Abstract:
An elevator system comprises at least two independently operable elevator cars in each of a plurality of elevator shafts within a building. The elevator system comprises at least one first elevator shaft having a lower first and a lower second region, where a first elevator car moves within the lower first region of the first elevator shaft and a second elevator car moves within the lower second region. The first and second elevators are moveably controlled independently of each other within the first shaft. The system also includes at least one second elevator shaft having an upper first and an upper second region, where a third elevator car moves within the upper first region of the second elevator shaft and a fourth elevator car moving within the upper second region. The third and fourth elevator cars also are moveably controlled independently of each other.

Description:
[0001]    This is a divisional of U.S. patent application Ser. No. 11/207,539 filed on Aug. 19, 2005, the disclosure of which is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to systems and methods of deploying elevator systems, in particular, the deployment of a plurality of deployment schemes associated with twin elevator systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    In multi-story buildings, one of the main objectives is to efficiently transport passengers to various floors using an elevator system. In designing, developing, and deploying elevator systems, particular attention should be paid to the portion of the building core that is dedicated to the elevator system. For example, as the number of elevator shafts are increased to meet the demands of higher buildings, maximizing real estate space as a commodity is also a main concern that must be addressed. Therefore, the object is to try and minimize the required number of elevator shafts that are deployed within an elevator system, while also trying to effectively meet the transportation needs of passengers and freight within the building. For example, a poorly designed elevator system may cause unacceptable delays for passengers trying to reach a desired floor. However, solutions to try and reduce the number of shafts and improve service have included higher elevator travel speeds, shorter door opening/closing times, advanced control systems, express elevators, splitting buildings into zones, etc. These solutions, while relatively successful in addressing some of the challenges, may not be acceptable by the user. These reasons may include a feeling of unease when elevators accelerate, doors quickly closing, or difficulties that may be experienced as the result of using a complicated system, where passengers may have to change one or several times to get to a desired floor. 
         [0004]    Despite the mentioned optimization measures, it is evident that the largest part or portion of the elevator shaft is not used when the elevator car is in another part of the shaft. One solution attempting to capitalize on this is the double-decker elevator. However, some of the disadvantages of such a system are the large scale drives and power supplies that become necessary for accelerating such a large mass. Also, as the cars are semi-connected, the delays for passengers waiting for other passengers to exit and enter the elevator may be more as a result of two floors being simultaneously served. Moreover, the stories of the building would have to be virtually equidistant, which is an expensive objective to meet in a building. 
         [0005]    It is therefore an object of the present invention to provide an elevator system that is capable of effectively maximizing an elevator shaft by accommodating more than one independently controllable elevator car within a shaft. 
         [0006]    It is another object of the present invention to deploy various elevator schemes using more than one elevator car within each elevator shaft based on different buildings, where each building comprises a different number of floors and elevator shafts. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present invention provides elevator system architectures and methods that employ the use of two elevator cars within a single elevator shaft, where each of the two elevator cars move independently of each other within the shaft. 
         [0008]    An aspect of the present invention according to the present invention provides an elevator system having at least two independently operable elevator cars in each of a plurality of elevator shafts within a building. The system comprises at least one first elevator shaft having a lower first and a lower second region, where a first elevator car moves within the lower first region and a second elevator car moves within the lower second region. Both the first and second elevators are moveably controlled independently of each other, where each elevator car moves independently of the other in the first elevator shaft. The elevator system also comprises at least one second elevator shaft having an upper first and an upper second region, where a third elevator car moves within the upper first region and a fourth elevator car moves within the upper second region. The third and fourth elevator are also moveably controlled independently of each other, where each elevator car moves independently of the other in the second elevator shaft. 
