In very tall buildings it is generally not economically possible to build elevator shafts extending through the entire height of the building with elevators running from the ground floor to the top floor so that each elevator would serve all floors. For this reason, the building is often divided vertically into zones, of which the lowest zone is a so-called low-rise zone extending from the en- trance floor to a certain height, with some of the eleva- tors in the building serving the traffic needs of the floors in this zone while the rest of the elevators in the building serve primarily or exclusively the floors above the low-rise zone. Hereinafter, the entrance floor may also be called ground floor, even in cases where the building has floors below the entrance floor and has ele- vator traffic to these floors. Conventionally, the eleva- tor traffic to the highest floors in very tall buildings is implemented by using one or more so-called sky lobbies, which are served by elevators running between sky lobbies and entrance floors, generally shuttle elevators that do not stop at any other floors, and local elevators serving the floors within their zone. The zone containing the top- most floors in the building, and sometimes also the zone below it, is called a high-rise zone. Depending on the height of the building, between these zones there may be one or more intermediate zones, i. e. so-called mid-rise

zones, for serving the intermediate floors from their own sky lobbies.

In respect of elevator lay-out and control of service, lo- cal elevators serving different zones may form one or more elevator groups or they may belong to the same elevator group, and so may the shuttle elevators in the building.

The sky lobbies as well as the entrance lobby may comprise several floors, especially if the shuttle elevators have a car with two or more decks. In the case of an elevator car with two decks, i. e. a so-called double-deck elevator car, the entrance lobby and the sky lobbies are usually two- floor solutions in which the upper passenger compartment of a double-deck elevator car stops at the upper floor of a two-floor entrance lobby or sky lobby and the lower pas- senger compartment correspondingly at the lower floor of the entrance lobby or sky lobby. A double-deck shuttle elevator can also be applied in solutions where some of the entrance and sky lobbies comprise two floors and some only one floor, e. g. in such manner that the entrance lobby comprises two floors and the sky lobby one floor, in which case a double-deck elevator car may have to park with both the upper and the lower passenger compartment separately at a one-floor elevator lobby.

A typical group is a group consisting of eight elevators and serving a single zone, which may consist of e. g. floors 1-15. Often such an elevator group is needed for each zone, for example for the mid-rise zone for floors 16-30 and the high-rise zone for floors 31-45.

In tall buildings, elevator shafts are used as load- bearing structures, which often or at least to a very

large degree support and stiffen not only the elevator shafts themselves but also all the rest of the building.

Thus the elevator shafts usually form a continuous struc- ture extending from the basement of the building up to the highest floors in the building. This takes up a fairly large space in the building and it is not necessarily even fully utilized by the elevator system of the building or otherwise. The elevators serving the mid-rise and high- rise zones do not stop at lower floors, so the lobby space and especially the shaft space required by them constitute waste space expensive to the owner of the building. Unused lobby space can be utilized e. g. as storage or lavatory space on different floors, but corresponding shaft space can generally not be utilized in any way.

A prior-art solution for an elevator arrangement for high- rise buildings is presented in US patent no. US 5, 419, 414.

In this solution, three elevator cars are installed one above the other in the same shaft in such manner that each car is moved separately by an elevator machine placed above the shaft shared by the three cars. In other words, for each car a. separate machine is provided, from which the elevator ropes run in an overlapping manner to the elevator cars so that the ropes going to the bottommost car run past the two cars above it and the ropes going to the mid-region car run past the topmost car. The cars can be moved in relation to each other on at least four dif- ferent operating principles. According to a first princi- ple, each car always travels in its own section of the shaft and never enters the zone of another car. According to a second principle, each car can serve all floors, but only car may be moving at a time. According to a third principle, the cars can move simultaneously in different

zones but only in the same direction at a time. Finally according to a fourth operating principle, the cars can travel simultaneously in different directions, provided that safety is guaranteed. For example, when the two cars below the topmost one are going downwards, the topmost car can go upwards. The elevator system proposed is very com- plicated and it is obvious that in such a system there is the problem of how to construct a control system that is sufficiently simple and safe. Even if the control system is ever so safe in principle, there may occur a failure in the system, in which case a collision between two cars is possible.

