 46, 48. Automatic control.-The computer 114 is supplied with data equivalent to the width of the slabs and the control system. Fig. 5 includes speed detectors 38, 96, position sensors 39, 98, limit switches 90, 106, a position control 116, a position regulator 128, an automatic initiate 144 and a constant voltage controller 140. The position control 116 passes a signal to a pusher regulator 124 controlling the speed and distance moved by the pusher rams 20. The position regulator 128 initiates operation of the extractor motors 92 through a traverse regulator 130 and receives feedback signals from position sensors 98 which it compares with a slab width signal from the computer. It also operates the lift platform motors 88 through a constant voltage controller 136. The automatic initiate 144 forms part of the pusher control system 112 and may include a clock mechanism initiating the various processes in sequence at desired times. The operator may work through the circuit of this control or through the computer. The constant voltage controller 140 controls the motor 100 operating the doors 46, 48 and is interlocked with the position regulator 128 in order to prevent premature pushing of the rams 20. Manual controls 122, 125, 131 and 142 or semi-automatic controls 120 and 129 are provided in case the operator wishes to change from automatic operation.