         [0009]    Another aspect of the present invention according to the present invention provides an elevator system within a building that comprises at least one first elevator shaft that includes a lower first and a lower second region. A first elevator car moves within the lower first region and a second elevator car moves within the lower second region, wherein the first and second elevator are moveably controlled independently of each other. At least one second elevator shaft has a lower sky lobby and an upper sky lobby separated from the lower sky lobby by a plurality of mid-level floors, whereby a third elevator car moves between a ground floor of the building and the lower sky lobby, and a fourth elevator car moves between the ground floor and the upper sky lobby. The third and fourth elevator are also moveably controlled independently of each other. 
         [0010]    Yet another aspect of the present invention provides an elevator system having two elevator cars within each elevator shaft for providing goods and passenger transportation to a plurality of floors of a building. The elevator system comprises at least one elevator shaft comprising a virtual landing region located above a top floor of the plurality of floors of the building. A goods elevator car moves within the at least one elevator shaft between a basement floor and the top floor associated with the plurality of floors. A passenger elevator car moves within the at least one elevator shaft between a ground floor associated with the plurality of floors and the virtual landing, wherein the passenger elevator car moves into the virtual landing for allowing accessibility of the goods elevator car to the top floor. The goods elevator car and passenger elevator car are moveably controlled independently of each other within the at least one elevator shaft, whereby each elevator car moves independently of the other in the at least one elevator shaft. 
         [0011]    According to another aspect of the present invention, an elevator system comprises two elevator cars within each elevator shaft for passenger transportation to a plurality of floors of a building. The elevator system further comprises at least one elevator shaft comprising a first region and a second region, where the first region extends from a ground level to a plurality of sub-ground levels. The second region extends from the ground level to a top floor of the building, where a first and a second elevator car move within the at least one elevator shaft. The first elevator car moves within the first region and the second elevator car moves within the second region, wherein the first and the second elevator cars are moveably controlled independently of each other within the at least one elevator shaft. 
         [0012]    According to yet another aspect of the present invention, a method of operating an elevator system comprises a first and a second independently operable elevator car within each elevator shaft within a building. The method comprises the steps of assigning the first elevator to operate within a first region of the elevator shaft, and assigning the second elevator to operate within a second region of the elevator shaft, where the second region is located above the first region. The first and the second elevator car are loaded from a ground floor level, where the loading of the second elevator car from the ground floor is controlled by moving the first elevator below the level of the ground floor to a lower level zone. 
         [0013]    In accordance with another aspect of the present invention, a method is provided for operating an elevator system comprising a first and a second independently operable elevator car within each at least one elevator shaft of a building. The method comprises the steps of providing passenger transportation between a ground floor level and a top floor of the building using the first elevator car within the at least one elevator shaft. Also provided is passenger transportation between a sub-ground floor level and a top floor of the building using the second elevator car within the at least one elevator shaft. The loading of the first elevator car from the top floor is controlled by moving the second elevator above the level of the top floor to a virtual landing region. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where the lower floors are serviced by a first group of elevator cars, and the upper floors are serviced by a second group via an express zone. 
           [0015]      FIG. 2  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where the upper floors are serviced by two shuttle cars operating within the same elevator shaft. 
           [0016]      FIG. 3  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where an elevator motion-free zone is established within each shaft. 
           [0017]      FIG. 4  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where the upper floors are serviced by double deck shuttles for transporting passengers to lobbies that provide access to the upper floors that utilize the two independently moving elevator cars operating within each elevator shaft. 
           [0018]      FIG. 5  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where an upper floor virtual landing is provided. 
           [0019]      FIG. 6  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where a lower ground level virtual landing is provided. 
