Abstract:
A rail system of a plurality of rail units is disclosed with a fast, easy-to-use and secure fastening apparatus. The rail system is scalable from toy applications to heavy duty industrial applications by changing the sizes and the materials comprising the components of the system. The fastening apparatus provides high holding forces relative to the ease of snapping to create or release a connection between objects.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 13/717,159 filed on Dec. 17, 2012, now U.S. Pat. No. 9,032,593, which is a continuation-in-part of U.S. patent application Ser. No. 12/783,258 filed on May 19, 2010, now U.S. Pat. No. 8,341,810, which claims the benefit of U.S. Provisional Application No. 61/248,561 filed on Oct. 5, 2009, all of which are hereby incorporated by reference in their entireties. 
     
    
     BACKGROUND 
       [0002]    Modular rail systems have many applications, from heavy duty industrial applications such as construction to light duty applications such as building toys for creating various constructs limited only by the imagination of a child. 
         [0003]    How the rail units connect with one another, how quickly they fasten and unfasten, and how securely they fasten to one another distinguish light duty from heavy duty modular rail systems. It may be desirable to have a fastening apparatus for a modular rail system that can be scaled up or scaled down, depending upon the application. A modular rail system with an improved fastening apparatus may minimize the number of parts and the time required for connecting rail units. Such a modular rail system may permit fast, snap-action releasable connections that are reliable and secure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Features and advantages may become more apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings, described in brief below. 
           [0005]      FIG. 1  is an exemplary rail system having an end-to-end connection. 
           [0006]      FIG. 2  is an exemplary rail system having a locking collar over an end-to-end connection. 
           [0007]      FIG. 3  is an exemplary rail system having and end-to-side connection. 
           [0008]      FIG. 4  is an exemplary rail system having and end-to-side connection. 
           [0009]      FIG. 5  is an exemplary rail system having and end-to-side connection. 
           [0010]      FIG. 6  is an exemplary rail system having and end-to-side connection. 
           [0011]      FIG. 7A  shows a cross-section of an exemplary resilient element for use with rail systems. 
           [0012]      FIG. 7B  shows a cross-section of an exemplary resilient element for use with rail systems. 
           [0013]      FIG. 7C  shows a cross-section of an exemplary resilient element for use with rail systems. 
           [0014]      FIG. 7D  shows a cross-section of an exemplary resilient element for use with rail systems. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Exemplary, non-limiting embodiments of rail systems and rail units are disclosed herein, as are associated methods. 
         [0016]      FIG. 1  shows an exemplary rail system  500  having at least rail unit  502 , which is removably engagable with a rail unit  504 . “Rail” units, as used herein, may have any of a number of shapes, non-limiting examples of which are illustrated in  FIGS. 1-6 . Typical general shapes may include substantially cylindrical rails or substantially rectangular prism rails. Rails may be hollow or solid, or include internal structures such as ribs and channels of various shapes and sizes. 
         [0017]    Rail units may be made from any of a number of rigid materials. Stronger materials may be used in heavier duty applications, while softer or less expensive materials may be used in lighter duty applications. Exemplary materials may include but are not limited to metals, composite materials, and plastics, optionally with additives. Metals may include any of a number of steel alloys, aluminum alloys, including anodized aluminum. Composite materials may include polymer-based substrates in matrices with resin(s). Plastics may include thermoplastics and thermosetting plastics. Additives may include reinforcing additives such as, by way of non limiting examples, ceramics such as glass fibers, carbon fibers, biofibers, aramid fibers, nano particles, and others. Other additives are contemplated, and may include fillers, impact modifiers, anti-tack agents. Rail units may be made or formed by any of a number of manufacturing processes, including extrusion, injection molding, stamping, roll-forming, investment casting, and other methods. Coatings may optionally be applied to one or more surfaces of a rail unit. Coatings may include protective coatings, wear-resistance coatings, coatings to reduce or increase a coefficient of friction, anti-corrosive coatings, water-resistant coatings, UV-resistant coatings, platings, conductive coatings, and insulative coatings. 
         [0018]    In  FIG. 1 , a rail unit  502  is shown with a fastening apparatus  510  having a cam portion  514   a  and a hook portion  514   b.  Fastening apparatus  510  can be integral with rail unit  502 , or fastened to rail unit  502  with adhesives and/or mechanical fasteners  555 . Thus, a body of fastening apparatus  510  can be of the same or different materials than the rail unit  502 . In some exemplary embodiments, the body of fastening apparatus  510  can be formed together with rail unit  502 . 
         [0019]    The exemplified cam portion  514   a  includes a detent  548  and a recessed or convex portion  550 . The exemplified hook portion  514   b  includes resilient element  538 , which resides at least partially in a recess, cavity or channel. The channel is flanked by protrusions  540  and  541 , and an opening exists between the protrusions  540  and  541  for access to the resilient element  538 . The shapes of protrusions  540  and  541  define the size of the opening and ease of access for incoming structure to compress resilient element  538 . 
         [0020]    Rail unit  504  has structural sections that releasably engage with the fastening apparatus  510 . In the depicted exemplary embodiment, the structural sections are first and second flanges  520 . The rail units  502  and  504  are releasably engageable when a first flange  520  is pushed against resilient element  538  to compress same, and a second flange  520  is then snapped into convex portion  550 . 
