US3022866A

US3022866A - Lift systems

Info

Publication number: US3022866A
Application number: US771802A
Authority: US
Inventors: Bailey William John
Original assignee: J&E Hall Ltd
Current assignee: J&E Hall Ltd
Priority date: 1957-11-13
Filing date: 1958-11-04
Publication date: 1962-02-27
Anticipated expiration: 1979-02-27

Description

Feb. 27, 1962 Filed Nov. 4, 1958 W. J. BAILEY LIFT SYSTEMS '7 Sheets-Sheet 1 Feb. 27, 1962 w. J. BAILEY 3,022,866

LIFT SYSTEMS Filed Nov. 4, 1958 7 Sheets-Sheet 2 0/45 RF sea L TPB/ BRIE W. J. BAILEY Feb; 27, 1962 LIFT SYSTEMS Filed Nov. 4, 1958 7 Sheets-Sheet 3 W. J. BAILEY LIFT SYSTEMS Feb. 27, 1962 7 Sheets-Sheet 4 Filed Nov. 4, 1958 W. J. BAILEY Feb. 27, 1962 LIFT SYSTEMS 7 Sheets-Sheet 5 Filed Nov. 4, 1958 .1 w RE MvSTJ wwsm m 2x3). WHEN mam m as T w w E Em T EXW Feb. 27, 1962 W. J. BAILEY LIFT SYSTEMS Filed Nov. 4, 1958 7 Sheets-Sheet 6 Feb. 27, 1962 w. J. BAILEY 3,022,866

LIFT SYSTEMS Filed Nov. 4, 1958 '7 Sheets-Sheet 7 United States Patent Ofifice 3,022,866 Patented Feb. 27, 1962 This invention relates to lift systems of the kind in which a plurality of cars serve a number of floors or landings. Each car may be provided with means for causing the car when travelling down and when a certain condition exists such as the car being loaded beyond a predetermined amount, to bypass down calls registered at floors by intending passengers waiting at these floors. When said certain condition arises whilst downward travelling cars are at higher floors, down landing calls at lower floors are liable repeatedly to be lay-passed.

It is a first object of the invention to provide means whereby by-passed down calls are attended to.

Other objects of the invention will become clear from the following description.

In the accompanying drawings which illustrate an embodiment of the invention:

FIGURE 1 is a circuit diagram of mechanism for selecting the mode of operation of a lift system,

FIGURE 2 is a circuit diagram of mechanism for providing, in said lift system, rejected call service, zoning, late car reversal and service in the opposite direction to a heavy up or a heavy down demand,

FIGURE 3 is a diagram of part of the motor circuit of one of the cars of the lift system, the part being that which registers and cancels car calls made in the car,

FIGURE 4 is a diagram of another part of the same motor circuit, the part being that which registers landing calls for the cars,

FIGURE 5 is a diagram of another part of the same motor circuit, the part being that which initiates stopping of the car at a floor for which a call has been registered for that car,

FIGURE 6 is a diagram of part of the circuit for controlling the direction selector and the indicating system associated with one of the cars of the lift system,

FIGURE 7 is a modified form of part of the circuit diagram of FIGURE 1,

FIGURE 8 is a modified form of part of the circuit diagram of FIGURE 2,

FIGURE 9 is a modified form of part of the diagram of FIGURE 4, and

FIGURE 10 is a modified form of part of the diagram of FIGURE 5. V

The lift system is a modified form of that disclosed in my United States Patent No. 2,847,090 in which a plurality of cars serve a number of floors or landings. The systems exemplified in the prior specification and in this specification each employ three cars A, B and C which serve seven floors, the second floor being the main floor (which may be the ground floor) and the first floor being a basement. The cars (except the last car to be still working which remains as a free car at the floor to which it is last called) are arranged upon completion of a trip to return to a particular floor. This floor is termed the despatching floor. Movement of each car is initiated either by a car call which is made by a person in the car and who desires to travel to a certain floor, or by a landing call that is initiated by a passenger waiting at one floor and who desires to travel to another floor. Landing calls are supervised by a despatch signal initiating system to determine whether a landing call can conveniently be attended to by alcar already on a trip or whether a further car that is waiting at the despatching floor should be despatched to attend to the landing call. The despatch signal initiating system selects the order for despatching of the cars and is arranged to delay the despatch signal until the expiry of a predetermined despatch interval, the despatch interval for each car being initiated when the despatch signal is given to the previously selected car. Thus the despatch interval is an interval during which a car cannot be despatched to respond to a landing call. The system is arranged for selecting either the upper terminal floor or the main floor as the despatching floor.

When the main floor is selected as the despatching floor the system is said to be on up despatch and when the upper terminal floor is selected as the despatching floor the system is said to be on down despatch. Means are provided for varying the despatch interval, either to be a long interval or to be a short interval. In the system of the aforementioned patent a manual trafiic selection switch is provided and this switch has three operative positions. The switch is adjusted to its first operative position to deal with heavy down trafiic, to its second operative position to deal with normal trafiic conditions and to its third operative position to deal with heavy up trafiic. The first position is known as down peak and in this position the system is caused to operate with downward despatch and with the shorter despatch interval. In the third position which is known as up peak the system is caused to operate with upward despatch and the shorter despatch interval. In the second operative position which is the normal position for balanced trafic the system operates on upward despatch with a variable despatch interval, the despatch interval being arranged to be long or short according to the position of the cars in the hatchways, the directions of travel of the cars and whether the cars are under despatch. (A car is under despatch when it has received its despatch signal but has not yet departed from the despatching floor.)

The circuit shown in the accompanying FIGURE 1 replaces the manual means of Patent No. 2,847,090 for selecting the mode of operation of the lift system, by mechanism for automatically selecting the mode of operation,

in accordance with the traliic conditions of the system. The mechanism shown in FIGURE 1 is very similar to that described in my co-pending United States application No. 706,836, now Patent No. 2,867,293, the chief difference being that whereas the system of application No. 706,- 836, now Patent No. 2,867,293, selects between four modes of operation, the present system selects between the three modes already mentioned and omits the balanced peak mode of application No. 706,836, now Patent No. 2,867,- 293. When on up peak the lift system now to be described causes some of the cars to by-pass down landing calls and when on down peak causes some of the cars to bypass up landing calls.

, Before referring in detail to the accompanying drawings certain conventions will now be explained. In order to distinguish the pairs of contacts controlled by each relay, each pair is designated by the reference character for the relay followed by a numeral corresponding to the specific pair of contacts. For example, the contacts USRI are the first pair of contacts associated with the up peak selector relay coil USR. Certain of the coils and contacts are common to all the cars and others are specific to a particular car A, B or C. Where the last letter in the reference of a coil or a pair of contacts is A, B or C, that coil or pair of contacts is specific to the car A, B or C respectively. If the last letter of the reference is not A, B or C, the coil or pair of contacts is associated with apparatus common to all the cars. Thus the contacts USRAI controlled by the coil USR are a pair of contacts specific to the car A. A numeral-appearing in a reference before the last letter of the reference indicates that the coil or pair of contacts to which aoaaeee 3 the reference applies is associated with the floor corresponding to the numeral.

For facilitating an understanding of the lift system, the following apparatus is listed:

LSRA, LSRB, LSRC-load switch relay coils;

UA, UB, UC--up main relay coils;

DA, DE, DC-down main relay coils;

TW, TX, TY, TZ-ti.mers;

UPTup peak hold relay coil;

DPT-down peak hold relay coil;

ULA, ULB, ULCup load relay coils;

DLA, DLB, DLC-down load relay coils;

USR-up peak selector relay coil;

DSR-down peak selector relay coil;

MSSmanual selector switch;

CSS-clock selector switch;

313C to 6BCby-passed call relay coils;

R-resistance;

Ccapacitance;

lBTrejected call relay coil;

XBT-zoning relay coil;

XBTXauxiliary zoning relay coil;

RCA, RCB, RCC-rejected call car relay coils;

LCR-late car reversal relay coil;

TPA, TPB, TPC-time pass relay coils;

AR, BR, CR-auxiliary time despatch relay coils;

ULXA, ULXB, ULXC-coils for controlling down serve ice when the system is on up peak;

DLXA, DLXB, DLXCcoils for controlling up service when on down peak;

1A to 7A-car call press button switches in the car A corresponding to seven fioors of the lift system;

IRA to 7FA-car call relay coils for the car A;

ARAauto-return relay coil for the car A;

AR7A--auxiliary auto-return relay coil for the car A;

CHA-call hold relay coil for the car A;

UIA-up direction selection relay coil for the car A;

LlU to L6Uup direction landing call relay coils for floors 1 to 6;

L21) to L7D-down direction landing call relay coils for the floors 2 to 7;

1UA to 6UA and ZDA to 7DA-landing call relay coils for the car A;

HSRA-slow-down relay coil for the car A;

URA-up directional relay coil;

DRA-down directional relay coil;

TBU-up time reverse relay coil;

TBDdown time reverse relay coil;

LUAup reverse relay coil;

LDAdown reverse relay coil.

