US2699227A

US2699227A - Elevator system having plural operating modes

Info

Publication number: US2699227A
Application number: US300388A
Authority: US
Inventors: William F Eames
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1952-07-23
Filing date: 1952-07-23
Publication date: 1955-01-11
Anticipated expiration: 1972-01-11

Description

Jan. 11, 1955 W. F. EAMES ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES Filed July 25, 1952 6 Sheets-Sheet 1 Door Contocs HC X WITNESSES:

BMS B7OT Contacts SR2 000| A'Avn/ BHC BXB L2 INVENTOR William F.Eomes.

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ATTORNEY' Jan. 11, 1955 W. F. EAMES ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES W. F. EAMES Jan. 11, 1955 ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES Filed July 23, 1952 6 Sheets-Sheet 4 mom l mom zmom mom 6m l l lvg Jan. 11, 195s W. F. EAMES ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES Filed Julyr23, 1952 6 Sheets-Sheet 5 ATTORNEY w. F. EAMES Jan. 1'1, 1955 ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES Filed' July 23, 1952 6 Sheets-Sheet 6 A .v01 l E61 m2o: R m :or MW m o n zu: m E DN V F O m m n mom No-v|e\.na- .m A mom Ieper 2am m8 am 28 DQ. $52. 2. .SYS. D- NDJ mm3. @DN NIDNMVIG mmDN .rmx D mw c ma o wc Tlvo s SL.; Y s Eilllllllll IIIII Illlllllmwllsi l mi .n. v EIII.||.|.||||||||.||||.|...|||||.||||| vllqlm Q 6&5. MU EN RSN 2123 w s mon um e\ TES m n uw|n1\-w .$23 w a. M v f. J

United States Patent C ELEVATOR SYSTEM HAVING PLURAL OPERATING MODES William F. Eames, Westfield, N. J., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application July 23, 1952, Serial No. 300,388

33 Claims. (Cl. 187-29) This invention relates to an elevator system having plural operating modes and it has particular relation to banks of elevator cars having oeprating modes which are automatically selected to provide service best suited for varying traffic patterns.

Although aspects of the invention are suitable for elevator systems consisting of a single elevator car, the invention is particularly suitable for banks of elevator cars. For this reason, the invention will be discussed largely with reference to a bank of elevator cars.

In accordance with the invention, an elevator system is arranged to provide a first mode of service. However, underd certain conditions, the elevator system automatically is transferred or converted to a second mode or a specialized service. In a bank of elevator cars, the nurnber of cars transferred to the second mode of operation may depend on a factor such as the service demand. In a preferred embodiment of the invention, the service demand is measured by the number of car calls registered for landings or floors desired by passengers entering the elevator cars.

As an example of a suitable first mode of operation, the elevator cars may be arranged to operate between terminal landings or iioors in order to provide service not only for the terminal floors but for a plurality of intermediate landings or floors located between the terminal floors. Should a large number of car calls be registered in one of the elevator cars by passengers entering the car at the lower terminal floor, the car would require a substantial time to deliver the passengers and to return to the lower terminal oor. Under these cir cumstances, the car may be transferred for operation in accordance with the second mode.

As illustrative of the second mode of operation, the elevator car when transferred thereto may be conditioned to reverse at the farthest call for service in the direction of the upper terminal landing. If no iioor calls are registered for the upper floors of the structure, the second mode of operation expedites the return of the elevator car to the lower terminal landing.

In order to expedite further the return of the elevator car to the lower terminal iioor, the elevator car may be prevented from answering calls for up service registered by passengers waiting at the various floors for elevator service. Since the aforesaid service demand is likely to occur during periods wherein little demand for service may be expected from the intermediate floors, it follows that a second mode of operation provides expedited service for a large number of passengers desiring elevator service from the lower terminal oor without unduly penalizing other demands for elevator service.

en an elevator car is assigned to provide special service, the assignment conveniently may be cancelled and the car reset for the iirst mode of operation as the elevator car returns to the lower terminal floor. If the service demand warrants, the elevator car again may be assigned to provide special service.

If the elevator car is prevented from answering up oor calls registered by passengers awaiting service at the intermediate floors, and if the elevator car stops during up travel at a lioor for which such a call is registered, the call preferably is cancelled or reset. The stopping of the elevator car may be in response to a registered car call for the same floor.

The number of elevator cars in a bank which are assigned to provide special service preferably is dependent on the service demand. For example, if a predeter- 2,699,227 Patented Jan. 11, 1955 f. ICC

mined number of car calls are registered in a first elevator car located at the lower terminal licor, this car alone may be assigned to provide special service. However, if a predetermined number of car calls are registered in a plurality of elevator cars at the same time the entire bank of elevator cars may be assigned to provide the special service. Such special service may continue until the service demand decreases. Conveniently, the system may be reset for the first mode of operation when one of the elevator cars returns to the lower terminal floor.

It is therefore a first object of the invention to provide an improved elevator system having various modes of operation which are selected automatically in accordance with service demand.

It is a second object of the invention to provide an elevator system as defined in the preceding paragraph wherein the transfer of the system from a first to a second mode of operation is dependent on the number of registered car calls for elevator service.

It is a third object of the invention to provide an elevator system as defined in either of the preceding two paragraphs, wherein the number of cars assigned to providedspecialized service is dependent on the service deman It is a fourth object of the invention to provide' an elevator system having iirst and second modes of operation wherein the number of elevator cars transferred from operation in accordance with the first mode to operation in accordance with the second mode is dependent on the number of elevator cars having predetermined quotas of car calls registered.

It is a fifth object of the invention to provide an elevator system as defined in any of the preceding four paragraphs wherein an elevator car assigned to provide specialized service or to provide service in accordance with the second mode of operation is conditioned to reverse at the farthest call for service in the direction of travel of the elevator car.

It is a sixth object of the invention to provide an elevator system as defined in any of the preceding five paragraphs wherein an elevator car which is assigned to provide specialized service or to provide service in accordance with the second mode of operation is prevented from answering registered floor calls in one direction of travel of the elevator car.

It is a seventh object of the invention to provide an elevator system wherein one or more elevator cars may be assigned to provide specialized service and wherein an elevator car assigned to provide specialized service is reset following each trip on which the elevator car is assigned to provide such specialized service.

It is an eighth object of the invention to provide an elevator system wherein an elevator car may be assigned to provide specialized service during which the elevator car is prevented from answering registered oor calls requiring service in a predetermined direction and wherein the stopping of an elevator car while traveling in such direction at a iioor for which such a call is registered results in a resetting of such call for service.

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

Figure l is a schematic view with circuits shown in straight-line form of a portion of an elevator system embodying the invention,

Fig. 2 is a schematic view with circuits shown in straight-line form of a further portion of the elevator systern illustrated in Fig. l,

Fig. 3 is a schematic view with circuits shown in straight-line form of a further portion of the elevator system illustrated in Figs. l and 2, and

Figs. lA, 2A and 3A, respectively, are key representations of relays and switches illustrated in Figs. l, 2 and 3. If Figs. lA, 2A and 3A are horizontally aligned respectively with Figs. 1, 2 and 3, it will be found that corresponding contacts and coils of relays and switches shown in the horizontally aligned figures are substantially in horizontal alignment.

In order to facilitate the orderly presentation of the invention, a number of conventions have been adopted.

Although the invention may be incorporated in an elevator system of any desired number of elevator cars, serving a structure having any desired number of lloors or landings, it will be assumed that the invention is incorporated in an elevator system having three elevator cars serving a structure having six iloors or landings. The elevator cars are designated by the reference supporters A, B and C. lnasmuch as the circuits associated with the three elevator cars are similar, it will sutlice to show primarily the circuits associated with the elevator cars A and B. However certain components associated with the elevator car C also will be referred to.

Because of the similarity of the circuits and components associated with the three elevator cars, components associated with the elevator cars B and C will be identitied by the same reference characters employed for the components associated with the elevator car A preceded by the appropriate letter B or C. For example, the resistors R8, BRS and CRS are associated respectively with the elevator cars A, B and C.

Relays and switches employed for the elevator system may have front or make contacts and back or break contucts. Front or make contacts of a relay are closed when the relay is energized and picked up. The contacts are open when the relay is deenergized and dropped out. Back or break contacts of a relay are closed when the relay is deenergized and dropped out. The back or break contacts are open when the relay is energized and picked up.

