US1782708A - Elevator-control system - Google Patents

Description

Nov. 25, 1930. BOUTON 1,782,708

ELEVATOR CONTROL SYSTEM Original Filed April 28 1935 u n T WITNESSES tain 9 motor, ha

Patented Nov; 25, 1930 time sarssl PATEhIT err-ice EDGAR IE. EQUTQN', OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC 6c MANUFACTURING VANIA.

Application filed April 28, 1925, Serial No. 28,343.

My invention relates to motor-control systems and it has particular relation to such systems of control as are employed in connection with elevators, hoists and similar a machines.

One object of my invention is to provide means for improving the speed regulation of an elevator motor, particularly during low-speed 0 oration.

Another 0 ject of my invention is to provide means for securing accurate stopping of the elevator independently of load conditions.

Other objects of my invention wiliappearin the following detailed description.

In accordance with my invention, I employ a compound wound generator or booster having its armature winding in circuit with themo'tor armature winding under all operating conditions. This system is peculiarly adapted for elevator systems employing rheostatic control and in which speed control is normall obtained by means of resistors connecte respectively in series with, and in shunt relation to the motor armature. Theauxiliary generator is rovided with a cumulative compound series fieldwinding that is efiective, particularly during low-speed operation, to maintain a predetermined voltage on the motor armature and to insure proper speed regulation thereof.

My invention finds particular application in connection with systems of control of the type that is set forth in Patent No. 1,526,314

of E. M. ,Bouton and F. E. Lewis, datedFebw'hIi ch, d1 n i l e 1 is a 'agrammatic re resentation r g y of circuits and apparatus em invention.

, Figs. 2 and 3 represent, schematically, cermain connections employed in the operation of the system shown in Fig. 1.

Referring particularly to Fig. 1, ashunt vmg an 1 andashunt crating periods.

COMPANY, A. CORPORATIOH OF PENNSYL- mhvaronconrnon srs'rma Renewed August 12, 1927.

field-magnet winding 2, is connected to a source of energy comprising line conductors 3 and 4. The motor may be operatively connected, for example, to an elevator car 26 and maintained at rest in its inoperative position by means of an electromagnetic brake 5. An auxiliary generator, having an armature 6 and series and shunt field-magnet windings 7 and 8, respectively, 'hasits arma ture 6 connected in clrcuit with the elevator motor armature 1. The direction of rotation of the motor is controlled by reversing switches 9, 10, 11 and 12, in accordance with well-known practice, and a line'switch 13 is also employed in a familiar manner.

A starting and speed-regulating resistor,

having a plurality of sections 14, 15, 16 and 17, is connected in circuit, with the motor armature 1, resistor section 17 being connected in shunt relation to the armature and series relation with the armature.

A switch 18 of the normally closed type is adapted to control the circuit of the shunt resistor 17, and, similarly, the normally open switches "19 and 20 are adapted to shunt resistor sections 14 and 15. during the accelerating period. During full speed operation, the auxiliary generator field winding 7 is shunted by a. resistor 16 through a switch 21. -A double-pole, double-throw switch 22 is provided for maintaining the armatures 1 and 6 in' circuit In case of emergency, this switch may be opened to disconnect the aux iliary trolling the emergency switc 22. The auxiliary generator armature 6 is driven by any tor 24.

.The motor armature 1 is operativelyconnected in the usual manner to a driving sheave 25 for operatingthe elevator car 26.

A car. switch 27, which is located in the elevator car, provides means for controlling the direction of motion and the l vator. Auxiliary leveling means, comprising- switches 28 and 29, which are mounted on during all op-' generator. A knife switch 23, which is located on the car, is em loyed .for conspeed of the elethe car to cooperate with a plurality of cams 30 that are mounted in the hatchway adjacent to each floor, may be employed in the usual manner to control the stoppin of the elevator independently of the skill o the car operator.

