Abstract:
An overhead conveyor system transports a selectable workpiece from vertically extending storage racks having a plurality of horizontally extending shelves with stationary stacks of workpieces to be processed on each shelf. Each shelf includes horizontally spaced shelf support members defining openings complementary to horizontally extending support members of a carriage. The horizontally extending members of the carriage are insertable between adjacent horizontally spaced shelf members to engage the upper most workpiece supported by the shelf located below the horizontally extending support members of the carriage. Workpiece engaging members operably associate or engage the upper-most workpiece with the carriage for movement vertically and horizontally along the path of travel to a workstation for processing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of provisional application Ser. No. 60/345,498 filed on Nov. 9, 2001. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a storage and retrieval system capable of horizontal and vertical movement components to operably engage relatively large planar sheets of material from a plurality of vertically spaced storage locations for delivery to one or more workstations, such as a laser cutting workstation. 
     BACKGROUND OF THE INVENTION 
     Laser cutting workstations come in a variety of styles, sizes, and shapes from a wide variety of commercial manufacturers. Each laser machining cell is typically supplied with a stream of workpieces to be processed by a conveyor system. Typical conveyor systems for laser machining workstations can be seen in U.S. Pat. Nos. 5,192,848; 5,310,396; 5,121,539; 4,735,539; and commercially available units are manufactured by Trumpf GmbH &amp; Co, Ditzingen, of the Federal Republic of Germany. 
     Most of these configurations require complicated shuttle systems to move parts from vertical spaced storage locations to a ready position to be engaged by the conveyor system, since the conveyor system is incapable of operably engaging and removing the workpieces from the vertical storage locations directly. 
     SUMMARY OF THE INVENTION 
     It would be desirable in the present invention to provide a workpiece conveyor system capable of operably directly engaging relatively large planar workpieces within vertically extending spaced storage locations or racks, and for moving the workpieces or plates from the storage location to a workstation with a single conveyor system. It would be desirable in the present invention to eliminate the need for any intermediate shuttle or auxiliary movable elements to bring the workpieces into a ready position for attachment by the conveyor system. In other words, it would be desirable in the present invention to have the workpieces stored in a vertically extending spaced rack system where the storage location of each workpiece is a ready position that can be accessed directly by the conveyor system for operably engaging and moving the workpiece from the particular storage location to the workstation for processing. 
     A superstructure includes columns supporting an overhead runway system similar to a conventional bridge crane structure. The shelving is constructed in a manner that accommodates the carriage. The carriage arms are equally spaced to go in between the shelf supports. Once the carriage has been positioned into the shelf unit the carriage is then lowered down to the material. The suction cups that are attached to the carriage are then activated by a vacuum pump and attach themselves to the process sheets. The material being processed is raised, and then transferred to the laser bed. The trolley travels left or right to position the material over the laser bed. The sheet steel is then lowered onto the laser bed. A column on the trolley serves as a guide to raise and lower the carriage. The column stabilizes the carriage load; the column and carriage are offset from the trolley to evenly distribute the carried load. The carriage is raised and lowered by nylon and/or polyester straps that are rolled onto a drum. The carriage travels vertically to allow the hoist to access multiple shelves. Since the equipment travels on a runway system that is expandable, it is capable of supplying one or more lasers (or other processing machines). 
     The vacuum carriage goes into the shelves to retrieve sheets with other systems, sheets are transferred from the rack out to the carriage versus the carriage retrieving the sheets while in the rack. The carriage can access multiple shelves. The fixed shelves are spaced to accommodate the vacuum carriage. The carriage is raised and lowered via nylon, and/or polyester straps which are rolled onto a drum. Six (6) directions of travel, forward, backward, left, right, up and down are provided by the combination of the shuttle/trolley and carriage. A series of vacuum cups are used to hold the product (sheets) as it travels from the shelves to the laser bed. A remote control station controls the apparatus. 
     The runway is the superstructure that supports the bridge similar to a conventional overhead bridge crane superstructure. The bride is the structure that travels along the runway, and also supports the trolley. The trolley is the structure that travels horizontally along the bridge and supports the carriage. The carriage is the structure that travels vertically on the column of the trolley, which supports a series of vacuum cups. The vacuum cups are rubber type suction cups that adhere to any flat surface such as sheets of steel, glass, plastic, etc. The shelves are a series of sheet storage shelves where the raw material (sheets) are stored for processing. 
     Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
     FIG. 1 is a perspective view of a conveyor according to the present invention; 
     FIG. 2 is a perspective view of a photograph of a conveyor according to the present invention with the workpiece support members positioned within the vertically spaced storage system for retrieving a workpiece to be transported; and 
     FIG. 3 is a close-up perspective view of the conveyor according to the present invention illustrated in FIG. 2 prior to attachment to the workpiece for transport. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1-3, a laser cutter plate conveyor  10  according to the present invention includes a frame structure  12 . The frame structure  12  can include at least one, and preferably two spaced apart, horizontally extending frame members or rails  14 . A trolley or shuttle  16  is supported on the frame members or rails  14  for movement along a fixed path of travel defined by the frame members or rails  14 . Drive means  18  is provided operably connected to the shuttle  16  for moving the shuttle  16  between first and second end limits of travel along the horizontally extending frame member or rail  14 . By way of example and limitation, the drive means  18  can include a reversible electric motor  20  for driving the shuttle  16  between the first and second end limits of travel along the fixed path defined by the horizontally extending frame member or rail  14 . Control means  22  can be provided operably connected to the drive means  18  of the shuttle  16  for controlling movement of the shuttle  16  along the fixed path of travel defined by the horizontally extending frame member or rail  14 . Appropriate signal generators, such as switches or sensors, can be provided as required along the fixed path of travel for indicating the location of the shuttle  16  as the shuttle  16  moves along the fixed path allowing the control means  22  to control the speed and the position of the shuttle  16  along the fixed path of travel for stopping at either the first or second end limit of travel, or any workstation defined in between the end limits of travel. 
     The shuttle  16  includes at least one vertically extending support member  24 . A carriage  26  is supported for movement along the vertically extending support member  24 . Lift means  28  is provided for moving the carriage  26  vertically along the vertically extending support member  24  between a lowest position and a highest position. The lift means  28  can include one or more nylon or polyester straps or belts extendable and retractable with respect to a drum or spool with a reversible drive motor controlled by the control means  22 . Appropriate signal generators, such as sensors or switches, can be provided for identifying various vertical positions along the vertically extending support member  24  allowing the control means  22  to control the speed and position of the carriage  26  as the carriage  26  moves along the vertical path defined by the vertically extending support member  24 . The carriage  26  can include a plurality of horizontally extending support members  30 . A plurality of workpiece engaging members  32  are connected to the horizontally extending support members  30 . The workpiece engaging members  32  can be of any known configuration suitable for lifting relatively large, heavy, metal plates. By way of example and not limitation, the workpiece engaging members  32  can include magnetic and/or vacuum suction cup forms of engagement members. The magnetic and/or vacuum actuation can be controlled in response to appropriate signals from the control means  22  in order to engage and lift a workpiece from the vertically extending storage rack  34  for movement along the fixed path of travel to the workpiece bed or support nest  36  of the laser cutting apparatus. 
     In the illustrated embodiment, the vertically extending storage rack  34  can be connected to and form part of the frame structure  12 . The storage rack  34  can include a plurality of vertically spaced shelves  38 . Each shelf  38  can support a vertical stack of workpieces to be processed as best seen in FIG.  3 . Each shelf  38  is defined by a plurality of horizontally spaced shelf members  40 . The horizontally shelf members  40  define openings in between one another at the ends facing the side of approach by the carriage and associated plurality of horizontally extending support members  30 . The spacing defined by the horizontal shelf members  40  is complementary allowing entry of the horizontally extending support members  30  of the carriage  26  permitting direct engagement with the upper-most workpiece in the stack supported on that particular shelf as best seen in FIG.  3 . This complementary configuration eliminates the need for additional shuttle units to move each individual plate from the storage location to a position accessible by the overhead conveyor system. In operation, the vertically extending storage rack  34  is loaded with workpieces to be processed. The shelves can support a stack of identical workpieces on each shelf, or each shelf can be allocated a workpiece of a particular material or thickness to be processed. The particular location of the workpiece to be processed can be programed into the control means  22 . When the laser cutting apparatus calls for a new workpiece to be processed, the control means  22  determines the shelf location of the appropriate workpiece to be retrieved, and moves the carriage  26  to the appropriate elevation for entry above the shelf unit containing the workpiece to be retrieved. After the appropriate elevation of the carriage  26  has been set, or simultaneously while moving the carriage  26 , the shuttle  16  can be activated to move from the present or current position toward the vertical storage rack  34 . If necessary, the shuttle  16  can be stopped prior to entering into the vertical storage rack  34  if the carriage  26  has not reached the appropriate elevation for entry into the shelf holding the workpiece to be retrieved. When the carriage  26  is in the appropriate elevation to enter the shelf supporting the workpiece to be retrieved, the shuttle  16  continues toward the storage rack  34  inserting the horizontally extending support members  30  within the complementary open spaces of the horizontally spaced shelf members  40 . When fully inserted, the carriage  26  is lowered into engagement with the upper-most workpiece supported on the shelf in response to appropriate signals by the control means  22 . The control means  22 , then activates the engaging members  32  to attach to the workpiece to be transferred. The carriage  26  is then raised slightly to lift the engaged workpiece from the stack supported by the shelf and the shuttle  16  is then sequentially, or simultaneously, moved along the fixed path of travel defined by the horizontally extending frame members or rails  14  of the frame structure  12 . After reaching the laser cutter workstation position, the shuttle unit  16  is stopped in response to appropriate signals from the control means  22 . The carriage  26  is then actuated to lower the engaged workpiece to the workpiece bed or support nest  36  of the laser cutter apparatus. After the workpiece is engaged with the workpiece bed or support nest  36 , the control means  22  sends the appropriate signal to disengage the engaging members  32 , ending the transport cycle. The carriage is then moved vertically away from the workpiece that has been transported, and sequentially or simultaneously, the shuttle  16  is operated to remove the conveyor away from the laser cutter workstation allowing the processing to begin. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.