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RELATED APPLICATION  
       [0001]     This is a continuation-in-part of co-pending parent application PCT/IL01/00658 in which the U.S. has been designated, filed 18 Jul. 2001, the contents of which are hereby incorporated by reference, itself claiming priority from U.S. application Ser. No. 09/620,228, filed 20 Jul. 2000. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates, in general, to a multi-level, automated parking structure wherein entering vehicles can be automatically transferred by one or more elevators to levels of generally circular, particularly annular construction having vacant parking spaces and wherein means are provide for transferring vehicles from the elevators to the vacant parking spaces and, in reverse, for transferring the vehicles from the parking spaces to the elevators for subsequent retrieval.  
       BACKGROUND OF THE INVENTION  
       [0003]     Automated parking systems are known which are provided with computerized and mechanical means to take control over a vehicle upon its arrival and to park it automatically in an available parking space, the vehicle being later returned to its driver, on demand. Recent developments in computerization and automation have lowered labor costs and rendered these systems speedier and more reliable. Automated parking systems offer obvious advantages over ramped garages, such as a saving in driver time and in fuel consumption, as well as the elimination of noxious fumes. These systems also minimize the dangers of accidents, theft and violence.  
         [0004]     Nevertheless, few automated parking systems have actually been installed or enjoyed financial success, possibly because of high cost but mainly due to their inability to carry out vehicle parking and retrieving rapidly and efficiently enough when many clients are waiting in line, namely their steady throughput is too low and not reliable.  
         [0005]     The prior art contains examples of automated parking structures having successive circular, particularly annular parking levels, none of which, however, have provided a solution for the combined problems of construction costs and rapid vehicle throughput. Such examples are to be found in U.S. Pat. Nos. 5,915,908; 5,851,098; 5,674,040; 5,478,182; 4,039,089, CH 684,203 A5; and European 0445,712-A1.  
         [0006]     Of particular interest is U.S. Pat. No. 5,469,676 which discloses a circular parking garage which includes from two up to five rotating elevators in a central shaft of the parking system. This structure is volume-consuming as the inner diameter of the center, devoted to vehicle transfer, is very large, because of the spatial requirements of a central structural shaft wherein a plurality of rotatable elevators are located.  
         [0007]     Also of interest is the disclosure in JP 4,149,377 of a multilevel parking structure, each level comprising a pair of coaxial rotary parking platforms respectively and independently served by inner and outer elevators. The structure is not provided with any means for ensuring transfer of vehicles from one rotating platform to its coaxial neighbor. Furthermore the location and mode of operation of the elevators do not, for example, offer any back-up provision for the eventuality that the inner elevator fails to function.  
         [0008]     U.S. Pat. No. 6,004,091 discloses a circular parking system using rotatable carousels to transfer vehicles to concentric spaces in a round, special purpose building. A few such carousels act to move the cars vertically and, by rotation of the carousel, also horizontally. Here one carousel is not able to approach the entrance of other levels because another carousel occupies the space at that time. Hence the response time of the system is slow. Also, the center shaft is dedicated to car transfer and therefore the volumetric efficiency of the system is relatively small.  
         [0009]     U.S. Pat. No. 5,024,571 includes a ring of elevators, but each elevator serves only certain parking sites, so that temporary failure of said elevator will prevent exit of vehicles parked in these sites, so that no redundancy is optional. This patent, like many others in the prior art, uses pallets rather than dollies for transferring and storing the vehicles which makes it dependent on a pallet handling system and additional needed space, that further reduce the throughput of such system.  
       SUMMARY OF THE INVENTION  
       [0010]     It is an object of the present invention to provide a new and improved multi-level, automated vehicle parking structure in which at least some of the disadvantages inherent in the prior art constructions are substantially reduced.  
         [0011]     In accordance with one aspect of the present invention there is provided a multi-level, automated vehicle parking structure, comprising: 
    a plurality of horizontal, planar platform assemblies respectively located on a plurality of structure levels; 
        a central air shaft extending vertically through said levels; 
            each assembly comprising a rotary platform surrounding said shaft and rotatable about a vertical axis of rotation extending substantially through said shaft;    
            at least two oppositely directed vehicle elevators vertically and separately displaceable in said shaft and having respective, substantially parallel, base centre lines which are off-radial with respect to said axis of rotation; 
            each of said rotary platforms having defined thereon a plurality of parking spaces arranged in circular array with respect to said axis of rotation and having respective base centre lines off-radially inclined in the same sense with respect to said axis of rotation; 
                said base centre lines of said vehicle elevators and of said parking spaces being substantially tangentially directed with respect to a circle centred on said axis of rotation and of diameter substantially equal to the normal distance between the parallel base centre lines of said vehicle elevators;    
                each rotatable platform being rotatably displaceable so as to bring any selected pair of opposite parking spaces into respective communication with said elevators with the central base lines of said elevators being substantially co-directional with the central base lines of the selected parking spaces;    
            at least one vehicle entry and exit level for selective communication with said elevators for transfer thereto and therefrom respectively vehicles to be parked and to be retrieved; 
            motorised dollies for transporting vehicles from and to said elevators to and from parking spaces on said stationary platform co-directional with said elevators; and    
            drive means for respectively rotatably displacing said rotatable platforms and for vertically displacing said elevators.    