Each set of contacts of a relay or switch is designated by the reference characters employed for the relay or switch followed by a suitable numeral specific to the set of contacts. For example, the reference characters U1 and U3 designate the rst and third sets of contacts respecively associated with the up switch U of the elevator car In order to further facilitate the presentation of the invention, certain apparatus specific to car A and certain apparatus common to all of the elevator cars are set forth as follows:

Apparatus for car A E-inductor slowdown relay F-inductor stopping relay V-speed relay L-up switch M-running relay D-down switch G-holding relay W-up preference relay X-down preference relay 70T-noninterference relay DR-door relay HC-high call reversal relay ICR to CR--car call registering relays T-car call stopping relay 78U--call-above relay S-oor call stopping relay 78-ca1l relay Q--quota relay Apparatus common to all cars 1UR to SUR-up iioor call registering relays 2DR to 6DR-down floor call registering relays HCM-bank high call reversal relay TEl-first timing relay TEZ-second timing relay Figure 1 Fig. 1 shows the elevator cars A and B and certain control circuits associated therewith. The elevator car A will be assumed to be stopped at the second iloor of the structure whereas the elevator car B will be assumed to be stopped at the fifth floor of the structure. With these exceptions, the circuits and mechanisms associated with the two elevator cars are similar and will be understood by reference to those associated with the elevator car A.

The elevator car A is connected by a rope or cable to a counterweight 11. The rope 10 passes over a sheave 12, which is secured to a shaft 13 for rotation therewith. The shaft 13 is rotated by a motor 14 which may be of any conventional type. For present purposes it will be assumed that the motor 14 is a direct current motor having its armature 14A secured to the shaft 13 and having a field winding 14F which is permanently connected across two direction current buses L1 and L2 which supply direct current energy for the control circuits.

The elevator car A has therein a plurality of normallyopen car-call push buttons 1c to 6c which are actuated for the purpose of registering calls respectively for the iirst to sixth floors as desired by passengers entering the elevator car.

To permit registration of calls for service by prospective passengers located at the various oors served by the elevator cars, push button stations are located at such oors. Such a station is shown in Fig. l for the third iloor. It includes a normally-open up oor call push button 3U which is pressed by a prospective passenger desiring elevator service in the up direction. A similar push button is located at each floor from which service in the up direction may be desired. The station also includes a normally-open push button 3D which is pressed by a prospective passenger desiring elevator service in the down direction. A similar push button is located at each tloor from which elevator service in the down direction may be desired. The numeral of the reference characters (as 3D or 3U) indicates the floor at which the push button is located.

The elevator car A also has mounted thereon a slowdown inductor relay E and a stopping inductor F which may be of conventional construction. The slowdown relay E has two sets of break contacts E1 and E2 associated therewith. The relay has a normally incomplete magnetic circuit and energization of the winding of the relay alone does not affect the associated contacts. However, if the slowdown relay E reaches an inductor plate UEP located in the hoistway of the elevator car while the winding of the relay is energized, the contacts E1 open. ln Fig. l the inductor plate UEP is assumed to be mounted in the hoistway to be reached by the slowdown relay E as the elevator car A nears the third oor. Il the elevator car A is to stop at the third oor, the winding of the relay E is energized and when the relay reaches the inductor plate UEP for the third door, the contacts E1 open to initiate a slowdown operation for the elevator car. It will be understood that a similar inductor plate is similarly associated with each of the iloors at which the elevator car A may stop during up travel thereof.

During down travel of the elevator car A, the inductor relay E cooperates with down inductor plates DEP to initiate a slowdown of the elevator' car as it approaches a lloor at which the elevator car is intended to stop. For example, if the elevator car is to stop during down travel at the third oor, the winding of the inductor relay E is energized as the elevator car nears the third oor. When the inductor relay reaches the down inductor plate DEP for the third floor, the contacts E2 open to initiate a slowdown operation of the elevator car. lt will be understood that a similar inductor plate DEP is provided for each of the oors at which the elevator car A is to stop during down travel thereof.

The stopping relay F similarly cooperates with inductor plates UFP and DFP for the purpose of bringing the elevator car to a stop as it reaches a oor at which it is to stop. Thus, if the elevator car A during up travel is to stop at the third iloor, the winding of the stopping relay F is energized and as the inductor relay of stopping relay F reaches the stopping inductor plate UFP for the third oor, the contacts F1 open. These contacts in opening result in stopping of the elevator car at the third floor. A similar inductor plate is provided at each of the oors for which the elevator car A is to stop during up travel thereof.

If the elevator car A is to stop at the third lloor during down travel thereof the winding of the stopping relay is energized and as the relay reaches the inductor plate DFP for the third floor, the contacts F2 open to produce a stopping operation of the elevator car at the third oor. It will be understood that a similar inductor plate is provided for each of the oors at which the elevator car A is to stop during down travel thereof.

Because of the large number of control circuits required, it is conventional practice to provide each elevator car with a floor selector 16. This selector includes a plurality of rows of contact segments mounted on the insulating panel 16A. Only two rows of contact segments a1 to a5, d1 to d5 are illustrated in Fig. l. These contact segments are successively engaged during travel of the elevator car respectively by brushes aa and dd for the purpose of controlling the energizations of certain circuits. For example, if the elevator car A during down travel is to stop at the third oor in response to a car call, the brush aa engages the contact a3 shortly before the elevator car A reaches the third iioor, to initiate a stopping operation thereof.

The brushes an and dd are mounted on a brush carriage 16C which is mounted for movement in accordance with movement of the elevator car, but at a greatly reduced rate. In the embodiment of Fig. 1, it is assumed that the carriage 16C has threaded engagement with a screw 16S which is coupled to the shaft 13 through suitable gearing for rotation in accordance with movement of the elevator A. Consequently, as the elevator car A moves, the brushes mounted on the carriage 16C permit the energization of appropriate circuits at various points of travel of the elevator car.

Although the driving motor 14 may be energized in various ways, it will be assumed that the control of this motor is of the type commonly referred to as a variable voltage control. In such a control, a direct current generator 17 has its armature 17A connected in a loop with the armature 14A of the motor. A series field winding 17S for the generator also may be included in this loop. The generator has a main field winding 17F which is connected for energization from the buses L1 and L2 through a reversing switch. This reversing switch includes contacts U2 and U3 of an up switch. When these contacts ar closed, the field winding is energized with proper polarity for up travel of the elevator car. On the other hand, when contacts D2 and D3 of a down switch are closed, the tield winding is energized with proper polarity for down travel of the elevator car. The energization of the field windings is completed through a resistor R1 for slow speed operation of the elevator car or through make contacts V1 of a speed relay for full speed operation of the elevator car.

The elevator car A is provided with a conventional spring-applied electromagnetically-released brake. This brake includes a brake drum 18D which is secured to the shaft 13 for rotation therewith. A brake shoe 18C normally is biased against the brake drum by means of a spring (not shown). The brake is released upon energization of a brake coil 18B which cooperates with a magnetic armature 18A secured to the shoe 18C. The coil 18B is connected to the buses L1 and L2 for energization either through make contacts U1 or through make contacts D1 of the up switch U or the down switch D.

The speed relay V is connected for energization from the buses L1 and L2 through either of two paths. One of these paths includes make contacts U4 of the up switch, a limit switch 19 and the break contacts E1 of the slowdown relay. The limit switch 19 is a camoperated normally-closed switch which is opened as the elevator car nears its upper limit of travel.

The remaining path of energization comprises the make contacts D4 of the down switch, a limit switch 20 and the break contact E2 of the slowdown relay. The limit switch 20 may be cam operated. It is normally closed and is opened as the elevator car A nears its lower limit of travel.

As long as the elevator car A is running, the running relay M is energized. This relay can be energized only as long as the make contacts DR1 of a door relay DR are closed. These contacts are closed only as long as all of the hoistway doors and car doors for the car A are closed. Such safety provisions are well known in the art.

The running relay M initially can be energized only if the break contacts 78-1 are closed to indicate that a call for service has been registered and if the break contacts 70T1 are closed to indicate that sufficient time has elapsed since the last stop of elevator car A to permit discharge or entry of passengers.

Assuming that the foregoing contacts associated with the running relay M are closed, the relay may be energized initially through either of two paths. One of these paths is as follows:

follows that the elevator car will be conditioned for up travel. The limit switch 21 is a normally-closed mechanically-operated switch which is opened as the elevatoll car A nears its upper limit of travel. When energized, the up switch U closes its make contacts U5 to establish a holding circuit around the contacts 70T1, 78-1 and W1.

The second path for initially energizing the running relay M may be traced as follows:

L1, 70T1, 78-1, X1, F2, 22, D, M, DRI, L2

Since the down switch D now is energized, it follows that the elevator car A is conditioned for down travel. The limit switch 22 is a mechanically-operated normallyclosed switch which is opened as the elevator car A nears its lower limit of travel. When it picks up, the down switch D closes its make contacts D5 to establish a holding circuit around the contacts 70T1, 78-1 and X1.

The slowdown relay E, the inductor relay F, and a holding relay G are energized in parallel from the buses L1 and L2 through make contacts M1 of the running relay M. To complete an energizing circuit for these relays E, F and G, one of three conditions must be present. First, the make contacts T1 are closed to indicate that a car call is registered for a floor which the elevator car A is approaching. Second, the contacts HC1 are closed to indicate that the elevator car A is conditioned to reverse at the farthest registered call in the direction of travel of the elevator car, and the make contacts 78U1 are closed to indicate that the farthest call in such direction has been reached. Third, the make contacts S1 are closed to indicate that the elevator car A is conditioned to stop at a floor in answer to a registered floor call for such oor.

