US1925873A - Automatic elevator system - Google Patents

Description

Sept. 5, 1933. F. E LEw|$ 1,925,873

AUTOMATIC ELEVATOR SYSTEM Filed Sept. 25, 1927 INVENTOR WITNESSES: Fldflk Lewis A ALI'TORNEY Patented Sept. 5, 1933 UNITED STATES PATENT OFFICE AUTOMATIC ELEVATOR SYSTEM Application September 23, 1927 Serial No. 221,415

17 Claims.

My invention relates to control systems for motor driven apparatus and has special reference to control systems for elevators, hoists and similar machinery.

An object of my invention is to provide a control system for an elevator which is entirely automatic in its operation.

Another object of my invention is to provide a control system for elevators wherein the normal operation of an attendant-controlled-elevator will be duplicated, without the necessity of any manual intervention.

Another object of my invention is to provide a control system for elevators for use in public buildings wherein the elevators will be automatically dispatched from a terminal floor and will thereafter make a complete trip up or down or both; stopping to receive and discharge passengers without requiring the presence of an attendant on the car.

Another object of my invention is to provide a control system for elevators wherein an automatic dispatching device will automatically cause an elevator car to start from a selected terminal at predetermined periods of time.

My invention will be described with reference to the accompanying drawing wherein the sole figure is a diagrammatic view of an elevator system organized for automatic operation in accordance with the principles of my invention.

Referring to the drawing, there is illustrated a cable Ca for supporting an elevator car (not shown). The cable Ca passes over a hoisting drum D to a suitable counterweight Cw. A variable-voltage driving equipment for operating the hoisting drum D is illustrated as comprising a'motor EM having an armature EM and a separately excited field winding EMF. The motor armature EM is directly coupled to the hoisting drum D and is electrically connected in circuit with'the armature G of a generator G. The generator G is preferably of the compound wound'type including a series field winding GSF andseparately excited field winding GF and a demagnetizing field winding GAF. The armature G of the generator G is directly coupled to the armature M of a driving motor M which motor is equipped with a shunt field winding ME.

The direction and speed of operation of the elevator motor EM isv controlled in the usual manner by controlling the excitation of the generator separately excited field winding GF. This is accomplished through the operation of an up direction switch 1 and down direction switch 2 and one or more speed relays 3.

The embodiment of my control system disclosed shows my control apparatus applied to an elevator operable between. four floors. At each'of the floors intermediate the terminals, that is, at the second and third floors, there is provided an up button and. a down button for causing the car to stop at the associated floor when traveling in the up or downdirection, dependent upon which of the buttons at the floor has been operated. These buttons are similar to those usually provided in elevator systems for signalling toan attendant on the car that a person desires-to board the car. at the floor at which such button is operated. The up button for the third floor is..designated by the reference character 3U, the down button for this floor by the reference character 3D while the up button for the second floor is designated by the reference character 2U and the down button for the second floor by the reference character 2D. Associated with each of the. push-buttons is a push-button relay, these relaysbeing designated by the reference character 3RU, 3RD, 2RU, 2RD to correspond to the up and down buttons for the third and second floors, respectively. Associated with each of thepush-button relays is a reset relay, these relays-being designated by the characters 3SU, 3SD, 2SU and 2S-D,rrespectively.

A push button for'each of the floors intermediate the terminal floors is mounted on the elevator car. The buttons correspond: in function to the buttons 3U, etc., mounted. at the various floors and are designated by the reference characters 20 and corresponding to the floors with which the buttons are associated. These buttons are of the type disclosed in Patent No. 1,839,629, granted January 5, 1932, to H. W. Williams and assigned to the Westinghouse Electric & Manufacturing Company.

Floor lanterns, such as are ordinarily used with elevator systems for signalling to persons waiting to board the elevator that the car is approaching and for indicatingthe direction in which the elevator is traveling, may be associated with my elevator control system and are designated in the drawing by the characters 4L1), 3LU, SLD, 2LU, 2LD and lLU to correspond with the floor and direction of operation with which each ofthese lamps is associated.

