Abstract:
A mobile storage system includes movable storage units that can be positioned to selectively form an aisle between adjacent storage units. The storage units define a maximum aisle space that forms a single aisle between an adjacent pair of storage units, or a number of aisles between several adjacent pairs of storage units by distributing the maximum aisle space between at least two aisles. A control arrangement controls the position of the storage units, in response to user commands, so as to form the aisles. The control arrangement may be configured such that, when a pair of aisles are present between two pairs of storage units, one of the aisles is closed based on certain criteria when a command to open a different aisle is initiated. The criteria may be user defined, or may be a characteristic such as the frequency of use of the aisles such that the more frequently used aisle remains open and the less frequently used aisle is closed.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of provisional patent application Ser. No. 60/761,936 filed Jan. 25, 2006. 
    
    
     BACKGROUND AND SUMMARY 
     This invention relates to a storage system, and more particularly a storage system of the type in which a series of movable storage units are selectively moved together and apart to form an aisle between adjacent storage units. 
     A mobile storage system typically consists of a number of storage units that are selectively movable relative to each other to form an aisle between an adjacent pair of storage units. The storage units are typically mounted to a pair of spaced apart rails, and each storage unit includes a carriage having wheels that are movable on the rails. Each storage unit includes a drive motor that is responsive to commands input from an operator, so as to provide movement of the storage unit on the rails. In the prior art, the number and spacing of the storage units are selected relative to the length of the rail such that a single aisle having a predetermined width can be created between any selected adjacent pair of storage units. 
     It is an object of the present invention to provide a mobile storage system that is configured and arranged to enable the storage units to be positioned such that a pair of aisles can be formed between two spaced apart sets of adjacent mobile storage units, in order to provide access to two different sets of storage units at any one time. It is a further object of the invention to provide a mobile storage system that enables the storage units to be positioned so as to provide a single, relatively wide aisle between an adjacent pair of storage units, so as to enable a relatively wide object to be positioned between the storage units, such as a wheelchair, a filing cart, etc. Yet another object of the invention is to provide such a storage system which is operable in response to certain criteria to maintain a certain aisle or aisles open when an operator wishes to create an aisle between a different pair of storage units. 
     In accordance with the present invention, a mobile storage system includes a number of mobile storage units that are movable toward and away from each other to selectively form an aisle between adjacent storage units. The storage units are arranged to define a maximum aisle space within the mobile storage system, which is capable of forming a single aisle between an adjacent pair of storage units or a number of aisles between several adjacent pairs of storage units. A control arrangement is operable to control the position of the storage units relative to each other, and is operable to position the storage units in response to user commands so as to form one or more aisles between the storage units. The control arrangement is operable to form either a single aisle between an adjacent pair of storage units using the maximum aisle space, or a number of aisles between a several adjacent pairs of storage units system by distributing the maximum aisle space between at least two aisles located between at least two adjacent pairs of mobile storage units. 
     The control arrangement may include a surveillance unit configured to monitor the presence of an object within the aisles, and is responsive to the surveillance unit to prevent movement of the storage units between which an aisle is located when an object is present in the aisle. In addition, each storage unit includes an actuator that is selectively operated by a user to cause relative movement between the storage unit and an adjacent storage unit to form an aisle therebetween. The actuators and the control arrangement may be configured such that, when each actuator is initially actuated, an aisle having a width less than the maximum aisle space is formed between the storage unit and an adjacent storage unit. When each actuator is subsequently actuated after the initial actuation, an aisle having a width equal to the maximum aisle space is formed between the storage unit and an adjacent storage unit. 
     The control arrangement may be configured such that, when creating an aisle between an adjacent pair of storage units when a pair of aisles are present between two other adjacent pairs of storage units, one of the aisles between the two other adjacent pairs of storage units is closed based on one or more predetermined criteria. The predetermined criteria may be a user defined designation, or may be a characteristic such as the frequency of use of the aisles such that the more frequently used aisle remains open and the less frequently used aisle is closed. 
     The invention also contemplates a method of operating a mobile storage system including a number of movable storage units, substantially in accordance with the foregoing summary. 
     Various other features, objects and advantages of the invention will be made apparent from the following detailed description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode presently contemplated of carrying out the invention. In the drawings: 
         FIG. 1  is an isometric view of a mobile storage system incorporating the multiple simultaneous aisle access control in accordance with the present invention; 
         FIGS. 2-11  are side elevation views of the mobile storage system of  FIG. 1 , showing the storage units incorporated in the mobile storage system and the various movements of the storage units to form one or more aisles between adjacent storage units; and 
         FIG. 12  is a schematic view of components incorporated in a controller forming a part of the mobile storage system of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1-11  illustrate a mobile storage system  20  which includes a series of upright storage units  22   a - g , each of which generally includes a shelf or cabinet  24  and a base assembly including an individually mobile carriage to which the shelf or cabinet  24  is mounted. Each cabinet  24  is mounted to its respective mobile carriage for lateral movement within the mobile storage system  20 . Each storage unit  22   a - g  is movable along, for example, a set of rails  14  by a prime mover, such as an electric motor connected to a drive wheel which runs along at least one of the rails. In a manner as is known, a scissors-type pantograph (not shown) may extend between adjacent storage units  22   a - g  for routing power and communication cables to the components of mobile storage system  20 . The general construction and operation of this type of mobile storage system is known in the art, and is available from Spacesaver Corporation of Fort Atkinson, Wis. 
