Elevator Control Process And System

Abstract

A process and system for controlling a plurality of elevator cars servicing a plurality of service floor landings in which at least three specific floors are selected beside the basic floor where the number of passengers is largest so that some of these elevator cars can stand by at the basic floor and one of the elevator cars can stand by at each of the specific floors. The up and down hall call responding zones of each elevator car are determined so that it can respond to up and down hall calls originating from the floor at which the elevator car is situated and from the floors lying between this elevator car and the nearest upper and lower elevator cars.

Description

This invention relates to improvements in the process and system for controlling the operation of an elevator car group consisting of a plurality of elevator cars disposed for parallel operation in a building.

In a building in which a plurality of elevator cars are arranged for parallel operation under control of group control means, various operation modes are commonly prepared to deal with the traffic. For example, when the traffic is busy, the individual elevator cars are operated in a substantially uniformly dispersed condition within the overall service range, while when the traffic is idle, all the elevator cars are controlled so that they stand by at a basic floor and start to move only when calls are originated. Various other operation modes are presently employed. Suppose, for example, that a hall call is originated from one of upper floors of a multi-floor building in a condition in which the traffic is idle. Since one of the elevator cars standing by at the basic floor responds substantially to the hall call in such a case, the passenger standing at the service floor landing of the upper floor must wait anxiously for the elevator car departing the basic floor and moving upward toward the floor through many intermediate floors.

It is an object of the present invention to provide a process and system for controlling the operation of a plurality of elevator cars servicing a plurality of service floor landings in such a manner that these elevator cars can be suitably dispersed to stand by at different floors thereby reducing the waiting time for passengers and realizing an efficient parallel operation of the elevator car group.

Another object of the present invention is to provide a process and system for controlling a plurality of elevator cars in such a manner that, even when the number of operatable elevator cars is decreased, the remaining operatable elevator cars can be suitably dispersed to stand by at different floors.

A further object of the present invention is to provide a process and system for controlling a plurality of elevator cars in which means are provided so that, even when the preset dispersed stand-by mode is lost due to the operation of one or some of the elevator cars, the dispersed stand-by instructions for the unsuitable elevator cars can be cancelled and other suitable elevator cars can be selected to stand by at the predetermined floors.

One of the features of the present invention resides in the fact that a plurality of elevator cars are suitably dispersed to stand by at at least three specific floors including a basic floor and each elevator car responds to up hall calls originating from the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which the specific elevator car is situated and to down hall calls originating from the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which the specific elevator car is situated.

Another feature of the present invention resides in the fact that, in the system having the above feature, one or more elevator cars dispersed to stand by at their specific floors except the basic floor are returned to the basic floor when the number of operatable elevator cars is decreased to such an extent that it is no more possible to secure all the elevator cars previously scheduled to stand by at the specific floors and at the basic floor.

A further feature of the present invention resides in the fact that a plurality of stand-by zones each consisting of a plurality of continuous floors including one of the specific floors are preset and the dispersed stand-by instructions for one of the specific elevator cars are cancelled and transferred to another suitable elevator car when the specific elevator car moves out of its own stand-by zone.

Other objects, features and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompany drawings, in which:

FIG. 1 shows the manner of operation of elevator cars in response to hall calls in a known system in which such elevator cars are dispersed to stand by at a plurality of floors;

FIG. 2 shows the basic stand-by mode and hall call responding zones of individual elevator cars dispersed to stand by at different floors according to the present invention;

FIG. 3 shows one form of the change in the hall call responding zones of the individual elevator cars from the basic stand-by mode shown in FIG. 2 in response to a hall call;

FIG. 4 shows another form of the change in the hall call responding zones of the individual elevator cars according to the present invention;

FIG. 5 shows a further form of the change in the hall call responding zones of the individual elevator cars according to the present invention;

FIG. 6 shows one form of cancellation and transfer of the dispersed stand-by instructions according to the present invention;

FIG. 7 shows another form of cancellation and transfer of the dispersed stand-by instructions according to the present invention;

FIG. 8 shows the stand-by mode and service zones of the dispersed elevator cars when the number of opertable elevator cars is five;

FIG. 9 shows the stand-by mode and hall call responding zones of the dispersed elevator cars when the number of operatable elevator cars is four;

FIG. 10 shows the stand-by mode and hall call responding zones of the dispersed elevator cars when the number of operatable elevator cars is three;

FIG. 11 shows the structure of a circuit for detecting the number of operatable elevator cars in the system according to the present invention;

FIG. 12 shows the structure of a position detecting circuit provided for each elevator car in the system according to the present invention;

FIG. 13 shows the structure of a dispersed stand-by instruction circuit in the system according to the present invention;

FIG. 14 shows the structure of an auxiliary dispersed stand-by instruction circuit in the system according to the present invention;

FIG. 15 shows the structure of a service zone instruction circuit provided for each elevator car in the system according to the present invention; and

FIG. 16 shows the structure of a position detecting circuit for detecting the position of all the elevator cars in the system according to the present invention.

An elevator control method as described below has been proposed in an effort to obviate the drawbacks described previously. According to the proposed control method, the entire service range of a plurality of elevator cars arranged for parallel operation in a building is divided into a plurality of zones and these elevator cars are dispersed to stand by in the respective zones. The number of floors included in each zone is generally selected to be four to six although it varies depending on the structure of the building and operating conditions of the elevator cars. The elevator car standing by in each zone responds to hall calls originating from the floors belonging to that zone.

FIG. 1 shows by way of example the manner of dispersion of elevator cars according to the known process. Referring to FIG. 1, six elevator cars A to F are provided for servicing seven service floor landings in a building having seven floors and the seven floors are divided into three zones Z1, Z2 and Z3, the first zone Z1 including the first and second floors, second zone Z2 including the third, fourth and fifth floors, and third zone Z3 including the sixth and seventh floors. Suppose that the traffic is idle and the elevator cars A, B, C and F are standing by at the basic floor or first floor in the zone Z1, while the elevator cars D and E are standing by in the respective zones Z2 and Z3 as shown. The elevator cars D and E standing by in the second and third zones Z2 and Z3 may be at rest at one of floors in the zones depending on the previous operating conditions. Suppose, for example, that the elevator cars D and E stand by at the third and sixth floors respectively. Thus, when a down call is originated from the fifth floor, the elevator D responds to such call because it is standing by in the zone Z2. However, due to the fact that the elevator car D is situated at the third floor which is the lowest floor of the zone Z2, the elevator car D must move upward to the fifth floor, and after taking a passenger therein, reverses its moving direction as shown by the arrow a to move downward to the destination floor registered in the cage by the passenger.

Such manner of operation will be compared with the case in which the elevator car E standing by in the zone Z3 responds to the down call originating from the fifth floor and moves downward in a direction as shown by the arrow b. In the illustrated situation, the latter manner of operation is remarkably advantageous over the former manner of operation although we cannot simply conclude so in view of the problem of later zoning. Further, an up call may then be originated from the fourth or fifth floor. In such a case, the former manner of operation is inefficient in that the elevator car D which has moved downward in response to the down call from the fifth floor in the direction shown by the arrow a must move upward again to respond to the up call originating from the fourth or fifth floor. In contrast, the latter manner of operation is remarkably efficient in that the elevator car D can move upward to respond to the up call originating from the fourth or fifth floor even after the elevator car E responding to the down call originating from the fifth floor has move downward in the direction shown by the arrow b. However, the latter manner of operation is merely imaginary and cannot be put into practical use due to the fact that it ignores the significance of zoning.

In the present invention, at least three specific floors are selected as floors at which elevator cars are dispersed to stand by. More precisely, the first floor which may be the basic floor, third floor, fifth floor and seventh floor are selected as specific floors as shown in FIG. 2. In this arrangement, the number of specific floors is four and the elevator cars A, B and C stand by at the seventh, fifth and third floors respectively, while the elevator car D stands by at the first floor as a first dispatching car.

In the present invention, further, each elevator car is arranged to respond to up calls originating from the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which the specific elevator car is situated and to down calls originating from the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which the specific elevator car is situated. In the case of, for example, the elevator car C standing by at the third floor as shown in FIG. 2, the up and down hall call responding zones of this elevator car are determined so that it responds to up calls originating from the up hall call responding zone, i.e., from the floors ranging from the fourth floor one floor position below the fifth floor at which the nearest upper elevator car B stands by to the third floor at which it is situated and to down calls originating from the down hall call responding zone, i.e., from the floors ranging from the second floor one floor position above the first floor at which the nearest lower elevator car D stands by to the third floor at which it is situated. The call responding zones of the individual elevator cars are shown by the arrows in FIG. 2 and are tabulated below.

______________________________________ Up hall call Down hall call ______________________________________ 6th floor 7th floor Car B Car A 5th floor 6th floor 4th floor 5th floor Car C Car B 3rd floor 4th floor 2nd floor 3rd floor Car D Car C 1st floor 2nd floor ______________________________________

The arrangement of the elevator cars and determination of the call responding zones in this manner eliminates inefficient operation as previously described and ensures quite efficient operation of the elevator cars for calls originating from all the floors.

In the present invention, when the moving direction of any one of the elevator cars is determined, one of its up and down call responding zones from which calls in the direction opposite to the moving direction of the elevator car may originate is cancelled and one of the down and up call responding zones of the nearest upper or lower elevator car situated forward of this specific elevator car to be moved is extended to cover the cancelled call responding zone portion.

The call responding zone so extended of the nearest elevator car is clearly such as originating calls in the direction opposite to the moving direction of the first-mentioned specific car.

This change in the call responding zones will be described with reference to FIG. 3. Suppose, for example, that a down call shown by the symbol .gradient. is originated from the fifth floor and the elevator car B responding to such call starts to move downward. In such a case, the up call responding zone from which backward calls for the elevator car B, that is, in this case, up calls from the fifth and sixth floors may originate are cancelled, and the up call responding zone of the nearest lower elevator car C situated forward of or below the elevator car B is extended as shown. In FIG. 3, the elevator car B cannot respond to up calls from the fifth and sixth floors which have been included in the call responding zone of the elevator car B, due to the fact that the direction of movement of the elevator car B is decided to be the down-going direction. Therefore, the up call responding zone of the elevator car C is extended in the upward direction so as to cover such up hall calls. By virtue of the change in the call responding zones in this manner, the elevator car C can service the fifth or sixth floor landing without any increase in the waiting time for passengers even when an up call is originated from the fifth or sixth floor after a down call has been originated from the fifth floor.