For causing the floor signal lanterns to be illuminated as the car approaches the associated floors and for causing the car to stop when it arrives adjacenta floor for which a push button-has beenoperated', I have provided afloordoors.

selector FS which may be of the type usually used to control the signal circuits for elevators. The floor-selector illustrated comprises a suitable base upon which are mounted a plurality of series of contact segments. These segments are divided into groups corresponding to the signal and control devices with which they are associated. The groups of contact segments are designated respectively by the characters AU, BU, CU, DU, AD, BD, CD, and DD. A set of contact brushes one for each of the groups of contact segments and designated by similar primed reference characters AU, BU, CU, DU, AD, BD, CD and DD are mounted upon a movable arm A for movement over their associated groups of contact segments in; correspondence with movements of the elevator car in its travel from one of its terminals to the other. The movable arm A may be driven in the usual manner by some movable part of the elevator hoisting mechanism and is illustrated as being operated by a screw S connected for rotation bythe hoisting mechanism. By reason of the frictional engagement between the arm 'A and the screw S, the direction of movement of the elevator car will determine which of the sets of contact brushes (those whose reference characters end with the letter U or those ending with the letter D) will be moved into contact with the corresponding contact segments.

Suitable doors, such as are usually provided in elevator control systems, are illustrated and designated by the reference characters D1, D2, D3 and D4, one of such doors being associated with each of the floors past which the elevator travels.

For automatically opening and closing these doors, suitable door operating devices D01, D02, D03 and D04 are shown associated respectively with the first, second, third and fourth floor These door opening and closing devices may be of any suitable type wherein the door is given a positive movement to both open and closed positions. The door operating devices are illustrated diagrammatically as embodying a lever 10 pivoted at 11, secured to the door as at 12 and operated about its pivot 11 by the energization of either of two solenoid type magnets 13 and 14. The energization of the solenoid 13 will cause the door to move in the direction of the arrow X to open the door, while the energization of the solenoid 14 will move the lever 10 to cause the door to assume its closed position.

In order that the doors, when opened, shall remain open for a predetermined time, a timed re- -lay 15 is connected as hereinafter described to control the circuit for the door closing solenoid 14. The relay 15 is provided with some means such as a dash-pot 16 for retarding its movements toward closing position for an adjustable period of time.

A series of relays 20, 21, 22 and 23 are associated with the controlling circuits for slowing 7 down and stopping the elevator car as is hereinafter described. The relays 20 and 21 have their coils connected respectively for operation by the 1 up floor buttons and the car buttons, while the relays 22 and 23 are connected for actuation by the down floor buttons and the car buttons respectively.

A pair of direction-determining relays 24 and 25 are provided for causing an automatic reversal of the elevator car upon the arival of the car at the terminal floors. A relay 26, having its coil in circuit with each of the door switches 27, one of which is provided for each of the doors and having its contact members arranged for controlling the energization of the direction switches 1 and 2, is provided for starting the car after each stop has been made. A relay 28, having its coil connected across the terminals of the elevator motor armature EM, is provided for controlling the speed of the elevator car and a relay 29, having its coil connected for actuation by a dispatching contactor 30, controls the closing of the door at the first floor or dispatching point in the elevator system. The dispatching contactor 30 is driven by any suitable timed-mechanism, such as a motor 31, to produce an impulse of current at regular intervals of time.

My system will best be understood with reference to an assumed operation. Assuming the elevator car to be at the lowermost terminal, that is, the first floor, the car in this position engages a cam-actuated-switch DL, preferably of the usual limit-switch type, to hold the contact members 36 of the switch in open circuit position. This operation deenergizes the direction-determining relay 25 and permits the energization of direction-determining relay 24. The circuit for direction determining switch 25 extends from line conductor Ll through conductor 37, the normally closed contact members 36 of the switch DL, conductor 38, the coil of direction-determining switch 25 normally closed contact members a of direction-determining switch 24, conductor 40 to line conductor L2. The circuit for the switch 25 will, therefore, be open at the switch DL. Switch 25, upon dropping out, closes its contact members (1 thereby completing a circuit for energizing switch 24 which circuit extends from line conductor L1 through conductor 41, the normally closed contact members of a switch UL (which switch is a duplicate of the switch DL and is mounted in the upper portion of the hatchway for engagement by the elevator car when the car arrives at the uppermost or fourth floor) conductor 42, normally closed contact members a of the direction-determining switch 25, and coil of direction-determining switch 24 to line conductor L2.

