US2298174A - Elevator control system - Google Patents

Description

Oct. 6, 1942. sANT|N| I 2,298,174

ELEVATOR CONTROL SYSTEM Filed Sept. 4, 1941 2 Sheets-Sheet l A Iva Lrc 1 WITNESSES; INVENTOR I I 5; Darn/0 50/7/071.

/ ATTORNE Patented Oct. 6, 1942 ELEVATOR CONTROL SYSTEM Danilo Santim', Tenafly, N. J., assignor to Westinghouse Electric Elevator Company, Jersey City, N. J a corporation of Illinois Application September 4', 1941, Serial No. 409,491

11 (llaims.

My invention relates to elevator control systems and more particularly to such control systems as embody an arrangement of electromagnetic relays and inductor relays with their inductor plates for effecting deceleration, levelling and relevelling of the cars at the landing floors.

One object of the invention is to provide a simplified arrangement of apparatus which may be easily and quickly installed and which shall be inexpensive to construct, operate and maintain in operation.

Another object is to provide an arrangement of electromagnetic relays and inductor relays with their inductor plates and so connect them electrically that they will perform different functions under'different conditions of operation and thereby effect a saving in the amount of apparatus necessary for eiiicient operation.

Another object is to reduce the number of relays necessary in control systems of the abovementioned type for effecting efficient deceleration, levelling and relevelling of the cars.

Other objects will become apparent from the following description of the invention taken in conjunction with the accompanying drawings, in which:

Figure 1 is a diagrammatic representation, in what is known as the straight line style of an elevator control system embodying my invention;

Fig. 1A is an explanatory illustration of the relays embodied in the control system of Fig. 1. The illustration shows the relays with their coils and contact members disposed in horizontal alignment with their positions in the straight line circuits of Fig. 1 so that the identification of any relay and the position of its coil and contact members in the strai ht line circuits may be readily determined;

Fig. 2 is a diagrammatic representation of an inductor relay to be mounted on a car and a pair of inductor plates therefor mounted upon the walls of the hatchway in which the car operates; and

Fig. 3 is a reduced view in side elevation of the inductor relay shown in Fig. 2.

The relays embodied in the system are designated as follows:

U =up direction switch D :down direction switch UR=up direction relay DR=down direction relay M :car running relay N :auxiliary car running relay GR=high speed start relay 1P =low speed decelerating relay 2P :intermediate speed decelerating relay 3P =high speed decelerating relay L :decelerating and levelling inductor relay LU :up levelling relay LD :down levelling relay TA =time delay relay for one-floor runs. Holds direction switch just predetermined time to make one-floor run TB :anti-plugging relay TC :smooth-start relayprevcnts application of full speed at start.

Referring more particularly to the drawings, I have illustrated a car C as suspended by a suitable cable H which passes over a hoisting drum l2 to a suitable counterweight IS. A hoisting motor H is provided for operating the hoisting drum by means of a shaft to raise and lower the car.

A variable voltage system of control is provided for controlling the operation of the hoisting motor H wherein the motor armature HA is connected in a closed circuit 2! with the armature GA of a generator G. The generator is provided with a separately excited field winding GF which is connected for energization in a loop circuit 22 with the armature RA of a regulating generator B so that the output of the generator, and consequently the speed and direction of operation of the hoisting motor H may be controlled by controlling the operation of the regulating generator (hereafter called the regulator) An adjustable resistor rl is connected in the circuit of the generator field winding for adjusting the resistance of that circuit as desired. A commutator pole winding 24 for the generator G is connected in series in the loop circuit 2|.

The regulator R is provided with an armature RA, a self-exciting field winding RCF, a pattern field winding RPF, a diiferential field winding RDF, and a series field winding RSF.

The armatures of the generator G and the regulator R are mounted on a common shaft 2?] to be operated by a constant speed motor (not shown).

The self-exciting field winding RCF is connected in the loop circuit 22 inseries with the regulator armature RA and the generator field winding GF.

The pattern field winding RPF is connected across the supply conductors L+ and L so that the generator voltage and the direction of op eration may be controlled by controlling the direction and the value of the current in the pattern field.

A plurality of resistors T6 to TH) are connected in the circuit of the pattern field winding to so control the value of that winding that the generator G will be energized to cause the car to accelerate, run and decelerate at predetermined desired speeds.

The differential field winding RDF is connected across the terminals of the generator armature GA, An adjustable resistor 23 is inserted in series with the differential field winding RDF so that the value of that winding may be adjusted as desired.

