Abstract:
A vehicle parking structure particularly well adapted for providing a parking capacity of up to about 20 vehicles has a structure framework with an entrance/exit level and a plurality of parking level floors, each of the floors having a pair of parking bays located on opposite sides of an elevator shaft. Vehicles to be parked are driven onto a vehicle tray, which is raised and lowered by means of an elevator in the elevator shaft. The elevator includes a shifter on which the tray is supported which allows the tray to be cantilevered outwardly from the elevator at a parking level. With the tray so cantilevered outwardly, the tray is incrementally lowered to rest on a pair of tray supports in the desired parking bay. The shifter is then retracted and the elevator can be raised or lowered to another level as required. To retrieve a vehicle, the elevator and shifter is positioned incrementally below the identified tray, and the shifter is extended into the bay. Raising the elevator incrementally lifts the tray from the parking bay such that it is supported by the shifter, which can then be retracted with the tray. The elevator is then raised or lowered as required. Operation of the elevator drive and the shifter may preferably be carried out under the control of a microprocessor control system.

Description:
BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 3,497,087 to one of the present inventors discloses an automatic vehicle parting system intended to provide a tiered parking structure the dense parking of parked vehicles. Such a construction contemplated significant economies in both site utilization and operation, providing parking for a plurality of vehicles upon a relatively limited land space area. In that inventor&#39;s subsequent U.S. Pat. No. 5,980,185, an improved automated parking garage structure is disclosed utilizing a rectilinear, rather than cylindrical structure. 
     The foregoing and other parking systems are of significant utility, as they each allow significant utilization of limited land space, allowing vehicles to be parked and stacked in a vertical-extending array. In general, such constructions are more efficient than conventional non-mechanized parking garage structures, where access is obtained through ramps sloping through the structure, the vehicles being driven, rather than carried, to a parking location. 
     Yet even these automated structures require a relatively large plot of land and are of a complex and expensive construction. While the number of vehicles which may be parked therein is large, the economies of scale require a large investment. Often there is a need for a parking structure of more limited capabilities. The land available may be impractical or insufficient for the construction of a parking structure having a large number of parking spaces on a given level, requiring expensive and complicated shuttle means to both raise the vehicle to the level and to direct the vehicle horizontally into a chosen one of a relatively large plurality of stalls. Alternatively, sufficient funds may be unavailable for a large structure, or the parking requirements for the location may be more modest. 
     It is accordingly a purpose of the present invention to provide an automated vehicle parking/storage facility capable of being constructed and operated on relatively small land areas. 
     Yet a further purpose of the present invention is to provide such a storage structure which is of economical construction and efficient operation. 
     Another purpose of the present invention is to provide a parking structure of the aforementioned general format which does not require driver assistance for vehicle parking or retrieval. 
     SUMMARY OF THE INVENTION 
     In accordance with the foregoing and other objects and purposes, a vehicle parking structure in accordance with the present invention comprises a structure having a central vertical elevator shaft having elevator means for raising an unoccupied vehicle to be parked or stored from an entrance level location to a chosen parking stage level or story and depositing the vehicle in an empty stall at the level, as well as for retrieving a parked vehicle from a stall and returning it to the entrance level location for departure from the structure. Each parking story comprises parking space for two vehicles, one space on each of opposite sides of the elevator shaft. 
     A vehicle to be parked is driven onto a tray on the elevator at the entrance level. The tray sits upon a shifter means that includes an extension mechanism which allows the tray to be extended and held outwardly of the elevator shaft in one of two opposite directions when the elevator is raised to the level of the intended vacant stall, to position the tray within the intended stall and lower the tray and vehicle onto supports in the stall. The extension mechanism then retracts and returns to a central, neutral position within the elevator shaft. The elevator can then be directed either to the entrance level to accommodate a new vehicle to be stored or to a parking level to retrieve a parked vehicle. 
     A parked vehicle is retrieved by positioning the elevator such that shifter is slightly below the level of the tray on which the vehicle is located, extending the extension mechanism to align with the vehicle, raising the elevator to lift the tray and vehicle from the supports and retracting the extension mechanism to the neutral position within the shaft The parked vehicle is then lowered to the entrance level stage for drive off. 
