US2685349A

US2685349A - Multiple-car elevator system

Info

Publication number: US2685349A
Application number: US269503A
Authority: US
Inventors: William F Eames
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1952-02-01
Filing date: 1952-02-01
Publication date: 1954-08-03
Anticipated expiration: 1971-08-03

Description

Aug. 3, 1954 w, F. EAMES MULTIPLE-CAR ELEVATOR SYSTEM 7 Sheets-Sheet 1 Filed Feb. 1, 1952 Fig.2. Car Floor High Call Call FIOOI' Cm Cancel Cull Coll & m R 00 H M m ECI. O V mm fln .mf Wm WITNESSES: 4 @441 y 5% W. F. EAMES MULTIPLE-CAR ELEVATOR SYSTEM Aug. 3, 1954 7 Sheets-Sheet 2 Filed Feb. 1, 1952 INVENTOR WITNESSES: 67%

\villiom F.Edmes.

ATTORNEY Aug. 3, 1954 Filed Feb. 1, 1952 W. F. EAMES MULTIPLE-CAR ELEVATOR SYSTEM 7 Sheets-Sheet 4 Patented Aug. 3, 1954 UNITED STAiEfi ih iENT OFFICE MULTIPLE-CAR ELEVATOR SYSTEM Application February 1, 1952, Serial No. 269,503

12 Claims. 1

This invention relates to elevator systems, and it has particular relation to an elevator system employing a bank of elevator cars wherein at least part of the elevator cars are conditioned under predetermined circumstances to reverse at an intermediate floor served by the elevator cars.

In order to avoid unnecessary car travel and to expedite service to fioors of a building served by elevator cars, the elevator cars often are arranged to reverse at an intermediate floor. Although such reversal may occur for a down-traveling elevator car, it is more commonly encountered for lip-traveling elevator cars and will be discussed with reference to such cars.

In a bank of elevator cars, two or more elevator cars may be traveling up at the same time. If a leading up-traveling elevator car reaches a floor representing the highest call for elevator service, the arrival of the leading car cancels the call and conditions the leading car for travel in the down direction. If no other calls are registered requiring further up travel of one of the trailing cars, the cancellation of the call by the leading car results in a reversal of such trailing car. The simultaneous reversal of two or more elevator cars of the bank often results in a poor distribution of elevator cars and impairment of service for certain floors of the building, particular the higher floors, and particularly during periods of heavy down travel.

In accordance with the invention, the distribution of elevator cars and the service for higher floors of the building are improved by preventing the reversal of a trailing elevator car if a leading elevator car cancels the only registered call for service requiring further up travel of the elevator cars. Under such circumstances, one or more of the trailing elevator cars may be forced to travel to the upper terminal floor before it can be reversed. If a call for service is registered between the trailing and leading elevator cars at the time the leading elevator car cancels the highest call for service, a trailing elevator car may be conditioned for reversal at the highest of the intermediate calls for service.

It is therefore an object of the invention to provide an improved elevator system including a bank of elevator cars wherein at least part of" the elevator cars are conditioned to reverse when the farthest call in the direction of travel of the elevator cars has been reached.

It is a further object of the invention to provide a bank of elevator cars wherein reversal of a leading elevator car at an intermediate floor conditions a trailing elevator car to continue in the same direction to a terminal floor.

It is also an object of the invention to provide a bank of elevator cars, as defined in the preceding paragraph, wherein the presence of a registered call for service intermediate the leading and trailing elevator cars conditions the trail ing elevator car to reverse at the farthest of the intermediate calls for service.

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

Figure 1 is a view in elevation with parts broken away of an elevator system embodying the invention;

Fig. 2 is a view in elevation with parts broken away of a floor selector suitable for the system of Fig. 1;

Fig. 3 is a schematic view showing control circuits suitable for the system of Fig. 1;

Fig. 3A is a schematic view showing electromagnetic switches and relays employed in the circuits of Fig. 3. If Figs. 3 and 3A are placed in horizontal alignment, it will be found that the respective contacts and coils of the two figures are substantially in horizontal alignment.

Fig. i is a schematic View in straight line form showing iloor call circuits suitable for the system of Fig. 1;

Fig. 4A is a schematic view showing electromagnetic switches and relays employed in the circuits of Fig. i. If Figs. 4 and 4A are placed in horizontal alignment, it will be found that corresponding contacts and coils of the two figures are substantially in horizontal alignment.

Fig. 5 is a schematic view in straight line form showing additional circuits suitable for the systern of Fig. l; and

Fig. 5A is a schematic view of electromagnetic switches and relays employed in the circuits of Fig. 5. If Figs. 5 and 5A are placed in horizontal alignment, it will be found that corresponding coils and contacts of the two figures are substantially in horizontal aligrment.

The invention is suitable for banks of elevator cars including various numbers of cars serving buildings having various numbers or floors. However, the invention may be discussed adequately for a bani; of elevator cars having four cars A, B, C and D, serving a building having seven floors.

Inasmuch as the elevator cars of the bank have similar control circuits, it will suffice to discuss the control circuits for the elevator card.

Similar components for the remaining elevator cars are identified by the same reference characters preceded by the letter corresponding to the appropriate elevator car. For example, the reference character E designates the slowdown inductor relay for the elevator car A, whereas the reference character BE designates the slowdown inductor relay for the car B.

Electromagnetic relays and switches employed in the elevator system may have break contacts which are closed when the relays and switches are deenergized and dropped out. Also, the relays and switches may have make contacts which are closed when the switches and relays are energized and picked up. Break contacts are open when the switches and relays are energized and picked up, whereas make contacts are open when the switches and relays are deenergized and dropped out.

In order to distinguish the sets of contacts employed for each relay, each set will be designated by the reference character for the relay followed by the numeral corresponding to the specific set of contacts. For example, th reference character U3 designates the third set of contacts for the up switch U.