       
 
         [0022]     This provision of the structure with a plurality of centrally located elevatora who centre base lines are not radially directed with respect to the rotational axis of the structure and, their association with off-radially directed parking spaces on the platforms allows for a very significant economy in space in the central air shaft (as compared with the space required to accommodate radially directed elevators). This, together with the possibility of supplementing the central elevators with additional elevators disposed adjacent the outer peripheries of the rotatable platforms radically increases the vehicle throughput capacity of the styructure.  
         [0023]     Preferably, the rotatable platforms are surrounded by coaxial stationary platforms with similarly off-radial parking spaces, motorised dollies being provided for transferring vehicles between each par of coaxial platforms. The outer stationary platform can be of segmented construction with the outer elevators being displaceable in the inter-segmentary spaces.  
         [0024]     It will be appreciated that, the provision, in accordance with this aspect of the invention, of a bank of elevators within the inner periphery of the rotatable platforms and which are off-radially directed and which are designed to communicate with similarly off-radially directed parking spaces on the platforms allowsw for a maximal number of elevators in a minimal spatial region thereby considerably contributing to to an increased vehicle throughput with minimal increase of constructional space.  
         [0025]     In accordance with another aspect of the present invention there is provided 
        a multi-level, automated vehicle parking structure, comprising:     a plurality of horizontal, planar platform assemblies respectively located on a plurality of structure levels;     a central air shaft extending vertically through said levels; 
            each assembly comprising a stationary platform surrounding said shaft and substantially coaxial with said shaft;    
            at least two oppositely directed vehicle elevators separately displaceable in a vertical direction in said shaft and being rotatable as a unit in said shaft about a vertical axis of rotation extending through said shaft, said pair of elevators having respective, substantially parallel, base centre lines which are off-radial with respect to said axis of rotation; 
            each of said stationary platforms having defined thereon a plurality of parking spaces arranged in circular array with respect to said axis of rotation and having respective base centre lines off-radially inclined in the same sense with respect to said axis of rotation; 
                said parallel base centre lines of said vehicle elevators and of said parking spaces being substantially tangentially directed with respect to a circle centred on said axis of rotation and of diameter substantially equal to the normal distance between the parallel base centre lines of said vehicle elevators;    
                said elevators being rotatably displaceable so as to bring the central base lines thereof into respective communication with any selected pair of opposite parking spaces with the central base lines of said elevators being substantially co-directional with the central base lines of the selected parking spaces;    
            at least one vehicle entry and exit level for selective communication with said elevators for transfer thereto and therefrom respectively vehicles to be parked and to be retrieved; 
            motorised dollies for transporting vehicles from and to said elevators to and from parking spaces on said stationary platform co-directional with said elevators, and for return to their respective elevators; and    
            drive means for respectively rotatably displacing said elevators and for their separate vertical displacement.        
 
         [0037]     As distinct from the prior art structures, referred to above, there is the continuing possibility of transfer of vehicles from the inner rotary to the outer stationary platforms and vice versa. Furthermore optimal use of constructional space is achieved when the outer stationary platforms are constructed in segmental form with the elevators vertically displaceable in the inter-segmental spaces or intervals.  
         [0038]     Preferably said vehicle entry and exit level comprises: 
    a rotatable transfer platform having defined thereon a plurality of vehicle transfer locations arranged in circular array with respect to a vertical axis of rotation of said platform; 
        said elevators being vertically displaceable for selective communication with the transfer locations and the parking spaces on the rotatable platforms of each of said levels to convey vehicles to, and to retrieve vehicles from said levels;     a plurality of vehicle entry and exit stations radially distributed about an outer periphery of said rotatable transfer platform, each station being rotatable between vehicle entry and exit positions and an intermediate vehicle delivery and collecting position aligned with a vehicle transfer location;     said rotatable transfer platform being rotatably displaceable so as to bring any selected transfer location thereon into alignment with said station entry and exit position so as to receive a vehicle from or to deliver a vehicle to said station and so as to bring any selected transfer location thereon into alignment with an elevator so as to deliver a vehicle to or receive a vehicle from said elevator; and motorised dollies for transporting vehicles from and to said transfer stations to and from aligned transfer locations of said transfer level; and for transporting vehicles from and to said elevators to and from aligned transfer locations and parking spaces.    
