Abstract:
A light steel ceiling rack formed of first frame bars and second frame bars, each second frame bar having respective second horizontal top flanges terminating in beveled end edges for engaging into respective notches in the first frame bars and respective first horizontal top flanges provided with end projections for stopping below respective first horizontal top flanges of the first frame bars upon insertion of end plug strips of the second frame bars into respective mounting holes of the first frame bars to enhance the connection and to prevent formation of a gap in the connection area between each first frame bar and each second frame bar.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
   The present invention relates to a light steel ceiling rack and, more particularly to an improved structure of light steel ceiling rack, which has the connection between the first frame bar and the second frame bar cause a sense of beauty. 
     FIG. 1  illustrates the arrangement of a light steel ceiling rack according to the prior art. This design has drawbacks. After connection of the end plug strip  41  to the mounting hole  31  of, the first frame bar  3 , a gap may exist between the end edge  421  of the flange  42  of the second frame bar  4  and the side edge  321  of the flange  32  of the first frame bar  3  due to inaccurate positioning or tolerance of size, thereby obstructing the sense of beauty and admitting light. Another drawback is the unstable connection between the end plug strip  41  and the mounting hole  31 . Further, the base (body)  30  of the first frame bar  3  is formed of two plate members arranged in a stack, and the base (body) of the second frame bar  4  is also formed of two plate members arranged in stack. Both the first frame bar  3  and the second frame bar  4  have a low toughness, thereby lowering the structural strength. 
   Therefore, it is desirable to provide a light steel ceiling rack that eliminates the aforesaid drawbacks. 
   The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a light steel ceiling rack, which has a high structural strength. It is another object of the present invention to provide a light steel ceiling rack, which eliminates the formation of a gap in between the first frame bar and the second frame bar after their connection, thereby causing a sense of beauty. 
   According to one aspect of the present invention, the light steel ceiling rack is formed of first frame bars and second frame bars. Each second frame bar has respective second horizontal top flanges terminating in beveled end edges for engaging into respective notches in the first frame bars, and respective first horizontal top flanges provided with end projections for stopping below respective first horizontal top flanges of the first frame bars upon insertion of end plug strips of the second frame bars into respective mounting holes of the first frame bars to enhance the connection and to prevent formation of a gap in the connection area between each first frame bar and each second frame bar. 
   According to another aspect of the present invention, the two elongated flat base plates of each of the first and second frame bars include a first elongated flat base plate and a second elongated flat base plate. The first elongated flat base plate comprises a plurality of raised portions. The second elongated flat base plate comprises a plurality of recessed portions respectively forced into engagement with the raised portions of the first elongated flat base plate of the respective second frame bar. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of the prior art design. 
       FIG. 2  is an exploded view of a part of the preferred embodiment of the present invention. 
       FIG. 3  is an assembly view of  FIG. 2 . 
       FIG. 4  is another assembly view of  FIG. 2  viewed from another angle. 
       FIG. 5  is an elevational view of one second frame bar for the light steel ceiling rack according to the present invention. 
       FIG. 6  is a top plain view of the assembly shown in  FIG. 3 . 
       FIG. 7  is an elevational view of one first frame bar for the light steel ceiling rack according to the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIGS. 2˜7 , a light steel ceiling rack in accordance with the present invention is shown comprised of a plurality of first frame bars  1  and a plurality of second frame bars  2  respectively perpendicularly connected to the first frame bars  1 . 
   The first frame bars  1  are T-bars, each comprising two elongated flat base plates  11  attached together, a bottom track  10  longitudinally formed integral with the bottom sides of the elongated flat base plates  11 , two first horizontal top flanges  12  respectively outwardly extended from the top sides of the elongated flat base plates  11  in reverses directions, two vertical top flanges  13  respectively upwardly extended from the outer sides of the first horizontal top flanges  12 , two second horizontal top flanges  14  respectively inwardly extended from the top sides of the vertical top flanges  13  and spaced from each other at a distance, a plurality of hanging holes  15  and a plurality of mounting holes  17  cut through the elongated flat base plates  11 , an end stop flange  182  transversely disposed at each of the two distal ends, an end plug strip  181  disposed at each of the two ends, and a springy retaining tong  183  provided at each end plug strip  181 . 