When the holding relay G is energized, it closes its make contacts G1 to establish with the make contact M1 a holding circuit for the inductor relays E and F.

The direction of travel of the elevator car A is determined initially by an up preference relay W and a down preference relay X. For the up preference relay W to be energized, the break contacts D6 must be closed (i. e. the down switch D is energized). The break contacts X2 must be closed (i. e. the down preference relay X is deenergized). The limit switch 23 also must be closed. This switch is normally closed and is opened as the elevator car A reaches its upper limit of travel, in this case, the sixth oor.

Energization of the up preference relay W also requires closure of at least one of three sets of contacts. These include the break contacts HC2 which are closed when the elevator car A is not conditioned to reverse at the farthest call in its direction of travel. Break contacts 78U2 are closed as long as a call exists for a floor above the position of the elevator car A. Make contacts M2 are closed as long as the elevator car A is running.

The down preference relay X is energized if the break contacts U6 are closed (i. e. the up switch U is deenergized), the break contacts W2 are closed (i. e. the up preference relay is deenergized) and the limit switch 24 is closed. This limit switch is normally closed and is opened as the elevator car A reaches the lower terminal Hoor.

As long as the elevator car A is running, the make contacts M3 are closed to energize the non-interference relay 70T. When the elevator car A stops, the contacts M3 open to deenergize the relay. However, the relay 70T has a substantial delay in drop out. This delay may be provided in any suitable manner as by connecting a resistor R2 across the relaycoil. The time delay in drop out is selected to be sufficient to permit discharge of passengers from the elevator car A or entry of passengers into the elevator car A after each stop.

It will be recalled that the door relay DR is connected across the buses L1 and L2 through contacts operated by each door associated with the elevator car A. If any of the doors are open, the contacts associated therewith are also open to prevent energization ofthe door relay DR.

Energization of the high call reversal relay HC prepares the elevator car A to reverse during up travel at the farthest registered call for service which the elevator car is conditioned to answer. The high call reversal relay HC may be energized if the elevator car A is conditioned for up travel (break contacts X3 are closed) and if one of two other conditions is satisfied. If the entire bank of elevator cars is conditioned for high call reversal operation, make contacts HCMI of a bank high call reversal relay are closed to complete an energizing circuit for the elevator high call reversal relay HC. Alternatively, if the elevator car A is positioned at the lower terminal floor, the brush yy engages a contact segment y1. It will be understood that the contact segments y1 and the brush yy are positioned respectively on the panel 16A and the brush carriage 16C of the oor selector and are positioned to be in engagement when the elevator car A is at the lower terminal oor. Under these circumstances, if the car A has received its quota of registered car calls, the make contacts Q1 of the quota relay Q are closed to complete an energizing circuit for the high call reversal relay HC. Following its energization, the high call reversal relay HC completes through its make contacts HCS a holding circuit which maintains energization of the relay until the contacts X3 open.

Figure 2 Figure 2 shows the call registration circuits for the elevator cars. Car call registration circuits are illustrated for the elevator cars A and B in the upper part of this figure.

It will be recalled that the elevator car A is provided with a plurality of push buttons 1c to 6c for the purpose of registering car calls, Each of these push buttons has associated therewith a car call registering relay ICR to 6CR respectively. The push buttons and call registration relays cooperate with four rows of contact segments located on the tioor selector for the elevator car A. The contact segments a1 to a5 cooperate with the brush aa for the purpose of initiating a stopping opera tion of the elevator car during down travel of the elevator car respectively at the first to fifth fioors. The contact segments b2 to b6 cooperate with a brush bb for the purpose of initiating a stopping operation of the elevator car during up travel of the elevator car respectively at the second to sixth fioors. A brush cc cooperates with a row of contact segments c2 to c6 and a brush dd cooperates with a row of contact segments d1 to d5 for the purpose of cancelling registered car calls as they are answered respectively during down travel and up travel of the elevator car. lt will be understood that for each contact segment, the numeral of the reference character designates the floor with which the contact segment is associated. Thus, the reference character a1 designates the contact segment for the first floor in the a row.

By reference to Fig. 2, it will be observed that when the car call push button Sc is pressed the car call registering rclay SCR is connected therethrough across the buses L1 and L2. This relay closes its make contacts SCRI to establish a holding circuit around the push button. The Contact segments a and b5 are connected through this set of contacts to the bus L1.

if the elevator car A is set for down travel, the make contacts X4 are closed. And if the elevator car is approaching the fifth fioor, the make contacts M4 of the running relay also are closed. Consequently, as the elevator car nears the fifth fioor, the brush aa engages the Contact segment aS to complete the following circuit for the car call stopping relay T:

L1, SCRI, a5, an, X4, T, M4, L2

The energization of the relay T initiates a stopping operation of the elevator car A at the fifth floor.

As the elevator car A continues its approach toward the fifth floor, the Contact segment c5 is engaged by the brush ce. As the elevator car comes to a stop, the break contacts MS of the running relay close to com plete the following cancelling circuit:

L1, SCRI, SCRN, c5, Cc, X5, M5, L2

The operating coil of the registering relay SCR and the cancelling coil SCRN are wound in opposition on a common core. Consequently, energization of the cancelling coil SCRN cancels the effect of the operating coil and resets the registering relay SCR. Preferably, as the elevator car stops at the fifth floor, the brush aa passes slightly below the associated contact segment aS, however, the brush cc remains in engagement with the associated contact segment c5 as long as the elevator car A remains at the fioor.

Next it will be assumed that the same call is registered for the fifth floor as the elevator car A travels up towards the fifth oor. Under these circumstances, the make contacts W3 and W4 of the up preference relay are closed. As the elevator car A nears the fifth floor, the brush bb engages the contact segment b5 to complete the following circuit:

L1, SCRI, b5, bb, W3, T, M4, L2

The energization of the car call stopping relay T results in the initiation of a stopping operation for the fifth floor.

As the elevator car A continues to approach the fiftli floor, the brush dd engages the contact segment d5 to complete the following circuit:

L1, SCRI, SCRN, d5, dd, W4, M5, L2

The energization of the cancelling coil SCRN resets the call registering relay SCR. During the stopping operation, the brush bb preferably passes slightly above the associated contact segment b5 whereas the brush dd remains in engagement with the associated contact segment d5 as long as the elevator car A is at the fifth floor.

The car call registering circuits for all of the intermediate tloors are similar to those described for the fifth fioor. For this reason and to conserve space, the intermediate floor circuits are illustrated in Fig. 2 only for the second and fifth fioors.

The car call registering circuits for the upper terminal (sixth fioor) may be similar to those employed for the intermediate floors. However, since the elevator car A stops at the sixth floor only during up travel, contact segments for the sixth floor need not be provided in the a and d rows. By reference to Fig. 2 it will be noted that only contact segments b6 and c6 are provided for the sixth floor.

The car call registering circuits for the lower terminal or first floor may be similar to those provided for the intermediate floors. Since the elevator car stops at the first Iioor only during down travel, contact segments for the first floor need not be provided in the b and c rows. For this reason, in the car call registering circuits only contact segments a1 and d1 are illustrated for the first oor.

The central part of Fig. 2 illustrates up lioor call registering circuits. These circuits are operated by means of normally-open push buttons 1U to SU which are located respectively at the first to fifth fioors. The push buttons have associated therewith up fioor call registering relays 1UR to SUR and cancelling coils IURN to SURN in a manner which will be clear from the discussion of the call registering relays and cancelling coils associated with the car call push buttons.

The up fioor call registering relays 1UR to SUR and their cancelling coils are associated with contact segments for each of the elevator cars in the bank. For example, a row of contact segments e1 to e6 is provided for the elevator car A and cooperate with a brush ee. A brush ff cooperates with a row of contact segments f1 to f5, for the elevator car A.

Let it be assumed that while the elevator car A is traveling up a prospective passenger waiting on the fifth floor presses the up floor call push button 5U to energize the up fioor call registering relay SUR. This relay closes its make contact SURI to establish a holding circuit around the push button.

