Abstract:
A multipurpose electric adapter is disclosed to include a housing holding two main metal power lead frames and a main metal grounding lead frame near a bottom side and two supplementary power lead frames and a supplementary grounding lead frame respectively connected to the main metal power and grounding lead frames at the top, a back plate fastened to the back side of the housing with the power and grounding prongs disposed in contact with the main metal power and grounding lead frames and extended out of the housing for connection to an electric outlet, and a faceplate covered on the front side of the housing, the faceplate having plug terminal insertion holes corresponding to the main metal power and grounding lead frames and the supplementary metal power and grounding lead frames for receiving any of a variety of electric plugs used in different countries around the world.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to electric sockets/plugs and, more particularly, to a multipurpose electric adapter for connecting one of a set of electric sockets to one of a set of electric plugs.  
           [0003]    2. Description of the Related Art  
           [0004]    The development of industry follows with the development of technology. Nowadays, various electronic apparatus have been disclosed, and have appeared on the market. These apparatus use an electric plug or electric socket to obtain power supply. However, an electric plug/socket for use in one country may not suitable for use in another country because different countries may use electric outlets of different specifications. There are DC-AC power adapter, UPS and AVR manufacturers who have their products equipped with a universal socket that fits different electric plugs. However, the known universal sockets cannot fit all countries around the world.  
           [0005]    FIGS.  14 ˜ 16  show an electric adapter for use to connect one of a set of electric plugs to one of a set of electric sockets according to the prior art. This structure of electric adapter  8  is comprised of a housing  82 , a set of metal power lead frames  84  and a metal grounding lead frame  85  mounted in the front side of the housing  82 , a plurality of metal contact spring plates  86  respectively mounted in terminal slots  821  in the back side of the housing  82  and disposed in contact with the rear contact faces  841  and  851  of the metal power lead frames  84  and the metal grounding lead frame  85 , a face (socket) place  81  covered on the front side of the housing  82 , and a back (plug) plate  83  covered on the back side of the housing  82 . The back plate  83  comprises two metal power blades  831  and a grounding prong  832  perpendicularly outwardly extended from the outer side. The metal power blades  831  and the grounding prong  832  have a respective inner contact end  8311  or  8321  respectively forced into contact with the metal contact spring plates  86 . This design of electric adapter has numerous drawbacks as follows:  
           [0006]    1. Because the metal power blades and grounding prong of the back plate are respectively electrically connected to the metal power lead frames and the metal grounding lead frame through the metal contact spring plates, much impedance is produced, resulting in low conducting efficiency.  
           [0007]    2. This structure of electric adapter is not durable in use because the metal contact spring plates start to wear quickly with use.  
           [0008]    3. Because a number of component parts are used, the assembly process of this structure of electric adapter is complicated.  
           [0009]    4. This structure of electric adapter has limited applications because it does not fit electric plugs of South Africa specifications or Australia/New Zealand specifications.  
