Patent GB-190225023-A (GB)
Title: Improvements in Controller for Electric Motors.
Inventor: KOHLER GUSTAVUS ADOLPHUS EDWAR
Filed: 1902-11-14
Granted: 1903-12-14
Abstract: 25,023. Kohler, G. A. E. Nov. 14. Driving machines by electromotors.-Relates to controlling- mechanism for two or more electric motors, particularly when such motors are to be successively connected to the driving - mechanism. The arrangements are described in connection with printing-presses where it is necessary at first to run the press at a low speed. The press must also be under such control that it can be started and moved only a short distance, and should have an emergency stop so that it can be instantly stopped when desired. The connections and switches are so arranged that the various effects may be produced by pressing one or more of a set of push-buttons. Fig. 16 shows the general arrangement of the motors, clutches, and driving-mechanism, and Fig. 1 is a diagram showing the switches and arrangements of circuits. In the arrangement shown in Fig. 16, the three motors A, B, C are adapted to be connected to the two shafts D, E, which can be connected to form a continuous shaft by a clutch controlled by the lever E<2>. The motor B is connected to the shaft D by a slow-motion gearing B', B<2>, and serves to drive the shaft D at the slow speed. The motor A may be connected by gearing to either of the shafts D, E. When the motor B is running, the armature of the motor A is rotated slowly, but, when current is supplied, it is started up and rotates the shaft at a higher speed, the motor B being disconnected by an automatic clutch. A clutch controlled by the lever D<1> is provided for disconnecting the motor A from the shaft D when required. The motor C is connected to the shaft E by slow gearing, and is also in connection with the armature of the motor A, the connections being controlled by a clutch E<1>. Under this arrangement one shaft may be driven at a low speed and the other at a high speed, or both at low or high speed. In the diagram, Fig. 1, showing the circuit connections &c., the motors A, B, C are controlled from a set of push-buttons 1, 2, 3,4, 5, 6, 7 through the agency of sets of relay and resistance switches. The motor circuits are shown in heavy lines, and the push-button and controlling circuits in lighter lines. Three main double-pole switches X, Y are provided, and also certain auxiliary switches. A safety arrangement is provided for preventing the motors from being started while the resistance of the controller is all or partly out of circuit, or to prevent the speed from being increased. A switch 4 is operated, and controls certain of the currents of the circuits and solenoids. Another switch 8 is provided for a similar purpose. The press may be driven by one small motor and the large motor by moving the levers D<1> to the right ; E' (or E') is also closed, which connects the two sets of pushbuttons in parallel. An automatic clutch for disconnecting the motor B is shown in Figs. 17, 18, 19, and 20. Connected with the worm B<4> is a ratchet-wheel B<5> loose on the shaft. A hollow casing B<9>, keyed on the shaft, fits over the ratchetwheel, and is provided with pivoted pawls B<5>. When the slow motor is driving, the pawls engage the ratchet-wheel. When the high-speed motor is running, the rotation of the casing throws the pawls outwardly into the position shown in Fig. 19, so disconnecting the small motor.