Abstract:
A connecting pin includes a head and a body having a first end connected to the head. The body includes an underside having at least one surface arranged on a first plane parallel to a longitudinal direction. The body also includes a nose at a second end, the nose having an lower surface that extends upwardly and outwardly from the body underside. The body further includes an inclined surface extending to from an upper surface of the nose in the direction of the head.

Description:
[0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/999,910, filed Oct. 22, 2007. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to a device or pin for coupling interlocked members. The invention has particular application in the construction of ready-to-assemble or quickly assembled structures, and particular items that incorporate interlocking members. 
         [0003]    Ready-to-assemble structures are easy to construct, often without tools. Structures of this type are often favored because they are relatively inexpensive to make and purchase and therefore provide a low-cost alternative to other more involved constructions. Ready-to-assemble (or RTA) structures have been developed that are durable and strong enough to survive a significant time under normal use. Another benefit of RTA structures is that they can often be disassembled for transport and then re-constructed at a new location. 
         [0004]    One common application of RTA technology is as furniture or shelving, such as the shelf unit shown in  FIG. 1 . RTA furniture is especially useful in children&#39;s rooms or college dormitories because it is inexpensive yet durable. Another use of RTA technology has been in the construction of lower cost caskets. One such casket is disclosed in pending application Ser. No. 10/898,552, entitled “Mortise and Tenon Casket” and published as U.S. 2005/0138782 on Jun. 30, 2005, the disclosure of which is incorporated herein by reference. This application discloses a low cost casket that retains much of the strength and beauty of more expensive natural wood caskets. In one embodiment disclosed in the 3 552 Application, a mortise and tenon joint construction is used to interlock components of the casket. This joint construction employs a tab extending from one component, such as a bottom panel, that projects through a slot formed in another component, such as a side panel of the casket. The tab defines a hole through which a pin is inserted to fix or interlock the tab to the side panel. An example of this mortise and tenon casket is shown in  FIG. 8 . 
         [0005]    This mortise and tenon joint construction is particularly useful for RTA structures because the resulting joint is very firm and stable. This joint construction is also easy to implement in a wide range of materials, such as wood, plastic or metal since the machining required for the interlocked components involves forming a hole in one component and a slot in another. 
       SUMMARY OF INVENTIVE FEATURES 
       [0006]    The present invention thus provides several exemplary inventive features which are included in various embodiments thereof. In particular, at least some embodiments of the present invention contemplate a molded pin for use in a mortise and tenon or similar interlocking joint construction. In one embodiment, the molded pin is adapted to be substantially permanently interlocked within the joint to lock two members together. In this embodiment, the pin includes an integral locking barb that extends from a planar lower surface of the pin and that is adapted to be fixed within the joint. In a mortise and tenon joint construction, the locking barb is configured to engage within the slot of one member while the pin extends through a hole in the other member. 
         [0007]    A first embodiment is a connecting pin that includes a head and a body having a first end connected to the head. The body includes an underside having at least one surface arranged on a first plane parallel to a longitudinal direction. The body also includes a nose at a second end, the nose having an lower surface that extends upwardly and outwardly from the body underside. The body further includes an inclined surface extending to from an upper surface of the nose in the direction of the head. 
         [0008]    In a further exemplary feature of some embodiments of the invention, the molded pin includes a nose that defines curved or angled surfaces adapted to facilitate insertion of the pin into the joint. In another feature, these cured or angled surfaces may also be configured to exert pressure between the two members being interlocked, resulting in a very solid, substantially rigid interlocking connection. 
         [0009]    In another feature of some embodiments the invention, a molded pin is provided for temporary engagement within an interlocking joint, such as a mortise and tenon joint. In this feature, the temporary pin includes a head with features for manually gripping the pin to remove it from the joint. An indentation is defined in the pin adjacent the head that may be accessed by a prying tool, such as a common writing pen. The tip of the prying tool may be engaged within the indentation to pry the pin a sufficient amount to permit access to the manual gripping features on the head of the pin. 
