Abstract:
A retractable power plug applied for an electronic apparatus or an extension outlet is disclosed. The retractable power plug includes a housing, a base, a movable unit and a plurality of prongs. The housing has a space for enclosing the base. The prongs are pluggably disposed on the base. The base is rotatably and movably located in the space. The movable unit is configured to prompt the base to move in the space. The direction of movement of the base is generally parallel with the connection direction of the prongs. So that, the prongs associated with the base is capable of moving up and down in the space.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a power plug, in particular, to a power plug with retractable prongs. 
         [0003]    2. Description of Related Art 
         [0004]    Responsive to the portability of modern electric appliances, the related designs have tendency to be thinner and light weight. Thus, any protruded prong becomes disadvantageous to pack up the portable appliances since the prong may occupy extra space. The prong may scrape the other articles, or be bent or deformed by extrusion. 
         [0005]    For this reason, it conducts a topic for the skilled person in the art to pack up the plug with prongs conveniently. 
       SUMMARY OF THE INVENTION 
       [0006]    One of the objectives of the instant disclosure is to provide a retractable power plug, which can hide the protruding prongs into the power plug. Therefore, the plug becomes more convenient to pack up and carry safely. 
         [0007]    For the above-described objective, the provided approach with respect to the retractable power plug is particularly adapted to any appliance having a plug or to the extension outlet with a plug. The retractable power plug has a housing, a base and a plurality of prongs. The housing includes a space which is used to enclose a base. The prongs are pluggably disposed on the base. In particular, the base is rotatably and movably disposed in the space. The direction of movement of the base is generally parallel with the connection direction of the prongs. Therefore, the prongs on the base may retract back or expose out freely in the space. 
         [0008]    One more aspect in the instant disclosure is regarding a retractable power plug having a housing, a base, a plurality of prongs and a movable unit. The housing also has space. The base is capable of rotatably retracting back or exposing out in the space. The prongs are separately disposed on the base. The movable unit is movably disposed in the space, and its movement jointly drives the base moving within the space. The direction of movement of the base is generally parallel with the connection direction of the prongs. The prongs can retract back or expose out along with the base, and are allowed to be enclosed within the space, or exposed out of the housing. 
         [0009]    These and other various advantages and features of the instant disclosure will become apparent from the following descriptions and claims, in conjunction with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1A through 1C  shows a schematic diagram of the first embodiment of a retractable power plug in accordance with the present invention; 
           [0011]      FIG. 2  shows a schematic diagram of the second embodiment of the retractable power plug in accordance with the present invention; 
           [0012]      FIG. 3A through 3B  schematically shows a third embodiment of the retractable power plug of the present invention; 
           [0013]      FIG. 4A  shows a schematic diagram of a first embodiment of a conductive ring of the retractable power plug in accordance with the present invention; and 
           [0014]      FIG. 4B  shows a schematic diagram of a second embodiment of the conductive ring of the retractable power plug in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]      FIG. 1A  through  FIG. 1C  schematically show the first embodiment of a retractable power plug in accordance with the present invention. In  FIG. 1A , the retractable power plug has a housing  10 , a base  11 , a plurality of prongs  13  and a rotatable element  15 . The housing  10  is connected with an electric wire  19 . Further, the housing  10  has an internal space  101  for sufficiently enclose all external conducting elements which would normally be outside the housing during use, for example, the base  11 . In particular, the ends of the conducting prongs  13  are separately pluggably disposed on the base  11 , and used to electrically connect to the electric wire  19 . Each prong is disposed one the base  11  and electrically separated from each other. In an example, the prongs  13  are electrically connected to the wire  19  through a conductive slice or a conductive ring (not shown). Further, the rotatable element  15  is pivoted with the housing  10 , in order to provide the user to control the position of the base  11  within the space  101 . Thus the base  11  moves toward the housing  10  along the connection direction of the prongs  13 . The prongs  13  therefore can be retracted within the space  101  or exposed out of the housing  10 . 
         [0016]    Furthermore, the base  11  can move within the space  101  from the surface of housing  10  to the interior of the housing  10 . The base  11  does not stop until the prongs  13  are entirely enclosed within the space  101 . 
