Abstract:
A universal plug adapter is provided plugs of different specifications to be selectively extracted and positioned to meet and connect an external wall socket. The plug thus supplies power to a railed recess, in which railed recess a rail-positioned socket having different specifications is installed and electrically connected, so as to form the universal plug adapter. Therein, the rail-positioned socket has sockets of different specifications for plugs of different specifications to insert. Additionally, the rail-positioned socket rail-positioned socket may be tailed with a functional electric device, such as a nightlight, an alarm, a wireless router, a USB socket or sockets of different specifications, for easy and convenient use.

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a universal plug adapter for adapting plugs of various specifications to different wall sockets. 
     2. Description of Related Art 
     Presently, different specifications of plugs and sockets are adapted in different countries. Since electric appliances have been widely circulated all over the world, when an imported electric appliance with a plug not conforming with the local socket specification, a plug adapter is necessary for electric connection between the electric appliance and the grid. As there are so many different specification of plugs used in different countries, a user may have to prepare that many plug adapters for proper electric connection. 
     On the other hand, travel for both business and leisure purposes is common nowadays, and when people travel with their own laptop computers, mobile phones and other portable electric devices, the difference between specifications for power plugs and sockets in different countries, such as Japan and UK, can cause significant inconvenience because plural plug adapters have to be bought and carried in the luggage. 
     In view of the shortcomings of the existing devices to be improved, the inventor of the present invention deliberated solutions for enhancing practicability and convenience in use. After his repeated researches and tests, a universal plug adapter that meets specifications for power plugs and sockets in different countries as disclosed herein was invented. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a universal plug adapter, which includes plugs of different specifications to be selectively extracted and positioned to meet and connect an external wall socket further associated to a power source, so that the rail-positioned sockets that have different specifications and are selectively installed in the railed recess can be powered by the power source, thereby achieving easy and convenient use. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when acquire in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an exploded view of a universal plug adapter according to the present invention; 
         FIG. 2  is another exploded view of the universal plug adapter according to the present invention; 
         FIG. 3  is a perspective view of a Specification-B plug according to the present invention; 
         FIG. 4  is a perspective view of a rail-positioned socket according to the present invention; 
         FIG. 5  is a perspective view of a lower shell unit according to the present invention; 
         FIG. 6  is an exploded view of a Specification-C plug according to the present invention; 
         FIG. 7  is a perspective view showing embodiments of the rail-positioned socket according to the present invention; 
         FIG. 8  is a schematic view showing switch of the Specification-C plug; 
         FIG. 9  is a cross-sectional view of the Specification-C plug taken along Line A-A of  FIG. 8 ; 
         FIG. 10  is a schematic view showing switch of the Specification-B plug; 
         FIG. 11  is a cross-sectional view of the Specification-B plug taken along Line B-B of  FIG. 10 ; 
         FIG. 12  is a schematic view showing switch of the Specification-A plug; and 
         FIG. 13  is a cross-sectional view of the Specification-A plug taken along Line C-C of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  are exploded views of a universal plug adapter according to the present invention. The universal plug adapter comprises the following components. 
     A lower shell unit  10  (referring to  FIG. 5 ) has primarily therein an A-terminal hole  101 , B-terminal holes  102  and C-terminal holes  103 , a movable rail portion  104  at one side thereof with a protrusion  104   a , a plurality of posts  101   a ,  102   a  and  103   a  mounted therearound with springs  21 ,  22  and  23 , and two metal conducting plates  30  and  31  inlaid and extending along edges of the A-terminal hole  101 , B-terminal holes  102  and C-terminal holes  103 . The two metal conducting plates  30  and  31  are formed with conducting clamps  32 ,  33  and  34  near the edges of the A-terminal hole  101 , B-terminal holes  102  and C-terminal holes  103 . In addition, the metal conducting plate  30  has one end bent upward to form a power-source clamp  30   a , and the other metal conducting plate  31  has one end bent upward to form an abutting portion  31   a  to abut against a fuse  40 . Moreover, a power-source clamp  30   b  is provided above the fuse  40 . 
