US2250272A - Elevator control system - Google Patents

Description

y 2, 1941. M. A. MYERS 2,250,27

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 6 Sheets-Sheet 1 ATTO RN EYS July 22, 1941.

M. A. MYERS ELEVATOR CONTROL SYSTEM- Filed Nov. 15, 1959 e Sheets-Sheet 2 GCR GCL TR l/7/ ercepf/bn Se/ecfor [6 II! /6 L /5 III IN V E N TO R fiforf/merA/vyers ATTO R N EYS July 22, 1941. A, MYERS 2,250,272

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 6 Sheets-Sheet 4 Magnef 55 INVENTOR Mort/7220A Nye/s BY %WF ATTORNEYS July '22, 1941. M. A. MYERS 2,250,272

ELEVATOR CONTROL SYSTEM Filed Nov. 15, 1939 v 6 Sheets-Sheet 5 M-s Q/Z;

ATTORNEYS rection toward the first floor.

Patented July 22, 1941 UNITED STATES PATENT OFFICE ELEVATGE CONTROL SYSTEM Application November 15, 1939, Serial No. 304,572

19 Claims.

This invention relates to an elevator control system more particularly for use in buildings having more than two floors and in which no attendant is necessary in the elevator to control its operation, its operation being entirely under.,, the control of the persons using it. The elevator control system of the invention is especially adapted for use in buildings of medium height which are frequented by a considerable number of people such as, for example, apartment houses,,l of from to is stories.

Elevator control systems have been proposed in which push buttons are provided on the various floors and complicated mechanical apparatus is disposed in the elevator shaft for causing the l starting of the elevator in response to the operation of a fioor push button and for causing its stopping at a desired floor. It is a purpose of the present invention to avoid the use of complicated mechanical apparatus in the elevatorshaft and to control the elevator largely by electrical means in the form of electrical circuits which comprise relays, switches and associated apparatus most of which may be positioned in the same control room with the hoisting drum 5 and the electric motor which drives it.

It is accordingly an object of the present invention to provide an elevator control system in which the elevator will automatically start from one floor and automatically stop at another floor in response to the pressing of a hall button at the latter floor. Should the car he at the fifth floor, for example, and a hall button be pressed at the first floor, the car will automatically start and proceed to the first floor where it will automatically stop. According to a further feature of the invention, a super interceptive system is provided which stops the car automatically at the third floor, for example, in response to the pressing of a third fioor hall button while the car is moving down between the fifth and third floors. The call for the first floor is not cancelled, however, and the car is automatically started after the passenger on the third floor has entered and proceeds in its established di- It is a further object of the invention that calls are automatically cancelled after they have been answered, so that in the example given, the car will not again return to the third floor after it has completed its trip in the established direction by stopping at the first floor.

According to another object of the invention the super interception system includes a selector device which is mechanically associated with the elevator and is effective in preventing the car from answering a call in a direction opposite to the established direction of car travel. For instance, in the above illustrated example, the car will not respond to the pressing of a hall button, on the seventh floor after the car has started in its established direction toward the first floor. This results in giving control of the car to the person who initiates the first call. In the illustrated example, the partly desiring the car on the seventh floor would have to press the seventh floor hall button after the car had made its stop at the first floor.

Other objects of the invention wil become apparent to those skilled in the art as the description thereof proceeds. For a better understanding of the invention, however, reference is made to the accompanying drawings in which,

Figs. 1, 2, 3 and 4 represent diagrammatically an elevator control system embodying my invention and,

Figs. 5 and 6 represent diagrammatically an alternative modification of that portion of the system shown in Figs. 1 and 2.

Referring first to Figs. 1 to l, the control system embodying the invention is shown associated with an elevator car i which drives a stopping selector shaft 2 by means of a flexible drive member illustrated as a chain 3 which passes around a sprocket wheel 4 secured to the shaft 2. The shaft 2 thus rotates in timed relation with the elevator car i and carries a series of stopping selector cams 5, 5", 5" and 5" for controlling the stopping of the car at the first, second, third and fourth floors respectively of the building. These cams operate the levers 6 through the friction rollers l, the levers 6 serving to open and close a circuit through the upper pairs of contacts 8, 8", 8" and 8 and the rollers 7 serving also to operate the movable switch blades 9, 9", 9" and 9"" which cooperate with the fixed contacts I0, it", ill and 2" respectively. The shaft 2 drives a second selector shaft H by means of the sprockets I2 and I3 which are connected by a sprocket chain l4. Shaft II carries a series of interception selector cams l5, i5, 15, |5"" which operate the movable switch blades l 6, I6", l6 and l6 which cooperate with the pairs of left and right switch contacts, ll, "3, ll", [8", ll, iii and Il"", l8 respectively. Shaft H also carries a series of direction selector cams l9, [9", IS' and la which operate the movable switch blades 20, 23", 29 and 251" which cooperate with the pairs of left and right switch contacts 2|, 22; 2!, 22"; 2F, 22" and Zl",