Some of the relay coils listed above do not appear on the drawings but contacts associated therewith do and their operation is described hereinafter.

Selection of mode of operation Referring now to FIGURE 1 it will be seen that one side of the up peak hold relay coil UPT is connected to a positive line P and the other side of this coil is connected to the anode A of a valve V1 of the timer TX. The cathode K of this valve is connected to a negative line N. The grid G of the valve V1 is connected to a junction point 1P1 and this point is connected by three parallel paths to the positive line P. The first path contains series connected contacts LSRAI and UAI, the second path contains series connected contacts LSRBI and UB1 and the third path contains series connected contacts LSRCl and UCZ. Each car has a load switch (not shown) which when the car is loaded to a predetermined amount closes and causes energisation of the associated load switch relay coil. When a car is travelling upwardly its associated up main relay coil is energised. Thus when, say, the car is travelling upwardly and is loaded sufficiently to close its load switch the contacts LSRBl will be closed and contacts UB1 will also be closed so that the grid G of the valve V1 will have the potential of the line P applied thereto and the valve V1 will conduct so that the coil UPT will become energised. A capacitative circuit is provided between the grid G and the cathode K so that the valve V1 does not stop conducting until a predetermined time say, two minutes, after the connection between the grid G and the line P has been interrupted.

The down peak hold relay coil DPT is associated with circuitry very similar to that of the coil UPT and operates similarly except that it becomes energised when any one of the cars, say car A, is travelling downwardly and its load switch is closed, in which case the contacts LSRAI and DAl will be closed to cause the valve V2 of the timer TY to conduct.

It is to be noted that if the coil UPT is energised through loading of one upwardly travelling car which subsequently becomes sufiiciently unloaded to open the circuit between the point 3P1 and the line P and another car travelling upwardly becomes sulficiently loaded for its load switch to be operated before the expiry of the delay period for the valve V1 the coil UPT remains energised. The coil UPT, in fact, remains energised until the expiry of the predetermined time after all the three paths between point 5P1 and the line P have become open. The position is, of course, similar where the coil DPT is concerned.

One side of the up load relay coil ULA is connected to the line N and the other side is connected through series connected contacts UA2 and LSRAZ to the line P. Thus whenever the car A is travelling upwardly with its load switch closed the coil ULA becomes energised. Such a condition of the car A will also have caused the coil UPT to become energised so that the contacts UPTl close and a hold circuit for the coil ULA is established through the contacts UPTl and ULAl. Thus even though the car A reverses or becomes sufficiently unloaded for its lead switch to open, the coil ULA will not become de-energised until the coil UPT does and this may remain energised due to loading of another upwardly travelling car. The coils ULB and ULC associated with the cars B and C respectively operate similarly to the coil ULA. Similarly, the coils DLA, DLB and DLC operate similarly to the coils ULA, ULB and ULC but for the downward direction.

When all three of the coils ULA, ULB and ULC become energised the up peak selector relay coil USR is energised through the contacts ULA2, ULBZ and ULCZ provided the down peal; selector relay coil DSR is not previously energised. Energisation of the coil USR causes the lift system to operate on up peak. Similarly, if the coil USR is not energised and the coils DLA, DLB and DLC are all three energised, contacts DLAZ, DLBZ and DLCZ are closed so that the coil DSR becomes energised and the lift system operates on down peak." Whilst neither of the coils USR and DSR is energise the lift system operates for normal trafiic conditions.

The manual selector switch MSS can be positioned with its movable arm MA, which is connected to the positive line P, in one of three operative positions. in the first operative position the arm MA encounters a contact A, in the second operative position it encounters a contact B and in the third operative position it encounters a contact C. When in the first operative position the coils USR and DSR become energised as described above. When in its second operative position the coil USR is permanently energised and when in the third operative position the coil DSR is permanently energised.

A clock controlled switch CSS is provided and this switch has a movable arm MAC which rotates once every twenty-four hours. The movable arm is connected to the positive line P. For a period around 9 am. the arm touches an element E3. and for a period around 3 pm. the arm MAC touches an element E2. The elements E1 and E2 are connected through the coil USR to the negative line N. For a period around noon the arm MAC touches an element E3 and for a period around 6 pm. the arm touches an element E4. The elements E3 and E4 are connected through the coil DSR to the negative line N.

A transformer T has its primary winding P1 connected to an alternating current supply source and its secondary winding S1 supplies heating current to the cathodes of the valves V1 and V2.

It is thought that the manner in which the circuitry of FIGURE I automatically selects up peak, down peak or normal operation in accordance with the loading and direction of movement of the cars will be clear from the above brief description. However, a more detailed description of a very similar selecting mechanismappears in my co-pending patent application No. 706,836, now Patent No. 2,867,293. The operation of the selection mechanism is not described in detail herein since it does not form the subject of the present invention.

Car call registration Line L2, coil 4FA, resistance R, contacts 4FA1 and either closed contacts DSR4 or closed contacts DSRS and closed switch S2A2.

The switch SZAZ is located at the main floor and is closed except when the car A is at the ground floor.

Switches SlFA to S7FA are located at the floors 1 to 7 respectively and each is arranged to close when car A is at the associated floor. Each of the relay coils lFA to 7FA is of the kind that has two windings. One of the windings is connected in the line that includes the associated resistance R and the other Winding is connected in the line that includes the associated switch SIFA to S7FA as the case may be. When the car A arrives at the floor for which a car call has been registered, say the fourth floor, coil dFA will already have been energised. Upon arrival at the floor the switch S4FA becomes closed so that said other winding of the relay coil 4FA is energised through the circuit:

Line L2, resistance R, switch S4FA, said other winding, contacts 4FA1 and either the closed contacts DSR4 or closed contacts DSRS and closed switch S2A2.

Energisation of said other winding causes the relay coil 4FA to drop off so that registration of the car call for the fourth floor is cancelled.

When a car, say thecar A, is stationary at the despatching floor its associated coil CHA is ordinarily energised so that the contacts CHAI are open. Upon the car A leaving the despatching floor, however, the contacts CHAI close. One side of the auto-return coil ARA for the car A is connected to the line L2 and the other side of this coil is connected to one of the contacts of the pair CHAI through parallel connected contacts USRZ and DSR3. The other contact of the pair CHAI is connected to the line L1. When the lift system is operating on up or down peak one of the coils USR or DSR will be energised so that either the contacts USR2 or DSR3 will be closed. Thus when on up or down peak the coil ARA becomes energised whenever the car A moves away from the despatching floor. The coil ARA is also connected by a line L3 to be energised under other conditions as explained in Patent No. 2,847,090. Energisation of the coil ARA closes the contacts ARA1. If the system is operating on up peak the contacts DSR7 are closed so that whenever the car A moves away from the main fioor a car call is registered for the second floor through closure of the contacts ARAl and DSR7 whereby the car is caused to return to the main floor. If the system is operating on down peak the contacts DSR6 are closed so that the coil AR7A becomes energised through the closed contacts ARAI and DSR6 provided the car A has not been selected for rejected call service in which case the contacts RCA6 will be opened by circuitry to be described hereinafter. Assuming car A is not selected as the car to provide rejected call service and assuming the system is on down peak the coil AR7A becomes energised whenever the car A leaves the top terminal. The coil AR7A opens the contacts AR7A1 in FIGURE 5 and also closes contacts (not shown) appropriate to a seventh floor call in the circuitry (not shown) for selecting the direction of travel of the car A. This latter circuitry is described in detail in Patent No. 2,847,090.

Contacts RCAS and XBTAl are connected across the contacts DSR7. As described later when the system is operating on down peak and the car A is selected to provide service in a lower zone, the coils RCA and XBT will be energised so that the contacts RCAS and XBTAI will be closed, whilst the contacts RCAG will be open. Thus even though the system is operating on down peak, whenever the car A is selected for service in a lower Zone, it always has a second floor call registered therefor through closure of the contacts XBTAI, RCAS and ARAl. At this time the coil AR7A cannot be energised as the contacts RCA6 are open.