In the present invention, furthermore, when any one of the elevator cars, after its moving direction has been determined and the one responding zone of the "forwardly situated" nearest elevator car has been extended to cover the cancelled zone of the moving elevator car, as described above in connection with FIG. 2, begins to move to another floor, one of the down and up call responding zones from which calls in the direction opposite to the moving direction of the elevator car may originate and at least a part of the other zone are cancelled and the down or up call responding zone of the nearest lower or upper elevator car situated backward of this moving specific elevator car is extended to cover the cancelled part of the "other" zone. The call responding zone so extended of the nearest elevator car is clearly such as originating calls in the moving direction.

This change in the call responding zones will be described with reference to FIG. 4. Referring to FIG. 4, the elevator car B responding to the down call from the fifth floor has started its downward movement. In such a case, the backward call for the elevator car B, that is, in this case down call from the fifth floor is cancelled and the down call responding zone of the nearest upper elevator car A situated backward of or above the elevator car B is extended as shown. In FIG. 4, the door of the elevator car B has been closed at the fifth floor landing and the elevator car B has started its downward movement. Since this elevator car B cannot respond to a down call originating later from the fifth floor, the down call responding zone of the elevator car A is extended to cover such a hall call. In the illustrated example, the elevator cars are dispersed to stand by at the four specific floors including the basic floor in the seven-storied building, and thus, the distance between these specific floors is short or corresponds to the spacing between two floor levels. However, in an actual elevator system, the number of floors is large and there is a greater spacing between these specific floors. Therefore, the elevator car B moving downward from one of the specific floors toward the nearest lower specific floor must pass a plurality of intermediate floors and the call responding zOne is changed as this elevator car passes through these intermediate floors.

It will thus be understood that, whenever one of the elevator cars is rendered incapable of responding to hall calls originating from its call responding zones due to movement in either direction, the call responding zones of another most convenient elevator car are extended. Therefore, whenever one of the elevator cars is rendered incapable of responding to hall calls for any other reasons than the positional reason, the call responding zones of other most convenient elevator cars should be similarly extended. When, for example, the elevator car C in FIG. 2 is loaded to its full capacity, the up call responding zone of the elevator car D is extended to cover up calls from the first to fourth floor, and the down call responding zone of the elevator car B is extended to cover down calls from the second and third floors, while the elevator car C is operated depending on the cage call registered by the passenger in the cage.

FIG. 5 shows the state in which the elevator car B having moved downward from the fifth floor as shown in FIG. 4 is at rest at the fourth floor and the elevator car D has moved upward to the fifth floor. It is needless to say that the elevator cars should be controlled to have the up and down call responding zones most suitable for their positions in spite of whatever changes in the relative positions of the elevator cars. To this end, arrangement is made so that each elevator car can respond to up calls originating from an up hall call responding zone consisting of the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which the specific elevator car is situated and to down calls originating from a down hall call responding zone consisting of the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which the specific elevator car is situated, irrespective of whatever changes in the relative positions of the elevator cars. Thus, according to the present invention, the call responding zones of the elevator cars are changed in a manner as shown by the thin solid lines in FIG. 5 and these new call responding zones are tabulated as follows:

Up hall call Down hall call ______________________________________ 6th floor 7th floor Car D Car A 5th floor 6th floor 4th floor 5th floor Car D Car B 3rd floor 4th floor Car B 2nd floor 3rd floor Car C Car C 1st floor 2nd floor ______________________________________

These call responding zones change successively with the operation of the elevator cars so that they can be continuously maintained most suitable for the situation. A problem arises as to whether the first dispatching instructions should be applied to the elevator car E or F standing by at the basic floor when a situation as shown in FIG. 5 occurs. However, any description as to such a case is not given herein as it has not any direct concern with the present invention.

In the foregoing description, the term "floor at which an elevator car is situated" is used to indicate such specific floor that an elevator car is situated at a position at which is can respond to a hall call originating from the specific floor. For example, even when the position of an elevator car is very close to the third floor, this elevator car is considered to be situated at the fourth floor when this elevator car has already passed through the third floor during its upward movement or when this elevator car is moving at a high speed and cannot stop at the third floor although its position is between the second and third floors.

Further, the terms "nearest upper elevator car" and "nearest lower elevator car" are used to denote such elevator cars which are situated at the nearest upper and lower positions respectively relative to a specific elevator car (an elevator car under consideration). In the case of the elevator car C in FIG. 5, no elevator cars are present below it due to the fact that the elevator cars E and F are cut off from the power supply and are not ready to operate. In such a case, the searching direction is reversed and the elevator car B at rest at the fourth floor is the nearest lower elevator car relative to the elevator car C. The nearest upper elevator should be similarly understood.

The number of specific floors in the present invention is at least three as described already and it is desirable that these specific floors include the basic floor. The term "basic floor" denotes generally the first floor at which the number of passengers is largest and a plurality of elevator cars can stand by thereat. In the present invention, however, the basic floor which is one of the specific floors is not necessarily the floor at which the number of passengers is largest, and any other suitable floor near such floor may be selected.

The foregoing description has referred to an improved stand-by system and determination of the call responding zones. However, this stand-by mode is not fixed at all and is flexible. Thus, when one of the elevator cars has moved to an unsuitable position, the dispersed stand-by instructions for this elevator car are cancelled and transferred to another suitable elevator car.

The elevator car, for example, the elevator car B in FIG. 4 is not situated at the fifth floor and it is considered to be situated at the fourth floor as described hereinabove. In this situation, no elevator car stands by at the intermediate specific floor or fifth floor although the elevator cars A and C stand by at the upper specific floor or seventh floor and lower specific floor or third floor respectively. In such a case, it is not preferable to readily apply the dispersed stand-by instructions to another elevator car. The elevator car B leaving the fifth floor may stop at the fourth floor, and after getting off of the passenger, its operation may be ended. In this case, the operation efficiency is higher when the elevator car B is moved upward to the fifth floor again than when another elevator car is instructed to move to the fifth floor. The same applies to any other elevator cars standing by at the specific floors.

As described previously, it is one of the objects of the present invention to provide, in a system in which a plurality of elevator cars are dispersed to stand by at at least three specific floors, means for cancelling the dispersed stand-by instructions for one of the elevator cars and transferring such instructions to another suitable elevator car. The cancellation of the dispersed stand-by instructions for one of the elevator cars and transfer of such instructions to another suitable elevator car, which is one of the features of the present invention, will be described with reference to FIG. 6.

Referring to FIG. 6, a stand-by zone Z3 is established and consists of a plurality of continuous floors, that is, the floors ranging from the second to the fourth floor including the lower specific floor or third floor. The dispersed stand-by instructions for the elevator car C standing by at the lower specific floor are not cancelled unless the elevator car C moves out of the stand-by zone Z3 consisting of the second, third and fourth floors. Therefore, upon completion of the service for any call originating from the floor in the stand-by zone Z3, the elevator car C is returned to the third floor again to stand by at this floor. On the other hand, when the elevator car C moves out of the stand-by zone Z3 in response to a call, the dispersed stand-by instructions for the elevator car C are cancelled. In this latter case, the operation efficiency will be improved when the instructions are applied to another suitable elevator car. After the elevator car C has moved out of the stand-by zone Z3, the instructions must be applied to another most suitable elevator car so that it is moved to and stand by at the lower specific floor. To this end, searching operation is carried out to find any elevator car which exists within this stand-by zone Z3 and is ready to move toward the third floor. If such elevator car is found in the zone Z3, it is desirable to apply the instructions thereto. If such elevator car is not found in this stand-by zone Z3, the instructions may be applied to the elevator car E standing by at the basic floor so as to move same to the third floor. This manner of zoning can easily realize the desired cancellation and transfer of the dispersed stand-by instructions. However, the above manner of operation will eventually result in a situation in which no elevator cars stand by at the basic floor if the remaining elevator car F may move upward for carrying passengers to the upper floors or in response to the application of the dispersed stand-by instructions.

Generally, the demand for elevator cars in a building is such that the demand for transfer from the basic floor toward the other floors can be considered to be substantially equal to the demand for transfer between the intermediate floors except the basic floor. Therefore, at least one elevator car should always stand by at the basic floor. It is therefore desirable to bring back at least one of the dispersed elevator cars to the basic floor when the number of elevator cars standing by at the basic floor is reduced to a predetermined number which may be zero or one. Further, in an "idle" traffic condition, the power supply for the M-G set or motor of the elevator cars standing by at the basic floor or any other specific floors is commonly stopped in a predetermined period of time after they are brought to the position to stand by at such position. The return of the inactive elevator car standing by at one of the specific floors requires energization of the M-G set thereof. Therefore, the elevator car in which the M-G set is in the energized state should only be brought to the basic floor. Further, in the case in which the elevator car or cars standing by at the basic floor are inactive due to the deenergization their M-G set, the dispersed stand-by instructions should not be cancelled even when the elevator cars dispersed in the respective stand-by zones may move out of such zones.

In the dispersed stand-by mode of the character above described, incapability of operation of one or some of the elevator cars due to, for example, maintenance and inspection, trouble, or emergency would lead to insufficient service of the entire elevator system, and some measures must be taken to deal with such a situation. Therefore, when the number of operatable elevator cars is decreased for some reasons, the dispersed stand-by mode must be suitably modified so as not to deteriorate the service for passengers.

This will be described with reference to FIG. 2 by way of example. When any one of the elevator cars is rendered inoperative, the elevator system is controlled so as to establish an operation mode in which as it were the elevator car E or F is eliminated in FIG. 2. By this manner of control, the desired satisfactory service can be realized except the case in which the number of passengers waiting at the basic floor landing is unusually large. FIG. 8 shows the state in which the elevator car E or F is eliminated from the arrangement shown in FIG. 2.

When two of the elevator cars are rendered inoperative, the elevator car standing by at the lower specifc floor (elevator car C in FIG. 2) is eliminated in addition to the elevator car E or F and the call responding zones of the remaining elevator cars are changed as seen in FIG. 9. When three of the elevator cars are rendered inoperative, the elevator car standing by at the intermediate specific floor (elevator car B in FIG. 2) is similarly additionally eliminated. The result is shown in FIG. 10.