Direction-determining switch 24, in closing, partially completes a circuit for the up directionswitch 1, which circuit, however, can not be completed until the relay 26 is energized. The circuit for the direction-switch 1 extends from the line conductor L1 through the normally open contact members of relay 26, conductor 45, the coil of updirection-switch 1, conductor 48, the normally opened contact members c of direction-determining switch 24, normally closed contact members c of relay 28 and conductor 51 to line conductor L2.

In order that the door for the first floor shall be opened when the car is standing at that floor, it is assumed that as the elevator car approached the first floor, it engaged and closed a switch 55 for supplying current to the door opening solenoid 13 associated with the door D1. The circuit for the door opening solenoid 13 extends from the line conductor L1 through conductor 56, normally closed contact members 0 on the speed relay 3, (now deenergized) conductor 58, contact members 59 of the switch 55, conductor 60, the coil of solenoid 13, and conductor 61 to line conductor L2. The door D1 will be opened permitting the passengers on the car to leave the car at the first floor.

When the dispatching-contactor 30 is actucircuit energizing relay 29, which circuit extends fromlineconductor L2 through conductor 62, the shaft 63, contact disc 64-and brush 65 of the dispatchingcontactor 30, conductor 66, and the coil of "relay 29 to line conductor L1.

- Relay 29,- when energized, completes a circuit for the door-closing solenoid 14 associated with the door D1 which circuit extends from the line conductor L1 through conductor 68, the normally open contact-members of relay 29, conductor 70, contact members 71 of switch 55, conductor 72, the coil oi doorclosing solenoid 14 and conductor'61 to line conductor L2. The door D1 is thus closed.

Assuming the usual condition that all of the doors associated with the hatchway except the one at which the car is standing, that is the first floor, are closed, the subsequent closing of the firstfloor door D1 will complete a circuit for the relay 26'through the door switch 27 associated withthis door, which circuit extends from line conductor L1 through conductor 73, the coil of relay 26; conductor 74, the series door switches 27 and conductor 76 to line conductor L2.

The energization of relay 26 completes the circuit for up-direction-switch 1 which circuit has been previouslytraced. The up-direction-switch 1, now energized, completes the circuit for excitingthe-generator separately-excited-field-winding GF with current in one direction. This circuit extends from the line conductor L1 through conductor 75, normally open contact members a ofthe up-direction-switch '1, the separately-excited-field-winding GP for the generator G, and aresistor 80, conductor 81, normally open contact members b on the up-direction-switch 1 and conductor 83 to line conductor L2.

It is assumed that according to the usual connection of generator-motor driving sets that the separately-excited-field-winding EMF for the elevator-hoisting-motor EM is continuously energized through cono'luctors 84 and 85 connecting line-conductor L1 and line conductor L2 to opposite ends of the separately-excited-field-winding EMF, respectively. Therefore, the energization of the field-winding GP for the generator G causes the elevator motor EM to start and lift the elevator car.

The up-direction-switch 1, when energized, completes the self-holding circuit to maintain theswitchin operated condition, which circuit extends from'line conductor L1 through the contact'memb'ers of relay 26, conductor 45, the coil of up-direction-switchl, normally open contact members I of the up-direction-switch 1, conductor 87,'normally closed contact members of an inductor relay 89 carried by the elevator car and conductor 90 to line conductor L2. Thus, the elevator car will be caused to continue its upward movement until the inductor relay 89 is actuated as hereinafter described to open its contact members.

The up-direction-switch 1 when energized also energizes the. coil of'speed relay 3 by way of a circuit which extends from line conductor L1 through the coil of. speed relay 3, contact members .dof switch 1, conductor 94, normally closed contact members I) of the relay 28, normally closed contact members a of each of the relays 20, 21,,22- and 23, in series relation, and conductor 96 to line conductor L2.

Thehenergization ofspeed relay 3 causes the contact members b of relay 3 to short-circuit the resistor80 thus increasing the excitation voltage supplied to the generator-field-winding GF, and consequently causing'the elevator motor EM to operate ataspeed higherthan itsinitial speed. At the same time, the contact memberssa of the speed relay3 will close a self-holding circuit for this relay which circuit extends as previously traced through contact members d of switch l, and thence by way of conductor97, contact members a of the speed relay 3, conductor 98, normally closed contact members of a slow-down! inductor relay 101, conductor 100, normally closed con-. tact members of another slow-down inductor relay' 99, conductor 102 to line conductor L2. Thus,it is seen that the speedrelay 3, when once operated, will be maintained in its operative position until one or the otherof the inductor relays 99 or 101has been actuated to open its associated contact members.

