Abstract:
A two-piece pallet fastener for securing a pallet element to a base pallet is disclosed. The fastener includes a sleeve internal, male protrusions and a rivet having external, female threads. The sleeve is installed in a pallet base and the rivet is inserted through the part to be attached to the pallet base and into the sleeve. The sleeve includes a rivet-receiving end having an alignment feature and an anchoring end. The anchoring end includes flexible legs having external shoulders. The rivet includes a head and a shaft. The head includes an alignment feature. The shaft includes external, female threads and two or more axially-aligned longitudinal grooves. One or more detents are formed on the rivet for engagement with the interior surface of the sleeve. The detents are provided to produce a ratchet-type effect to assure that the rivet is locked into the sleeve.

Description:
TECHNICAL FIELD 
       [0001]    The disclosed inventive concept relates generally to fasteners for use in coupling two components together. More particularly, the disclosed inventive concept relates to a two-piece fastener for shipping pallets. The two-piece fastener includes a sleeve or nut having internal, male protrusions and a rivet or screw having external, female threads. Upon insertion of the rivet into the sleeve, the rivet is rotated, thereby pulling the rivet deeper into the sleeve. Upon full rotation, the male protrusions fit into detents formed within the rivet to prevent reverse rotation. The angular rotation provides clamp load once fully inserted and rotated. 
       BACKGROUND OF THE INVENTION 
       [0002]    Successful domestic and international trade relies on the efficient and cost-effective shipment of both finished and unfinished goods of different sizes in various quantities. Many of these articles, both unfinished and finished, must be moved on flat transport structures such as pallets or skids that can be readily moved by heavy machinery such as a forklift, a pallet jack or a crane. 
         [0003]    In order that shipping efficiency may be maximized at the lowest possible cost, the attachment of pallet components to one another must be undertaken quickly without compromising security or safety. Workers accordingly require a pallet fastening system that requires the least amount of effort to achieve complete fastening. 
         [0004]    Conventional pallet fastening methods typically rely on either adhesive fastening or on mechanical fasteners such as nails, conventional screws or lag bolts. Adhesive fastening relies on permanent adhesives such as wood glue. While being effective at adhesion, the use of permanent adhesives makes disassembly very difficult and often results in damage to the pallet components. 
         [0005]    Challenges faced by industries relying on mechanical fastening include different types of tools needed to install these fasteners. Nail fasteners result in cracked or damaged pallets. A further challenge is related to the disassembly of pallets once assembled, the challenge often including the removal of nails or the removal of threaded fasteners having stripped or damage fastener heads. Each of these challenges has the potential for increasing assembly cost to manufacturers because of added tooling as well as extra assembly and disassembly time. 
         [0006]    Modern demands on the design and construction of pallet fasteners mean that new pallet fastener solutions need to contribute to ease of assembly as used in production (particularly in view of increasing automation) and provide excellent attachment strength, while maintaining high reliability and low production costs. Compliance with the need for standardization and the requirements of the shipping industry has proved challenging to current pallet fastener designs. 
         [0007]    Accordingly, and as is the case in many industries, known pallet fasteners approaches to attaching pallet components together are often undesirable and impractical. An improved arrangement for attaching two pallet components together remains wanting. 
       SUMMARY OF THE INVENTION 
       [0008]    The disclosed inventive concept overcomes the problems associated with pallet fasteners by providing a simple and cost-effective response to the demands of the marketplace. Particularly, the pallet fastening system of the disclosed inventive concept includes a two-piece fastener that includes a sleeve or nut having internal, male protrusions and a rivet or screw having external, female threads. The sleeve is installed in a pallet base and the rivet is inserted through the part to be attached to the pallet base and into the sleeve. 
         [0009]    The sleeve may be made of any of several materials, though a polymerized material is preferred. The sleeve includes internal, staggered male protrusions. The sleeve includes a rivet-receiving end having an alignment feature and an anchoring end. The anchoring end includes flexible legs having external shoulders. 
         [0010]    The rivet may also be made of any of several materials, though a polymerized material is again preferred. The rivet includes a head and a shaft. The head includes an alignment feature. The shaft includes external, female threads and two or more axially-aligned longitudinal grooves. 
         [0011]    One or more detents are formed on the rivet for engagement with the interior surface of the sleeve. The detents are provided to produce a ratchet-type effect to assure that the rivet is locked into the sleeve. If two detents are provided, the first detent establishes a preload and the second detent establishes a maximum clamping load. The detents can include flat, rounded, curved and/or curvilinear surfaces. 
         [0012]    The base pallet includes a sleeve bore having a bored-out end for receiving the flexible legs of the sleeve. The pallet being attached to the base pallet includes a recess for receiving the rivet head. 
