Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority from United States provisional application No.  
         [0002]    [0002] 60 / 191 , 919  filed on Mar. 24, 2000. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0003]    1. Field of the Invention  
           [0004]    This invention relates to methods for making pallets, and more particularly, to a method and apparatus for boring and bolting pallets.  
           [0005]    2. Related Art  
           [0006]    Wooden pallets for transporting and storing goods are widely used in commerce and industry. Due to heavy loads and rough handling, pallets are frequently destroyed or damaged and generally have a relatively short useful life. Therefore, a continuous supply of substantial quantities of new replacement pallets is needed in industries which involve bulk storage and handling operations.  
           [0007]    Conventional pallets have a plurality of wooden components that are nailed or bolted together. Such conventional bolted pallet construction processes require each component of a pallet to be drilled separately, then the pallet is assembled using bolts at a later date. Problems arise with the assembly in that the holes in joining components may or may not align properly. If mis-aligned, the edges of the components of the resulting pallet will not be flush. Moreover, even if one could drill the holes in exactly the right location it would be very time consuming to line up all of the parts and holes so as to bolt the parts together with proper alignment.  
           [0008]    Therefore, there is a need for an apparatus and process in which a wooden pallet is drilled quickly and efficiently such that when bolted together, all joining components of the pallet are aligned properly resulting in flush edges.  
           [0009]    In addition, conventional bolted pallets use step drills for drilling the bores in the pallet. Step drills are known in the prior art and are commercially available; however, such step drills only have two diameters. Therefore, the resulting bore from a conventional step drill does not provide a means for making the head of a bolt recessed within, or flush with, a panel top component. By only providing a bore with two diameters, the head of a bolt must rest on the top surface of a panel top component. Therefore, when moving a pallet, the head of the bolt will catch on objects and make it difficult to slide or move a pallet in and out of different positions.  
           [0010]    Therefore, there is a need for an apparatus and process in which the bores of a pallet are drilled having three diameters, thereby allowing the head of a bolt to be recessed in, or flush with, the top surface of a panel top component of the pallet.  
         SUMMARY OF THE INVENTION  
         [0011]    The present invention solves the problems encountered with previous efforts at manufacturing bolted pallets by providing a method and apparatus that can quickly position pallet components in an assembly jig, drill bores through joining components simultaneously, and keep the components in place while the pallet is bolted together.  
           [0012]    The apparatus for boring and bolting pallets includes a means for loading an assembly jig with two or more main components, two or more cross components, a plurality of spacer support components, and a panel top component (collectively, components). The assembly jig holds the main components, cross components, spacer support components, and panel top component in proper position to form an incomplete pallet. The apparatus also includes a means for simultaneously boring each intersection of a main component, spacer support component, cross component, and panel top component of the incomplete pallet while the incomplete pallet is being contained in the assembly jig. The boring of the components is accomplished by raising a plurality of drills from below the incomplete pallet. After drilling the bores from below, the assembly jig contains a bored pallet wherein all of the needed bores have been drilled concurrently. The apparatus also includes a means for delivering the assembly jig containing the bored pallet to a bolting table where the main components are bolted to the cross components, the spacer support components, and the panel top component, resulting in a bolted pallet or pallet. Once the pallet is removed from the assembly jig, the apparatus can include a means for returning the assembly jig to the means for loading in order to receive new components for a new pallet.  
           [0013]    The method for boring and bolting pallets includes filling an assembly jig located at a pre-boring station with two or more main components, two or more cross components, a plurality of spacer support components, and a panel top component to form an incomplete pallet; simultaneously boring the intersections of the main components, the cross components, the spacer support components, and the panel top component of the incomplete pallet, resulting in a bored pallet form; delivering the assembly jig containing the bored pallet form to a bolting table; and bolting all of the components together to create a pallet. The method can also include means for removing the pallet from the assembly jig, and a means for returning the assembly jig to the pre-boring station in order to receive new components for a new pallet.  
           [0014]    The present invention uses a drill bit having three different diameters, resulting in a bore having corresponding three different diameters. This provides the means for the head of the bolts to be recessed in, or flush with, the exterior surface of the pallet. The advantage of recessed bolts is that the pallet can be easily slid into position without the bolt heads catching on anything and interfering with the moving of the pallet.  
           [0015]    As a result of the boring and bolting process, a pallet is produced that has two or more main components, two or more cross components, and a panel top component, thereby creating four or more intersections of the main components, the cross components, and spacer support components. The pallet has a bore centrally located at each of the main component/cross/spacer support component intersections with a bolt inserted through each bore. Each bolt is secured with a pallet nut such that the head of the bolt and the pallet nut are countersunk below the exterior surface of the pallet.  