The inductor relays, such as are illustrated in my system at 89, 99 and 101, are preferably of the type disclosed in the copending application of H. W. Williams, Serial No. 190,482, filed May 11, 1927, wherein a switch and a coil are so mounted upon the elevator car that energization of the coil is ineffective to cause actuation of the switch until the coil is brought adjacent-a magnetizable iron plate mounted in the hatchway in which the elevator car operates. At such time, the energized coil is rendered eiiective tooperate its associated switch. While I have illustrated inductor relays as a means for controlling the holding circuits for the speed and direction switches, it is obvious that other forms of switches may be substituted for the switch shown. The only essential conditions being that the switch must not open its contact members until the-car arrives adjacent a predetermined point in the hatchway, and that the efiective actuation of the switch dependsv upon a push button corresponding. to the floor at which the elevator car is to stop having been operated.

I have illustrated diagrammatically, a series of magnetizable iron plates 89, 99 and 101 for cooperation, respectively, with the, several inductor relays 89, 99 and 101. It will be understood that a similar series of plates is provided for each floor'served by the elevator.

Relay 89 constitutes a stopping switch, and is effective to interrupt the directional circuit for both directions of car travel.

The relay 99 constitutes a down slow-down switch, while the relay 101 constitutes an up slow-down switch.

The arrangement. of the inductor relays 89, 99, and 101 and their respective magnetizable plates is disclosed in a copending application of E. M. Bouton, Serial No. 731,921, filed August 14, 1924, Systems of control, which application shows an arrangement whereby the inductor relaysare so mounted upon the car and the plates are so mounted in the hatchway that the respective switches will be operated at such points in l the travel of the car that the elevator will be decelerated and brought to a stop level with the associated floor.

Assuming, for example, that a person on the second floor desires to travel upwardly and operates the floor push button 2U, circuits will be set up to cause the car to automatically stop at the second floor to take on the passenger. The operation of the push button 2U completes a circuit for the push button relay'2RU which circuit extends from line conductor L1, the push button 2U, conductor 105, the coil of push button relay ZRU, conductor 106, normally closed contact members of reset relay 2SU, conductors 107 and 108 to line conductor L2: Energization of push button relay 2RU completes a self-holding circuit for this relay by way of conductors 109, contact members a of relay 2RU and conductor 110.

Contact members b of the relay 2RU partially completed a circuit for the energization of the relay 20 which circuit extends from line conductor L1 through contact member b of relay 2RU, conductor 112 to contact segment 113 of the group BU on the floor selector FS.

1 As the elevator car approaches the second floor, the brush BU on the arm A of the floor selector FS will engage and bridge contact segment 113 and contact strip 114, thus completing the above partially traced circuit for the relay 20 by way of conductor 115, the coil of relay 20 and conductor 116 to line conductor L2. The relay 20 when energized opens its contact members a, which as will be recalled, are in the circuit for the energizing coil of the speed relay 3. The function of these contact members will be hereinafter described. The relay 20 also closed its contact members b to complete a circuit for the energization of up slow down inductor relay 101 which circuit extends from line conductor L2 through conductor 117, contact members I) of relay 20, conductor 118, the coil of inductor relay 101, conductor 120, the coil of inductor relay 89, and conductor 122 to line conductor L1. Thus, as the elevator car passes the magnetizable plates 101' and 89', the inductor relays 101 and 89 will be successively actuated to cause the car to slow down and to stop at the second floor. The actuation of relay 101 will occur somewhat prior to the actuation of relay 89 by reason of the arrangement of the inductor plates 101' in advance of the plate 89. As previously described, the holding circuit for the speed relay 3 will be broken upon actuation of the relay 101 causing reinsertion of resistor in circuit with the generator-separately-excited-field-winding GF and the opening of contact members of relay 89 will cause deenergization of theup-direction-switch 1.