United States patent no. US 6,273, 217 also discloses an elevator solution in which more. than one elevator car moves in the same elevator shaft. The solution proposed in this patent is focused on preventing a possible collision between two elevators on the basis of a program. If a risk of collision appears, one of the elevator cars is moved to give way to the other one. In this case, too, the problem is expressly a risk of collision, because if the program fails or a program error occurs, it is always possible that two elevators traveling towards each other in the same shaft collide.

The object of the present invention is to overcome the above-mentioned drawbacks and achieve an economical, reli- able, safe and well working elevator system for high-rise buildings, in which elevator system one or more elevator cars move in the same shaft independently of the each other. Another object is to arrange the use of elevators so as to achieve a good transport capacity and efficient utilization of building space. A significant aim is to ap-

ply an elevator solution without machine room known in it- self to create a more efficient elevator system for high- rise buildings. These objects and aims of the invention may be distinct from each other or appear as combinations in respect of the inventive solutions described below and the advantages achieved by these solutions.

In simplified terms, it can be stated that the invention concerns passenger guidance and synchronization of the control of elevator groups in an arrangement where eleva- tor groups without machine room are installed one above the other in the same shaft with a shuttle elevator group feeding traffic from sky lobbies to local elevator groups without machine room. The shuttle elevators must be filled uniformly at the entrance floor so as to minimize the num- ber of times the shuttle elevators stop. In this way, a high transport capacity of the shuttle elevators is main- tained and the number of shuttle elevators required is small. If the shuttle elevator group consists of double- deck elevators, the upper and lower cars should be loaded evenly at the main entrance floor. The guidance provided in the main lobby should be simple and coherent so that people will learn to find the right elevator and/or the right passenger compartment of an elevator car. The con- nections from sky lobbies to local groups should be clearly defined and the shuttle elevators should serve each local group equally. However, the object or aims of the invention are not intended to be limited to this sim- plification, nor is the inventive content disclosed in the present application necessarily intended to be limited to the expression appearing in the claims below, but it may be possible to present the inventive content in a form wider or otherwise differently defined than in the claims

below.

The features characteristic of the invention are disclosed in claim 1. Different embodiments are characterized by what is disclosed in the other claims. The embodiments of the invention do not exclude each other ; instead, in order to achieve some advantages, the features of one embodiment may be included in another embodiment as appropriate.

The solution of the invention has the advantage of allow- ing simple solutions to be used to achieve a reliable and safe elevator system that guarantees a good transport ca- pacity in high-rise buildings and makes it possible to save expensive floor area. The space saving is easily 20 percent or even over a third of the space otherwise needed by the elevator system of the building. Thus, in an advan- tageous case according to the invention, the elevator shaft space required for the elevator system of a sky- scraper is two thirds of the space needed in solutions conventionally used, but nevertheless at least the same capacity is achieved as in prior-art solutions. Space sav- ings are achieved both on the lower floors, where the saved space is particularly valuable, and. in higher parts of the building. For example, if the space taken up by eight elevator shafts placed side by side is saved, in a skyscraper this will mean in regard of these elevator shafts, taking the lobby spaces saved into account as well, that the space saving per floor is easily about 150m2, which space thus saved from elevator use can be used as salable or rentable floor area.

The elevator cars of local groups move independently of each other in the same shaft and they never collide be-

cause the hoisting ropes of different elevator cars do not overlap with each other in the vertical direction and it is therefore impossible for the elevator cars to enter into each other's traveling range.

