Patent GB-441941-A (GB)
Title: Improvements relating to control systems for electrically actuated rolling mill screw-down gear
IPC: B21B37/60
Filed: 1934-08-29
Abstract: 441,941. Rolling. LANGLEY, E. H. M., 7, Grosvenor Road, Urmston, GEORGE, H. N., Rockford, Lonsdale Avenue, Davyhulme, both in Lancashire, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Aug. 29, 1934, No. 24878. [Class 83 (iv)] [See also Group XXXVII] A motor, operating rolling mill feed or screwdown mechanism is under the control of a series of sequence relays R1-R13 adapted when actuated to cause screw down movement of the gear through predetermined amounts, the operating coils of alternate relays R1, R3 ... being associated with one control bus-bar 26 and those of the intervening relays with another control bus-bar 25, the said control bus-bars being automatically energized in turn by alternate passes of the material 13. A throw over switch 23 effective to cause the alternate energization of the control bus-bars is operated by means of a coil 22 controlled by a relay 18, 21 under the control of a light sensitive relay 16, 17 and is arranged to be actuated on alternate passes only. The circuit through the contacts of the throw-over switch is kept open until a complete pass of the material has been made, by means of normally closed contacts opened by energization of the coil 22 of the throw over switch. Energization of a sequence relay closes contacts in the circuit of the coil of the next relay in the sequence and trips the preceding relay. It also closes a corresponding motor contact M1, M2 ... which completes the circuit of a coil 28 closing the motor circuit for screw-down operation. The motor thus effects screw down adjustment and is stopped by means of a corresponding limit switch L1, L2 ... operated by corresponding cam member T1, T2 ... on a drum driven by the motor. The cam members T1, T2 ... are adjustable as to their angular positions on the drum. When the sequence of screw-down movements is completed and the contacts M13 are closed by the relay R13, a coil 30 is energized to connect the motor for reverse operation until a limit switch L13 is operated at the end of the screw-up movement. As the drum carrying the cam members makes several revolutions during the screw-down movement the contacts L13 are shunted by closed contacts 32 on a drum 34 geared to the main drum to make one revolution only, the contacts 32 being opened by a cam 33 only at the end of the screw-up movement. The relay 29 is energized to cause slow down prior to the completion of the screw-up movement by a switch N13 operated by a cam 36 on the main drum and a switch 35 operated by a cam on the drum 34. The relay R1 is set for a fresh screw-down operation by means of a relay R14, the contacts C14 being tripped out when a coil R19 in parallel with coil R1 is energized. A lamp 42 is arranged to indicate when the apparatus is reset for screw-down operations, the lamp circuit being controlled by a contact 44 operated by the main drum, and a contact 43 operated by the drum 34. If the sequence is to include screw-up movements selector switches P6 ... are arranged to connect the motor contacts M1, M2 .. to the contactor coil 30, as shown in the case of motor contacts M10.