         [0010]    In the illustrated embodiment, the pins  30  and  50  were shown interlocking a mortise and tenon joint in an article of shelving, with the pins locking horizontal shelf panels to vertical support panels. As described above, the pins  30  and  50  may also be used to lock the mortise and tenon joints of the low cost casket illustrated in  FIG. 8 . It is contemplated that the pins  30  and  50  of the present invention may be used to couple a wide range of members and with a wide range of interlocking joint constructions. Thus while the pin  30  is especially well-suited for a mortise and tenon joint construction, as shown in  FIG. 3 , it may be adapted for use in other interlocking joints. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows perspective view of an exemplary a shelf unit that implements an embodiment of the present invention; 
           [0012]      FIG. 2  shows a side cutaway view of a portion of the shelf unit of  FIG. 1  showing a first mortise and tenon connection arrangement; 
           [0013]      FIG. 3  shows a side fragmentary cutaway view of the first mortise and tenon connection of  FIG. 2  and which employs a first embodiment of a connecting pin in accordance with the invention; 
           [0014]      FIGS. 4(   a )- 4 ( i ) show multiple views of the first embodiment of the connecting pin of  FIG. 3   
           [0015]      FIG. 5  shows a side cutaway view of a portion of the shelf unit of  FIG. 1  showing a second mortise and tenon connection arrangement; 
           [0016]      FIG. 6  shows a side fragmentary cutaway view of the second mortise and tenon connection of  FIG. 5  and which employs a second embodiment of a connecting pin in accordance with the invention; 
           [0017]      FIGS. 7(   a )- 7 ( e ) show multiple views of the second embodiment of the connecting pin of  FIG. 6 . 
           [0018]      FIG. 8  shows an exemplary embodiment of a casket that employs mortise and tenon connection arrangements in accordance with one or more embodiments of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    The present invention concerns a molded pin for use in mortise and tenon joint constructions. In one embodiment the pin is constructed as a permanent, non-removable pin, while in another the pin is temporary and removable. The molded pin may suitably have uses in constructions other than mortise and tenon constructions. 
         [0020]      FIG. 1  shows a first environment in which molded pins in accordance with the present invention may be employed. As depicted in  FIG. 1 , a shelf unit  10  may include a series of shelf panels  12  supported by at least two vertical panels  14 . A joint  16  is formed between each shelf panel and each vertical panel to hold the assembly together. As shown in the detail view of  FIG. 3 , this joint is a mortise and tenon joint construction. The vertical panel  14  defines a slot  20  that receives a tab  22  extending from an edge of the shelf panel. The tab  22  defines an opening  24 . As depicted in  FIG. 3 , the opening  24  is oriented so that a portion of the opening is outside the slot  20  while another portion is situated within the slot. 
         [0021]    In accordance with the disclosed embodiment, a pin  30  extends through the opening  24  in the tab  22 . The pin has a length sufficient to span the width of the slot  20  in the side panel so that it bears directly on the side panel  14  on either side of the tab  22 . The pin  30  includes an enlarged head  34  at one end that prevents the pin from passing completely through the opening  24 . 
         [0022]    Details of the pin  30  are best seen in  FIGS. 4(   a )- 4 ( i ). In particular, the pin  30  is preferably a unitary body  31 , and most preferably a molded body. In a specific embodiment, the unitary body  30  is formed of a plastic material that is inexpensively and easily molded to include the features of the pin described herein. The body  31  defines the enlarged head  34  with a generally planar underside  35  that bears against the vertical panel  14 , as shown in  FIG. 3 . In one feature of the invention, the body  31  further defines a locking barb  32  that projects at an angle from the planar underside  35 . The locking barb  32  is particularly configured to extend into the slot  20 , as shown in  FIG. 3 , to lock the pin in place within the tab opening  24 . The locking barb  32  is preferably resiliently deformable so that the barb can pass through the space between the tab opening  24  and the outer face of the vertical panel. Once the pin  30  has been advanced far enough into the opening, the barb reaches the slot and engages the slot wall. 
         [0023]    In the illustrated embodiment, the locking barb  32  is in the form of an angled rib, as depicted in  FIGS. 4(   b ),  4 ( e ) and  4 ( g ). The rib is integrally molded with the body  31 . As shown in  FIGS. 4(   a )-( i ), the body  31  is molded to define a series of cavities to reduce the amount of material required to form the pin  30 , and to facilitate elastic deformation. Alternatively the body  31  may be molded as a solid body. 
