Patent Publication Number: US-7581977-B1

Title: Safety socket

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This present invention relates to a socket, and more specifically to a safety socket capable of preventing electric shock. 
   2. The Related Art 
   Electronic products have developed rapidly over the past few decades. With more sockets utilized than before, the safety structure is apparently important for the socket. Generally, an insertion hole of the socket has an electrode made by copper sheet for electrically connecting with a plug. Such socket can be electrically connected with the plug even if a terminal of the plug is not fully inserted into the insertion hole of the socket. As a result, it is easy to cause accidents, for example, electric shock happens when a user contacts the terminal during insertion or extraction of the plug unintentionally. So there is a need to design a socket which is able to prevent electric shock. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to provide a safety socket capable of preventing electric shock efficiently and being operated conveniently. The safety socket adapted for connecting with a terminal of a plug includes a socket housing with at least one electrode mounted thereon, a socket cover engaged with the socket housing, and a fixing case mounted in the socket housing. The socket cover has a plurality of insertion holes for allowing the terminals to pass therethrough. The fixing case includes an insulating housing and an electrode component. The electrode component has a pivotal portion pivoted on the insulating housing, a contacting portion and a pressing portion respectively extended from two opposite ends of the pivotal portion. The contacting portion is underlain the electrode with a small gap. The pressing portion is located under the corresponding insertion hole for being pressed downwardly by the inserted terminal to make the contacting portion be uplifted to electrically connect with the electrode. 
   As described above, the pressing portion is pressed downwardly by the terminal so that the contacting portion is uplifted to connect with the electrode electrically. Namely, the safety socket can be connected with the plug electrically only if the terminal is fully inserted into the safety socket so as to make the contacting portion be uplifted. Thus the terminal is not electrified before pressing the pressing portion, which effectively prevents the electric shock during the insertion or extraction of the plug. Furthermore, because this safety socket dose not require accessorial elements or other operations to achieve such function, the safety socket is more convenient for a user to operate. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, together with its objects and the advantages thereof may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which: 
       FIG. 1  is an exploded, perspective view of a safety socket of an embodiment in accordance with the present invention; 
       FIG. 2  is an exploded, perspective view of a fixing case of the safety socket shown in  FIG. 1 ; 
       FIG. 3  is an assembled, perspective view of the safety socket shown in  FIG. 1 , wherein a socket cover is removed; 
       FIG. 4  is a cross-sectional view illustrating a state of a plug incompletely inserted into the safety socket of  FIG. 1 ; 
       FIG. 5  is a partly enlarged view showing an enlarged V portion of  FIG. 4 ; 
       FIG. 6  is a partly enlarged view showing an enlarged VI portion of  FIG. 4 ; 
       FIG. 7  is a cross-sectional view illustrating a state of the plug fully inserted into the safety socket of  FIG. 1 ; and 
       FIG. 8  is a partly enlarged view showing an enlarged VIII portion of  FIG. 7 . 
   

