Patent Publication Number: US-6988903-B1

Title: Extractable conversion plug with a safety protection means

Description:
BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to an extractable conversion plug with a safety protection means, and more particularly to an extractable conversion plug wherein a spring is installed between a moveable pillar of a slab and a latching element, inside a connection head, such that the slab can cover conduction pieces through an elastic force from an expansion of the spring, thereby preventing the conduction pieces from being exposed. 
   Upon emplacing the connection head at a base seat, gliding edges of the connection head are put into gliding slots. When the slab is stopped from keeping on moving by a stopper, the conduction pieces are exposed due to a persistent moving of the connection head, and are contacted with spring leaves of the base seat, thereby constituting a close-circuit status. In the mean time, the spring is under compression due to an offset of one end of the moveable pillar and latching element. 
   When the base seat falls off by accident, a stopping force of the slab is relieved to release a compression force from the spring, which will cause the spring to expand, so as to move the slab to cover the conduction pieces, thereby preventing a user from getting an electric shock by a careless touch. 
   (b) Description of the Prior Art 
   Referring to  FIG. 1  and  FIG. 2 , a conventional extractable conversion plug A consists of a connection head A 1  and a base seat A 2 . Upon using the plug, a raised edge A 11  of the connection head A 1  is put into a gliding slot A 21  of the base plate A 2 , so as to enable conduction pieces A 12  to be in contact with spring leaves A 22 , and a raised element A 23  is latched into a groove A 13 . 
   Referring to  FIG. 3 , when a conventional extractable conversion plug A is fixed on an outlet B, a base seat A 2  is easy to be loosened from a connection head A 1  if a latching structure between the connection head A 1  and the base seat A 2  is loosened from being kicked out by a user accidentally or after a long time of usage, at which conduction pieces A 12  are exposed outside and thus easy to cause the user to touch carelessly, and get an electric shock. 
   Accordingly, how to provide an extractable conversion plug with a safety protection means is a problem which needs to be solved by the inventor. 
   SUMMARY OF THE INVENTION 
   The primary object of the present invention is to provide an extractable conversion plug with a safety protection means. Referring to  FIG. 4  and  FIG. 5 , a plug is constituted by a connection head, a spring, a slab, a latching element, and a base seat, wherein a latching groove, gliding slots, gliding edges, a holding groove, and a screw hole are installed on the connection head, moveable edges and a moveable pillar are installed on the slab, and a gliding slot, a stopper, and spring leaves are installed on the base seat. The moveable edges and the moveable pillar of the slab are inserted into the gliding slots and the holding groove of the connection head, respectively. The spring is then inserted into the holding groove of the connection head. After that, the latching element is put into the latching groove and fixed by passing a screw through screw holes. 
   Referring to  FIG. 7 , the spring is located between the moveable pillar and the latching element of the slab, and the slab can be covered on conduction pieces through an elastic force from an expansion of the spring, so as to prevent the conduction pieces from being exposed. Upon emplacing the connection head at the base seat, the gliding edges of the connection head are emplaced into the gliding slot. On the other hand, when the slab is stopped by the stopper and cannot keep on moving, the conduction pieces will be exposed due to a persistent moving of the connection head and will be contacted with the spring leaves of the base seat, thereby constituting a close-circuit condition. In the mean time, the spring is under compression due to an offset of one end of the moveable pillar and the latching element. Therefore, when the base seat falls off by accident, a stopping force of the slab will be relieved to release a compression force of the spring, which will cause the spring to expand, so as to move the slab to cover the conduction pieces, thereby preventing a user from getting an electric shock by a careless touch. 
   To enable a further understanding of the said objectives and the technological methods of the invention herein, the brief description of the drawings below is followed by the detailed description of the preferred embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of a conventional extractable conversion plug. 
       FIG. 2  shows a rear view of a conventional connection head. 