           [0020]      FIG. 7  illustrates an elevator system deployment scheme employing two independently moving elevator cars operating within each elevator shaft according to an aspect of the present invention, where one of the two independently moving elevator cars services sub-ground level floors, and the other elevator car accordingly services the floors above ground level. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]      FIG. 1  illustrates an elevator system deployment scheme  100  employing two independently moving elevator cars (Twin Cars) operating within each elevator shaft according to an aspect of the present invention. The system  100  according to the present invention represents a zoned twin elevator system. Each elevator car or lift operates within an elevator shaft, where each shaft is designated by a lift number  102  (e.g.,  1 - 12 ). Elevator shafts  1 - 12 , as indicated by  104 , are illustrated at the bottom of deployment scheme  100 , where a first group of elevator shafts, indicated by  106 , provide transportation services to a first region of floors within a building (e.g., floors  1 - 20 ), as indicated by  108 . A second group of elevator shafts, indicated by  110 , similarly provide transportation services to a second region of floors with the building (e.g., floors  21 - 40 ), as indicated by  112 . 
         [0022]    Within the first group of elevator shafts, indicated by  106 , elevator shaft  114  comprises a twin elevator system incorporating two elevator cars that move independently of each other, where independent motion is enabled by providing separate counter weight, rope, and traction drive units for each elevator car. A first region  116  within shaft  114 , denoted by lighter colored circles, indicate the floors (i.e., floors  1 - 10 ) that are serviced by a first elevator car (not shown) associated with the twin elevator cars. A second region  118  within shaft  114 , denoted by the dark colored circles, indicate floors (i.e., floors  11 - 20 ) that are serviced by a second elevator car (not shown). Passengers or uses requiring transportation to floors in the first region  116  may enter the first elevator car on a lower ground level  120  of the building, whereas passengers or users traveling to the floors associated with the second region  118  may enter the second elevator car from the upper ground level  122 . Access between the upper and lower ground levels may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  124 . All the other elevator shafts  126 ,  128 ,  130 ,  132 ,  134  within the first group of elevators  106  are identical to that of elevator shaft  114 , described above. 
         [0023]    The number of elevator shafts designated for each elevator group, and the number of floors associated with each region (e.g., floors  1 - 10  in the first region  116 ) are for purposes of illustration and not limitation, and may vary according to various elevator system design factors (e.g., building size, traffic, etc.). Also, it may be possible to increase the number of elevator cars operating within each shaft to more than two. 
         [0024]    One or more elevator system controllers (not shown) may include various safety and monitoring procedures for ensuring that the independently moving elevator cars sharing a shaft do not come within a certain range or distance of each other for collision avoidance and safety purposes. 
         [0025]    Within the second group of elevator shafts, indicated by  110 , elevator shaft  140  also comprises a twin elevator system incorporating two elevator cars that move independently of each other. A first region  142  within shaft  140 , denoted by lighter colored circles, indicate the floors (i.e., floors  21 - 30 ) that are serviced by a first elevator car (not shown) associated with the twin elevator cars. A second region  144  within shaft  140 , denoted by the dark colored circles, indicate floors (i.e., floors  31 - 40 ) that are serviced by a second elevator car (not shown). Passengers or users requiring transportation to floors in the first region  142  may enter the first elevator car on a lower ground level  120  of the building, whereas passengers or users traveling to floors associated with the second region  144  may enter the second elevator car from upper ground level  122 . As previously described, access between the upper and lower ground levels may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  124 . All the other elevator shafts  146 ,  148 ,  150 ,  152 ,  154  within the second group of elevators  110  are identical to that of elevator shaft  140 , described above. The second group of elevator cars  110  comprise a express zone  158  over which the elevator cars do not stop until the upper region floors (i.e., floors  21 - 40 ) have been reached. 
         [0026]    Use of two elevator cars within each shaft, and the provision of an express zone  158 , reduces the number of elevator shafts required in comparison to systems employing single elevator cars operating within each shaft for a given traffic or utilization factor. The express zone facilitates an expedited service for passengers wishing to be transported to the upper floors of the building, while simultaneously providing the advantages of multiple elevator cars within each shaft. 
