Abstract:
An automated parts storage and retrieval method is provided. The method includes a frame, a plurality of trays configured to hold a plurality of parts, and a movement method attached to the frame and arranged to move the plurality of trays in a serpentine pattern for retrieval and storage of the plurality of parts. The movement method includes a plurality of sprockets arranged within the frame in a zigzag pattern, at least one chain toothedly engaged within the plurality of sprockets, and a drive motor configured to drive one of the plurality of sockets. The plurality of trays are rotatably attached to the at least one chain. The method includes a computer method for controlling the drive motor based on a selection using a parts selection component and position information sent by a position sensor.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to storage and retrieval systems and, more specifically, to automated parts storage and retrieval systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many manufacturing processes entail steps that include a choice of a great number of different kinds or types of parts. The parts must be readily available to the people performing the manufacturing process steps in order for the manufacturing process to be as efficient as possible.  
           [0003]    Many times, due to the vast amounts of different types of parts, the parts can be difficult to find because they are stored in various bins located in several places on a factory floor. The more time that is spent looking for parts, the longer it takes to manufacture the product, thereby increasing the cost of the product. Also, facilities that are used for holding vast amounts of parts take up valuable floor space. The parts are stored in opened containers, thus exposing the parts to a factory floor environment and requiring the parts to be cleaned before use. Cleaning of parts causes even more delays as well as unnecessarily exposing employees to cleaning solvents.  
           [0004]    An example of this manufacturing process is presented by aircraft manufacturing. For example, over 900 different, prefabricated shims are stored in cardboard boxes on roller racks on a factory floor. The shims get dirty due to being exposed to a machine shop-like factory floor environment and must be cleaned thoroughly before application. The roller racks that hold the cardboard boxes take up hundreds of square feet of floor space.  
           [0005]    Various proposals have been presented for more efficiently storing and retrieving parts. However, in a manufacturing process that entails extremely large numbers of parts, the storage and retrieval device that have been proposed take up large areas of floor space or are very tall and bulky. It is difficult and expensive to redesign a factory floor to accommodate a storage and retrieval device that is tall and bulky. Further, it is very difficult to move such a device easily and efficiently around the factory floor.  
           [0006]    Therefore, there exists an unmet need for an automated storage and retrieval system that takes up less space, keeps parts clean, aides in organizing and stabilizing inventory, and is easily movable about a factory floor.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention provides an automated parts storage and retrieval system. The system of present invention more efficiently stores large numbers of parts in a single unit that is easy to access, maintains clean parts, and is easy to move about a factory floor with existing equipment.  
           [0008]    One embodiment of the system includes a frame, a plurality of trays configured to hold a plurality of parts, and a movement system attached to the frame and arranged to move the plurality of trays in a serpentine pattern for retrieval and storage of the plurality of parts. The movement system includes a plurality of sprockets arranged within the frame in a zigzag pattern, at least one chain toothedly engaged within the plurality of sprockets, and a drive motor configured to drive one of the plurality of sockets.  
           [0009]    According to an aspect of the invention, the plurality of trays are rotatably attached to the at least one chain.  
           [0010]    Another aspect of the system includes a computer system for controlling the drive motor based on a selection using a parts selection component and position information sent by a position sensor.  
         BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]    The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.  
           [0012]    [0012]FIG. 1 is a perspective view of the present invention;  
           [0013]    [0013]FIG. 2 is a block diagram of an automated storage and retrieval system formed in accordance with the present invention;  
           [0014]    [0014]FIG. 3 is a perspective skeletal view of the present invention;  
           [0015]    [0015]FIG. 4 is a perspective view of the drive mechanisms for the present invention;  
           [0016]    [0016]FIG. 5 is a perspective view of drive shaft supports;  
           [0017]    [0017]FIG. 6 is a side view of a portion of the present invention;  
           [0018]    [0018]FIG. 7 is a perspective view of a connection between a chain and a parts tray; and  
           [0019]    [0019]FIG. 8 illustrates a graphical user interface formed in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 1 illustrates a perspective view of an automated storage and retrieval device  20 . The device  20  includes a main housing  60  that includes the chains, sprockets, and trays. Adjacent to the main housing  60  is a smaller housing section  64  that stores the encoder  34 , the drive motor  36 , the controller  32 , and the computer  30 . On top of the section  64 , suitably at a comfortable standing position for user interaction, is a display  48  and a user interface  46 . The device  20  includes forklift footings  88  attached to the base of the housing  60  that are sized to receive forklift forks. Lifting hooks (not shown) are attached to the top of the housing  60 .  
         [0021]    A parts selection window  80  is located on a front face of the housing  60 . Upon selection of a part using the computer  30 , the tray containing the part is moved to the window  80 .  
         [0022]    [0022]FIG. 2 illustrates a block diagram of the non-limiting example automated storage and retrieval system  20  that stores and provides automated access to large amounts of parts in a small space. The system  20  includes a computer  30  that is suitably coupled to a controller  32 . The controller  32  and the system  20  are coupled to a chain and sprocket tray movement system  40 . The chain and sprocket tray movement system  40  include an encoder  34  and a drive motor  36 . The chain and sprocket tray movement system  40  also includes one or more chains that serpentine around sprockets. The chains support trays that support part bins. The chain, sprockets, trays, and bins are shown in the following figures. The computer  30  includes a processor  44  that is coupled to the user interface  46 , and a display  48 . The computer  30  is suitably a programmable logic controller (PLC), such as that produced by Allen-Bradley, Inc.  