In order to facilitate the consideration of the invention, the following apparatus is listed:

Apparatus for car A- VHigh-speed relay UUp switch DDown switch GInductor holding relay ESlowdown inductor relay E -Stopping inductor relay lVl-Car running relay WUp-direction preference relay X-Down-direction preference relay H-I-ligh car-call relay TCar-call stopping relay SFloorcall stopping relay K-Hig'h floor-call relay LAuxi1iary high floor-call relay N-Lockout relay JReversing relay Apparatus common to all cars- ZUR to iURUp call-storing relays 'ZDR to iDR-Down call-storing relays Figure 1 Fig. 1 shows the mechanical arrangement of various parts of the elevator system. In Fig. 1, a cable ll! passes over a sheave ll and has its ends attached respectively to the elevator car A and to a counterweight l2. The sheave H is secured to the shaft is of a driving motor i i. A conventional spring-applied electromagneticallyreleased elevator brake l5 is associated with the shaft of the motor IS.

in the operation of the elevator cars, certain contacts are made or broken as each elevator car reaches predetermined positions in its hoistway. Although each elevator car may actuate suitable switches located in the hoistway, it is common practice to provide a floor selector for this purpose. A typical fioor selector i6 is illustrated for th car A.

The floor selector It has a brush carriage H on which suitable brushes are mounted for movement relative to contact segments in accordance with motion of the elevator car. In Fig. 1 two brushes 32 and iii are illustrated which coact respectively with rows of contact segments b2, etc., and 92, etc. The arrangement of the contact segments will be discussed further in connection with Fig. 2.

Th brush carriage I? may be reciprocated in accordance with movement of the elevator car, but at a much slow-er rate, by means of a screw H; which is coupled to the shaft l3 through suitable gearing.

The elevator cars may be of the automatic type which are controlled entirely by passengers desiring elevator car service. However, for present purposes, it will be assumed that elevator cars are of the attendant-operated type. Thus, the elevator car A has a switch CS which is operated by the car attendant to engage a contact CSl when the elevator car is to start. The elevator car also has a number of car-call push buttons 20 to lo. The numeral for each car-call push-button reference character designates the floor with which the push button is associated. Thus, if a passenger desires to be discharged at the seventh floor, the car attendant would press the push button To.

A slowdown inductor relay and a stopping inductor relay F are employed in conditioning the elevator car A to stop at a floor. When the elevator car is to stop at a floor, the coil for the slowdown inductor relay E is energized. Such energization does not result in pickup of the break contacts El and E2 until the elevator car reaches predetermined positions wherein the inductor relay is adjacent a magnetic inductor plate UEP or DEP. One of the inductor plates UEP is provided for each of the floors at which the elevator car A is to stop during up travel. When the elevator car is a predetermined distance from a floor at which it is to stop, the up-inductor plate UEP for the floor is adjacent the inductor relay E and completes a magnetic circuit for opening the break contacts El. Such opening initiates a slowdown of the elevator car.

In a similar manner, a down-inductor plate DEP is provided for each floor at which the elevator car is to stop during down travel. When the elevator car approaches a fioor at which it is to stop, the inductor plate DEP completes a magnetic circuit for the inductor relay E to open the break contacts E2 and initiate a slowdown of the elevator car A.

In a somewhat similar manner the stoppinginductor relay F cooperates with up inductor plates UFP and down-inductor plates DFP to bring the elevator car to a stop at any desired floor. Thus, when the elevator car approaches a floor at which it is to stop when traveling in the up direction, one of the inductor plates U'FP completes a magnetic circuit for the inductor relay to open the break contacts Fl. If the elevator car is traveling in a down direction, one of the inductor plates DFP cooperates with the inductor relay to open the break contacts F2 a short distance in advance of the floor at which the elevator car is to stop. Such inductor relays are well known in the art.

Calls for elevator car service from passengers located at Various floors served by the elevator cars are registered by suitable push buttons located at the various floors. For example, at the second floor, an up push button 2U may be operated to register a call for up elevator car service. A similar push button would be located at each floor from which up elevator car service is desired. Each up push button is identified by the reference character U preceded by a numeral corresponding to the floor at which the push button is located. Each up push button is common to all of the elevator cars. In an analogous manner, a down push button (identified by the letter D preceded by a numeral corresponding to the floor at which the push button is located) is located at each hall or floor from which down elevator car service is .desired. The down-call push button 2D is illustrated in Fig. 1 for the second floor.

Figure 2 Fig. 2 shows in greater detail the arrangement of the contact segments, brushes, switches, employed in the floor selector I6. Relays H, T, S, K, L, which are associated with the floor selector are shown in other figures.

As the elevator car A moves upwardly, a brush 30 mounted on the brush carriage l'l successively engages contact segments a2-to al. This brush has a length sufficient to bridge successive contact segments and is employed in controlling a high car-call relay H. A brush 3l mounted on the brush carriage also engages successively the contact segments to control a car-call stopping relay T during up travel of the elevator car A. The numeral employed in each contact segment reference character designates the floor with which the contact segment is associated.

During up travel of the elevator car A, a brush 32 on the brush carriage l'l successively engages contact segments b2 to 136 to control a floorcall stopping relay S.

During up travel of the elevator car A, a brush 33 successively engages contact segments 02 to 06 for the purpose of cancelling floor calls for which the elevator car stops.

During up travel of the elevator car, a brush 34 mounted on the brush carriage successively engages contact segments dl to (Z6 for the purpose of controlling a high floor-call relay K and an auxiliary high call relay L. The brush 34 has a length suificient to bridge successive contact segments.

During down travel of the elevator car A, a brush ll mounted on the brush carriage successively engages contact segments fl to 1'2 for the purpose of cancelling down floor calls answered by the elevator car.

During down travel of the elevator car A, a brush 42 mounted on the brush carriage ll successively engages contact segments gl to 9 2 for the purpose of controlling the floor-call stopping relay S.

During down travel of the elevator car A, a brush 43 mounted on the brush carriage l'l successively engages contact segments he to M for the purpose of controlling the car-call stopping relay T.