     An interlock system is provided to maintain a tray on the supports of a parking stall. The interlock is disengaged when the shifter deposits or removes a tray from the supports. Such as interlock is of significant value, particularly in high wind areas, since unoccupied trays are stored in the stalls and can be subject to large wind-induced forces. The shifting apparatus is of unique and simplified construction, allowing for efficient operation. A garage utilizing the elevator and shifter may be adapted to varying heights and parking levels, in accordance with the numbers of vehicles to be stored. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A fuller understanding of the present invention will become apparent upon consideration of the following detailed description of a preferred, but nonetheless illustrative embodiment thereof, when reviewed in connection with the annexed drawings, wherein: 
     FIG. 1 is a front elevation view of an illustrative embodiment of the parking structure of the present invention; 
     FIG. 2 is a section view taken along line  2 — 2  of FIG. 1 depicting the elevator pit portion of the structure; 
     FIG. 3 is a section view taken along line  3 — 3  of FIG. 1 depicting the invention at ground level; 
     FIG. 4 is a section view taken along line  4 — 4  of FIG. 1 depicting the construction of the parking structure at a parking level and illustrating shift operation at a parking level; 
     FIG. 5 is a perspective view of a portion of the elevator at a parking level showing the shifter in an extended position; 
     FIG. 6 is a detail partial plan view depicting the drive for the shifter; 
     FIG. 7 is a partial section view taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a partial section view taken along line  8 — 8  of FIG. 7; 
     FIG. 9A is a top plan view of a portion of a stall showing a tray with a vehicle thereon being supported in the stall, the shifter being in alignment with the stall and the tray lock in the unlocked position; 
     FIG. 9B is a top plan view of the portion of the stall showing the a tray with a vehicle in the stall and the tray lock in the locked position; 
     FIG. 10 is a top plan view of the portion of the stall showing a tray and vehicle on the shifter having been lifted from the stall, the shifter being returned to the central position and the lock in the locked position; 
     FIG. 11 is a section view taken along line  11 — 11  of FIG. 9A; 
     FIG. 12 is a section view taken along line  12 — 12  of FIG. 11; and 
     FIG. 13 is a section view taken along line  13 — 13  of FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to FIG. 1, parking structure  10  comprises a plurality of floors or levels  12 , each adapted to store two vehicles  14  in a pair of parking stalls  16 , each of which is on an opposite side of central elevator shaft  18 . The parking structure  10  may be economically constructed in a lattice-type construction, and may be of variable height, subject to zoning height restrictions, based upon the number of vehicles sought to be accommodated thereby. It is contemplated that upwards of ten parking floors or levels  12  can be accommodated in a structure of reasonable cost, thus allowing a maximum of 20 vehicles to be stored. 
     A series of vertically extending I-beams  20  extend vertically for the height of the structure, and are interconnected by horizontal beams  22  to establish the entrance and parking levels of the structure. As further seen in FIG. 2, four interiorly-located I-beams  20  define corners of the elevator shaft  18 , in which elevator  24  is installed for vertical travel between the entrance and parking levels  12 . The elevator  24  is dimensioned to support tray  26 , depicted in FIG. 3, the tray having a length and width sufficient to receive a vehicle  14  thereon, the vehicle being driven onto the tray from an end thereof when the elevator is positioned at the ground or entrance level. To allow the tray to be in general vertical alignment with the ground level of the structure, the elevator shaft may include a below-ground pit area, the floor of which serves as a portion of the base for the structure. As may be seen in FIG. 3, the tray  26  may include a pair of spaced guides  28  for the vehicle&#39;s tires to assist the driver in properly aligning and maintaining a vehicle on the tray as it is driven on and off the tray at the entrance level. A pair of stub beams  30  are mounted to each end of the tray at its the bottom surface to serve as supports for the tray when the tray is transferred to a parking stall, as will be discussed infra. The beams  30  may preferably be ID formed of box-beam segments welded to the aluminum tray, extending approximately  91  beyond the ends of the tray. 