In earlier solutions comprising one or more sky lobbies, generally the building height in the case of two sky lob- bies has been 300-500 m and there have been several local groups starting from the each sky lobby. Now, in a primary preferred solution, only one local group starts from each sky lobby or defined lobby area in up-peak traffic condi- tions, and the local groups are correspondingly fed by a shuttle elevator traffic flow directed to the destination floors of only one local group. The local groups are packed as a continuum in the same shaft from each sky lobby. The feeding shuttle elevator group has more stop- ping floors than a traditional shuttle elevator group and the situation is challenging in respect of sufficiency of capacity and passenger guidance. By using this solution, it is possible to obtain about 30 % or even over 40 % more rentable floor area as compared to a conventional sky- scraper solution, which conventional skyscraper solution e. g. in a building having about 50 floors comprises three elevator groups departing from the main lobby and assigned to serve one low-rise zone, one mid-rise zone and one high-rise zone.

An advantageous solution is one in which the local eleva- tors departing in upward and downward directions from sky lobbies are separated in the sky lobbies in specific lobby areas, and in which these lobby areas are served by dif- ferent shuttle elevators or different passenger compart- ments of shuttle elevators, for example in such manner

that the base floor of an up-going local elevator group is the floor served by the upper passenger compartment of a double-decker elevator car and the base floor of a down- going local elevator group is the floor served by the lower passenger compartment of a double-decker elevator car. In this way it is easy to obtain a solution in which the guidance in the entrance lobby to the shuttle eleva- tors or shuttle elevator passenger compartments feeding the local groups is clear and easily perceivable. This also makes it possible to optimize the capacity of the shuttle elevator group for the incoming traffic coming from the main lobby. If additionally the departure areas of shuttle elevator feed traffic intended for upwards and downwards traveling local groups from different sky lob- bies are defined as separate areas in the entrance lobby, still more efficient transportation is achieved, which will be evident especially during heavy incoming traffic.

This advantage is so significant that it amply compensates for the circumstance that some passengers will first have to travel up on a shuttle elevator and then come down on a local group elevator to their destination floor, i. e. to travel a distance that is somewhat longer than the height difference between the departure floor and the destination floor. If the passenger is transported in up-peak incoming traffic conditions via the shortest route in the upward direction only, the shuttle elevators feed the lowest level of the local groups. The number of times the shuttle elevators have to stop is therefore increased in relation to the passenger flow transported, in other words, the ef- ficiency of the shuttles may consequently be somewhat lower, but the passenger has a clearer feeling of travel- ing towards his destination floor. By reserving certain shuttle elevators of the building in an up-peak situation

and possibly at other times as well for serving only the incoming traffic at certain floors belonging to local groups and in down-peak situations for serving outgoing traffic, it is possible to achieve a significant saving of floor area and at the same time a saving of building space as well. The space thus saved can be used in the building for other purposes, generally sold or rented as business, office or residential space or the like. Even though such additional space leads to a somewhat increased need for elevator capacity, the total effect is economically advan- tageous. In respect of space utilization, the solution achieved by the invention, in which efficient utilization of shaft space is possible without elevator shafts located in upper parts of the building except directly above the elevator shaft below them, is very desirable from the point of view of construction engineering.

In respect of control and structure, the loading of the shuttle and local elevators is balanced, if necessary by using a destination call solution, allowing optimal trans- portation system ratings relative to the transport capac- ity to be achieved. Especially in structures and situa- tions where it is possible to choose the one of the com- partments of a multi-deck elevator car that can serve a given local group, it is favorable to use optimization based on destination floor calls.

The transport capacities, intervals of shuttle elevator groups should fulfill general requirements and in multi- deck solutions the loading of the cars should be uniform, and clear passenger guidance must be provided both on the main entrance floor and on the sky lobbies. Inter-floor traffic should be synchronized so that a connection exists

from each local group to the other local groups either via a local group or a shuttle elevator group. If the shuttle elevator has a multi-deck car, the traffic between the floors in sky lobbies can be taken care of by loading sev- eral decks simultaneously to serve different floor areas.