The success of the leveling device depends I upon its ability to maintain a predetermined low operating car-speed, independently of thecarload, as is well understood, and my invention finds particular application in connection with such operation. Upon the actuation of the car switch 27 in a clockwise direction, a circuit is established for the operating coils of reversing switches 10 and 12 and line switch 13, said circuit being established through car switch contact members 31 and 32 and conductors 33 and 34, in accordance with a familiar practice.

The main circuit for the motor armature 1 extends from line conductor 3 through switch 13, reversing switch 12, resistors 14, 15 and 16, field windin 7, switch 22 (which now occupies its leftand closed position), armatures 6 and 1 and reversing switch 10 to line conductor 4. A portion of the starting current traverses an armature-shunt circuit comprising resistor section 17 and switch 18,

thereby afiording a minimum operating speed of the armature 1 as in the case of the abovementioned patent. It is recognized, however, u

voltage from line conductors 3 and 4 and the voltage derived from the auxiliary armature 6 are in the same direction, independently of the direction of rotation of the motor armature 1.

Upon an increase of load, the current -traversing the armatures 1 and 6 also traverses the series field-winding 7 and efi'ects a corresponding increase in the excitation of the auxiliary generator, thereby increasing theyoltage of said generator by the required amount. used for the specific purpose of maintaining suitable speed regulation at low car speeds, it is ossible'to provide therefor a field winding havin suitable ampere-turns corresponding to t e desired operating speed.

When full car-speed is desired, the resistors lto 17 are excluded in the customary manner and, in addition, the series field-winding 7 is shunted by the closure of switch 21, so thatv during full speedoperation, there is a reduction in the value of the electromotive force of generator armature 6 that is applied to motorrarmature 1. This regulating efiect Since this generator is.

cam 30 in accordance with a familiar practice, to maintain reversing switches 10 and 12 and line switch 13 closed while approaching the floor. By this means, a slow operatlng s eed is maintained which corresponds to the rst operating point of the car switch 27, since switch 29 functions to shunt the car switch-contact members 31 and 32 and maintain the previously mentioned operating circuit, comprising the conductors 33 and 34, When the car has moved downward, and is substantially flush with the corresponding floor-level, the leveling switch 29 assumes the illustrated inoperative position. If, for any reason, the car should overtravel, switch 28 will close to eifect a reversal of motion and return the elevator to the desired position.

It is found, however, that under normal operating conditions the car-speed will be so controlled, in accordance with the load, that it will always stop even with the floor without the necessity of a reversal of motion.

To manually efiect upward movement of the car, the car switch 27 is actuated in'a counter-clockwise direction to energize contact member 35 and complete a circuit through conductors 34 and 36 to energize reversing switches 9 and 11 and line switch 13. Low-speed connections are thereby effected for the upward direction of travel, and current traverses both the armatures 1 and 6 in a direction reverse to that previously traced. Therefore, the voltage derived from the auxiliary generator 6 is in the proper direction to boost the voltage impressed on the motor armature 1 in accordance with an increase in the load imposed thereon.

In the event of an overhauling load, that is, when the load in the elevator car tends to drive the armature 1 and cause a reverse current or current of regeneration to flow though field winding 7, the voltage impressed by the generator armature 6 is reduced to compensate for the load efiect and regulate the motor speed accordingly.

It has been deemed unnecessary to further illustrate and describe the usual means for efiecting variable-speed control of the elevator, all of which is under the control ofthe car switch 27,,in accordance with a'. familiar practice, and which forms no' part-of my that my invention shall be limited only in accordance with the scope of the appended claims.

I claim as my invention:

1. The combination with an elevator and a hoisting motor therefor, of means for controlling the speed of said motor, and an -auxiliary source of energy for modifying the effect of said controlling means, manually operable means'for controlling the motor circuit, and means controlled by the movement of the elevator for controlling said auxiliary source of energy. I V

'2. The combination with an elevatorand a hoisting motor therefor, of rheo'static means for controlling the voltage of the motor armature, an auxiliary source of energy for regulating the voltage applied to said motor armature, manually operable means for controlling said rheostatic means, and means operable in accordance with the movements of the elevator for controlling said auxiliary source of ener 3. The coml ihaiton' with an elevator and a hoisting motor therefor, of means for controlling the speed of said motor, an auxiliary source of energy comprising a compoundwound generator for modifying the efi'ect of said controlling means, manually operable means for controlling the motor circuit, and means controlled by the movement of the elevator forcontrollingsaid auxiliary source of energy.