The regulator series field RSF is connected in series in the loop circuit 2 between the armatures of the generator and the hoisting motor. This field winding is provided to cause the regulator to give the generator field winding suflicient excitation to compensate for the IR drop in the hoisting motor.

The regulator R and its connections are disclosed and claimed in Danilo Santini Patent No. 2,221,610, granted November 12, 1940, and assigned to Westinghouse Electric Elevator Company. Further details regarding the regulator and its functions may be secured in that patent.

An electromagnetic brake l9 having a coil ifla is associated with a shaft for stopping and holding the car when the power to the hoisting motor is cut ofi. A pair of resistors T4 and r5 is disposed in the circuit of the coil 19a to cause a soft brake action under certain conditions.

A car switch CS is mounted in th car for use by the car attendant to start and stop the car. The car may be started in the up direction by moving the car switch counterclockwise and in the down direction by moving it clockwise. When the car switch is centered, it causes the car to stop at the next floor.

The car switch controls the car by controlling the up direction relay UR and the down direction relay DR, which, in turn, control the up direction switch U and the down direction switch D.

The up direction switch U and the down direction switch D control the energization of the generator G by connecting the pattern field winding of the regulator to the supply conductors L+ and L for up direction or down direction operation of the car.

The car running relay M is controlled by the direction switches U and D and is provided for preparing certain circuits for operation when the car switch is thrown for movement of the car.

The auxiliary car running relay N is controlled by the relay M and is provided for controlling the brake coil l9a and for further preparing the control system for operation after operation of the car running relay M.

The high speed start relay GR is controlled by the direction switches U and D and. is provided for short circuiting the resistors in the pattern circuit of the regulator when the car is being started so as to secure desirable starting characteristics.

The smooth-start relay TC is a time delay relay controlled by the auxiliary car running relay for controlling the operation of the starting relay GR to secure smooth starting operation of the car, by preventing application of full speed until the car has gotten started at low speed.

I have provided an improved decelerating and levelling system for causing the car to decelerate to a stop level with the floor after the car switch is centered for a stop and also for causing it to relevel with the floor When it overruns. the floor level or drifts away from the floor level during a stop at the fioor landing.

In my improved system, I provide an inductor relay L to be mounted on the car C in position to cooperate with an upper magnetizable inductor plate E and a lower magnetizable inductor plate F at each landing floor.

The inductor plates E and F are illustrated as mounted on a hatchway wall I! adjacent to a fioor landing 18 by a plurality of angle braces 28. The plates should be disposed in vertical, overlapping position and horizontally apart a sufficient distance to permit the car to move the inductor relay L freely between them but close to them as it moves up and down in the hatchway.

In this particular system, it will be assumed that the inductor relay is approximately '7 inches long and that each of the inductor plates E and F is approximately 21 inches long and that the plates overlap about 7 inches. Hence, when the car moves the inductor relay to the centermost position between the plates, the top of the relay is approximately level with the upper end of the up plate F and the lower end of the relay is approximately level with the lower end of the down plate E. The inductor relay and the plates should, furthermore, be so positioned that the inductor relay L will be in 'its centermost position between the overlapping ends of the inductor plates E and F (as indicated by :r-.r in Fig. 2) for a fioor landing when the car floor is level with th fioor at that landing. The lengths of the plates and the relay may be varied as desired to adapt the system to meet various conditions in various installations, but it should be understood that the plates must be more than twice as long as the inductor relay. Also, the relay must be as short as or shorter than the length of the overlapping portions of the plates.

A first up armature iULA is mounted on the lower end of the inductor relay adjacent to the plate E. A second up armature ZULA is mounted on the upper end of the inductor relay 1 adjacent to the upper plate E. A first down armature iDLA is mounted on the upper end of the inductor relay adjacent to the lower plate F. A second down armature ZDLA is mounted on the lower end of the inductor relay adjacent the plate F.

The inductor relay is provided with an energizing coil 25 and a core 26. Each of the armatures is mounted on a biasing spring (not shown) which causes it to remain in a predetermined position until the inductor relay is moved adjacent to the plates with its coil energized, at which time the influence of the magnetizable inductor plate under the effect of the energized coil causes the armature to move from its normal position to a predetermined position. For instance, when the relay is above the plate E and approaches the plate in an energized condition, the armature IULA will be moved toward the plate as soon as it comes adjacent the upper end of the plate.

