US1870410A - Automatic elevator control system - Google Patents

Description

g- 9, 1932- R. P. HIGBEE 1,870,410

AUTOMATIC ELEVATOR CONTROL SYSTEM Filed June 22, 1927 759 O/her WITNESSES: INVENTOR 4 5 W Rag P. Hfgbee v ATTORNEY Patented Aug. 9, 1932 UNITED STATE PATENT OFFICE RAY I. HIGBEE, 0F WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION CF PENNSYLVANIA AUTOMATIC ELEVATOR CONTROL SYSTEM Application filed June 22,

My invention relates to control systems and it has particular relation to systems of control for elevators, hoists and similar apparatus.

An object of my invention is to provide a control system for motors, wherein the motor may be stopped at predetermined points in its movements in response to the operation of a series of switches.

Another object of my invention is to provide a control system for elevators, wherein a plurality of elevators in a bank may each be started by an attendant on the car and stopped automatically in response to the operation of push-buttons operated by the persons desiring to use the car.

Another object of my invention is to provide a control system for elevators, wherein the starting of the car is under the control of an attendant on the car until the car attains a predetermined speed, and thereafter the elevator is under the control of passengeroperated push-buttons.

Another object of my invention is to provide a control system for elevators, wherein the car is automatically stopped by passengeroperated control means and, until the elevator reduces its speed below a predetermined value, the attendant on the car may not control the car to cause it to attain its high-speed operation.

Another object of my invention is to provide a control system using an inductor-relay system for stopping the car in response to the operation of passenger-controlled push-buttons, wherein the inductor plate may be retired from co-operative relation with the relay when it is desired to operate the elevator independently of such push-button control.

Another object of my invention is to provide a control system for elevators, wherein any of the cars may be stopped automatically in response to the operation of passengeractuated push-buttons, and wherein a floor selector is operated by a pilot-motor in correspondence to the movements of the elevator in its shaft.

My invention will be described with reference to the accompanying drawing, wherein The single figure is a diagrammatic illus- 1927. Serial No. 200,573.

tration of the circuits, relays and other electrical apparatus for two elevators, using inductor relays for selecting the stops to be made by the car.

Referring to the drawin the system herein shown comprises varia le-voltage equipment of the VVard-Leonard type, for an elevator car, comprising a generator G directly coupled to a driving motor M, illustrated as a shunt-wound motor having an armature M and a shunt field winding MF connected directly across the line conductors L1 and L2, by way of conductors 6 and 7 respectively. The generator G is of the compoundwound type, comprising an armature G, a series field winding GSF and a shunt field winding GF. The armature and the series field winding of the generator G are connected in a loop circuit with the armature EM of the elevator hoisting motor EM by way of conductors 8 and 9, respectively. The elevator motor EM is provided with a shunt field winding EMF connected to conductors 6 and 7 and has its armature EM directly coupled to a hoisting drum D. An elevator car C is shown connected to a hoisting cable CA, which passes over the hoisting drum D to a counter weight CW. Only one elevator car is illustrated, in order to to simplify the drawing, but it is obvious that each of the other cars in the bank will be similarly connected and provided with the motor-generator-motor hoisting equipment described.

In order to control the direction and speed i of the car, an up direction-switch 1 and a down direction-switch 2 are shown respectively connected to a pair of push-buttons U and D, which are mounted upon the car C. The direction-switches 1 and 2 control the voltage supplied to the generator shunt field winding GF through the usual resistors, as 2% and 25, which may be shunted out of the circuit by means of speed relays 3 and 4.

A delayed-action relay 5 is illustrated as being connected across the terminals of the elevator-motor armature EM for a purpose which will be hereinafter described. This delayed-action relay is designed and constructed to operate its contact members 5a and 56 only when the voltage across the armature leads is such as to drive the motor EM at a speed greater than the landing speed, that is, greater than the speed at which the car moves just prior to its stopping at a landing. This relay will thus be effectively energized and deenergized only at such. times as the elevator attains this critical speed.

A series of push-buttons located at the floors are illustrated, the buttons F3U and F3D respectively representing the up and down buttons located at the third floor landing at some point adjacent the elevator shaft, and the buttons F2U' and F21) respectively representing the second floor up and down but-tons. Each button operates a push-button relay designated as B2B, 112T], R31) and R3U, respectively.

A series of push-buttons C3 and C2 are shown mounted upon the car C and are intended to be operated by the attendant upon the car in response to information given him by passengers on the elevator as to the floors at which they desire to leave the car.