       
 
         [0043]     Such an arrangement allows for a radically increase potential for rapid and effective vehicle throughput especially during peak traffic times.  
         [0044]     In all cases the motorised dollies which are employed to transfer vehicles from and to the elevators and between the rotary and stationary platforms can be of the AGV (Automatic Guided Vehicle) type whilst appropriate computer controlled systems are used to ensure the ready elevator availability and the appropriate positioning of a vacant parking space as well as the control of the motorised dollies. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0045]     In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:  
         [0046]      FIG. 1  is a schematic representation of a multi-level vehicle parking structure in accordance with the invention;  
         [0047]      FIG. 2  illustrates an embodiment of a multi-level parking structure having two elevators installed in a central air shaft serving the inner perimeter of a rotatable parking platform wherein the inner elevators and parking spaces are in non-radial alignment with the center of rotation; all parking places are turned in one tendency from the radial.  
         [0048]      FIG. 3  illustrates an embodiment on which each level of the multi-level structure is a rotary annular platform serviced by a central bank of four elevators with non-radial centerlines operating within a vertical air shaft bordered by the inner periphery of the non-radial parking platform. An additional, outer stationary annular non radial array of parking spaces, receives vehicles from, and returns them to, the rotatable parking platform.  
         [0049]      FIG. 4  illustrates the drive-in, drive-out level of an embodiment according to  FIG. 3  wherein a bank of four non-radial elevators operates within the air shaft of the building, serviced by several turntables to facilitate easy ingress and egress.  
         [0050]      FIG. 5  illustrates an embodiment in which on every level of the multi-level structure is a stationary annular parking platform, with non radial parking places, serviced by a rotating central bank of two elevators operating within a vertical air shaft bordered by the inner periphery of the stationary parking platform.  
         [0051]      FIG. 6  is a plan view illustrating one level of a parking structure for parking vehicles with a rotatable annular parking platform having radially aligned parking spaces. Elevators are spaced at the outer periphery of said rotating platform and additional stationary parking spaces between the outer elevators receive vehicles from, and return them to, the rotatable parking platform.  
         [0052]      FIG. 7  is a plan view illustrating an embodiment of a a multi-level parking structure having a rotatable annular parking platform with elevators at its outer periphery. Additional parking spaces between the outer elevators and an additional inner stationary central annular parking platform, receive vehicles from, and return them to, the rotatable parking platform.  
         [0053]      FIG. 8  illustrates a plan view of the drive-in, drive-out street level of the parking structure of  FIG. 7  serviced by twice as many turntables as the number of elevators.  
         [0054]      FIG. 9  illustrates a parking level in accordance with a further embodiment of the invention;  
         [0055]      FIG. 10  illustrates an entry/exit level of a further embodiment in accordance with the invention; and  
         [0056]      FIG. 11  illustrates an embodiment of the invention that includes a double-decker elevator of adjustable deck heights increases the throughput of the system where there exists separate drive-in, drive-out levels and parking levels of varying heights. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0057]      FIG. 1  shows a vehicle-parking installation generally indicated by  1 . The installation is designed as a circular building with a central vertical axis X. An entry/exit level  3  may be located at ground level as shown in  FIG. 1 . Alternatively, the entry/exit level  3  may be located above or below ground level, in which case, the entry/exit level is accessed by one or more ramps. The parking installation  1  may also have separate entry and exit levels located at different levels in the installation  1 . The entry/exit level  3  is shared by a plurality of parking levels  2  that may be either above, below or partly above and partly below the entry/exit level. In accordance with the invention, each parking level  2  includes one or more circular or annular platforms that are rotatable around the axis X of the installation  1 .  
         [0058]     The installation  1  includes one or more elevator shafts  5  extending vertically through the installation. Each elevator shaft includes an elevator car  9  for transferring vehicles between each of the parking levels  2  and the entry/exit level  3 . The elevator shafts may be located in the center of the installation as shown in  FIG. 1 , or may be located around the periphery of the installation.  