         [0017]    In an example shown in  FIG. 1B , if the retractable power plug  1   a  is used to take power, the rotatable element  15  may drive the base  11  up to the surface of housing  10 . Such as  FIG. 1A , the retractable power plug  1   a  can be used to install on a wall-type socket, or an extension outlet (not shown). The claimed plug occupies smaller space since it can be retracted. Therefore the prongs  13  will not be exposed and make it easier to carry, and furthermore, it does not hook or scratch other articles. 
         [0018]    For specifically describing the movements of prongs  13  of the claimed retractable power plug  1   a , reference is made to  FIG. 1C  showing an explode diagram of the plug in the first embodiment. The retractable power plug  1   a  further includes a ring  17  disposed within a space  101  and between the base  11  and the rotatable element  15  in addition to the housing  10 , the base  11 , the plurality of prongs  13  and the rotatable element  15 . The ring  17  and a corresponding guiding portion  102  are inside the housing  10 . The ring  17  moves along the guiding portion  102  and within the housing  10 . In particular, the rotatable element  15  and the ring  17  are formed as a movable unit (not shown) of the retractable power plug  1   a . The movable unit jointly drives the base  11  up and down in the space  101 . 
         [0019]    In the current embodiment, a protruding portion  171  and at least one notch portion  173  are disposed outside the ring  17 . The thickness and width of the guiding portion  102  match the design of protruding portion  171  for properly guiding the protruding portion  171  moving along the guiding portion  102 . Therefore, the ring  17  can move up and down in the housing  10 . 
         [0020]    The rotatable element  15  has a push-against portion  151  which extends to the base  11 . The notch portion  173  outside the ring  17  is wedged with the push-against portion  151 . When the rotatable element  15  clockwise or counterclockwise rotates with respect to the housing  10 , the push-against portion  151  will push the protruding portion  171  to move along the guiding portion  102 . Since the ring  17  moves inward or outward relative to the sidewall of housing  10 , the ring  17  may synchronously push the upper base  11  moving inward or outward. 
         [0021]    In one embodiment, the protruding portion  171  can be one or more ring flanges or at least one screw thread. The guiding portion  102  can be designed as an impressed spiral trench corresponding to the size of the flange. Through the rotatable element  15 , the flange is allowed to move along the spiral trench. In the meanwhile, the position of the mentioned ring  17  changes along with the housing  10 . 
         [0022]    It is worth noting that the base  11  may not follow the ring  17  to moving inward or outward since the plug  1   a  is configured to prevent the electric wire  19  connected with the base  11  from damage by twisting. The outer surface of the base  11  is levelly rotatable to the housing  10 . However, the rotatable base  11  is independent of the ring  17  relative to the housing  10 . Following describes how the base  11  is rotatably disposed within the space  101 . 
         [0023]    The base  11  includes a cover plate  111 , a side plate  113 , and a bottom plate  115 . The prongs  13  are pluggably disposed on the cover plate  111 . The side plate  113  and the bottom plate  115  can be immovably combined. The electric wire  19  is soldered to or adhesive to the side plate  113  or the bottom plate  115 . The prongs  13  prop with the electric wire  19  via a conductive slice. The cover plate  111  is rotatable with respect to the side plate  113  and the bottom plate  115 , namely the prongs  13  is levelly rotatable to the housing  10 . The prongs  13  may keep contact with the electric wire  19  rather than separation. 
         [0024]    Therefore, when the retractable power plug  1   a  is plugged to a socket, the electric wire  19  connected with the side of housing  10  can be rotated with any angle. For example, the rotated angle can be 360 degree. The plug&#39;s flexibility can be enhanced since its connection direction is not restricted. 
         [0025]    According to the embodiment in accordance with the present invention, the outer appearance of the housing  10  may be any shape such as a cylinder or a polygonal cylinder. The electric wire  19  may connect with the side or bottom of the housing  10 . The rotatable element  15  may be disposed on the bottom or side of the housing  10 . The prongs  13  may be two or three prongs. In which, a first prong  131  and a second prong  133  are respectively a live contact and a neutral contact if two-prong example is introduced. Preferably, the two polarities of the first prong  131  and the second prong  133  can be exchanged. For a three-prong example, the first prong  131 , the second prong  133  and a third prong  135  are included, and the first prong  131  and the second prong  133  are respectively the live contact and the neutral contact, and the third prong  135  is an earth contact. 
