Patent GB-472018-A (GB)
Title: Improvements in methods for rolling metal
IPC: B21B39/14
Filed: 1936-12-31
Abstract: 472,018. Rolling. COLD METAL PROCESS CO. Dec. 31, 1936, No. 35866. Convention date, Oct. 23. [Class 83 (iv)] In rolling a strip back and forth between rolls 15 by reversible pulling and braking coilers 21 at each side, the trailing end of the strip passes right through the roll but is gripped by pinch rolls 63, and on reversal, is fed back by them through the mill, the pinch rolls then being separated automatically during the remainder of each pass, while the coiler now applies a pull to the strip, Adjustable side guides 34 and top and bottom guides are also provided, and the strip passes over a driven scale removing roll 24. A pair of side guides 34 on each side are automatically moved to provide a parallel guiding throat on the entry side of the mill and a tapered guide throat on the exit side. The flattening rolls serve to straighten the strip end so that it is directed into a coiler 21 of a furnace 20 on one or other side of the mill. Initial hand adjustment of the guides is provided by disconnecting the dog clutches 54 and operating hand wheels 49 and 40 and thereafter the adjustment to parallel lead-in and tapering exit is automatic after each pass, either by means of a friction clutch 53 operating the shaft 33 from the reversal of the mill motor, or by pneumatic cylinder and piston, Fig. 1a. The feed and pinch rolls 63, Figs. 2 and 4, on each side of the mill are combined in one bearing block with end-flattening rolls 64, 65 whereby the strip end can be received into the coiler 21, these rollers being raised and lowered automatically or manually by pneumatic cylinders 62 and 69. Fig. 8 shows the automatic operation of the pinch roll which when the slab is thick are not required and are withdrawn when the roll pass is set, e.g. at ¥" or more the limit switch 114 closing its contact to energize magnet 111 and move the fluid valve 107 to supply fluid from a reservoir to cylinders 78 on both sides of the mill to raise the upper pinch rolls. After the strip has been rolled it is thin enough to require feeding by the pinch rolls, the switch 114 closes its upper contacts to energize magnet 110 operating valve 107 to exhaust cylinder 78 so that its piston lowers the pinch rolls on to the material and the pinch roll will grip the material for the next pass from right to left. The workman operates the handle of the controller 105 to the left whereupon motor 103 drives the rolls 15 which roll the strip from right to left. The movement of the controller also energizes a dashpot delayed relay 117 bridging contacts 117a to energize magnet 113 operating valve 109 admitting fluid to cylinders 62 to lift the pinch roll on the entering side clear when the rolls 15 have gripped the strip. After a longer delay contacts 117b are bridged maintaining the energizing of magnet 113. When the leading end of the strip has emerged from the mill on the exit side, passed through the pinch rolls and made one turn about the coiler 21 the relay contacts 117b are bridged, maintaining the circuit to magnet 113 &c., and now energizing magnet 112, shifting valve 108 so that cylinders 82 now raise the other pinch rolls clear, both sets of pinch rolls now being inoperative. Valves 109, 108 also raise stop motion roll 92, Fig. 7, so that if the strip breaks, it contacts with roll 90 whereupon rod 98 lifts the contact 101 to open the circuit for the relay 106 to stop the mill motor 103. When the pass is completed the controller 105 is returned to neutral so that the trailing end of the strip stops in the space between the mill rolls and the exit pinch rolls. The relay 117 is then de-energized, to de-energize magnets 112, 113 exhausting cylinders 82 and dropping pinch rolls to each side to stripgripping positions. At the same time the cylinders 94 exhaust through check valves 118 by the weight of the roll 92 and chocks 93. For the return pass the controller 105 is reversed energizing relay 120 which at the right time lift the pinch rolls when the strip is engaged by the coiler. The cycle is repeated until the strip is thin enough when the strip is wound up on a coiler beyond the furnace and the top roll 15 is screwed up. The limit switch 114 closes its lower contacts and operates valve 107 to admit fluid pressure again to cylinder 78 to lift both pinch rolls up to allow flat rolling of the next plate. The side guides of Fig. 1a are automatically controlled as the controller 105 is shifted, e.g. to feed the material from left to right whereby it closes contacts 121 energizing magnet 122 of fluid valve 123 delivering fluid pressure to the inner ends of cylinders 71 on the left-hand exit side of mill and to the other ends of cylinders on the right-hand side of mill thus closing in the ends of pivoted guides 36 on the entering side and opening the ends of the pivoted guides in the exit side. On reversal of the direction of rolling the controller 105 bridges contact 124 energizing magnet 125 to shift valve 123 to operate the guide cylinders in the opposite direction. Top and bottom pivoted guides and strippers 29 and 26 are also provided. Specification 465,745 is referred to.