In order to cause the elevator car to stop accurately level with the floor landing, the demagnetizing-field-winding GAF is connected in series with normally closed contact members c on both of the direction switches 1 and 2. This circuit extends from conductor 123 connecting the motor armature EM with the generator G through conductor 124, the demagnetizing-fieldwinding GAF, resistor 125, conductor 126, normally closed contact members 0 on up-directionswitch 1, conductor 127, normally closed contact members 0 on down-direction-switch 2, and conductor 128 to conductor 129 which connects the opposite terminals of the motor armature EM and the generator armature G. The demagnetizing-field-winding GAF is thus excited to oppose the excitation of the normal field of the generatory In this manner, the opening of the direction switch 1 causes complete demagnetization of the generator field and reduces the voltage supplied to the motor EM to zero within a time period inversely proportional to the load on the motor, in the manner disclosed in a patent to E. M. Bouton, No, 1,734,198, granted November 5, 1929, and assigned to the Westinghouse Electric and Manufacturing Company.

As the car arrives substantially level with the second floor, switch 130, similar to the switch 55 previously described is actuated by the presence of the elevator car. This switch connects "the door opening and closing solenoids 13 and 14 associated with the door D2 for the second floor, thereby permitting voltage to be supplied to the door opening solenoid 13 upon deenergization of the speed relay 3. This circuit extends from line conductor L1 through conductor 56 normally closed contact members 0 of speed relay 3, conductor 58, contact members 131 of the switch 130 conductor 132, the coil of door opening solenoid 13 associated with door D2 and conductor 61 to line conductor L2. The door D2 is thus opened automatically as the car slows down to make the stop at the second floor. By so connecting the door opening solenoid 13 with the speed relay 3, a great saving in time is accomplished since the period of deceleration is utilized for opening the doors and as the car arrives level with the floor, the door opening devices can be so adjusted that the door will be completely open when the car stops. Moreover, a door will not be opened unless the car is decelerating to stop at the associated floor.

The passenger boards the car at the second floor and after a predetermined time, for example, 3 to 5 seconds, the relay 15 will be actuated to energize the door closing relay 14 for the door D2. In order to operate the relay 15 at the proper time the door D2 when moved to its extreme open position, a contact member 134 carried by the door engages a contact member 135 stationarily mounted on the hatchway structure to complete a circuit for the relay 15, which circuit extends from line conductor L2 through conductor 136, contact member 135, contact member 134, conductor 137, the coil of relay 15, conductor 138 to line conductor L1. The energization of relay 15 causes it to close its contact members to complete a circuit for the door closing solenoid 14, which circuit extends from line conductor Ll through the contact members of relay 15, conductor 140, contact members 142 of the switch 130 (suitably insulated as at 143 from the contact members 131) conductor 144, the door closing solenoid 14 and conductor 61 to line conductor L2. The closing 01' relay 15 is retarded as previously described for the necessary time by means of the dash pot 16, thereby allowing the passenger ample time in which to board the elevator.

As the elevator car approached the second floor level, the second-floor up-signal-lamp 2LU was energized by way of a circuit which extends from line conductor L1 through contact members b of relay 2RU, conductor 112, contact segment 146, contact brush AU on the floor selector arm A, contact segment 147, conductor 148, signal-lamp 2LU and conductor 149 to the line conductor L2. This actuation of the signal-lamp 2LU indicates to the person waiting at the second floor that the car is approaching the second floor and is traveling in the up direction.

As the car arrives level with the second floor,

the contact brushes CU on the floor selector I arm A bridges contact segment 151 and contact strip 152 thus completing a circuit for energizing reset relay 2SU to cancel the call initiated by the actuation of the button 2U. This circuit extends from line conductor L2 through conductor 153, contact strip 152, contact segment 151, conductor 154, the coil of reset relay 2SU and conductor 155 to line conductor L1. The actuation of reset relay 2SU opens the holding circuit previously traced for the push button relay 2RU permitting deenergization of relay 2RU and relay 20.

The closing of the door D2 after the passenger has boarded the elevator car permits re-energizationof up-direction-switch 1 and speed relay 3 as previously. described for theinitial starting of the elevator car, which accordingly restarts and continues its upward travel. The direction determining switch 24 remains energized as previously described until the car arrives at the uppermost terminal so that it follows that the closing of the doors causes actuation of the same direction switch which had been functioning prior to making the stop at the floor.