22 respectively. The elevator motor 23 equipped with a brake magnet 24 of the usual type is provided with the usual type of driving connection (not shown) to the elevator l and is adapted to be supplied with power from the three pha-e power lines Li, L2, L3 through the circuits hereafter described. Hail push buttons 25, 25',

w and at the first, second, third and fourth doors respectively of the building are shown a s 'lar series of push buttons 25", and 2 are provided in the car I.

The remaining elements of the system may be best described in connection with the operation or" the car which is shown stopped at the third floor in Pig. 3. Upon a person on the first floor wishing to use the car, he pushes the first floor hall button which establishes circuit #1 extending iroin through lead 23, movable contact 29 of a stopping relay SR, lead 30 which is common to the car push buttons 26, 26" etc., hall push button cut-out switch 3i, hall push buttons 25, etc., lead 32, contact l8, switch blade [6, lead 33, first floor relay FRi, resistor Bi and lead 2? to Li. The completion of this circuit causes the relay PM to be energized and to close, thereby establishing circuit #2. The stopping relay SR and a similar relay SR! are each provided with a dash pot device 34, 34 to cause a suitable time clay in the return of the relay arinatures after the interruption of the current through their windings.

Circuit #2 connects L2 to Li through lead 28, movable relay contact 29, lead 35, lower contact 36 of relay FRi, coil of relay FRI, and RI. The closure of this circuit causes current to be bypassed around the interception selector contact i8 and hall push button 25 and the floor relay FRI sustains without continuing the pressure on the push button 25. The completion of circuit #2 and operation of floor relay FRI establishes circuit #3 which connects L2 to Ll through lead 28, auxiliary contact 31 of the up relay UR, coil of down relay DR, down contact 2| of direction selector switch 20, and upper contact 38 of floor relay FRI. The result of the completion of this circuit is that the down directional relay DR closes and sustains thereby establishing circuit #4. Circuit #4 connects L2 to Ll through lead 28, emergency stop button SB which is located in an accessible place in the car I, hatchway door contacts 40, 40", 43" and 49", contact 41 of stopping relay SR1, lead 42, top contact 43 of down relay DR, lead 44, coil of gate pilot relay GP, lead 25, and movable contact 46 of a time relay TR which is provided with a dash pot device 47 of any suitable type and an energizing winding 48. The result of the passage of current through circuit is the closure and sustaining of the gate pilot relay GP and the establishing of circuit #5.

Circuit comprises L2, lead 28, top contact 49 of gate pilot relay GP, the coil of car gate closing relay GCRfthe car gate closing limit switch GCL, lead 27 and LI. Passage of current through this circuit causes the gate closing relay to operate, thereby establishing a circuit (not shown) for the car gate motor which closes the gate of the car. The closure of the car gate automatically closes the switch contact 50 which is mechanically associated with the gate and also raises a door lock retiring cam 5| carried on the car which in turn closes the switch contact 52" and establishes the door lock circuit. This causes the establishing of circuit #6 which comprises L2, lead 28, stop button SB, hatchway door contacts' 43 to 45, relay contact 4|, car gate switch contact 50, lead 53, down stopping limit switch DS, auxiliary switch contact 54 of the up switch U, the coil of down switch D, lead 55, contact 43" of relay DR, lead 56, hatchway door contacts 52 to lead 5'1, lower gate pilot contact 49", lead 21 and LI. The passage of current through the coil of down switch D causes this switch to pull in and establish circuit #7.