Simultaneous loading of the passenger compartments of the elevator car increases the transport capacity and de- creases the area required by the shuttle elevators. If different passenger compartments are loaded by turns and the passenger compartment does not stop at the local group desired by the passenger, one solution for handling the internal traffic is to add extra local groups serving the sky lobbies. The number of floors served by the mini- groups should be at least equal to the number of decks in the shuttle elevators. The floor heights in the building may be equal if the floors served by the local elevator groups are interlaced in a staggered manner. When the op- eration of the shuttle and local elevators is synchronized so as to provide access from each intermediate floor to the floor range served by another elevator group either via a local elevator group or a shuttle elevator group in such manner that inter-floor traffic does not cause unnec- essary stops of the shuttle elevators, because such stops consume transport capacity and increase the size of the shuttle group. In the case of multi-deck shuttle eleva- tors, in some cases an extra elevator or a small elevator group is added to the sky lobbies to serve them. Constant floor heights can be maintained in the whole building by synchronizing the floors served by the elevators within the local elevator group.

In the following, the invention will be described in de- tail with reference to embodiment examples and the at-

tached simplified drawings, wherein Fig. 1 presents a prior-art elevator system as a simpli- fied diagrammatic illustration seen from the front of the elevators, Fig. 2 presents an elevator system applying the inven- tion as a simplified diagrammatic illustration seen from the front of the elevators, Fig. 3 presents a magnified view of a sky lobby in the elevator system applying the invention presented in Fig. 2, seen as a simplified diagrammatic il- lustration from the front of the elevators, Fig. 4 presents a sky lobby corresponding to Fig. 3 as a simplified diagrammatic view seen from above, Fig. 5 presents an elevator shaft serving individual floors in the elevator system applying the inven- tion and the elevator cars in it at a sky lobby in side view and sectioned along line V-V in Fig.

4, Fig. 6 presents an elevator shaft serving the sky lob- bies in the elevator system applying the inven- tion and a double-deck elevator car in it at a sky lobby in side view and sectioned along line VI-VI in Fig. 4, and Figures 7A, 7B, 7C, 7D, 7E, 7F, 7G diagrams illustrating different alternatives of application of the in- vention for implementing the elevator system of a 48-floor building.

The solution presented in Fig. 1 represents the above- mentioned prior-art elevator system for high-rise build- ings. Let us consider for example a 45-floor building with fifteen floors in each zone. The number of floors in each

zone is determined by the car size and speed of the eleva- tors used. The system comprises three different vertical zones, so it is necessary to have three different sets 1, 2,3 of elevator shafts, of which shaft set 1 forms the lowest zone, where e. g. a group of eight elevators serves all fifteen floors from the ground floor 9 to the topmost floor 10 of the zone. Fig. 1 shows the elevator doors of four elevators only on the ground floor 9 and on the top- most floor 10 of the zone. Within this zone, the elevators can stop at all floors.

The second zone in the prior-art elevator system is a so- called mid-rise zone, which may also comprise a group of eight elevators installed in a separate set 2 of shafts.

This group only serves the ground floor 9, the first sky lobby 8, which in the solution according to the example is located on the fifteenth floor of the building, and all floors upwards from this floor up to a second sky lobby 8a, which in the solution presented in the example is lo- cated on the thirtieth floor of the building. The eleva- tors in shaft set 2 never stop within the zone 5 of the fifteen lowest floors except at the ground floor. If these elevators do not have a so-called express function, they do not admit passengers into the elevators in shaft set 2 from the ground floor 9 at all but only travel within the area 4 of shaft set 2. In this case, no doors are provided on the ground floor 9 for the elevators in shaft set 2.

Thus, a passenger which wants to reach one the floors in zone 4, e. g. floor 20, must first take an elevator in shaft set 1 and ride on it to transfer floor 10 and then move along sky lobby floor 8 into the elevator lobby 10b of zone 4 and then continue his trip on an elevator in zone 4 to reach floor 20.