         [0059]     Each parking space in the installation  1  preferably has an associated sensor that determines whether the parking space is occupied or vacant. A change in the status of each space (occupied or vacant) is transmitted in real time to a computer and stored in a database associated with the computer. The sensor may be, for example, an electromagnetic permeability detector planted in each parking space which senses the metallic presence of a vehicle overlying the sensor, to generate a signal which is supplied to the data base of the computer to indicate whether the parking space is free or taken.  
         [0060]     When a vehicle enters the entry/exit level  3  the computer generates a map-giving the existing status of the parking spaces in the facility and determines the closest vacant parking space on the parking levels  2  that elevator. The car is delivered into an elevator car, and the computer then generates a command signal to the elevator car to rise to the parking level  2  upon which the determined vacant parking space is located. Movement of vehicles on the entry/exit level  3  and on the parking levels  2  is by means of motorized dollies, as described in detail below.  
         [0061]     Where a high throughput is desirable, drive-in and drive-out facilities can be Located on two levels, for example, with one being at street level and the other at basement level, accessible by way of a ramp or ramps. During regular operation, drive-in facilities could be in the basement and drive-out at street level, but at peak hours both levels could cooperate to serve either entering or departing vehicles. The two parking levels can be served by a double-decker elevator as described in detail below.  
       First Embodiment  
       [0062]      FIG. 2  shows one embodiment of the parking level  2 , generally indicated by  2   a . The parking level  2   a  includes an annular platform  8  rotatable about the central axis X of the installation. Two elevator shafts  4  and  6  are centrally located in an interior central space  26  of the parking level  2   a . The elevators  4  and  6  share a common wall  10  that lies on a diameter of the parking level  2   a . The elevators  4  and  6  have parallel base centerlines  14   a  and  14   b , respectively, which are off-radial, i.e. neither of which lie on a diameter of the parking level  2   a . The elevator shafts  4  and  6  each have an opening  15   a  and  15   b , respectively, at the parking level  2   a , facing opposite directions. The annular rotatable platform  8  comprises a plurality of parking spaces  20 , having off-radially aligned center base lines, represented by broken lines  14 .  
         [0063]     Transferring a vehicle from an elevator car, for example, the elevator car  9   a  located in the elevator shaft  6 , to a vacant parking space  20   a  takes place at a position wherein the center base line  24  of the parking space  20   a  is aligned with the center base line  16  of the elevator car  9   a . The centerlines  14  of the parking spaces  20 , are tangential to a circle  28  having its center at the axis X, where the diameter of the circle  28  is the distance between the centerlines  14  and  16 , of the two elevator shafts  4  and  6 , respectively.  
         [0064]     This arrangement of the two elevator shafts  4  and  6  in which the two center lines  14  and  16  do not lie on radii of the parking level  2  minimizes the area of the central space  26 , which need only occupy an area slightly greater than a single rotating elevator. (Two central elevators whose centerlines lie on a diameter of a circular parking level require a central space at least twice the area of the central space  26 ). A rotary drive (not shown) rotates the rotatable platform  8  around the axis X so as to align the centerline of an available parking space  20  with the center base line of an elevator car  9   a.    
         [0065]     Vehicles  30  are transferred between the elevator cars  9  and the parking spaces  20  by motorized dollies  17  that are attached to the floor of the elevator cars  9  by umbilical electrical or hydraulic cords. The motorized dollies  16  may be, for example, electrically powered through an umbilical point cord tethered to the elevator. The cord winds around a spring-loaded reel so that when the dolly travels out of the elevator, the cord unwinds from the reel, and when the dolly returns to its elevator station, the cord rewinds.  
       Second Embodiment  
       [0066]     Further attention is now directed to  FIG. 3 , illustrating a second embodiment of a parking level  2 , generally indicated by  2   b , that is part of the parking installation  1 . The parking level  2   b  comprises an inner annular parking platform  54 , and a rotatable outer parking platform  56 . The parking platforms  54  and  56  are both coaxial with the axis X of the installation  1 . The inner platform  54  has a sufficiently large inner diameter to surround a central region  59  including four elevator shafts  64   a - 64   d , each servicing all levels of the installation  1 .  
         [0067]     The central region  59  is divided into four quadrants A, B, C and D by a cruciform partition wall  70 .  
         [0068]     In each one of the elevators  64   a - 64   d , is an elevator car  9  upon which an electrically-powered motorized dolly  76  is installed. The motorized dolly  76  is loadable by a vehicle to be parked and functions in the same manner previously described, to transfer a vehicle from an elevator car  9  to a vacant parking space  80  that is in line with the elevator. As in the previous embodiment, the center base lines of the parking spaces  80  do not lie on a radius of the parking platform  2   b . The center base lines  82   a - 82   d  of the elevators  64   a - 64   d , respectively, coincide with the center base lines  86  of a parking space  80 .  