It will be understood that there is a circuit like that of FIGURE 3 for each of the cars B and C.

Registration of landing calls on a car Each intermediate landing has two landing call buttons, one for up service and the other for down service. Operation of the down call landing buttons for the floors 2 to 7 causes closure of the contactsLZDAl to L7DA1 (FIGURE 4) respectively. The up landing buttons for the floors 1 to 6 are respectively connected to close contacts LlUAl to L6UA1. The landing buttons are not shown in the accompanying drawings but are shown and described together with associated means for registering and cancelling landing calls, in said Patent No. 2,847,090. One contact of each of the pairs LlUAl to L6UA1 and L2DA1 to L7DA1 is connected to the positive line L1 and the other contact of each of these pairs is connected to an associated relay coil lUA to 6UA and 2DA to 7DA. These coils when energised register a landing call on the car A. Each of the down coils 2DA to 7DA is connected through a rectifier RF to a line L4 which is connected through parallel connected contacts RCA7 and IBTZ to the line L2. Contacts RCA8 are connected in the line L4 at a point between that where the line L4 is joined to the coil 4DA and the point Where it is joined to the coil 5DA. Contacts LCR2 are connected across the contacts RCAS. As hereinafter explained when the lift system is operating with the car A selected for rejected call service the contacts RCA7 and RCA8 are open as are the contacts IBT2. Thus no down calls can be registered for the car A via the line 1.4 since both RCA7 and IBTZ are open. When the system is operating with car A on low zone service, contacts RCA7 and RCA8 are open whereas contacts IBTZ are closed. Thus down calls can be registered via the line L4 for the coils ZDA, 3DA and 4DA. When the car A is conditioned for late car reversal the contacts RCA7, RCAS are open whereas the contacts LCR2 and IBT2 are closed. Thus down calls can be registered on the car A for all floors via the line L4.

The coils 3DA to 6DA are respectively connected through contacts 3BC3 to 6BC3 to a line L5 which is directly connected to the line L2. The contacts 3BC3 to 6BC3 are respectively associated with the third to sixth floors and each pair of these contacts becomes stresses closed by means to be described later, whenever a down call for the associated floor has been by-passed. Parallel connected contacts RCA9 and IBT3 are connected in the line L between the point at which this line is connected to the coil 4DA and the point at which it is connected to the coil 5DA. When the system is operating with car A on low zone service both the contacts IBTF; and RCA9 will be open so that lay-passed down calls cannot be registered on the car A for the fifth and sixth floors. Except when car A is on low zone service either the: contacts RCA9 are closed or the contacts IBTB are closed. The coils lUA to 6 UA that register up calls on the car A are connected through rectifiers RF to a line L6 which is directly connected to the line L2. Contacts RCAlt) are connected in the line L6 between the point where this line is connected to the coil EUA and the point where it is connected to the coil ZUA. Parallel connected contacts UIAZ and ULBI are connected across the contacts RCAlt). Unless the car A is selected for rejected call service up calls can be registered for the car A for all floors. When the car A is on rejected call service, when it is on late car reversal service and when it is on low Zone service, the contacts RCAEO are open so that no up landing calls (except from the basement) can be registered on the car A, unless the car is travelling upwardly (contacts UIA2 closed) and is a car selected to provide up service for down peak operation in which case contacts ULB7 close for a reason to be described hereinafter.

There is a circuit like that of FIGURE 4 for each of the cars B and C.

Stopping car to attend to calls registered therefor The circuitry of FIGURE 5 serves for stopping the car A at each door for which car A has to make a stop. Circuitry similar to that of FIGURE 5 is associated with each of the other cars in the system. The coil HSRA is the slow-down relay coil for the car A and whenever this coil is energised the car A is slowed down and stopped by means associated with the motor of the car A and not shown or described herein since it does not form the subject of the present invention. The coil HSRA serves for stopping the car A only at the intermediate floors. Other means (not shown) is provided for stopping the car A at the top and bottom floors. One side of the coil HSRA is connected to an earth return line ER and the other side is connected to a junction point 3P2. Switches SUZA to SU7A are respectively located at the second to seventh floors and are arranged to be closed when the car A is in the zone of the associated floor. Switches SDIA to SDGA are respectively located at the floors 1 to 6 and are each arranged to be closed when the car A is in the zone of the associated floor. I

A main line ML is connected through contacts LSRA4 operated by the load switch of the car A to a wire W1. Contacts UA4 in series with contacts DA4 are connected across the contacts LSRA4. The wire W1 is connected to one contact of the pair UAS through four parallel paths, one of which includes contacts DSRAI, the second of which includes contacts DLXAZ, the third of which in cludes contacts ULB6 and the fourth of which includes contacts RCA13. The wire W1 is also connected to one contact of the pair DAS through three parallel paths the first of which includes contacts USRAI, the second of which includes contacts ULXAZ and the third of which includes contacts DLB6.

If a car call is registered for the car A the car will stop at the floor for which the call is registered irrespective of the direction of travel. Thus say a car call is made for the fourth floor, the contacts iFAd and 41 A? are closed and when the car isin the zone of the fourth fioor the switches SUdA and SDdA are closed. Thus two circuits are completed through the coil HSRA, namely the circuit Line ML, contacts :tFA-d, switch SU4A, junction point 1P2, coil HSRA and earth return ER and the circuit Line ML, contacts 4FA7, switch SD4A, junction point 1P2, coil HSRA and earth return ER.

When the car A is travelling upwardly the contacts UAS close and provided a circuit exists between the oontacts UAS and the line ML the car A will be stopped as it comes to each successive up landing call that has been registered and will also stop at the highest down call that has been registered. Thus for an up call at say the fourth floor and provided there has been no car call registered for the fourth floor, a circuit is completed through the coil HSRA from the contacts UA5 via the closed contacts QUAZ, 4-FA3 and the switch SU4A. If a down call has been registered for the fifth floor the contacts 5DA2 will be closed and as the car moves from the fourth floor to the zone of the fifth floor the coil HSRA will become energised via the contacts SDAZ and EPA: and the switch SUSA unless a fifth floor car call has been registered for the car A (contacts SPA? will be open) and provided there is not a call registered on the car A for a floor above the fifth floor in which case one of the pairs of closed contacts 6FA2, 6UA1, 6DA1, 7FA2, AR7A1 and 7DA1 will be open.

Similarly when the car is travelling downwardly the contacts DAS are closed and provided there is a connection between the contacts DAS and the line ML the car A will stop to attend to each succeeding down call and will also stop at the lowest up call provided this is the lowest call.

After the coil HSRA is energised but before the car A has stopped at the floor to attend to the registered call, the call is cancelled and the circuit between the line ML and the point IPZ is interrupted. Whilst the car A is still moving, however, a hold circuit is completed through contacts HSRAl and either of the contacts DAG and UA6 depending upon which direction the car A is moving. When the car stops moving the coil HSRA is deenergiscd.

Up service for down peak and down service for up peak Referring to FIGURE 2, one side of the coil ULXA is connected to a negative line N1 and the other side is connected to a junction point TF3. The point 1P3 is connected through three parallel paths to a point J P4 which is connected through contacts ULA3 to a positive line PL. The first of the three paths includes contacts ULB4, the second includes contacts ULC; and the third includes contacts ULXAI. If the system is operating on down peak and the car A becomes the first car to travel upwardly with its load switch operated, the coil ULA becomes energised and the contacts ULA3 close. As neither of the coils ULB and ULC is energised at this stage, the coil ULXA becomes energised and closes its associated contacts ULXAIt whereby a holding circuit is completed for the coil ULXA. The coils ULXB and ULXC associated with the cars B and C are connected in a way that is similar to the coil ULXA for the car A. The coils DLXA, DLXB and DLXC are connected to operate similarly for downward travel of the cars A, B and C.