         [0027]      FIG. 2  illustrates an elevator system deployment scheme  200  employing two independently moving elevator cars (Twin Cars) operating within each elevator shaft according to another aspect of the present invention. The scheme  200  according to the present invention represents a hybrid elevator system comprising a twin elevator scheme  202  and a split twin shuttle scheme  204 . Elevator scheme  202  is identical to that of region  106  shown in  FIG. 1 , where shafts  1 - 5 , as indicated by  206 , each include two elevator cars within each shaft for servicing floors  1 - 20 . The split twin shuttle scheme  204  comprises a plurality of shafts  208  (i.e., shafts  6 - 8 ), where each shaft has two elevator cars that travel between a ground level and a lower and upper sky lobby  210 ,  212 . A first elevator car (not shown) transports passengers between a lower ground floor level  222  and the lower sky lobby  210  (lighter colored circles). At the lower sky lobby  210 , the passengers may access a bank of elevators  214  that service the mid-level floors of the building, as indicated by region  216 . Similarly, a second elevator car (not shown) transports passengers between an upper ground floor level  224  and the upper sky lobby  212  (dark colored circles). At the upper sky lobby  212 , the passengers may access another bank of elevators  218  that service the upper-level floors of the building, as indicated by region  220 . 
         [0028]    As illustrated in  FIG. 2 , elevator banks  214  and  218  are accessible from the upper level floors (i.e., floor  21  and  31 , respectively). This provides an advantage where the shafts for these elevator banks  214 ,  218  do not have to extend down to the ground floor level as the elevator cars are operable from their respective sky lobbies. Accordingly, elevator shafts  9 - 12 , indicated by  226 , are not required to extend from floor  21  to the lower ground level  222 . Similarly, elevator shafts  13 - 16 , indicated by  228 , are not required to extend from floor  31  to the upper ground level  224 . This provides an increase in building core space, in addition to providing more efficient elevator traffic management. 
         [0029]    Passengers requiring transportation to lower sky lobby  210  may enter the first elevator car on the lower ground level  222  of the building, whereas passengers traveling to upper sky lobby  212  may enter the second elevator car from the upper ground level  224 . Access between the upper and lower ground levels  222 ,  224  may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  230 . Also, elevator cars associated with elevator shafts  1 - 5 , as indicated by  206 , may be accessed from the lower or upper ground levels  222 ,  224  depending on whether passengers require transportation to the lower level floors, denoted by the lighter colored circles, or the upper floors, as indicated by the dark colored circles. 
         [0030]      FIG. 3  illustrates an elevator system deployment scheme  300  comprising two independently moving elevator cars (Twin Cars) operating within each elevator shaft according to an aspect of the present invention. The system  300  according to the present invention represents a zoned twin elevator system, where each zone has a respective express region therebetween. 
         [0031]    Each elevator car operates within an elevator shaft, where each shaft is designated by a lift or elevator number  302  (e.g.,  1 - 12 ). Elevator shafts  1 - 12 , as indicated by  304 , are illustrated at the bottom of deployment scheme  300 , where a first group of elevator shafts, indicated by  306 , provide transportation services to a first region of floors within a building (e.g., floors  1 - 30 ), as indicated by  308 . A second group of elevator shafts, indicated by  310 , similarly provide transportation services to a second region of floors with the building (e.g., floors  11 - 40 ), as indicated by  312 . 
         [0032]    Within the first group of elevator shafts, indicated by  306 , elevator shaft  314  comprises a twin elevator system incorporating two elevator cars that move independently of each other within the shaft. Independent motion is enabled by providing separate counter weight, rope, and traction drive units for each elevator car. Other known methods known in the art of elevator motion and control may be incorporated to achieve independent movement of the elevator cars. A first region  316  within shaft  314 , denoted by lighter colored circles, indicates the floors (i.e., floors  1 - 10 ) that are serviced by a first elevator car (not shown), and a second region  318  within shaft  314 , denoted by the dark colored circles, illustrates floors (i.e., floors  21 - 30 ) that are serviced by a second elevator car (not shown). As illustrated in the figure, an express region  319  is located between regions  316  and  318 , which expedites the transportation of passengers to the upper floors of the elevator cars operating within the first group of elevator shafts indicated by  306 . The express region  319  also simplifies the safety and control capabilities of the elevator control system. This is facilitated by the physical separation between any two elevator cars operating in their designated regions within each shaft. For example, there is a ten floor separation between the first elevator car operating within region  316  and the second elevator car operating within region  318 . In such a scenario, the closest proximity between the cars operating in regions  316  and  318  is ten floors, which accounts for a relatively safe distance between the cars. If either car violates this distance, either or both elevator cars can be safely closed down using less complex sensor and control programming. 