         [0069]     The center base lines  86  of the parking spaces  80 , are tangential to a circle  90  having a common center with the center X of the installation, where the diameter of the circle  90  is the distance between the centerlines of each pair of elevators  64   a  and  64   b ; and  64   c  and  64   d.    
         [0070]     In the embodiment shown in  FIG. 3 , the elevator shafts  64   a - 64   d  in the central bank operate independently. Hence, if four vehicles to be parked enter the installation, they need not await their turn to be parked. Each vehicle may be driven into a different elevator in the elevator bank and transported by that elevator to a level  2   b  in the installation having an available parking space. The outer platform is rotated so that a vacant parking space (e.g. the space  80   a ) is aligned with the elevator. The number of parking spaces is a multiple of four, so that when a parking space is aligned with one elevator, a parking space is aligned with each of the remaining three elevators, so that up to four vehicle transfers from or to the elevators can take place on a single parking level  2   b  simultaneously.  
         [0071]     In the facility illustrated in  FIG. 3  there is a bank of four elevators  64   a - 64   d  in the central region  59 . However, the bank may consist of only two or three elevators depending on the required operating time of the system. Thus with a facility having 10 levels, four elevators operating simultaneously may be necessary to achieve rapid parking. However, if there are only four levels in the facility, a bank of two elevators may be sufficient to provide acceptable fast service.  
         [0072]     The outer stationary platform  56  and the inner rotary platform  54  each has a circular array of parking spaces  80 . The outer stationary platform  56  has a greater number of parking places than the inner rotary platform  54 . The motorized dollies,  57  are powered by a rechargeable battery power pack, and are therefore untethered. The dolly is therefore itinerant, being free to travel throughout the facility to transfer vehicles to and from spaces in the rotary platform  54  and spaces in the stationary platform  56 . The itinerant dollies, when not active, are stationed in vacant spaces in the stationary platform.  
         [0073]     Encircling the stationary platform  56  is a rail  59  with sockets for recharging the power pack of a dolly when a plug at the rear of the pack engages the socket (not shown).  
         [0074]     Since the outer platform  56  is stationary, an elevator  61  may be located in the platform  56  to carry a vehicle to be parked to any level of the facility having a vacant space.  
         [0075]     When a vehicle at the entry/exit  3  level wishes to enter one of the elevators  64   a - 64   d , the vehicle must be correctly oriented with respect to the center line  82   a - 82   d  of the respective elevator, so that the center line of the entering vehicle is aligned with the center line of the elevator so that the vehicle does not veer to one side of the elevator.  
         [0076]     Attention is now directed to  FIG. 4  which illustrates the entry/exit level  3  of a parking installation  1  having the parking levels  2   b . Four turntables  92   a - 92   d  are provided each enclosed within a cylindrical shell  98   a - 98   d , respectively. Each cylindrical shell  98   a  to  98   d  has an entry opening  100   a - 100   d  for a vehicle to be parked, and an exit opening  102   a - 102   d  for a departing vehicle. In operation, a vehicle  110  rides onto the turntable  92   a  through the entry opening  102   a , as shown in  FIG. 4 , and is rotated so that the center line of the vehicle  10  is aligned with the centerline of elevator  64   a . Hence the vehicle  110  can now move into the elevator  64   d  and be loaded on the dolly  76  stationed therein.  
         [0077]     When a vehicle  114  departs the installation  1 , it is brought down by an elevator, say elevator  64   c , and is deposited by its dolly  76  onto the turntable  92   c  The turntable  92   c  then turns to align the vehicle  114  thereon with exit opening  102   c  so as to permit the vehicle to depart the installation.  
       Third Embodiment  
       [0078]      FIG. 5  illustrates another embodiment of a parking level  2 , generally indicated by  2   c . In this embodiment, the installation  1  comprises two elevators  156   a  and  156   b  located within a rotatable central circular region  160  in the interior of an annular stationary platform  162 . The elevators  156   a  and  156   b  share a common wall  164  that lies on a diameter of the parking level  2   c . The elevators  156   a  and  156   b  have parallel center base lines  166   a  and  166   b  respectively that face in opposite directions that are not radially aligned. The platform  162  comprises a plurality of non-radially aligned parking spaces  166 , represented by dashed lines  166 . The difference between the present embodiment and that illustrated in  FIG. 1  resides in that the platform  162  is stationary and is served by the rotary bank of elevators  156   a  and  156   b.    