During up travel of the elevator car A, a cam 49 successively opens normally closed mechanical switches 52 to 56, which are associated respectively with the second to the sixth floors. The cam 49 has a length sufficient to bridge the operating members of successive switches. These switches are employed in controlling the energization of the high call-car relay H.

Figure 3 Fig. 3 shows various control circuits for the elevator system. Although various motor drives may be employed for the system, it will be assumed that a drive of the variable-voltage type is employed. In such a drive, the motor I4 is a direct-current motor which has its armature MA energized from the armature GA of a directcurrent generator GE. The direct-current generator is rotated at a constant rate by a suitable motor (not shown). The armatures MA and GA, together with a generator series fiield winding GS, are connected by a circuit 22 in series in a loop circuit. The field winding HF for the motor I4 is connected directly to a source of direct current represented by the buses L-|-3 and L3.

The release coil for the brake I5 is connected for energization across the buses L+3 and L-3 either through make contactsUl of an up switch or make contacts D2 of a down switch.

The direction of travel of the elevator car A is determined by the polarization of the generator field winding GF. When the make contacts DI and D3 of the down switch are closed, the generator field winding is connected through a resistor Rl across the buses L+3 and L-3 for energization with proper polarity for down travel of the elevator car. If the generator field winding is connected through the resistor RI and the make contacts U2 and U3 of the up switch across the buses L+3 and L3, the polarity of energization of the field winding is suitable for up travel of the elevator car. Maximum speed of the elevator car is obtained by shunting the resistor RI through make contacts VI of a speed relay.

For up travel the speed relay V is energized through break contacts El of the slowdown inductor relay, normally-closed contacts of an upper cam-operated limit switch VTU and make contacts U4 of the up switch. If the elevator car is to slow down adjacent a floor at which it is to stop, the break contacts El of the slowdown inductor relay open to deenergize the speed relay V. Also, if the car reaches its upper limit of travel, a cam opens the limit switch VTU to deenergize the speed relay.

For down travel, the speed relay V is energized through break contacts E2 of the slowdown inductor relay, normally-closed contacts of a camoperated lower limit switch VTD and make contacts D4 of the down switch. If the elevator car is to slow down as it approaches a fioor at which it is to stop, the break contacts E2 open to deenergize the speed relay. If the car nears its lower limit of travel, a cam opens the lower limit switch VTD to deenergize the speed relay,

By manipulation of his car switch CS, a car attendant controls the initial energization of a car running relay M and. either the up switch U or the down switch D. The relays and switches can be energized only if certain safety devices 23 are in their safe conditions. These safety devices may include contacts which are closed only if the various hoistway doors and the car doors are closed.

It will be assumed that the elevator car stops automatically in response to registered car calls and registered floor or hall calls. If the elevatorcar is conditioned for up travel, make contacts WI of the up-direction preference relay are closed, and the following circuit is established by operation of the car switch:

L+3, CS, CSl, Wl, Fl, STU, U, M, 23, L3

This conditions the elevator car for up travel. It will be noted that energization of the up switch U results in closure of the make contacts U5 to establish a holding circuit around the car switch and the contacts WI Consequently, stopping of the elevator car is independent of the condition of the car switch.

When the elevator car A approaches a floor at which it is to stop, the stopping inductor relay finally opens its break contacts Fl to deener- 7 size the up switch U and the car running relay M. As the elevator car nears its upper limit of travel, a cam opens the normally-closed limit switch STU to deenergize the up switch U and the car running relay M.

If the elevator car is conditioned for down travel, the make contacts XI of a down-direction preference relay are closed. An operation of the car switch completes the following circuit:

L+i, CS, CS1, XI, F2, STR, D, M, 23, L3

Operation of the down switch D closes make contacts D5 to complete a holding circuit around the car switch and the contacts XI.

If the down-traveling elevator car approaches a iioor at which it is to stop, the stopping inductor relay finally opens its break contacts F2 to deenergize the down switch D and the car running relay M. As the elevator car nears its lower limit of travel, the normally-closed limit switch STD is opened by a cam to assure deenergization of the down switch D and the car running relay.

The coils of the inductor relays E and F, and the coil of an inductor holding relay G are energized through make contacts M of the car running relay, and any one of three sets of make contacts. Thus, if the elevator car is to stop in response to a car call, the make contacts Tl close to energize the coils. If the elevator car is to reverse at an intermediate floor, the make contacts J l of the reversing relay close to energize the coils. If the elevator car is to stop in response to a registered floor or hall call, the make contacts Si of the floor call stopping relay close x to energize the coils. When the inductor holding relay G is once energized, it closes its make contacts GI to establish a holding circuit until the contacts Mi of the car running relay open. The energization of the stopping inductor relay F also is controlled by break contacts V2 of the speed relay.

The Lip-direction preference relay W can be energized only if the elevator car is not traveling down (break contacts D5 are closed), the elevator car is not conditioned for down travel (break contacts X2 are closed), the reversing relay is not energized (break contacts J2 are closed), and the elevator car is not adjacent its upper limit of travel (normally-closed cam-operated switch SQT is closed) The up-direction preference relay W, when once energized, is deenergized in either of two ways. As the elevator car reaches its upper limit of travel, a cam opens the normally-closed limit switch SGT to deenergize the up-direction preference relay. In addition, if the elevator car is to reverse at an intermediate floor, the break contacts J 2 of the reversing relay open. Consequently, as the elevator car comes to stop at the intermediate floor, the make contacts M2 of the car running relay open to complete the deenergization of the up-direction preference relay.

The down-direction preference relay X can be energized only if the elevator car is not traveling up (break contacts US are closed), the up-direction preference relay W is not energized (break contacts W2 are closed), and the elevator car is not adjacent its lower limit of travel (limit switch 55313 is closed). When once energized, the downdirection preference relay can be deenergized only as it nears its lower limit of travel. Under such circumstances, a cam opens the normally-closed limit switch 30B to deenergize the down-direction preference relay.

