Abstract:
A fastener for a fitness equipment superstructure includes a stud member and a peg member, both of which include a head and a body. The body is sized to be received in holes on uprights of the superstructure to attach one or more accessories thereto. The head is significantly larger in diameter than the body, but thin with a circular profile and radiused corner. The stud member includes a thread portion which mates into a threaded recess in the body of the peg member, with the heads opposing each other on opposite sides of the upright.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    The present application claims priority from Provisional Application No. 61/844,075, filed Jul. 9, 2013 and entitled “Fastener For Fitness Apparatus”. The contents of U.S. provisional patent application Ser. No. 61/844,075 are hereby incorporated by reference in entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to bolts and similar threaded fasteners, particularly for use in assembled fitness equipment superstructures. Fitness equipment superstructures, also referred to as “rack and rig” systems, are known in the art. These systems are mainly for and used in cross fit gyms, pull up rigs, and other athletic/exercise facilities. 
         [0003]    The fitness equipment superstructures normally include several uprights or columns. Generally speaking, each upright is constructed from a steel (or other strong metal) tube, such as a 2×2, 2×3 or 3×3 inch rectangular tube, with a number of holes formed along its length. These tubes typically have about an 8 or 9 foot length, with the tube welded at one of its ends to a flat base plate. The flat base plate typically includes bolt holes for bolting to the floor. The holes along the length of the upright are for attaching cross-member bars running between the uprights, or for attaching J-cups and other accessories and hardware. 
         [0004]    Common bolts and nuts are used as fasteners for the uprights or J-cups or other accessories, with the bolt running through the rectangular tube. The holes in the uprights are typically fairly large, such as about an inch in diameter. Standard one inch diameter bolts have a hexagonal head which is within the range of 0.5-0.7 inches long, with a distance between opposing flats of about 1½ inches. The length of the bolts (extending from and not including the head) is typically 2½ to 4 inches, to match with the size of the rectangular tube with sufficient threads extending through the tube for attachment of a nut on the other end. The nut used on the opposing end of the bolt is typically a hexagonal nut sized similarly to the bolt head, such as with a length within the range of 0.5-0.8 inches and a distance between opposing flats of about 1½ inches. Such sizes of standard bolts and nuts are useful to support the strains and stresses which will be placed on the rack, such as holding hundreds of pounds of weights or other exercise equipment or withstanding the weight/momentum of an athlete during training. 
         [0005]    In years of use in fitness equipment superstructures, the nuts and bolts which are widely used have several drawbacks, which are often not appreciated by users until it is too late (and, to Applicant&#39;s knowledge, have not been previously appreciated by fitness equipment superstructure designers). While standard bolts of this size have fairly coarse threads (such as 8 threads per inch of length), the forces placed on the threads during use, and particular impact forces on the threads, can cause the threads to deform. Deformed threads can make it impossible to fully tighten a nut, or if the deformation exists on the end of the threads while the nut is further tightened on, can make it impossible to remove the nut. The corners of the bolt heads and nuts, extending a significant distance away from the upright, can cause injury to the athlete during inadvertent contact. The coarse threads of the bolt can also cause injury to the athlete during any inadvertent contact. Better solutions for attaching cross-member bars, J-cups and other accessories and hardware to the uprights of fitness equipment superstructures are needed. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention is a fastener for a fitness equipment superstructure, and a fitness equipment superstructure which uses the fastener such as in attaching one or more accessories to uprights of the superstructure. The fastener includes a stud member and a peg member, both of which include a head and a body. The body is sized to be received in holes on the uprights of the superstructure. The head is significantly larger in diameter but thinner, so as to fit closely to the upright without having any sharp corners. The stud member includes a thread portion which mates into a threaded recess in the body of the peg member, with the heads opposing each other on opposite sides of the upright. The fastener is less likely to be damaged than prior art bolts/nuts, avoids safety issues created by prior art bolt/nuts, and provides a more robust attachment than prior art bolts/nuts. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a fitness equipment superstructure in accordance with the present invention. 
           [0008]      FIG. 2  is a perspective view of one of the fasteners of the fitness equipment superstructure of  FIG. 1  in a detached state. 