         [0079]     The bank of elevators rotates, until they are aligned with a parking space. Although the elevators turn together, they travel vertically quite independently which differentiates them from a single central elevator system with two parking places.  
       Fourth Embodiment  
       [0080]      FIG. 6  illustrates another embodiment of the parking level  2 , generally indicated by  2   d . The parking level  2   d  comprises a rotatable annular platform  214  and a stationary platform  224  surrounding the annular platform  214 . Rotatable platform  214  is divided into segments, i.e. is segmented and has a circular array of parking spaces  216  for vehicles  218  and stationary platform  224  has a circular array of parking spaces  226  for vehicles  228 . The parking spaces in both platforms  214  and  224  extend radially with respect to the axis X of the installation  1 . The parking level  2   d  also includes four elevators  210  which are vertically displaceable in the inter-segmentary intervals in the stationary platform  224 . Each elevator  210  carries an electrically powered motorized dolly  211  adapted to accommodate and be loaded by a vehicle to be parked which is transported by the elevator  210  to the parking level  2   d  on whose rotatable platform  214  is a vacant parking space  216 . The platform  214  is then rotated to align the vacant space  216  with the elevator  210 . The dolly  211  then transfers the vehicle  218  from the elevator to the parking space  216  where it is unloaded from the dolly. The unloaded dolly  211  then returns to the elevator  210  so that it can subsequently retrieve the parked vehicle or receive another vehicle to be parked.  
         [0081]     Vehicles can be transferred between the rotatable platform  214  and parking spaces  226  on the outer stationary platform  224  and back by means of an electrically powered, motorized dolly  222  on a turntable  220  whose center is the axis X of the instillation  1 . The rotatable platform  214  rotates so that the vehicle to be transferred is aligned with an available parking space  226  on the stationary platform  224 . At the same time central turntable  220  rotates and aligns dolly  222  with the vehicle and the available parking space  226 . Dolly  222  is then powered to travel under the vehicle, load it, transfer it to the available parking space  226  on the stationary platform  224 , unload it there and then return to the turntable  220 . In reverse, a vehicle  228  parked on the stationary platform  224  can be transferred to the rotatable platform  214 . As the dolly  222  only travels in straight lines, it can be tethered to the center of the turntable  220  by an umbilical electric line.  
       Fifth Embodiment  
       [0082]     Attention is now directed to  FIG. 7  illustrating another embodiment  2   e  of a parking level  2  of the parking installation  1 . The parking platform  2   d  comprises an inner annular rotatable platform  254  and an outer annular stationary platform  256  surrounding the inner platform  254 . Parking spaces are arranged in the outer annular platform with the center base line of each parking space being oriented radially on the platform. Stationary platform  256  includes a bank of three elevators  264   a,b  and c. The elevators  264   a - 264   c  communicate with the parking spaces on the inner rotatable platforms  254  of each of the parking levels to convey vehicles to, and to retrieve vehicles from, the parking level  2   d . Rotating the inner annular platform  254  brings each parking space on the rotatable platform  254  into and out of alignment with an elevator  264  and into and out of alignment with a parking space  282  on the stationary platform  256 .  
         [0083]     An electrically powered, motorized dolly  276  is stationed on each of the elevators that is adapted to accommodate and be loaded by a vehicle that is to be parked. The rotatable inner platform  254  is rotated so as to align a vacant parking space with the elevator  264 . The dolly  276  is then powered to transport the vehicle from the elevator  264  to the vacant parking space on the rotatable platform  254  and to unload the vehicle in the vacant space. The unloaded dolly  276  then returns to its station in the elevator  264  so that it can subsequently retrieve the parked vehicle or receive another vehicle to be parked.  
         [0084]     Vehicles can be transferred between the rotatable platform  254  and the stationary platform  256  by means of electrically-powered motorized dollies  258 , stationed on a turntable  260 , whose center is on the axis X of the installation  1 . The rotatable platform  254  is rotated so that a vehicle in a parking space on the rotatable platform  254  is aligned with an available parking space  282  on the stationary parking platform  258 . At the same time, the central turntable  260  rotates and aligns an electrically powered dolly  258  with the vehicle and the available parking space  282 . One of two dollies  258  is then powered to run under the vehicle, load it, transfer it to the available parking space on stationary platform  256 , unload it and return to turntable  260 . As the dollies travel in straight lines they can be tethered to the center of the turntable  260  by an umbilical electric cord which winds around a spring-loaded reel so that, when the dolly  258  leaves the turntable  260  the cord unwinds and when the dolly returns to the turntable the cord then rewinds. The two dollies  258  are shown in  FIG. 7  as lying on the same diameter of the turntable  260 . In this case the two dollies  258  can only move along radii separated by 180°. Alternatively, each dolly can be supported on a small platform at the extremity of an arm (not shown) that pivots on the axis X (the two arms thus acting like the hands of a clock) so that each dolly can move along radii having any angle between them.  