The high-rise zone in the prior-art elevator system is served by an elevator group in shaft set 3. The elevators in this group do not stop the floors 7 within the low-rise and mid-rise zones at all, but they either always travel only between the floors in the high-rise zone 6, e. g. floors 31-45, or they are provided with an express func- tion and also travel from the ground floor 9 directly to the second sky lobby 8a, where the lowest floor llb of the high-rise zone is located. If no express function is pro- vided, passengers going to the floors in the upper zone 6 must travel by the route shaft 1, first sky lobby 8, area 4 of shaft set 2, second sky lobby 8a, zone 6 of shaft set 3. Fig. 1 shows only the lowest floor 9, 10b and llb and the topmost floor 10,11 and 12 of each zone. The draw- backs of this system were described above.

Figures 2-6 illustrate an elevator system applying the in- vention. By reserving certain shuttle elevators for serv- ing traffic to certain local groups and providing appro- priate passenger guidance, a considerable saving of floor area is achieved. In this system, the separate set 1 of elevator shafts for the low-rise zone presented in Fig. 1 as well as all the elevator lobbies of these floors have been left out altogether. The system comprises only two sets of elevator shafts. According to the example, the first shaft set 13 comprises eight elevator shafts, each of which accommodates an elevator provided with a so- called double-deck elevator car 21 and having a speed at least as fast as or faster than the elevators traveling elevator shaft set 14. The ground floor 9 is provided with an escalator arrangement 20 that passengers can use to as- cend to and descend from a second ground floor level 9a.

In the lower part 15 of elevator shaft set 13 there is no access to the elevator cars except from the ground floors 9 and 9a and from elevator lobbies 10 and 10a of the first sky lobby 8. Similarly, in the upper part 16 of elevator shaft set 13 there is no access to the elevator cars ex- cept from the elevator lobbies 10 and 10a of the first sky lobby and from the elevator lobbies 11 and lla of the sec- ond sky lobby 8a. In the case of the example, the first elevator shaft set 13 extends from the ground floor to a height of about 2/3 of the total height of the building, in other words, in a 45-floor building the second sky lobby 8a in the upper part of the first shaft set com- prises floors 30 and 31 of the building and correspond- ingly the first sky lobby placed midway between the ends of the first shaft set comprises floors 15 and 16 of the building.

The second elevator shaft set 14 extends as a substan- tially continuous structure from the ground floor 9 of the building to the height of the whole building, i. e. to the topmost floor 45, which is represented by elevator lobby 12. The second elevator shaft set 14 consists of three substantially identical zones placed one above the other.

The shafts in these zones are hereinafter referred to as local shafts 17,18 and 19. Each local shaft is substan- tially identical in cross-section and each local shaft ac- commodates one elevator car 22 serving all floors com- prised in the local shaft. Thus, in the system presented in the example, each elevator shaft in shaft set 14 accom- modates three elevators one above the other, each one in a separate local shaft. In this context, elevator'means at least the elevator car 22 together with the machine 23 and elevator ropes 24. The elevators in the local shafts are

slower or at most as fast as the so-called shuttle eleva- tors in shaft set 13.

The first and second elevator shaft sets are connected to each other via the two two-floor sky lobbies. The first sky lobby 8 is at a height of about one third of the total building height, in other words, in the example it com- prises floors fifteen and sixteen with elevator lobbies 10 and 10a. Similarly, the second sky lobby 8a is located at a height of about two thirds of the total height of the building and comprises in the example floors thirty and thirty-one with elevator lobbies 11 and lla. Each sky lobby is provided with an escalator arrangement 20 to al- low passengers to move from the lower floor of the sky lobby to the upper floor or vice versa.

Thus, the first and second sky lobbies 8 and 8a each com- prise an upper and a lower transfer floor in such manner that each lower transfer floor, which also include eleva- tor lobbies 10 and 11, is the topmost floor level for the elevator car 22 coming to it from below and departing downwards from it in local shafts 17 and 18. Correspond- ingly, each upper transfer floor, which also include ele- vator lobbies 10a and lla, is the lowest floor level for the elevator car 22 coming to it from above and departing downwards from it in local shafts 18 and 19.

