Board to board coupling structure

A board to board coupling structure for coupling at least two panel assemblies, each having a rectangular frame structure composed of a horizontal top rail, a horizontal bottom rail, two vertical side rails, and four angle connectors connected between said horizontal top and bottom rails and said vertical side rails in four corners, the board to board coupling structure comprising:

• a tubular shaft having a longitudinal groove of substantially C-shaped cross section extending between two opposite ends thereof on the outside;
• two locating plates fixedly mounted in the longitudinal groove at desired locations;
• two inner socket assemblies respectively mounted on said tubular shaft, each of said inner socket assemblies comprising a socket body, an outer race, and an arched block connected between said socket body and said outer race, said socket body having threads raised from an outside wall thereof, said outer race having a top notch;
• two end caps respectively mounted on said tubular shaft, each of said end caps comprising a cap body having a receiving chamber, a rim formed integral with said cap body extending around said receiving chamber, and two toothed blocks extending from said rim into said receiving chamber;
• two outer sockets, each of said outer sockets comprising an annular base defining an open chamber, the annular base having an upright flange with a notch therein, and an annular retaining member mounted in said open chamber within said annular base and fixedly fastened to one of the two locating plates;
• a plurality of hook plates, each of said hook plates comprising a mounting base configured to be fixedly fastened to one vertical side rail, a hooked portion, and an angled connecting portion connected between said mounting base and said hooked portion;
• and
• a plurality of plug plates, each of said plug plates comprising a vertical plug portion at a bottom side, a vertical mounting portion at a top side configured to be fixedly fastened to one vertical side rail, and a horizontal connecting portion connected between said vertical plug portion and said vertical mounting portion;
• wherein the hooked portion of one of said plurality of hook plates is hooked on the top notch of the outer race of a first one of said two inner sockets and the hooked portion of another of said plurality of hook plates is hooked on the notch in the upright flange of a first one of said two outer sockets, the plug portion of one of said plurality of plug plates is inserted in between the socket body and outer race of a second one of said two inner sockets and the plug portion of another of said plurality of plug plates is engaged into the notch in the upright flange of a second one of said two outer sockets, and the toothed blocks of said two end caps are respectively inserted in gaps between the threads of the socket body of said two inner sockets and then into engagement with the threads of the socket body of said two inner sockets, enabling said at least two panel assemblies to be respectively coupled to and turned about said tubular shaft.