For the system to be operating on down peak, the cars A, B and C will within two minutes (the delay of the timer TY) of each other have been travelling downwardly with their load switches operated and the coils DLA, DLB and DLC will be energised as will the coil DSR to establish down peak operation. If it is assumed that car A was the first to become loaded and car B the second, closure of contacts DLA3 will have energised the coil DLXA and closure of the cor. Lacts DLBS will have energised the coil DLXE. Subsequent loading of the car C causes the contacts DLC3 to close but as at this time the contacts DLBS and DLAS are open the coil DLXC does not become energised. Referring now to FIGURE 5, the establishment of down peak opens the contacts DSRAI and the energisation of the coil DLXA opens the contacts DLXA2. None of the cars at this time are travelling upwardly with their load switches operated so that the contacts ULB6 are open. Assuming rejected call service has not been established, the contacts RCA13 will be open. Thus no closed circuit can be established between the contacts UA and the line ML, so that the car A when travelling upwardly (contacts DA5 open and contacts UA5 closed) cannot be stopped to answer a floor call. In the circuit corresponding to FIGURE 5 for car B, the contacts DSRBI, DLXBZZ, ULC6 and RCB13 will all be open so that car B also cannot stop to attend to floor calls whilst travelling upwardly. In the circuit for the car C that corresponds to FIGURE 5 the contacts DSRCl will be open as will the contacts ULA6 and RCC13 but the contacts DLXCZ will be closed so that the car C is the only one to attend to floor calls whilst travelling upwardly. Since the system is on down peak the car C will be autoreturned to the top floor and as an upwardly travelling car goes to the highest call before reversing to deal with down calls, in effect car C, in the circumstances mentioned, becomes the car serving up calls whilst the system is on down peak.

Assume now that with the system operating as just described, the tratfic in the up direction increases such that the load switch in the car C closes whilst the car is travelling upwardly, the coil ULC becomes energised and the contacts ULC6 in the circuit corresponding to FIGURE 5 for the car B are closed so that the car B is conditioned to attend to up calls in addition to the car C. If both cars B and C whilst travelling upwardly become sufficiently loaded for their load switches to be operated, then both coils ULC and ULB are energised and the contacts ULC6 and ULB6 are closed whereby both cars A and B assist car C in attending to up calls.

Once additional cars have been allocated for dealing with up calls they remain allocated for that service until the load in all upwardly travelling cars has become less than the preset load to operate the load switches and the preset time on the timer TX has expired. When this occurs the system reverts to one car for up service.

Upon energisation of the coil USR (to establish up peak), the system provides down service for up peak operation in a similar way to that described of providing up service for down peak operation except that the directions are reversed. Thus upon the initial establishment of up peak, just one car attends to down calls. As the down trafiic increases (judged by the load in the car taking down calls) a second car is allocated for dealing with down calls and upon further increase in down trafiic all three cars attend to down calls.

It will be noted that when the system is on down peak operation, extra'cars are allocated to deal with increase in up traffic and that even though all cars may become allocated for up traffic, despatching still takes place from the upper terminal as down peak operation was the prior setting and the contacts DSRl will be open to prevent the coil USR from becoming energised. If, however, the down peak subsides whilst the cars are still being suflicien ly loaded in the up direction to close their load switches, the system upon de-energisation of the coil DSR will change to up'peak operation (the coil USR becomesenergised) and despatching commences from the main floor. Similar- 1y, when the system is on up peak operation and extra cars become allocated to deal with increase in down traffic despatching continues to take place from the main floor even though all the cars become loaded for the down direction since the contacts USRI prevent the coil DSR from becoming energised. Upon the up peak subsiding without corresponding subsidence of down traflic, the coil USR becomes de-energised, the contacts USR close and p the coil DSR is energised to establish down peak and despatching from the upper terminal.

, Reiected call service When a downwardly travelling car, say the car A,

becomes sufiiciently loaded to close its. load switch the contacts LSRA4 open so thatthere is no connection between the line ML and the wire W1 whilst the car is in motion. Thus the car does not stop to attend to any down landing calls. If the loaded condition of downwardly travelling cars repeatedly occurs near the top of the hatchway, down floor calls at floors lower down the hatchway will be repeatedly by-passed. The rejected call service is provided for dealing with this situation.

Referring to FIGURE 2, the line PL is joined to a wire W2 through contacts DSR2. A wire WA3 is connected to the wire W2 through a rectifier RF, contacts DA3 and contacts LSRA3. A wire WB3 i connected to the wire W2 through a rectifier RF, contacts DB3 and contacts LSRB3. A wire WC3 is connected to the Wire W2 through a rectifier RF, contacts DC3 and contacts LSRC3. Bypass relay coils 3BC to 6BC are provided for the floors 3 to 6 respectively. A capacitative circuit is connected in parallel with each of these coils so that the coils operate their associated contacts immediately upon energisation thereof but upon deenergisation there is a time delay of some ten to fifteen seconds before the associated contacts are re-operated. One side of the coil 6BC is connected to the line N1 and the other side is connected to the wire WA3 through contacts L6D1 and a switch ,S6A which is closed only when the car A is in the zone of the sixth floor. Said other side of the coil 6BC is connected to the wire WB3 through contacts L6D1 and a switch 86B which is closed only-when the car B is in the zone of the sixth floor. Said other side of the coil 6BC is connected to the wire WC3 through contacts L6D1 and a switch 86C which is closed only when the car C is in the zone of the sixth floor. Said other side of the coil 6BC is also connected to the wire W2 through contacts 6BC1. The contacts L6D1 close whenever there is a landing call outstanding at the sixth floor. When the system is on down peak the contacts DSR2 are closed and Whenever a car, say the car A, is travelling downwardly (DA3 closed) with its load switch operated (LSRA3 closed) and is in the zone of the sixth floor (switch 86A closes) for which there is a landing call outstanding (contacts L6D1 closed), the coil 6BC is energised whereby the contacts 6BC1 close. Closure of the contacts 6BC1 establishes a holding circuit for the coil 6BC and the coil will remain energised until the landing call is attended to or the down peak subsides. The coils 3 BC to SBC are arranged to operate similarly to the coil 6BC but for the floors 3 to 5 respectively.

One side of the rejected call relay coil IBT is connected to a junction point IPS and the other side of this coil is connected to the anode A of a valve V3 of the timer TW, the cathode K of the valve V3 being connected to the line N1. The point JPS is connected to a point 1P6 through four parallel paths and the point J P6 is connected to the wire W2 through contacts XBTL' The four parallel paths respectively comprise contacts 3BC2 to 6BC2 controlled respectively by the coils 3BC to 6BC. The valve .V3 is connected in such a way that when positive potential is applied to the anode from the line PL the valve does not commence conducting until some sixty seconds after the potential has been applied to the anode. Thus assuming contacts XBTl to be closed the coil IBT will not become energised un il some sixty seconds after one of the by-pass coils 373C to 6BC has become energised.

The wire W2 is connected to a wire W3 through parallel connected contacts IBTl, LCR1 and XBT2. One side of the coil RCA is connected to the line N1 and the other side is connected through series connected contacts DLXA, RCCI, RCBl and TPAl to a junction point JPS. The point JPS is connected through contacts UA3 and a switch S2A1 to the wire W3. The switch S2A1 is closed only when the car A is at the main floor. Contacts RCA3 are connected across the contacts UA3 and switch S2A1. The contacts TPAl just mentioned, open when the car A has remained stationary at a floor other than the despatching floor 'for more than a predetermined time limit. The

1 1 operation of the coil TPA that controls the contacts TPAI is described in Patent No. 2,847,090. The coils R'CB for the car B and RCC for the car C are connected between the wire W3 and the line N1 in a manner similar to the coil RCA.

When the system is operating on down peak and a down landing call at say the fifth floor is by-passed by a loaded downwardly travelling car energisation of the coil SBC persists so that the contacts SBCZ remain closed. After the predetermined time interval (determined by the timer TW) rejected call service is signalled by the coil IBT operating its associated contacts. Thus the contacts IBTl close and positive potential is applied to the wire W3. For down peak operation two of the three pairs of contacts DLXA3, DLXB3, DLXC3 will be closed, the third pair, that corresponding to the car providing up service, remaining open. Assume the car C is the one providing up service so that the contacts DLXC3 are open. Thus coil RCC cannot be energised. The first of the cars not allocated for up service (i.e. the first of cars A and B) to reach the main floor and become set on an up trip will be selected for rejected call service by energisation of its associated coil RCA or RG3 as the case may he. Assume car A is the car in question. When this car reaches the main floor and becomes set on an up trip, the switch S2A1 is closed and the contacts UA3 are closed. The contacts DLXA3 are already closed, as are all the other contacts between the point IRS and the coil RCA. Thus the coil RCA is energised closing its holding contacts RCA3 so that the coil remains energised after the car A has departed from the main floor. Once the car A has become selected for rejected call Service, the cars B and C cannot become so selected since the contacts R-CAI in series with the coil RCB and the contacts RCA2 in series with the coil RCC are opened.