Generally, the demand for elevator cars in a building is such that the demand for transfer from the basic floor (lobby floor) toward the other floors can be considered to be substantially equal to the demand for transfer between the intermediate floors excep the basic floor. It is therefore desirable to have a plurality of elevator cars standing by at the basic floor at whatever conditions. On the other hand, the purpose of the dispersed stand-by system is to shorten the waiting time for whatever hall calls. Thus, an excessively large lower limit of the number of elevator cars which should stand by at the basic floor is undesirable in that the service for hall calls originating from the intermediate floors will be deteriorated when the number of operatable elevator cars is decreased. In view of the above problem, the lower limit of the number of elevator cars standing by at the basic floor should be carefully selected to give the best result. In an application of the present invention to a group control system for controlling a group of elevator cars less than ten, a good result could be obtained when the lower limit of the number of elevator cars standing by at the basic floor was set at two.

In a group control system for controlling a group of six elevator cars as shown in FIG. 2, the setting of the lower limit of the number of elevator cars standing by at the basic floor becomes effective when two out of the six elevator cars are rendered inoperative, and the elevator car standing by at the lower specific floor nearest to the basic floor is eliminated. This results in the service mode shown in FIG. 9 and the two contradictory demands above described can thereby be satisfied in the most appropriate form. A situation in which more than two elevator cars are rendered inoperative simultaneously would not occur as a matter of fact. If such a situation would occur, the dispersed stand-by mode may be modified in a manner as shown in FIG. 10.

An embodiment of the system according to the present invention will now be described with reference to FIGS. 11 to 16. For simplicity of description, it is assumed that an elevator car bank consisting of six elevator cars A, B, C, D, E and F is provided in a seven-storied building for servicing the service floor landings of the first floor (bottom terminal) to the seventh floor. Although the basement and rooftop are not taken into consideration, they may be included in the service range of the elevator cars. Further, although no description is given herein as to an elevator system having express zones, the present invention is also applicable to such elevator system. FUrthermore, the present invention can be applied to any other elevator systems of different arrangement.

There are two traffic modes, that is, an idle traffic mode in which the traffic is not heavy or is idle in the day and a "busy" traffic mode in which the traffic is relatively heavy or busy during the remaining period of time of the day. The number of specific floors at which the elevator cars are initially dispersed to stand by is suitably determined depending on the number of elevator cars, number of service floor landings, presence or absence of express zones, and peculiarity of the floors (for example, heavy traffic due to presence of offices of the top management of a firm). However, description will be given herein as to the case in which the three elevator cars are dispersed so that each stands by at the upper specific floor or seventh floor, intermediate specific floor or fifth floor and lower specific floor or third floor, and the remaining three elevator cars stand by at the bottom terminal.

Before giving detailed description of the system, the name and function of various relays will be described. Those relays and contacts bearing the suffixes A, B, C, D, E and F in FIGS. 11 to 16 are provided for the respective elevator cars A, B, C, D, E and F, while those relays and contacts not bearing the suffixes A, B, C, D, E and F are common to all the elevator cars A, B, C, D, E and F. For simplicity of description, the relays and contacts associated with the elevator car A will solely be described. Further, for simplicity of illustration, the circuits associated with the elevator cars A and F and with the first and seventh floors are solely illustrated, and those associated with the elevator cars B to E and with the intermediate floors are shown by dotted lines or omitted, but it is apparent that similar circuits are provided for the latter.

10A . . . Operatable condition relay

This relay is energized when the elevator car A is capable of controlled operation. This relay is deenergized when the elevator car A is not capable of controlled operation due to, for example, trouble, maintenance and inspection, emergency or shut-down.

41A - 47A . . . Position detection relays

The less significant digit of the numeral designates the floor number, and the elevator car position is detected by the leading contactor on the elevator car. When the elevator car A is at rest at one of the floors, the position detection relay corresponding to such floor is energized, while when the elevator car A is moving, the position detection relay corresponding to the nearest floor at which the moving elevator car A can be stopped is energized. Therefore, this position varies depending on the actual physical position of the car and the moving speed of the car. For example, the position detection relay 44A is energized when the elevator car A is at rest at the fourth floor. However, when the elevator car A is moving upward past the fourth floor, the position detection relays 45A, 46A and 47A are energized when the speed of the elevator car A is low, intermediate and high respectively. Further, the energization and deenergization of these position detection relays takes place necessarily with a suitable overlap. For example, the position detection relay 44A is deenergized after energization of the position detection realy 45A when the elevator car A is moving upward toward the fifth floor from the fourth floor.

53A . . . Lower specific floor relay

This relay is energized when anyone of the position detection relays 42A, 43A and 44A is energized.

55A . . . Intermediate specific floor relay

This relay is energized when any one of the position detection relays 44A, 45A and 46A is elergized.

57A . . . Upper specific floor relay

This relay is energized when any one of the position detection relays 46A and 47A is energized.

53TA . . . Lower specific floor timing relay

This relay is energized in delayed relation in response to the energization of the lower specific floor relay 53A and is deenergized in delayed relation in response to the deenergization of the lower specific floor relay 53A.

55ta . . . intermediate specific floor timing relay

This relay is energized in delayed relation in response to the energization of the intermediate specific floor relay 55A and is denergized in delayed relation in response to the denergization of the intermediate specific floor relay 55A.

57ta . . . upper specific floor timing relay

This relay is energized in delayed relation in response to the energization of the upper specific floor relay 57A and is deenergized in delayed relation in response to the deenergization of the upper specific floor relay 57A.

11a . . . upward movement relay

This relay is energized during upward movement of the elevator car A.

12a . . . downward movement relay

This relay is energized during downward movement of the elevator car A

13a . . . deceleration position relay

This relay is energized when the elevator car A in motion reaches the decelerating position for each floor, and this decelerating position is determined by the moving speed of the elevator car A.

14a . . . full load detection relay

This relay is energized when the elevator car A is loaded to its full capacity.

15A . . . Stop relay

The elevator car A is decelerated to stop when this relay is energized.

16A . . . M-G relay

This relay is energized during operation of the M-G set of the elevator car A.

21a . . . upward movement selection relay

Upward movement is instructed when this relay is energized.

22A . . . Downward movement selection relay

Downward movement is instructed when this relay is energized.

23A . . . Stopping floor up call detection relay

This relay is energized when an up hall call is originated from the floor toward which the elevator car A is moving under deceleration or at which the car A is at rest.

24A . . . Stopping floor down call detection relay

This relay is energized when a down call is originated from the floor toward which the elevator car A is moving under decleration or at which the car A is at rest.

31A . . . Upward movement instruction relay

This relay is energized when the elevator car A is previously instructed for upward movement.

32A . . . Downward movement instruction relay

This relay is energized when the elevator car A is previously instructed for downward movement.

1CA - 7CA . . . Cage call relays

These relays are energized when cage calls are registered. The numeral represents the floor number.

70A . . . First dispatch relay

This relay is energized when the elevator car A stands by at the basic floor and is designated as a first dispatching car.

63A . . . Lower specific floor stand-by relay

When this relay is energized, the elevator car A stands by at the lower specific floor to operate in the call responding zone including the third floor.

65A . . . Intermediate specific floor stand-by relay

When this relay is energized, the elevator car A stands by at the intermediate specific floor to operate in the call responding zone including the fifth floor.

67A . . . Upper specific floor stand-by relay

When this relay is energized, the elevator car A stands by at the upper specific floor to operate in the call responding zone including the seventh floor.

69A . . . Stand-by relay

This relay is energized when the elevator car A is instructed to stand by at anyone of the upper, intermediate and lower specific floors and is deenergized with predetermined delay time when the instructions are cancelled.

10H . . . Three car operation relay

This relay is energized when three out of the six elevator cars are capable of controlled operation.

10M . . . Four car operation relay

This relay is energized when four out of the six elevator cars are capable of controlled operation.

10L . . . Five car operation relay

This relay is energized when five out of the six elevator cars are capable of controlled operation.

41UP - 46UP . . . Common position relays (up)

These relays are common to all the elevator cars and the less significant digit of the numeral represents the floor number. These relays are energized by the position relay of the elevator cars which are not instructed for downward movement.

42DN - 47DN . . . Common position relays (down)

These relays are common to all the elevator cars and the less significant digit of the numeral represents the floor number. These relays are energized by the position relay of the elevator cars which are not instructed for upward movement.

1UP-6UP . . . Up hall call relays

These relays are energized when up hall calls are registered. The numeral represents the floor number.

2DN-7DN . . . Down hall call relays

These relays are energized when down hall calls are registered. The numeral represents the floor number.

41P . . . Lobby stand-by relay

This relay is energized when anyone of the elevator cars stands by at the basic floor.

65P . . . Intermediate specific floor stand-by determination relay

This relay is energized when anyone of the elevator cars is instructed to stand by at the intermediate specific floor and is deenergized with predetermined delay time when the instructions are cancelled.

67P . . . Upper specific floor stand-by determination relay

This relay is energized when any one of the elevator cars is instructed to stand by at the upper specific floor and is deenergized with predetermined delay time when the instructions are cancelled.

79P . . . Common M - G relay

This relay is energized when all the M-G sets of the elevator cars standing by at the basic floor are deenergized.

It . . . idle traffic relay

This relay is energized when the traffic is idle.

Bt . . . busy traffic relay

This relay is energized when the traffic is relatively busy.

R1 - r11 . . . delay resistors

These resistors are provided for deenergizing the associated relay with predetermined timing.

C1 - c11 . . . delay capacitors

These capacitors are provided for deenergizating the associated relays with predetermined timing.

D1 - d7 . . . rectifiers

(+), (-) . . . Power supply buses

Remarks:

1. The relay coils of some of the relays are not shown.

2. The relay contacts in the drawings are shown in the deenergized state of the relays.

Now, itemized description of the practical operation of the system will be given with reference to FIGS. 11 to 16.

1. Selection of elevator cars to be dispatched from basic floor to stand by at upper, intermediate and lower specific floors.