Circuit #1 comprises L2, lead 28, stop button SB, hatchway door contacts 46 to 46", relay contact 4i, car gate contact 55, lead 39, main potential switch coil P, lead 58, lower auxiliary contact 59 of down switch D, lead 55, third contact 43 of direction relay DR, lead 56, door lock switches 52 to 52, lead 51, third contact 49 of GP, lead 27 and LI. The result of the closure or" this circuit is ie operation of main potential switch P, and the connection of the terminals T3, T2 of motor 23 to the mains L2 and L3 through the circuit comprising lead 28, lower contact 60 of switch P, lead 6i, lower main contact 62 of down switch D, lead 63, lead 84, upper switch contact 62, and lead 55. Motor terminal Tl is simultaneously connected to supply main Ll through the circuit shown including the lead 21 and switch contact 65. The current through the motor causes it to rotate so as to move the car in the down direction, as desired. It will be noted that the closing of down switch D caused the circuit including lead 66 and the coil of the up motion switch U to be broken at the upper witch contact 59', thus preventing the operation of the switch U which controls the motion of the car in an upward direction and thereby providing an electric interlock. It will also be noted that the circuit through the UR coil is broken at the contact 3'! of DR and thus prevents the car from responding to a call in the opposite direction to its established direction of travel as determined by the first call.

The next circuit established is #8, the stopping circuit. It will be noted that all the interception selector contacts [8, l8" and l8 are shown to the right the only one being shown to the left being that one, IT, for the third floor at which the car is located. This means that the cams 5 to l5" are so arranged that the only time an interception selector switch blade, 16 to 16, is thrown to the left is when the car is located at a particular floor either idle or moving. Thus when the car arrives at its destination, in this case the first floor, cam l5 throws switch blade Hi to the left into engagement with contact l1 thereby establishing circuit #8 which comprises L2, lead 28, stopping relay contact 29, lead 35, floor relay contact 36, lead 33, switch blade l6, contact l1, first floor stopping selector switch contacts 8, lead 58, coil of stopping relay SRl, lead 21 and Li. This circuit is not broken by movement of SR contact 29 but the closure of this circuit causes the armature and contact 4| of relay SRI to pull in and compress a spring in the dashpot device 34. When the car arrives in position for cam 5 to engage roller 1 and operate switch lever 6 to break the circuit at switch contacts 8, the coil of relay SR! is deenergized and contact 4| opens momentarily. We have seen that contact 41 is included in circuit #4, the gate pilot coil circuit, also in circuit #6 which includes the coil of down switch D and also in circuit #7 which includes the coil of potential switch P. Therefore, the opening of relay contact 41 interrupts the flow of current in these three circuits which causes the down switch D to drop out, and the potential switch P to drop out thereby breaking the energizing circuit of motor 23 and the stopping of the car. The gate pilot relay GP has also dropped back establishing an auxiliary circuit #9 which comprises L2, lead 28, auxiliary contact 6? of the relay GP, GOR, coil, gate opening limit switch, lead 27 and Li. Passage of current through this circuit causes the gate opening relay GOR to pull in, which in turn establishes a reverse circuit through the gate opening motor (not shown) which automatically opens the car gate and per mits the passenger to enter or exit.

If an intercepting call for the second floor were registered by a party pressing the hall push button 25" before the car arrived at this floor, as the car arrived in the proper stop} ing position for the second floor, the second floor intercepting selector switch it will be pushed to the left by cam IE3" establishing a circuit to Ll through contact ll", stopping selector contacts 3", lead (it, coil of SRi and lead ill. Then when the cam 53 engages roller 7 and operates swi' ch 3 to open the circuit at switch contacts 8" the current is interrupted through the coil of S'Ri and the car comes to a stop at the second floor and the car door is also automatically opened by its motor, in the same manner as above described.