Referring now to FIGURE 4, when the car A is selected for rejected call service the contacts RCA7 and IBTZ are open so that the connection between the line L4 and L2 is broken. Contacts RCA9 are open and contacts IBT3 are closed so that the whole of line L5 is directly connected to the line L2. Contacts RCAIO are open and contacts ULB7 are open (since it is assumed that, at this stage, car C is the only one attending to up fioor calls). Thus only the part of the line L6 that is associated with up floor calls below. the main floor is connected to the line L2. The line L4 is that appropriate to non-by-passed down calls, the line L5 is that appropriate to by-passed down calls and the line L6 is that appropriate to up calls. Thus apart from a basement call, the only calls that can be registered on the car A are by-passed down floor calls. Although the system is on down peak operation, the car A is prevented from being autoreturned to the seventh floor by the opening of the contacts RCA6 in series with the coil AR7A (FIG- URE 3). Assuming the highest by-passed down floor call to be that at the fifth floor, contacts 5B'C3 will be closed as will the contacts LSDAI and the coil SDA will be energised. This fifth floor call will be the highest call remaining registered on the direction selector (not shown) of the car A and on the circuitry of FIGURE 5 (contacts SDAZ closed). Thus the car A will travel to and stop at the fifth floor, the circuit between the contacts UAS and the wire W1 being completed through the now closed contacts RCA13. Upon arrival at this floor the fifth fioor call will be cancelled so that the contacts LSD]. open to de-energise the coil SBC and the contacts LSDAi open to de-enengise the coil 'SDA. Upon arrival of the car at the tloor the up direction that was selected on the direction selector drops off and the car remains (for reasons to be described later) for a predetermined time with no direction selected therefor and is thus available for downward travel. If no down travel is selected within the predetermined time by a car call or a landing call the car is auto-returned to the top floor which is the despatching 'fioor. Such auto-returning follows upon de-energisation of the coil 58C. A predetermined time after the circuitry of this coil is interrupted, the contacts 5BC2 open whereby the coil IE1 is de-energised and its contacts immediately revert to their initial position so that coil RCA is de-energised by opening of the contacts IBTJL. Deenergisation of the coil RCA closes the contacts lBTl. Deenergisation of the coil RCA closes the contacts R-CA6 and the coil AR7A is energised whereby a call for a top floor is registered in the direction selector. It will be understood therefore that the time for which the car A remains available at the fifth floor for downward travel is determined by the delay between opening of the circuit through the coil SBC and the time at which the contacts SBCZ open.

When the car A reverses at the highest by-passed call, it then answer-s any other by-passed down floor calls below it, but cannot at this stage answer non-by-passed down floor calls since whilst there is still a hy-passed call outstanding the contacts RCA7 and IBTZ are still open and line L4 is not connected to line L2. After the last bypassed call has been answered the car can then respond to any down calls below it (as contacts RCA7 and IBT2 become closed) until the car becomes fully loaded (LSRA4 open to prevent stopping in answer to floor calls).

Should the car on rejected call service, say the car A, be driven by a car call beyond the highest by-passed call, it attends to the car call and as the highest by-passcd call is then the nearest call registered on car A and on the direction selector for car A, the car reverses at the highest car call and then proceeds directly to the highest bypassed call.

The rejected call service remains in operation until no further rejected calls remain (all of coils SEC to 68C and thus also coil IBT de-energised) or until the system changes to zone control.

The coils TBU and TBD (FIGURE 6) are each of the kind that operates its associated contacts immediately a circuit is completed through the coil but upon the circuit being broken there is a delay before the contacts resume their initial condition. Switch S2A4 is located at the main floor and is open only when the car A is at the main floor. Switch SZAS is also located at the main floor and is closed only when the car A is at the main fioor. When the car A is on an upward trip the contacts URAI are closed and the coil TBU is energised so that the contacts TBUI are closed. The coil LDA cannot at this time be energised as the contacts URA2 are open. The coils LUA and LDA exercise control over the direction selector of the car A and the indicator system for the car A in the manner described in Patent No. 2,847,090. When the car A is not selected for rejected call service, the contacts RCAH are closed and the contacts RCAIZ are open so that the coils LUA and LDA operate normally. When the car A is selected for rejected call service, the contacts RCAII open, so that during upward travel of the car A, although contacts TBUI and DRAZ are closed the coil LUA is not energised. The switch S2A4 is closed as are the contacts RCAIZ and the coil LDA is placed in a condition for energisation depending upon closure of the contacts URA2. When the car A arrives at the floor of the rejected call and stops there the contacts URA2 close immediately so that the coil LDA is immediately energised. This causes the down lantern at the floor of the rejected call Where the car has stopped to become illuminated and to remain illuminated as long as the contacts RCA12 are closed. If during this period the car becomes set for downward travel the contacts DRAl close and the coil TBD is energised so that the contacts TBDl close and maintain the coil LDA energised. On the other hand, if during the time that the car A remains at the fioor of the rejected call no car call or floor call becomes registered on the car A during the period that coil RCA is energised, upon this coil becoming de-energised the coil 13 LDA will also become de-energised. Following de-energisation of the coil RCA an auto-return call for the seventh floor is registered on the direction selector of the car A so that the direction selector causes contacts URAl to close whereby the coil TBU is energised, the contacts TBUI are closed and as the contacts RCA11 are now closed the coil LUA is energised and the up lantern is illuminated at the floor at which the car A is standing.

Zone control If during rejected call service calls at lower floors are still repeatedly by-passed the system switches to zone control. To this end the floors are divided into upper and lower zones, the dividing line between the two zones being arbitrarily selected and in the present example being between the fourth and fifth floors. When on zone control certain cars, in the present described embodiment just one car, serve primarily the lower zone.

One side of the zoning relaycoil XBT (FIGURE 2) is connected to the anode A of a valve V4 of the timer T2, the cathode K of which is connected to the line N1. The valve V4 is arranged so that when the positive potential of the line PL is applied to the anode A, the valve V4 does not conduct and cause the coil XBT to operate its associated contacts until a time interval of some sixty seconds. The other side of the coil XBT is connected to a junction point JP6 which is connected by parallel connected contacts 3BC4 and 4BC4 to a wire W4. The wire W4 is connected through parallel connected contacts RCA4, RCB4 and RCC4 to a junction point JP7 that is connected to the wire W2. The junction point 1P6 is also connected to the junction point JP7 through contacts XBT3 that are connected in series with parallel connected contacts L4D2 and L3D2. The predetermined time interval of the timer T2 is controlled by an R-C circuit that includes contacts 3BC5 and 4BC5. Closure of one of these two pairs of contacts reduces the time interval of the timer TZ by a first predetermined amount and closure of both pairs simultaneously reduces the time interval by a second predetermined amount. Cathode heating current for the valves V3 and V4 is provided from the secondary winding S2 of a transformer T1 the primary coil P2 of which is connected to an alternating current supply, I

The zoning relay coil XBT controls contacts XBTAI (FIGURE 3) and similar contacts of the car call circuits of the cars B and C for causing continuous registration of a main floor call for the car selected for zone control, as described above. Coil XBT also controls contacts XBTZwhich are connected between the wire W2 and the wire W3. If a down floor call in the lower zone and above the main floor is bypassed by a loaded downwardly travelling car the contacts 3804 or 4BC4 as the case may be, are closed.' If the by-passed call remains unanswered rejected call service is eventually signalled by energisation. of the coil IBT and this causes, as described above, one of the cars to be selected for rejected call service through energisation of coil RCA or RCB or RG0. Say the car A is selected for rejected call service so that the coilRCA is theone that, is energised. The contacts RCA4 close so that a circuit is completed through the coil XBT and the valve V4. After the predetermined time interval of the timer T2 the coil XBT operates its contacts. Contacts XBTI open so that the coil IBT is de-e nergised. The contacts XBT2 close so that the coil RCA remains energised inspite of the opening of the contacts IBTl consequent upon de-ene'rgisation of thecoil IBT. The contacts RCA7 (FIGURE '4) are now open whilst the contacts IBTZ are closed. The contacts RCA8;,-RCA9 and IBT3 are all open so that no down calls (by-passed or normal) can be registered on the car .A for floors above the fourth floor. Contacts RCA10 are open. Provided thecar A has not been selected to 1 providefiup service'additional to one of the other cars the contacts ULB7 are open. In these circumstances no up calls can be registered on the car A for floors above the main floor. Thus as far as floor calls are concerned the car A serves down calls registered for the fourth floor downwards. A main floor car call is in continuous registration for the car A so that the car A is limited primarily to operating in the lower zone.