For convenience of description, suppose that the idle operation mode is instructed in the state in which all the elevator cars are capable of controlled operation and stand by at the basic floor. (Actually, however, the busy operation mode is changed over to the idle operation mode, and the dispersed stand-by arrangement is employed in the busy operation mode too. Therefore, the situation in which all the elevator cars stand by at the basic floor does not generally exist.) In the above condition, the position detection relays 41A to 41F and operatable condition relays 10A to 10F for all the elevator cars are in the energized state. When the idle operation mode is instructed, the elevator car A is instructed to be the first dispatching car in the manner well known in the art and the first dispatch relay 70A is energized. Consequently, the three car operation relay 10H, four car operation relay 10M and five car operation relay 10L are energized by the circuits .sym. .fwdarw. 10D-4 .fwdarw. 10E-4 .fwdarw. 10F-4 .fwdarw. coil of 10H .fwdarw. IT-2 .fwdarw. .crclbar., .sym. .fwdarw. 10C-3 .fwdarw. 10D-3 .fwdarw. 10E-3 .fwdarw. 10F-3 .fwdarw. coil of 10M .fwdarw. IT-2 .fwdarw. .crclbar., and .sym. .fwdarw. 10A-1 .fwdarw. 10B-1 .fwdarw. 10C-1 .fwdarw. 10D-1 .fwdarw. 10E-1 .fwdarw. coil of 10L .fwdarw. IT-1 .fwdarw. .crclbar. respectively in FIG. 11. The upper specific floor stand-by relay 67A is energized by the circuit .sym. .fwdarw. 10A-6 .fwdarw. 70A-1 .fwdarw. 67P-1 .fwdarw. 63A-1 .fwdarw. 65A-2 .fwdarw. coil of 67A .fwdarw. 67B-4 .fwdarw. 67C-4 .fwdarw. 67D-6 .fwdarw. 67E-6 .fwdarw. 67F-6 .fwdarw. 10H-1 .fwdarw. .crclbar. in FIG. 13 and holds itself through the contact 67A-3 until the upper specific floor timing relay 57TA is energized. At the same time, the relay contacts 67A-1 and 67A-2 act to interlock the intermediate and lower specific floor stand-by relays 65A and 63A so that the elevator car A may not be instructed to stand by at the intermediate and lower specific floors, and further, the relay contacts 67A-4, 67A-5 and 67A-6 act to interlock the relays 67B, 67C, 67D, 67E and 67F so that the other elevator cars B to F may not be instructed to stand by at the upper specific floor.

After the elevator car A is instructed to stand by at the upper specific floor, the upward movement selection relay 21A is energized by the circuit .sym. .fwdarw. 12A-1 .fwdarw. 22A-1 .fwdarw. 32A-1 .fwdarw. coil of 21A .fwdarw. 47A-3 .fwdarw. 69A-9 .fwdarw. .crclbar. in FIG. 15. Upon establishment of known conditions for dispatching, the door is closed and locked and the upward movement relay 11A is energized for causing upward movement of the elevator car A toward the upper specific floor or seventh floor. When the leading contactor on the elevator car A reaches the level of the sixth floor, the sixth floor position detection relay 46A is energized and the upper specific floor relay 57A is energized in FIG. 12. Then, the upper specific floor timing relay 57TA is energized with predetermined delay time in FIG. 12. After the circuit .sym. .fwdarw. 41P-1 .fwdarw. 57A-2 .fwdarw. 63A-1 .fwdarw. 65A-2 .fwdarw. coil of 67A .fwdarw. .crclbar. is completed in FIG. 13, the self-holding circuit for the relay 67A through the contact 67A-3 thereof is released by the contact 57TA-1. Then, when the leading contactor on the elevator car A reaches the level of the seventh floor, the seventh floor position detection relay 47A is energized and the upward movement selection relay 21A is deenergized from its energized state due to the opening of the contact 47A-3 in FIG. 15. When the elevator car A reaches the seventh floor deceleration position determined by the moving speed thereof, the contact 13A-1 of the deceleration position relay 13A is closed and the stop relay 15A is energized by the circuits .sym. .fwdarw. 11A-2 .fwdarw. coil of 15A .fwdarw. 13A-1 .fwdarw. 21A-2 .fwdarw. 22A-2 .fwdarw. .crclbar. and .sym. .fwdarw. 11A-2 .fwdarw. coil of 15A .fwdarw. 13A-1 .fwdarw. D1 .fwdarw. 47A-2 .fwdarw. 67A-9 .fwdarw. .crclbar.. The relay 15A holds itself through the contact 15A-1 thereof and the elevator car A is decelerated to stop at the seventh floor. Of course, the elevator car A moving upward toward the seventh floor responds to a hall call originating from any one of the intermediate floors if such call appears during its upward movement, and after stopping at such floor, it moves again toward the seventh floor. Suppose, for example, that an up call is registered at the fourth floor landing before the leading contactor on the elevator car A reaches the level of the fourth floor. In this case, the up hall call relay 4UP is energized, and as soon as the leading contactor on the elevator car A reaches the level of the fourth floor, the fourth floor position detection relay 44A is energized to energize the common position relay (up) 44UP by the circuit .sym. .fwdarw. 10A-5 .fwdarw. 14A-3 .fwdarw. 32A-3 .fwdarw. 44A-7 .fwdarw. coil of 44UP .fwdarw. .crclbar. in FIG. 16. When the elevator car A reaches the fourth floor deceleration position determined by the moving speed thereof, the contact 13A-1 of the deceleration position relay 13A is closed and the stopping floor up call detection relay 23A is energized by the circuits .sym. .fwdarw. 11A-2 .fwdarw. coil of 15A .fwdarw. 13A-1 .fwdarw. 14A-1 .fwdarw. 22A-3 .fwdarw. D3 .fwdarw. 44A-3 .fwdarw. 4UP .fwdarw. 44UP-1 .fwdarw. 44A-6 .fwdarw. 14A-2 .fwdarw. .crclbar. and .sym. .fwdarw. 22A-4 .fwdarw. 32A-2 .fwdarw. 24A-1 .fwdarw. coil of 23A .fwdarw. 44A-3 .fwdarw. 4UP .fwdarw. 44UP-1 .fwdarw. 44A-6 .fwdarw. 14A-2 .fwdarw. .crclbar. in FIG. 15. Since the elevator car A must move further upward after stopping at the fourth floor, a known display is given by means such as a hall lantern or chime to the passenger waiting at the fourth floor landing. Then, the stop relay 15A is energized and the elevator car A is decelerated to stop at the fourth floor. Upon lapse of the period of time required for getting on and off of the passengers, the door is closed and locked again and the elevator car A moves upward toward the seventh floor due to the fact that the upward movement selection relay 21A is kept energized.

The manner of selection of the next elevator car to stand by at the intermediate specific floor will next be described.

Upon departure of the elevator car A toward the seventh floor, the first dispatching instructions for the elevator car A are cancelled in the manner well known in the art and the elevator car B is now instructed to be a first dispatching car. Further, due to the fact that the elevator car A has already been instructed to stand by at the upper specific floor, the upper specific floor stand-by determination relay 67P is energized by the circuit .sym. .fwdarw. 67A-8 .fwdarw. coil of 67P .fwdarw. .crclbar. in FIG. 14.

Thus, the intermediate specific floor stand-by relay 65B is energized by the circuit .sym. .fwdarw. 10B-6 .fwdarw. 70B-1 .fwdarw. 67P-2 .fwdarw. 65P-2 .fwdarw. 67B-1 .fwdarw. 63B-2 .fwdarw. coil of 65B .fwdarw. 65A-4 .fwdarw. 65C-4 .fwdarw. 65D-6 .fwdarw. 65E-6 .fwdarw. 65F-6 .fwdarw. 10M-1 .fwdarw. .crclbar. in FIG. 13 and holds itself through the contact 65B-3 thereof until the intermediate specific floor timing relay 55TB is energized. (Although the circuit for the elevator car B is not shown, it is similar to that for the elevator car A.) At the same time, the relay contacts 65B-1 and 65B-2 act to interlock the upper and lower specific floor stand-by relays 67B and 63B so that the elevator car B may not be instructed to stand by at the upper and lower specific floors, and the relay contacts 65B-4, 65B-5 and 65B-6 act to interlock the relays 65A, 65C, 65D, 65E and 65F so that the other elevator cars A, C, D, E and F may not be instructed to stand by at the intermediate specific floor.

After the elevator car B is instructed to stand by at the intermediate specific floor, the upward movement selection relay 21B is energized by the circuit .sym. .fwdarw. 12B-1 .fwdarw. 22B-1 .fwdarw. 32B-1 .fwdarw. coil of 21B .fwdarw. 47B-3 .fwdarw. 47B-2 .fwdarw. 47B-1 .fwdarw. 46B-4 .fwdarw. 46B-3 .fwdarw. 46B-2 .fwdarw. 46B-1 .fwdarw. 45B-4 .fwdarw. 45B-3 .fwdarw. 45B-5 .fwdarw. 65B-9 .fwdarw. .crclbar. in FIG. 15 as in the case of the elevator car A. Upon establishment of known conditions for dispatching, the door is closed and locked and the upward movement relay 11B is energized for causing upward movement of the elevator car B toward the intermediate specific floor or fifth floor.