In this arrangement the floor relays are dropped. out in succession in the order that the calls are answered. In the example given, when the car stops at the second floor the cam in raising roller 1 to open switch contact 8 has also raised switch blade 9 closing contact it. A circuit is thus formed from the top of PR2 coil, lead "J3, switch blade it", contact ll, contact It", contact 9", lead 732 to bottom of PR2 coil. Since there is no potential difierence across its coil terminals, the relay FR 2 drops out, thereby cancelling the call for the second floor. A short circuit to LI is prevented by the insertion of the resistors Rt, R2, and Ed in series with the coils of the floor relays F ti to PR5. However, the original call for the first floor has not been cancelled or otherwise disturbed as neither contacts 8" nor ii are in the circuit which registers the first floor call. We have seen in #4 circuit that time relay contact 46 is in series with the coil of the gate pilot relay GP. As the time relay coil winding $8 is energized by current passing through the leads 88, '50 all the time the car is running, relay contact i6 is open during this time, the gate pilot coil relay in the meantime being sustained by current from Ll passing through lead 27, the middle contact 1%" of the GP relay and lead t4. Upon the car stopping and the interruption of current to the time relay coil Bil by the opening of contacts iii 36' of the switch P, contact 26 closes after a time interval because of the action of dashpot device ill. During this interval, the passenger has time to enter or leave the car at the second floor landing and after contact at is again made, the gate pilot coil GP is again energized since the first floor call still remains, causing the armature of GP to pull in and reestablish circuits #6 and #7, causing the car gate to close in the manner above described and allowing the car to proceed to the first floor. The coil of SR is energized through a circuit comprising Ll, lead ll, contact 53 or 54, SR coil, lead 28 and L2. The contact 29 is thus pulled in but not broken, similar to the action of SR previously described, as long as either DR or UR is energized, which is to say, as long as a direction of travel is established. As soon as the last call in the established direction is answered, and the DR or UR coil drops out, SR contact 25 is momentarily opened cancelling any calls that may have come in for the opposite direction of travel leaving the elevator control system free to answer a new call or series of calls.

It is thus seen that the control system described causes the car to stop automatically at the floors in their natural order at which floor push buttons are operated and that the calls are cancelled after the stops are made. It will also be seen that the up and down relays UR and DR are so interconnected that only one may be energized at a time so that after the direction of the car motion has once been established by the first call entered, the car will not answer to any call in the opposite direction. The switches US and DS are safety switches disposed in the hatchway above the level of the top floor and below the level or the bottom floor landings, respectively, and are operated by a cam (not shown) fixed to the car in order to limit its ward and downward motion.

It will be readily understood from the foregoing that in respondlug to an upper floor button from a car position on the first floor, circuits similar to those above described will be established through the up relay UR instead of the down relay DR and through the up switch U contacts 5 1, H, H instead of the corresponding contacts of down switch D. The establishment of these circuits causes the motor 23 to be so energized as to cause the car to travel in the desired upward direction.

The modified form of control system shown in Figs. 3, 4, 5 and 6 is generally similar to that above described and parts in Figs. 5 and 6 which correspond with similar parts in Figs. 1 and 2 are indicated by the same reference characters. In this form or the invention the resistors Rl to R4 (Fig. l) in series with the windings of the floor relays FBI to PR6 are omitted as are also the extra contacts ill to iii" on the stopping selector switches 5. With the car at the third floor, a call entered for the first floor and an interceptive call for the second fioor, the car starts downward with both FEE and F82 relays closed and sustained and the down relay DR closed and sustained as above described in connection with circuits #1, #2 and #3. The coil of stopping relay SR is connected as heretofore described with movable switch contacts 43 of direction relay DR and contact i i of direction relay UR, and the relay SR remains unaffected as long as a direction relay DR or UR remains closed. Circuits l, #5 and #6 are also closed and sustained as heretofore described. When the car arrives in juxtaposition to the second floor, cam 5" operates switch 6 to open the switch contacts 8 thereby interrupting the current through lead 68 and the coil of S'Ri, thus releasing this relay. This interrupts the current through contact ll momentarily and drops off down switch D and potential switch P, thus cutting off current to the motor 23 and stopping the car at the second floor. lhe momentary opening of relay SR! also drops out the gate pilot relay GP since the circuit including lead 4 and the coil of this relay is broken at contact ll. The release of GP relay initiates the car gate opening, time delay and car gate reclosing, as above described. As the first floor tablished direction of car travel was upward,

down relay DR cannot close as long as up relay UR remains closed, since its coil is connected in series with open contact 31 of the up relay.

SR! contact 61 having closed immediately after its momentary opening, causes down switch D j and potential switch P to close after the stopping cycle is completed and the car continues downward to complete its call at the first floor landing.