Since the elevator car is assumed to be traveling up, the make contacts W5 of the up preference relay W are closed. It will be assumed further that the break contacts HCS of the high call reversal relay HC are closed. As the elevator car A nears the fifth floor, the brush ee engages the contact segment e5 to complete the following circuit:

L1, 5UR1, e5, ee, W5, HCS, S, L2

The energization of the fioor call stopping relay S initiates the stop at the fifth floor. in response to movement ot' the caitowards the fifth oor, the brpsh ff engages its contact segment f5. As the elevator car stops, the break contacts M6 close to complete the following cancelling circuit:

L1, SURI, SURN, f5, ff, W6, M6, L2

This resets the up floor car registering relay SUR. As the elevator car A comes to a stop, the brush ee preferably passes shghtly above the contact segment e5. However,

the brush ff remains in engagement with the contact segment f as long as the elevator car A remains at the fifth floor. By inspection of Fig. 2, it will be observed that the contact segment e5 is connected to the corresponding contact segments for the other elevator cars in the bank (such as contact segment BeS for the elevator car B). Similarly, the contact segment f5 is connected to corresponding contact segments (such as the contact segment BfS) for the remaining cars of the bank. Consequently, operation of the push button 5U is effective to stop the first up traveling elevator car which reaches the fifth fioor and which is conditioned to accept the call at the fifth floor.

The up floor call registering circuits for all of the intermediate fioors are similar. Consequently, such circuits are illustrated in Fig. 2 only for the second and fifth floors.

During up travel, the elevator cars also stop at the sixth floor if they reach such floor. For this reason, a single contact segment e6 suffices for the sixth fioor and is permanently connected to the bus L1. Since the elevator car A does not stop during up travel at the lower terminal or first floor, a contact segment in the e row is not required. With this exception, the call registering circuits for the first floor are similar to those described for the fifth floor. l

The lower part of Fig. 2 illustrates the down floor call registering circuit for the elevator cars. Down floor calls are registered by operation of normally-open push buttons 2D to 6D which have associated therewith down floor call registering relays 2DR to 6DR and cancelling coils ZDRN to 6DRN. Each push button cooperates with its call registering relay and its cancelling coil in the manner discussed with reference to the up floor call push buttons.

For the elevator car A, a row of contact segments g1 to g5 cooperates with a brush gg and a row of contact segments h2 to h6 cooperates with a brush hh. Let it be assumed that the elevator car A while traveling down is approaching the fifth floor at which a down floor call has been registered by operation of the push button 5D. Such operation results in energzation of the down floor call registering relay 5DR to close the make contacts 5DR1. Since the elevator car is traveling down, the make contacts X6 and X7 are closed.

As the elevator car A nears the fifth floor, the brush gg engages the contact segment g5 to complete the following circuit:

Li, sDRi, gs, gg, X6, s. L2

The energization of the floor call stop relay S initiates a stopping operation of the elevator car A at the fifth floor. As the elevator car continues its approach, a brush hh engages the contact segment h5. The stopping of the elevator car A results in closure of the break contacts M6 to complete the following cancelling circuit:

L1, SDRl, SDRN, h5, hh, X7, M6, L2

The energization of the cancelling coil resets the call registering relay SDR. Preferably, as the elevator car A comes to a stop, the brush gg passes slightly below the associated contact segment g5, but the brush hh remains in engagement with the associated contact segment h5.

The contact segment g5 is connected to corresponding contact segments (such as the contact segment BgS) of the remaining cars. Similarly, the contact segment h5 is connected to the corresponding contact segments (such as the Contact segment BhS) for the remining cars. Consequently, the first elevator car to approach the fifth floor while traveling down will answer a call registered by the call registering relay SDR.

The down floor call registering circuits for all of' the intermediate fioors are similar and may be traced readily in Fig. 2. The down floor call registering relays for the upper terminal or sixth floor also may be similar. However7 since the elevator car A does not stop at the sixth oor during down travel, the contact segment in the g row may be omitted for the sixth floor. Since the elevator car A always stops at the lower terminal floor, a single contact segment gl may be provided for the elevator car A and this contact segment may be permanently connected to the bus L1.

Figure 3 In Fig. 3, a call circuit 30 is provided which has two functions. This circuit energizes a call relay 78 when no call is registered in the elevator by the car call push buttons for the elevator car A or by any floor call push button. In addition, the call circuit 30 energizes the call above relay 78U as the elevator car during up travel nears the highest floor for which a call is registered.

The call-above circuit 30 includes break contacts for all of the floor call registering relays and for all of the elevator A car call registering relays arranged in the order of the floors. This circuit may be traced as follows:

L1, 6DR2, 6CR2, SURZ, SDRZ, 5CR2, 4UR2, 4DR2, 4CR2, 3UR2, 3DR2, 3CR2, ZURZ, ZDRZ, 2CR2, lCRZ, 1UR2, 78, L2

By inspection of this circuit, it will be observed that as long as a call is registered by the car call push buttons for the elevator car A or by the floor call push button the relay 78 is deenergized.

The call circuit 30 has associated therewith a row of contact segments k1 to kS which are engaged successively by the brush kk as the elevator car A moves. The contact segments are so located relative to the call circuit 30 that each contact segment is placed below all break contacts of the call circuit which require travel of the elevator car A above such contact segment. Thus, the contact segment k5 is connected to the call circuit between the contacts SURZ and SDRZ. The contact segment k4 is connected between the contacts 4UR2 and 4DR2. The location of the remaining contact segments similarly may be ascertained by reference to Fig. 3. It will be noted that the relay 78U is connected between the brush kk and the bus L2 through make contacts W7 of the up preference relay W.

In certain cases, it is desirable to prevent registered calls from affecting the call circuit 30. For example, it may be desirable under some conditions to prevent registered up fioor calls from affecting the operation of the relay 78U and 7S. To this end, make contacts of the high call reversal relay HC are provided for the purpose of shunting the break contacts of the up floor call relays. When the relay HC is energized, the contacts HC4 to HC7 close to shunt respectively the contacts SURZ to 2UR2 respectively.

The quota relay Q indicates the presence of a predetermined service demand. As shown in Fig. 3, the quota relay preferably is energized in accordance with the number of registered car calls. Energization of the relay Q takes place only while the elevator car A is conditioned for up travel (make contacts W8 are closed). The energization of the relay Q is dependent on the condition of a parallel circuit having five parallel arms. Each arm contains a suitable resistor and a set of make contacts of a separate one of the car call registering relays for the elevator car A. The resistors are so proportioned that a predetermined number of car calls must be rigstered before the relay Q will pick up. For example, it will be assumed that at least three car calls must be registered to provide sufficient current for the relay Q to pick up. When the relay Q picks up, it closes make contact Q3 to establish a holding circuit which maintains the energization of the relay until the contacts W8 open.

Operation of the relay Q is employed under certain conditions to provide specialized service by the elevator car A. Under certain circumstances, it may be desirable to provide specialized service from the entire bank. Such service is provided by the bank high call reversal relay HCM, which is energized through a parallel circuit having one arm for each of the elevator cars of the bank. Thus, one of the parallel arms includes a resistor R8 and make contacts Q4 of the quota relay Q. A second arm includes a resistor BRS and corresponding make contacts BQ4 of the quota relay for the elevator car B. A third arm contains a resistor CRS and make contacts CQ4 of the quota relay for the car C. Upon picking up, the relay HCM closes make contacts HCM3 which with make contacts TBI-2 of a timing relay establish a holding circuit around the parallel arms.

The relay HCM when energized is maintained in a picked up condition for a minimum time determined by timing relays TEl and TE2. These relays have time delays in drop out provided in any suitable manner, as by resistors R9 and R10 connected across the relay coils.

As long as the relay HCM is energized and picked up, the timing relays cooperate to open the contacts TEl-Z briefly at timed intervals. If the energization of the relay 11 HCM through the resistors R8, BR@ and CRS is insufcient to maintain the relay HCM picked up during one of the brief openings of the contacts TEl-Z the relay HCM drops out.

Operation In order to assure a full understanding of the invention, certain typical operations of the elevator system now will be considered. First, it will be assumed that the elevator cars are parked at the lower terminal tloor and that a passenger enters the elevator car A at the lower terminal oor for the purpose of proceeding to the fth tloor.

The doors of the elevator cars may be of the manuallyopened spring-closed type F or may be of conventional power-operated design. Upon entering the elevator car A, the passenger presses the car call push button c (Fig. 2) to energize the associated car call registering relay SCR. This relay closes its make contacts 5CR1 to establish a holding circuit around the push button. The relay also opens its break contacts 5Cl` 2 (Fig. 3) to deenergize the relays 78U and 7S. inasmuch as the elevator car A is at the lower terminal floor, it will be understood that the up preference relay W is energized and picked up.

The car call registering relay also closes its make contact SCRS. However, it will be recalled that the energization of the relay Q through a single one of the resistors R3 to R7 is insutiicient to pick up the relay.

Inasmuch as the relay 78 is now dropped out, the contacts 78-1 (Fig. l) are closed. lt will be assumed also that the elevator cai' A has remained at the lower terminal iloor for a time suiiicient to result in closure of the break contacts 70T1. Consequently, upon closure of the doors. the door relay DR closes its make contacts DRI to com plete the following circuit:

L1, 70T1, 78-1, W1, F1, 21, U, M, DRI, L2

Upon energization, the up switch U closes its make contacts U1 to release the elevator brake. Contacts U2 and U3 close to energize the generator eld winding 17F with proper polarity for up travel of the elevator car. Contacts U4 close to complete the following energizing circuit for the speed relay V:

L1, U4, 19, Ell, V, L2

The speed relay closes its make contact V1 to shunt the resistor R1 and conditions the elevator car for full speed operation.