     As also depicted in FIG. 3, the ground or entry level for the structure may include a peripheral wall  32  about the elevator shaft to protect users and operating personnel from inadvertently approaching the elevator shaft. Doors  34  allow controlled access to the elevator and the vehicle thereon. 
     With reference to FIG. 2, the elevator frame may be formed of a pair of spaced longitudinal beams  48  between which is located a support structure  50  for a drive motor  36 . A tray shifter assembly  52  is mounted transversely to the frame at the front and rear end of the elevator. The shifters support the vehicle tray  26 , allowing the tray to be directed to either side of the elevator as required. The construction details of the shifters are illustrated in FIGS. 7 and 8. Each shifter is preferably independently powered by its own electric motor, the motors operating in synchronism, such that both shifters work in unison. 
     Raising and lowering of the elevator is performed by the electric motor  36  mounted to the elevator frame. As further seen in FIG. 5, a pair of opposed transmission shafts  38  couple the motor shaft to gear boxes  40  at the front and rear ends of the elevator. Drive shafts  42  are provided with gears  44  at the ends thereof which mesh with vertical gear racks  46  mounted to the l-beams which form the perimeter of the elevator shaft way. An appropriate cable (not shown) provides electric power to the motor from a control box, preferably located at ground level. Appropriate sensors may be mounted to the elevator and positioned along the length of the elevator shaft to provide position information to allow the elevator to be positioned as appropriate with respect to the parking levels. 
     Referring further to the view of FIG. 5 in conjunction with FIGS. 6 and 7, each of the shifters  52  comprises a pair of right-angle members  54  which are bolted or otherwise affixed transversely to the main longitudinal elevator beams  48 . A series of opposed rollers  56  are mounted along the length of the right-angle members and support lower rolling beam assembly  58 . The lower rolling beam assembly  58  comprises a pair of upper and lower plates  60  separated and supported by box beams  62 . The height of the box beams  62  is chosen such that the plates  60  can straddle and capture the rollers  56 , the upper plate  60  riding on the rollers. The flanged construction of the rollers, along with the positioning of the box beams just inward of the rollers, maintains the positioning of the lower rolling beam assembly thereon. 
     Mounted to the upper plate  60  is a pair of upper rolling beam right angle supports  64 . The upper supports  64  are mounted to the lower rolling beam assembly  58  by bolts  66 , which also secure the upper and lower plates  60  and the box beams  62  of the lower rolling beam assembly together. The upper rolling beam supports  64  in turn have upper rollers  68  mounted thereto upon which upper rolling beam assembly  70  travels. The upper rolling beam assembly  70  is constructed in a manner analogous to that of the lower rolling beam assembly, and comprises a pair of spaced plates  72  separated by and mounted to box beams  74 . The upper and lower rolling beam assemblies  70 ,  58  are thus arranged to extend in a cantilever fashion from the elevator and elevator beams  48 . Each of the rolling beams may be about 7 feet long, consistent with the width of the tray to be supported thereon which is of a similar width. The cantilever construction allows a tray to be extended outwardly to either side of the elevator so that it is fully beyond the width of the elevator shaft, as shown in FIG. 4, whereby the shifter-supported tray can be aligned with a parking stall and placed therein. The shifter can then be retracted and the elevator repositioned as needed for another vehicle. 
     The extension/retraction drive for both the lower and upper rolling beam assemblies  58 ,  70  is provided by motor assembly  76 , which may include electric motor/gear box  78 . Motor bracket  82 , which supports the motor/gear box, is mounted to one of the upper rolling beam assembly supports  64  by a set of posts  84 . Thus, the motor drive unit travels with lower rolling beam assembly  58 . 