Although the number of parallel elevator shafts selected in this example is eight, in the following the structure of only one shaft in the second elevator shaft set 14 will be described. The other shafts are identical to the one described. In its basic structure, each shaft is continu- ous, extending from the ground floor 9 to the topmost

floor of the building if necessary, where elevator lobby 12 is located. In each shaft there are more than one local shaft 17,18 and 19 one above the other, and each local shaft accommodates one elevator with an elevator car 22 serving the floors comprised in the local shaft in ques- tion. Thus, the system described in the example comprises three local shafts 17,18 and 19 placed one above the other, each of which accommodates one elevator car. All the elevator cars in the same shaft are substantially identical and are disposed in substantially the same ver- tical plane one above the other.

Fig. 5 is a more detailed illustration showing how the elevator cars 22 are disposed independently of each other one above the other in the same shaft. Here the elevator car 22 in the middle local shaft 18 stands at its lowest position in elevator lobby 10a on the upper floor of sky lobby 8. Below the elevator car is a framework of support- ing beams 25 serving as the shaft bottom of the local shaft 18 and additionally provided with a strong steel wire net to stop any falling objects in this part of the shaft. The vertical distance between the supporting beam framework and the lowest position of the elevator car 22 has been fitted to be such that the prescribed dimensions of the space below the elevator car are obtained. In addi- tion, fixed buffers for stopping the elevator car 22 on a buffer are mounted on the supporting beam framework 25 or on the wall of the lower part of the local shaft. The buffers are not shown in the figures.

Correspondingly, placed at the upper end of the lower lo- cal shaft 17 below the supporting framework 25 is the ele- vator machine 23 driving the lower elevator car, and the

elevator ropes 24 passing around the traction sheave of the machine are fastened to the elevator car 22 in a suit- able manner. In the figure, the lower elevator car 22 is shown in a local shaft 17, in its upper position at sky lobby 8, so it is standing at elevator lobby 10 on the lower floor of the sky lobby. The elevator machines 23 of all the elevators in the same shaft are mounted in a cor- responding way in the upper part of each local shaft 17 placed one above the other. Thus, in the solution pre- sented in the example, there are also three elevator ma- chines 23 in each shaft, and no machine rooms are needed for the elevators in the local shaft 17. Each local shaft is additionally provided with a counterweight, which is shown partly in shaft 17. When the elevator car 22 is in the upper part of the shaft, the counterweight is in the . lower part and vice versa.

The elevator machine 23 is of a gearless type and substan- tially flat, so it can be secured e. g. to an elevator guide rail or to a shaft wall in the space between the elevator car 22 and the shaft wall. In this way, the ele- vator cars 22 can easily be made independent of each other, because the elevator ropes of different elevators do not overlap with each other in the vertical direction in any part of the shaft.

Fig. 6 presents correspondingly a simplified view the ele- vator car 21 moving in the elevator shafts of the first shaft set 13. In this case, an elevator machine is pro- vided at the upper end of each shaft, and the elevator car 21 is suspended on the ropes 27 of the machine. The upper and lower cars of the elevator car 21 are fastened to- gether by means of fastening elements 26 in such manner

that, when the upper car is at the upper floor of the first sky lobby 8, the lower car is correspondingly at the lower floor of the same sky lobby. The same also applies when the elevator is at the second sky lobby 8a or at the ground floor 9.

The ground floor and the sky lobbies are provided with clear guiding signs for passengers, showing from which level each floor can be reached. Now if we suppose that a passenger is going to floor 20, he will see on the ground floor a guide indicating that the floor in question can be reached by using elevators departing from the ground floor 9. The passenger therefore enters the lower car of the double-deck elevator car 21 at the ground floor 9 and as- cends on the elevator of shaft set 13 to the second sky lobby 8a, where he leaves the elevator in lobby 11 and walks in the sky lobby to an elevator car 22 of shaft set 14, which takes him downwards from floor thirty to floor twenty. If the passenger is going to floor fifty, on the ground floor he will first use an escalator to ascend to the upper floor 9a, from where he will travel in the upper car of elevator car 21 to sky lobby 8a and from there fur- ther via elevator lobby lla to his destination floor on an up-going elevator of shaft set 14.