         [0013]    Upon insertion of the rivet into the sleeve, the rivet is rotated 90 degrees at an angle relative to the centerline of the length, thereby pulling the rivet deeper into the sleeve. Upon full rotation, the male protrusions fit into detents formed within the rivet to prevent reverse rotation. The angular rotation provides clamp load once fully inserted and rotated. 
         [0014]    The above advantages and other advantages and features will be readily apparent from the following detailed description of the preferred embodiments when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention wherein: 
           [0016]      FIG. 1  is a side view of a sleeve according to the disclosed inventive concept; 
           [0017]      FIG. 2  is an end view of the sleeve shown in  FIG. 1 ; 
           [0018]      FIG. 3  is a sectional view of the sleeve shown in  FIG. 1 ; 
           [0019]      FIG. 4  is a perspective view of the sleeve shown in  FIG. 1 ; 
           [0020]      FIG. 5  is a side view of a rivet for use with the sleeve shown in  FIG. 1  according to the disclosed inventive concept; 
           [0021]      FIG. 6  is a perspective view of the rivet shown in  FIG. 5 ; 
           [0022]      FIG. 7  is a sectional view showing the sleeve of  FIG. 1  shown in position attaching a first pallet to a second pallet with the rivet of  FIG. 5  locked therein; 
           [0023]      FIG. 8  is a detailed view of the head of the rivet in association with a portion of the first pallet locked into the sleeve according to the disclosed inventive concept; and 
           [0024]      FIG. 9  is a sectional view taken along line  9 - 9  of  FIG. 7  illustrating the rivet locked into the sleeve according to the disclosed inventive concept. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    As those of ordinary skill in the art will understand, various features of the embodiments illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce alternative embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations. 
         [0026]    The figures illustrate a system for fastening one object to another and, in particular, provides a system for attaching an upper object to a base pallet. The upper object may be a component needing to be stabilized on the base pallet or may be an upper pallet. While primarily intended for use with shipping pallets, the two-piece fastener system of the disclosed inventive concept may be used for virtually any other application in which a practical and easy-to-use approach to fastening two components together is needed. 
         [0027]    In general, the two-piece fastener system of the disclosed inventive concept includes a sleeve or nut that is fitted into the base pallet and a rivet or screw that is fitted through the component being attached to the base pallet and into the sleeve. The sleeve is illustrated in  FIGS. 1 through 4  and the rivet is illustrated in  FIGS. 5 and 6 . The two-piece fastener system is shown in use fastening an upper component to a base pallet in  FIGS. 7 through 9 . 
         [0028]    Referring to  FIGS. 1 through 4 , a sleeve, generally illustrated as  10 , is illustrated. It is to be understood that the illustrated configuration of the sleeve  10  is suggestive and is not intended as being limiting. Accordingly, and for example, the diameter and length of the sleeve  10  may be adapted as needed depending on the components being attached. The sleeve  10  may be composed of any of several materials including, for example and without limitation, a plastic. 
         [0029]    The sleeve  10  includes a sleeve body  12  having a rivet-receiving end  14  and a sleeve-insertion end  16 . The sleeve insertion end  16  includes a plurality of flexible locking legs  18 ,  18 ′,  18 ″ and  18 ′″. It is to be understood that while four flexible locking legs are illustrated, a greater or lesser number of flexible locking legs may be employed. The flexible locking legs  18 ,  18 ′,  18 ″ and  18 ′″ provide locking engagement with the base pallet as illustrated in  FIG. 6  and discussed below in relation thereto. 
         [0030]    Each of the flexible locking legs  18 ,  18 ′,  18 ″ and  18 ′″ includes a locking flange for engagement with the base pallet. Particularly, the flexible locking leg  18  includes a locking flange  20 , the flexible locking leg  18 ′ includes a locking flange  20 ′, the flexible locking leg  18 ″ includes a locking flange  20 ″, and the flexible locking leg  18 ′″ includes a locking flange  20 ′″. While each flexible locking leg is illustrated as having a single locking flange, a greater number of flanges could be provided having different configurations, such as having a single flange split into two halves. 
         [0031]    The sleeve  10  includes an axial bore that defines an interior wall  22 . Formed on the interior wall  22  is a plurality of staggered teeth  24 ,  26  and  28 . A greater or lesser number of teeth may be included. The teeth  24 ,  26  and  28  engage a like number of grooves formed on the rivet for engagement therewith. It is to be understood that while the teeth are illustrated as being formed on the interior wall  22  of the sleeve  10  and the grooves formed on the rivet, the grooves may be formed in the interior wall  22  and the teeth may be formed on the rivet. 