A first up pair of contacts lUL is disposed on the relay to be operated by the armature EULA. A second up pair of contacts 2UL is mounted On the relay in position to be operated by the armature ZULA. A first down pair of contacts IDL is mounted on the inductor relay in position to be operated by the armature IDLA. A second down pair of contacts ZDL is mounted on the inductor relay in position to be operated by the down armature ZDLA. The four pairs of contacts are normally closed and are moved to open position when the armatures associated with them are energized. These contacts are provided for controlling circuits used in decelerating and stopping the car.

With this construction, an up operation of the inductor relay to its center position with relation to the inductor plates at a landing floor when the car is coming to an up stop thereat will perate the armatures to open the contacts sequentially in the order lDL, 29L, ZUL and IUL. When the car is coming to a down stop at the floor, the movement of the relay down to its central position with reference to the plates E and F will cause the pairs of contacts to open sequentially in the order IUL, 2UL, EDL and IDL.

The car is provided with a high speed decelerating relay 3P, an intermediate speed decelerating relay 2P, and a low speed decelerating relay IP. The contacts and the circuits controlled by them are so arranged in th system (as will be described later in an assumed operation thereof) that they will operate or deenergize the decelerating relays in the order 3P, 2? and l? and the appropriate direction switch, regardless of the direction of the approach of the car to the floor when a stop is being made thereat. That is, the sequence of operation of the decelerating relays is always the same regardless of the direction of travel of the decelerating car and the appropriate direction switch for the direction of the stop is then operated.

Referring to Fig. 2, in a down decelerating and stepping action the line at! indicates the approximate distance of the car floor from the floor landing level at which the contacts IUL open to deenergize the relay $P to decelerate the car. The line 022 represents the approximate distance of the far floor from the landing floor level at which the contacts ZUL open to deenergiZe the relay 2?. The line m3 represents the approximate distance of the car floor from the floor landing level at which the contacts 2DL open to deenergize the relay P for decelerating the car to landing speed. The line an; represents the distance (approximately inch of the car floor) from the floor landing level at which the contacts IDL open to deenergize the relay LD to shut off the power and stop the car level with the landing floor.

In an up direction stop, the lines ml, m5 and 9:5 represent the points at which the contacts IDL, 23L, ZUL and [UL are opened sequentially to deenergize the decelerating relays in the same order, namely 3P, 2P, 2P and LU.

The lines 0315 and also represent the releveling points at which if the car stops short of, overruns, or drifts away from the floor level during a stop thereat, the first down contacts lDL or the first up contacts iUL will close to cause the direction switches to return the car level with the landing floor.

The inductor relay L is illustrated, described claimed in the patent application of Harold Williams et a1. filed July 25, 1940, Serial No. 347,650, to Westinghouse Electric Elevator Company, in which further details of the construction of the relay may be secured if desired. It is to be understood that any other suitable relay provided with four armatures may be used if desired.

The one-floor relay TA has a time delay of approximately 1.8 seconds when opening and it is designed to provide a holding circuit for the up direction relay UR or the down direction relay field winding HF, the inductor relay L, the time L when the hoisting motor at DR when the car switch is operated to its "on position and immediately returned to its center position to cause the car to make a one-floor run. This time delay relay holds the up or the down direction relay UR or DR energized for the correct amount of time to cause the car to make a one-floor run. Under this predetermined set up the car will accelerate to and run at its high speed for a one-floor run and then by deceleration at the proper time to a stop at the next floor.

The high speed relay 3P controls the amount of resistance r2 included in the circuit of the regulator series field winding RSF, the amount of resistance T3 in the regulator differential field winding RDF, and resistor TB in the circuit of the regulator pattern field winding RPF to cause the car to decelerate from high speed to intermediate speed.

ihe intermediate speed relay 2? controls the amount of resistance r53 in the regulator pattern field winding RPF to decelerate the car from inten iediate speed to low speed and also conditions the circuits for relays U and D, M and N for certain operations.

The low speed decelerating relay lP controls the use of resistance H8 in the regulator pattern field winding circuit RPF to decelerate the car from low speed to landing speed and the use of resistances rd and T5 in the circuit of the brake coil to soft-en the brake for prompt braking action when the stop is made.

The up leveling relay LU (controlled by the contacts IUL) operates the up direction switch U to stop the car as it comes into the floor at landing speed in the up direction and also to relevel it upwardly if it overruns the floor in making a down stop or drifts below the floor level during a stop at the floor.

The down leveling relay LD (controlled by the contacts lDL (deenergizes the down direction D to cut off the power and stop the car as it comes into the floor at landing speed in the down direction. This relay also operates the switch D to relevel the car downwardly if it overruns the floor in making an up stop or drifts above the floor during a stop thereat.

