Patent GB-360445-A (GB)
Title: Improvements in electric controllers for printing presses or the like
IPC: H02P5/68
Filed: 1930-05-09
Abstract: 360,445. Master control of several D.C. motors. CLINE, A. J., 111, West Washington Street, Chicago, U.S.A. May 9, 1930, No. 14339. [Class 38 (iii).] Field and armature control varying E.M.F. ; non-regenerative braking.-In a printing press in which the different printing units 1 .. 7, Fig. 1, and the folders F1 F2 are each driven by separate motors, 14, 15 switches 22 are provided for associating one of two master control panels 11, 12, with one of the folder motors, and a selected group of printing motors, to effect simultaneous control of all the motors forming a complete group. The invention is described in connection with arrangements for " inching," accelerating, decelerating, stopping, and dynamic braking. A motor 78, Fig. 3, drives a generator, the field 79 of which is regulated by an arm 101 driven over a face plate controller 31 by a motor 106, to vary the voltage applied to a field of the motors 14, 15. For inching a button 88 is pressed energizing a coil 61 and closing switches 62 to place the motors 14, 15 across low-voltage mains 26. To run the motors up to speed a button 89 is pressed energizing a coil 49 and closing a switch 51 which supplies a forward, running field 117 of the motor 106. The arm 101 thus moves to the left and carries out the control in the following order. First it energizes the contactor 61 to connect the motors to the low-voltage supply 26, then a contactor 58 to connect the motors across a high-voltage supply 25. Afterwards it energizes accelerating relays 64 in turn, to cut out armature resistances 73, 74, 75, and finally it gradually connects a resistance 126 in the generator field 79. The contactors 61, 58 are mechanically and electrically interlocked to prevent both closing at the same time. On reaching a designed limit the arm 101 engages an adjustable contact 119, to de-energize the coil 49 and stop the motor 106. If the button 89 is released with the arm 101 in contact with a segment 128, a relay 41 is energized to supply current to one or more of the accelerating relays 64, depending on the position of a dial switch 57. Thus the motors receive high torque for starting, and the speed is automatically limited by a relay 68, which is connected across the armature, and which at a certain speed energizes a relay 69 to connect a braking resistance 130 across the armature ; at the same time the armature resistances are reinserted. When a decrease switch 87 is closed, a contactor 52 is energized to close the current of a backward-running field 131 of the motor 106, so that the arm 101 is returned to its " off " position at which a limit switch 129 is opened to disconnect the motor 106. When a stop button 86 is pressed or an overload relay operates, a contactor 34 is closed to de-energize a relay 37, the opening of the upper contacts 38 of which disconnects the motors 14. At the same time contacts 35 are closed, to energize a contactor 66 which places a braking resistance 134 across the armatures of the motors 14, and contacts 100 are closed to strengthen the generator field 79. The closure of additional contacts 35 keeps the contactor 52 energized to ensure the return of the cam 101 to its " off " position. The relays 37, 34 are so interlocked that the arm must return to the " off " position before the press can be again operated. In order that the motors cannot be transferred from the high to the lowvoltage main until the back electromotive force has fallen to the value of the low-voltage mains, a one-way conducting device 135 is connected in circuit between the motors and the low-voltage line through the coil of a relay 137 which controls the currents of the high- and low-voltage relays 58, 61. A paster button 84 is provided upon closure of which a relay 43 is energized to close the circuit of the relay 52 which returns the master switch arm 101 to a position determined by a paster dial switch 56. Specification 340,228 is referred to.