     A Specification-A plug  51  (also referring to  FIGS. 5 and 13 ) has a base  501  and two terminals  502  each mounted therearound with a spring  50 . The two terminals  502  are extended with pins  502   a  for engaging and electrically connecting the conducting clamps  32  of the two metal conducting plates  30  and  31 . The base  501  is centrally formed with an axial tube  501   e , and unilaterally formed with an inclined plane  501   a  as well as a pressing lever  501   b . The base  501  centrally has a downward extended hooked plate  501   c  that is provided with a hook  501   d . In addition, a casing  503  is formed with two axially extending holes for movably receiving the two terminals  502  therein. The casing  503  further has a hook  503   a  for engaging the hook  501   d  on the hooked plate  501   c  of the base  501  so as to restrict the terminals  502  of the base  501  from leaving the casing  503 . The casing  503  has a ledge  504  near the top thereof and the ledge  504  is formed with a through hole  504   a . The through hole  504   a  together with the axial tube  501   e  of the base  501  is for the post  101   a  of the lower shell unit  10  to insert, while the casing  503  of the Specification-A plug  51  is movable to and fro with respect to the A-terminal hole  101 . 
     A Specification-B plug  53  (also referring to  FIGS. 3 ,  5  and  11 ) has a base  530  and a plurality of terminals  531  attached to the base  530 . Each said terminal  531  has an extended pin  531   a  for correspondingly inserting to and electrically connecting the conducting clamps  33  of the metal conducting plates  30  and  31  in the lower shell unit  10 . The base  530  is centrally formed with an axial tube  530   b , and unilaterally formed with a positioning block  530   c  as well as a pressing lever  530   d . Therein, the axial tube  530   b  is for the post  102   a  of the lower shell unit  10  to insert while the terminals  531  of the Specification-B plug  53  are removable to and fro with respect to the B-terminal holes  102  in the lower shell unit  10 . 
     A Specification-C plug  52  (also referring to  FIGS. 5 ,  6  and  9 ) has a base  520  formed with two recesses  520   a , slots  520   b  and notches  520   c  each at a side of one of the recesses  520   a . The base  520  is unilaterally formed with an inclined plane  520   d  and a pressing lever  520   e . Two conducting pins  521  each include a top panel  521   a  formed with a slot  521   b . The top panel  521   a  has raised and depressed portions and has a pin  521   c  to be inserted to and thereby positioned in the notch  520   c  of the base  520 . The pins  521   c  of the conducting pins  521  are for being inserted to and electrically connected with the conducting clamps  34  of the two metal conducting plates  30  and  31  in the lower shell unit  10 . Therein, the slots  520   b  in the two recesses  520   a  of the base  520  together with the slots  521   b  on the top panels  521   a  are for positioning T-shaped retainers  522   b  and in turn axial columns  522   a  of the terminals  522  by inserting and then rotating the T-shaped retainers  522   b  in the slots  520   b  and  521   b , so as to make the two terminals positioned in parallel. Therein, the raised portions of the top panel  521   a  abut against the T-shaped retainer  522   b  for preventing looseness. The two terminals  522  are rotatable to form a splay configuration with each other, so as to be used as a plug of another specification. The base  520  is centrally formed with an axial hole  520   f  for the post  103   a  of the lower shell unit  10  to insert while the terminals  522  of the Specification-C plug  52  are movable to and fro with respect to the B-terminal holes  103  in the lower shell unit  10 . 
     A movable locking plate  54  is formed with a plurality of guiding surfaces  54   a ,  54   b ,  54   c  and engaging notches  541   a ,  541   b ,  541   c . Each of the guiding surfaces  54   a ,  54   b ,  54   c  includes a slanting section followed by a vertical section that connects the corresponding engaging notch  541   a ,  541   b  or  541   c . In addition, a spring  56   a  is mounted around a post at one side of the bottom of the movable locking plate  54  while a bottom plate  542  juts out of an opposite side of the bottom of the movable locking plate  54 . The movable locking plate  54  is received in the movable rail portion  104  of the lower shell unit  10  in a transversely to-and-fro movable manner. 