         [0033]    Passengers requiring transportation to floors in the first region  316  may enter the first elevator car on a lower ground level  320  of the building, whereas passengers or users traveling to the floors associated with the second region  318  may enter the second elevator car from the upper ground level  322 . Access between the upper and lower ground levels may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  324 . All the other elevator shafts  326 ,  328 ,  330 ,  332 ,  334  within the first group of elevators  306  are identical to that of elevator shaft  314 , described above. 
         [0034]    The number of elevator shafts designated for each elevator group, and the number of floors associated with each region (e.g., floors  1 - 10  in the first region  316 ) are for purposes of illustration and not limitation, and may vary according to various elevator system design factors (e.g., building size, traffic, etc.). Also, it may be possible to increase the number of elevator cars operating within each shaft to more than two. 
         [0035]    One or more elevator system controllers (not shown) may include various safety and monitoring procedures for ensuring that the independently moving elevator cars sharing a shaft do not come within a certain range or distance of each other for collision avoidance and safety purposes. 
         [0036]    Within the second group of elevator shafts, indicated by  310 , elevator shaft  340  also comprises a twin elevator system incorporating two elevator cars that move independently of each other. A first region  342  within shaft  340 , denoted by lighter colored circles, indicate the floors (i.e., floors  21 - 30 ) that are serviced by a first elevator car (not shown) associated with the twin elevator cars. A second region  344  within shaft  340 , denoted by the dark colored circles, indicate floors (i.e., floors  31 - 40 ) that are serviced by a second elevator car (not shown). As illustrated in the figure, an express region  356  is also located between regions  342  and  344 , which expedites the transportation of passengers to the upper floors of the elevator cars operating within the first group of elevator shafts indicated by  310 . The express region  356  also simplifies the safety and control capabilities of the elevator control system. This is facilitated by the physical separation between any two elevator cars operating in their designated regions within each shaft. 
         [0037]    Passengers or users requiring transportation to floors in the first region  342  may enter the first elevator car on a lower ground level  320  of the building, whereas passengers or users traveling to floors associated with the second region  344  may enter the second elevator car from upper ground level  322 . As previously described, access between the upper and lower ground levels may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  324 . All the other elevator shafts  346 ,  348 ,  350 ,  352 ,  354  within the second group of elevators  310  are identical to that of elevator shaft  340 , described above. 
         [0038]      FIG. 4  illustrates a yet another hybrid elevator system deployment scheme  400 , which includes two independently moving elevator cars (Twin Cars) operating within each elevator shaft according to another aspect of the present invention. The scheme  400  according to the present invention represents a hybrid elevator system comprising a zoned twin elevator scheme  402 , a split twin shuttle scheme  404 , a double deck elevator shuttle  406 , and an upper and lower zoned twin elevator scheme  408 ,  410 . Elevator scheme  402  is identical to that of scheme  202  illustrated and described in connection with  FIG. 2 , where shafts  1 - 2 , as indicated by  412 , each include two elevator cars within each shaft for servicing floors  1 - 8 . 