The anti-plugging relay TB is provided with a time delay of approximately .3 second and operates to prevent energization of the inductor relay car is traveling at full speed and for a fraction of a second after retardation starts so that the releveling switches cannot plug the too high a speed.

The relay SP is also provided with contacts 3P4 in the circuit of the up direction relay UR. and DR which permits the release of the onefioor run holding circuit provided by the relay TA when the car is closer to a floor than its normal one-floor run distance when it is started toward that floor.

It is believed that the invention will be best understood by the following assumed operation of the system illustrated in the drawings. It should be noted, however, that the particular dimensions, periods of delay, amounts of resistinvolved, etc., are given as an illustration of what may be included in an operating system but that other values may be readily used in adapting the system to meet the various conditions under which it be necessary to install the elevators.

It will be assumed that the switches l5 and I6 are closed to prepare the control circuit for operation. This action energizes the hoisting motor delay relay TA and the smooth start relay TC. It will be assumed that the car is starting at the eighth floor landing level with the floor. Therefore, the inductor contacts IUL, 2UL, lDL and ZDL are all open because of the energized condition of the inductor relay L and its position between the inductor plates E and F for that floor.

It will be assumed now that the car attendant operates the car switch CS in clockwise direction to start the car down to the second floor. The operation of the car switch for the down direction closes its contact 33 thereby energizing the down direction relay DB by the circuit L+, UB3, DR, 33, CS, L

The energized down direction relay DB opens its contacts DBI and DB3 and closes its contacts DB2, DB4 and DB5. The closing of the contacts DB2 prepares the circuit of the down direction switch D for operation. The closing of the contacts DB4 prepares the starting relay G for operation. The closing of the contacts DB5 energizes the anti-plugging relay TB.

The energized anti-plugging relay TB opens its back contacts T133 thus deenergizing the inductor relay L which causes the decelerating and leveling contacts IUL, ZUL, IDL, ZDL on the inductor relay to reclose, thus energizing the decelerating relays i? and 2P and the leveling relays LU and LD which will remain in that condition until the car is decelerated and stopped.

It will be assumed now that the door safety contacts 40 and 4! are closed by the closing operation of the car gate and floor door (not shown) and that this completes the circuit for energizing the down direction switch D which follows:

The energized down direction switch D closes its contacts Di, D2, D4, D5, D6 and D9 and opens its back contacts D3, D1 and D8. The closing of contacts D5 prepares a self-holding circuit for the down direction switch D. The closing of the contacts Dd energizes the car running relay M by the circuit L+, M, D4, DB2, 59, 4|, UB2, L

The closing of the contacts DI and D2 prepares the pattern field winding RPF of the regulator B for operation in the down direction.

The closing of the contacts D9 energizes the decelerating relay 3P by the circuit.

The energized relay 3P opens its contacts 3P! to insert the resistor T2 in series with the regulator field winding BSF; opens its contacts 3P2 around the resistor r3 in series with the regulator differential field BDF; and closes its contacts SP3 to short circuit the resistor 18 in the circuit of the regulator pattern field winding BPF. These actions prepare the system for certain desired operations to be described later during the deceleration and stopping of the car.

Returning now to the energized car running relay M, which opened its back contacts MI and closed its front contacts M2, M3 and M l, the openin of the contacts Ml inserts the resistor 73 in series with the regulator differential field winding BDF. The closing of the contacts M2 prepares the brake coil lfia for operation. The closing of the contacts M3 completes the circuit through the pattern field winding RPF for the down direction as follows:

Inasmuch as the regulator armature BA is being operated at a constant speed, the energization of the pattern field winding BPF prepares the regulator to start the delivery of energy of a predetermined value to the generator field winding GF.

The closing of the contacts M5 energizes the auxiliary running relay N by the circuit L+, N, M 1, D4, DB2, E9, 4 I UB2, L

The energized relay N closes its front contacts N! and N2 and opens its back contacts N3 and N4. The closing of the contacts NI connects the generator field winding GA for energiz'aticn in the loop circuit 22 with the armature BA of the regulator. Inasmuch as the generator armature is being rotated at constant speed, the energization of the generator field winding causes the generator to deliver energy to the hoisting motor. At the same time, the relay N closes its contacts N2 thereby energizing the brake coil lfia by the circuit L+, N2, BK, Na, M2, 2-

The energization of the coil Ilia releases the brake I9 and the car starts to move downwardly.