Having answered the last call in the established direction, cam l9 permits switch 20 to move to the right and break the circuit including contact 2| supplying current to the coil of relay DR causing this relay to open. This breaks the circuit which supplies current to the coil of SR relay at relay contact 43 and causes the movable contact 29 of relay SR to open momentarily due to the dashpot action. The opening of this contact breaks the circuit including leads 35 and 28 which supplies current to the coils of all the fioor relays FBI to FEM causing all the floor relays to release simultaneously and thus cancel all the calls that have been answered also any calls that may have come in for the opposite direction of travel. swered all calls in the established direction of travel in their proper order, the control circuits are now in their initial condition and the elevator is ready to respond to new calls. This system is entirely similar to the first described system, diiiering only in that the floor relays FRI to PR4 are not deenergized as soon as the car arrives at a particular floor, but only after the last call in the established direction is answered, when they are all deenergized together. While the invention has been illustrated as applied to a building having four stories for the sake of simplicity, it will be understood that it is adapted for buildings having a lesser or greater number of floors.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of iioor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch after the starting of the car, and comprising a stopping relay and a circuit for supplying energizing currents to the coils of the floor relays of suflicient strength as to cause the operation of a plurality of said relays in response to the operation of a Having anr plurality of said floor switches, said circuit including a switch operated by the stopping relay.

2. A super interceptive control system as set forth in claim 1 in which the coils of the floor relays are connected in parallel with each other and in series with said stopping relay switch whereby the opening of said stopping relay switch is adapted to interrupt the current to the coil of any of the floor relays.

3. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch alter the starting of the car, and comprising two stopping relays, a switch operated by one of the stopping relays and arranged to deenergize all of the floor relays, a second switch arranged to control the movement of the car and means for moving the second switch in response to the operation of the other stopping relay.

4:. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch after the starting of the car, and comprising a plurality of cams mechanically connected to the car, one for each floor, and means whereby said cams cause the floor relays to become successively deenergized in response to the successive positioning of the car at the corresponding floors.

5. The combination as set forth in claim 4 in which the last named means comprises a plurality of control circuits adapted to connect the opposite terminals of the relays, each of said control circuits including a switch adapted to be operated by one of said cams.

6. The combination as set forth in claim 4 in which resistors are connected to one terminal of the floor relays, the outer ends of said resistors being continuously connected to a source of potential supply.

'7. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch after the starting of the car, and comprising a directional relay, a directional switch coil, a potential switch coil, a stopping relay having its switch contact connected in series with said directional and potential switch coils and a source of potential, a plurality of stopping selector switches connected to the coil of said stopping relay, a plurality of cams mechanically connected to the car and arranged to successively operate said stopping selector switches, a second stopping relay having its coil connected in series with the contact of said directional relay and having its contact connected in series with the contact arms of the floor relays.

8. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch after the starting of the car, and comprising a. rotatable shaft, means for rotating said shaft through an angle proportional to the movement of the car, a plurality of cams secured to said shaft, one for each floor, a plurality of switch blades arranged to be successively actuated by said cams in response to the successive positioning of the car at the corresponding floors and circuits connecting said switch blades to the opposite terminals of the floor relays whereby the closure of said switch blades causes the opposite terminals of the fioor relays to assume the same potential, thereby releasing said relays.

9. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, re-

gardless of the order in which said switches are operated, said controlled means comprising a plurality of cam operated switch devices arranged to short circuit the windings of the floor relays successively in response to the positioning of the car at the corresponding floors.

10. A super interceptive system for controlling an elevator car comprising, in combination, a plurality of floor relays, one for each of a plurality of floors, means including a switch at each floor for operating said relays, means controlled by said relays for operating the car in an established direction, stopping and automatically starting the car at the floors at which switches are operated, in the natural order of floors, regardless of the order in which said switches are operated, said controlled means being arranged to prevent the starting of the car in a direction opposite to the established direction in response to the operation of a floor switch after the starting of the car, and comprising a stopping relay having a movable contact, a directional relay having a movable contact, an energizing circuit arranged to connect the contact of the directional relay in series with the coil of the stopping relay and a circuit arranged to simultaneously energize and hold a plurality of the floor relays, said circuit having the movable contact of the stopping relay in series therewith, and means for maintaining the directional relay energized until the car has arrived at the last floor in the established direction and for deenergizing said directional relay at said last floor, whereby the release of the directional and stopping relays causes the floor relays to be simultaneously released.

MORTIMER A. MYERS.

Images