24. The combination with an elevator and a hoisting motor therefor, of rheostatic -means for controlling the voltageofthe motor armature, an auxiliary generator having a cumulative compound field-winding for regulating the voltage applied to said motor armature, manually operable means for controlling said rheostatic means, and means operable in accordance with the movements of the elevator for rendering said auxiliary generator efiective to secure accurate stops of said elevator.

5. The combination with an elevator and a hoisting motor therefor, a rheostatic means for controlling the voltage of the motor armature, an auxiliary generator having a cumulative compound field-winding for regulating the voltage applied to said motor armature, and means for excluding the series field-Winding of said generator during highspeed operation of the velevator.

6. In an elevator-control system for multispeed elevators, an elevator, a hoisting motor, a source of energy therefor, means for selectively connecting said motor to said source for low-speed and high-speed operation, means for said motor constant under varying load conditions comprising an auxiliary source of enmaintaining the speed of t ergy, means for connecting said auxiliary source of energy to said motor to increase or decrease the total energy supplied to said motor in accordance with variations in the load on said motor, and means responsive to said high-speed connecting means for diminishing the effect of said auxiliary energy source during high-speed operation.

The combination with an elevator and a hoisting motor therefor, of a source of electrical energy, rheostatic means for selectively controlling the voltage from said source to the motor armature for low and highspeed operation, an auxiliary generator havmg a cumulative compound field winding,-

means connecting the armature and series field winding of said generator in series relation with the armature of said motor whereby the total energy supplied to said motor will vary in accordance with the load on said motor, and means operable by said high-speed connecting means for shunting said enerator series field winding.

8. i ii an elevator-control system, an elevator operable past a floor, a hoisting motor, a source of energy therefor, means for regulating the speed of said motor under varying load conditions comprising an mo auxiliary source of energy to increase or decrease the total energy supplied to the motor in some direct proportion to the load on said motor and means, operable in accordance with the position of said car with respect to said floor'and effective, when said elevator is a predetermined distance in advance of said floor, to connect said motor to said source and said auxiliary source, and efi'ective, when said elevator reaches said floor, to disconnect said motor from said source and said auxiliary source.

9. In an elevator-control system, an elevator operable past a floor, a hoisting motor, a source of energy therefor, means for maintaining the normal speed of said motor constant under varying load conditions comprising a generator, means for driving said generator, means for causing the output of said generator to increase or decrease in accordance with the load on said motor, and means operable in accordance with the position of series field winding, means for driving said armature, means 0 erable, in accordance .with the position 0 said elevator with res set to said floor and effective when said e evator is a redetermined distance in advance of saif floor, to connect said series field winding and said armature in series =relation with said motor and said source,

and to connect said shunt -field winding to said first named source of energy, and efieotive, when said elevator reaches said floor, to disconnect said motor from said source and. said auxiliary source and to disconnect said shunt field winding from. said source, and means for varying the output of said generator at will.

11. In an elevator-control system, an ele-- vator operable past a floor, a hoisting motor, a source of energy therefor, means for mamtaining the normal speed of said motor constant under varying load conditions comprising anauxiliary source of energy to increase or decrease the total energy supplied to the motor in accordance with the load on said motor, means for variably determining the constant speedof said motor, and means, operable in accordance with the position of said car with respect to said floor and efiective, when said elevator is a predetermined distance in advance of said floor, to connect said motor to said source and said auxiliary source, and efiective, when said elevator reaches said floor, to disconnect said motor from said source and said auxiliary source.