No push-buttons have been illustrated for the upper and lower terminal floors, since the limit switches UL and DL, usually provided in elevator control systems, ill cause the car to stop at the upper and lower terminal floors, respectively, without the necessity of using passenger-operated push-buttons.

A series of signal inductor relays A311, A3D, A2U and A21) of the type disclosed in the copending. application of J. F. Clancy, Serial No. 559,997, filed May 11, 1922 and the application of H. V]. Williams, Serial No. 190,482, filed May 11, 1927, both of which are assigned to Westin house Electric and Mfg. Company, are illustrated as being located in the shaft for the elevator car A for magnetic cooperation with an inductor plate X carried by the car. Relays A3U and A8D are positioned adjacent the third floor landing at such distances from the floor level that the plate X will operate them prior to the entry of the car into the slow-down zone for that floor.

A set of landing inductor relays 30 and 31 are illustrated as mounted upon the car for magnetic cooperation with inductor plates 3YD, 2YD and 3YU and 2YU, respectively, which are located at the beginning of the slow-down zone for up and down travel for the second and third floors. The purpose of these relays is to initiate the slowing down and stopping of the elevator at such distances away from the floors that the car will normally come to a stop at a level with the adjacent floor. A set of levelling relays 87 and 88 are illustrated as mounted upon the elevator car A for cooperation with a series of inductor plates I and 1, respectively, (associated with each floor) to bring the car to a level with the floor in case it over-runs or under-runs the exact level and to maintain the elevator level with the floor while loading and unloading.

A series of signal inductor relays and control relays for a second elevator in the bank are designated by B3U, BSD, etc. and BT23 and BT2, etc., the letter B being substituted for the letter A in the reference character to indicate that these relays relate to a second elevator.

The system illustrated shows a two-car installation, each car operating between four floors, though it is obvious that any number of elevators may be used and the number of floorsmaybe changed. The description of the apparatus and circuits may best be understood with reference to an assumed operation.

Assuming the elevator to be standing at the first floor, or lower terminal, the attendant on the car C desiring to start an up trip, operates the push button U on the car C. The operation of button U closes a cirsuit for the up direction switch 1, which extends from line conductor L1 through conductor 10, normally closed contact members 2a, conductor 1.1, coil of up direction switch 1, conductor 12, the contact members of pushbutton U, conductors 13 and 14, contact members 5b, conductors 15 and 16, switch 17 on the elevator, and conductors 1.8 and 19 to line conductor L2.

Direction switch 1 closes a circuit for the generator shunt field winding which attends from line conductor L1 through conductors 10 and 20, contact members 10, conductors 21 and 22, generator shunt filed Winding GTF, conductor 23, resistors 24 and 25, conductors 26 and 27, contact members 1?), and conductors 28 and 29 and to line conductor L2. This circuit energizes generator field winding GP in the proper direction to cause tne generator to drive the motor EM to move the car upwardly.

As the car starts, the speed relay 3 is energized through a circuit which leads from line conductor L1 through conductors 6 and 32, the coil of relay 8, conductor 33, normally closed contact members of landing inductor relay 31, conductor 3 1, contact members of landing inductor relay 30, conductor 35, contact members 16, and conductors 28 and 29 to line conductor L2. Relay 3 closes its contact members 3?), shunting the resistor 2 1; and cansing the motor to speed up. The relay 8 also closes its contact members 3a, which completes a circuit for the second speed relay l, as will be hereinafter described.

When the resistor 24 is excluded from circuit, the voltage supplied to the armature of the motor EM will be such as to energize the relay 5 by way of circuit which extends from the motor armature conductor 9 through conductor 40, coil of relay 5, conductor l1, switch 412 on the elevator car and conductor 43 to the other armature conductor 8. Relay 5, in operating, closes its contact members 5a and opens its contact members 55. Contact members 5a close a holding circuit for the up direction switch 1 leading from line conductor L1, through conductor 10, contact members 2a, conductor 11, coil of relay 1 and conductor 12 to a junction-point 44, thence by way of conductor 45, contact members 1d, conductors 46 and 47, contact members 5a, conductor 16, switch 17 on the car and conductors 18 and 19 to line conductor L2. Relay 5 thus causes the direction switch 1 to continue the opera tion thereof until the speed of the motor is reduced to approximately the landing speed.