     A movable positioning unit  59  has its bottom formed with a spring seat for receiving a W-shaped spring  60 . The movable positioning unit  59  has its top formed with two oblique abutting surfaces  591 ,  592  and a dent  593  therebetween. Furthermore, the movable positioning unit  59  is to be received in the movable rail portion  104  of the lower shell unit  10  with one side of the bottom of the movable positioning unit  59  pressing on the bottom plate  542  of the movable locking plate  54 . Meantime, the W-shaped spring  60  at the other side with a middle depressed part inserted in and positioned by the protrusion  104   a  of the movable rail portion  104  in the lower shell unit  10 . The movable positioning allows the W-shaped spring  60  to push the movable positioning unit  59  to bilaterally move. 
     An upper shell unit  57  has vertically formed with a plurality of through holes for allowing the pressing levers  501   b ,  520   e ,  530   d  of the Specification-A plug  51 , Specification-B plug  52 , and Specification-C plug  53  to move therein. The upper shell unit  57  further has atop a railed recess  57   a , which has bilaterally rails  57   b  and has two notches  57   c  facing an opening thereof so that upon combination between the upper shell unit  57  and the lower shell unit  10 , the notches  57   c  serve to receive and position the power-source clamp  30   a  of the metal conducting plate  30  and the power-source clamp  30   b  of the metal conducting plate  31 . 
     A rail-positioned socket  58  (also referring to  FIG. 4 ) has sockets of various specifications. The rail-positioned socket  58  has bilaterally grooves  58   a  and has its bottom formed with two raised abutting pins  58   b . Therein, the grooves  58   a  are for engaging the rails  57   b  of the upper shell unit  57  while the abutting pins  58   b  are for being inserted in and electrically connected to the power-source clamps  30   a ,  30   b  positioned in the notches  57   c . Moreover, the rail-positioned socket  58  may be optionally tailed with various functional electric devices, such as a nightlight, an alarm, a wireless router, a USB socket or sockets of different specifications ( FIG. 7 ) for easy and convenient use. 
     As shown in  FIGS. 8 and 9  (also referring to  FIG. 1 ), as a result of pressing the pressing lever  520   e  of the Specification-C plug  52  downward, the entire Specification-C plug  52  is lowered. The guiding surfaces  54   c  of the movable locking plate  54  replaced under the pushing force of the pressing lever  520   e . The Specification-C plug  52  smoothly descends and its two terminals  522  thus jut out of the lower shell unit  10 . At this time, the two pins  521   c  are engaged by the conducting clamps  34 , and the spring  56  of the movable locking plate  54  pushes the movable locking plate  54  to its initial position. Thereby, the engaging notch  541   c  holds and positions the pressing lever  520   e  while the oblique abutting surface  592  of the movable positioning unit  59  abuts against the inclined plane  520   d  of the Specification-C plug  52  so as to reinforce the combination. 
     As shown in  FIGS. 10 and 11  (also referring to  FIG. 1 ), by pressing the pressing lever  530   d  of the Specification-B plug  53  downward, the entire Specification-B plug  53  is lowered. The guiding surfaces  54   b  of the movable locking plate  54  is replaced under the pushing force of the pressing lever  530   d . The Specification-B plug  53  smoothly descends and its terminals  531  jut out of the lower shell unit  10 . The two pin  531   a  thus are engaged by the conducting clamps  33 . At this time, the entire Specification-C plug  52  is lifted and positioned, and the spring  56  of the movable locking plate  54  pushes the movable locking plate  54  back to its initial position to make its engaging notch  541   b  position the pressing lever  530   d  while the dent  593   a  of the movable positioning unit  59  receives the positioning block  530   c  of the Specification-B plug  53 . 
     As shown in  FIGS. 12 and 13  (also referring to  FIG. 1 ), pressing the pressing lever  501   b  of the Specification-A plug  51  lowers the entire Specification-A plug  51 . The guiding surfaces  54   a  of the movable locking plate  54  is pushed to replace by the pressing lever  501   b . The Specification-A plug  51  smooth descends so the terminals  502  are lowered and thus jut out of the lower shell unit  10 . The two pins  502   a  are engaged by the conducting clamps  32 . At this time, the entire Specification-B plug  53  is lifted and positioned, and the spring  56  of the movable locking plate  54  pushes the movable locking plate  54  back to its initial position to make its engaging notch  541   a  position the pressing lever  501   b . Meantime, the oblique abutting surface  591  of the movable positioning unit  59  abuts against the inclined plane  501   a  of the Specification-A plug  51  so as to ensure the engagement.