         [0085]      FIG. 8  illustrates an entry/exit level  3   a  of an embodiment of the parking installation  1  having the parking levels  2   d  shown in  FIG. 7 . The entry/exit level  3   a  includes a rotatable transfer platform  252  and the bank of three elevators  264   a - 264   c . Seven turntables  290  are located outside the rotatable transfer platform  252 . The turntables  290  are enclosed by security walls or screens  292  having three openings that can be closed off by roll down shutters. An entry opening  294  for a drive-in vehicle, an exit opening  296  for a drive-out vehicle and a security opening  298 . Each security wall  292  and corresponding turntable  290  can serve as a drive-in or a drive-out facility, thus at particular peak hours most, or all, of the seven turntables, could serve arriving vehicles and at other peak hours, departing vehicles.  
         [0086]     An important feature of this embodiment is that the center base lines of the three elevators  264  are 22.5° apart and the center base lines of the seven turntables  290  lie on radial lines 45° apart. The rotatable transfer platform  252  in the entry/exit level has 16 transfer spaces on radial lines 22.5° apart. The rotation of the rotatable transfer platform  252  is programmed to stop precisely with the center base line of a transfer space  291  aligned with the center base line of an elevator  264 . Due to the 16-fold radial symmetry of parking level  2   d , the remaining 2 elevators and the 7 turntables will also be aligned with other transfer spaces  291  so that a number of vehicle transfers can take place simultaneously to and from elevators  264   a - 264   c  and to and from turntables  290  while the rotatable transfer platform  252  is temporarily stationary.  
         [0087]     An arriving vehicle rides onto a turntable  290  and is rotated thereby so that the center base line of the vehicle is radially aligned with a transit space  291  on the rotatable transit platform  252 . An electrically powered mechanical dolly  270  on a central turntable  272  transfers the vehicle from the turntable  290  to a transient space  291  on the rotatable transfer platform  252 . The alignment of an available parking space  291  on the rotatable transform platform  252  and a vehicle on a turntable  290  generates a command to the dolly  270  to cross the rotatable transfer platform  274 , which is stationary during the transfer, and enter the security cell  292  through opening  298 . It then loads the vehicle standing on the turntable  290 , transfers it to a transfer space  291  on the rotating transfer platform  252 , unloads it and returns to turntable  272 . The reverse procedure is performed when a vehicle is to be moved from the rotatable transfer platform  252  to a turntable  290 . The motorized dollies  270  may be powered through umbilical cords tethered to the turntable  272 . The four motorized dollies on the center turntable  272  are shown at fixed right angles to each other, so that when the turntable  272  is aligned with a turntable  290 , the other three dollies will be aligned with three other turntables  290 . As described above, the four dollies can also be supported by swinging arms (not shown) that pivot around the central axis, much like the hands of a clock.  
         [0088]     Vehicles are transferred from the rotatable transfer platform  252  to an elevator  264  by an electrically-powered, motorized tethered dolly  276  stationed in the elevator; which moves under the vehicle on the rotatable transfer platform; loads the vehicle and transfers it to the elevator which then rises or descends to a parking level. The reverse procedure occurs when a departing vehicle is to be moved an elevator  264  to the rotatable transfer platform  252 , and in a further transfer, onto a turntable  290  during departure.  
       Sixth Embodiment  
       [0089]      FIG. 9  illustrates a parking level  2  in accordance with another embodiment generally indicated by  2   e . This embodiment includes an inner stationary platform  325 , an outer stationary platform  330 , and a rotatable platform  315 . It also includes six equally spaced elevators  310  in the outer stationary platform  330 . A dolly  305  parked on a central turntable  320  and tethered to a central point of said turntable, is enabled to transfer a vehicle from the rotatable parking platform  315  to a parking space on the inner stationary parking platform  325  and also to perform the reverse procedure. The large number of parking spaces on every level necessitates a large number of elevators (6). Spacing of vehicles on the parking level  2   e  is along radial lines at 12° spacing from each other. Elevators are on radial lines spaced 60° apart. Every parking space on the inner stationary platform  325  is radially aligned with every second parking space on the rotatable parking platform  315 . Thus when one of the 30 parking spaces on the rotatable parking platform  315  is aligned with an elevator, another five parking spaces will simultaneously be aligned with the remaining 5 elevators and 15 of the parking spaces will be simultaneously aligned with 15 parking spaces on the inner circular parking platform  325 . At peak arrival and departure times, these features increase the number of vehicles that can be handled simultaneously.  