Relay 3, in closing its contact members 3a, completes a circuit for the operation of relay 4 by way of a circuit leading from line conductor L1 through conductors 6, 32 and 48, the coil of relay 4, conductor 49, contact members 3a, conductor 50, thence in series through the normally closed contact members of each of the inductor signal relays A3U, A31), A211 and A2D, by way of conductors 51, 52 and 53, thence through conductor 54, down limit switch DL, conductor 55, up limit switch UL, conductor 56, switch 57 on the car, and conductors 18 and 19 to line conductor L2. The operation of relay 4 shunts the resistor 25 from the generator shunt field circuit by way of contact members 46, thus causing the motor to accelerate to, and operate at, its highest speed.

Assuming that a person at the second floor desires to travel upwardly and operates the button F211, a circuit will be completed from line conductor L1 through conductors 60, 61 and 62, normally closed contact members A2Ua, conductor 63, contact members B2Ua (for car B), conductor 64, coil of the pushbutton relay R2U, conductor 65, push-button F211, and conductor 66 to line conductor L2. This circuit energizes the push-button relay R2U and this relay completes a self-holding circuit by shunting the button F211 by way of conductor 67, contact members R2Ua and conductor 68. Relay R2U also closes a cir cuit energizing the signal inductor relays A211 and B2U by way of a circuit which leads from line conductor L1 through conductors 10 and 70, contact members 1;, conductor 71, coil of signal inductor relay A2U, conductor 72, normally closed contact members AT2b (of a transfer relay hereinafter described), conductors 73 and 74, contact members R2117), and conductors 75 and 68 to line conductor L2. A parallel circuit leading through the signal inductor relay 1321] for elevator car B, taps the conductor 73 by a conductor 76 and traverses the corresponding contact members of the transfer relay BT2 for elevator B in a manner similar to that described for the operation of the first elevator.

As the car C, proceeding upwardly, approaches the second floor, the inductor plate X, carried by the car will be brought adj acentsignal inductor relay A2U, which relay, being energized actuates its contact members a and b to open-circuit position, causing the relay R2U to be restored to normal deenergized condition through contact members A2Ua, and initiating the slowing down and stopping of the elevator at the second floor, through contact members A2116 opening the circuit for the high-speed relay 4.

The contact members 4a of high-speed relay 4, in closing, energize the coils of the landing inductor relays 30 and 31 through a circuit which leads from line conductor L1 through conductors 80, 81, 82 and 83, the coilsof relays 30 and 31 to a common conductor 84, thence, through contact members 4a, conductors 85 and 47 contact members 5a, conductor 16, switch 17 and conductors 18 and 19, to line conductor L2. Relays 30 and 31 will be actuated when the elevator car arrives at the slow-down zone for the second floor by the relay 30 passing inductor plate 2YU cooperating with the inductor relay 30. Relay 30, in operating, opens the circuit for relay 3, as previously described, thus introducing further resistance into the generator field circuit and further slowing down the motor EM.

After the relay 3 has been deenergized and the car decelerates towards its landing speed (the normal speed when all of the generator shunt field circuit resistors are in circuit), the relay 5 will be deenergized, thus opening the holding circuit for up direction switch 1. The timing of the operation of switches 3, 5 and 1 will, under normal conditions, cause the car to stop accurately level with the floor, independent of the loading conditions of the car. If, however, the car should overrun or under-run the landing, the relays 87 and 88 would be actuated to start the car and bring it back to a level with the floor. The circuit for the coils of relays 87 and 88 leads from line conductor L1 through conductors and 81, coils of relays 87 and 88, and conductors 89 and 19 to line conductor L2.

Assuming the car to have over-run the landing, the relay 88 would be opposite the inductor plate 1 and the contact members of relay 88 would close, completing a shunt circuit around the down button I) on the car by way of conductors 91 and 94, contact members of relay 88, conductors 95 and 96 to the coil of down direction switch 2 and thence as described for up direction switch 1. The energization of down direction switch 2 would start the motor down until the inductor relay 88 moved from a position adjacent the inductor plate I. A like operation of relay 8'! would occur in case the elevator stopped short of the landing. This operation is disclosed in the application of J. F. Clancy, previously identified and forms no part of my invention.

J In order to prevent the elevator from stop only the down relays when the car is going down.

