Patent GB-427748-A (GB)
Title: Improvements in or relating to control systems for electrically driven elevators
IPC: B66B1/08
Filed: 1933-10-27
Abstract: 427,748. Master control of D.C. motors; actuating controllers. WESTINGHOUSE ELECTRIC & MANUFACTURING CO., East Pittsburg, U.S.A.-(Assignees of White, K. M. ; 47, West Main Street, Mooresville, Indiana, U.S.A.) Oct. 27, 1933, No. 29840. Convention date, Oct. 29, 1932. [Class 38 (iii)] Varying E.M.F.-A controlsystem for an elevator motor comprises a rheostat adjusted by a control motor which is started to adjust the rheostat for decelerating the elevator by means responsive to the operation of stopping means for the elevator motor, and to the position of the elevator car, means responsive to the operation of the control motor being provided, whereby the control motor is stopped. For upward movement of the elevator, gate switch g, Fig. 2 and door switches d are closed, and the car switch cs is moved clockwise. Relays 40, 42, and 80U are energized and forward contactor 1 and relays 6, 25 operate to connect potentiometer resistance P, Fig. 1, across the supply, energize a relay 34, and release a brake Bw. The relay 34 closes the circuit of a relay GR3 which changes tappings on a potentiometer CR to increase the effect of a regulating generator RG. The field GF of the Ward Leonard generator G for the elevator motor M is energized from a tapping 94 of the resistance D and the motor M operates at slow speed. Relays 25 and 34 complete the circuit of a control motor RM through resistance R1, R3, and this motor drives a cam-shaft controller to close switches RH9 and RH3, the latter connecting tappings 133 and 94 of the resistance P, thereby increasing the voltage of the generator G and the elevator speed. Further operation of the cam-shaft controller closes a switch RH10 and opens a switch RH2, the latter disconnecting the potentiometer tapping 94 thereby further increasing the speed. Still further operation of the cam-shaft controller opens a switch RH1, and thereafter switches RH3, RH5, and RH7, also switches RH6 and RH12 are closed. The opening of switch RH5 stops the control motor RM, and the opening of switch RH3 and the closure of switch RH12 causes the voltage of potentiometer tapping 140 to be effective, this condition being maintained if the cam-shaft controller overruns by closure of a switch RH13. The opening of switch RH6 causes a self-holding relay GR6 to close thereby connecting potentiometer tappings 140, 141 to apply almost full line voltage to generator field, and give the elevator its maximum speed, and also connect a regulating generator RG directly in series with the generator field GF. Previously the generator RG is connected in series with the generator field GF by means of a potentiometer CR. The generator RG has a field RSF in series with the elevator motor armature and a field RGF energized in accordance with the difference between the voltage applied to the generator field GF and he voltage of a tapping on a potentiometer 'M connected across the motor armature. The regulating generator RGF thus causes he motor to drive the elevator at a speed onforming to the desired characteristic. The elay GR6 also energizes a relay 55 which inserts resistance R2 in circuit with the control motor PM. The elevator continues to run at the maximum speed until the operator eturns the car switch Cs just before the car eaches a floor at which it is desired to stop, whereupon the relay 80U is de-energized to Le-energize relay 25. The coil of inductor elay 4L is thereby energized, and when the orresponding inductor plate passes it, contacts 4UL are opened to de-energize relay GR6. This transfers the generator field GF to poteniometer tapping 140 to decrease motor speed, and also energizes inductor relay 3L. When he corresponding inductor plate passes, conacts 3UL are opened to de-energize relay GR4. This energizes inductor relays 24, 1L, .nd starts the control motor RM with resisances R2, R3, in circuit. The consequent operation of the cam shaft controller opens ontacts RH12, and closes contacts RH13. Further operation closes contacts RH5, RH7, .nd opens contacts RH6. The closing of ontacts RH7 makes a maintaining circuit or contactor 1 and relay 6 if a cage limit witch ULS opens. If the control motor has not started to decelerate the car, this limit witch is operative. Further operation of he cam shaft controller causes contacts RH13, RH14 .... to close in sequence, and he generator field GF is reduced in a large number of small steps. When the last of the eries of switches RH14.... closes, RH8 opens to stop the control motor. However, at this time the car is moved to a position to operate the inductor relay 2L and close ontacts 2UL. This completes another circuit or the control motor RM by opening relay GR3, which also short-circuits the gate switch elay 40, so that the gates may be opened. )peration of the cam shaft controller now loses RH29 to reduce the generator field, and thereafter closes switch RH30 to effect urther deceleration. The cam shaft conroller then opens RH9 and RH30, and closes RH31, thereby stopping the motor RM. Vhen the inductor relay 1L is operated, ontactor 1 and relay 6 are de-energized to disconnect the generator field and apply the brake, the motor RM being started at the ame time with resistances R1, R2, shortircuited so that cam shaft controller is moved at a higher speed to its original starting posiion, whereupon a switch RH10 opens and tops the motor RM. If a run for one floor only is required, the car switch Cs is returned before RH6 is closed so that relays 80U and 25 are de-energized and the maximum speed s limited, as the relay 55 is thus kept denergized and the potentiometer tapping is determined by a connection 140y. Also resistance R2 is kept short circuited for accelerating so that the cam shaft controller speed is the same as for longer runs, but for deceleration resistance R3 only is in circuit. As shown in Fig. 3, the cam shaft controller comprises a set of adjustable cams 14, clamped on the operating shaft by screws 19, and a set of non-adjustable cams 15 fixed side by side in proper relationship by positioning pins. The end cams of the set 15 are connected by pins to members 38 attached by pins 39 to the operating shaft driven through gearing by the pilot motor RM.