         SUMMARY OF THE INVENTION  
         [0010]    The present invention has been accomplished under the circumstances in view, It is the main object of the present invention to provide a multipurpose electric adapter, which fits electric plugs of South Africa specifications as well as Australia/New Zealand specifications and specifications of various other countries. It is another object of the present invention to provide a multipurpose electric adapter, which is easy and inexpensive to manufacture. According to one aspect of the present invention, the multipurpose electric adapter comprises an electrically insulative housing, the housing comprising a plurality of open chambers; two main metal power lead frames and a main metal grounding lead frame respectively mounted in the open chambers of the housing, the main metal power lead frames being spaced from the main metal grounding lead frame at two opposite lateral sides, the main metal power lead frames each comprising a top hook, a back contact portion disposed in contact with the inner contact end of one metal power prong of the back plate, a transverse metal contact clamp formed of a horizontal upper front contact portion and a horizontal lower front contact portion, a side contact portion disposed at one side of the transverse metal contact clamp to form a vertical metal contact clamp, the main metal grounding lead frame comprising a transverse receiving portion, a longitudinal receiving portion disposed below the transverse receiving portion, a back metal contact spring strip disposed in contact with the inner contact end of the metal grounding prong, and a back spring strip; a faceplate covered on a front side of the housing, the faceplate having a set of main grounding terminal holes corresponding to the main metal grounding lead frame, the main grounding terminal holes including two big main grounding terminal holes vertically connected in a line and two small main grounding terminal holes vertically spaced below the big main grounding terminal holes and aligned with the big main grounding terminal holes in a line, and two main power terminal holes arranged in parallel at two sides of the small main grounding terminal slots corresponding to the transverse metal contact clamps and vertical metal contact clamps of the main metal power lead frames; and a back plate fastened to a back side of the housing, the back plate comprising two metal power prongs and a metal grounding prong for connection of an electric outlet, the metal power prongs and metal grounding prong of the back plate each having an inner contact end respectively disposed in contact with the main metal power lead frames and the main grounding lead frame. According to another aspect of the present invention, the main metal power lead frames each further comprise an oblique front metal contact clamp formed of a first oblique front contact portion extended from the side contact portion of the respective main metal power lead frame and a second oblique front contact portion extended from the lower front contact portion of the respective main metal power lead frame, and the faceplate further comprises two oblique power terminal holes corresponding to the oblique front metal contact clamps of the main metal power lead frames to fit an electric plug of Australia/New Zealand specifications. According to still another aspect of the present invention, two supplementary metal power lead frames and a supplementary metal grounding lead frame are provided in the housing to fit an electric plug of South Africa specifications.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is an exploded view of a multipurpose electric adapter according to a first embodiment of the present invention.  
         [0012]    [0012]FIG. 2 is a front view of the faceplate for the multipurpose electric adapter shown in FIG. 1.  
         [0013]    [0013]FIG. 3 is a front view of an alternate form of the faceplate for the multipurpose electric adapter according to the present invention.  
         [0014]    [0014]FIG. 4 is a schematic drawing showing the use of the present invention with an electric plug of South Africa specifications.  
         [0015]    [0015]FIG. 5 is a schematic drawing showing the use of the present invention with an electric plug of Australia/New Zealand specifications.  
         [0016]    [0016]FIG. 6 is a schematic drawing showing the use of the present invention with an electric plug of UK specifications.  
         [0017]    [0017]FIG. 7 is a schematic drawing showing the use of the present invention with an electric plug of US specifications.  
         [0018]    [0018]FIG. 8 is a schematic drawing showing the use of the present invention with an electric plug of European specifications.  
         [0019]    [0019]FIG. 9 is an exploded view of a multipurpose electric adapter according to a second embodiment of the present invention.  
         [0020]    [0020]FIG. 10 is an exploded view of a multipurpose electric adapter according to a third embodiment of the present invention.  
         [0021]    [0021]FIG. 11 is a sectional assembly view of the multipurpose electric adapter according to the third embodiment of the present invention.  
         [0022]    [0022]FIG. 12 is another sectional assembly view of the multipurpose electric adapter according to the third embodiment of the present invention.  
         [0023]    [0023]FIG. 14 is an exploded view of an electric adapter according to the prior art.  
         [0024]    [0024]FIG. 15 is a sectional assembly view of the electric adapter according to the prior art.  
         [0025]    [0025]FIG. 16 is another sectional assembly view of the electric adapter according to the prior art. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    Referring to FIGS. 1, 2,  4 , and  5 , an electric adapter  1  is shown comprised of a faceplate  11 , an electrically insulative housing  12 , a back (plug) plate  123 , two main metal power lead frames  13 , a main metal grounding lead frame  14 , two supplementary metal grounding lead frame  15 , and two supplementary metal power lead frames  16 .  
         [0027]    The housing  12  has a plurality of back open chambers  121  and  122  adapted to accommodate the main metal power lead frames  13 , the main metal grounding lead frame  14 , the supplementary metal grounding lead frame  15 , and the supplementary metal power lead frames  16 .  
         [0028]    The back plate  123  is detachably fastened to the back side of the housing  12 , having two metal power prongs  124  and a metal grounding prong  125  for connection of an electric outlet. The prongs  124  and  125  each have an inner contact end  1241  or  1251  respectively suspended in the back open chambers  121  and  122  of the housing  12 .  