Assuming that the person who boarded the car at the second floor desires to travel to the third floor he operates the button 30 on the elevator car. This operation completes a circuit for the energization of relay 21 to thus cause the car to stop upon its arrival level with the third floor. This circuit extends from the line conductor L1 through push button 36, conductor 157 to contact segment 159 in the group DU on the floor selector FS. As the elevator car approaches the third floor, the contact brush DU bridges contact segment 159 and contact strip 160 to complete the circuit for the relay 21 by way of conductors 161, relay 21, and conductor 162 to line conductor L2. The actuation of relay 21 closes the circuitfor energizing the up slow down relay 101 and the inductor stop relay 89, which circuit extends from line conductor L2 through conductor 117, contact member b of the relay 21, conductor 118 and thence, as previously traced for the relays 101 and 89. The elevator car will be decelerated and stopped level with the third floor and the door D3 associated with the third floor will be opened through the agency of a switch 158. All of the above operations will be effected in the same manner as that described for the second floor stop. After the predetermined time, fixed by the adjustment of relay 15, the door at the third floor will be closed and the car will continue on its way upwardly.

With modern high speed elevator equipment, the zone through which the elevator must be decelerated from its high speed operation in order to make a stop at a floor extends somewhat beyond the level of the adjacent floor. Under these conditions, the contact segment 159 will slightly overlap, in position, the contact segment 113 with the result that when the car is standing at the second floor and a third floor button is operated, the relay 21, (20, 22 or 23) will be immediately energized. For the purpose of preventing the elevator car from being accelerated to its highest speed under this condition of making a one floor run, I have shown the circuit for the speed relay 3 as extending in series relation through normally closed contact members aon each of the relays 20, 21, 22 and 23. Thus, when a car is standing at one floor and circuits are set up for causing the car to stop at the next adjacent floor, the speed relay 3 is prevented from operating and the motor will thus be prevented-from operating at high speed for this short run.

'While no push buttons have been shown at the top and bottom floors, it is understoodthat buttons may be supplied for these floors or as will probably be best, the elevator car will be stopped at the terminal floors through the actuation of the usual slowdown and stop limit switches provided at the ends of the travel. I have illustrated the stopping means for the elevator car at the top and bottom floors as comprising limit switches formed of contact mem bers on the floor selector. The car will be stopped at the fourth floor when the brush DU engages and bridges contact strip 160 and contact segment 180. As will be seen from an inspection of the drawing, the contact member 180 is connected at all times to line conductor L1 by way of conductors 155 and 181 and in this manner the contact segment 186 will be continuously energized. Similar contact segments in the groups AU and BU are provided connected to the. supply conductor L1 to cause the actuation of the relay 20 to stop the car at the fourth fiOOl and to light the floor lantern 4LD as the car approaches this floor.

A similar series of contact segments are provided for the first floor in groups AD, BD and DD to cause similar operations as the car approaches the lower limit of travel.

As the car arrives at thefourth floor, it will engage operate the switch UL to cause the opening of the circuit for the up-direction-determining-switch 24, thus causing switch 24 to be deenergized and through contact members a on switch 24 causing the energization of down-direction-determining-switch 25. The door D4, through the agency of a switch 141, is caused to open, and, subsequently, to close, as described for the second and third floors.

Upon closing the door at the fourth floor,'the downdirection-switch 2 and the speed relay 3 will be energized in the same manner as described for the up-direction-switch. 1 and the car will start downwardly, stopping at the several floors traversed by the car in response to the operation of the corresponding push buttons 3D and 2D. The operation of the buttons 2D and 3D and their associated push button relays, reset relays etc. are identical with the operations described for the up trip and are, therefore, not described in detail.

The push button relays 3RD and 2RD are arranged to actuate the relay 22 corresponding to the relay 20, while on the down trip, the actuation of the car buttons 30 or 2C will cause operation of the relay 23. As will be noted, the

arm A of the floor selector F5 can engage only the contact segments of the AD, BD, CD, and DD groups when the car is traveling downwardly, therefore, the same push DlllJtOIlS on the car 2C and 3C may be used for operating either relays 21 or 23 and the relay which will be operated is determined by the direction in which the car is traveling.