     Each of the storage units  22   a - g  is arranged to move alternately and selectively to the left and right as depicted to establish at least one access aisle between the storage units  22   a - g  at the command of an operator. As shown in  FIGS. 1-11 , the storage units  22   a - 22   g  are arranged to move rectilinearly relative to each other to establish at least one access aisle between any two of the storage units  22   a - 22   g . In one embodiment, end storage units  22   a  and  22   g  may be stationary. It should be understood at the outset that the improved mobile storage system  20  described herein is adapted for controlling a system that has fewer or more storage units than are depicted in  FIGS. 1-11 , and that the end storage units  22   a  and  22   g  may or may not be movable. 
     In the illustrated embodiment, storage units  22   b - 22   f  are generally identical in construction and operation. A typical storage unit  22   c  has an operator input controller, represented by the rectangle marked  26 , which may be mounted on an end of the storage unit  26  or in any other satisfactory location. An open aisle push button switch  28  is included in the controller  26 . Controller  26  may also include other features such as an emergency stop button (not shown), as well as indicia or lights indicating operation status. The open aisle push button switch  28  is actuated by an operator to initiate the aisle opening procedures discussed in greater detail below. 
     A variety of known safety mechanisms can be utilized with the mobile storage system. For example, the safety mechanism may be in the form of a sweep or safety switch bar for notifying the control system associated with the drive arrangement of each storage unit to stop motion of the storage unit if an obstacle or impediment to movement is encountered. Examples of safety mechanisms are illustrated in U.S. Pat. Nos. 4,743,078 and 4,733,923, the disclosures of which are hereby incorporated by reference. Alternatively, a photoelectric sweep disclosed in, for example, U.S. Pat. No. 5,121,975, the disclosure of which is hereby incorporated by reference, could be utilized. Another alternative includes a system as shown in U.S. Pat. No. 5,427,444, also incorporated by reference, which illustrates a directional detector that detects entry of an obstacle into the aisle and prevents movement until the obstacle is detected to have left the aisle. Still another alternative includes a system as shown in U.S. Pat. No. 6,707,028, also incorporated by reference, which illustrates an object detection system for use in detecting the presence of an object within a space that includes a pair of pivotable light emitter/receiver units located outwardly of each side of the space and a series of reflectors located outwardly of each side of the space. 
       FIGS. 2-11  illustrate a series of alternative positions of the storage units  22   a - 22   g  of mobile storage system  20  in accordance with the present invention. As noted above, at each end of mobile storage system  20 , a stationary storage unit may be provided or the endmost movable storage unit may be located adjacent a wall or other stationary structure. When at least one of the mobile storage units  22   a - 22   g  is moved apart from an adjacent mobile storage unit  22   a - 22   g  or wall, an aisle or space is formed therebetween. The aisle provides access to the contents of the mobile storage units  22   a - 22   g  on either side of the aisle. Before an aisle is formed, an object detection system or surveillance unit  60  of logic system  58  ( FIG. 12 ) according to the invention is employed so as to ensure there are no obstructions in the path of movement of mobile storage units  22   a - 22   g  before commencing operation of the motors associated with the storage units  22   a - 22   g  so as to move the mobile storage units  22   a - 22   g  as necessary to close an aisle. In addition, as described in greater detail below, when an aisle is to be formed, logic system  58  utilizes a distance sensing unit  62  and an intelligence unit  64  to monitor the distance between storage units  22   a - 22   g  and uses the information to determine how wide to open a single aisle, which aisles to open if individuals or objects are present in an existing aisle, as well as which aisles to open based on a determination of which aisles are most frequently used. 
     In accordance with the present invention, the controller of mobile storage system  20  is programmed to maintain a maximum aisle space (MAS). In one embodiment, the MAS is sixty inches, however, a variety of MAS widths may be maintained depending on the requirements of the system. The MAS may be divided in a variety of ways within the mobile storage system  20 . For example, as illustrated in  FIGS. 2 and 3 , the MAS can be divided between two discrete aisles  36  and  38 . Alternatively, as illustrated in  FIG. 4 , the MAS can be utilized to form a single widened aisle  34 , which may, e.g., be used to provide wheelchair access or to accommodate equipment used to load or unload the storage units. In the illustrated embodiment, actuation of an open aisle button  28  on a mobile storage unit  22   a - 22   g  causes one or a number of adjacent individual storage units to move to form an aisle. Once an aisle is already open, actuation of open aisle button  28  a second time causes the aisle to open further and create an aisle with a width equal to the MAS. 