         [0029]    The two main metal power lead frames  13  and the main metal grounding lead frame  14  are respectively mounted in the back open chambers  121  and  122  of the housing  12  near the bottom. The main metal power lead frames  13  are spaced from the main metal grounding lead frame  14  at two opposite lateral sides, each comprising a top hook  134 , a back contact portion  135  disposed in contact with the inner contact end  1241  of one metal power prong  124  of the back plate  123 , a transverse metal contact clamp  131  formed of a horizontal upper front contact portion  1311  and a horizontal lower front contact portion  1312 , a side contact portion  1321  disposed at one side of the transverse metal contact clamp  131  to form a vertical metal contact clamp  132 , and an oblique front metal contact clamp  133  formed of a first oblique front contact portion  1322  extended from the side contact portion  1321  and a second oblique front contact portion  1313  extended from the lower front contact portion  1312 .  
         [0030]    The main metal grounding lead frame  14  comprises a transverse receiving portion  141 , a longitudinal receiving portion  142  disposed below the transverse receiving portion  141 , a back metal contact spring strip  143  disposed in contact with the inner contact end  1251  of the metal grounding prong  125 . The back metal contact spring strip  143  has a mounting hole  1431  in the top free end.  
         [0031]    The supplementary metal grounding lead frame  15  is mounted inside the housing  12  above the main metal grounding lead frame  14 , having a bottom mounting portion  151  riveted to the mounting hole  1431  of the back metal contact spring strip  143  of the main metal grounding lead frame  14 .  
         [0032]    The supplementary metal power lead frames  16  are respectively mounted in the housing  12  above the main metal power lead frames  13 , each having a bottom hook  161  respectively hooked up with the top hooks  134  of the main metal power lead frames  13 .  
         [0033]    The faceplate  11  is covered on the housing  12  to close the receiving chambers  121  and  122 , having a set of main grounding terminal holes  111  corresponding to the main metal grounding lead frame  14 , the main grounding terminal holes  111  including two big main grounding terminal holes  1111  vertically connected in a line and two small main grounding terminal holes  1112  vertically spaced below the big main grounding terminal holes  1111  and aligned with the big main grounding terminal holes  1111  in a line, two main power terminal holes  112  arranged in parallel at two sides of the small main grounding terminal slots  1112  corresponding to the transverse metal contact clamps  131  and vertical metal contact clamps  132  of the main metal power lead frames  13 , two oblique power terminal holes  1121  respectively obliquely extended from the main power terminal holes  112  toward each other and spaced from each other at a distance corresponding to the oblique front metal contact clamps  133  of the main metal power lead frames  13 , two supplementary power terminal holes  113  equally spaced from the big main grounding terminal holes  1111  at two opposite lateral sides corresponding to the supplementary metal power lead frames  16 , and a supplementary grounding terminal hole  114  spaced above the big main grounding terminal holes  1111  corresponding to the supplementary metal grounding lead frame  15 .  
         [0034]    Referring to FIG. 5 and FIG. 1 again, the multipurpose electric adapter  1  can be used with an electric plug  3  of Australia/New Zealand specifications. When fastening the electric plug  3  to the multipurpose electric adapter  1 , the grounding prong  32  of the electric plug  3  is inserted through the top big main grounding terminal hole  1111  into the transverse receiving portion  141  of the main metal grounding lead frame  14 , and the two power prongs  31  of the electric plug  3  are respectively inserted through the oblique power terminal holes  1121  into the oblique front metal contact clamps  133  of the main metal power lead frames  13 .  
         [0035]    Referring to FIG. 6 and FIG. 1 again, the multipurpose electric adapter  1  can be used with an electric plug  4  of UK specifications. When fastening the electric plug  4  to the multipurpose electric adapter  1 , the grounding prong  42  of the electric plug  4  is inserted through the big main grounding terminal holes  1111  into the transverse receiving portion  141  of the main metal grounding lead frame  14 , and the two power prongs  41  of the electric plug  4  are respectively inserted through the main power terminal holes  112  into the transverse metal contact clamps  131  of the main metal power lead frames  13 .  