Continuing with the operation of the up switch U, the energized up switch closes its make contacts U5 to establish a holding circuit around the contacts 7tlT1, 78-1. and W1. Break contacts U6 open to prevent energization therethrough of the down preference relay X.

The elevator car A now accelerates in the up direction for the puipose of carrying the passenger to the tifth oor.

It will be recalled that the running relay M also was energized. As a result of its energization, the running relay closes its make contacts to prepare the relays G, E and F for subsequent energization. The make contacts M2 close to maintain the energization of the up preference relay despite subsequent opening of the break contacts HCZ and 78U2. Make contacts M3 close to energize the non-interference relay 70T. The non-interference relay opens its break contacts 70T but such opening has no immediate effect on the operation of the system.

Referring to Fig. 2, the ruiming relay M closes its make contacts M4 and opens its break contacts M5 and M6. Such contact operations have no immediate effect on the operation of the system.

As the elevator car nears the fifth floor, the brush kk engages the contact segment kS which is positioned above the break contacts SDRZ. Consequently, the call-above relay 7 8U is energized through the circuit The relay 'ISU closes its make contacts 78U1 (Fig. l), and opens its break contacts 78U2. However, inasmuch as the make contacts HC1 under the assumed conditions are open, and contacts HG2 and MZ are closed, the energization of the relay 78U has no immediate effect on the operation of the system.

However, the approach ot the elevator car A towards the fifth iloor brings the brush bb (Fig. 2) into engagement with the Contact segment b5 to energize the car call stopping relay T through the circuit L1, 5CR1, B5, bb, W3, T, M4, L2

The car call stopping relay closes its make contacts T (Fig. l) to energize through the contact M1 the three relays G, E and F in parallel. The relay G closes its make contacts G1 to establish a holding circuit around the contacts T1.

The energization of the inductor slow down and stopping relays E and F prepares these relays for subsequent operation. As the elevator car A nears the tifth tloor, the inductor slow down relay E reaches the inductor plate UEP for the fifth floor which completes a magnetic circuit resulting in the opening of the normally-closed contacts El. Such opening deenergizes the speed relay V. As a result of the deenergization of the speed relay V, make contacts V1 open to introduce the resistor R1 in series with the generator field winding 17F. The resulting decrease in the output of the generator slows the elevator car A to a landing speed.

As the elevator car A slowly approaches the fifth iloor, the stopping relay F reaches the inductor plate UF l tor the fifth floor. This completes a magnedc circuit v-/liich results in opening of the normali-closed contacts Fl. ln opening the contacts F1 deencrgize the up switch U and the running relay M.

The up switch U now opens its make contacts Ul to apply the elevator brake. Contacts U2 and U3 open to deenergize the generator field winding and the elevator car now stops accurately at the fifth looi. Opening of the make contacts U4 and U5 and closure of the break contacts U6 have no immediate cilect on the operation of the system.

The ruiming relay M opens its make contacts Ml to deenergize the relays G, E and F. The relay G opens its make contacts G1. Opening of the make contacts M2 has no immediate effect on the system operation. Make contacts M3 open to deenergize the non-interference relay 70T. This relay now starts to time out.

Referring to Fig. 2, it should be noted that as the elevator car A continues its approach toward the fifth oor, the brush dd engages the contact segment d5. When the running relay drops out to close its break contacts M5, the following cancelling circuit is completed:

L1, SCRl, SCRN, d5, dd, W4, M5, L2

Consequently, the car call registering relay SCR is reset. As the car cornes to a stop, the brush bb passes slightly above the associated contact segment b5.

The resetting of the call registering relay SCR opens the make contacts SCRL In addition, the break contacts SCRZ (Fig. 3) reclose to complete an encrgizing circuit for the call relay 78 (Fig. 3). The make contacts SCRS open to interrupt the partial energiz/.ation oi" the quota relay Q.

The call relay 78 as a result of its energization opens its break contacts 78-1 (Fig. l). Consequently, when the non-interference relay 70T times out and recloses its break contacts 70T1, the up switch U and the running relay M can not be energized until a call is registered from one of the floors or in the elevator car A to close the Contact 7 8-1.

Next it will be assumed that as the elevator car A was leaving the first oor in the preceding example, a prospective passenger at the second floor registered an up oor call by operation of the up floor call push button 2U (Fig. 2). Such operation energizes the up floor call registering relay ZUR which closes its contact ZUR to establish a holding circuit around the push button. in addition, the registering relay opens its break contacts ZURZ in the call circuit 30 (Fig. 3) and similar contacts, such as the contact 2UR3, in the call circuits for the remaining elevator cars in the bank. Since the registration of the car call for the tifth oor in the elevator car A has deenergized the

relays

78U and 78, opening of the contacts 2UR2 has no effect thereon. However, the opening of the contacts may affect the remaining elevator cars of the system. For example, the opening of the break contacts 2UR3 deenergzes the relay 78 for the Car B and permits operation of such elevator car.

As the elevator car A nears the second tloor, the brush ee engages the contact segment e2 to establish the circuit L1, 2UR1, e2, ee, W5, HCS, S, L2

The resultant energization of the floor call stopping relay S results in closure of the make contacts S1 (Fig. l) to energize the relays G, E and F. These cooperate to stop the elevator car A at the second floor by a sequence which will be clear from the preceding discussion of the stopping of the elevator car at the fth tloor. As the elevator car stops, the engagement of the brush j? with the contact segment f2 and the closure of the break contacts M6 completes the following cancelling circuit:

This resets the up floor call registering relay ZUR in the manner previously described. As a result of this resetting, the relay opens its contacts 2UR1 and recloses its break contacts ZURZ (Fig. 3). inasmuch as the contacts SCRZ remain open, the reclosure of the contacts ZURZ has no immediate effect on the system. However, the relay also recloses its break contacts 2UR3. If no other call is registered affecting the elevator car B, the reclosure of the contacts 2UR3 results in energization of the call relay B78.

Next it will be assumed that a prospective passenger at the fourth oor registers a down iloor call by operation of the push button 4D (Fig. 2) after the elevator car A reached the fth oor. The resultant energization of the down oor registering relay 4DR closes the make contacts 4DR1 to establish a holding circuit around the push button. In addition, the registering relay opens its break contacts 4DR2 (Fig. 3) and similar contacts for the remaining cars, such as the contacts 4DR3 for the elevator car B. The opening of the break contacts 4DR2 deenergizes the call relay 78. This relay recloses its break contacts 78-1. It will be assumed that the elevator car A has remained at the fifth floor for time sutlicient to permit reelosure of the break contacts 70T1 of the noninterference relay. Consequently, the up switch U and the running relay M are energized in the manner previously described to move the car upwardly to the upper terminal floor. As the elevator car A nears the upper terminal oor, the brush ee (Fig. 2) engages the segment e6 to complete the following energizing circuit:

L1, e6, ee, W5, HCB, S, L2

The relay S closes its make contacts S1 (Fig. 1) to energize the relays G, E and F. These relays initiate a stopping operation of the elevator car A at the sixth oor in a manner which will be clear from the earlier discussion of the stopping of the elevator car at the fifth floor. As it reaches the sixth floor, the elevator car A opens its limit switch 23 (Fig. l) to deenergize the up preference relay W. Since this relay closes its break con- L1, 70T1, 78-1, X1, F2, 22, D, M, DRI, L2

The relay D upon energization closes its make contact D1 to release the elevator brake. Contacts D2 and D3 close to energize the generator eld with proper polarity for down travel. Contacts D4 close to complete through the limit switch 20 and the contacts E2, an energizing circuit for the speed relay V. This relay closes its make contacts V1 to shunt the resistor R1. The elevator car A now accelerates to its full speed in the down direction.

Closure of the make contacts DS establishes a holding circuit around the contacts 70T1, 78-1, and X1. Opening of the break contacts D6 has no immediate effect on the operation of the system. The running relay M upon energization operates its contacts in the manner previously described.

As the elevator car A nears the fourth floor, the brush gg engages the contact segment g4 (Fig. 2) to complete the following energizing circuit:

L1, 4DR1, g4, gg, X6, S, L2

As a result of its energization, the floor call stopping relay S closes its make contact to energize the relays G, E and F. The relay G closes its make contact to establish a holding circuit around the contacts S1. The continued movement of the elevator car A brings the inductor slow down relay adjacent the plate DEP for the fourth oor and completes a magnetic circuit resulting in opening of the contacts E2. Such opening results in deenergization of the speed relay V and this relay opens its make contact V1 to introduce the resistor R1 in series with the generator eld winding. The decrease in energization of the eld winding slows the elevator car to a landing speed. The continued movement of the elevator car A at a slow speed brings the inductor stopping relay F adjacent the inductor plate DFP to open the contacts F2. Such opening deenergizes the down switch D and the running relay M. The down switch D opens its make contacts D1 to apply the elevator brake. Contacts D2 and D3 open to deenergize the generator eld winding and the elevator car stops accurately at the fourth iloor. Opening of make contacts D4 and DS and closure of break contacts D6 have no immediate effect on the operation of the system.