         [0032]    As illustrated in  FIG. 3 , the teeth  24 ,  26  and  28  are formed on the interior wall  22  in a staggered configuration along the length of the interior wall  22  such that tooth  24  is closest to the rivet-receiving end  14 , the tooth  28  is closest to the rivet-insertion end  16 , and the tooth  26  is positioned between the teeth  24  and  28 . This arrangement is preferred but not required as alternate arrangements may be adapted. Regardless of the configuration, the teeth  24 ,  26  and  28  are strategically located on the interior wall  22  so as to provide an effective interlock with the grooves formed in the rivet as discussed below. 
         [0033]    To assure a correct initial fit between the sleeve  10  and the rivet, an alignment feature  30  comprising a flat region is formed in the rivet-receiving end  14  of the body  12 . The alignment feature  30  makes it possible for the rivet to be correctly aligned to assure a proper connection as described below. 
         [0034]    The rivet, generally illustrated as  40 , is shown in  FIGS. 5 and 6  in which a side view and a perspective view of the rivet  40  are respectively set forth. It is to be understood that the illustrated configuration of the rivet  40  is suggestive and is not intended as being limiting. Accordingly, and for example, the diameter and length of the rivet  40  may be adapted as needed depending on the components being attached. The rivet  40  may be composed of any of several materials including, for example and without limitation, a plastic. 
         [0035]    The rivet  40  includes a shaft  42  having a depth-limiting cap  44  formed at one end and a rounded insertion end  47  for insertion into the rivet-receiving end  14  of the sleeve  10 . The depth-limiting cap  44  restricts the depth to which the shaft  42  may be inserted into the sleeve  10 . Formed on one side of the depth-limiting cap  44  is an alignment feature  46 . By aligning the alignment feature  46  of the cap  44  with the alignment feature  30  of the body  12  of the sleeve  10 , the installer can be certain that the teeth of the sleeve and the grooves of the rivet are correctly lined up prior to insertion. 
         [0036]    Externally formed along the long axis of the shaft  42  is a plurality of tooth receiving grooves to engage and interlock with the teeth  24 ,  26  and  28  formed on the interior wall  22  of the body  12  of the sleeve  10 . As noted in the description of the sleeve  10  the axially aligned grooves may be formed in the interior wall  22  of the body  12  while the teeth may be formed on the shaft  42  of the rivet  30 . 
         [0037]    Two of the three axially aligned grooves are illustrated in  FIG. 5 . These grooves include a long axial groove  48  and an intermediate axial groove  50 . The long axial groove  48  begins at the rounded insertion end  47  of the shaft  42  and ends relatively close to the cap  44  at an angled groove  52 . The angled groove  52  terminates at detent  54  that is generally aligned with the long axis of the shaft  42 . 
         [0038]    The intermediate axial groove  50  also begins at the rounded insertion end  47  of the shaft  42  and ends at an angled groove  56  at a point approximately mid-way between the rounded insertion end  47  and the cap  44 . As illustrated in  FIG. 6 , the angled groove  56  terminates at detent  58  that is generally aligned with the long axis of the shaft  42 . The detents  54 ,  58  and  64  may be flat, rounded, curved or curvilinear or a combination thereof. 
         [0039]    The third of the three axially aligned grooves is also illustrated in  FIG. 6  in which a short axial groove  60  is shown. The short axial groove  60  begins at the rounded insertion end  47  of the shaft  42  and ends at a point approximately mid-way between the detent  58  and the rounded insertion end  47 . The short axial groove  60  terminates at an angled groove  62  and the angled groove  62  terminates at detent  64 . The angled grooves  52 ,  56  and  62  are defined as sections of a helix and thus provide mechanical advantage in locking the rivet  40  relative to the sleeve  10  as set forth below. 
         [0040]    In use, the sleeve  10  is first inserted into the base pallet and the rivet  40  is then inserted through the part to be connected and into the sleeve  10 . This arrangement is illustrated in  FIGS. 7 through 9 . Referring to  FIG. 7 , a pallet assembly  70  is shown comprising a pallet base  72  and an upper component being attached to the pallet base  72 . 
         [0041]    As illustrated, the upper component is an upper pallet  74 . This being noted, it is to be understood that the two-piece fastener arrangement of the disclosed inventive concept may be used for a variety of pallet arrangements. Particularly the two-piece fastener arrangement is well-suited for use with a composite, high end shipping pallet intended for display, such as for medical and pharmaceutical purposes. For display purposes, it is necessary for the pallets to be aesthetically pleasing. It is also necessary for presentation purposes that the pallets be free of wood particles or other debris. Thus the pallets may be built from a combination of wood, high density foam, and one or more adhesives. Once prepared, the pallet is preferably coated with a compound available in various colors. After the pallet&#39;s useful life, it may be ground into reusable material. The two-piece fastener arrangement of the disclosed inventive concept is desired so that grinding equipment is not damaged as would be the case with conventional mechanical fasteners, such as metal fasteners. Serviceability of the pallet is also a requirement, which the disclosed inventive concept provides. 