As a means for maintaining the pushbuttons 2C and 3G in operated condition when operated, I have provided hold down coils 162, the circuit for which is closed at all times, except when the elevator car arrives at either of its terminals whereupon the circuit is momentarily broken during the transition period between the operation of directiondetermining switches 24 and 25. The circuit for the hold-down coils 162 extends from the line conductor L1, through these coils, inseries, conductor 165 and the contact members b of relays 24 and 25, in parallel, to line conductor L2. It will thus be seen that during the time that either of the direction determining switches 24 and 25 is energized, the circuit will be maintained for the coil 162, but during the period between which the relay 24 is deenergized and the relay 25 becomes energized, the circuit will be broken. Thus all buttons which have been operated will be restored at the .end of each trip.

While I have illustrated only one elevator in 150.

plicable to installations comprising a number of elevators. The adoption of my system for a number of elevators comprises merely a parallel connection between the floor push buttons 2U and 2D, etc. to the floor selectors associated with additional elevator cars. Such parallel connections are illustrated at 175. The dispatching contactor may be provided with additional contact members for each car.

It will thus be seen that I have provided an elevator system which is entirely automatic in its operation, the car or cars will be dispatched automatically from a terminal floor at predetermined intervals of time and the car so dispatched will, thereafter make a complete round trip or part trip, stopping to take on and discharge passengers in exactly the same manner as though an attendant on the car controlled the operations of the elevator.

While it has been assumed in the foregoing description that the elevator car will always make a complete round trip, it is obvious that by suitable arrangement of the switches UL and DL controlling the direction determining switches 24 and 25, the car may be caused to travel only between any selected number of floors. For example, in a building having a basement first floor and a number of upper floors, it may be desired to have the elevator travel normally only between the first and the upper floors. The switches UL and DL can be arranged to cause the elevator to travel only between these floors.

While I have thus far described only one dispatching contactor 30 for starting the car from the first floor, the car may be dispatched from both the first and the fourth floors. The only alteration required for this latter operation consists in connecting the fourth-floor door-closing coil 14 for energization through either the contact members of relay 15, as previously described, or through the contact members of a second dispatching relay 29'. Relay 29 is, in turn, suitably controlled by means of a second dispatching commutator 1'76, in the manner described for commutator 30. A switch 1'77 may be employed to efiect the change. Thus, the elevator car would be automatically started from the first fioor,

would automatically make a complete up-trip and wait at the upper terminal for a down dispatching impulse. Upon receiving the down dispatching impulse, the car will start and make a complete down-trip.

. My invention is illustrated and described herein only in diagrammatic form and I do not desire to be limited to any of the details shown therein except as defined in the appended claims.

I claim as my invention:

1. In a vehicle control system a vehicle operable over a predetermined path past a plurality of stations, a closure at each station, means for automatically closing the closure at a selected one of said stations and for automatically starting said vehicle from said station at predetermined intervals of time, selectively operable means'for automatically stopping said vehicle at said stations and for automatically opening the closure at said station, means for closing said closure after a predetermined interval of time and means responsive to the closing of said closure for causing said vehicle to continue its travel past the remaining stations and back to the starting point.

2. In an elevator control system an elevator operable over a predetermined path past a plurality of stations, a closure at each station, means for automatically closing the closure at a selected one of said stations and for automatically starting said elevator from said station at predetermined intervals of time, selectively operable means for automatically stopping said elevator at said stations and for automatically opening the closure at said station.

3. In an elevator control system an elevator operable past a plurality of floors, a door at each floor, door opening and closing devices for each door, means responsive to the approach of said elevator to any of said floors for rendering operative said door opening device for that door and for conditioning the door closing device for that floor for operation, and timed means for.

rendering said conditioned door-closing device operative at the expiration of a predetermined time.

4. In an elevator control system, an elevator operable past a plurality of floors, a door at each floor, electric door opening and closing devices for each floor switch means operably responsive to the approach of said elevator at any of said floors for causing operation of said door-opening device for that door and for partially completing the circuit for the door-closing device for that floor, and timed means for completing the circuit for said door-closing device at the expiration of a predetermined time.

5. In a control system for an elevator operable past a plurality of floors between two terminal floors, starting mechanism for said elevator, a door at each floor, closing mechanism associated with each of said doors, means comprising a dispatching device for actuating said closing mechanism to close the door at one of said terminal floors and for actuating the starting mechanism for said elevator, said dispatching device being operable at predetermined regular intervals of time, selectively operable means for stopping said elevator at said floors, opening mechanism associated with each of said doors and responsive to the stopping of said elevator at any of said floors for opening the door at that floor, and means responsive to the reclosure of that door for causing said elevator to restart and travel to said other terminal floor.