The opening of the contacts Ni deenergizes the smooth start relay TC and after the expiration of .3 second that relay opens its contacts TC! which had included the resistors T6 and T1 in the circuit of the pattern field for starting purposes in order to secure a smooth start. The deenergization of the relay TC also closes its back contacts T02 which completes the energization of the starting relay GB by the circuit The energized relay GB closes its contacts GB! thereby short circuitin the resistors r1, T8, 19 and rlfi in the pattern field winding BPF. This increases the energization of the pattern field circuit which causes the generator G to increase the speed of the hoisting motor H to its high running speed.

The car is moving downwardly now and at the end of approximately 1.8 seconds after the car starts, the one-floor run relay TA, which was deenergized by the opening of the contacts N3 when relay N was energized, drops out and opens its contacts TA! but this has no efiect on the operation of the car because the car switch remains closed on its contact 33 which keeps the down direction relay DB energized.

When the car arrives at a position where it is from one-half to one floor above the second floor at which it is to be stopped, the attendant centers the car switch CS to cause the car to stop at the second floor. The centering of the car switch CS removes it from the contact 33, thus deenergizing the down direction relay DB which closes its back contacts DB! and DB3 and opens its front contacts DB2, DBQ, and DB5.

The opening of the contacts DB4 deenergizes the starting relay GB which thereupon opens its front contacts GB! to remove its short circuit around the resistors r1, r8, T9 and T10. However, it will be observed that, inasmuch as the decelerating relays IP, 2P and 3? are in energized condition, the resistors r8, T9 and THE still remain short circuited by the decelerating relay contacts, and that as the car approaches the next stop, these resistors will be reinserted in the pattern field winding circuit one by one as the car approaches the floor at which the stop is to be made.

It should be noted that the resistors 1'6 and 1! remain in series in the circuit to the field BPF after the opening of the contacts GR! and thereby reduce the supply of energy to the pattern field circuit, thus causing deceleration of the car from its high running speed to its high decelerating speed as it approaches the inductor plate zone for the second floor which starts approximately 21 inches above that floor.

The opening of the contacts DB deenergizes the anti-plugging relay TB which, after the expiration of a .3 second delay, closes its back contact T133 thereby energizing the inductor relay L so that when it is brought opposite to and moved along the inductor plates and F, its contacts will be operated sequentially to decelerate the car to the down stop at the second floor.

As the car moves down to within approximately 21 inches of the second floor landing, it carries the energized inductor relay L down to the inductor plate E, and, as the contacts IUL come exactly opposite the upper end of that plate, they are operated by the flux induced in the plate through the energized relay, to move to their open position, thus deenergizing the leveling relay LU to open its front contacts LUI and LU3 and close its back contacts LUZ. The opening of the contacts LU3 deenergizes the high speed decelerating relay 33? which thereupon opens its contacts 3P3 thus inserting the resistor T8 in the circuit for the pattern field winding to decelerate the car from its high decelerating speed to its intermediate decelerating speed.

At the same time, the deenergized relay 3P recloses its contacts 31 2, thus short circuiting a portion of the resistor r3 in series with the differential field winding RDF and thereby strengthening that regulator field winding for the purpose of renderin the deceleration more effective.

Also at the same time, the deenergized relay 3P recloses its back contacts 3PI and short circuits some of the resistor T2 in circuit with the series field winding RSF to strengthen that series field winding to keep th regulation flat.

As the car decelerates from its high decelerating speed to its intermediate decelerating speed, it approaches to within approximately 14 inches of the down stop at the second floor and thereby moves the energized inductor relay L down to the point that its contacts ZUI come opposite the upper edge of the plate E and are operated to open position by the induced flux passing through the plate and the armature attached to the contacts. The opening of the contacts 2U! deenergizes the decelerating relay 2P which thereupon opens its contacts 'ZPI, 2P2, and 2P3. The opening of the contacts ZPI re-inserts the resistor T9 in the circuit of the pattern field of the regulator thus causing the regulator to decrease the amount of power supplied to the generator and thereby decreases the speed of the hoisting motor H and the car C from intermediate speed to low speed.

As the car drops still lower and arrives at a point about 7 inches from the second floor, it moves the energized inductor relay L downwardly to a point Where its contacts ZDL come opposite the top of the inductor plate F and are thereby operated to their open position, thus deenergiz ing the decelerating relay IP which, in turn, opens its contacts lPl and thereby reinserts the resistor HQ in the circuit of the pattern field which reduces the speed of the hoisting motor from low speed to what is known as a landing speed (approximately 15 feet per minute).