When the leading contactor on the elevator car B reaches the level of the fourth floor, the fourth floor position detection relay 44B is energized and the intermediate specific floor relay 55B is energized in FIG. 12. Then, the intermediate specific floor timing relay 55TB is energized with predetermined delay time in FIG. 12. After the circuit .sym. .fwdarw. 41P-2 .fwdarw. 55B-2 .fwdarw. 67B-1 .fwdarw. 63B-2 .fwdarw. coil of 65B . . . .crclbar. is completed in FIG. 13, the self-holding circuit for the relay 65B through the contact 65B-3 thereof is released by the contact 55TB-1. Then, when the leading contactor on the elevator car B reaches the level of the fifth floor the position detection relay 45B is energized and the upward movement selection relay 21B is deenergized from its energized state due to the opening of the contacts 45B-3, 45B-4 and 45B-5. When the elevator car B reaches the fifth floor deceleration position determined by the moving speed thereof, the contact 13B-1 of the deceleration position relay 13B is closed and the stop relay 15B is energized by the circuit .sym. .fwdarw. 11B-2 .fwdarw. coil of 15B .fwdarw. 13B-1 .fwdarw. 21B-2 .fwdarw. 22B-2 .fwdarw. .crclbar.. The relay 15B holds itself through the contact 15B-1 thereof and the elevator car B is decelerated to stop at the fifth floor. The elevator car B moving upward toward the fifth floor responds to a hall call originating from any one of the intermediate floors if such call appears during its upward movement, and after stopping at such floor, it moves again toward the fifth floor as described previously with regard to the elevator car A. Further, when a call requesting service for the floor above the fifth floor is registered before the elevator car B arrives at the fifth floor deceleration position, the elevator car B moves directly to such floor without stopping at the fifth floor. Suppose, for example, that an up hall call is registered at the fourth floor landing by a passenger who wants to be transferred from the fourth to the sixth floor. In such a case, the elevator car B responds to the up hall call originating from the fourth floor to stop at the fourth floor, and after registration of a cage call requesting transfer to the sixth floor, moves upward toward the sixth floor. When the leading contactor on the elevator car B reaches the fifth floor level, the upward movement selection relay 21B is not deenergized even when the fifth floor position detection relay 45B is energized, due to the fact that the circuit .sym. . . . .fwdarw. coil of 21B .fwdarw. 47B-3 .fwdarw. 47B-2 .fwdarw. 47B-1 .fwdarw. 46B-4 .fwdarw. 46B-3 .fwdarw. 6CB .fwdarw. .crclbar. has been established. Therefore, the stop relay 15B is not energized and the elevator car B does not stop at the fifth floor even though the elevator car B reaches the fifth floor deceleration position and the deceleration position relay 13B is energized. Finally, the elevator car B is decelerated to stop at the sixth floor in the manner described previously when the leading contactor on the elevator car B reaches the sixth floor level. Upon stopping of the elevator car B at the sixth floor, the downward movement selection relay 22B is energized by the circuit .sym. .fwdarw. 11B-1 .fwdarw. 21B-1 .fwdarw. 31B-1 .fwdarw. coil of 22B .fwdarw. 41B-2 .fwdarw. 41B-3 .fwdarw. 41B-4 .fwdarw. 42B-1 .fwdarw. 42B-2 .fwdarw. 42B-3 .fwdarw. 42B-4 .fwdarw. 43B-1 .fwdarw. 43B-2 .fwdarw. 43B-3 .fwdarw. 43B-4 .fwdarw. 44B-1 .fwdarw. 44B-2 .fwdarw. 44B-3 .fwdarw. 44B-4 .fwdarw. 45B-1 .fwdarw. 45B-2 .fwdarw. 45B-5 .fwdarw. 65B-9 .fwdarw. .crclbar.. Upon lapse of the period of time required for getting on and off of the passengers, the door is closed and locked and the elevator car B moves downward toward the fifth floor. When the leading contactor on the elevator car B reaches the fifth floor level, the fifth floor position detection relay 45B is energized and the downward movement selection relay 22B is deenergized from the energized state due to the opening of the contacts 45B-1, 45B-2 and 45B-3. When the elevator car B reaches the fifth floor deceleration position determined by the moving speed thereof, the contact 13B-1 of the deceleration position relay 13B is closed and the elevator car B is decelerated to stop at the fifth floor in the manner described previously.

The manner of selection of the next elevator car to stand by at the lower specific floor will next be described.

Upon departure of the elevator car B toward the fifth floor, the first dispatching instructions for the elevator car B are cancelled in the manner well known in the art and the elevator car C is now instructed to be a first dispatching car. Further, due to the fact that the elevator cars A and B have been already instructed to stand by at the upper and intermediate specific floors respectively, the upper specific floor stand-by determination relay 67P and intermediate specific floor stand-by determination relay 65P are energized by the respective circuits .sym. .fwdarw. 67A-8 .fwdarw. coil of 67P .fwdarw. .crclbar. and .sym. .fwdarw. 65B-8 .fwdarw. coil of 65P .fwdarw. .crclbar. in FIG. 14.

Thus, the lower specific floor stand-by relay 63C is energised by the circuit .sym. .fwdarw. 10C-6 .fwdarw. 70C-1 .fwdarw. 67P-3 .fwdarw. 65P-3 .fwdarw. 65C-1 .fwdarw. 67C-2 .fwdarw. coil of 63C .fwdarw. 63A-5 .fwdarw. 63B-5 .fwdarw. 63D-6 .fwdarw. 63E-6 .fwdarw. 63F-6 .fwdarw. 10L-1 .fwdarw. .crclbar. in FIG. 13 holds itself through the contact 63C-3 thereof until the lower specific floor timing relay 53TC is energized. At the same time, the relay contacts 63C-1 and 63C-2 act to interlock the upper and intermediate specific floor stand-by relays 67C and 65C so that the elevator car C may not be instructed to stand by at the upper and intermediate specific floors, and the relay contacts 63C-4, 63C-5 and 63C-6 act to interlock the relays 63A, 63B, 63D, 63E and 63F so that the other elevator cars A, B, D, E and F may not be instructed to stand by at the lower specific floor.

After the elevator car C is instructed to stand by at the lower specific floor, the upward movement selection relay 21C is energized by the circuit .sym. .fwdarw. 12C-1 .fwdarw. 22C-1 .fwdarw. 32C-1 .fwdarw. coil of 21C .fwdarw. 47C-3 .fwdarw. 47C-2 .fwdarw. 47C-1 .fwdarw. 46C-4 .fwdarw. 46C-3 .fwdarw. 46C-2 .fwdarw. 46C-1 .fwdarw. 45C-4 .fwdarw. 45C-3 .fwdarw. 45C-2 .fwdarw. 45C-1 .fwdarw. 44C-4 .fwdarw. 44C-3 .fwdarw. 44C-2 .fwdarw. 44C-1 .fwdarw. 43C-4 .fwdarw. 43C-3 .fwdarw. 43C-5 .fwdarw. 63C-9 .fwdarw. .crclbar. in FIG. 15 as in the case of the elevator car B. Upon establishment of known conditions for dispatching, the door is closed and locked and the upward movement relay 11C is energized for causing upward movement of the elevator car C toward the lower specific floor or third floor.

When the leading contactor on the elevator car C reaches the level of the second floor, the second floor position detection relay 42C is energized and the lower specific floor relay 53C is energized in FIG. 12. Then, the lower specific floor timing relay 53TC is energized with predetermined delay time in FIG. 12. After the circuit .sym. .fwdarw. 41P-3 .fwdarw. 53C-2 .fwdarw. 65C-1 .fwdarw. 67C-2 .fwdarw. coil of 63C . . . .crclbar. is completed in FIG. 13, the selfholding circuit for the relay 63C through the contact 63C-3 thereof is released by the contact 53TC-1. Then, when the leading contactor on the elevator car C reaches the third floor level, the third floor position detection relay 43C is energized and the upward movement selection relay 21C is deenergized from the energized state due to the opening of the contacts 43C-3, 43C-4 and 43C-5. When the elevator car C reaches the third floor deceleration position determined by the moving speed thereof, the contact 13C-1 of the deceleration position relay 13C is closed and the stop relay 15C is energized by the circuit .sym. .fwdarw. 11C-2 .fwdarw. coil of 15C .fwdarw. 13C-1 .fwdarw. 21C-2 .fwdarw. 22C-2 .fwdarw. .crclbar.. The relay 15C holds itself through the contact 15C-1 thereof and the elevator car C is decelerated to stop at the third floor. The elevator car C moving upward toward the third floor responds to a hall call originating from the intermediate floor if such call appears during its upward movement, and after stopping at such floor, it moves again toward the third floor as described previously with regard to the elevator car A. Further, when a call requesting service for the floor above the third floor is registered before the elevator car C arrives at the third floor deceleration position, the elevator car C moves directly to such floor without stopping at the third floor as in the case of the elevator car B.

It will be understood from the above description that the elevator cars A, B and C are dispersed to stand by at the upper specific floor or seventh floor, intermediate specific floor or fifth floor and lower specific floor or third floor respectively and the remaining elevator cars D, E and F stand by at the basic floor. This state is shown in FIG. 2 and the elevator car D among those standing by at the basic floor is instructed to be a first dispatching car.

2. Service zone

The service zones of the elevator cars standing by at the upper, intermediate and lower specific floors and at the basic floor will be described hereunder. The elevator car A has been instructed to stand by at the upper specific floor and stands by now at the seventh floor. Therefore, the M-G relay 16A, position detection relay 47A, upper specific floor relay 57A, upper specific floor timing relay 57TA, upper specific floor stand-by relay 67A, stand-by relay 69A and common position relay 47DN are in the energized state. The elevator car B has been instructed to stand by at the intermediate specific floor and stands by now at the fifth floor in the state in which it is movable in either direction. Therefore, the M-G relay 16B, position detection relay 45B, intermediate specific floor relay 55B, intermediate specific floor timing relay 55TB, intermediate specific floor standby relay 65B, stand-by relay 69B and common position relays 45UP and 45DN are in the energized state. The elevator car C has been instructed to stand by at the lower specific floor and stands by now at the third floor in the state in which it is movable in either direction. Therefore, the M-G relay 16C, position detection relay 43C, lower specific floor relay 53C, lower specific floor timing relay 53TC, lower specific floor stand-by relay 63C, stand-by relay 69C and common position relays 43UP and 43DN are in the energized state. Further, the elevator car D has been instructed to be the first dispatching car and stands by at the basic floor. Therefore, the M-G relay 16D, position detection relays 41D, 41E and 41F, first dispatch relay 70D and common position relay 41UP are in the energized state and the stand-by relays 69D, 69E and 69F are in the deenergized state. Further, the lobby stand-by relay 41P, intermediate specific floor stand-by determination relay 65P and upper specific floor stand-by determination relay 67P are in the energized state and the common M-G relay 79P is in the deenergized state.