6. In a control system for an elevator car operable past a plurality of floors, a door at each of said floors, closing mechanism associated with each of said doors, means comprising a dispatching device operable at predetermined regular intervals of time for actuating the closing mechanism for the door at one of said floors, starting mechanism adapted upon closure of that door for starting said elevator, selectively operable means for stopping said elevator at each of said floors, and means responsive to the stopping of said elevator at any of said floors for opening the door at that floor.

7. In a control system for an elevator car operable to and from a floor, motive means for said car and switching mechanism operable to effect the starting of said motive means, a timing device having a predetermined timing interval, and means including a switch responsive to the approach of said car to said fioor for rendering said switching mechanism operably responsive to said timing device.

8. In a control system for an elevator car operable to and from a floor, means for starting said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, and means responsive, when said car is at said floor, to said operation for actuating said starting means.

9. In a control system for an elevator car operable to and from a floor, means for starting said car, a timing switch, means adapted to cause successive operations or" said timing switch at predetermined intervals of time, means adapted to respond to an operation of said timing switch for actuating said starting means, and means for rendering said starting means non-responsive to said operation of said timing switch, said last named means comprising a switch responsive to the position of said car with respect to said floor.

10. In a control system for an elevator car operalole to and from a floor, a first switch operable in response to the approach of said car to said floor, a second switch, means adapted to cause successive operations of said second switch at predetermined intervals of time, and means including switching mechanism controlled jointly by said first and second switches for causing the starting of said car.

11. In a control system for an elevator car operable to and from a floor, motive means for said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, and means in cluding a switch responsive to the approach of said car to said floor for rendering said motive means subject to control by said timing switch.

12. In a control system for an elevator car operable to and from a floor, means including switching mechanism operable to effect the starting of said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, and means including a switch responsive to the approach of said car to said floor for rendering said switching mechanism operably responsive to an operation of said timing switch.

13. In a control system for an elevator car operable to and from a floor, motive means for causing movement of said car in either of two directions, means responsive to the approach of said car to said floor from one of said directions to condition said car to leave said floor in the 0pposite direction, a timing device having a predetermined timing interval, and means actuated by said timing device at the expiration of said interval for causing said motive means to start said car away from said floor in said opposite direction.

14. In a control system for an elevator car operable to and from a floor, motive means for causing movement of said car in either of two directions, starting means for said motive means, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, and means including switching mechanism responsive to the approach of said car to said floor for rendering said starting means operably responsive to said timing switch and for causing the direction of movement of said car to be in a direction opposite to the direction of approach.

15. In a control system for an elevator car operable past a plurality of floors, motive means for said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, means responsive to the approach of said car to a selected one of said floors for rendering said motive means responsive to an operation of said timing switch to eiTect the starting of said car from that floor, manually operable switches associated with each of said floors, and means responsive to the operation of any of said switches for controlling said motive means to effect the stopping of said car at the associated floor.

16. In a control system for an elevator car operable past a plurality of floors intermediate two terminal floors, motive means for said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, means responsive to the approach of said car to one of said terminal floors to render said motive means responsive to said timing switch to effect the starting of said car from that floor and to bias said motive means to cause said car to travel to the opposite terminal floor, manually operable switches associated with each of said intermediate floors, and means responsive to operation of any of said manually operable switches for controlling said motive means to effect the stopping of said car at the associated floor.

17. In a control system for an elevator car operable past a plurality of floors intermediate two terminal floors, motive means for said car, a timing switch, means adapted to cause successive operations of said timing switch at predetermined intervals of time, means responsive to the approach of said car to one of said terminal floors to render said motive means responsive to said timing switch to effect the starting of said car from that floor, manually operable switches associated with each of said intermediate floors, means responsive to operation of any of said manually operable switches for controlling said motive means to eifect the stopping of said car at the associated floors, and means rendered eiiective by the initial starting of said car from said one terminal floor for controlling said motive means to effect the restarting of said car after each stop at an intermediate floor.

FRANK E. LEWIS.

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