During the stopping operation the brush lzh (Fig. 2) engages the contact segment h4 to complete the following cancelling circuit:

In resetting, the relay 4DR opens its holding contacts 4DR1. In addition, the relay recloses its break contact 4DR2 (Fig. 3) and corresponding contacts in the call circuits for the remaining elevator cars of the bank. If no other call is registered affecting the call circuit 30, the call relay 78 is energized and prevents further operation of the elevator car A.

It will be assumed that the passengerat the fourth oor enters the elevator car and operates the push button 1c (Fig. 2) to initiate movement of the elevator car to the rst floor. The resultant energization of the car call registering relay ICR closes the holding contacts lCRl and opens the break contacts 1CR2 (Fig. 3). Opening of the contacts 1CR2 deenergizes the call relay 78 and this relay closes its break contacts 78-1 (Fig. 1) to permit further movement of the elevator car. If su'icient time has elapsed for the non-interference relay T to drop out, the break contacts 70T1 close. If the doors also are closed, an energizing circuit again is completed for the down switch D and the running relay M. These cooperate in the manner previously discussed to move the elevator towards the first oor.

As the elevator car A nears the rst floor, the brush aa (Fig. 2) engages the contact segment a1 to comple-te an energizing circuit for the car call stopping relay T. This relay closes its make contacts T1 to energize the relays G, E and F through the contacts M1. The energized relays E and F cooperate in the manner previously described to stop the elevator car A at the first oor. As the elevator car stops, the brush dd engages the contact segment d1 to complete the following cancelling circuit:

L1, 1CR1, ICRN, d1, dd, W4, M5, L2

ln resetting, the relay lCR opens its holding contacts 1CR1, and closes its break contacts 1CR2 (Fig. 3) to complete an energizing circuit for the call relay 78. The relay 78 opens its break contacts 781 (Fig. l) to prevent further operation of the elevator car A until a call is registered requiring such ope-ration.

As it reaches the lower terminal floor, the elevato-r car A opens the limit switch 24 to deenergize the down preference relay. This relay closes its break contacts X2 to complete an energizing circuit for the up preference relay W as the elevator ear stops at the lower termin-al floor. The deenergization of the down preference relay X and the energization of the up preference relay W condition the elevator car A for up travel.

It now will be assumed that all of the elevator cars are parked at the lower term-inal floor when passengers entering the elevator car A register car calls for the second, third and fourth oors. Such registration results in opening of the break contacts 2CR2, SCR?. and 4CR2 (Fig. 3). In addition, make contacts 2CR3, 3CR3 and 4CR3 close to energize the quota relay Q. It is assumed in this example that the resistors R3 to R7 are so dimensioned that currents flowing through at least three resistors 4are required to energize the quota relay S suiiciently to pick up.

The registration of a large number of car calls indicates the presence of a substantially high service demand in the up direction from the lower terminal floor. Inasmuch as each stop of the elevator car requires substantial time, it follows that the stopping of the elevator car A a number of times as required by a large number of registered car calls appreciably slows the elevator car.

The registration of a large number of car calls at the lower terminal floor may occur, for example, during an up peak such as the start of a business day in an oice building served by the elevator system. For this reason, it is desirable to expedite the return of the elevator car to the lower terminal floor.

When the relay Q is energized sufficiently to pick up, it closes its make contacts Q3 to establish a holding circuit which maintains the energization of the relay until the make contacts W8 open. These contacts W8 open when the elevator car A reverses to return to the lower terminal floor.

Referring to Fig. 1, it will be noted that energization and pick up of the quota relay Q results in closure of the make contacts Q1. Inasmuch as the elevator car A is positioned at the lower terminal floor, the brush yy is in engagement with the contact segment y1. The break contacts X3 are closed for the reason that the elevator car A is conditioned for up travel. Thus, the following energizing circuit is established for the high call reversal relay HC:

In picking up, the high call reversal relay HC closes its make contacts HC3 to establish a self holding circuit which is interrupted only when the elevator car A reverses to return to the lower terminal floor thereby opening the break contact-s X3.

Energization of the high call reversal relay HC also closes make contacts HC1 to prepare the relays G, E and F for energization when the contacts 7 8U1 close. It will be recalled that these conta-cts close as the elevator car A nears the farthest call during up travel which the elevator car is conditioned to answer. Such reversal tends to expedite the return of the elevator car to the lower terminal floor.

yIf desired, the return of the elevator car further may be expedited by preventing the elevator car A from answering certain registered floor calls during its travel. For example, during the morning up peak, few up calls generally are registered by operations of the up floor call push buttons. For this reason, it is permissible in many cases to expedite the return of the elevator cars to the lower terminal floor by preventing one or more of the elevator cars from answering registered up floor calls during up travel thereof. To this end, the break contacts HCS (Fig. 2) of the high call reversal relay HC open when this relay is energized to prevent energization of the floor call stopping relay during up travel of the elevator car A. (The break contacts HCS may be replaced by break contacts of the quota relay Q, but the break contacts HCS are preferred.)

lf the elevator car A is to ignore up floor calls during up travel, it is desirable that the break contacts of the up oor call relays in the call circuit 30 be shunted during such travel of the elevator car. To this end, the make contacts HC4 to HC7 of the high call reversal relay HC shunt the break contacts of the up oor call relays in the call circuit 30.

The quota relay also closes its make contacts Q4. However, the resistors R8, BR8 and CRS are so propor tioned that the energization of the high call reversal relay through a single resistor is insufficient to pick up the relay.

The elevator car A proceeds upwardly in the manner previously described -answering the registered car calls for the second, third and fourth floors. As the elevator car nears the fourth oor, the brush kk (Fig. 3) engages the contact segment k4 to complete the following energizing circuit for the callabove relay 78U:

As a result of its energization, the call-above relay closes its make contacts 78U1 (Fig. 1) to complete with the contacts HC1 and M1 an energizing circuit f-or the relays G, E and F. Under the assumed conditions, these relays lalso would have been energized in the manner previously described as the elevator car A answered the registered car call for the fourth floor.

16 1In addition, the call-above relay opens its break com tact 7 8U2. It will be recalled that the break contacts HCZ of the high call reversal relay are open. inasmuch as the make contacts MZ of the running relay open as the car comes to a stop, it follows that the up preference relay W is deenergized as the elevator car stops at the fourth floor. The deenergized up preference relay closes its break contacts W2 to complete an energizing circuit for the relay X. Since the down preference relay now is energized and the up preference relay W is deenergized the elevator car A is conditioned to return to the lower terminal floor. The operation of the system in returning the elevator car A to the lower terminal floor will be understood from the foregoing discussion. By reversing the elevator car A at the intermediate Hoor, the return of the elevator car to the lower terminal floor is materially expedited.

Let it be assumed next that for the example just discussed wherein car calls were registered for the second, third and fourth floors in the elevator car, a down floor call also is registered for the fifth oor. it will be recalled that the registration of the down floor call for the fifth oor results in opening of the break contacts SDRZ in the call circuit 30 (and of similar break contacts in the other call circuits). Consequently, the callabove relay 78U cannot be energized until the brush kk reaches the contact segment k5.

After the elevator car has answered the registered car calls for the second, third and fourth floors, it must continue to proceed upwardly until the brush kk engages the contact segment k5 to complete an energizing circuit for the call-above relay 78U. This circuit may be traced as follows:

L1, 6DR2, 6CR2, 5UR3 or HC4, kS, kk, W7, 78U, LZ

The energization of the callabove relay results in closure of the make contacts 78U1 (Fig. l) to establish with the closed contacts HC1 and M1 an energizing circuit for the relays G, E and F. These operate in the manner previously discussed to stop the elevator car A at the fifth oor. It should be noted that the elevator car While traveling up is stopped at the fifth floor in response to a down floor call. This down floor call is the farthest call in the direction of travel of the elevator car which the car is conditioned to answer.

The relay 78U also opens its make contacts 78U2. Inasmuch as the break contacts HCZ are open under the assumed conditions and inasmuch as the make contacts YM2 open as the car stops, it follows that the up preference relay W is deenergized at the fifth floor. Deenergization of the up preference relay is accompanied by closure of the break contacts W2 to complete an energizing circuit for the down preference relay X. Since the up preference relay is deenergized and the down preference relay X is energized, the elevator car A now is conditioned to return to the lower terminal floor. The operation of the system in returning the elevator car A to the lower terminal floor will be understood from the foregoing discussion.