In the elevator car arrangement above described, the hall call responding zone of the elevator car A is determined by the circuits .crclbar. .fwdarw. 14A-2 .fwdarw. 47A-6 .fwdarw. 47DN-1 .fwdarw. 7DN and .crclbar. .fwdarw. 14A-2 .fwdarw. 47A-6 .fwdarw. 47DN-1 .fwdarw. 46DN-1 .fwdarw. 6DN in FIG. 15 so that the elevator car A can respond to down hall calls from the sixth and seventh floors as shown by the arrow in FIG. 2. Similarly, the hall call responding zones of the elevator car B are determined by the circuits .crclbar. .fwdarw. 14B-2 .fwdarw. 45B-6 .fwdarw. 45UP-2 .fwdarw. 5UP, .crclbar. .fwdarw. 14B-2 .fwdarw. 45B-6 .fwdarw. 45UP-2 .fwdarw. 46UP-2 .fwdarw. 6UP, .crclbar. .fwdarw. 14B-2 .fwdarw. 45B-6 .fwdarw. 45DN-2 .fwdarw. 5DN, and .crclbar. .fwdarw. 14B-2 .fwdarw. 45B-6 .fwdarw. 45DN-2 .fwdarw. 44DN-2 .fwdarw. 4DN in FIG. 15 so that the elevator car B can respond to up hall calls from the fifth and sixth floors and down hall calls from the fifth and fourth floors as shown by the arrows in FIG. 2. The hall call responding zones of the elevator car C are determined by the circuits .crclbar. .fwdarw. 14C-2 .fwdarw. 43C-6 .fwdarw. 43UP-3 .fwdarw. 3UP, .crclbar. .fwdarw. 14C-2 .fwdarw. 43C-6 .fwdarw. 43UP-3 .fwdarw. 44UP-3 .fwdarw. 4UP, .crclbar. .fwdarw. 14C-2 .fwdarw. 43C-6 .fwdarw. 43DN-3 .fwdarw. 3DN, and .crclbar. .fwdarw. 14C-2 .fwdarw. 43C-6 .fwdarw. 43DN-3 .fwdarw. 42DN-3 .fwdarw. 2DN in FIG. 15 so that the elevator car C can respond to up hall calls from the third and fourth floors and down hall calls from the third and second floors as shown by the arrows in FIG. 2. The all call responding zone of the elevator car D is determined by the circuits .crclbar. .fwdarw. 14D-2 .fwdarw. 70D-2 .fwdarw. 41UP-4 .fwdarw. 1UP and .crclbar. .fwdarw. 14D-2 .fwdarw. 70D-2 .fwdarw. 41UP-4 .fwdarw. 42UP-4 .fwdarw. 2UP in FIG. 15 so that the elevator car D can respond to up hall calls from the first and second floors as shown by the arrow in FIG. 2. In this manner, the hall call responding zones of the elevator cars dispersed most suitable for responding to all the hall calls can be determined without any overlap therebetween. Of course, all the elevator cars are movable for servicing all the service floor landings in response to cage calls. It will thus be understood that the up and down hall call responding zones of any one of the dispersed elevator cars are so determined that the specific elevator car can respond to up calls originating from the up hall call responding zone consisting of the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which the specific elevator car stands by and to down calls originating from the down hall call responding zone consisting of the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which the specific elevator car stands by.

The hall call responding zones of the dispersed elevator cars are changed in a manner as described below when one of the elevator cars moves in response to a hall call or cage call originating from the floors in one of its hall call responding zones.

Suppose, for example, that a down hall call (shown by the symbol .gradient. in FIG. 3) is registered by a passenger who wants to be transferred to the fourth floor from the fifth floor. Since the elevator car B stands by at the fifth floor and the down hall call originating from the fifth floor is included in the down hall call responding zone of the elevator car B, the stopping floor down call detection relay 24B for the elevator car B is energized by the circuit .sym. .fwdarw. 21B-4 .fwdarw. 31B-2 .fwdarw. 23B-1 .fwdarw. coil of 24B .fwdarw. 45B-1 .fwdarw. 5D .fwdarw. 45DN-2 .fwdarw. 45B-6 .fwdarw. 14B-2 .fwdarw. .crclbar.. The downward movement instruction relay 32B is energized to energize the down hall call lantern to tell the passenger that the elevator car B is ready to move downward, and at the same time, the door is opened. In response to the energization of the downward movement instruction relay 32B for the elevator car B, the common position relay 45UP is deenergized and the make contact 45UP-2 is opened in the elevator car B, with the result that the up hall calls from the fifth and sixth floors are no longer responded by the elevator car B. In this case, the break contact 45UP-3 is closed in the elevator car C, and the up hall call responding zone of the elevator car C is now determined by the circuits .crclbar..fwdarw.14C-2 .fwdarw.43C-6.fwdarw.43UP-3 .fwdarw.3UP, .crclbar..fwdarw.14C-2 .fwdarw.43C-6 .fwdarw.43UP-3 .fwdarw.44UP-3 .fwdarw.4UP, .crclbar..fwdarw.14C-2 .fwdarw.43C-6 .fwdarw.43UP-3 .fwdarw.44UP-3 .fwdarw.45UP-3 .fwdarw.5UP, and .crclbar..fwdarw.14C-2 .fwdarw.43C-6 .fwdarw.43UP-3 .fwdarw.44UP-3 .fwdarw.45UP-3 .fwdarw.46UP-3 .fwdarw.6UP. Thus, the up hall calls from the fifth and sixth floors are now included in the up hall call responding zone of the nearest lower elevator car C so that these calls are responded by the car C. This state is shown by the thin solid line in FIG. 3.

When the leading contactor on the elevator car B reaches the fourth floor level after it departs the fifth floor for carrying the passenger to the fourth floor, the position detection relays 44B and 45B are energized and deenergized respectively and the common position relays 44DN and 45DN are also energized and deenergized respectively. As a result, the contact 44DN-2 is opened and the contact 45DN-2 is closed in the elevator car B so that the down hall call from the fifth floor is no longer responded by the elevator car B. In this case, the circuit .crclbar..fwdarw.14A-2 .fwdarw.47A-6 .fwdarw.47DN-1 .fwdarw.46DN-1 .fwdarw.45DN-1 .fwdarw.5DN is established in addition to the circuits .crclbar..fwdarw.14A-2 47A-6 .fwdarw.47DN-1 .fwdarw.7DN and .crclbar..fwdarw.14A-2 .fwdarw.47A-6 .fwdarw.47DN-1 .fwdarw.46DN-1 .fwdarw.6DN in the elevator car A. Thus, the down hall call from the fifth floor is now included in the down hall call responding zone of the nearest upper elevator car A so that the down call is responded by the car A. This state is shown in FIG. 4.

Further, when, for example, the elevator car A standing by at the seventh floor is loaded to its full capacity with passengers who want to be transferred downward, the full load relay 14A for the elevator car A is energized and the break contact 14A-2 thereof is opened in FIG. 15. In this case, the elevator car A does not respond to any hall calls and has no hall call responding zone. Further, due to the fact that the break contact 14A-3 of the relay 14A is opened in FIG. 16, none of the common position relays are energized by the position detection relays for the elevator car A. Therefore, the common position relay 47DN having been energized is now deenergized and the circuits .crclbar..fwdarw.14B-2 .fwdarw.45B-6 45UP-2 .fwdarw.46UP-2 .fwdarw.47DN-2 .fwdarw.7DN and .crclbar..fwdarw.14B-2 45B-6 .fwdarw.45UP-2 .fwdarw.46UP-2 .fwdarw.47DN-2 .fwdarw.45DN-2 .fwdarw.6DN are established in FIG. 15 in addition to the circuits previously established in the nearest lower elevator car B. Thus, the down hall calls from the seventh and sixth floors are now included in the down hall call responding zone of the elevator car B.

It will thus be understood that the up and down hall call responding zones of the elevator cars standing by at the specific floors are changed or re-established depending on the determination of the moving direction of one of the cars, on the charge in the position of such car relative to the other cars and on whether any one of the cars is full loaded. Of course, such a change in the hall call responding zones occurs when two or more elevator cars are simultaneously placed in operation and when one of the elevator cars standing by at the basic floor is placed in operation. In other words, the hall call responding zones are continuously changed so that satisfactory service can be always offered depending on the moving direction, position and load of the elevator cars irrespective of the initial dispersed positions and number of elevators cars. This will be readily seen from the previous description given with reference to FIG. 5 and any detailed description is unnecessary.

As will be apparent from the foregoing detailed description, the novel and improved process for dispersing the elevator cars and determining the call responding zones thereof according to one of the features of the present invention is advantageous in eliminating wasteful operation, ensuring an efficient elevator car group control and reducing the waiting time for passengers waiting at the service floor landings.

3. Exchange of dispersed elevator cars

When a down hall call is originated from the floor in one of the call responding zones of the elevator car A standing by at the upper specific floor, the elevator car A departs the seventh floor in response to the registered call as described previously. As far as the leading contactor on the elevator car A lies associated with the upper, specific floor, that is, when the upper specific floor relay 57A is kept in the energized state, the elevator car A is kept instructed to stand by at the upper specific floor. However, when the leading contactor on the elevator car A is made not associated the upper specific floor, that is, when the upper specific floor relay 57A is deenergized, the instructions for the elevator car A are cancelled and another suitable elevator car is instructed to stand by at the upper specific floor in place of the elevator car A. According to the first condition, another elevator car is instructed to stand by at the upper specific floor when such elevator car is moving through the upper stand-by zone and the upper specific floor relay associated therewith is energized. According to the second condition, the first dispatching car standing by at the basic floor is instructed to stand by at the upper specific floor when any one of the elevator cars does not exist in the upper stand-by zone and any one of the upper specific floor relays is not energized. The elevator car A for which the stand-by instructions have been cancelled returns to the basic floor after offering the required service.