         [0036]    Referring to FIG. 7 and FIG. 1 again, the multipurpose electric adapter  1  can be used with an electric plug  5  of US specifications. When fastening the electric plug  5  to the multipurpose electric adapter  1 , the grounding prong  52  of the electric plug  4  is inserted through the top big main grounding terminal hole  1111  into the transverse receiving portion  141  of the main metal grounding lead frame  14 , and the two power prongs  51  of the electric plug  4  are respectively inserted through the main power terminal holes  112  into the vertical metal contact clamps  132  of the main metal power lead frames  13 .  
         [0037]    Referring to FIG. 8 and FIG. 1 again, the multipurpose electric adapter  1  can be used with an electric plug  6  of European specifications. When fastening the electric plug  6  to the multipurpose electric adapter  1 , the grounding prong  62  of the electric plug  6  is inserted through the bottom small main grounding terminal holes  1112  into the longitudinal receiving portion  142  of the main metal grounding lead frame  14 , and the two power prongs  61  of the electric plug  6  are respectively inserted through the main power terminal holes  112  into the transverse metal contact clamps  131  of the main metal power lead frames  13 .  
         [0038]    Further, the supplementary metal grounding lead frame  15  and the supplementary metal power lead frames  16  match with the supplementary power terminal holes  113  and supplementary grounding terminal hole  114  of the faceplate  11  to receive an electric plug of South Africa specifications.  
         [0039]    [0039]FIG. 9 is an exploded view of a multipurpose electric adapter according to the second embodiment of the present invention. As illustrated, the multipurpose electric adapter is comprised of a housing  12 , a main metal grounding lead frame  14  and two main metal power lead frames  13  respectively mounted in the housing  12  (the main metal grounding lead frame  14  and the main metal power lead frames  13  are same as that shown in FIG. 1), and a faceplate  11  covered on the housing  12 . The faceplate  11  has a set of main grounding terminal holes  111  corresponding to the main metal grounding lead frame  14 , the main grounding terminal holes  111  including two big main grounding terminal holes  1111  vertically connected in a line and two small main grounding terminal holes  1112  vertically spaced below the big main grounding terminal holes  1111  and aligned with the big main grounding terminal holes  1111  in a line, two main power terminal holes  112  arranged in parallel at two sides of the small main grounding terminal slots  1112  corresponding to the transverse metal contact clamps and vertical metal contact clamps of the main metal power lead frames  13 , and two oblique power terminal holes  1121  respectively obliquely extended from the main power terminal holes  112  toward each other and spaced from each other at a distance corresponding to the oblique front metal contact clamps of the main metal power lead frames  13 . This embodiment eliminates the design for South Africa specifications. Further, the main metal power lead frames  13  may be made having a respective vertical contact portion  136  respectively aimed at a respective insertion hole  126  in the peripheral wall of the housing  12  to receive an electric plug without grounding prong. The faceplate  11 A shown in FIG. 3 may be used to substitute for the faceplate  11  shown in FIG. 9.  
         [0040]    FIGS.  10 ˜ 12  show a multipurpose electric adapter according to the third embodiment of the present invention. According to this embodiment, the multipurpose electric adapter is comprised of a housing  72 , two main metal power lead frames  13  and a main metal grounding lead frame  14  respectively mounted in respective open chambers  721  and  722  in the housing  12 , a faceplate  71  covered on the front side of the housing  72 , and a back (plug) plate  73  covered on the back side of the housing  72 . The back plate  73  comprises two metal power blades  731  and a grounding prong  732  perpendicularly outwardly extended from the outer side. The metal power blades  731  and the grounding prong  732  have a respective inner contact end  7311  or  7321  respectively forced into contact with respective contact portions  135  and  143  of the lead frames  13  and  14 . Further, the main metal power lead frames  13  each have a vertical contact portion  136  respectively aimed at a respective insertion hole  726  in the peripheral wall of the housing  72 .  
         [0041]    A prototype of multipurpose electric adapter has been constructed with the features of FIGS.  1 ˜ 13 . The multipurpose electric adapter functions smoothly to provide all of the features discussed earlier.  
         [0042]    Although particular embodiments of the invention have 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.