As a further example, it will be assumed that car calls for the second, third, and fourth oors are registered in the car A and car calls for the third, fourth and fifth iloors are registered in the elevator car B. Under these circumstances the quota relays Q and BQ (Fig. 3) both are en ergized sufficiently to pick up. The make contacts Q4 and BQ4 both are closed and it will be assumed that the currents flowing through the two resistors R3 and BRS are sufficient to energize the bank high call reversal relay HCM sufficiently to cause this relay to pick up. Pick up of the relay HCM results in energization of the high call reversal relays for all of the elevator cars in the banks which are conditioned for up travel. For example, the high call reversal relay for the car A is energized through the circuit L1, HC, X3, HCM1, L2

It should be noted that such energization takes place regardless of the position of the elevator car A. That is, it need not be at the lower terminal floor. The relay HC remains energized until the elevator car A reverses to Open the break contacts X3. Since the operation of the elevator cars under the control of the high call reversal relays has been set forth above, further discussion of such operation is believed to be unnecessary.

When the relay HCM picks up it closes its contacts 17 HCM3 (Fig. 1) to energize the high call reversal relay HC through the break contacts X3. The high call reversal relay for each of the remaining cars in the bank similarly is energized.

By reference to Fig. 3 it will be noted that the relay HCM, when picked up, closes its make contacts HCM3 and HCM4. Closure of the contacts HCM4 completes with the break contacts TE2-1 an energizing circuit for the first timing relay 'FE1 which picks up to close its make contacts TBI-1 and TBI-2.

In closing, the contacts TEl-Z of the first timing relay complete with the contacts HCM3 a holding circuit for the bank high call reversal relay HCM. The closed contacts TE1-1 connect the second timing relay TE2 for energization.

Upon being energized, the second timing relay TEZ opens its break contacts TEZ-l to deenergize the rst timing relay TEL-1 and the latter relay starts to time out. After the expiration of the time delay for which it is designed, the first timing relay drops out to open its make contacts TEl-l and TBI-2.

If the energization of the bank high call reversal relay HCM through the resistors R8, BRS and CR8 is insufficient to maintain the relay picked up during the open period of the contacts TE1-2, the relay HCM drops out. In dropping out the relay opens its make contacts HCMS to prevent establishment of the holding circuit therethrough, and opens make contacts HCM4 to prevent energization therethrough of the first timing relay TEL Inasmuch as the drop out of the first timing relay TE resulted in opening of the contacts TEl-l, the second timing relay TEZ started to time out. Upon expiration of its delay in drop out the relay TE2 recloses its break contacts TEZ-l to permit energization therethrough of the first timing relay. If the bank high call reversal relay HCM has dropped out prior to reclosure of the contacts TE2-1 the contacts HCM4 are open and the first timing relay cannot be energized.

Let it be assumed that a sutiicient number of the quota relays remain picked up to maintain the bank high call reversal relay HCM picked'up until the contacts TEZ-l reclose. Such reclosure then reenergizes the first timing relay which recloses its contacts TE1-2 to complete with the contacts HCM3 the holding circuit for the relay HCM. In addition, the contacts TEl-l close to start a new timing cycle. Consequently, the contacts TBI-2 are periodically opened until the energization of the bank high call reversal relay HCM through the resistors R8, BRS and CRS, while the contacts TE1-2 are open, is insuli'icient to maintain the relay in its picked up condition.

From the foregoing discussion, it is clear that when the system is placed on bank high call reversal operation it remains on such operation for at least a predetermined time interval.

The number of the contacts Q4, BQ4, etc. which must be closed to pick up the relay HCM and the number which must be closed to prevent drop out of the relay may be selected as desired. Thus, the design may be such that all of the contacts must be open to permit drop out. As a further example, one less than the number of sets required for pick up may permit drop out of the relay HCM.

Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications falling within the spirit and scope of the invention are possible.

I claim as my invention:

l. In an elevator system, a structure having landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at said landings, said control means comprising conditioning means substantially responsive to the time required for the elevator car to make a trip in a first direction of travel for effecting an operation upon occurrence of a substantial value of said required time, and modifying means responsive to operation of the conditioning means while the elevator car is set for travel in the first direction for expediting reversal of the direction of travel of the elevator car.

2. In an elevator system a structure having landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at said landings, said control means comprising conditioning means substantially responsive to the time required for the elevator car to make a trip in a first direction of travel for effecting an operation upon occurrence of a substantial value of said required time, and modifying means responsive to the conditioning means during travel of the elevator car in the first direction for eXpediting elevator service in a second direction of travel of the elevator car.

3. In an elevator system a structure having landings including terminal landings and intermediate landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car between the terminal landings and to stop the elevator car at said landings in a predetermined service pattern, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car to stop the elevator car at such landings, and modifying means responsive to a predetermined service demand registered by the car call means for modifying the operation of the elevator car from said predeterminedl service pattern at one of the intermediate landings.

4. In an elevator system a structure having landings including terminal landings and intermediate landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the -elevator car at said landings in a predetermined service pattern, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car. and modifying means responsive to a function of the calls registered by the car call means for altering the operation of the elevator car from said service pattern by expediting reversal of the direction of travel of the elevator car at one of the intermediate landings.

5. In an elevator system, a structure having terminal and intermediate landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car between the terminal landings and to stop the elevator car at the landings for which calls are registered, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car, and modifying means responsive to the number of car calls registered to be answered during a trip of the elevator towards a first one of the terminal landings for reversing the direction of travel of the elevator car short of the last-named terminal landing provided that no calls are registered by the car call means requiring further travel of the elevator car towards the last-named terminal landing.

6. In an elevator system, a structure having terminal and intermediate landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car between the terminal landings and to stop the elevator car at the landings for which calls are registered, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car, landing call means operable from each of a plurality of the landings for registering calls from passengers located at the landings and desiring transportation away from such landings, and modifying means responsive to the number of car calls registered to be answered during a trip of the elevator towards a first one of the terminal landings for reversing the direction of travel of the elevator car at the farthest registered call for service during such trip.

7. In an elevator system, a structure having landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at said landings for which calls are registered, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car, landing7 call means operable from each of a plurality of the landings to register calls from passengers at such landings desiring transportation, and modifying means responsive to a function of the calls registered by the car call means for preventing said elevator car from stopping at landings for which calls are registered by the landing call means but for which calls are not registered by the car call means.

8. In an elevator system, a structure having landings to be served by an elevator car, an elevator car, means mounting the elevator car for movement relative to the structure to serve the landings, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at the landings for which calls are registered, said control means comprising car call means operable for registering calls for landings desired by passengers entering the elevator car, landing call means operable from each of a plurality of the landings to register calls from passengers at such landings desiring transportation, and modifying means responsive to a function of the calls registered by the car call means for preventing said elevator car from stopping at landings for which calls are registered by the landing call means but for which calls are not registered by the car call means, and reversal control means responsive to operation of the modifying means for expediting reversal of the direction of travel of the elevator car when all calls which the elevator car is conditioned to answer are answered prior to arrival of the elevator car at a terminal landing.

9. In an elevator system, a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement relative to the structure, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at landings for which calls are registered, said control means comprising car call registering means for registering calls for landing desired by passengers entering the elevator car, landing up-call registering means operable from each of a plurality of the landings by prospective passengers to register calls for service in the up direction, landing down-call registering means operable from each of a plurality of the landings to register calls for service in the down direction, conditioning means responsive to registration of a predetermined number of car calls while the elevator car is adjacent the lower terminal landing, and modifying means responsive to operation of the conditioning means for modifying the operation of the elevator car.

10. In an elevator system, a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement relative to the structure, motive means for moving the elevator car relative to the srtucture, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at landings for which calls are registered, said control means comprising car call registering means for registering calls for landings desired by passengers entering the elevator car, landing up-call registering means operable from each of a plurality of the landings by prospective passengers to register calls for service in the up direction, landing down-call registering means operable from each of a plurality of the landings to register calls for service in the down direction, conditioning means responsive to registration of a predetermined number of car calls while the elevator car is adjacent the lower terminal landing, and modifying means responsive to operation of the conditioning means for reversing the elevator car substantially at the farthest call for service in the up direction.

l1. In an elevator system, a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement relative to the structure, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at landings for which calls are registered, said control means comprising car call registering means for registering calls for landing desired by passengers entering the elevator car, landing up-call registering means operable from each of a plurality of the landings by prospective passengers to register calls for service in the up direction, landing down-call registering means operable from each of a plurality of the landings to register calls for service in the down direction, conditioning means responsive to registration of a predetermined number of car calls while the elevator car is adjacent the lower terminal landing, and modifying means responsive to operation of the conditioning means for preventing response of the elevator car to a call registered by the landing up call registering means.