     The output shaft of the motor/gear box  78  bears pinion gear  86  which engages a pair of opposed gear racks  88  and  90 . The first gear rack  88  is mounted to right angle gear rack support  92 , which in turn is bolted one of the L members  54 . As the L member  54  is affixed to the elevator frame, motor operation drives the motor and thus rolling beam assembly  58  in extension to (or retraction from) one side or the other of the elevator with respect to the elevator frame. Second gear rack  90  is mounted to upper rack support  94 , which in turn is bolted to the upper rolling beam assembly  70 . Bolts  96  may affix the gear rack support  94  thereto, and at the same time, join the upper and lower plates  72  with the box beams  74 . It may be appreciated that, with the motor energized, at the same time as the lower rolling beam assembly extends out along the first fixed rollers  56 , the upper rolling beam assembly  70  extends relative to the lower rolling beam assembly. Upon reversal of the motor corresponding simultaneous retraction of both the upper and lower rolling beam assemblies is performed. The desired cantilever effect is thus produced. 
     The vehicle-receiving tray  26  is supported upon the shifters by the upper rack supports  94 , which may be in the form of right angle beams. The substantial mass of the tray in general is sufficient to maintain the tray in position on the shifters, both as it is raised and lowered by the elevator, as it is shifted laterally at a parking level, and when it is deposited at or lifted from a desired parking stall. To further insure stability when the tray is in a stall, however, an interlock system may be provided. When a tray is in the received position in a stall of the structure, the stub beams  30  of the tray are supported by and rest upon pairs of corresponding forward and rear tray support brackets  98 , mounted to the vertical I beam columns  20  that form the stall corners. To lock the stub beams and tray to the support brackets, the locking system depicted in FIGS. 9A-13 may be employed. 
     A pair of the stall support brackets  98 , either at the front or rear of the stall, is provided with a locking assembly  100  that is engaged by the shifter as the shifter is directed laterally into alignment with the stall. The locking assembly  100  comprises a pair of rotating finger or key lock elements  102  that rotate between two opposed perpendicular orientations, as depicted in FIGS. 9A and 9B. The keys are journaled in the horizontal portion of the support bracket  98  and project upwardly therefrom. The keys are dimensioned to engage with corresponding elongated apertures  106  located at the bottom surfaces of the box beam stubs  30  of the tray  26  when in a first orientation, and be perpendicular to the apertures in a second orientation. With the keys aligned with the apertures the tray can be placed on or raised from the support brackets. With the tray in position on the support brackets  98  and the keys perpendicular to the major length of the apertures, the stubs  30 , and thus the tray, is locked to and retained on the brackets. 
     Rotation of the keys in coordination with motion of the shifter is provided for as follows. Each of keys  102  is mounted on a shaft  104 . An elongated spacer bushing  108  surrounds the shaft below the bracket  98 , and a push arm  110  is affixed to the shaft below the spacer. The push arms  110  are in turn pivotally connected to main tie rod  112 . Reciprocating motion of the tie rod  112  thus pivots the keys. The inward facing end of the tie rod  112  is provided with a contact plate  114 . The contact plate  114  is aligned with actuator  116  mounted to the shifter. A bias spring  118  is connected between the main be rod  112  and a tray bracket  98 , whereby the locking assembly  100  is normally biased to the right as shown in FIG. 10, the keys  102  being perpendicular to the slots  106  in the box beam stubs  30 . With a tray in position on the support brackets, the lock is thus engaged. 
     FIG. 9B depicts a tray  26  and a vehicle  14  positioned on the tray brackets  98  and locked in a stall. When it is desired to retrieve the tray and vehicle, the vacant elevator is raised to the stall level and the shifter energized to move transversely into the stall slightly below the tray. As the shifter becomes generally aligned with the tray, the actuator  116  engages the plate  114 , driving the tie rod  112  to the left until the position depicted in FIG. 9A is reached. The shifter is now fully aligned with the tray, and the keys  102  have been pivoted  90  degrees counterclockwise such that they are in alignment with the apertures  106  in the box beam stubs. The tray is thus unlocked, and upward travel of the shifter allows the tray to be engaged thereby and lifted from the support brackets  98 . The shifter can then be retracted, bringing the tray into the elevator shaft, the pushrod assembly being returned to its rest (locked) position by bias spring  118  as the actuator  116  backs away from contact with the plate  114 . 