           [0016]    An advantage of the present invention is that the external edges of the pallet are flush—meaning that the panel top component, cross components, spacer support components, and main components are flush with one another such that no one component protrudes beyond any of the others. This can be done without grossly over-sizing the bores which makes the joints of the pallet loose and weak.  
           [0017]    A second advantage of the present invention is that all bores of a pallet are drilled simultaneously and with precision resulting in a pallet being assembled quickly and efficiently because all components are automatically aligned. In operation, it has been shown that the present invention results in more pallets being made in fewer man hours, thereby reducing the labor cost of pallet construction. 
       
    
    
     BRIEF DESCRIPTION OF FIGURES  
       [0018]    The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.  
         [0019]    [0019]FIG. 1 is a planar diagram showing a side view of a boring machine of the present invention;  
         [0020]    [0020]FIG. 2 is a planar diagram showing a top view of the apparatus of the present invention for manufacturing pallets;  
         [0021]    [0021]FIG. 3A is a planar diagram showing a side view of a boring machine table of the present invention;  
         [0022]    [0022]FIG. 3B is a planar diagram showing a bottom view of the boring machine table;  
         [0023]    [0023]FIG. 4A is a planar diagram showing a bottom view of the boring machine table with a dust collector system of the present invention;  
         [0024]    [0024]FIG. 4B is a planar diagram showing a side view of the boring machine with a motor system;  
         [0025]    [0025]FIG. 4C is a planar diagram showing a bottom view of the boring machine table with a lift assembly of the present invention;  
         [0026]    [0026]FIG. 4D is a planar diagram showing a front view of the boring machine with the dust collector system and the motor system;  
         [0027]    [0027]FIG. 5A is a planar top view of a bolting table of the present invention;  
         [0028]    [0028]FIG. 5B is a planar front view of the bolting table;  
         [0029]    [0029]FIG. 5C is a planar side view of the bolting table;  
         [0030]    [0030]FIG. 6A is a planar side view of an assembly jig of the present invention;  
         [0031]    [0031]FIG. 6B is a planar front view of the assembly jig;  
         [0032]    [0032]FIG. 7 is a planar side view of the bolting table showing the raising/lowering assembly;  
         [0033]    [0033]FIG. 8A is a perspective diagram of a bored pallet of the present invention;  
         [0034]    [0034]FIG. 8B is a planar diagram showing the cross-section of an intersection of a bored pallet; and  
         [0035]    [0035]FIG. 9 is a planar diagram showing a drill bit of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0036]    FIGS.  1 - 9  show the preferred method and apparatus for manufacturing bolted pallets wherein all of the components of the pallet are bored and bolted at one time.  
         [0037]    In the preferred embodiment, an operator loads an assembly jig (or jig)  600  with a plurality of components. In the preferred embodiment, the components comprise at least two main components  818  (bottom boards), and at least two cross components  816  (connectors), wherein a spacer support component  812  (block) is inserted between each main component  818  and each cross component  816  at every intersection. Furthermore, a panel top component (overlay)  814  of panel board or other material known to one of ordinary skill in the art is placed over the cross components  816 . See FIG. 8. The preferred components are described in these terms for convenience purpose only. It would be readily apparent for one of ordinary skill in the relevant art to use the present invention in constructing a pallet having only two or more main components  818  and two or more cross components  816 , and optionally including any additional component, e.g., a spacer support component  812  or a panel top component  814 .  
         [0038]    In the preferred embodiment, a pallet of the present invention is manufactured of all wood pieces; however, this is for convenience purpose only. It would be readily apparent to one of ordinary skill in the relevant art to use the present invention with a pallet of a different material, e.g., plywood, oriented strand board, plastic, composite materials, or a combination thereof.  
         [0039]    An assembly jig  600  of the present invention has four walls, e.g. a first wall  602  and a second wall  606 , which may by dynamically adjustable to accommodate a pallet of any size. In addition, the assembly jig  600  has a locking bar  604  for holding the components in place within the assembly jig  600 . In operation, the locking bar  604  is raised. Once the components are inserted in the assembly jig  600 , the locking bar  604  is lowered, thereby clamping the components in position.  
         [0040]    Also for convenience only, when an operator properly “loads” an assembly jig  600  with main components  818 , cross components  816 , spacer support components  812 , and a panel top component  814  (collectively, components), an incomplete pallet is created and contained in the assembly jig  600 . After the bores  806  are drilled through the components at each intersection, a bored pallet  800  is created and contained in the assembly jig  600 . After the bolts are inserted and fastened through each bore  806 , a pallet is created and removed from the assembly jig  600 .  