Figures 7A, 7B, 7C, 7D, 7E, 7F, 7G are diagrammatic repre- sentations of alternative embodiments of the invention in the case of a 48-floor building. The upwards or downwards pointing arrows in the figures indicate the direction of departure of local group elevator cars from a sky lobby or main lobby floor. Elevators without machine room are in- stalled one above the other as local elevators in the lo- cal shafts and the shuttle elevators are installed in

shuttle elevator shafts. The local elevator shafts are ei- ther continuous shafts extending from bottom to top and accommodating several elevators or they are shafts placed one above the other and containing a single elevator.

Preferably the shuttle elevators, which are express eleva- tors, are provided with multi-deck elevator cars in which the elevator car comprises two, three or even more passen- ger compartments one above the other. A double-deck eleva- tor car is relatively flexible in use and it already pro- vides a considerably improved shuttle elevator transport capacity as compared to a single-deck elevator car. In the local groups, safety distances need to be provided above and below the paths of the elevator cars at the transfer floors, which can be achieved by making the sky lobby floors higher than the other floors in the building, for example by using an inter-floor distance of six meters in- stead of four meters or by leaving one floor between local elevators. If one floor is left between local elevators, then it may be necessary to provide in the sky lobby area a low-rise elevator to take care of traffic between the sky lobby floors, but on the other hand such a solution favors the use of a three-deck elevator car.

In up-peak traffic conditions, the load of the elevator cars can be equalized in many ways. For example, in the elevator system illustrated in Fig. 7A, passengers are guided on the ground floor to the cars of multi-deck ele- vators in such manner that the elevators are assigned to zones such that they will only stop at every second sky lobby, from where the elevators depart upwards from the upper sky lobby and downwards from the lower sky lobby.

The guiding sign is shown in the figure in the area of the entrance lobby and the sky lobbies. In this diagram, the

shuttle elevator groups are presented as a wider area and the local groups as a narrower area, but the width or nar- rowness in itself has nothing to do with the width of the corresponding elevators. The guiding information for pas- sengers is visibly shown in the figure and it can be dis- played in the entrance and sky lobbies via fixed and/or variable displays and inside the elevator car via variable displays. The solution presented in Fig. 7B very much re- sembles the solution presented in Fig. 7A, but in this case one shuttle elevator group has been divided so that some of the elevators serve upper sky lobby areas while some of them serve lower sky lobby areas. Such a division can advantageously be designed to be permanent in respect of use of the building, in which case it is possible to make the elevator shafts of the elevators feeding the lower sky lobby areas lower than the elevator shafts of the elevators feeding the upper sky lobby areas. The ca- pacity of the shuttle elevator group in Fig. 7A and 7B can be optimized for incoming traffic coming from the main lobby and the guidance directing passengers to local groups is clear. In Fig. 7B, the shuttle elevator group has been divided in half, one half serving the lower sky lobbies while the other half serves the upper sky lobbies.

Fig. 7C presents a solution where passengers are guided on the entrance floor to the cars of multi-deck elevators in such manner that the elevators always depart upwards from a sky lobby. In this case, the shuttle elevators stop at each sky lobby, but they only unload one car at a time.

Guidance is so implemented that passengers are guided to that passenger compartment of an elevator car that feeds the corresponding local group. In such a solution the shuttle elevator group has to be somewhat larger than in

the cases illustrated in Fig. 7A and 7B.

Fig. 7D presents a solution where the up-peak transport capacity has been increased in relation to the solution of Fig. 7C by dividing the shuttle elevator group in two parts. Of course the group can be correspondingly divided into several zones, especially if the system comprises a large number of elevators. In inter-floor traffic a shut- tle elevator can stop at all sky lobby floors, allowing local groups to be loaded from both upper and lower floors.