Figure 4 Fig. 4 shows the circuits for controlling the up call-storing relays, the down call-storing relays and the floor-call stopping relay S.

When the second floor up call button 2U is pressed, the up call-storing relay EUR. is connected across the buses L+3 and L3. As a result of its energization, the relay closes its make contacts ZURi to establish a holding circuit around the push button 2U. It will be noted that the contact segments for all of the cars which control the stopping of up-traveling elevator cars at the second floor are connected to the bus L+3 through the make contacts ZURI. These contact segments include, for example, the contact segments 112 for the car A and the contact segments BbZ for the car B. Contact segments for additional cars would be similarly connected.

If the elevator car A is traveling up, make contacts W3 of the up-direction preference relay are closed, and when the brush 32 reaches the contact segment b2, the following energizing circuit is completed:

L+3, ZURi, b2, 32, W3, S, L3

The floor-call stopping relay now is energized to initiate the stopping of the elevator car A at the second floor. If another of the elevator cars, such as the car B, had been the first car to near the second floor while traveling up, a stepping operation thereof would be initiated in a similar manner.

If a stopping operation of the elevator car A at the second floor is initiated, the brush 33 engages the contact segments 02 and completes the following circuit:

L+3, ZURQ, ZURN, c2, 33, W4, G2, L-3

The resulting energization of the cancelling coil ZURN cancels the call at the second floor. The coil for the relay EUR and the coil ZURN may be wound in opposition so that the energization of the cancelling coil BURN results in resetting of the relay ZUR. Had another one of the elevator cars, such as the car B, been the first to answer the call of the second floor, the cancelling coil ZURN would have been energized through I the corresponding contact segment for such car.

It will be understood that a similar up call-storing relay and a similar cancelling coil would be associated in the same manner with each of the up call push buttons.

If a prospective passenger at the second floor presses the down-call push button 2D, the down car-storing relay 2BR is connected for energization across the buses L- -t and L3. This relay closes its make contacts 2BR! to establish a holding circuit around the push button. Contact segments for all of the elevator cars of the bank, such as the contact segment 92 for the car A and contact segment B 2 for the car B, now are connected through the contacts ZDR! to the bus L+3.

The first elevator car to approach the second floor while traveling down now completes an energizing circuit for its floor-call stopping relay. For example, if the elevator car A is the first to near the second fioor while traveling down, the brush 42 engages the contact segment 92 to complete the following circuit:

L-3, ZDRI, g2, 42, X3, S, L3

The energization of the floor-call stopping relay prepares the elevator car to stop at the second floor.

Following the initiation of the stopping operation at the second floor, the elevator car A has its brush 4| engage the contact segment f2 to complete the following circuit:

The resulting energization of the cancelling coil 2DRN resets the down call-storing relay ZDR in the same manner discussed for the relay ZUR. Had the elevator car B been the first to stop at the second floor, it would have completed a similar cancelling circuit through the contact segment Bf2.

If one of the elevator cars, such as the elevator car A while traveling up is conditioned to stop and reverse in response to a down floor call, a cancelling circuit for the down floor call is completed for the elevator car A through the contacts J3 and W5 which then shunt the contacts X4.

Each of the down floor or hall call push buttons has a similar down call-storing relay and a similar cancelling coil associated therewith in the same manner.

Figure 5 The upper part of Fig. 5 shows circuits for controlling the high car-call relays and the carcall stopping relays. Each of the car-call push buttons to To normally is open. However, when pressed, each button is held in its pressed condition until the elevator car reverses its direction of travel. Thus, each of the buttons may be constructed of magnetic material, and when pressed, may be maintained in its pressed condition by means of a holding coil 200 to Ice. The holding coils are connected in series across the buses L+3 and L3, either through make contacts WT or the make contacts X6 of the preference relays. These contacts both are momentarily open to reset the car-call push buttons when the elevator car reverses its direction of travel.

Each of the car-call push buttons for the intermediate floors when operated connects two contact segments to the bus L+3. Thus, th car-call push button 20, when pressed, connects the contact segments a2 and 7L2 to the bus L+3. The elevator car does not have passengers desiring the seventh floor during down travel, and consequently only one contact segment a! need be connected through the car-call push button To to the bus L+3.

If the elevator car A is traveling up, and if a car call is registered for the fourth floor, the brush 3| engages the contact segment a4 a predetermined distance in advance of the fourth floor to energize the car-call stopping relay T through the circuit:

L+3, 40, a4, 3!, WG, T, M4, L3

The car-call stopping relay then would initiate a stopping operation of the elevator car. The parts may be so related that the brush 3| leaves the contact segment shortly before the elevator car comes to a full stop.

If the elevator car A were traveling down with a passenger to be discharged at the fourth floor, the following circuit would be completed as the elevator car nears the fourth floor:

L+3, 40, H4, 43, X5, T, M4, L3

Consequently, the car-call stopping relay T again would be energized to initiate the stopping operation of the elevator car A at the fourth floor. The

10 parts may be so related that the brush 43 leaves the contact segment h4 shortly before the elevator car comes to a full stop.

The high car-call relay 1-1 when energized indicates the presence of a registered car call for a floor above the position of the elevator car. The mechanical switches 52 to 56 are employed in controlling the energization of this high car-call relay. It will be noted that one of the mechanical switches is connected across each successive pair of contact segments. The mechanical switches connected to the contact segments corresponding to the position of the elevator car or to the floor directly below the elevator car are opened by the cam :29 to prevent energization of the high carcall relay H through car-call push buttons for the lower floors. However, if any car-call push button is pressed for a floor above the position of the elevator car, a circuit is completed for the high car-call relay H through the intermediate mechanical switches. Thus, with the elevator car at the third floor, as shown in Fig. 5, if a car call is registered for the sixth floor, the following circuit would be completed.

The car-call circuits are standard in the art.