         [0041]    [0041]FIG. 8B is a cross section of an intersection of a bored pallet  800  of the present invention, showing the preferred shape of a bore  806 . In the preferred embodiment, the bore  806  of the present invention has three different diameters: ⅜″, {fraction (9/16)}″, and 1 ⅛″. This preferred bore  806  is made using a preferred drill bit  900  of the present invention as shown in FIG. 9, wherein the drill bit  900  provides the three different diameters. The drill bit  900  comprising a first bit means  902  for creating a bore  806  having a first diameter, e.g., ⅜″, a second bit means  904  for creating a bore  806  having a second diameter, e.g., {fraction (9/16)}″, and a third bit means  906  for creating a bore  806  having a third diameter, e.g., 1 ⅛ . The third diameter of the bore  806  is made by rigidly attaching, such as by using two or more screws, a third bit means  906  to the shaft  908  of the drill bit  900 . Therefore, when the drill bit  900  engages an intersection of an incomplete pallet, the first bit means  902  makes a first diameter portion  802  of the bore  806 , the second bit means  904  makes a second diameter portion  808  of the bore  806 , and the third bit means  906  makes a third diameter portion  810  of the bore  806 . It is the second diameter portion  808  and third diameter portion  810  that allow a pallet nut to be recessed below the exterior surface of the pallet  800 .  
         [0042]    A preferred embodiment of a boring machine  100  of the present invention for simultaneously boring holes  806  into all of the intersections between main components  800  and cross components  816  of an incomplete pallet is shown in FIG. 1. The boring machine  100  has a means for receiving an empty assembly jig  600 , a means for loading the empty assembly jig  600  with components to create an incomplete pallet, a means for simultaneously boring the bores  806  in an incomplete pallet to create a bored pallet  800 , a means for delivering the bored pallet  800  to a bolting table  500  where a bolter installs a bolt into each bore  806  in the bored pallet  800 . Also, in the preferred embodiment, the present invention includes a means for returning an empty assembly jig  600  once a bolter removes the pallet from the assembly jig  600 .  
         [0043]    The preferred means for receiving an empty assembly jig  600  comprises an upper, or second, conveyor system  108  positioned above the boring machine  100  which moves in a horizontal plane longitudinally towards an operator standing at the loading end  118  of the boring machine  100 . When needed, the operator advances an empty assembly jig  600  from the upper conveyor system  108  on to a vertically adjustable table  102  that is in the raised position such that the table  102  is aligned with the upper conveyor system  108 . The operator then lowers the vertically adjustable table  102  with the assembly jig  600  disposed thereon to a lower, or first, conveyor system  116 . The lower conveyor system  116  moves in a horizontal plane longitudinally toward the rear end  120  of the boring machine  100 .  
         [0044]    A means for loading the empty assembly jig  600  with components to create an incomplete pallet comprises the vertically adjustable table  102  of the boring machine  100  on which an empty assembly jig  600  rests while being loaded with components. Once an operator has installed all of the components and makes an incomplete pallet, and the drilling portion  122  of the boring machine  100  is empty, the operator engages the lower conveyor system  116  to move the incomplete pallet into the drilling portion  122 .  
         [0045]    In the preferred embodiment, a means for simultaneously boring the bores  806  in an incomplete pallet to create a bored pallet comprises nine (9) drill bits  900  that drill bores  806  into the incomplete pallet, one in each intersection, from underneath the incomplete pallet. That is, a boring machine table  300 , having nine motors  404 , showing only a subset of motors  404   a - f  for convenience purpose only, attached thereto wherein each motor  404  is coupled to a drill bit  900 , is raised from under the assembly jig  600  such that each drill bit  900  drills a bore  806  into an intersection of the incomplete pallet. Specifically, a drill bit  900  raises through a hole  304  in the boring machine table  300  wherein a motor  404  is mounted to a motor mounting  302  on the bottom of the boring machine table  300 .  
         [0046]    In the preferred embodiment, a motor  404  is a 2 horsepower C-face motor and the boring machine table  300  is a 1″ thick machined steel table. Also in the preferred embodiment, the process for boring the incomplete pallets takes about four passes of the drill bits  900  to make a bore  806  of the needed shape and dimensions. The boring machine table  300  is raised and lowered by a system using a plurality of threaded rods  410   a - d,  one in each corner of the boring machine table  300 , which are connected via a chain  406  and one or more sprockets  408 . A hydraulic motor approximately centered underneath the boring machine table  300  drives the sprocket  408 f which in turn moves the chain  406 , thereby turning the threaded rods  410   a - d  and moving the boring machine table  300  up and down. FIG. 8B shows a profile of a single bore  806  for convenience purpose only. The discussion pertaining to the drilling of a single bore  806  is equally applicable to all bores  806  drilled into an incomplete pallet.  