In such an elevator system it is very convenient to use destination control to equalize the load, in other words, different elevator cars are filled by utilizing informa- tion regarding the passengers'destination floors, ob- tained from the passengers either via a call device or in other ways before they enter an elevator car. Using desti- nation control, people can be guided to shuttle elevators in such manner that each elevator will stop as few times as possible. Because in this case the control is based on knowing the elevator passengers'destinations before they enter an elevator car, the passengers can be effectively guided to different elevator cars according to the optimi- zation criterion currently valid in each situation. There- fore, rough floor division displays are not necessarily needed on the main entrance floor. During incoming peak traffic, a destination floor call station (DCS call sta- tion) placed in the entrance lobby provides guidance indi- cating the elevator car and the place. Passengers are loaded on local elevators by transporting them to a sky lobby where a shuttle elevator traveling in the appropri- ate direction is already stopping. When destination floor

calls are used, if such a call is issued across an eleva- tor group, the person will be taken to a sky lobby to which is coming a shuttle elevator which is traveling in the appropriate direction and which may already have been assigned a stop at the sky lobby for the destination floor. In this way, the number of stops is reduced and the performance and capacity of the system increased. In the solutions presented in Fig. 7C and 7D, passengers depart- ing from the main lobby can always travel upwards first on a shuttle elevator and then on a local elevator.

Figures 7E and 7F present solutions where the floor height of the sky lobbies in the building is small, i. e. gener- ally the same height as the adjacent floors. Thus, if the building has standard height floors or the sky lobby is otherwise low, then the elevators can be interlaced within the elevator group in a staggered manner such that one floor is left between the elevator of the lower local group and the elevator of the upper local group, in which case it is not necessary to have a larger distance between floors. The upwards and downwards going local groups are adapted to the passage of the shuttle elevators. In the main entrance lobby, the shuttle elevators are fixedly as- signed to different zones to feed corresponding upwards and downwards going local groups. Inside the shuttle ele- vator, a car display shows the floors to be served. For extension floors, a special call button is needed, or in the case of destination control the service works without special call buttons. In the case of Fig. 7E, all floors are spaced by equal distances, requiring staggered inter- lacing in all sky lobbies, and Fig. 7F presents a solution where every second sky lobby has larger floor-to floor distances.

Fig. 7G presents a typical traffic arrangement in the ele- vator system of a building for inter-floor traffic occur- ring as a prevailing traffic type at other times than in- coming and outgoing peak traffic hours.

It is obvious to the person skilled in the art that the invention is not limited to the examples described above, but that it may be varied within the scope of the claims presented below. Thus, for example, the elevator machines may be placed only partly in the elevator shafts, e. g. in such manner that substantially only the traction sheave is in the elevator shaft while the rest of the elevator ma- chine is in a suitable shaft recess or equivalent. An es- sential point is that a separate machine is provided for each elevator in the shaft, the machine being placed near the upper or lower end of the shaft in which the elevator car in question moves. Likewise, the number of zones dis- posed one above the other is not necessarily three but varies according to building height, volume of transporta- tion required and selected elevator properties. These properties include the speed and size of the elevator car.

It is preferable to choose the heights of the shafts needed in such a way that a double-deck elevator car 21 coming to the topmost sky lobby can unload passengers for both upward and downward connections.

The fact that the passenger traffic flow of the shuttle elevators is guided in up-peak conditions to certain local elevators naturally does not stop the passengers from pro- ceeding against the guidance, but in respect of smoothness of the passenger's trip, the elevator system does not en- courage passengers to depart from the guided traffic flow,

rather on the contrary. In other words, departing from the guided route leads to a solution impractical for the pas- sengers, although such departure may sometimes be neces- sary if the destination floor wanted by the passengers is changed during the journey.

In buildings of different heights, the ratio of sky lob- bies to local shafts may vary. In addition, in buildings higher than in the example described above, the number of sky lobbies may be more than two as in the example. Like- wise, the height of the shafts may vary according to the shape of the building and the space in it or due to other reasons, e. g. the speed of the local elevators.