The reversing relay J is energized in order to reverse the direction of the elevator car at an intermediate floor. For the specific system herein shown, the reversing relay J is effective only during up travel of the elevator car. For the relay to be energized, no car calls must be registered for a floor above the position of the elevator car (break contacts HI are closed), the car must be traveling up (make contacts W8 are closed), no other elevator car is conditioned to reverse at an intermediate floor and no floor call is registered for a floor above the position of the elevator car (make contacts Kl are closed), and the lockout relay N is deenergized (break contacts N! are closed).

The high floor-call relay K, together with the auxiliary high floor-call relay L are controlled in part from a call above indicator circuit 50. This circuit includes break contacts for all of the call-storing relays connected in series. The contacts are so arranged that those associated with call-storing relays requiring up travel of the elevator car are located above the point of contact of the brush 34 with the contact segments d! to 15. The order in which the contacts are connected and the points of contact to the circuit 52 of the contact segments d! to (16 may be ascertained by inspection of Fig. 5. Such call above indicator circuits are well known in the art. It will be understood that each of the contact segments dl to dit is connected to each of the corresponding contact segments for other elevator cars in the bank.

The high floor-call relay K can be energized only if no floor call for a floor above the position of the elevator car is registered (all break contacts of the call-storing relays above the position of the brush 34 are closed), the elevator car A is traveling up (make contacts W3 are closed), no other elevator car of the bank is conditioned to reverse at an intermediate floor (break contacts BKZ, CK3 and DK3 are closed), and the lockout relay N is deenergized (break contacts N2 are closed).

The auxiliary high floor-call relay L can be energized only if no floor call is registered requiring up travel of the elevator car (break contacts for the call-storing relays associated with floors ll above the position of the brush a l are all closed), and if the elevator car A is traveling up (make contacts W9 are closed).

The lockout relay N is intended to prevent reversal of the car A at an intermediate floor under certain conditions. For the lookout relay N to be energized, the elevator car A must be traveling up (make contacts W it are closed). In addition, the car A must not be conditioned for reversal at an intermediate iioor (break contacts K3 are closed). Furthermore, no floor call must be registered requiring up travel of the elevator car (make contacts L! are closed). Finally, floor call must be registered for a floor above the position of at least one other of the elevator cars (make contacts BLZ, GL2 or DL2 are closed). If these conditions all obtain, the lookout relay N picks up and closes its make contacts N3 to establish a holding circuit. The holding circuit maintains the lookout relay N energized until the elevator car A reaches its upper terminal floor whereupon contacts W9 of the up-direction preference relay open. As long as the lookout relay N is energized, the break contacts Ni are opened to prevent a reversal of the car A at an intermediate floor. Also, opening of the break contacts N2 prevents energization of the high floor-call relay K.

Operation It is believed that an understanding of the invention will be facilitated by a brief review of a typical operation of the elevator system. it will be assumed initially that the elevator cars are located at the lower terminal floor and that a down floor call is registered for the sixth floor. By reference to Fig. 4, it will be noted that the registration of the floor call is eiiected by pressing the push button SD which energizes the down call-storing relay BDR. The down call-storing relay closes its make contact tDRi to establish a holding circuit around the push button an and to connect the contact segments gfi and corresponding segments for the remaining cars to the bus -1-3, As shown in Fig. 5, the down callstoring relay 6BR also opens its break contacts EDRZ to prevent energization of the high floorcall relay K and of the auxiliary high floor call relay L.

Since the elevator car is at the lower terminal floor, the limit switch BQE (Fig. 3) is open, and the down-direction preference relay is deenergized. Also, the upper limit switch 331 closed, and the up-direction preference relay W is energized.

The elevator car attendant now operates the car switch CS and closes the doors of his car to complete the following circuit:

L+3, CS, CSl, W1, Fl, STU, U, M, 23-, L3

Energization of the car running relay M has no immediate effect on the operation of the system. However, the up switch U closes its make contacts Ui to release the brake is. Closure of make contacts U2 and U3 connects the generator field winding G? with proper polarity for up travel of the elevator car, and the elevator car starts in an up direction. Make contacts Ud close to energize at the speed relay V through the limit switch VTU and the contacts El or the slowdown inductor relay. The speed relay thereupon closes its make contacts V! to shunt the resistor RE and permit full speed operation of the elevator car. Also, the speed relay opens its break contacts V2 to prevent energization of the stopping inductor relay F. 7

Closure of the make contacts U5 establishes a holding circuit around the car switch and the contacts Wi. The car switch now may be released. Break contacts Ut open to prevent energization oi the down-direction preference relay X.

As the elevator car A in its upward travel passes the fourth floor, it will be assumed that the elevator car B starts from the lower terminal floor. The sequence for starting the elevator car B will be understood from the foregoing discussion of the starting of the elevator car A.

Turning now to Fig. 5, it will be noted that as the elevator car A approaches the sixth floor the brush 3 finally engages the contact segment (16 which connected to the call above indicator circuit 5% above the open contacts GDRZ. Since none of the other elevator cars is assumed to be in condition to reverse at an intermediate floor, the break contacts BKZ, CK3, and DKS are closed. Also, the lookout relay N is assumed to be de energized and its contacts N2 are closed. Consequently, the high floor-call relay K is energized through the circuit:

L+3, 'JDRZ, BURZ, d6, 34, W9, K, 3K2, CK3, DK3,N2,L3

It will be noted that the auxiliary high floor-call relay L also is energized.

As a result of its energization, the high floorcall relay K closes its make contacts KI to complete an energizing circuit for the reversing relay J. It is assumed that no car call is registered for a floor above the position of the elevator car A and that the break contacts H! are closed.

The high floor-call relay K, in addition, opens its break contacts in circuit with the high floorcall relays for the remaining elevator cars. For example, the contacts K2 open to prevent energization of the high floor-call relay BK for the carB.

The high floor-call relay K opens its break contacts K3 to prevent energization therethrough of the lookout relay N. Consequently, the elevator car A now is conditioned to stop and reverse at the sixth floor.

As a result of its energization, the reversing relay J closes its make contacts J 2 to establish a holding circuit around the contacts Ki. In addition, the reversing relay closes its make contacts J i (Fig. 3) to energize through the contacts Ml the coils of the inductor holding relay G and the inductor relay E.