Once zoning is signalled, i.e. once the coil XBT is energised, the contacts XBT3 are closed and if there is a down landing call in the lower zone contacts L3D2 or L4D2 or both of them will be closed so that the coil XBT will remain energised until there are no more down calls in the low zone.

The low zone car (say the car A), travels to the highest floor call in the low zone and this is not necessarily the highest by-passed call since if there is say a by-passed call at the fifth floor it cannot be registered on the car A because the contacts IBT3 and RCA9 are open. The car reverses at the highest floor call in the low zone and stops at all down calls below it unless it becomes loaded sufiiciently to operate the load switch in which case the contacts LSRA4 open to prevent the car A stopping in response to floor calls.

With the three-car system herein exemplified there will during zone control ordinarily be a first car operating primarily in the low zone, a second car operating in both the low and high zones and giving up floor call service to all floors, and a third car operating in both zones but giving no up fioor call service at any of the floors. If the car allocated for up floor call service becomes loaded and thus a further car is allocated for assisting in dealing with up calls, the operation is as follows:

(a) If the low zone car is allocated it serves the highest car call or up call (contacts UIA2 and ULB7 are closed, assuming the car in question to be car A) in the high zone, there reverses (contacts UIAZ becoming open) and after clearing outstanding car calls between the reversing floor and the highest down call inthe low zone proceeds directly to the highest down call in the low zone and thereafter takes all down calls below until loaded (contacts LSRA4 open and prevent stopping in response to floor calls).

(b) If the car serving in both zones but which was not formerly serving up floor calls is now allocated for this service it operates in the same way as the other car serving the high zone and the low zone.

When the low zone car is driven into the high zone by a car call it responds to car calls only in the high zone and after clearing these expresses to the highest down call in the low zone.

Whilst the system is operating on zone control, if all that is maintaining the system on zone control is one bypassed call in the lower zone the registration of a land ing call for the floor of the by-passed call just after the by-passed call is served will maintain the system on zone control. This is so as the system does not discontinue zone control immediately the by-passed call is served since there is a time delay in the operation of the contacts of the coils BBC and 413C. If following the serving of the by-passed call a landing call is re-registered for the same floor, say the fourth floor, before the contacts 4BC1 and 4BC4 have opened, the coil 4BC will be reenergised through the contacts 4BC1 and L4D1 so that zone control will be maintained through the contacts 4 04 and one of the pairs of contacts RCA4. RCB4 and RCC4.

Late car reversal One side of the coil LCR (FIGURE 2) is connected to the line N1 and the other side is connected through contacts CR1, BR1, ARI, XBT4 and IBT4 to the line W2 which is connected through the contacts DSR2 to the positive line PL. Contacts MRAl are connected across contacts ARI, contacts MRBI are connected across the contacts BRI and contacts MRCI are connected across the contacts CR1. The contacts AR1 are controlled by the coil AR, the contacts BRl by the coil BR and the contacts CR1 by the coil CR. The operation of these three coils is described in detail in Patent No. 2,847,090. Sufiice it to say that when the despatch interval has expired on the car A the contacts ARI are closed, when it has expired on the car 13 the contacts BRI are closed and when it has expired on the car C the contacts CR1 are closed. If all three cars are away from the despatching floor and the despatch interval for the next car to be despatched from the despatching floor has expired then all three coils are energised and the pairs of contacts ARI, BRI and CR1 will be closed. When the system is on downward despatch (contacts DSR2 closed), rejected call service is not in operation (contacts IBT4 closed), zone control is not in operation (contacts XBT4 closed), the despatching interval for the next car to be despatched from the upper terminal has expired and all three cars are away from the despatching floor (contacts ARI, BRl,

CR1 are closed), the coil LCR will be energised. Upon energization of this coil the contacts LCRI close so that the wire W3 is connected to the positive line PL. The first car to be driven away upwardly from the main floor (other than the car giving up fioor call service) will have its rejected call relay coil RCA, RCB or RCC as the case may be, energised. In these circumstances the whole of line L4 (FIGURE 4) is connected to the line L2 since the contacts IBTZ are closed as are the contacts LCR2. As the contacts RCA (FIGURE 3) are open the car A is not auto-returned to the top floor. Instead it stops at the highest car or down landing call and there reverses in a manner similar. to that described in connection with the rejected call service. If late car reversal service is in operation and either rejected call service or zone control is signalled, late car reversal is cancelled by the opening of the contacts IBT4 or XBT4 in the circuit of the coil LCR and then the system operates on rejected call or on zone control as previously described. The contacts MRAI, MRBI and MRCl are maintenance contacts which become closed when the cars A, B and C respectively are taken out of service for maintenance purposes. Thus late car reversal can still operate on the remaining cars even though one car is taken out of service for maintenance purposes.

When one car is operating on late car reversal service, this service is only effective until another car has returned to the upper terminal floor. Thus if a car, say car A, has been selected for late car reversal and has not yet reached its highest car call or down floor call when another car, say car C, arrives back at the top floor, the coils AR and ER will be de-energised so that the contacts ART and BRl will open thereby causing the coil LCR to be de-energised so that the late car reversal service is cancelled and the car A formerly selected for late car reversal also returns to the upper terminal floor. Rejected call service or zone control always overrides late car reversal service and becomes effective upon the car already selected for late car reversal.

Prevention of rte-registration of car calls When the system is operating on down peak it is desirable to prevent persons who are leaving the car at the main floor from re-registering a car call to cause the car to stop during its next upward journey at a floor at which the person knows a friend to be waiting. If this were done it would interfere with the efliciency of the system. Means are therefore provided for cancelling car calls when, on down peak operation, a car nears the main floor andlfor preventing registration of car calls for a predeter- When the system is not on down peak operation, the self-101d circuit for the relay coils ZFA to 7FA for the car A remain unaffected because of the normally closed contacts DSR4. When, however, the system is on down peak, contacts DSR4 are open and the contacts DSRS are closed. The self-hold circuits of the coils ZFA to 7FA become closed through the switch SZAZ or through the contact UIAI or through the switch S2A3 and the contacts LDAI. The switch S2A2 is open when the car is at or near the main floor and is closed when the car is away from the main floor. Thus when the car is not at the main floor the self-hold circuits can be completed through the switch SZAZ. The contacts UlAl close when the car A is selected for an up trip. When the car A arrives downwardly at the main floor and is not conditioned to proceed to the basement, contacts DRAI (FIG- URE 6) open and the circuit through the coil TED is opened. There is a time delay before the contacts TED open. When the contacts TBDI do open the coil LDA is de-energised and the contacts LDAI close. The switch S2A3 is closed when the car A is at the main floor. Thus when the car A arrives at the main floor the switch SZAZ is opened, the contacts UIAl are open and the contacts LDAl are open so that all the self-hold circuits for the coils 2FA to 7FA are broken and all the car calls are cancelled. After a predetermined time interval the contacts TBDI open whereby the contacts LDAI close and car calls can then be registered and will remain registered on the coils ZFA to 7FA via the contacts DSR5, LDA1 and the switch S2A3. In the event that the car A makes a trip to the basement and car calls are registered at the basement for fioors above the main floor these calls will remain registered when the car arrives at the main floor since when the car leaves the basement it is selected for an upward trip and the contacts UIAI remain closed during the upward trip. Thus in this case car calls are not cancelled when the car approaches the main floor.

In a modified version of the lift system described with reference to FIGURES 1 to 6, the signalling of rejected call service is not made dependent upon the system being switched to down peak. To this end the contacts DSRZ of FIGURE 2 are omitted, contacts DSRS (FIG- URE 8) being inserted in series with the zoning relay coil XBT and contacts DSR9 being inserted in series with the late car reversal relay coil LCR. Thus zoning service and late car reversal service cannot be put in operation unless the lift system is operating on down peak. The contacts DLXA3 remain in series with the coil RCA but are shifted as compared with the FIGURE 2 arrangement so that they are bridged by the contacts RCAS. The contacts DLXB3 and DLXC3 are similarly displaced. This shifting of the contacts DLXA3, DLXBB and DLXC3 enables the rejected call service to self-hold until all rejected calls have been attended to, irrespective of the loading of the rejected call car.

It would be unusual for a car operating on rejected call service to become sufficiently loaded Whilst collecting a rejected down call for its load switch to operate. However, heavy down trafiic conditions may arise whilst a car is on rejected call service and thus to enable the system to switch to down peak whilst a car is on rejected call service, contacts RCA14 (FIGURE 7), RCBM and RCC14 are respectively connected across the contacts DLA2, DLBZ and DLCZ in the circuit of the coil DSR.