         [0021]    Resilient element  538  has properties that are spring-like, but advantageously, it does not include moving parts as does, for example, a traditional coil spring. Rather, without being bound by theory, resilient element  538  operates in the rail system  500  generally according to hydraulics principles. Rail units  502  and  504  remain rigid—they do not bend during acts of securing or releasing—while the resilient element  538  is compressed and decompresses. The resilient element  538  is made from materials having resiliency properties. Thus, when compressed, resilient element  538  is bias toward adopting its original shape. After the snap action securement of the second flange  520  into position, previously compressed resilient element decompresses to return toward its original shape. More stiff resilient elements may be used where a more secure fit is required and significant force is required snap rail units together and take them apart. Less stiff resilient elements may be used where less force is required for such actions. 
         [0022]    The resilient element  538  may be made from any number of resilient materials, including but not limited to any of various polymers or natural or synthetic rubbers including silicone rubber or polyurethane. Shape-memory metal alloys and shape-memory polymers may also be suited for use in the composition of resilient element  538 . Resilient element  538  may be strips, cord, or rods. Strips, cords and rods, of course, are not limited to particular shapes or dimensions. For example, referring to  FIG. 7 , a variety of shapes of exemplary resilient elements  538  are shown by cross-section. 
         [0023]      FIG. 2  shows an exemplary end-to-end connection between two rail units  602  and  604 , reinforced with support sleeve  606 . In the example of  FIG. 2 , the rail units  602  and  604  are substantially cylindrical in shape, and support sleeve  606  is a hollow tube with in inner diameter just large enough to slide over an outer diameter of the rail units  602  and  604 , and then be secured in place by any a number of mechanisms including but not limited to pins, screws, bolts or other structures through one or more apertures  655  with receiving structure in or on the rail units  602  and  604 . Support sleeve  606  can provide mechanical strength to minimize bending of connected rail units  602  and  604  at or near the joint where fastening apparatus  610  is engaged with flanges  620 . Support sleeve  606  may also provide stabilization between rail units. Support sleeves  606  can be used with cylindrical rail units or with rail units of other general shapes such as rectangular prisms, so long as its shape is complementary to the rail unit. 
         [0024]      FIG. 3  shows an exemplary rail system  700  with rail units  702  and  704  being connected in an end-to-side configuration via fastening apparatus  710 .  FIG. 4  shows an exemplary rail system  800  with rail units  802  and  804  being connected in an end-to-side configuration via fastening apparatus  810 .  FIG. 5  shows an exemplary rail system  900  with rail units  902  and  904  being connected in an end-to-side configuration via fastening apparatus  910 .  FIG. 6  shows an exemplary rail system  1000  with rail units  1002  and  1004  being connected in an end-to-side configuration via fastening apparatus  1010 . Generally, a rail unit has a surface with a hook portion and a cam portion, or a rail unit has a surface with structural sections for releasably engaging with hook portions and cam portions of other rail units. A rail unit may have one surface with a hook portion and a cam portion, and another surface with structural sections such as flanges for releasable engagement with other rail units. 
         [0025]      FIGS. 7A-7D  show cross-sections of exemplary resilient elements for use in the disclosed rail systems. The cross section illustrated in  FIG. 7A  is substantially circular, the cross section illustrated in  FIG. 7B  is a sector, or a circle with a “pie wedge” shape missing, the cross section illustrated in  FIG. 7C  is triangular, and the cross section illustrated in  FIG. 7D  is rectangular. Many shapes and sizes of resilient elements are contemplated for use with the fastening apparatus disclosed herein; the figures are merely illustrative. For example, a square cross section is contemplated, as are ovals. The use of a particular shape may permit tuning the amount of force needed for release or engagement in particular applications. 
         [0026]    Rail systems are not limited by numbers of rail units in a system or whether particular connections are end-to-end, end-to-side, side-to-side or a combination of some or all such connections. Some rail units may be shaped to have only one connection point, others may be shaped to have several. Some rail units may have both a fastening apparatus on a surface of one end or side, and flanged portions on or in a surface of another end or side. The releasable connections made by the fastening apparatus are secure and reliable, and can be suitable for maintaining electrical connections in applications when securing one conductive surface against another. 
         [0027]    Applications for the disclosed rail systems are numerous. A collection of rail units could, for example, make up a toy building system. Such a system may comprise a plurality of rail units of different sizes, shapes and colors being removably attachable with a series snap-action fastening apparatuses. When made from heavier duty materials, the disclosed rail system has larger scale applications. For example, the disclosed rail system is faster and easier to break down and put together than traditional assemblies requiring tools and mechanical fasteners like nuts, bolts, screws and the like. With the snap-action fastening apparatus of the disclosed rail system, few if any tools and mechanical fasters may be necessary in the set up or break down. On still a larger scale, a rail system that supports construction elements like drywall and windows for commercial buildings. 
         [0028]    Regardless of scale, the snap-action fastening apparatus (examples of which are illustrated as  510 ,  610 ,  710 ,  810 ,  910  and  1010 ), provides a high holding force relative to the ease of snapping to create or release a connection with the apparatus. The high holding force is such that there is little or discernible movement or slop between connected objects. Also advantageously, objects connected with the snap-action fastening apparatus do not compare apart accidentally or via random external forces. Intentional application of force to snap on or snap off is the way to create and release the connections. 
         [0029]    While the rail systems and fastening apparatuses have been described in reference to some exemplary embodiments, these embodiments are not limiting and are not necessarily exclusive of each other, and it is contemplated that particular features of various embodiments may be omitted or combined for use with features of other embodiments while remaining within the scope of the invention. The apparatuses may be scaled up or down for use in applications not expressly disclosed or referenced herein, and the materials may be selected for certain properties such as conductivity, insulative properties, rigidity and the like.