Upon energization, the inductor holding relay G closes its make contact Gt to establish a holding circuit around the contacts J I. In addition, make contacts G2 (Fig. 4) close while the elevator car is still traveling up to answer a call, and such closure completes the following call-cancelling circuit:

L-l-3, SDRi, GDRN, s, $1, J3, we, o2, L-s

The cancelling of the call causes the relay EDR to drop to its deenergized position wherein the self-holding contacts GDR! are open. The break contacts GDRZ (Fig. 5) close and energize the relays K and L. Energization of the relay K and closure of contacts Ll have no immediate eiiect on the operation or" the system. Contacts L2 close to prepare the relay .BN for subsequent energization.

It is assumed that the elevator car B at this time is traveling up past the second floor, and that no corridor calls are registered for floors between the positions of the elevator cars A and 3. Under the assumed conditions, the following energizing circuit for the relay BL is established upon closure of the break contacts 6DR-2:

If any of the other elevator cars of the elevator system are conditioned for up travel at the same time, the corresponding relays, such as the relay CL or the relay DL, may be similarly energized and picked up under the assumed conditions.

The effect of energization and pickup of the relay BL will be considered below following completion of the discussion of the operation of the elevator car A which is now nearing the sixth floor.

Referring to Fig. 1, the coil of the slowdown inductor relay E for the elevator car A now is energized. When the inductor relay reaches the up-inductor plate UEP for the sixth floor, the magnetic circuit is completed which results in opening of the break contacts E I The opening of the break contacts El deenergizes the speed relay V (Fig. 3). Consequently, the make contacts VI open to introduce the resistor RI in series with the generator field winding GF. This slows the elevator car A to a landing speed. In addition, break contacts V2 open to energize the coil of the stopping-inductor relay F through the contacts GI and MI Upon continued movement of the elevator car towards the sixth floor, the stopping-inductor relay F (Fig. 1) reaches the up-inductor plate UEP for the sixth floor to complete a magnetic circuit which results in opening of the break contacts Fl. The opening of these contacts deenergizes the up switch U (Fig. 3) and the car running relay M.

As a result of its deenergization, the up switch U opens its contacts UI to deenergize the coil of the brake l and to permit the spring-applied brake to move into braking condition. In addition, the contacts U2 and U3 open to deenergize the generator field winding. The elevator car now stops at the sixth floor The up switch U opens its make contacts U4 and U5, and closes its break contacts U6. Such contact operations have no immediate effect on the system. The deenergization of the car running relay M results in opening of the make contacts Ml to deenergize the coils of the inductor holding relay G and of the inductor relays E and F. Also, make contacts M2 open. Since the reversing relay has, already opened the break contacts J 2, it follows that the up-direction preference relay W now is deenergized. Opening of the make contacts M3 (Fig. 5) has no immediate effect on the operation of the system.

The deenergization of the up-direction preference relay results in opening of the make contacts WL, W3, W4, W5, W6, W1, W8, W9 and Wlil without immediate effect on the operation of the system. However, the closing of the break contacts W2 (Fig. 3) completes an energizing circuit for the down-direction preference relay X through the lower limit switch 35B and the recently-closed break contacts U6 of the up switch.

The down-direction preference relay X closes its make contacts XI, X3, X5 and X5 to prepare the elevator car for operation in the down direction. Opening of the break contacts X2 (Fig. 3) prevents energization of the Lip-direction preference relay W. Closure of the make contacts X4 (Fig. 4) completes through the recently closed contacts M3 of the car running relay, the following cancelling circuit:

14 As a result of the continued energization of the cancelling coil BDRN, the down floor call for the sixth floor is held cancelled until the car leaves the floor on its down trip.

It will be recalled that the relay BL was energized following cancellation of the sixth floor call. Upon energization, the auxiliary high floorcall relay BL closes its make contacts associated with the lookout relays of the other elevator cars, such as the contacts BLZ, which are associated with the lockout relay N of the car A. However, since contacts K3 are open at this time, the closure of the contacts BL2 has no effect on relay N of the elevator car A.

At the time the relay BL closes its contacts BLI the break contacts BK3 are also closed (since the contacts K2 are open at such time, the relay BK cannot be energized. Inasmuch as the make contacts L2 also are closed, the following circuit is established:

L+3, L2, BLI, BK3, BN, BWID, L3

Consequently, the relay BN closes its make contacts BN3 to establish a holding circuit which is interrupted only when the elevator car reaches the upper terminal floor. In addition, break contacts BNI are opened to prevent energization therethrough of the reversing relay BJ for the car B. Consequently, the car B must proceed to the upper terminal floor and cannot reverse at an intermediate floor. The contacts BN2 open to prevent energization therethrough of the high floor-call relay BK. When the elevator car B reaches the upper terminal floor, the up-direction preference relay BW is deenergized as a result of opening of the upper limit switch B30T (Fig. 3). Due to such opening, the contacts BWIO (Fig. 5) open to deenergize the lookout relay BN.

Next, it will be assumed that immediately prior to the cancellation of the down floor call at the sixth floor by the elevator car A, a down floor call was registered at the fourth floor. Such registration was effected by the pressing of the button 4D (Fig. 4) to energize the down call-storing relay 4BR. This relay closed its make contacts 4DRI to establish a self-holding circuit and to connect the contact segment 94 and corresponding contact segments of the other cars to the bus L+3. In addition, the registered call resulted in opening of the break contacts 4DR2 (Fig. 5). It will be noted that this registered call is for a floor intermediate the leading car A and the trailing car B.

