Abstract:
An adjustable connector that can slide along a rod or tube and can be secured from axially translating in infinite positions along the entire length of the tube. It also has the capability of attaching itself to a surface or structural element such as a shelf.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     The invention is in the field of joints and connections. A particular need arose for the construction of inexpensive and easily constructed shelving. Shelving schemes that I am aware of are of the box variety with sides and backs, those that use special standards with incremental spacing that have to be attached to a wall and those with frames that are assembled with nuts and bolts. The inventor felt the need for something different and so conceived of this particular article. Many devices, some quite old (U.S. Pat. No. 2,187,880 to Kaysing 1938),(U.S. Pat. No. 4,159,134 to Shemtov 1979)and (U.S. Pat. No. 4,508,466 to Dennis 1985) have used the coupling shown in some embodiments of this invention but none to my knowledge have used it in this unique way. 
     BRIEF SUMMARY OF THE INVENTION 
     The primary objective of the current invention is to provide the means to create an adjustable support system that can utilize inexpensive, thin wall electrical tubing. The essence of the invention is a two or three-piece coupling that consists of a hollow cylindrical body, gland nut and split clamping ring or split clamping collar. 
     It can slide along the tube and be locked at any point without marking or piercing the tube. The connector has the capability, as well, to attach to another element such as a shelf. It&#39;s application though, is not at all limited to shelving but can be used create other types of structures. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 shows an exploded view of the first coupling. 
     FIG. 2 shows a sectional view of the first coupling. 
     FIG. 3 shows a typical mounting hole in a generic surface. 
     FIG. 4 shows an exploded view of the second coupling. 
     FIG. 5 shows a sectional view of the second coupling where only the mounting surface is cut away. 
     FIG. 6 shows an isometric view of the third coupling. 
     FIG. 7 shows a typical use of any coupling. 
    
    
     REFERENCE NUMERALS IN DRAWINGS 
       10  general designation of the first coupling 
       12  split annular locking ring 
       14  gland nut of the first coupling 
       16  rod or tube 
       18  typical mounting surface 
       20  barrel with machine thread 
       22  wood thread 
       24  mounting body of first coupling 
       26  chamfered edge on bore 
       28  interior space of the gland nut 
       30  split in clamping ring 
       32  general designation of the second coupling 
       34  holes for fasteners 
       36  gland nut of the second coupling 
       38  shoulder for centering 
       40  recess for spanner wrench 
       42  fasteners 
       44  bore 
       46  starting chamfer 
       48  radially extending flange of the first coupling 
       50  radially extending flange of the second coupling 
       52  typical hole in mounting surface 
       54  radially split clamping collar of the third coupling 
       56  split clamping collar cap screw 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings that illustrate the first, second and third couplings, the only essential difference between them being the way in which they attach to the mounting surface and/or clamp to the rod or tube. The reference numeral  10  designates the ensemble of the first coupling (FIGS.  1  and  2 ). This consists of a gland nut  14  similar to a packing gland. This nut has a inwardly facing peripheral flange with a sloping inside face that creates a relieved interior  28  to contain split annular locking ring  12 , it also has six flat surfaces on the outside, enabling it to be tightened with a conventional wrench. Locking ring  12  is C shaped in cross section and split  30  to allow for expansion and contraction, the edges of the ring are sharp the better to grip the rod. Mounting body  24  is a hollow cylinder with a radially extending flange  48  about midway up the cylinder, it has a bore  44  of constant diameter that extends the entire length of the cylinder. This bore is of sufficient diameter to allow rod  16  to loosely pass completely thru. One end  20 , a threaded barrel, of body  24  has machine threads to engage nut  14 , the same end has a small circumferential chamfer  26  at the edge of the bore that opposes the sloped area of  14  to force the locking ring towards the rod when the nut is tightened and the annular space is compressed thus gripping the rod firmly. The other end having a wood engaging thread  22 , of body  24  is constructed in such a way as to make it easy to thread into wood. This is accomplished by making the threads fairly coarse and deep with a sharp root angle. This end also has a circumferential chamfer  46 , on the outside of the cylinder to aid in engaging the inside of hole  52  (FIG. 3) thru mounting surface  18 . Flange  48  has two small diametrically opposed holes  40  in the annular face to accommodate a spanner wrench for the purposes of tightening the body to the mounting surface. 
     The second coupling  32  (FIGS. 4 and 5) differs from coupling one by the way it attaches to the mounting surface. Radially extending flange  50  has several holes  34  for fasteners  42 , there is also a concentric raised shoulder  38  at the base of the threaded barrel  20  to center the connection in surface mounting hole  52 . Gland nut  36  is identical to  14  in every respect except it has no hex flats on the outside, instead it has small recesses  40  for the use of a spanner wrench. 
     The third coupling shown in FIG. 6 is a variation that differs in the method of attaching to rod  16  by having a integral radially split clamping collar  54  with cap screw  56 . When screw  56  is tightened the collar contracts and grasps the rod. All other aspects of coupling three are similar to one and two. 
     All three couplings can be manufactured from either metallic or non-metallic material. The most economical way most likely being injection molding. 
     Although the above couplings imply a supported surface made of wood, a surface or element of another material can easily be adapted to. FIG. 7 gives an example of how the connection might be used in a shelving system. 
     It is an important object of the invention that a connection be provided that when locked offers significant resistance to axial displacement and yet can be easily unlocked and repositioned. Also, the rigidity of the connection to the surface that it is mounted on offers resistance to racking in free standing shelves. 
     While the couplings have been described, it is apparent that many modifications and configurations are possible without departing from the spirit of the invention.