Patent Publication Number: US-8968015-B2

Title: Safety socket

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a socket, and more particularly, to a safety socket which can prevent a plug from being disengaged from the socket by accident. 
     2. Description of the Prior Art 
     A conventional safety socket uses a restraint mechanism to prevent a plug from being disengaged from the socket by accident. The restraint mechanism has a through hole. The wall of the through hole has acute corners at two open ends thereof. The conductive pins of the plug are made of a conductive metal. The conductive pins of the plug may be scraped by the two acute corners at the two open ends of the wall of the through hole when inserted in or pulled out of the through holes to cause so some metallic bits and pieces. After a period of time, a bad contact may happen to result in sparking to start a wire fire. It is necessary to improve the plug to be plugged in the socket securely. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve this problem. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a safety socket which can prevent the conductive pins of a plug from being scraped and damaged by a restraint mechanism when inserted in or pulled out of the socket. 
     In order to achieve the aforesaid object, the safety socket of the present invention comprises a main body, a restraint mechanism and a release mechanism. 
     The main body has an end surface. The end surface of the main body is formed with a plurality of insertion holes for insertion of a plurality of conductive pins of a plug. 
     The restraint mechanism comprises an immovable end and a movable end. The immovable end is disposed in the main body. The movable end is disposed at one end of the immovable end. The movable end has a through hole. The through hole corresponds in position to one of the insertion holes. The movable end has an annular protruding portion axially extending from the wall of the through hole. The annular protruding portion has a free end which is curved outward. 
     The release mechanism is movably connected to the main body and brings the movable end of the restraint mechanism to switch to an engaging position or a release position. The movable end of the restraint mechanism tends to move to the engaging position at any time. When the movable end of the restraint mechanism is located at the engaging position, one of the conductive pins of the plug is restrained by the movable end of the restraint mechanism so that the plug is unable to disengage from the main body by accident. When the movable end of the restraint mechanism is located at the release position, the conductive pins of the plug are able to be inserted in or pulled out of the insertion holes. 
     Accordingly, the safety socket of the present invention uses the restraint mechanism to prevent disengagement of the plug so as to avoid power failure of the machine connected with the plug to prevent any accident. Secondly, the wall of the through hole has arc corners (namely, the free end of the annular protruding portion) at two open ends thereof. When the movable end of the restraint mechanism is located at the release position, one of the conductive pins of the plug can be inserted in or pulled out of the through hole smoothly. The outer surface of the conductive pin won&#39;t be scraped and damaged by the wall of the through hole to enhance the service life and safety of the plug. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view according to a first embodiment of the present invention; 
         FIG. 2  is a perspective view showing the restraint mechanism coupled to the main body according to the first embodiment of the present invention; 
         FIG. 3  is a sectional view showing the plug restrained by the restraint mechanism according to the first embodiment of the present invention; 
         FIG. 3A  is an enlarged view of  FIG. 3 ; 
         FIG. 4  is a sectional view showing the plug released by the restraint mechanism according to the first embodiment of the present invention; 
         FIG. 5  is an exploded view according to a second embodiment of the present invention; 
         FIG. 5A  is a perspective view showing the inner casing according to the second embodiment of the present invention; 
         FIG. 6  is a sectional view showing the plug restrained by the restraint mechanism according to the second embodiment of the present invention; 
         FIG. 7  is a sectional view showing the plug released by the restraint mechanism according to the second embodiment of the present invention; and 
         FIG. 8  is a schematic view showing the second embodiment of the present invention installed to a system machine. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. 
     As shown in  FIG. 1  to  FIG. 4 , the safety socket according to a first embodiment of the present invention comprises a main body  10 , a restraint mechanism  20  and a release mechanism  30 . 
     The main body  10  has an end surface  11  at one end thereof and an electric wire which is integrally formed with another end of the main body  10 . This embodiment is a wire socket. The end surface  11  is provided with a plurality of insertion posts  13 . In general, there are two or three insertion poles  13 . This embodiment has three posts  13  as an example. Each post  13  has an insertion hole  12  and a conductive plate  121  in the insertion hole  12 . The insertion holes  12  are adapted for insertion of a plurality of conductive pins  41  of a plug  40 . The insertion posts  13  have a cylinder shape and the insertion holes  12  also have a cylinder shape for insertion of cylindrical conductive pins of the plug. The shape of the insertion posts  13  is designed to conform to the shape of the conductive pins  41 , not limited to the aforesaid. Preferably, the middle insertion post  13  has an engaging slot (not shown) at a bottom side thereof. The other two posts  13  each have a positioning slot  14  at an inner side thereof. 