   DETAILED DESCRIPTION OF THE EMBODIMENT 
   Referring to  FIG. 1 , an embodiment of a safety socket  1  according to the present invention is shown. The safety socket  1  includes a socket housing  10 , a first connection element  20 , a second connection element  30 , a third connection element  40 , a plurality of fixing cases  50  and a socket cover  60  engaged with the socket housing  10 . 
   The socket housing  10  has a basic plate  11  and a sidewall  12  enclosing the basic plate  11  to form a receiving chamber. A plurality of first, second and third receiving portions  13 ,  14 ,  15  are formed in the receiving chamber. The first receiving portions  13  are arranged at intervals in a first row and respectively define an opening facing a front of the socket housing  10 . The second receiving portions  14  are arranged at intervals in a second row spaced from the first row with a narrow gap and respectively define an opening facing a rear of the socket housing  10 . The third receiving portions  15  are formed at intervals in the second row. Each of the third receiving portions  15  is adjacent to the corresponding second receiving portion  14  and has a receiving space bigger than that of the second receiving portion  14 . The basic plate  11  further has a plurality of holding portions  16  for fixing the first connection element  20 , the second connection element  30  and the third connection element  40 , respectively. Each of the holding portions  16  has two holding holes  161  arranged abreast on a top thereof. 
   The first connection element  20  mounted in the first row has a first conductive portion  21 . The first conductive portion  21  is an elongated plate shape. A portion of a top edge of the first conductive portion  21  extends substantially perpendicular to the first conductive portion  21  to form a first fixing portion  22  for covering the top of the corresponding holding portion  16 . Middles of two sides of the first fixing portion  22  are bent downwardly to form buckling portions  23 . The buckling portion  23  is inserted into the corresponding holding hole  161  for fixing the first connection element  20  to the socket housing  10 . A bottom edge of the first conductive portion  21  has portions extending upwards to form a plurality of first electrodes  24 . The first electrode  24  is U-shaped and received in the corresponding first receiving portion  13  of the first row. 
   The second connection element  30  mounted in the socket housing  10  has a second conductive portion  31  of elongated plate shape. A top edge of the second conductive portion  31  extends substantially perpendicular to the first conductive portion  31  to form a second fixing portion  32  corresponding to the holding portion  16 . Middles of two sides of the second fixing portion  32  are bent downwardly to form buckling portions  33  inserted into the corresponding holding holes  161 . The top edge of the second conductive portion  31  further has portions extending substantially perpendicular to the second conductive portion  31  to form a plurality of second electrodes  34  corresponding to the third receiving portions  15 . The second electrode  34  is rectangular and has a mating hole  341  at a center thereof. 
   The third connection element  40  is mounted in the second row of the socket housing  10 . The construction of the third connection element  40  is somewhat analogous to that of the first connection element  20 . The difference between the first connection element  20  and the third connection element  40  is that the position of a third fixing portion  42  and third electrodes  44  of the third connection element  40  is arranged corresponding to the corresponding holding portion  16  and the second receiving portions  14  for securing the third connection element  40  to the socket housing  10  and placing the third electrodes  44  in the corresponding second receiving portions  14 . In addition, in this embodiment, the third electrodes  44  are smaller than the first electrodes  24 . 
   Please refer to  FIG. 1  and  FIG. 2 , the fixing case  50  includes an insulating housing  51 , an electrode component  53 , an accommodating frame  54  and an elastic component  55  mounted in the accommodating frame  54 . The insulating housing  51  has a rectangular bottom plate  511 , a first lateral plate  512  bending upwards from three edges of the bottom plate  511  and a second lateral plate  513  removably mounted at the bottom plate  511  to form a closed frame. In this embodiment, the closed frame also can be formed by the first lateral plate  512  enclosing the bottom plate  511 . The first lateral plate  512  and the second lateral plate  513  respectively have a pivotal recess  514  at a middle of a top thereof. The two pivotal recesses  514  facing each other are adapted for holding a pivotal shaft  52  thereon. The insulating housing  51  further has a supporting portion  515  and an accommodating portion  516  which are all located in the closed frame. The supporting portion  515  of substantial pillar-shape is located at one end of the bottom plate  511  and higher than the first lateral plate  512 . The accommodating portion  516  of cylindraceous shape is located at the other end of the bottom plate  511  and lower than the supporting portion  515 , receiving an elastic element  56  therein, such as a spring. Furthermore, the accommodating portion  516  and the supporting portion  515  are substantially aligned with each other. 
   The electrode component  53  defines a pivotal portion  531  pivoted on the pivotal shaft  52 . In this embodiment, the pivotal portion  531  may be manufactured by punching technology. One end of the pivotal portion  531  extends outwards to form a contacting portion  532 . The contacting portion  532  is disposed on the supporting portion  515  and has a portion protruding upwards to form a protrusion  5321  corresponding to the mating hole  341  for steady connection. The other end of the pivotal portion  531  extends parallel to the contacting portion  532  to form a pressing portion  533 . The pressing portion  533  is disposed lower than the contacting portion  532  and supported by the elastic element  56 . A free end of the pressing portion  533  has a portion curved to form a positioning portion  5331  of downward concave shape for preventing a terminal of a plug (not shown) from sliding thereon. 
   Please refer to  FIG. 2  and  FIG. 5 , the accommodating frame  54  placed above the insulating housing  51  is rectangular and has a through hole  541  for receiving the elastic component  55 . Two bottom sides of the through hole  541  extend inwards a predetermined distance to form a protruding portion  542 , respectively. The elastic component  55  may be made of insulating material or metal material, and has a bending portion  551 . The bending portion  551  of substantially U-shape, with an opening thereof narrowed, is placed in the through hole  541  for elastically clamping the inserted terminal. Two facing portions of a top side of the bending portion  551  are curved outwards to form a leading portion  552 , respectively, for conveniently inserting the terminal into the bending portion  551 . A bottom side of the bending portion  551  has two portions perpendicularly extending outwards to form a resistive portion  553  respectively. The resistive portion  553  is placed on the protruding portion  542  for carrying the elastic component  55 . 
   With reference to  FIG. 1 ,  FIG. 3  and  FIG. 5 , the first connection element  20 , the second connection element  30  and the third connection element  40  are received in the socket housing  10  in turn. The buckling portions  23 ,  33  and  43  are inserted into the holding holes  161 , respectively, for fixing the first connection element  20 , the second connection element  30  and the third connection element  40  into the socket housing  10 . The first and third electrodes  24  and  44  are respectively accommodated in the corresponding first receiving portions  13  and second receiving portions  14 . The second electrode  34  is suspended above the contacting portion  532  of the fixing case  50  received in the third receiving portion  15  with a small gap. The socket cover  60  with a plurality of insertion holes  61  for allowing the terminal to pass therethrough is engaged with the socket housing  10 . 
   Please refer to  FIG. 2 ,  FIG. 4  and  FIG. 6 , when a plug  2  is inserted into the safety socket  1 , a terminal  201  of the plug  2  is firstly pushed to pass through the bending portion  551  under the guidance of the leading portion  552  until the terminal  201  contacts the pressing portion  533 . In this process, because the contacting portion  532  is not connected with the second electrode  34 , the terminal  201  is not electrified and accordingly, it is safe for a user to operate. Please refer to  FIG. 7  and  FIG. 8 , the plug  2  is needed to be continually pressed inwards, the terminal  201  is pushed to press the pressing portion  533  downwards such that the contacting portion  532  is uplifted to be electrically connected with the second electrode  34 . At this time, the terminal  201  is electrically connected with the safety socket  1 . Because the terminal  201  of the plug  2  exposed outside is so short that it is not easy to happen accidents. Therefore the safety socket  1  is capable of preventing from electric shock effectively. 
   As described above, the pressing portion  533  is pressed downwardly by the terminal  201  so that the contacting portion  532  is uplifted to connect with the second electrode  34  electrically. Namely, the safety socket  1  can be connected with the plug  2  electrically only if the terminal  201  is fully inserted into the safety socket  1 . Thus the terminal  201  is not electrified before pressing the pressing portion  533 , which effectively prevents electric shock during the insertion or extraction of the plug  2  and has better performance of safety. Furthermore, because this safety socket  1  dose not require accessorial elements or other operations to achieve such function, the safety socket  1  is more convenient for the user to operate. 
   The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.