In the assumed case, the attendant next opens the second floor door, and the passenger gets on the car and tells the attendant at which floor he wishes to leave the car. The attendant then closes the door and operates the car button corresponding to the floor designated by the passenger. Assuming that the passenger desires to leave at the third floor, the attendant will operate the car button C3. This button closes a circuit for the transfer relay AT3 through a circuit which leads from line conductor L1 through conductors 60 and 01, door switch 97 at the third floor, conductor 98, coil of relay ATS, conductor 99, push-button C3 and conductors 18 and19 to line conductor L2. Transfer relay AT3, when energized, closes its contact mem bers and completes a self-holding c1rcu1t by .way of conductor 99, contact 111e1nber'AT30,

- signal. inductor relay A3111, conductors 103 and 104:, contact members ATiia and conductor 101 to line conduct-or L2.

The car will thus proceed upwardly to the third floor and will stop thereat in the manner described for the second floor stop,

To stop the car at the upper and lower terminals. the circuit for the relay 4 leads through the up limit switch UL and the down limit switch DL and the car will be stopped by the operation of this relay when it arrives at either terminal, as described for the second floor stop. The switches 17, 57 and 105, which are mounted on the car, are used to change the control connections for the car to eliminate at will, various features. The switch 12 may be opened, thus preventing the relay 5 from controlling the holding circuits for the direction switches, and the car will then operate as a straight car switch control elevator, it being necessary to hold the U or D button closed as long i as it is desired to have the elevator move. To

stop the car, the button will be released. The switch 17 acts as an emergency switch to open the control circuit for the push-buttons and .the direction switches andrender the entire a magnet 108 in such manner that energi Zat-ion of the magnet 108 will move the inductor iron X out of the path of the relays A3U, A211, etc. The circuit forthis magnet may be traced from line L1 through conductors 10 and 109, coil of magnet 108, conductor 110,

switch 105, and conductors 18 and 19 to line conductor L2.

It is seen that my system permits the attendant on the car to initiate the starting only. i

of the car and that thereafter the-elevator' may be stopped at any floor or floors in res ponse to the operation of push-buttons either at the floors or on the car, and the elevator will stop level with the landing at all such floors. By using the inductor landing relays, the car may be operated at highspeed to that point adjacent the floor at which it is to stop which is the shortest distance in which the elevator may bedecelerated to make a level stop with the floor. V

The showing of the apparatus is illustrative only and I do not desire to be limited to the use of the details of such apparatus, except as defined in the appended claims.

I claim as my invention:

1. In an elevator control system, a car, a variable-speed motor therefor, control means for controlling the speed and direction of said motor including a direction switch and.

a speed switch, means for initiating the operation of said direction switch, means con trolled by said direction switch for actuating said speed switch, means operable responsive to the speed of said motor for maintaining. said direction switch in operation while said motor is operating above a predetermined speed, and means dependent upon the position of said car for opening said speed switch to decrease the speed of said motor and there-.

by cause the speed responsive means to render said direction switch ineffective.

2. In an elevator control system, a car, a multi-speed motor therefor, means for controlling the direction and speed of said motorn to cause said motor to selectively operate at a predetermined landing speed and a running speed greater than said landing speed, means for operating said controlling means to start the motor, and means operable responsive to predetermined critical speeds of said motor above said landing speed for maintaining said control means operated independently of said operating means.

3. In an elevator control system, a car, a multi-speed motor therefor, means for controlling the direction and speed of said motor to cause said motor to selectively operate at a landing speed and a running speed, means for operating said controlling means, and means operable responsive to critical speeds of said motor above said landing speed for maintaining said control means operated independently of said operating means, and means including passenger operated call means operable to cause said motor to decelerate to a speed below said critical speed.

4. In a control system for an elevator car operable past a plurality of floors, motive means therefor to cause said car to operate Within a predetermined speed range and at higher speed, normally ineffective stopping means for said motive means, manually operable switch means to render said stopping means effective to cause said car to stop at any selected floor, and means comprising additional manually operable means to limit the speed of said car to said predetermined range and to render said stopping means effective to cause said motive means to stop said car at the floor next approached by said car.

5. In a control system for an elevator car operable past a plurality of floors, motive means to cause said car to travel within a predetermined speed range and at higher speed, normally ineifective stopping means for said motive means, means including passenger operated call buttons to render said stopping means effective to cause said motive means to stop said car at a selected floor, and means operable to limit the speed of said car to said predetermined range and to render said stopping means effective to cause said motive means to stop said car at the floor next approached.

In testimony whereof, I have hereunto subscribed my name this 8th day of June 1927.

RAY P. HIGBEE.

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