         [0023]    In one non-limiting embodiment, the computer  30  is preprogrammed to identify what parts are located on what tray within the system  20 . The encoder  34  provides a position signal that indicates the position of the trays within the chain and sprocket tray movement system  40 . The computer  30  receives the position signal from the encoder  34 . The user, using the user interface  46 , makes a request for a part by interacting with the user interface  46  and the display  48 . The processor  44  sends a control signal to the controller  32  based on the request and the position signal. The controller  32  converts the control signal from the processor  44  into electrical signals for the drive motor  36 . The drive motor  36  then moves the chain accordingly.  
         [0024]    The following figures illustrate a non-limiting example embodiment of the automated storage and retrieval system  20 . FIG. 3 illustrates a skeletal view of the housing  60 . The housing  60  is suitably formed of a welded aluminum internal frame  100  that supports the sprockets. In FIG. 3, trays are not shown for clarity purposes. The housing  60  includes first and second chain/sprocket sections  102   a  and  102   b . The first and second chain/sprocket sections  102   a  and  102   b  are located on opposing sides of the frame  100 . The first side of the frame  100  includes a forward vertical beam  103   a  and an aft vertical beam  104   a . The second side of the frame  100  includes a forward vertical beam  103   b  and an aft vertical beam  104   b . A drive shaft  106  passes through the forward vertical beams  103   a,b  and are attached to drive sprockets  108   a,b  near the beams  103   a,b , respectively. Upper forward sprockets  110   a,b  are rotatably mounted to an upper portion of the forward vertical beams  103   a,b , respectively. Upper aft sprockets  120   a,b  (b is hidden by the frame  100 ) are rotatably attached to the aft beams  104   a,b , respectively, at approximately the same height as the sprockets  110   a,b.    
         [0025]    Upper middle sprockets  124   a,b  (b is hidden by the frame  100 ) are rotatably attached to the frame  100  between the sprockets  110   a,b  and sprockets  120   a,b , respectively. Middle aft sprockets  130   a,b  are rotatably attached to the frame  100  slightly below the upper middle sprockets  124   a,b  and slightly closer to the aft beam  104   a,b , respectively. Lower middle sprockets  134   a,b  are rotatably attached to the frame  100  directly below the upper middle sprockets  124   a,b , below Middle aft sprockets  130   a,b , and above the drive sprockets  108   a,b . Lower aft sprockets  140   a,b  are rotatably attached to the aft beam  104   a,b  at the same height as the drive sprockets  108   a,b.    
         [0026]    Chains  146   a,b  run through each set of sprockets in the following order:  108   a,b ,  110   a,b ,  120   a,b ,  124   a,b ,  130   a,b ,  134   a,b ,  140   a,b , then back to  108   a,b . The location of the sprockets is optimized based on the size of the trays that will connect to the chains. The chains and sprockets guide the trays through the housing  60  in a pattern that most efficiently uses the volume of space within the housing  60 . An example pattern is a zigzag or serpentine pattern that moves the trays through the volume of the housing  60  without running into other trays. Thus, the housing  60  holds a large amount of parts without occupying too much floor space or extending too high vertically.  
         [0027]    [0027]FIG. 4 illustrates a dampening device  150  that attaches between the shaft  106  and a shaft  152  from a drive motor  36   a . The shaft  106  passes through an encoder  34   a , then through a pillow block bearing assembly  156  mounted in the beam  103   a . The dampening device  150  dampens any sudden movements created by the motor  36   a  thereby smoothly starting and stopping the shaft  106 . The encoder  36   a  detects rotations of the shaft  106  and sends that information to the computer  30  through a data port. A non-limiting example of the drive motor  36   a  is an Alling-Lander DC motor. A non-limiting example of the dampening device  150  is a Zero-max coupler. A non-limiting example of the encoder  34   a  is a Dynapar encoder.  
         [0028]    As shown in FIG. 5, the shaft  106  is supported between the drive sprockets  108   a,b  by a pair of bearing shaft supports  180  and  182 . The shaft supports  180  and  182  are attached to the frame  100  (not shown).  
         [0029]    [0029]FIG. 6 illustrates a side view of the chain and sprocket tray movement system  40 . Trays  200  rotatably hang from opposing pins on each of the chains  124   a,b . Each tray  200  is attached at opposite ends to the chains  124   a,b  in order to be level. The rotatably attached trays  200  are spaced apart enough to allow free-hanging motion throughout the travel of the chains  124   a,b . As the chains  124   a,b  moves around the sprockets, the trays  200  move about the space within the frame  100 . Bins  204  rest on the trays  200 .  
         [0030]    [0030]FIG. 7 illustrates attachment of each tray  200  to the chains  124   a,b . Each tray  200  includes a base  202  (FIG. 6) and end walls  206  that attach to the base  202 . An opening  210  in the end walls  204  receives a bolt  214  that attaches to a pin in the chain or is an extension of the pin in the chain. A spacer  212  is placed between the end walls  206  and the chains  124   a,b . The spacer  212  allows movement of the tray  200  about the bolt  214 , thereby allowing the tray to hang from the bolt  214 . In one non-limiting example, the Chains  146   a,b  are suitably standard ANSI  60  chains of equal length with {fraction (1/4)} inch integrated rivet/pin for attaching the trays. The trays are suitably made of stainless steel and the bins are made of plastic.  
         [0031]    [0031]FIG. 8 illustrates a user interface display window  250  that is presented on the display  48 . The user interface window  250  includes a pull-down scrollable window  256  that allows a user using a user interface device  46  to select parts that are stored within the system  20 . Once the user selects the parts from the list presented in the window  256 , the computer  30  generates a control signal that ends up causing the chain and sprocket tray movement system to rotate to present the tray that includes the selected part within the window  80  of the housing  60 .  
         [0032]    While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.