           [0009]      FIG. 3  is a side view of the fastener of  FIG. 2  in a fully tightened state. 
           [0010]      FIG. 4  is a cross-sectional side view of the fastener of  FIGS. 2 and 3  shown tightened to hold an accessory to one of the uprights as depicted in  FIG. 1 . 
       
    
    
       [0011]    While the above-identified drawing figures set forth a preferred embodiment, other embodiments of the present invention are also contemplated, some of which are noted in the discussion. In all cases, this disclosure presents the illustrated embodiments of the present invention by way of representation and not limitation. Numerous other minor modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention. 
       DETAILED DESCRIPTION 
       [0012]    As shown in  FIG. 1 , a fitness equipment superstructure  10  has, in this example, four columns or uprights  12 . In this preferred embodiment, each of the uprights  12  is formed from a 3×3 inch metal tube. The preferred metal tubes are about 8 or 9 feet long, formed from rectangular steel tubing with a wall thickness of about 0.13 inches. Each upright  12  has a series of holes  14  running along its height, which can be used to fasten supports and accessories to the uprights  12 . The preferred holes  14  are about 1.06 inches in diameter, spaced at about 2 inch and about 6 inch intervals as desired for mounting hardware to the fitness equipment superstructure  10 . If desired, numbering or lettering or a ruler-type scale can be placed on the uprights  12  so users can more readily determine which hole  14  is which and find it easier to return the superstructure  10  to a particular configuration. 
         [0013]    In this example, the uprights  12  are attached together at their tops with two rectangular cross-bars  16  running from front to back, as well as three smaller circular cross-bars  18  running from side to side, two in front and one in back. The circular cross-bars  18  can be used, for instance, for pull-ups or similar exercises. The bases of the uprights  12  are secured together with floor beams  20 . One of the rear uprights  12  is shown with a series of four weight pegs  22  attached. The weight pegs  22  can be used to hold weightlifting plate freeweights (not shown) as known in the art. Bench or seat supports  24  are attached extending forward from each of the front uprights  12 . J-cups  26 , which can be used to support a weightlifting bar (not shown), are attached facing forward from each of the front uprights  12 . It can readily be understood that a wide variety of different configurations of fitness equipment superstructure set-ups can be achieved with these and similar uprights and accessories, including many configurations which use more than four uprights. 
         [0014]    In this preferred embodiment, each of the attachments to the uprights  12  are achieved with one or more fasteners  28 , with the preferred fastener  28  shown in more detail in  FIGS. 2-4 . Each of the accessories  16 ,  18 ,  22 ,  26  includes a plate  30  which is pressed against and attached to the uprights  12  with at least one fastener  28 . The fastener  28  includes a female threaded peg member  32  which mates with a male threaded stud member  34 . 
         [0015]    Both the peg member  32  and the stud member  34  have a head  36  projecting from a body  38 . In the preferred embodiment, the head  36  of the peg member  32  is shaped identically to the head  36  of the stud member  34 . The head  36  provides a flat shoulder  40  which needs to have enough surface area to transfer the tensile force of the fastener  28  into compression on the sidewalls of the upright  12 . The surface area of the flat shoulder  40  in contact with the sidewalls of the upright  12  preferably exceeds the area of the holes  14 . In the preferred embodiment for use with 1.06 diameter inch holes  14  in the uprights  12 , the head  36  has an outer diameter of 1.88 inches, providing nearly 1.9 square inches of surface contact between the shoulder  40  and the sidewalls of the uprights  12 . At the same time, the shoulder  40  should be small enough that the head  36  is well spaced inwardly from the edges of the upright  12 . With a 3×3 upright  12 , the head  36  has clearance on each side of about a half an inch from the edges of the upright  12 . The same head  36  can be used with 2×3 and 2×2 uprights, but within minimal clearance on each side when used on an upright that is only 2 inches wide. The head  36  needs to be thick enough to withstand the tightening force without bending, but otherwise is preferably as thin as possible. This will typically require the head  36  to be at least as thick as the walls of the tubing of the uprights  12 , but about equal to or less than twice as thick as the walls of the tubing of the uprights  12 . In the preferred embodiment, the head  36  is about 0.25 inches thick, which is 50% or less of the thickness of the head of traditional bolts/nuts the fastener  28  replaces. The head  36  should provide as few sharp corners as possible. In the preferred embodiment, this is achieved by having the head  36  be circular, with a generously radiused corner  42  (such as a radius of half of the thickness of the head  36 ). 