. 12. In a motor-control system for an elevator; a hoisting motor; a main source of power for said motor; an auxiliary source of power for said motor efiective to supply a component of voltage proportional to the load on said motor; and a controller for said motor, including means operable to control said main source of power to cause said motor to operate at a, low and high speed, means responsive to operation of said. con

- troller to cause said motor to operate at a low speed for connecting said motor to said source in series with said auxiliary source to pro vide a slow speed for said motor the value of which is independent of the load on said motor, and means responsive to operation of said controller to cause high-speed operation or said motor to render said auxiliary sour ce ineflective to supply said proportional component of voltage to said motor.

13, In a motor-control system for an elevator; a hoisting motor; a main source of power for said motor; an auxiliary source of power for said motor comprising a generator having a series winding efiective to supply a component of voltage proportional to the load on said motor; and a controller for said motor, including means operable to control said main source of power to cause said motor to operate at a low and a high speed, means responsive to operation of said controller to cause said motor to operate at a low speed for connecting said motor to said source in series with said auxiliary source to provide a slow speed for said motor the value of which is independent of the load on said motor, and means responsive to operation of said controller to cause high-speed o eration of said motor to render said auxan auxiliary source of POWGIlfOI' said motor effective to supply a component of voltage proportional to the load on said motor; and a controller for said motor, including means to complete and interrupt low and high-speed circuits for said motor, means responsive to completion of a low-speed circuit for connectmg said motor to sa (1 mam source in series with said auxiliar source to provide a low operating speed 0 said motor the value of which is independent of the load on said motor, means, responsive to completion of av high-speed circuit to render said auxiliary source inefiective to supply said proportional component to said motor, and additional means to control said'low-speed circuit, said additional means being eiiective to complete said low-speed circuit when said car reaches a oint a predetermined distance in advance 0 said floor and to interrupt said circuit when said .car reaches a point substantially level with said floor. I

' 15. In a motor-control system for an elevator operable past a floor; a hoisting motor; a main source of power for said motor; an auxilia source of power for said motor comprising a generator having a series wind-' ing efiective to supply a component of voltage proportional to t e load on saidmotor; and a controller for said motor, including means to complete and interrupt low and high-speed circuits for said motor, means responsive to completion of a low-speed circuit for connecting said motor to said main source in series with said'auxiliary source to-provide a low operating speed of said motor the value of which is independent of the load on said motorg means responsive to completion of a high-speed circuit to der said auxiliary source ineflective to supply said roportional component to said motor, and a ditional means to control said low-s eed circuit, said additional means being e ective to complete said low-speed circuit when said car reaches a point a'predetermined distance in advance of said floor and to interrupt said circuit when said car reaches a point substantially level with said floor.

m 16. In a control system for an elevator operable past a floor; a hoisting motor; a main source of power for said motor; an auxiliary source of power for said motor efi'ective to sup ly a component of voltage proportional to t e load on'said motor; and a controller for said motor, including leveling mechanism to eiiect the stoppage of said car substantially level with said floor, said levelin mechanism comprising means efiective w "en said car reaches a oint a predetermined distance in advance 01E said floor to connect said motor to said main source in series with said auxiliary source to provide a slow operating speed of said motor the value of which is independent of load and effective when said car reaches a point substantially level with said floor to disconnect said motor from both of said sources. v,

17. In a control system for an elevator opao erable past a floor; a hoisting motor; a main source of power for said motor; an auxiliary source of power for said motor com rising a generator having a series winding e ective to supply a component of voltage ropora5 tional to the load on said motor; an a controller for said motor, including leveling mechanism to effect the st page of said car substantially level with said fioor, said leveling mechanism comprising means efiective 40 when said car reaches a point a redetermined distance in advance of sai floor to connect said motor to said main source in series with said auxiliary source to provide a slow operating speed of said motor the value of which is independent of load and effective when said car reaches a int substantially level with said floor to disconnect said motor from both of said sources.

In testimony whereof, I have hereunto subscribed my name this 20th dfiof A ril, 1925.

. EDGAR 30%TON.

Images