The deenergized relay i? also opens its contacts IP2 and 1P3 in the circuit of the brake coil lea thereby reinserting the resistors rd and r5 in the brake circuit to weaken the brake coil for a quick dropout. It will be noted that the contacts BK operated by a mechanical switch (not shown) on the brake still remain open because the brake is still in released condition, thereby rendering effective the operation of the contacts IP2 and IP3.

As the car approaches the stop closely and its floor comes within, say, one-half inch of the floor level of the landing, it moves the energized inductor relay L down until its contacts IDL come opposite the upper end of the plate F and are thereby operated to their open position, thus deenergizing the down direction leveling relay LD which opens its front contacts LUI and LUB and closes its back contacts LUZ to stop the car. The opening of the contacts LD2 deenergizes the down direction relay D which thereupon opens its contacts DI and D2 thus deenergizing the regulator pattern field circuit and causing the hoisting motor to stop. The opening of the contacts LD2 also deenergizes the car running relay M and the auxiliary car relay N. Thereupon the deenergized relay N opens its contacts N2 thus applying the brake I 9 to prevent further operation of the hoisting motor and the car.

The car is now stopped level with the floor because the operation of the inductor relay contacts IDL as the car arrived within one-half inch of the floor, caused the shutting off of the power and the application of the brake to stop the car at the instant it leveled with the floor landmg.

The deenergized relay N also recloses its back contacts N3 and N4 thereby reenergizing the one-floor run relay TA and the smooth start relay TC so that they will be ready for use when next needed in the operation of the car.

It should also be noted that the deenergization of the car running relay M closes its back contacts Ml thereby eliminating an additional portion of the resistor r3 from the circuit of the differential field winding RDF which gives that field full killing strength for any residual magnetism in the armature HA of the hoisting motor. Also, the deenergized relay N opens its contact members NI in the circuit of the generator field winding GF to stop the flow of energy through that field winding.

The car has now completed its run down to and stopped at the second floor.

Assume now that the car overran its stop or that it drops, due to cable stretch in loading while it is standing at the second fioor, say, more than one-half inch below the floor level. This causes the car to be releveled upwardly because, when the car moves the energized inductor relay down so that its contacts IUL drop below the lower end of the inductor plate E, they reclose and thus energize the leveling relay LU by the circuit L+, IUL, LU, L-

The energizing leveling relay LU immediately closes its contacts LUI, thus energizing the up direction switch U to close its contacts Ui and U2 in the circuit of the pattern field winding RPF, thus preparing it for up operation of the car. The energized switch U also closes its contacts U3 and U4 thus energizing the car running relay M which, in turn, closes its contacts M4 thus reenergizing the auxiliary car running relay N.

The energized relay M also closes its contacts M3 thus completing the energization of the pattern field winding RPF of the regulator to cause the starting of the hoisting motor for moving the car in the up direction. The energized relay N closes its contacts N2 thus completing the circuit through the brake coil lea and causing the brake 9 to be released so that the car may be returned to its position level with the second fioor landing. The energized relay N also opens its contacts N3 and N 1 in the circuit of the onefloor run relay TA and the smooth start relay TC thus preparing them for eventual operation after their time delay expires.

As the car moves upward in returning to its position level with the second floor landing, the inductor relay L returns to the position where its contacts IUL come opposite the lower end of the plate E and are again opened to deenergize the leveling relay LU which, in turn, opens its contacts LUI thus deenergizing the up direction switch U, the car running relay M and the auxiliary car running relay N to stop the car. The deenergized relay M opens its contacts M3 thus deenergizing the pattern field winding RPF and the deenergized relay N opens its contacts N2 thus deenergizing the brake coil Ida and returning the brake to its applied position to hold the car level with the second floor.

The deenergized relay N also recloses its back contacts N3 and N4 to reenergize the one-floor run relay TB and the smooth start relay TC ready for the next operation of the car.

The foregoing action illustrates how the releveling operation takes place when the car, for any reason, moves below the fioor level of the landing at which it is stopped. If the car should drift away from the floor in the up direction for any reason, the contacts iDL on the inductor relay L would be moved above the upper end of the inductor plate F and thereby cause energization of the down direction leveling relay LD to return the car to its floor level.