         [0016]    By being thin, without any sharp corners, there is significantly less chance that the head  36  will snag on the user&#39;s body or clothes, and significantly less chance of the head  36  causing inadvertent contact or injury with the user while exercising. The surface area of the head  36  provides a location to print promotional information, such as the name of the manufacturer into the head  36  in text with about 0.06 inch depth embossed therein. 
         [0017]    With the head  36  not having the flats of the traditional bolt/nut, a mechanism is needed to rotationally torque the stud member  34  and the peg member  32 . In the preferred embodiment, this is provided by an allen wrench recess  44 , with the preferred recess  44  being 0.45 inches deep and mating with a 0.5 inch hex drive (not shown). The stud member  34  has a thread portion  46  which extends for a threaded distance long enough to join with the peg member  32  with several turns of interlocking thread, both when used on an upright  12  by itself (i.e., when the shoulders  40  are 3 inches apart, such as when securing something inside the upright  12 ) and when used in attaching a plate  30  to an upright  12 . The shoulder  40  of the peg member  32  is thus spaced from the shoulder  40  of the stud member  34  by a distance of two (when sized for 2×2 or 2×3 inch uprights  12 ) to four inches. The preferred thread portion  46  is 1 inch long and ½ inch in diameter, threaded with size 13 UNC threads. The ½ inch diameter of the thread portion  46  and the size 13 UNC threads have been found sufficient to withstand the tensile forces placed on the fastener  28  during normal use. Preferably a non-permanent thread locker compound (not shown) is applied over about half of the length of the thread portion  46 . 
         [0018]    The thread portion  46  projects from a body  38 . The body  38  needs to be small enough to be received in the holes  14  of the upright  12 . The body  38  extends with a length that exceeds twice the wall thickness of the tubes of the uprights  12 . In the preferred embodiment, the body  38  extends for about 0.45 inches, and is cylindrical with an outer diameter of 1 inch. The body  38  fulfills several functions. First, the body  38  receives the alien wrench recess  44  and has sufficient thickness beyond the alien wrench recess  44  to transfer torque from the head  36  to the thread portion  46 . Second, the body  38  mates a significant distance into the hole  14  which receives it, to withstand shear forces of whatever it is attaching to the upright  12 . This is best seen in  FIG. 4 , wherein the body  38  extends both through the accessory plate  30  and fully into the hole  14  in the upright  12 . In this way, the shear forces between the accessory plate  30  and the upright  12  are withstood by the body  38  rather than by the thread portion  46 , meaning that the thread portion  46  is much less likely to be damaged during use than the prior art bolt (such as when the user drops a weight bar onto the J-cups  26 ). 
         [0019]    The peg member  32  also has a body  38  which in the preferred embodiment is cylindrical. The preferred body  38  of the peg member  32  extends for about 2½ inches beyond the shoulder  40 , meaning that if fully tightened the two bodies  38  abut each other when the shoulders  40  are about 2.95 inches apart, which permits full tightening onto the 3×3 inch upright  12 . Whenever attaching an accessory plate  30  to the outside of the upright  12 , the bodies  38  will be spaced apart by at least the thickness of the accessory plate  30 . The body  38  of the peg member  32  includes a female threaded recess  48  which mates with the thread portion  46  of the stud member  34 . In the preferred embodiment, the female threaded recess  48  is about 1.25 inches deep, with ½ inch diameter size 13 UNC threads (0.42 inch inner diameter). 
         [0020]    Both the peg member  32  and the stud member  34  are formed of a strong metal. In the preferred embodiment, both are formed of ASTM A325 steel, with at least a 120 KSI tensile strength and a 92 KSI yield strength. A finish may be applied, such as of polished black zinc. 
         [0021]    The fasteners  28  of the present invention provide attachments that are more robust and less likely to damage or strip than prior art bolts and nuts. The fitness equipment superstructure  10  using the fasteners  28  provides more safety to users, while at the same time offering a cleaner looking appearance. 
         [0022]    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.