         [0039]    The split twin shuttle scheme  404  is identical to that of scheme  204  illustrated and described in connection with  FIG. 2 , and comprises a plurality of shafts  414  (i.e., shafts  3 - 4 ), where each shaft has two elevator cars that travel between a ground level and a lower mid-level and upper mid-level sky lobby  416 ,  418 , respectively. A first elevator car (not shown) transports passengers between a lower ground floor level  422  and the lower mid-level sky lobby  416  (lighter colored circles) via an express zone  417 . At the lower mid-level sky lobby  416 , the passengers may access a bank of elevators  424  that service the lower mid-level floors of the building, as indicated by region  426 . Similarly, a second elevator car (not shown) transports passengers between an upper ground floor level  423  and the upper mid-level sky lobby  418  (dark colored circles) via express zone  417 . At the upper mid-level sky lobby  418 , the passengers may access another bank of elevators  430  that service the upper mid-level floors of the building, as indicated by region  432 . 
         [0040]    As illustrated in  FIG. 4 , elevator banks  426  and  430  are accessible from the mid level floors (i.e., floor  9  and  18 , respectively). This provides an advantage, where the shafts corresponding to these elevator banks  426 ,  430  do not have to extend down to the ground floor level, as the elevator cars are operable from their respective sky lobbies (i.e., floor  9  and  18 , respectively). Accordingly, elevator shafts  5 - 6 , indicated by  426 , are not required to extend from floor  9  to the lower ground level  422 . Similarly, elevator shafts  7 - 8 , indicated by  430 , are not required to extend from floor  17  to the upper ground level  423 . This provides an increase in building core space, in addition to providing more efficient elevator traffic management. 
         [0041]    Passengers requiring transportation to lower mid-level sky lobby  416  may enter the first elevator car on the lower ground level  422  of the building, whereas passengers traveling to upper mid-level sky lobby  418  may enter the second elevator car from the upper ground level  423 . Access between the upper and lower ground levels  422 ,  423  may be provided, for example, by a connecting stair case, a shuttle elevator, and/or an escalator  436 . Also, elevator cars associated with elevator shafts  1 - 2 , as indicated by  412 , may be accessed from the lower or upper ground levels  422 ,  423  depending on whether passengers require transportation to the lower level floors, denoted by the lighter colored circles, or the upper floors, as indicated by the dark colored circles. 
         [0042]    The double deck elevator shuttle scheme  406  illustrated in  FIG. 4  comprises a plurality of shafts (i.e.,  9 - 10 ), as indicated by  440 . Each shaft includes a double deck elevator car (not shown) which comprises a lower deck elevator car coupled to an upper deck elevator car. When the double deck elevator car is at any given floor, the upper deck elevator car concurrently serves the floor immediately above the floor served by the lower deck elevator car. The double deck elevator car associated with each of the plurality of shafts  440 , provides passenger transportation between the upper and lower ground floor levels  422 ,  423 , and a first and second upper-level lobby  442 ,  444 , respectively. 
         [0043]    At the first and second upper-level lobby  442 ,  444 , elevator banks  446  and  448  associated with upper and lower zoned twin elevator schemes  408 ,  410  are accessible. The respective shafts within elevator banks  446  and  448 , each include two independently moving first and second elevator cars (i.e., twin system). Zoned twin scheme  408  comprises a top down zoned twin system, whereby floor region  450 B is serviced by a first elevator car operating within each shaft (i.e., Lift No.  11 - 12 ) and floor region  452 B is, similarly, serviced by a second elevator car operating within each shaft (i.e., Lift No.  11 - 12 ). Zoned twin scheme  410  comprises floor region  450 A, which is serviced by a first elevator car operating within each shaft (i.e., Lift No.  13 - 14 ) and floor region  452 A is, similarly, serviced by a second elevator car operating within each shaft (i.e., Lift No.  11 - 12 ) of the zoned twin system. 