Since the elevator car B is below the floor corresponding to the open contacts 4DR2 at the time the call at the sixth floor is cancelled, the auxiliar high floor-call relay BL cannot be energized through the call above indicator circuit 50. Therefore, the make contacts BLI remain open and the locking relay BN cannot be energized. As the up-traveling elevator car B nears the fourth floor, an energizing circuit for the high floor-call relay BK is established as follows:

Consequently, the relay BK closes its contacts BKI to complete under the assumed conditions an energizing circuit for the reversing relay BJ. The reversing relay initiates a stopping and reversing of the elevator car at the fourth floor in the same manner by which the elevator car A was previously stopped and reversed at the sixth floor by the reversing relay J. It will be noted that the energized high floor-call relay BK also opens its contacts associated with the high floorcall relays of the remaining cars to prevent energization of such relays. As an example, the break contacts BKZ open to prevent energization of the high floor-call relay K for the car A.

Finally, it should be noted that the break contacts BK3 open to prevent energization of the lookout relay BN.

From the foregoing, it is clear that if a leading up-traveling car stops and reverses at an intermediate floor, and no calls for service are registered for a floor above the position of a trailing up-traveling elevator car, the trailing uptraveling elevator car is conditioned to continue traveling in the up direction, in this case to the upper terminal floor. However, if at the time of the reversal of the leading up-traveling elevator car, a call for a floor above the position of a trailing up-traveling elevator car exists, such as a floor call for a floor intermediate the positions of the two cars, the trailing elevator car is conditioned to proceed to the highest call for service and is stopped and reversed at the floor corresponding to such highest call for service.

Although the invention has been described with reference to certain specific embodiments there of, numerous modifications falling within the spirit and scope of the invention are possible. For this reason, the specific embodiments herein set forth are to be construed in an illustrative rather than a limiting sense.

I claim as my invention:

1. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, callregistering means for registering calls for elevator service for the floors, translating means responsive to arrival of each of the elevator cars adjacent the farthest floor in the direction of travel of the elevator car for which a call for service i registered for preparing the arriving elevator car for reversal, and conditioning means responsive to arrival of one of the elevator cars adjacent the farthest floor in the direction of travel of the elevator car for which a call is re istered for rendering the translating means of certain of the elevator cars inefiective for preparing said certain of the elevator cars for reversal.

2. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, callregistering means for registering calls for elevator service for the floors, translating means responsive to arrival of each of the elevator cars adjacent the farthest floor in the direction of travel of the elevator cars for which a call for service is registered for preparing the arriving elevator car for reversal, and conditioning means responsive to arrival of one of the elevator cars adjacent the farthest floor in the direction of travel of the elevator car for which a call is registered for rendering the translating means of certain of the elevator cars ineffective for preparing said certain of the elevator cars for reversal, said conditioning means including means responsive to the presence of at least one registered call for a floor intermediate a leading one and a trailing one of said elevator cars for conditioning said translating means of the trailing car for operation.

3. In an elevator system, a structure having a plurality of fioors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, callregistering means for registering calls for elevator service for the floors, translating means responsive to arrival of each of the elevator cars adjacent the farthest floor in the direction of travel of the elevator car for Which a call for service is registered, and condtioning means responsive to arrival of one of the elevator cars adjacent the farthest floor in the direction of travel of the elevator car for which a call is registered for rendering inefiective the translating means of certain of the elevator cars, the direction of travel of said certain of the elevator cars remaining unchanged until a predetermined terminal floor is reached by said certain of the elevator cars.

4. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, up callregistering means operable for registering calls for elevator up service from th floors, down call-registering means operable for registering calls for elevator down service from the floors, control means for causing the elevator cars during up travel to stop successively at floors for which up calls are registered as the cars reach such floors, said control means being effective during up travel of the elevator cars for stopping the elevator cars at an intermediate floor in response to a registered down call provided no call requiring further up travel of the elevator cars is registered, and conditioning means responsive to said stopping of one of the elevator cars during an up trip at an intermediate floor in response to a registered down call for requiring certain of the elevator cars to travel to a higher floor.

5. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, up call-registering means operable for registering calls for elevator up service from the floors, down call-registering means operable for registering calls for elevator down service from th floors, control means for causing the elevator cars during up travel to stop successively at floors for which up calls are registered as the cars reach such floors, said control means being efiective during up trave1 of the elevator cars for stopping the elevator cars at an intermediate floor in response to a registered down call provided no call requiring further up travel of the elevator cars is registered, and conditioning means responsive to said stopping of one of the elevator cars during an up trip at an intermediate floor in response to a registered down call for requiring certain of the elevator cars to travel to a higher floor, the control means including reversing means responsive to said stopping of the elevator car at a floor in response to the registered down call for conditioning the elevator car for down travel.

6. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, up call-registering means operable for registering calls for elevator up service from the floors, down call-registering means operable for registering calls for elevator down service from the floors, control means for causing the elevator cars during up travel to stop successively at floors for which up calls are registered as the cars reach such floors, said control means being efiective during up travel of the elevator cars for stopping the elevator car at an intermediate fioor in response to a registered down call provided no call requiring further up travel of the elevator cars is registered, and conditioning means responsive to said stopping of one of the elevator cars during an up trip at an intermediate floor in response to a registered down call for requiring certain of the elevator cars. to travel to a higher floor, said conditioning means being rendered inefiective to control a trailing up-traveling elevator car in response to the presence of a registered call for a floor intermediate the trailing elevator car and an elevator car leading the trailing elevator car.

7. In an elevator system, a structure havin a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, up call-registering means operable for registering calls for elevator up service from the floors, down call-registering means operable for registering calls for elevator down service from the floors, control means for causing the elevator cars during up travel to stop successively at floors for which up calls are registered as the cars reach such floors, said control means being effective during up travel of the elevator cars for stopping the elevator cars at an intermediate floor in response to a registered down call provided no call requiring further up travel of the elevator cars is registered, and conditioning means responsive to said stopping of one of the elevator cars during an up trip at an intermediate floor in response to a registered down call for requiring certain of the elevator cars to travel to a higher floor, said conditioning means being rendered inefiective to control a trailing up-traveling elevator car in response to the presence of a registered call for a floor intermediate the trailing elevator car and an elevator car leading the trailing elevator car, and said conditioning means bein effective for stopping the trailing elevator car in response to a registered down call provided no call requiring further up travel of the trailing elevator car is registered.

8. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, up call-registering means operable for registering calls for elevator up service from the floors, down call-registering means operable for registering calls for elevator down service from the floors, control means for causing the elevator cars during up travel to stop successively at floors for which up calls are registered as the cars reach such floors, said control means being efiective during up travel of the elevator cars for stopping the elevator cars at an intermediate floor in response to a registered down call provided no call requiring further up travel of the elevator cars is registered, and conditioning means responsive to said stopping of one of the elevator cars during an up trip at an intermediate floor in response to a registered down call for requiring certain of the elevator cars to travel to a higher floor, said conditioning means being rendered ineffective to control a trailing up-traveling elevator car in response to the presence of a registered call for a fioor intermediate the trailing elevator car and an elevator car leading the trailing elevator car, said conditioning means being effective for stopping the trailing elevator car in response to a registered down call provided no call requiring further up travel of the trailing elevator car is registered, and the control means including reversing means responsive to said stopping of the trailing elevator car at a fioor in response to the registered down call for conditionin the trailing elevator car for down travel.

9. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, first call-registering means operable for registering calls for elevator service in a first direction from the floors, second call-registering means operable for registering cal for elevator service in a second direction from the floors, control means for causing each of the elevator cars during travel in the first direction to stop successively at each of the floors approached by each of the elevator cars for which a call is registered by the first call-registering means, said control means ineluding translating means effective for initiating a stopping and reversal of each of the elevator cars during travel in the first direction at an intermediate one of said floors reached by such elevator car for which a call is registered by the second call-registering means provided no call is registered by the first call-registering means for such intermediate floor and provided further that no call is registered by the first and second call-registering means for a floor beyond such intermediate floor in the first direction, and conditioning means responsive to said initiation of a stopping and reversal of one of the elevator cars for renderin ineifective the translating means for certain of the elevator cars.

10. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, first call-registering means operable for registering calls for elevator service in a first direction from the floors, second call-registering means operable for registering calls for elevator service in a second direction from the floors, third callregistering means for each of the elevator cars operable for registering calls for floors desired for the load within each of the elevator cars, control means for causing each of the elevator cars during travel in the first direction to stop successively at each of the floors approached by each of the elevator cars for which a call is registered by the third call-registering means for such approaching elevator car or by the first call-registering means, said control means including translating means effective for initiating a stopping and reversal of each of the elevator cars during travel in the first direction at an intermediate one of said floors reached by such elevator car for which a call is registered by the second call-registering means provided no call is registered by the first call-registering means for such intermediate floor and provided further that no call is registered by the third call-registering means of the elevator car reaching such intermediate fioor or by the first and second callregistering means for a floor beyond such intermediate floor in the first direction, and conditioning means responsive to said initiation of a stopping and reversal of one of the elevator cars for rendering ineffective the translating means for certain of the elevator cars.

11. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, first call-registering means operable for registering calls for elevator service in a first direction from the floors, second call-registering means operable for registering calls for elevator service in a second direction from the floors, third callregistering means for each of the elevator cars operable for registering calls for floors desired for the load within each of the elevator cars, control means for causing each of the elevator cars during travel in the first direction to stop successively at each of the floors approached by each of the elevator cars ior'which a call is registered by the third call-registering means for such approaching elevator car or by the first callregistering means, said control means including translating means efiective for initiating a stopping and reversal of each 'of the elevator cars during travel in the first direction at an intermediate one of said floors reached by such elevator car forwhicha call-is registered by the second call ifgi'sterin'g' means provided no call is registered by the fiijst call-registering means for such 'interm'ediat e'fioor and provided further that no call is registered by the third "call-registering means of-the elevator car reaching such intermediate fioor 'orfby the first and'second callregistering nieans-for"a-floor beyond such intermediate" fioor the first direction; and conditioning means-responsive to said initiation of a stopping' and reversal of cheer the elevator cars for rendering inefl'ective-the translating means for certain of the elevator cars, said conditioning means, in'response to the presence or a call registered by the first or second call-registering means'for a floor intermediate the elevator car for which said stopping and reversal is initiated and a trailing elevator car, being rendered ineffective to control said trailing elevator car.

12. In an elevator system, a structure having a plurality of floors, a plurality of elevator cars, means mounting the elevator cars for movement relative to the structure to serve the floors, first call-registering means operable for registering calls for elevator service in a first direction from Lil 20 the floors, second call-registering means operable for registering calls for elevator service in a second direction from the floors, third call-registering means for each of the elevator cars operable for registering calls for floors desired for the load within each of the elevator cars, control means for causing each of the elevator cars during travel in the first direction to stop .successively at each of the floors approached by each of the elevator cars for which a call is registered by the third call-registering means for such approaching elevator car. or by the first callregistering means, said control means including translating means effective for initiating a stopping and reversal of each of the elevator cars during travel in the first direction at an intermediate one of said floors reached by such elevator car for which a call is registered by the second call-registering means provided no call is registered by the first call-registering means for such intermediate floor and provided further that no call is registered by the third call-registering meansof the elevator car reaching such intermediate fioor-or by the first and second-callregistering means for a floor beyond such intermediate floor in the first direction,- and,-conditioning means responsive to said initiation of a stopping and reversal of one of the elevator cars for rendering ineffective the translating means for certain of the elevator cars; said conditioning means; in response to the-presence of-acall reg-, istered by the firstor second call registering means'for' a floor intermediate the elevator car for which'said stopping and reversal is initiated and a trailing elevator car, being rendered inef-' fective to control said trailing elevator car, said conditioning means being effective for initiating a stopping and reversing of the trailing elevator car at an intermediate floor approached by the trailing elevator car for which a call is registered by the second call-registering means, provided no call is registered by the third call-registering means for such trailing elevator car or by the first or second call-registering means for a floor beyond the last-named intermediate floor in the first direction or by the first call-registering means of the last-named intermediate floor.

No references cited.