   The second frame bars  2  are T-bars, each comprising two elongated flat base plates  21  attached together, a bottom track  20  longitudinally formed integral with the bottom sides of the elongated flat base plates  21 , two first horizontal top flanges  22  respectively outwardly extended from the top sides of the elongated flat base plates  21  in reverses directions, two vertical top flanges  23  respectively upwardly extended from the outer sides of the first horizontal top flanges  22 , two second horizontal top flanges  24  respectively inwardly extended from the top sides of the vertical top flanges  23  and spaced from each other at a distance, an end stop flange  282  transversely disposed at each of the two distal ends, an end plug strip  281  disposed at each of the two ends, and a springy retaining tong  283  provided at each end plug strip  281 . The end plug strips  281  of the second frame bars  2  are to be plugged into the mounting holes  17  of the first frame bars  1 . After insertion of one end plug strip  281  of one second frame bar  2  into one mounting hole  17  of one first frame bar  1 , the respective springy retaining tong  283  of the respective second frame bar  2  prohibits backward movement of the respective end plug strip  281  from the respective mounting hole  17 . 
   The main features of the present invention are outlined hereinafter. The vertical top flanges  13  of each first frame bar  1  each have a U-notch  131  corresponding to each mounting hole  17  of each first frame bar  1 . The second horizontal top flanges  14  of each first frame bar  1  each have a trapezoidal notch  141  corresponding to each mounting hole  17  of each first frame bar  1  and integral with the corresponding U-notch  131  of the corresponding vertical top flange  13 . The second horizontal top flanges  24  of each second frame bar  2  each have each end terminating in a beveled end edge  241 . The first horizontal top flanges  22  of each second frame bar  2  each have an end projection  221  at each of the two ends corresponding to the beveled end edge  241  at each end of each of the second horizontal top flanges  24 . 
   When inserted one end plug strip  281  of one second frame bar  2  into one mounting hole  17  of one first frame bar  1 , the corresponding beveled end edges  241  of the corresponding second horizontal top flanges  24  of the second frame bar  2  are respectively fastened to the trapezoidal notch  141  of one second horizontal top flange  14  of the first frame bar  1 , and the end projection  221  of the first horizontal top flanges  22  of the second frame bar  2  are respectively stopped at the bottom side  120  of one first horizontal top flange  12  of the first frame bar  1  (see  FIG. 4 ) to enhance the stability of the connection between the first frame bar  1  and the second frame bar  2  and to eliminate the formation of a gap in the connection area between the first frame bar  1  and the second frame bar  2 . 
   Further, one of the two elongated flat base plates  11  of each first frame bar  1  has a plurality of raised portions  111 , and the other of the two elongated flat base plates  11  of each first frame bar  1  has a plurality of recessed portions  112  corresponding to the raised portions  111 . The two elongated flat base plates  11  of each first frame bar  1  are fastened together by roller ramming to force the respective raised portions  111  into engagement with the respective recessed portions  112 . The engagement between the raised portions  111  and the recessed portions  112  enhances the tightness of the connection and the structural strength of the first frame bar  1 . 
   Further, one of the two elongated flat base plates  21  of each second frame bar  2  has a plurality of raised portions  211 , and the other of the two elongated flat base plates  21  of each second frame bar  2  has a plurality of recessed portions  212  corresponding to the raised portions  211 . The two elongated flat base plates  21  of each second frame bar  2  are fastened together by roller ramming to force the respective raised portions  211  into engagement with the respective recessed portions  212 . The engagement between the raised portions  211  and the recessed portions  212  enhances the tightness of the connection and the structural strength of the second frame bar  2 . 
   As indicated above, the invention achieves the following effects: 
   1. When inserted one end plug strip  281  of one second frame bar  2  into one mounting hole  17  of one first frame bar  1 , the corresponding beveled end edges  241  of the corresponding second horizontal top flanges  24  of the second frame bar  2  are respectively fastened to the trapezoidal notch  141  of one second horizontal top flange  14  of the first frame bar  1 , and the end projection  221  of the first horizontal top flanges  22  of the second frame bar  2  are respectively stopped at the bottom side  120  of one first horizontal top flange  12  of the first frame bar  1  to enhance the stability of the connection between the first frame bar  1  and the second frame bar  2  and to eliminate the formation in the connection area between the first frame bar  1  and the second frame bar  2 . 
   2. When the two elongated flat base plates  11  or  21  of each first or second frame bar  2  are fastened together by roller ramming, the respective raised portions  111  or  211  are engaged into the respective recessed portions  112  or  212 . The engagement between the raised portions  111  or  211  and the recessed portions  112  or  212  enhances the tightness of the connection and the structural strength of the frame bar  1  or  2 . 
   Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.