         [0044]    Passengers requiring access to floor regions  450 B and  452 A may access elevator banks  446  and  448  by taking one of the double deck elevator cars (i.e., Lift No.  9  or  10 ) from upper ground level  423  to the second upper-level lobby  444 . Similarly, floor regions  450 A and  452 B may be accessed via elevator banks  446  and  448  by taking one of the double deck elevator cars (i.e., Lift No.  9  or  10 ) from lower ground level  422  to the first upper-level lobby  442 . The upper and lower zoned twin elevator schemes  408 ,  410  are accessed by the double deck elevator shuttle scheme  406  and, thus, provide an efficient means of traffic management, whereby passengers requiring service to the upper floors of the building are transported via express zone  456  to the upper-level lobbies  442 ,  444 . This also enables the elevator shafts within elevator banks  446  and  448  to extent only as far down as the lowest floor for which they provide service. For example, the elevator shafts associated with elevator bank  446  may only need to extend as far “floor  28 ,” which facilitates the use of core building space below this floor (i.e., floor  28 ). Also, the shafts of elevator bank  448  may only need to extend from the top region of the building to “floor  37 .” Hence, the use of core building space below “floor  37 ” is mad made available. The number of floors and elevator shafts (i.e., indicated by lift no.) illustrated in connection with  FIG. 4  are for purposes of illustration and not of limitation. For example, the number of floors and elevator shafts may be increased in accordance with traffic management, elevator system design principles, and/or other factors. 
         [0045]      FIG. 5  illustrates an elevator deployment scheme  500  for providing a combination of goods and passenger transportation according to an aspect of the present invention. In the embodiment of  FIG. 5 , transportation of both goods and passengers is provided by two independently moving elevator cars operating within each shaft, as indicated by  502 . Each elevator shaft comprises a lower and an upper elevator car, where transportation provided by the lower elevator car is indicated by the lighter colored circles and service provided by upper car is identified by the dark colored circles. Transportation between the ground floor level and a floor immediately below the top floor (i.e.,  15   th  floor), as indicated by  504 , is provided by both the upper and lower elevator cars moving within each shaft. Transportation to the basement  506  is provided by the lower elevator car only. Also, transportation to the top floor  508  (i.e.,  16   th  floor) is normally provided by the upper elevator car. However, if a virtual landing area  510  is provided, the upper elevator may move into the virtual landing area  510 , allowing the lower elevator car to service or provide transportation to the top floor  508 . The virtual landing may comprise a location in the hoistway or elevator shaft, where one of the twin elevator cars can be moved in order to make way for the other elevator car operating within the same elevator shaft. 
         [0046]    For illustrative purposes, the lighter colored circles designate the floors that receive transportation services from the lower elevator cars within each of elevator shafts  1 - 6 , defined by  502 . The lower elevator cars may be used as a goods or services elevator. The darker colored circles designate the floors that receive transportation services from the upper elevator cars within each of elevator shafts  1 - 6 , defined by  502 , whereby the upper elevator cars may provide passenger transportation. 
         [0047]    As both elevator cars within each elevator shaft have access to a common set of floors within a building, the minimum permissible safe distance between the upper and lower elevator cars may be a single floor. For example, the lower elevator car may be on the  5   th  floor and the upper elevator car may be directly above it on the  6   th  floor. The control mechanisms for controlling and maintaining a safe distance between the upper and lower elevator cars may depend on the elevator controller system (not shown) and sensory technology (not shown) employed. For example, based on safety and other considerations, a minimum safe distance of two or more floors may be required between the elevator cars. 
         [0048]    The elevator controller may also provide a priority based elevator dispatching process, that assigns a higher priority to passenger transportation relative to goods or services transportation. Therefore, the controller system may ensure that the elevator shafts are mainly free and not obstructed by the lower goods elevator cars during periods when passenger traffic is high (e.g., 5 pm in an office building). 