     Preferably the actuator  116  is centrally located on the shifter, and is appropriately dimensioned with a pair of opposed contact ends thereon to allow contact to be made with the pushrod assemblies associated with the parking stalls on both sides of the elevator as the shifter is moved thereto. When a vehicle is to be deposited in a stall, the elevator, with the vehicle-occupied tray on the shifters, is raised to a position whereby the tray on the shifter is slightly above the support brackets  98  of the intended receiving stall. The shifter is extended, and the actuator  116  contacts the plate  114  as the shifter and tray approaches final horizontal alignment within the stall. The contact and engagement with the plate rotates the keys  102  to their unlocked orientation as the tray is simultaneously brought into final horizontal alignment in the stall. The elevator is then incrementally lowered, lowering the tray onto the support brackets  98 , the elevator being further incrementally lowered to separate the shifter from the stall-supported tray with the shifter separated from the tray, retraction of the shifter into the elevator shaft disengages the pushrod assembly, allowing it to return to the rest position, locking the tray in position on the tray supports. It is to be noted that the contact plate  114  is of a sufficient surface area to allow continued contact with the actuator  116  during the incremental raising and lowering of the shifter during the deposit and removal of the tray from the support brackets. The actuator  116  may be provided with low friction tips, such as of Teflon or the like, to minimize frictional effects as the shifter is raised and lowered while the actuator is in contact with the plate. 
     Coordinated operation of the main elevator motor  36  and the shifter drive motors  78  is preferably performed by a microprocessor control system  120 , which may also monitor the location of occupied and unoccupied stalls and control the automated storage and retrieval of vehicles in the stalls. The control system may be located in operator&#39;s booth  122  and coupled to the motors, sensors and other operating elements by cabling as known in the art. The control system can provide for either attended or unattended operation. In typical operation each stall is provided with a tray which may be individually identified, such as by a bar coding which can be read by an appropriate sensor associated with the elevator/shifter. In an initial position, one of the trays is removed from its stall by the elevator/shifter and the elevator is positioned at the ground level to await receipt of a vehicle to be parked. The vehicle is driven onto the tray and the occupants exit. The occupants leave the elevator perimeter and the shaft way doors are closed. The control system is actuated, the tray and vehicle being raised to the level of the stall from which the tray was obtained, and the tray redeposited therein. As previously indicated, this is accomplished by the elevator initially being positioned by the control system such that the tray on the shifter is slightly above the level of the stall tray supports and the lock keys are cleared by the tray as the shifter is extended. As the shifter is extended the lock system is engaged, the lock keys being pivoted to the unlocked position. With the shifter emended such that the tray is properly aligned with the support brackets, the elevator is lowered to place the tray on the supports and separate the tray from the shifter. The shifter is then retracted, the lock keys returning to the neutral position, locking the tray on the supports. 
     With the shifter fully retracted the elevator can then be directed to a level to retrieve another tray for delivery to the ground level. The tray may either be occupied, if a command is entered to retrieve a parked vehicle, or may be unoccupied if there is a vehicle waiting to be parked. Once an occupied tray is retrieved and lowered to the ground level, the shaft way doors are opened, allowing the vehicle&#39;s occupants to enter the vehicle and drive the vehicle away. The elevator can then remain at the ground level, awaiting the entry of another vehicle which is placed in the empty stall from which the tray was retrieved, or can return the tray to its stall if another occupied tray is to be retrieved. 
     By incorporating a microprocessor control system, it is possible to develop and implement transfer routines that can improve the efficiency of system operation. If a stall is not provided with a tray, for example, it is possible to transfer occupied trays between stall locations. This can be of value in minimizing retrieval time, especially if the approximate return time for a vehicle is known. Vehicles having an earlier return time may be placed at the lower levels of the structure to minimize elevator travel time to expedite the retrieval process. Shifting of the vehicles between stalls can be performed during slack periods, and can be performed automatically by the control system according to appropriately designed algorithms.