         [0090]      FIG. 10  illustrates an entry/exit level  3   b  of an embodiment of the parking installation  1  having parking levels  2   d . The entry/exit level  3   b  includes turntables  290  enclosed by security mesh with roll down gates  292  for drive-in entry, drive-out exit and transfers between turntable and elevator, as in the embodiment shown in  FIG. 8 . In comparison to that embodiment, a rotatable transfer platform  252  has a greater diameter and there are more turntables. Each of six dollies  400  is tethered to an individual transfer platform  410  which travels on arcuate tracks  420  in shallow recesses  425  in the central area. The upper surface of each platform  410  is level with the overall floor level, the level of the platform  252  and the level of the turntables  290 . Each platform  410  is motorized and travels between two radii connecting the center of two adjacent turntables to the axis X of the instillation  1 . The platform  410  is positioned at one limit of its travel, at which position it&#39;s center base line and the center base line of the dolly  400  is carrying is aligned with a vehicle on a turntable. The dolly leaves its platform, travels over a vacant parking space on the rotatable transfer platform  430 , stops under the vehicle; lifts it and carries it to the vacant parking space, unloads it and returns to the small platform. The process is reversed when a vehicle is to be moved from the rotatable parking platform to the turntable.  
       Seventh Embodiment  
       [0091]      FIG. 11  illustrates an embodiment of the elevator car  9  that may be used with any of the embodiments of the invention. The embodiment of  FIG. 11  is a double-decker elevator car that can accommodate two vehicles simultaneously, one on top of the other, where the difference in the levels of the two vehicles corresponds to the difference in the levels of two adjacent parking levels (or the exit/entry level and a parking level) in the installation  1 . The elevator is built like a freight elevator having a cabman  120  suspended on steel cables  121  stiffened by a regular double beam structure  122 .  
         [0092]     The elevator  120  includes an upper floor  125  supported by two or more vertically-extending columns  126  whose height is fixed to align the upper floor  125  and the lower floor  129  with the surfaces of two adjacent parking levels  2  and  2 ′ from which or to which the two vehicles are to be transferred. Floor  125  of the elevator has a dolly  127   a  therein for transferring the vehicle on that floor to the parking level  2 , and lower floor  129  has a dolly  127   b  therein for transferring the vehicle on that floor to the adjacent parking level  2 ′.  
         [0093]     Both floors  125  and  129  preferably include chocks  130  at both ends of the dollies  127  to prevent horizontal movement of the dollies and vehicle until the floors  125  and  129  are aligned with the parking levels  2  and  2 ′, respectively. The elevator may be provided with sensors and controls to assure that the chocks  130  can only be withdrawn into the elevator floor when the elevator floor is properly aligned with the a parking level  2  or an entry/exit level  3 . No elevator doors are then required.  
         [0094]     While in the specific embodiments described above the use of tethered and untethered motorized vehicles has been mentioned, it is clear that an AGV type device can be used throughout.

Summary:
A multi-level, automated vehicle parking structure comprising a plurality of horizontal, planar platform assemblies respectively located on a plurality of structure levels through which a central air shaft extends vertically. Each assembly comprises a rotary platform surrounding the shaft that is rotatable about a vertical axis of rotation extending through the shaft. In one embodiment, at least two oppositely directed vehicle elevators vertically and separately displaceable in the shaft have respective, substantially parallel, base centre lines that are off-radial with respect to the axis of rotation. Each rotary platform has a plurality of parking spaces arranged in circular array with respect to the axis of rotation and having respective base centre lines off-radially inclined in the same sense with respect to the axis of rotation Each rotatable platform is rotatably displaceable so as to bring any selected pair of opposite parking spaces into respective communication with the elevators with the central base lines of the elevators being co-directional with the central base lines of the selected parking spaces. The structure further comprises at least one vehicle entry and exit level for selective communication with the elevators for transfer thereto and therefrom of vehicles to be parked and to be retrieved. Motorised dollies transport vehicles between the elevators and the parking spaces on the stationary platform.