     A variety of representative operational sequences will be described in reference to  FIGS. 1-11  illustrating the advantages of the mobile storage system  20 .  FIG. 2  illustrates mobile storage system  20  with aisles  36  and  38  open. As noted above, when two aisles are open, the MAS is divided equally among the two aisles. In the illustrated embodiment, aisles  36  and  38  may each have a width of about thirty inches. When an operator would like to open an aisle between mobile storage units  22   c  and  22   d , the operator presses an open aisle push button switch  28  in the controller  26  located on mobile storage unit  22   c . Once actuated, the logic system  58  of the mobile storage system  20  must make a “decision” based on a variety of factors. In the illustrated, as shown in  FIG. 12 , a safety or surveillance unit  60  of the mobile storage system  20  will perform a check and detect an empty aisle  38  as well as the presence or absence of an object, such as a person P, in open aisle  36 . If an object is present in open aisle  36 , the controller of mobile storage system  20  will initiate a movement such that aisle  36  will remain open and aisle  38  will be closed to form aisle  34 , as illustrated in  FIG. 3 . Aisle  38  is closed and aisle  34  is opened by the movement of mobile storage unit  22   c  to a position adjacent mobile storage unit  22   b . The distance sensing unit  62  will maintain a distance of thirty inches for aisles  34  and  36 . 
     When aisle  36  is empty, it can be closed in a subsequent action, such as shown in  FIG. 4 . If, for example, an operator would like to further widen aisle  34  to create wheelchair access, the operator presses the same open aisle push button switch  28  in the controller  26  located on mobile storage unit  22   c . Once actuated, the logic system  58  of the mobile storage system  20  must again make a “decision.” In the illustrated embodiment, the safety or surveillance unit  60  of the mobile storage system  20  will detect that aisle  36  is empty. Therefore, the controller of mobile storage system  20  will initiate a movement causing mobile storage units  22   d  and  22   e  to move toward mobile storage unit  22   f  thereby closing aisle  36  and widening aisle  34  to a width equal to the MAS. The distance sensing unit  62  will maintain a width of sixty inches for aisle  34 . 
     Turning now to  FIG. 5 , an obstacle, such as a person shown at P is present in the widened aisle  34 . Therefore, if an operator desires to open another aisle, for example, between  22   f  and  22   g , the controller of mobile storage system  20  will not complete this function. The distance sensing unit  62  will indicate that the MAS has been fully utilized and the safety or surveillance unit  60  will indicate the presence of the person  30  within the open aisle  34 . A signal will be sent preventing any movement of the mobile storage units  22   c ,  22   d  adjacent the occupied aisle  34 . As a result, upon actuation of an open aisle push button switch  28  in the controller  26  located on mobile storage unit  22   f , the controller of mobile storage system  20  will generate a message indicating that the specified function cannot be performed. However, as illustrated in  FIG. 6 , once the person P has left aisle  34  and it is no longer occupied, aisle  34  can be closed in a subsequent action. 
     As illustrated in  FIGS. 6 and 7 , if a pair of operators would like to simultaneously open aisles between, for example, mobile storage units  22   b  and  22   c  and storage units  22   f  and  22   g , as shown at open aisle requests  31  and  32 , respectively, they would actuate the open aisle push button switches  28  in the controllers  26  located on mobile storage units  22   c  and  22   f , respectively. Once actuated, the logic system  58  of the mobile storage system  20  must again make a “decision.” The safety or surveillance unit  60  of the mobile storage system  20  will not detect the presence of an obstacle or object in open aisle  34 . Therefore, system  20  will move mobile storage unit  22   c  as well as the group of storage units  22   d - f  in order to simultaneously form aisles  40  and  42  illustrated in  FIG. 7 . Aisle  34  is closed by the movement of mobile storage unit  22   c  as well as the group of storage  22   d - f . The distance sensing unit  62  will split the MAS between the two aisles  40  and  42  such that each has a width of thirty inches. The operators now have access to aisles  40  and  42 . 
       FIGS. 8 and 9  illustrate another unique feature of the mobile storage system  20 , namely its ability to make “decisions” based on certain predetermined criteria, such as the frequency of use of a particular aisle. An intelligence unit  64  is included in the logic system  58  that maintains data regarding the frequency of use of a particular aisle. The frequency of use may be user defined, or may be determined on an ongoing basis by the intelligence unit  64  of logic system  58  based on information provided by the surveillance unit  60 . Alternatively, the predetermined criteria may be a default that is programmed or input into the controller of mobile storage system  20  that instructs the logic system  58  to maintain a certain aisle open whenever possible. 