         [0049]      FIG. 6  illustrates an elevator deployment scheme  600  comprising a zoned twin elevator system according to an aspect of the present invention. The zoned twin elevator is identical to the zoned twin system described and illustrated in connection with  FIG. 1 , accept that deployment scheme  600  comprises a single ground floor level  602  (i.e., no upper and lower ground floor level) and a virtual landing  604  that is located beneath ground level  602 . Each of the elevator shafts, indicated by  606 , include two elevator cars (not shown) independent operating within them. As previously described, each elevator operates within a region or zone. For example, within each shaft (e.g., shaft  612 ), a first elevator car provides transportation between the ground floor  602  and the  10   th  floor of the building, as indicated by region  608 , and designated by the lighter colored circles. Also within each shaft, a second elevator car provides transportation from the ground floor  602  to the upper floors of the building (i.e., floors  11 - 20 ), as indicated by region  610 , and designated by the darker colored circles. 
         [0050]    As illustrated in  FIG. 6 , both the first and second elevator cars may load passengers from the ground level  602 . The first elevator cars operating in region  608  may load passengers from their rear doors and the second elevator cars operating in region  610  load passengers from their front doors. At any given instant, only one of the elevator cars operating within each shaft can access the ground floor  602  for the purpose of loading passengers. If, for example, the second elevator car operating in region  610  is assigned to load passengers from the ground floor  602 , the first elevator car operating in region  608  must be relocated to the virtual landing  604  in order to allow the second elevator to access the ground floor  602 . 
         [0051]    If the first elevator car operating in region  608  is assigned to load passengers from the ground floor  602 , the second elevator car should be operating within region  610  or be located at a minimum safe distance above the first elevator car in compliance with the safety standards and mechanisms in place. 
         [0052]      FIG. 7  illustrates an elevator deployment scheme  700  comprising a zoned twin elevator system according to an aspect of the present invention. Each of the elevator shafts, indicated by  702 , include two elevator cars (not shown) independent operating within them. As previously described, each elevator operates within a region or zone. For example, within each shaft (e.g., shaft  704 ), a first elevator car provides transportation between the ground floor  706  and the top floor of the building, as indicated by region  708 , and designated by the dark colored circles. Also within each shaft, a second elevator car provides transportation from the ground floor  706  to the sub-ground level floors of the building (i.e., floors P 1 -P 4 ), as indicated by region  710 , and designated by the lighter colored circles. The sub-ground level floors, indicated by  710 , may, for example, be parking levels underneath the building. The floor levels located above ground level  706 , may for example, be residential apartments, offices, and/or commercial shopping floors. 
         [0053]    As illustrated and described in connection with  FIG. 6 , elevator deployment scheme  700  comprises a single ground floor level  702  (i.e., no upper and lower ground floor level). Both the first and second elevator cars within each shaft may load passengers from the ground level  702 . The first elevator cars operating in region  708  may load passengers from their front doors and the second elevator cars operating in region  710  (i.e., parking levels) may load passengers from their rear doors. At any given instant, only one of the elevator cars operating within each shaft can access the ground floor  702  for the purpose of loading passengers. If, for example, the second elevator car operating in region  710  is assigned to load passengers from the ground floor  702  for the purpose of transporting them to the parking area, the first elevator car operating in region  708  should remain operating at a minimum safe distance from the second elevator car in region  708 . 
         [0054]    If the first elevator car operating in region  708  is assigned to load passengers from the ground floor  702 , the second elevator car should be operating within region  710  and be located at a minimum safe distance below the first elevator car. By operating two elevators within a single shaft, more efficient use of the elevator shaft and, therefore, more passenger transportation is facilitated. As illustrated in  FIG. 7 , while passengers are being transported to the upper floors, the elevator shaft is simultaneously utilized for transporting our passengers to the parking area. This deployment scheme  700  increases the traffic flow significantly by allowing each of the twin elevator cars to operate in two separate regions  708 ,  710  that have little or no overlap within each shaft (e.g., shaft  702 ). 
         [0055]    In addition to the embodiments of the aspects of the present invention described above, those of skill in the art will be able to arrive at a variety of other arrangements and steps which, if not explicitly described in this document, nevertheless embody the principles of the invention and fall within the scope of the appended claims. For example, the ordering of method steps is not necessarily fixed, but may be capable of being modified without departing from the scope and spirit of the present invention.