     The restraint mechanism  20  comprises an immovable end  21  and a movable end  22 . The immovable end  21  is disposed in the main body  10 . The immovable end  21  is provided with an inlay block  211  and two insertion sheets  212 . The two insertion sheets  212  are located at two sides of the immovable end  21 . The inlay block  211  of the immovable end  21  is engaged in the engaging slot. The two insertion sheets  212  are inserted in the two positioning slots  14 . The immovable end  21  is inserted and fixed to the bottom side of the middle insertion pole  13 . The movable end  22  is disposed at one end of the immovable end  21 . The junction of the movable end  22  and the immovable end  21  is curved so the restraint mechanism  20  has an L-like shape. The movable end  22  has a through hole  221 . The through hole  221  corresponds in position to the insertion hole  12  of the middle insertion pole  13 . In this embodiment, the through hole  221  is a circular hole. The movable end  22  has an annular protruding portion  2211  axially extending from the wall of the through hole  221 . Preferably, the movable end  22  comprises an inner side  222  and an outer side  223 . The inner side  222  of the movable end  22  faces the end surface  11  of the main body  10 . To make definite, the inner side  222  of the movable end  22  is more close to the end surface  11  of the main body  10  than the outer side  223  of the movable end  22 . The annular protruding portion  2211  is close to the inner side  222  of the movable end  22  and axially extends toward the end surface  11  of the main body  10 . The annular protruding portion  2211  has a free end which is curved outward. The wall of the through hole  221  and the outer side  223  of the movable end  22  form an intersection angle  2212  which is an arc angle. In other words, the wall of the through hole  221  has arc corners at two open ends thereof. In other embodiments, the annular protruding portion  2211  is close to the outer side  223  of the movable end  22  and axially extends far away the end surface  11  of the main body  10 . The wall of the through hole  221  and the inner side  222  of the movable end  22  form an intersection angle  2212  which is an arc angle. 
     The release mechanism  30  is movably connected to the main body  10  and brings the movable end  22  of the restraint mechanism  20  to switch to an engaging position or a release position. The movable end  22  of the restraint mechanism  20  tends to move to the engaging position at any time. In this embodiment, the release mechanism  30  is a cover. The cover has a trough  31  at one end thereof and a closed surface  32  at another end thereof. The closed surface  32  is formed with a plurality of holes  321  corresponding to the insertion holes  12 . The holes  321  communicate with the trough  31 . The main body  10  is inserted in the trough  31 , as shown in  FIG. 1 . 
     As shown in  FIG. 1  to  FIG. 4 , the restraint mechanism  20  is protected by the release mechanism  30 . The hole  221  corresponds to the middle hole  321 . A distance is defined between the closed surface  32  and the end surface  11  of the main body  10  to form a movement area  50 . 
     When the conductive pins  41  are plugged in the main body  10 , the release mechanism  30  will be moved rearward toward the main body  10 . The closed surface  32  is to press the movable end  22  of the restraint mechanism  20  to close the movement area  50 . The holes  321  are aligned to the through hole  22  and the insertion holes  12  so that the conductive pins  41  of the plug  40  can be inserted in the insertion holes  12  smoothly. The conductive pins  41  of the plug  40  are contact with the conductive plates  121  of the main body  10  for electricity conduction. The release mechanism  30  is released, and the closed surface  32  disengages from the movable end  22 . The movable end  22  is returned by its elasticity to an inclined state to form the movement area  50  relative to the end surface  11 , so that the closed surface  32  and the end surface  11  are kept a distance therebetween. At this time, the movable end  22  of the restraint mechanism  20  is located at the engaging position. One of the conductive pins  41  of the plug  40  is restrained by the movable end  22  of the restraint mechanism  20 , so that the plug  40  cannot be disengaged from the main body  10  by accident, as shown in  FIG. 3  and  FIG. 3A . 
     Referring to  FIG. 4 , when the user wants to unplug the plug  41  from the present invention, the release mechanism  30  is pressed to press the movable end  22  to close the movement area  50 , as shown in  FIG. 3 . The holes  321  are aligned to the through hole  22  and the insertion holes  12 . At this time, the movable end  22  of the restraint mechanism  20  is located at the release position so that the conductive pins  41  of the plug  40  can be disengaged from the insertion holes  12  and the conductive plates  121  to pull out the plug. 
     Referring to  FIG. 5  to  FIG. 8 , a second embodiment of the present invention is substantially similar to the first embodiment with the exceptions described hereinafter. The main body  10 ′ is a normal socket, without the electric wire. The end surface  11 ′ of the main body  10 ′ doesn&#39;t have the insertion posts  13 . The end surface  11 ′ of the main body  10 ′ is formed with a plurality of insertion holes  12 ′. The through hole  221  of the movable end  22  is a rectangular hole. Preferably, the main body  10 ′ is composed an outer casing  15  having a panel and an inner casing  16 . The outer casing  15  and the inner casing  16  are assembled. Furthermore, the release mechanism comprises a button  33  and a link rod  34 . The button  33  vertically protrudes out of the end surface for the user to press thereon. When the button  33  is pressed, the link rod  34  will be moved. The link rod  34  hooks the free end of the movable end  22 , such that the link rod  34  is moved to bring the movable end  22  and the restraint mechanism is switched to the release position. Preferably, the button  33  and the link rod  34  are slidably counted to in the main body  10 ′. The release mechanism  20  defines a slide direction. The slide direction is perpendicular to the end surface  11 ′. Besides, the link rod  34  has a holding surface at one side thereof. In other embodiments of the present invention, the button  33  may be buckled, connected or adhered to the link rod  34  or in other way. 
     Accordingly, the safety socket of the present invention uses the restraint mechanism  20  to prevent disengagement of the plug  40  so as to avoid power failure of the machine connected with the plug  40  to prevent any accident. Secondly, the wall of the through hole  221  has arc corners at two open ends thereof. When the movable end  22  of the restraint mechanism  20  is located at the release position, one of the conductive pins  41  of the plug  40  can be inserted in or pulled out of the through hole  221  smoothly. The outer surface of the conductive pin  41  won&#39;t be scraped and damaged by the wall of the through hole  221  to enhance the service life and safety of the plug  40 . 
     Although particular embodiments of the present 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 present invention. Accordingly, the present invention is not to be limited except as by the appended claims.