       FIG. 3  shows a perspective view of a fall-off condition of a conventional extractable conversion plug. 
       FIG. 4  shows a perspective view of the present invention. 
       FIG. 5  shows an assembly view of the present invention. 
       FIG. 6  shows a schematic view of another side of a slab of the present invention. 
       FIG. 7  shows a cutaway view of the present invention. 
       FIG. 8  shows a cutaway view of an action of the present invention. 
       FIG. 9  shows a second cutaway view of an action of the present invention. 
       FIG. 10  shows third cutaway view of an action of the present invention. 
       FIG. 11  shows a fourth cutaway view of an action of the present invention. 
       FIG. 11A  shows a blowup view of part a of  FIG. 11 . 
       FIG. 12  shows a schematic view of a further implementation of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 8 , it shows an implementation of the present invention. Before emplacing a connection head C 1  at a base seat D, a spring C 2  is located between a moveable pillar C 32  and a latching element C 4  of a slab C 3 , so as to cover the slab C 3  on conduction pieces C 5  through an elastic force of the spring C 2 , thereby preventing the conduction pieces C 5  from being exposed. 
   Referring to  FIG. 9  and  FIG. 10 , upon emplacing the connection head C 1  at the base seat D, gliding edges C 13  is moving inside a gliding slot D 1 , and the slab C 3  is gradually approaching to a stopper D 2  of the base seat D. When the connection head C 1  keeps on moving, the stopper D 2  will stop the slab C 3  from moving further. At this time, the moveable pillar C 32  will be immoveable due to a stop of the slab C 3 , but the spring C 2  will start to be compressed due to a persistent moving of the latching element C 4  at the other end of spring C 2 . 
   When the connection head C 1  keeps on moving until completely inserting the gliding edges C 13  into the gliding slot D 1 , the conduction pieces C 5  will be exposed and contacted with spring leaves D 3  to constitute a close-circuit condition due to a persistent stop of the slab C 3 . At this time, a plug C can be connected to a socket for conducting electricity, and the spring C 2  is compressed to its maximum extent. 
   Referring to  FIG. 11  and  FIG. 11A , when the base seat D falls off by accident, the slab C 3  can be in a mobilized state due to that the stopper D 2  of the base seat D is not stopping the slab C 3 . Moreover, as the spring C 2  is turned into an expansion state from the aforementioned compression state, which completely relieves its elastic force, so as to put the moveable pillar C 32  of the slab C 3  against a top end of holding groove C 14  of the connection head C 1 , and to move the slab C 3  to cover on the conduction pieces C 5  which are exposed previously, thereby preventing a user from getting an electric shock by a careless touch. 
   In addition, when a user wants to remove the connection head C 1  from the socket B, he would not be worried about touching the conduction pieces C 5  to get an electric shock during removing, as the connection head C 1  is made of insulation material. Furthermore, if the base seat D falls off by accident, the user can directly mount the base seat D on the connection head C 1  inserted on the plug C, before taking out the plug C. 
   Referring to  FIG. 12 , a connection head of the present invention can be further mounted with conduction pieces E, E 1 , and E 2  of various sizes, quantities, and layouts, corresponding to specifications of power plugs in different countries. On the other hand, when the connection head C 1  is not connected to the base seat D, the slab C 3  can completely cover the conduction pieces E, E 1 , and E 2 . 
   To further manifest the advancement and practicability of the present invention, the present invention is compared with a conventional application as follow: 
   Shortcomings of a Conventional Application
         There is no safety shielding for conduction pieces on a connection head.   If a base seat is loosened from the connection head by accident, the conduction pieces will be completely exposed, which will be easy to cause a user to get an electric shock.       

   Advantages of the Present Invention
         Conduction pieces can be completely covered by a slab while not in use.   If a slab is loosened from a base seat by accident, the conduction pieces will be covered by the slab.   Accordingly, if the base seat falls off by accident upon connecting to a socket, the conduction pieces will be completely covered by the slab.   It can prevent a user from getting an electric shock.   It is provided with an advancement, practicability, and safety.   It can promote an industrial competitiveness.       

   It is of course to be understood that the embodiments described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.