         [0024]    The body  31  of the pin  30  includes a nose  38  opposite the head  34 . The nose is configured to facilitate passage of the pin into the hole  24  in tab  22  and to generate pressure on the locking barb as it locks in place within the slot  20 . Thus, in one embodiment, the nose  38  defines an angled or curved lower face  39  that angles upward from the underside  35  of the pin. This angled lower face  39  facilitates entry of the nose  38  into the exposed portion of the tab opening  24 . The nose  38  may also include a lateral angled face  41  ( FIG. 41(   d )) that helps guide the pin into the slot opening  24 . The upper face  40  of the nose  38  is also curved (i.e. angled with respect to the longitudinal plane) so that the nose assumes the general shape of a pry bar. Thus, as the pin  30  is advanced farther into the opening  24 , the upper face  40  contacts the tab  22  of the opening  24  (See  FIG. 3) . If the shelf  12  and panel  14  have some relative fit resiliency, further movement of the pin through the opening  24  essentially pries the tab  22  outward relative to outer surface  15  of the vertical panel  14 . 
         [0025]    As the pin is pushed through the tab opening, the lower face  39  contacts the vertical panel  14  at the opposite edge of the slot  20 . The angle or curvature of this lower face helps guide the nose  38  through the tab opening so that the lower face  39  bears against the outer surface  15  of the panel. At this point, the angled barb  32  also contacts the opposite edge of the slot  20  so that further advancement of the pin  30  through the opening  24  tends to pry the tab  22  even more. This prying action continues until the trailing edge  33  of the barb  32  reaches the slot  20 . The pin  30  is then locked within the opening  24  of the tab  22  with pressure primarily applied to the vertical panel  14  and shelf panel  12  at points P depicted in  FIG. 3 . 
         [0026]    It can thus be appreciated that the pin  30  provides a substantially permanent lock for the mortise and tenon joint between the panels  12  and  14 . The construction of the pin ensures a very tight lock as the curved or angled surfaces tend to pry apart the tab  22  from the outer surface  15  of the vertical panel  14 . The pressure points P maintain firm pressure on the pin to prevent the angled barb  32  from being dislodged from the slot  20  and tab opening  24 . All of this functionality may be advantageously provided by a molded plastic pin that is especially molded to reduce material. It can also be appreciated that forming the pin of plastic provide a low friction surface that makes facilitates manually driving the pin through opening into its locking engagement. 
         [0027]    In some cases, a permanent pin, such as pin  30 , is not required for assembly of an RTA structure. In another embodiment of the invention, a temporary pin  50  is also provided that may engage the same mortise and tenon joint construction described above. As shown in  FIG. 6 , the pin  50  includes a body  51  that is preferably molded in a plastic material like the pin  30 . The body  51  defines a planar underside  52  that extends along the entire length of the pin. Thus, unlike the pin  30 , the pin  50  does not include an interlocking feature like the angled barb  32 . 
         [0028]    The nose  53  of the body  51  may be angled or curved, as shown in  FIGS. 6 and 7(   d ) to facilitate insertion of the pin  50  into the tab opening  24 . The body  51  further defines an enlarged head  54  to act as a stop as the pin is inserted through the tab opening. As shown in  FIG. 6 , the head  54  is preferably hollow to reduce the material required for molding the pin. Moreover, as shown in  FIG. 7(   a ), the head  54  defines finger grips  55  on opposite sides of the head. These finger grips are contoured to receive the tips of a person&#39;s fingers so that the pin  50  may be grasped for removal. 
         [0029]    It can be appreciated that the pin  50  is preferably formed with a generally low profile, meaning that it does not extend too far beyond the tab slot  23 . Thus, the head  54  is also preferably configured for a low profile, which means that the finger grips  55  are positioned very close to the tab  22  when the pin  50  is fully inserted into the opening  24 , as illustrated in  FIG. 6 . In this position, the finger grips  55  are hard to manually engage. Thus, in one feature of the illustrated embodiment, the body  51  further defines a notch or indentation  58  at least partially formed in the head  54 . In particular, the indentation  58  is positioned so that at least a portion of the indentation is accessible even when the pin  50  is fully inserted into the tab hole. The indentation  58  is configured to receive the tip of a lever. In one embodiment, the lever may be a common writing pen, for instance, or some other common item adapted to be inserted into the indentation. The tip of the pen may be pressed into the indentation  58  and the pen used as a lever to dislodge the head  54  of the pin away from the tab  22 . Once the head has been moved sufficiently far from the tab  22 , the finger grips  55  are then available to be manually grasped. The pin  50  may then be pulled out of the opening  24 .