In the circuit shown in FIGURE 8, an auxiliary circuit is connected across the zoning relay coil XBT and the timer TZ. This auxiliary circuit includes an auxiliary zoning relay coil XBTX one side of which is connected to the line N1. The other side of this coil is joined to a junction point JPS which is connected through four parallel paths to a junction point TF9. The point W9 is connected through contacts XBTS to tie positive side of the coil XBT. The first of the four paraliel paths consists of series-connected contacts RCAlS and UA7. The second path consists'of series-connected contacts RCBRS and UB7 and the third path consists of series-connected contacts RCC and UC7. The fourth path consists of contacts XBTXl. The contacts XBTl, XBT2 and XBT4 of FIGURE 2 are replaced by contacts XBTXZ, XBTX3 and XBTX4. The arrangement just described prevents the rejected call car being switched to Zoning service whilst the car is travelling upwardly to collect a by-passed call. Thus assume the car A is operating on rejected call service, the contacts RCAIS will be closed and the contacts UA7 will be open. If the timer TZ times out whilst the car is travelling upwardly, the contacts XBTS will close but the coil XBTX cannot become energised until the car has stopped because the contacts UA7 are open. When the car stops at the floor of the by-passed call the contacts UA7 close and the coil XBTX is energised whereby zoning service is put into operation. Immediately the coil XBTX is energised the contacts XBTXl close to es tablish a holding circuit for the coil XBTX. When the rejected callcar leaves the floor of the by-passed call the car proceeds directly to the highest down call in the low zone.

The contacts MRA2, MRBZ, MRCZ, MRA3, MRB3 and MRC3 (FIGURE 7) are maintenance contacts which become closed when the associated ones of the cars A, B and C are taken out of service for maintenance purposes. Thus if the car A is taken out of service the contacts MRA2 and MRA3 close. The switching of the system to up peak and down peak is then dependent upon operation of the contacts ULBZ, ULCZ, DLBZ and DLCZ, the contacts ULAZ and DLAZ being ineffective.

For maintenance purposes it may be desirable to insert closed maintenance contacts (not shown) in series with the contacts ARAI (FIGURE 3), so that the car on maintenance service cannot have a car call for the main floor registered thereon as a result of being driven away from the main floor.

If desired the rectifiers RF shown at the top of FIGURE 7 2 may be omitted. The rectifiers RF in FIGURE 4 may also be omitted and replaced by contacts 3BC6 to 6805 (FIGURE 9) connected respectively between the line L4 and the coils 3DA to 6DA.

In an improved form of the circuit of FIGURE 5, the contacts HSRAI are replaced by contacts HSRAZ and HSRA3 (FIGURE 10) and the contacts UA6 and DA6 are repositioned as indicated in FIGURE 10.

I claim:

1. A lift system in which a plurality of cars serve a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means for each carfor causing the car when travelling down and when a certain condition exists to bypass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting a car to travel upwardly to stop at the floor of a by-passed down floor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time. after a down floor call is by-passed, and means for causing the selected car to proceed first to the highest bypassed down floor call irrespective of whether said highest call initiated operation of said rejected call means.

2. A lift system in which a plurality of cars serve a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means in each car for registering car calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are bypassed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time after a down floor call is by-passed, and means for causing the selected car to attend to successively higher car calls 18 that have been registered and then to proceed from the highest car call to the highest by-passe'd down floor call.

3. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with tratlic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic and an up peak mode of operation suitablefor heavy up traffic, means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, and means for preventing operation of said rejected call means unless the system is operating on down peak.

4. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with traffic conditions, the modes including a down peak mode of operation suitable for heavy down traflic and an up peak mode of operation suitable for heavy up traffic, means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down fioor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time after a 'down floor call is by-passed, and means for preventing operation of said rejected call means unless the system is operating on down peak.

5. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with tratfic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic, and an up peak mode of operation suitable for heavy up traflic, and a normal mode of operation suitable for balanced traffic conditions, means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down fioor calls that are bypassed, and rejected call means for selecting, irrespective of the mode of operation of the system, an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto.

6. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with traffic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic, and an up peak mode of operation suitable for heavy up trafiic, and a normal mode of operation suitable for balanced trafiic conditions, means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting, irrespective of the mode of operation of the system, an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, and timing means for initiating operation of said rejected call means a predetermined time after a down floor call is by-passed.

7. A lift system in which a pluralityof cars serve'a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering aeeasee EQ down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, and means for preventing the selected car from attending to non-by-tpassed down floor calls until all by-passed down floor calls have been dealt with.

8. A lift system in which a plurality of cars serve a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a bypassed doWn fioor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time after a down floor call is by-passed, and means for preventing the selected car from attending to non-by-passed down floor calls until all by-passed down floor calls have been dealt with.

9. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic and in which cars are despatched from the upper terminal floor, means for returning each car, when the system is on down peak, to the upper terminal floor upon completion of a trip, means at the intermediate floors for registering up and down floor calls, means in each car for registering car calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass registered down fioor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, means for rendering the returning means ineffective on a selected car, up and down lanterns at the floors for indicating the direction in which a car stopping at the floor will depart from the floor, means for cancelling a call registered at any floor when a car stops at the floor to attend to the registered floor call, and means, when a selected car stops at the fioor of a by-passed down floor call to attend thereto, for illuminating the down lantern at the floor for a predetermined time interval subsequent to which, if no call exists to cause the car to proceed downwardly, the returning means can become eifective on the car to cause the down lantern to be extinguished, the up lantern to be illuminated and the car to leave the floor upwardly.

10. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with traffic conditions, the modes including a down peak mode of operation suitable for heavy down tratlic and an up peak mode of operation suitable for heavy up traffic, means at the intermediate floors for registering up and down floor calls, first means for causing upwardly travelling cars to by-pass up floor calls when the system is on down peak, second means for causing downwardly travelling cars to by-pass down floor calls when the system is on up peak, means preventing the first causing means from being elfective on at least one of the cars so that this car can serve up floor calls whilst the system is on down peak, and means for preventing the second causing means from being effective on at least one of the cars so that this car can serve down floor calls whilst the system is on up peak.

11. A lift system in which a plurality of cars serve a number of floors, the system comprising means for selecting the mode of operation of the cars in accordance with traffic conditions,the modes including a down peak mode of operation suitable for heavy down trafiic and an up peak mode of operation suitable for heavy up traffic, means at the intermediate floors for registering up and down landing calls, first means for causing upwardly travelling cars to by-pass up floor calls when the system is on down peak, second means for causing downwardly travelling cars to by-pass down floor calls when the system is on up peak, means preventing the first causing means from being effective on at least one of the cars so that this car can serve up floor calls whilst the system is on down peak, means for preventing the second causing means from being effective on at least one of the cars so that this car can serve down floor calls whilst the system is on up peak, means for each car for causing the car when travelling down and when a certain condition exists to bypass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, and means for preventing the rejected call means from selecting, for attending to a by-passed down floor call, said one car that serves up floor calls whilst the system is on down peak.

12. A lift system in which a plurality of cars serve a number of floors, the system comprising means for operating the cars in a down peak mode which is suitable for heavy down trafiic, means for operating the cars in an up peak mode which is suitable for heavy up traific, means at the intermediate floors for registering up and down floor calls, first means for causing upwardly travelling cars to by-pass up floor calls when the system is on down peak, second means for causing downwardly travelling cars to by-pass down floor calls when the system is on up peak, means preventing the first causing means from being effective on at least one of the cars so that this car can serve up floor calls whilst the system is on down peak, means for preventing the second causing means from being effective on at least one of the cars so that this car can serve down floor calls whilst the system is on up peak, load-responsive means in each car for operating when the load in the associated car exceeds a predetermined amount, means for selecting the down peak mode when within a predetermined time interval of each other all the cars when travelling downwardly have their load-responsive means operated, means for selecting the up peak mode when within a predetermined time interval of each other all the cars when travelling upwardly have their load-responsive means operated, means for causing said one car that serves up floor calls whilst the system is on down peak to be the last car of the cars in the system that became a downwardly travelling car on which the load-responsive means is operated, and means for causing said one car that serves down floor calls when the system is on up peak to be the last car of the cars in the system that became an upwardly travelling car upon which the load-responsive means is operated.

13. A system as claimed in claim 12, and further comprising means for causing another car to attend to up floor calls with the system on down peak when the load-responsive means has operated on said one car that serves up floor calls whilst the system is on down peak, and means for causing another car to attend to down fioor calls with the system on up peak when the loadresponsive means has operated on said one car that serves down floor calls whilst the system is on up peak.

14. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a low zone and a high zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down lioor call to attend thereto, and zoning means for causing the selected car to be unresponsive to floor calls registered for high zone floors when a by- 21 passed down floor call for a low zone floor has persisted for more than a certain time following the commencethem of operation of said rejected call means whereby the selected car becomes a low zone car.

15. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a low zone and a high zone; the system comprising means at the intermediate floors for registering up and downfloor calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time after a down floor call is by-passed, and zoning means for causing the selected car to be unresponsive to floor calls registered for high zone floors when a by-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby the selected car becomes a low zone car.

16. A liftsystem in which a plurality of cars serve a number of floors, the floors being divided into a low zone and a high zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, zoning means for causing the selected car to be unresponsive to floor calls registered for high zone floors when a by-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby theselected car becomes a low zone car, and means for reducing said certain time as the number of by-passed down floor calls for the low zone floors increases.

17. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a low zone and a high zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of the highest. by-passed down floor call to attend thereto and then to proceed downwardly and attend to successively lower by-passed down floor calls, zoning means for causing the selected car to be unresponsive to floor calls registered for high zone floors when a. by-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby the selected car becomes a low zone car, and means for causing the low zone car to attend to up low zone floor calls and down low zone fio'or calls irrespective of whether such down calls have been by-passed.

18. A lift system in which'a plurality of cars serve a number of floors, said landingsbeing divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, means in each car for registering car calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor. call to attend thereto, zoning means 'for causing the selected car to be unresponsive to floor calls registered for high zone floors when a by-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby the selected car becomes a low zone car, and means for causing the low zone car when a car call is registered in this car for the high zone to attend to the car call and then proceed to the highest down floor call in the low zone.

19. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, zoning means for selecting a car for low zone service following the bypassing of a low zone down fioor call, and means for causing the low zone car to remain on low zone service when all by-passed down floor calls in the low zone have been attended to whenever there is still a non-bypassed down floor call registered for a low zone floor.

20. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass registered down fioor calls, means for registering down floor calls that are by-passed, zoning means for selecting a car for low zone service following the bypassing of a low zone down floor call, means for maintaining the zoning means effective for a predetermined period following the arrival of a car at the floor of the last remaining down floor call in the low zone to attend to this call, and means for causing a down low zone floor call registered in said predetermined period to maintain said zoning means in operation until this floor call is attended 21. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, zoning means for selecting a car for low zone service when a low zone down floor call acquires a certain time characteristic, means for maintaining the zoning means effective for a predetermined period following the arrival of a car at the floor of the last remaining down floor call in the low Zone to attend to this call, and means for causing a down low Zone floor call registered in said predetermined period to maintain said zoning means in operation until this floor call is attended to.

22. A lift system in which a plurality of cars serve a number of floors, the fioorsbeing divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certaincondition exists to bypass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereto, zoning means for causing the car selected by the rejected call means to be unresponsive to floor calls registered for high zone fioors when a by-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby the selected car becomes a low zone car, and means for preventing the zoning means from becoming effective whilst the selected car is travelling upwardly to attend to a by-passed down floor call.

23. A lift system in which a pluralitv of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor aoaasea calls, means for each car for causing the car when travelling down and when a certain condition exists to bypass registered do-wn floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the door of a by-passed down floor call to attend thereto, timing means for initiating operation of said rejected call means a predetermined time after a down floor call is lay-passed, zoning means for causing the car selected by the rejected call means to be unresponsive to floor calls registered for high zone floors when a lay-passed down floor call for a low zone floor has persisted for more than a certain time following the commencement of operation of said rejected call means whereby the selected car becomes a low zone car, and means for preventing the zoning means from becoming effective whilst the selected car is travelling upwardly to attend. to a by-passed down floor call.

24. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic and an up peak mode of operation suitable for heavy up trafiic, means at the intermediate floors for registering up and down fioor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down floor call to attend thereo, zoning means for selecting a car for service in the low zone, and means for preventing operation of the rejected call means and the zoning means unless the system is operating on down peak.

25. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic and an up peak mode of operation suitable for heavy up trailic, means at the intermediate floors for registering up and down floor calls, means for causing an upwardly travelling car to stop at the floor of a down floor call that has acquired a predetermined time characteristic to attend thereto, zoning means for selecting a car for service in the low zone, and means for preventing operation of the causing means and the zoning means unless the system is operating on down peak.

26. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means for selecting the mode or" operation of the cars in accordance with traffic conditions, the modes including a down peak mode of operation suitable for heavy down traffic and an up peak mode of operation suitable for heavy up traflic, means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down fioor calls that are lay-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a by-passed down fioor call to attend thereto, zoning means for selecting a car for service in the low zone, and means for preventing operation of said zoning means when the system is operating on a mode other than down peak, said rejected call means being operable irrespective of the mode of operation of the cars.

27. A lift system in which a plurality of cars serve a number of floors, the floors being divided into a high zone and a low zone, the system comprising means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down traflic and an up peak mode of operation suitable for heavy up traffic, means at the intermediate floors for registering up and down floor calls, means for causing an upwardly travelling car to stop at the floor of a down floor call that has acquired a predetermined time characteristic to attend thereto, zoning means for selecting a car for service in the low zone, and means for preventing operation of said zoning means when the system is operating on a mode other than down peak, the causing means being operable irrespective of the mode of operation of the cars.

28. A lift system in which a plurality of cars serve a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means for each car for causing the car when travelling down and when a certain condition exists to by-pass registered down floor calls, means for registering down floor calls that are by-passed, rejected call means for selecting an upwardly travelling car to stop at the floor of a bypassed down floor call to attend thereto, means for selecting the mode of operation of the cars in accordance with traflic conditions, the modes including a down peak mode of operation suitable for heavy down trafiic and in which cars are despatched from the upper terminal floor, means for returning cars to the upper terminal floor on completion of a trip when the system is on down peak, timing means for determining a minimum interval between despatch of the cars from the upper terminal floor, and reversal means for causing, whilst the system is on down peak, reversal of an upwardly travelling car at the highest down floor call when all cars are away from the upper terminal floor and the despatching interval for the next car to be despatched has expired, provided the rejected call means is not in operation.

29. A lift system in which a plurality of cars serve a number of floors, the system comprising means at the intermediate floors for registering up and down floor calls, means for causing an upwardly travelling car to stop at the floor of a down floor call that has acquired a predetermined time characteristic to attend thereo, means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down traflic and in which cars are despatched from the upper terminal floor, means for returning cars to the upper terminal floor on completion of a trip when the system is on down peak, timing means for determining a minimum interval between despatch of the cars from the upper terminal floor, and means for reversing, whilst the system is on down peak, an upwardly travelling car at the highest down floor call when all cars are away from the upper terminal floor and the despatching interval for the next car to be despatched has expired, provided the causing means is not in operation.

30. A lift system in which a plurality of cars serve a number of fioors, the floors being divided into a high zone and a low zone, the system comprising means at the intermediate floors for registering up and down floor calls, zoning means for selecting a car for service in the low zone, means for selecting the mode of operation of the cars in accordance with traflic conditions, the modes including a down peak mode of operation suitable for heavy down traffic and in which cars are despatched from the upper terminal floor, means for returning cars to the upper terminal floor on completion of a trip when the system is on down peak, timing means for determining a minimum interval between despatch of the cars from the upper terminal floor, and means for reversing, whilst the system is on down peak, an upwardly travelling car at the highest down floor call when all cars are away from the upper terminal floor and the despatching interval for the next car to be despatched has expired, provided the zoning means is not in operation.

31. A lift system in which a plurality of cars serve a 25 number of floors, the floors including an upper terminal floor and a main floor remote from the upper terminal floor, the system comprising means at the intermediate floors for registering up and down floor calls, means in each car for registering car calls, means for selecting the mode of operation of the cars in accordance with trafiic conditions, the modes including a down peak mode of operation suitable for heavy down traflic and in which the cars are despatched from the upper terminal floor, means for causing each car, when the system is on down pea to return to the upper terminal floor, and means,

26 when the system is on down peak," for cancelling, upon arrival of a car at the main floor, car calls registered in the car and for preventing l'e-registration of car calls in this car until a redetermined period following arrival of the car at said main floor.

References Cited in the file of this patent UNITED STATES PATENTS 2,624,425 Earnes fan. 6, 1953 2,68%8384 Yeasting Sept. 7, 1954 2,849,189 Santini et a1. June 24, 1958