Suppose, for example, that a hall call is registered at the seventh floor landing by a passenger who wants to be transferred to the third floor from the seventh floor. Due to the fact that the elevator car A stands by at the seventh floor and a down hall call requesting transfer to another floor from the seventh floor is included in the call responding zone of the elevator car A, the stopping floor down call detection relay 24A for the elevator car A is energized by the circuit .sym..fwdarw.21A-4 .fwdarw.31A-2 .fwdarw.23A-1 .fwdarw. coil of 24A.fwdarw.47A-1 .fwdarw.7DN.fwdarw.47DN-1 .fwdarw.47A-6 .fwdarw.14A-2 .fwdarw..crclbar. in FIG. 15. The downward movement instruction relay 32A is energized to energize the down hall call lantern to tell the passenger that the elevator car A is ready to move downward, and at the same time, the door is opened. Then, when the passenger gets on the elevator car A and registers a cage call (3CA) requesting transfer to the third floor, the downward movement selection relay 22A is energized by the circuit .sym..fwdarw.11A-1 .fwdarw.21A-1 .fwdarw.31A-1 .fwdarw. coil of 22A .fwdarw.41A-2 .fwdarw.41A-3 .fwdarw.41A-4 .fwdarw.42A-1 .fwdarw.42A-2 .fwdarw.42A-3 .fwdarw.42A-4 .fwdarw.43A-1 .fwdarw.43A-2 .fwdarw.3CA .fwdarw..crclbar.. Upon lapse of the period of time required for getting on of the passenger, the door is closed and locked and the downward movement relay 12A is energized for causing downward movement of the elevator car A toward the third floor. When the leading contactor on the elevator car A reaches the fifth floor level from the sixth floor level as shown in FIG. 6, the position detection relay 45A is energized and the position detection relay 46A is deenergized. As a result, the upper specific floor relay 57A is deenergized and the upper specific floor timing relay 57TA is deenergized with predetermined delay time. The upper specific floor standby relay 67A in FIG. 13 is deenergized from its energized state due to the opening of the make contact 57A-1 of the upper specific floor relay 57A, and the break contacts 67A-5 and 67A-6 of the upper specific floor stand-by relay 67A are closed so that another suitable elevator car can now be selected for stand-by at the upper specific floor. Suppose, for example, that the elevator car F is in operation in the upper stand-by zone at this time as shown in FIG. 6. Then, the upper specific floor relay 57F for the elevator car F is in the energized state and the upper specific floor stand-by relay 67F for the elevator car F is energized by the circuit .sym..fwdarw.10F-6 .fwdarw.41P-6 .fwdarw.57F-2 .fwdarw.63F-1 .fwdarw.65F-2 .fwdarw.coil of 67F .fwdarw.67D-5 .fwdarw. 67E-5 .fwdarw.67A-6 .fwdarw.67B-6 .fwdarw.67C-6 .fwdarw.10H-1 .fwdarw..crclbar., and the elevator car F is instructed to stand by at the upper specific floor.

When any one of the elevator cars does not exist in the upper stand-by zone, the upper specific floor standby determination relay 67P is deenergized with predetermined delay time after the deenergization of the upper specific floor stand-by relay 67A for the elevator car A. Due to the deenergization of the upper specific floor stand-by determination relay 67P, the upper specific floor relay 67D for the first dispatching elevator car D standing by at the basic floor is energized by the circuit .sym..fwdarw.10D-6 .fwdarw.70D-1 .fwdarw.67F-4 .fwdarw.63D-1 .fwdarw.65D-2 .fwdarw. coil of 67D .fwdarw.67E-4 .fwdarw.67F-4 .fwdarw.67A-6 .fwdarw.67B-6 .fwdarw.67C-6 .fwdarw.10H-1 .fwdarw..crclbar., and the elevator car D is instructed to stand by at the upper specific floor and departs the basic floor toward the seventh floor.

The stand-by relay 69A is deenergized in the case of the elevator car A for which the stand-by instructions have been cancelled. The elevator car A stops at the third floor in response to the cage call, and after getting off of the passenger, the downward movement selection relay 22A is energized by the circuit .sym..fwdarw.11A-1 .fwdarw.21A-1 .fwdarw.31A-1 .fwdarw. coil of 22A .fwdarw.41A-2 .fwdarw.69A-3 .fwdarw..crclbar. for causing downward movement of the elevator car A toward the basic floor. Consequently, the elevator cars A and F stand by at the basic floor and seventh floor respectively as seen in FIG. 6.

The elevator car B stands by at the intermediate specific floor or fifth floor. When this elevator car B moves out of the intermediate stand-by zone including the fourth, fifth and sixth floors in response to a call originating from such floors, another suitable elevator car is instructed to stand by at the intermediate specific floor in a manner as described above. The same applies to the elevator car C standing by at the lower specific floor or third floor and to any other elevator cars.

It will thus be understood that the stand-by instructions for any one of the elevator cars standing by at the upper, intermediate and lower specific floors are not cancelled when it services the service floor landings in its own stand-by zone in response to a call originating from such zone and the elevator car returns to the specific floor again to stand by at such floor after servicing. When, however, the specific elevator car moves out of its own stand-by zone in response to a call requesting service to the floor outside of its own stand-by zone, another suitable elevator car is instructed to stand by at the specific floor and the specific elevator car returns to the basic floor to stand by thereat after servicing.

Further, when no elevator cars stand by at the basic floor or when the number of elevator cars standing by at the basic floor is decreased to less than a predetermined lower limit due to the fact that the elevator cars standing by at the basic floor depart successively the basic floor for carrying many passengers, the stand-by instructions for the elevator car or cars standing by at the upper, intermediate and lower specific floors are cancelled so that these elevator cars can be returned to the basic floor, and the remaining elevator car or cars are instructed to stand by at the specific floors.

Suppose, for example, that the elevator cars D, E and F standing by at the basic floor depart the basic floor successively in the state shown in FIG. 2. Then, the position detection relays 41D, 41E and 41F for the respective elevator cars D, E and F are deenergized and the lobby stand-by relay 41P is deenergized in FIG. 14. Due to the opening of the contacts 41P-1, 41P-2 and 41P-3 of the relay 41P, the specific floor stand-by relays 67A, 65B and 63C for the elevator cars A, B and C standing by at the upper, intermediate and lower specific floors respectively are deenergized in FIG. 13, and the stand-by relays 69A, 69B and 69C for the respective elevator cars A, B and C are deenergized so that these elevator cars move toward the basic floor. At the same time, the contacts 69D-1, 69E-1 and 69F-1 are closed due to the energization of the stand-by relays 69D, 69E and 69F for the elevator cars D, E and F which have departed the basic floor, and these elevator cars are now instructed to stand by at the specific floors.

When the traffic is reduced and calls cease to be originated from the stand-by zones of the elevator cars for some period of time, the M-G set of each elevator car is deenergized after a predetermined period of time and the elevator cars stand by in such a state. When any one of the elevator cars standing by at the upper, intermediate and lower specific floors moves out of its stand-by zone in response to a call originating from such zone in the state in which all the elevator cars standing by at the basic floor have their M-G set deenergized, the stand-by instructions for the specific elevator car are not cancelled and the specific elevator car returns to the previously instructed specific floor again after servicing. Further, even when all the elevator cars standing by at the basic floor depart the basic floor to deal with an increase in passengers in the state in which all the elevator cars standing by at the upper, intermediate and lower specific floors have their M-G set deenergized, the dispatched elevator cars are not instructed to stand by at the specific floors and return to the basic floor again after servicing.

Suppose, for example, that all of the elevator cars D, E and F standing by at the basic floor have their M-G set deenergized in the state shown in FIG. 2. Then, the M-G relays 16D, 16E and 16F for these elevator cars D, E and F are deenergized and the common M-G relay 79P is energized by the circuit .sym..fwdarw.69A-2 .fwdarw.69B-2 .fwdarw.69C-2 .fwdarw.16D-2 .fwdarw.16E-2 .fwdarw.16F-2 .fwdarw. coil of 79P .fwdarw..crclbar. in FIG. 14. The specific floor stand-by relays 67A, 67B and 67C for the elevator cars A, B and C hold themselves through the contacts 79P-1, 79P-2 and 79P-3 respectively in FIG. 13 and the self-holding state is maintained even though the elevator cars move out of their own stand-by zones.

Further, the deenergization of the M-G set of the elevator cars A, B and C standing by at the upper, intermediate and lower specific floors results in the opening of the contacts 16A-1, 16B-1 and 16C-1 of the respective M-G relays 16A, 16B and 16C. Thus, the specific floor stand-by relays 67A, 65B and 63C for these elevator cars are not deenergized and the stand-by instructions are kept applied to these elevator cars even when all of the elevator cars standing by at the basic floor depart the basic floor and the lobby stand-by relay 41P is deenergized.

As will be apparent from the foregoing detailed description, one of the features of the present invention resides in the fact that, in an elevator control system for controlling a plurality of elevator cars dispersed to stand by at a plurality of specific (but not fixed and variable) floors, a plurality of stand-by zones each consisting of a plurality of continuous floors including one of the specific floors are preset and the stand-by instructions for one of the specific elevator cars are cancelled and transferred to another suitable elevator car when the specific elevator car moves out of its own stand-by zone. This arrangement is advantageous in that wasteful operation can be minimized and the elevator cars can be efficiently dispersed.

4. Alteration of dispersed cars depending on the number of operatable cars

The dispersed stand-by mode according to the present invention is suitably altered in a manner as described below when one or some of the elevator cars are rendered inoperative.

The operatable condition relays 10A, 10B, 10C, 10D, 10E and 10F are deenergized when the respective elevator cars A, B, C, D, E and F are rendered inoperative due to, for example, maintenance and inspection, trouble or emergency. The three car operation relay 10H shown in FIG. 11 is energized when three out of the six elevator cars are capable of operation. Similarly, the four and five car operation relays 10M and 10L are energized when four and five respectively out of the six elevator cars are capable of operation. Therefore, all of these relays 10H, 10M and 10L are energized even when one of the six operatable condition relays is deenergized. The relays 10M and 10H are energized and the relay 10L is deenergized when two of the six operatable condition relays are deenergized. The relay 10L is solely energized when three of the six operatable condition relays are deenergized. Further, all of these relays 10L, 10M and 10H are deenergized when four of the six operatable condition relays are deenergized.

Referring to FIG. 13, the contact 10L-1 of the five car operation relay 10L is closed in response to the energization of this relay 10L and the lower specific floor stand-by instruction circuit becomes active when at least five among the six elevator cars are capable of operation. The contact 10M-1 of the relay 10M is closed in response to the energization of this relay 10M and the intermediate specific floor stand-by instruction circuit becomes active when at least four among the six elevator cars are capable of operation. Similarly, the contact 10H-1 of the relay 10H is closed in response to the energization of this relay 10H and the upper specific floor stand-by instruction circuit becomes active when at least three among the six elevator cars are capable of operation.

When, for example, four among the six elevator cars are capable of operation, the upper and intermediate specific floor stand-by instruction circuits are active so that one of the elevator cars is selectively instructed to stand by at the upper specific floor, another elevator car is selectively instructed to stand by at the intermediate specific floor, and the remaining two elevator cars are instructed to stand by at the basic floor. In other words, when at least two elevator cars stand by at the basic floor in spite of shutdown of any one of the remaining elevator cars, no alteration is applied to the dispersed stand-by arrangement, while when this condition is not satisfied, the stand-by instructions for the elevator cars standing by at the intermediate floors are successively cancelled starting from the elevator car nearest to the basic floor so as to preferentially secure the elevator cars which should stand by at the basic floor.