12. In an elevator system, a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement relative to the structure, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at landings for which calls are registered, said control means comprising car call registering means for registering calls for landing desired by passengers entering the elevator car, landing up-call registering means operable from each of a plurality of the landings by prospective passengers to register calls for service in the up direction, landing down-call registering means operable from each of a plurality of the landings to register calls for service in the down direction, conditioning means responsive to registration of a predetermined number of car calls while the elevator car is adjacent the lower terminal landing, and modifying means responsive to operation of the conditioning means for preventing response of the elevator car to a call registered by the landing up call registering means, said modifying means also operating to reverse the elevator substantially at the farthest call for service in the up direction which the elevator car is conditioned to answer.

13. In an elevator system, a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, an elevator car, means mounting the elevator car for movement relative to the structure, motive means for moving the elevator car relative to the structure, and control means operable in cooperation with the motive means to move the elevator car and to stop the elevator car at landings for which calls are registered, said control means comprising car call registering means for registering calls for landing desired by passengers entering the elevator car, landing up-call registering means operable from each of a plurality of the landings by prospective passengers to register calls for service in the up direction, landing down-call registering means operable from each of a plurality of the landings to register calls for service in the down direction, conditioning means responsive to registration of a predetermined number of car calls while the elevator car is adjacent the lower terminal landing, modifying means responsive to operation of the conditioning means for preventing response of the elevator car to a call registered by the landing up call registering means, and call resetting means responsive to the stopping of the elevator car during up travel at a landing having an operated up-call registering means while said modifying means prevents response of the elevator car to such operated up-call registering means for resetting the up-call registering means.

14. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing first-call registering means operable from each of a plurality of r the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the lan dings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or ear calls are registered, conditioning means responsive to a predetermined registration of a plurality of car calls, and modifying means responsive to operation of the conditioning means for modifying the operation of a plurality of the elevator cars.

15. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, conditioning means responsive to a predetermined registration of a plurality of car calls, and modifying means responsive to operation of the conditioning means for reversing the elevator cars during travel in the first direction substantially at the farthest call for service in the first direction which the elevator cars are conditioned to answer.

16. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, conditioning means responsive to a predetermined registration of a plurality of ear calls, and modifying means responsive to operation of the conditioning means for preventing the elevator cars from answering calls registered by said first-call registering means.

17. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing first-call registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings,

and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first call or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, conditioning means responsive to a predetermined registration of a plurality of car calls, and modifying means responsive to operation of the conditioning means for preventing the elevator cars from answering calls registered by said first-call registering means, said modifying means in operation being effective for reversing each of the elevator cars during travel in the first direction substantially at the farthest call for service in the first direction which each of the elevator cars is conditioned to answer.

18. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing rstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, conditioning means responsive to a predetermined registration of a plurality of car calls, and modifying means responsive to operation of the conditioning means for preventing the elevator cars from answering calls registered by said first-call registering means, and resetting means responsive to the stopping of any of the elevator cars during travel in the first direction at a landing for which a call is registered by the landing firstcall registering means while the elevator cars are prevented from answering said call for resetting the call registered by the last-named registering means.

19. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with control means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car- Calls are registered, conditioning means responsive to a predetermined registration of a plurality of car calls, and controlling means responsive to a predetermined first registration of car calls for modifying the operation of a first one of the elevator cars, said controlling means including means responsive to a predetermined second registration of car calls for modifying the operation of a plurality of said elevator cars.

20. A system as claimed in claim 19 wherein the controlling means is reset for each of the elevator cars after each predetermined operation of each of the elevator cars subject thereto.

2l. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with control means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls o1' car calls are registered, controlling means responsive to a predetermined first registration of calls for conditioning a first number of the elevator cars to reverse at the farthest registered call for service in the first direction which each of the first number of the elevator cars is conditioned to accept, said controlling means including means responsive to a predetermined second registration of calls for conditioning each of a plurality of the elevator cars greater than said first number to reverse at the farthest call for service in the first direction which each of the last-named elevator cars is conditioned to accept.

22. A system as claimed in claim 2l wherein the controlling means for each of said reversals of one of the elevator cars is reset 'for each of the reversed cars.

23. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with control means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, controlling means responsive to a predetermined first registration of calls in a first one of the elevator cars for conditioning a first number of the elevator cars to reverse at the farthest registered call for service in the first direction which each of the first number of the elevator cars is conditioned to accept, said controlling means responsive to a predetermined second registration of calls in a plurality of the elevator cars for conditioning each of a plurality of the elevator cars greater than said first number to reverse at the farthest call for service in the rst direction which each of the last-named elevator cars is conditioned to accept.

24. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing rstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with control means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, controlling means responsive to a predetermined first registration of calls for preventing a first number of the elevator cars from answering calls registered by the first call registering means, said controlling means comprising means responsive to a second predetermined registration of calls for preventing a plurality of the elevator cars greater than the first number from answering calls registered by the first call registering means.

25. A system as claimed in claim 24 wherein the controlling means is reset for each of the elevator cars prevented from answering calls registered by the first call registering means following each trip of such elevator cars in the first direction.

26. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing firstcall registering means operable from each of a plurality of the landings for registering calls for service in a first direction desired by prospective passengers at the landings and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with control means operable in cooperation with the vmotive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, control means responsive to a predetermined first registration of calls for preventing a first number of the elevator cars from answering calls registered by the first call registering means, and for conditioning the first number of the elevator cars for reversal at the farthest registered call in the first direction which each of the first number of the elevator cars is conditioned to answer, said controlling means comprising means responsive to a second predetermined registration of calls for preventing a plurality of the elevator cars greater than the first number from answering calls registered by the first call registering means, and for conditioning the last-named plurality of the elevator cars for reversal at the farthest registered call in the first direction which such elevator cars are conditioned to answer.

27. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to the structure in combination with control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at said landings, said control means including means responsive to a first condition for modifying the operation of part only of said elevator cars to provide a specialized elevator service for all of the landings, and means responsive to a second condition for modifying the operation of all of said elevator cars to provide said specialized service for all of the landings.

28. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to thestructure in combination with control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at said landings, said control means including means responsive to a first condition for modifying the operation of part only of said elevator cars to provide a specialized elevator service for all of the landings, and means responsive to a second condition for modifying the operation of all of said elevator cars to provide said specialized service for all of the landings, and resetting l means effective following each trip of one of the elevator cars providing said specialized elevator service for resetting such elevator car for normal service.

29. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality f elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to the structure in combination with car call means for each of the elevator cars for registering calls for landings desired by passengers entering the elevator cars, control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at said landings, said control means including means responsive to a first number of registered car calls in a portion only of said elevator cars for modifying the operation of part only of said elevator cars to provide a specialized elevator service for all of the landings, and means responsive to a second number of registered car calls in a portion of said elevator cars greater than said first named portion for modifying the operation of all of said elevator cars to provide said specialized service for all the landings.

30. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to the structure in combination with control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at said landings, said control means including means responsive to a first condition for expediting reversal of part only of said elevator cars during travel of such part only of the elevator cars in a first direction, and means responsive to a second condition for expediting reversal of all of said elevator cars during travel of the elevator cars in the first direction only if no service in the reversed direction is required for a landing displaced in the first direction from the elevator cars.

31. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to the structure in combination with control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at desired landings, said control means including means responsive to a first service demand for modifying the operation of part only of said elevator cars to provide a specialized elevator service for all of the landings, and means responsive to a second service demand for modifying the operation of all of said elevator cars to provide said specialized service for all of the landings.

32. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, motive means for moving the elevator cars relative to the structure in combination with control means operable in cooperation with the motive means normally to move each of the elevator cars between the terminal landings and to stop each of the elevator cars at desired landings, said control means including means responsive to a first service demand for expediting reversal of part only of said elevator cars during travel of such part only of the elevator cars in a first direction, and means responsive to a second service demand for expediting reversal of all of said elevator cars during travel of the elevator cars in the first direction only if no service in the reversed direction is required for a landing displaced in the first direction from the elevator cars.

33. An elevator system including a structure having a pair of terminal landings and a plurality of landings intermediate the terminal landings, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure, car call registering means for each of the cars for registering calls for landings desired by passengers entering the elevator cars, landing first-call registering means operable from each of a plurality of landings for registering calls for service in a first direction desired by prospective passengers at the landings, and landing second-call registering means operable from each of a plurality of the landings for registering calls for service in a second direction desired by prospective passengers at the landings, in combination with controlling means operable in cooperation with the motive means and the registering means for moving each of the elevator cars and for stopping each of the elevator cars during travel in the first direction at landings reached by the elevator car for which landing first calls or car calls are registered, and for stopping each of the elevator cars during travel in the second direction at landings reached by the elevator car for which landing second-calls or car calls are registered, conditioning means responsive to a predetermined registration by said car call registering means, and modifying means responsive to operation of the conditioning means for modifying the operation of a plurality of the elevator cars.

References Cited in the file of this patent UNITED STATES PATENTS 2,589,292 Santini Mar. 18, 1952 2,611,451 Larson Sept. 23, 1952