         [0047]    The present invention is described in these terms for convenience purpose only. It would be readily apparent for one of ordinary skill in the relevant art to use a comparable motor  404 , drill bit  900 , and system for raising and lowering the boring machine table  300 .  
         [0048]    In the preferred embodiment, the boring machine  100  also incorporates a dust collection system comprising a plurality of tubes  402  connected to a vacuum system such that as the drilling machine  100  bores the bores  806 , the tubes  402  collect some of the resulting dust and shavings from the drilling process.  
         [0049]    A means for delivering the assembly jig  600  containing a bored pallet to a bolting table  500  where two bolters install bolts into each bore  806  in the bored pallet comprises a first conveyor system  208 . A means for returning an empty assembly jig  600  once the bolters remove the pallet from the assembly jig comprises a second conveyor system  206 , wherein the first conveyor system  208  and the second conveyor system  206  are vertically separated by about 12 inches. In operation, the bolters move the assembly jig  600  with the bored pallet off the first conveyor system  208  and onto the bolting table  500 .  
         [0050]    In the preferred embodiment, the bolting table  500  has a recessed table face  506  that is generally rectangular in shape with nine (9) hex-shaped blades  502  extending upwards off the table face  506 . The nine (9) hex-shaped blades  502  are configured such that they align with the nine (9) bores  806  in the bored pallet. Prior to the bolters moving the assembly jig  600  containing the bored pallet onto the bolting table  500 , the bolters place a Dynacast pallet nut onto each blade  502 . Therefore, when the assembly jig  600  with the bored pallet is moved onto the bolting table  500 , each of the nine pallet nuts is properly positioned under a bore  806  of the bored pallet. The bolting table  500  also comprises a means for aligning  504  an assembly jig  600  containing a bored pallet on the top of the bolting table  500 . The means for aligning  504  allows the assembly jig  600  to easily roll off of the first conveyor system  208  via wheels  510   a, b  and align the bores  806  of the bored pallet directly over the hex-shaped blades  502  with pallet nuts. In the preferred embodiment the means for aligning are a plurality of stops  504   a - d . The position of the stops  504   a - d  on the bolting table  500  may or may not be adjustable to accommodate pallets of varying sizes. For convenience purpose only, FIG. 5C shows a single hex-shaped blade  502  extending through the bolting table  500  with a pallet nut  512  disposed thereon.  
         [0051]    The bolting table  500  also comprises a means for raising and lowering the assembly jig  600  containing the bored pallet  800  so as to insert the nine pallet nuts into the bores  806  in the bored pallet  800 . See FIG. 7 wherein the assembly jig  600  is not shown for convenience purpose only. In the preferred embodiment, the means for raising and lowering the assembly jig  600  comprises four air cylinders  702   a,b  and two (2) sets of rollers  704  that support the assembly jig  600  and bored pallet  800 . Once the assembly jig  600  with the bored pallet  800  is in place on the bolting table  500 , a bolter operates a foot petal  706  for engaging the air cylinders  702  in order to lower the assembly jig  600  and the bored pallet  800  onto the bolting table  500 , thereby inserting the pallet nuts into the bores  806  of the bored pallet  800 .  
         [0052]    The hex-shaped blades  502  of the bolting table  500  also provide a means for preventing the pallet nuts from rotating while a bolt is being installed from above. That is, after the pallet nuts are inserted into the bores  806 , the bolters place a bolt into each bore  806  and use air impact wrenches to tighten the bolt through the bore  806  and into the pallet nut. In the preferred embodiment, the means for preventing the pallet nuts from rotating is the hex-shaped blades  502 . Because the blades  502  are hex-shaped, they fit within the hex-shaped holes of the pallet nuts, thereby immobilizing them and preventing their rotation, as a bolt is inserted and tightened.  
         [0053]    Once the nine (9) bolts are inserted and tightened in the nine (9) bores  806  of the bored pallet, the bolter operates the foot pedal  706  a second time, thereby engaging the air cylinders  702   a,b  to raise the assembly jig  600  containing a complete pallet above the hex-shaped blades  502 . Therefore, the air cylinders  702   a, b  provide the means for raising and lowering the assembly jig  600  above the hex-shaped blades  502 . The bolters then remove the pallet from the assembly jig  600  and place the empty assembly jig  600  on the second conveyor system  206  for return to the boring machine  100 .  
       Conclusion  
       [0054]    While various embodiments of the present invention have been described above, it should be understood that they have been presented by the way of example only, and not limitation. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.

Technology Category: 4