Further, in response to the deenergization of the operatable condition relay for any one of the elevator cars A, B, C, D, E and F, the contact 10A-5, 10B-5, 10C-5, 10D-5, 10E-5 or 10F-5 is opened in FIG. 16 so that the common position relays, which are energized depending on the stopping position of the elevator car, cannot be energized. Thus, this elevator car cannot possess any stand-by zone. Further, when the number of operatable elevator cars is decreased and the stand-by instructions are cancelled correspondingly, for example, when the stand-by instructions for the elevator car standing by at the lower specific floor are cancelled at first in FIG. 15, the elevator car standing by at the third floor returns to the basic floor to stand by now at the basic floor. In this situation, up hall calls from the third and fourth floors are included in the up hall call responding zone of the first dispatching elevator car standing by at the basic floor and down hall calls from the third and second floors are included in the down hall call responding zone of the elevator car standing by at the intermediate specific floor or fifth floor as seen in FIG. 9. In an idle traffic condition, at least one elevator car stands by always at the lobby floor or basic floor and at least two elevator cars stand by at the specific floors as seen in FIG. 9. Thus, passengers can get on the elevator cars without any substantial waiting time and economical and satisfactory service can be offered.

The above description has referred to the alteration of the dispersed stand-by mode depending on the number of operatable elevator cars. However, when one of these elevator cars is rendered inactive in the above operation mode, such elevator car is eliminated from the stand-by position in the same manner as described above and the dispersed stand-by mode is further altered depending on the number of operatable elevator cars.

In a busy traffic condition, the number of passengers who want to be transferred upward is substantially equal to the number of passengers who want to be transferred downward. The operation mode in such a traffic condition will next be described.

When the traffic mode is changed over from idle to busy according to one of various known methods with the increase in the number of passengers, the idle traffic relay IT is deenergized and the busy traffic relay BT is energized. The five car operation relay 10L is deenergized due to the opening of the contact IT-1 of the relay IT in FIG. 11, while the three car operation relay 10H and four car operation relay 10M are kept energized through the contact BT-2 of the relay BT. As a result, the contact 10L-1 of the relay 10L is opened in FIG. 13 and the lower specific floor stand-by instruction circuit becomes inactive. Although the lower specific floor stand-by instruction circuit has been rendered inactive by way of example, the upper or intermediate specific floor standby instruction circuit may be rendered inactive and the specific stand-by floors may be easily altered. More precisely, the elevator car standing by at the fifth floor in FIG. 9 may be brought to the fourth floor to stand by at such floor, or the elevator car standing by at the seventh floor in FIG. 10 may be brought to the fifth or sixth floor to stand by at such floor. At least one elevator car stands by always at the basic floor as in the case of the idle traffic condition, so that this elevator car can cooperate with another elevator car instructed to stand by always at the upper specific floor and another elevator car instructed to stand by always at the intermediate specific floor for responding to hall calls originating from their call responding zones and to cage calls.

Therefore, each of the elevator cars responds to forward hall calls originating from the zone ranging from the moving position thereof to the position of another preceding elevator car moving in the same direction when such preceding elevator car exists. On the other hand, when no preceding elevator car exists in the advancing direction of such elevator car, this latter elevator car responds to forward hall calls originating from the floors forward thereof and to backward hall calls for another elevator car moving in the opposite direction past the floor nearest to that elevator car. For example, when one of the elevator cars is moving upward to the second floor and the preceding elevator car is moving upward to the sixth floor past the fifth floor, the former elevator car responds to up calls originating from the second, third, fourth and fifth floors. On the other hand, when one of the elevator cars is moving upward to the sixth floor past the fifth floor, no preceding elevator car exists in the same direction and another elevator car whose position is nearest thereto in the opposite direction is moving downward past the fifth floor, the former elevator car responds to up calls originating from the floors above and including the sixth floor and to down calls originating from the floors above and including the sixth floor. Therefore, the elevator car changes the direction of movement and returns to the basic floor when no forward hall calls are originated from its own call responding zones in spite of origination of other forward hall calls (in other words, when such calls are included in the call responding zones of the preceding elevator car and are responded thereby), when no cage calls are registered, and when the specific elevator car is not instructed to stand by at any one of the specific floors. In this manner, the individual elevator cars are operated in suitably dispersed relation to offer service of good quality such that passengers standing at different floor landings wait substantially the same period of time.

In a transient state in which the traffic mode is nearly changed over from busy to idle due to the decrease in the number of passengers, the upper and intermediate specific floor stand-by instruction circuits are active. Therefore, the elevator cars are suitably dispersed without standing by at the basic floor in the number more than is required and the elevator cars standing by at the specific floors respond quickly to calls originated by passengers waiting at the upper and intermediate floors. Thus, the passengers can get on the elevator cars without waiting for any substantial period of time.

It will thus be understood that, according to one of the features of the present invention, the dispersed stand-by mode is suitably altered to deal with not only the idle traffic mode but also the busy traffic mode so as to improve the service in the busy traffic mode.

Claims

What we claim is:

1. A process for controlling a plurality of elevator cars servicing a plurality of service floor landings comprising selecting at least three specific floors among all the floors and suitably dispersing said elevator cars to stand by at said specific floors so that each of said dispersed elevator cars can respond to up hall calls originating from an up hall call responding zone consisting of the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which said specific elevator car is situated and to down hall calls originating from a down hall call responding zone consisting of the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which said specific elevator car is situated.

2. An elevator control process as claimed in claim 1, wherein when the direction of movement of an elevator car is determined, one of said hall call responding zones of said elevator car from which zone, hall calls in the direction opposite to said direction of movement of said car originate is cancelled, and one of hall call responding zones of another elevator car nearest to the first-mentioned elevator car in said direction of movement of the first-mentioned elevator car is extended to cover said cancelled hall call responding zone, hall calls originating from said one of hall call responding zones of said other elevator car being in the direction opposite to the direction of movement of the first-mentioned elevator car.

3. An elevator control process as claimed in claim 2, wherein when an elevator car is moving from its original floor position to another floor position in said direction of movement, at least a part of the other hall call responding zone of said elevator car from which zone, hall calls in said direction of movement originate is further cancelled, and one of hall call responding zones of another elevator car nearest to the first-mentioned elevator car in the direction opposite to said direction of movement of the first-mentioned elevator car is extended to cover said cancelled part of said other hall call responding zone, hall calls originating from said one of hall call responding zones of said other elevator car being in the direction of movement of the first-mentioned elevator car.

4. An elevator control process as claimed in claim 1, wherein when an elevator car is loaded with more than a predetermined load, the up hall call responding zone and the down hall call responding zone of said elevator car are cancelled, and the hall call responding zones of the nearest upper and lower elevator cars relative to said elevator car are extended to cover said cancelled hall call responding zones.

5. A process for controlling a plurality of elevator cars servicing a plurality of service floor landings comprising suitably dispersing said elevator cars so that each of said elevator cars can respond to up hall calls originating from an up hall call responding zone consisting of the floors ranging from the floor one floor position below the floor position of the nearest upper elevator car to the floor at which said specific elevator car is situated and to down hall calls originating from a down hall call responding zone consisting of the floors ranging from the floor one floor position above the floor position of the nearest lower elevator car to the floor at which said specific elevator car is situated, irrespective of any variations in the relative positions of the individual elevator cars.

6. An elevator control process as claimed in claim 1, wherein said at least three specific floors include the basic floor at which elevator cars should always stand by.

7. An elevator control process as claimed in claim 1, wherein the floor at which the number of passengers is largest is selected to be one of said at least three specific floors.

8. An elevator control process as claimed in claim 1, wherein the floor at which the number of passengers is the largest is selected to be one of said at least three specific floors, and said selected floor is the basic floor at which elevator cars should always stand by.

9. An elevator control process as claimed in claim 6, wherein when the number of operatable elevator cars is decreased to such an extent that it is no more possible to secure all the elevator cars previously scheduled to stand by at said specific floors and at said basic floor, the number of said specific floors is decreased to the same extent.

10. An elevator control process as claimed in claim 9, wherein at least one of said selected specific floors nearer to said basic floor than the other specific floors is returned to be a usual floor at which no elevator car stands by.

11. An elevator control system for controlling a plurality of elevator cars servicing a plurality of service floor landings comprising means for selecting at least three specific floors among all the floors for dispersing said elevator cars to said specific floors, means establishing a plurality of stand-by zones each consisting of predetermined successive floors including one of said specific floors, means for detecting the position and moving direction of the individual elevator cars, means for selecting elevator cars as dispersed stand-by cars at said specific floors in response to the outputs of said stand-by zone establishing means and said position and moving direction detecting means, means for instructing the selected cars to stand by at said specific floors, and means for causing said dispersed stand-by cars to stop at said individual specific floors instructed by said stand-by instruction means.

12. An elevator control system as claimed in claim 11, wherein said stand-by instruction means includes means for cancelling the stand-by instructions for an elevator car standing by at its originally associated specific floor when said elevator car moves out of said standby zone.

13. An elevator control system as claimed in claim 11, wherein said stand-by instruction means includes means for applying the stand-by instructions to an elevator car which is present in a stand-by zone including one of said specific floors to which said elevator car was not originally dispersed and tends to move toward said specific floor.

14. An elevator control system as claimed in claim 11, wherein said stand-by instruction means includes means for applying the stand-by instructions to one of a plurality of said elevator cars standing by at the basic floor at which such elevator cars should always stand by among said specific floors, when any elevator car tending to move toward one of said specific floors except said basic floor is not present in the zone including said specific floor.

15. An elevator control system as claimed in claim 12, wherein said at least three specific floors include the basic floor at which elevator cars should always stand by, and means is provided for cutting off the output of said stand-by instruction cancelling means when none of said elevator cars standing by at said basic floor have their motors energized.

16. An elevator control system as claimed in claim 11, wherein said at least three specific floors include the basic floor at which elevator cars should always stand by, and means is provided for applying the basic floor returning instructions to an elevator car standing by at its specific floor with the motor thereof energized, when a predetermined number of elevator cars are not standing by at said basic floor.