         [0042]    Sectional views of the rivet  40  inserted into and connected with the sleeve  10  in  FIGS. 7 and 8 . Particularly, a bore comprising a lower bore portion  76  having a locking flange receptacle  78  bored out at its lowermost end and an upper bore portion  80 . A countersunk bore  82  is formed in the upper pallet  74  into which is fitted the depth-limiting cap  44  once the rivet  40  is fully inserted into the sleeve  10 . 
         [0043]    Attachment of the upper pallet  74  (or upper component) to the pallet base  72  according to the disclosed inventive concept is achieved according to the following steps. Initially, the upper pallet  74  is moved over the pallet base  72  to its desired position. Thereafter, the lower bore portion  76 , the locking flange receptacle  78 , the upper bore portion  80  and the countersunk bore  82  are formed in the upper pallet  74  and the pallet base  72 . Alternatively, the lower bore portion  76 , the locking flange receptacle  78  and the upper bore portion  80  may be formed prior to assembly of the upper pallet  74  and the pallet base  72 . 
         [0044]    The sleeve  10  is then inserted into the upper bore portion  80 . Because of their flexibility, upon insertion into the upper bore portion  80 , the flexible locking legs  18 ,  18 ′,  18 ″ and  18 ′″ flex slightly toward the center of the body  12  of the sleeve  10 . Insertion of the sleeve  10  continues until the locking flanges  20 ,  20 ′,  20 ″ and  20 ′″ engage the locking flange receptacle  78  as illustrated in  FIG. 7 . The locking of the locking flanges  20 ,  20 ′,  20 ″ and  20 ′″ in this manner prevent movement of the sleeve  10  from the pallet base  72 . The locked placement of the sleeve  10  is further secured upon insertion of the rivet  40  therein by which the rounded insertion end  47  of the rivet  40  prevents the flexible locking legs  18 ,  18 ′,  18 ″ and  18 ′″ from being flexed inward as shown in  FIG. 7 . 
         [0045]    With the sleeve  10  in its fully inserted position, the rivet  40  is then positioned over the rivet-receiving end  14  of the sleeve  10 . As noted, the alignment feature  46  formed on the cap  44  of the rivet  40  is used to align the rivet  40  with the alignment feature  30  formed in the body  12  of the sleeve  10 . Once proper alignment of the rivet  40  with respect to the sleeve  10 , the rounded insertion end  47  of the rivet  40  is inserted into the rivet-receiving end  14  of the sleeve  10 . To aid in the insertion of the rivet  40  into the sleeve  10 , the cap  44  preferably includes a tool insertion cavity  84 . The insertion cavity  84  may be of virtually any suitable configuration, including a slot to receive a screwdriver, a hex to receive a socket wrench, or a Torx® opening to receive a suitable driver. Proper alignment of the rivet  40  with respect to the sleeve  10  assures that the tooth  24  is slotted first into the long axial groove  48 . 
         [0046]    Continued insertion of the rivet  40  into the sleeve  10  results in the tooth  26  being slotted into the intermediate axial groove  50 , while complete insertion of the rivet  40  into the sleeve  10  results in the tooth  28  being slotted into the short axial groove  60 . 
         [0047]    Insertion of the rivet  40  into the sleeve  10  continues until the cap  44  halts linear movement of the rivet  40  resulting in the initial setting of the teeth  24 ,  26  and  28  in their respective grooves  48 ,  50  and  60 . A sectional view taken along line  9 - 9  of  FIG. 7  illustrates the initial setting of the teeth  24 ,  26  and  28  relative to the grooves  48 ,  50  and  60  respectively. 
         [0048]    Once fully inserted, the installer rotates the rivet  10 , for example, by ninety degrees, whereby the tooth  24  engages the angled groove  52 , the tooth  26  engages the angled groove  56 , and the tooth  28  engages the angled groove  62 . Because the grooves  52 ,  56  and  62  are at an angle relative to the long axis of the shaft  42  of the rivet  10 , continued rotation draws the rivet  10  into the sleeve  40 . 
         [0049]    Final rotation of the rivet  40  in the sleeve  10  results in the tooth  24  engaging the detent  54 , the tooth  26  engaging the detent  58 , and the tooth  28  engaging the detent  64 , thereby locking the rivet  40  in place within the sleeve  10 . The detents  54 ,  58  and  64  operate in combination to produce a ratchet-type effect. In this locked position, reverse rotation of the rivet  40  relative to the sleeve  10  is prevented. 
         [0050]    One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.