     As illustrated in  FIG. 8 , aisles  40  and  42  are both open and unoccupied, and a user desires to open an aisle between mobile storage units  22   d  and  22   e . In the illustrated example, aisle  42  is more frequently used than aisle  40 , or is the aisle that has been designated to remain open whenever possible. When the operator wishes to open an aisle between mobile storage units  22   d  and  22   e , the operator presses an open aisle push button switch  28  in the controller  26  located on mobile storage unit  22   e . Once actuated, the intelligence unit  64  of the logic system  58  of the mobile storage system  20  must make a “decision” regarding which aisle to close. Because the safety or surveillance unit  60  of the logic system  58  indicates that both aisles  40  and  42  are unoccupied, it bases its “decision” on the predetermined criteria, e.g. the frequency of use of the respective aisles  40  and  42 . As noted above, aisle  42  is more frequently used than aisle  40 . Therefore, aisle  42  will remain open and aisle  40  will be closed to form aisle  44  as illustrated in  FIG. 9 . Aisle  40  is closed by the movement of mobile storage units  22   c  and  22   d  and aisle  44  is opened. The distance sensing unit  62  will split the MAS between the two aisles  44  and  42  such that each has a width of thirty inches. 
       FIGS. 10 and 11  illustrate a similar example of the controller of mobile storage system  20 , making a “decision” based on the predetermined criteria, e.g. frequency of use of a particular aisle. As illustrated in  FIG. 10 , aisles  44  and  42  are both open and unoccupied and a user desires to open an aisle between mobile storage units  22   a  and  22   b . In the illustrated example, aisle  44  is either designated as the aisle to remain open when possible, or is more frequently used than aisle  42 . Assuming an operator would like to open an aisle between mobile storage units  22   a  and  22   b , the operator presses an open aisle push button switch  28  in the controller  26  located on mobile storage unit  22   b . Once actuated, the intelligence unit  64  of the logic system of the mobile storage system  20  must make a “decision” regarding which aisle to close. Because the safety or surveillance unit  60  of the mobile storage system  20  indicates that both aisles  42  and  44  are unoccupied, it bases its “decision” on the predetermined criteria, e.g. frequency of use. As noted above, aisle  44  is more frequently used, therefore aisle  44  will remain open and aisle  42  will be closed to form aisle  46  illustrated in  FIG. 11 . Aisle  42  is closed by the movement of mobile storage units  22   e  and  22   f . Aisle  46  is opened by the movement of mobile storage units  22   b - d . Aisle  44  is maintained by the shifting of  22   b - d  and  22   e  and  22   f . The distance sensing unit  62  will split the MAS between the two aisles  46  and  44  such that each has a width of thirty inches. 
     While this feature of the present invention has been shown and described with respect to certain predetermined criteria, e.g. user designation or frequency of use, it is understood that any other criteria may be employed and that the criteria may be altered or changed by the user if desired. For example, the predetermined criteria may be based on the contents of the storage units, the locations of the storage units within the floor plan of the space within which mobile storage system  20  is located, etc. When a frequency of use criteria is employed, the logic system  58  functions to compare the relative frequency of use of the two open aisles when a user wishes to create an aisle between another pair of adjacent storage units. It should also be understood that various criteria may be used in combination in order for the logic system  58  to determine which of a pair of open aisles to close when a user wishes to create an aisle between a pair of closed storage units. 
     It can thus be appreciated that the mobile storage system  20  provides for a mobile storage system capable of providing simultaneous access to multiple aisles within the storage system as well as generating a single widened aisle. The maximum aisle space can be divided between a single widened wheelchair accessible aisle, or two narrower aisles. The system monitors the presence of individuals or objects located within an aisle, the distance between aisles and the most frequently used aisles, in order to make “intelligent,” safe decisions when opening or closing a particular aisle. As a result, system productivity and safety are increased. This is in contrast to mobile storage systems of the prior art, wherein the mobile storage units adjacent an open aisle are moved to close an aisle regardless of the frequency of use of the particular aisle. 
     While the system has been shown and described with respect to a specific embodiment, it is contemplated that certain details may vary from the specific construction as disclosed, while still falling within the scope of the present invention. Furthermore, the reference to “positions” throughout the application is for illustrative purposes and in no way limiting. Further, while the invention has been shown and described as having seven mobile storage units, it is understood that this number of mobile storage units is illustrative and that any other number of mobile storage units may be employed. Likewise, while the invention has been shown and described as having two narrower or one wide aisle any number of aisles could be generated within the system depending on the overall needs and use of the system. 
     Various alternatives and modifications are contemplated as being within the scope of the following claims, which particularly point out and distinctly claim the subject matter regarded as the invention.