The system is particularly suited to an elevator with a car having a high running speed of approximately 350 feet per minute, and in which the retention of the resistors T6 and r! in the pattern circuit by the opening of contacts GRI will reduce the high-running speed of the car to a high decelerating speed of approximately 200 feet per minute as it moves the inductor relay toward the inductor plate zone for the next stop. Then as the car enters the inductor plate zone, the high speed decelerating relay 3P, the intermediate speed relay 2?, and the low speed relay 1? are deenergized in quick succession. This rapid weakening of the regulator pattern field combined with the strengthening of the differential field produces a rapid retardation which tests show will stop any car load, except the heaviest loads, level with the floor without overrun or underrun in any zone of approach at a regulated constant speed. The novel features of control embodied in this specification but not claimed herein may be found described and claimed in greater detail in the copending application of William F. Eames, Serial No. 407,414, filed August 19, 1941, and assigned to Westinghouse Elevator Company.

The assumed operation of the system'illustrates how my improved system of a plurality of decelerating and stopping relays and one inductor relay with only two inductor plates may be arranged and used to provide a large number of decelerating points, and leveling and releveling actions in a simple and inexpensive manner and one requiring a small amount of apparatus for the results obtained.

The assumed operation also illustrates an elevator control system in which I have obtained an unusual plurality of operations of a plurality of electromagnetic relays by the use of one inductor relay and two inductor plates and furthermore how I have provided for operation of the electromagnetic relays in a predetermined order regardless of the direction of operation of the elevator car.

Although I have illustrated and described only one specific embodiment of my invention, it is to be understood that modifications thereof and changes therein may be made without departing from the spirit and scope of the invention.

I claim as my invention:

1. An elevator control system comprising a car serving a landing floor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted in the hatchway in vertical and spaced apart relation adjacent to the landing fioor with one plate overlapping the other by approximately one-third its length, an inductor relay having a core member and an energizing coil disposed thereon mounted on the car in position to pass between the plates when the car rises or descends said inductor relay having a length of approximately one-third the length of either plate, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized, a pair of contacts associated with each armature to be operated thereby, a high relay, an intermediate relay, a low relay, an up direction switch, a down direction switch, circuits responsive to operation of the contacts by the armatures for causing operation of the relays and switches in the order high relay. intermediate relay, low relay, and down direction switch when the car makes a down stop and in the order, high relay, intermediate relay, low relay and up direction switch when the car makes an up stop at the landing fioor, and for operating the up direction switch if the car moves below the landing floor and for operating the down direction switch if the car moves above the landing fioor during a stop thereat.

2. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted in the hatchway in vertical and spaced apart relation adjacent to the landing fioor with one plate overlapping the other by approximately one-third its length, an inductor relay having a core member and an energizing coil disposed thereon mounted on the car in posilower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when. the car approaches a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized, a pair of contacts associated with each armature to be operated thereby, a high relay, an intermediate relay, a low relay, an up direction switch, a down direction switch, and circuits responsive to operation of the contacts by th armatures for causing operation of the high, intermediate and low relays and the switches in the order high relay, intermediate relay, low relay, and down direction switch when the car makes a down stop and in the order, high relay, intermediate relay, low relay and up direction switch when the car makes up stop at the landing fioor.

3. An elevator control system comprising a car serving a landing fioor a hatchway, an upper magnetlzable plate and a lower magnetizable plate mounted in the hatchway in a vertical and spaced apart relation adjacent to the landing floor with one plate overlapping the other by approximatel one-third its length, an inductor relay having a core member an energizing coil disposed thereon mounted on the car in position to pass between th plates when the car rises or descends, said inductor relay having a length of approximately one-third the length of either plate, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of th relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when th car approaches a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized, a high relay, an intermediate relay, a low relay, an up direction switch, a down direction switch, and circuits connecting the 'high, intermediate and low relays and the switches and controlled by th armatures to cause operation of the relays and switches in the order high relay, intermediate relay, low relay, and down direction switch when the car makes a down stop at the landing floor and in the order, high relay, intermediate relay, low relay and up direction switch when the car makes an up stop at the landing floor.

4. An elevator control system comprising a car serving a landing fioor in a hatch-way, an upper magnetizable plate and a lower magnetizable plate mounted in the hatchway in vertical and spaced apart relation adjacent to the landing floor with one plate overlapping the other by approximately one-third its length, an inductor relay provided with an energizing coil and mounted on the car in position to pass between the plates when the car rises or descends, said inductor relay having a length of approximately one-third the length of either plate, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay On its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop at the landing floor with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop at the landing floor with the inductor relay energized, a high relay, an intermediate relay, a low relay, an up direction switch, a down direction switch, and circuits responsive to operation of the armatures for operating the high, the intermediate and the low relays in the same sequence regardless of the direction of stopping of the car and for then causing operation of the direction switch corresponding to the direction in which the car approaches the stop.

5. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted on the inner wall of the hatchway in vertical, overlapping, and spaced apart relation adjacent to the landing floor, an inductor relay having an energizing coil and mounted on the car in position to pass between the plates when the car is moved past the landing floor, said inductor relay being as short as or shorter than the overlapping portions of the plates and the plates being more than twice as long as the inductor relay, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on th upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby the armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approache a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized, a high relay, an intermediate relay, a low relay, an up direction switch, a down direction switch, and circuits connecting the high, intermediat and low relays and the switches and controlled by the armatures to cause operation of the relays and switches in th order high relay, intermediate relay, low relay, and down direction switch when the car makes a down stop at the floor and in the order, high relay, intermediate relay, low relay and up direction switch when the car makes an up stop at the floor.

6. An elevator control system comprising a car serving a landing floor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted on the inner wall of the hatchway in vertical, overlapping, and spaced apart relation adjacent to the landing floor, an inductor relay having an energizing coil and mounted on the car in position to pass between the plates when the car is moved past the landing floor, said inductor relay being as short as or shorter than the overlapping portions of the plates and the plates being more than twice as long as the inductor relay, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby the armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized, a plurality of speed decelerating relays, and circuits responsive to operation of th armatures for always operating the speed decelerating relays in the same sequential order when the car approaches a stop at the fioor regardless of its direction of travel.

'7. An elevator control system comprising an elevator car serving a landing floor in a hatchway, two magnetizable inductor plates mounted in vertical, spaced apart and overlapping position on the inner walls of the hatchway adjacent to the landing fioor, an inductor relay mounted on the car in position to pass between the plates when the car is moved up or down in the hatchway, a coil for energizing the relay, four armatures mounted on the inductor relay in position to be operated successively in one sequence by the induction of said plates when the car approaches an up stop at the landing floor with the inductor relay energized and to be operated in another sequence by the induction of said plates when the car approaches a down stop at the landing floor with the relay energized, a plurality of speed decelerating relays, and circuits responsive to operation of the armatures for always operating the speed decelerating relays in the same sequence regardless of the direction of travel of the car when it approaches a stop at the floor.

8. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted in the hatchway in vertical and spaced apart relation adjacent to the landing floor with one plate overlapping the other, an inductor relay having an energizing coil mounted on the car in position to pass between the plates when the car rises or descends, said inductor relay having a length less than that of the overlapping section of the plates and each plate being more than twice as long as the relay, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop at the floor with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop at the floor with the inductor relay energized, a plurality of speed decelerating relays, an up direction switch, a down directionv switch, and circuits responsive to operation of the armatures in either order for always operating the speed decelerating relays in the same sequential order and the appropriate direction switch when the car approaches a stop at the fioor regardless of its direction of travel.

9. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted on the inner wall of the hatchway in vertical, overlapping, and spaced apart relation adjacent to the landing floor, an inductor relay provided with an energizing coil mounted on the car in position to pass between the plates when the car is moved to the landing fioor, said relay being shorter than the over lapping portions of the plates and the plates being more than twice as long as the relay, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop at the fioor with the relay coil energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop at the fioor with the relay coil energized.

10. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted on the inner wall of the hatchway in vertical and spaced apart relation adjacent to the landing floor with one plate overlapping the other by approximately onethird its length, an inductor relay having an energizing coil disposed thereon mounted on the car in position to pass between the plates when the car rises or descends, said inductor relay having a length of approximately one-third the length of either plate, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, and a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop with the inductor relay energized, and in the order first down armature, second down armature, second up armature and first up armature when the car approaches an up stop with the inductor relay energized.

11. An elevator control system comprising a car serving a landing fioor in a hatchway, an upper magnetizable plate and a lower magnetizable plate mounted in the hatchway in vertical and spaced apart relation adjacent to the land ing floor with one plate'overlapping the other, an inductor relay having an energizing coil mounted on the car in position to pass between the plates when the car rises or descends, said inductor relay having a length of less than the overlapping section of the plates and each plate being three times or more as long as the relay, a first up armature mounted on the lower end of the relay at its upper plate side, a second up armature mounted on the upper end of the relay at its upper plate side, a first down armature mounted on the upper end of the relay at its lower plate side, and a second down armature mounted on the lower end of the relay on its lower plate side, whereby said armatures will be operated in the order first up armature, second up armature, second down armature and first down armature when the car approaches a down stop at the floor with the inductor relay energized, and in the order first down armature, second down armature, second up armature and. first up armature when the car approaches an up stop at the floor with the inductor relay energized.

DANILO SANTINI.

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