         [0026]    In a first embodiment of the retractable power plug  1   a , the ring  17  of the rotatable element  15  jointly rotatable and movable is merely one of the embodiments. In practice, the ring  17  may also be levelly rotated or vertically moved. For example, the push-against portion  151  can be formed on the bottom  103 , and the housing  10  is pivoted to the bottom  103 . So that the rotatable element  15  can be omitted. Its protruding portion  171  and notch portion  173  can be formed on the base  11 . The notch portion  173  and the push-against portion  151  are entangled with each other. The guiding portion  102  on the inner wall of the housing  10  may be a spiral trench. When the housing  10  rotates clockwise or counterclockwise relative to the bottom  103 , the push-against portion  151  is used to confine the rotation of the base  11  along with the notch portion  173 . The protruding portion  171  of base  11  moves along with the guiding portion  102  on the sidewall of the housing  10 . Therefore, the base  11  may freely move inward or outward. 
         [0027]    Next reference is made to  FIG. 2  showing an explode diagram of the second embodiment of the retractable power plug. The retractable power plug  1   b  of this second embodiment is similar to the first embodiment. A ring  17 ′ is also introduced to drive the upper base  11  moving inward or outward. Rather than the first embodiment, the retractable power plug  1   b  of the second embodiment has no rotatable element  15 , but adds an elastic element  16 . The elastic element  16  and the ring  17 ′ form a movable unit of the retractable power plug  1   b . This movable unit especially drives the base  11  moving inward or outward within the space  101 . 
         [0028]    In the current embodiment, the guiding portion  102 ′ inside the housing  10  can be a plurality of long trenches. The direction of the plural long trenches is parallel with the connection direction of the prongs  13 . The long trenches especially extend up from bottom of the housing  10 ′. The trenches have two different depths, and two trenches with the two different depths are arranged alternately. The protruding portion  171 ′ outside the ring  17 ′ is formed with many bumps. The bumps correspond to the long trenches. That means the bumps can be selectively distributed over the trenches with different depths. 
         [0029]    When the bumps are simultaneously distributed over the trenches with shallower depths, the ring  17 ′ can be buried inside the space  101 , and the base  11  and the prongs  13  can be enclosed within the space  101 . When the bumps are distributed over the shallower trenches, the ring  17 ′ can be raised around the upper surface of housing  10 ′. Therefore, the base  11  may move up to the surface of housing  10 ′, and the prongs  13  can be exposed out the space  101 . 
         [0030]    The elastic element  16 , in the current embodiment, is disposed below the ring  17 ′. The elastic element  16  and the ring  17 ′ are propped with each other. The protruding portion  171 ′ of the ring  17 ′ is disposed in the deepest position of the guiding portion  102 ′, namely the bottom of the long trenches. In particular, a plurality of first one-way teeth  1031  are disposed on the upper surface of bottom  103 ′ of housing  10 ′, and a plurality of second one-way teeth  175  are at lower edge of the ring  17 ′. The position of the first one-way teeth  1031  corresponds to the position of the second one-way teeth  175 , and they can be mutually slipped. Since the ring  17 ′ is pressured from top to bottom, the ring  17 ′ can rotate relative to the housing  10 ′. With every pressure, the ring  17 ′ may rotate once, and the protruding portion  171 ′ may alternately enter the long trenches with different depths. 
         [0031]    References are made to  FIG. 3A  and  FIG. 3B . The retractable power plug in the third embodiment is similar with the plug in the second embodiment since both they use the elastic element  16  to drive the base  11 . The difference is that the retractable power plug  1   c  does not have the ring  17 ′, and the housing  10 ″ without the guiding portion  102 . The plug  1   c  particularly has a locking unit  14  disposed on a sidewall of the housing  10 ″ for user&#39;s operation. The locking unit  14  may follow the user&#39;s operation to lock or unlock the base  11  at a specific position. For example, the base  11  may be moved to a surface of housing  10 ″, or be retracted within the space  101 ′. 
         [0032]    The locking unit  14  preferably can be a rocker button, and its two ends may respectively be wedged with the cover plate  111  of base  11 . So that, the base  11  can be immovably fixed onto the surface of housing  10 ″ or be buried into the space  101 ′. In practice, the structure of the claimed plug may be modified to different embodiments. For example, the upper position of housing  10 ″ has a closed top portion formed as a cover body. The top portion of the housing  10 ″ includes a plurality of holes (not shown), and the bottom  103 ′ is combined with the base  11 . The mentioned elastic element  16  is located between the top portion of housing  10 ″ and the base  11 . 
         [0033]    When the bottom  103 ′ is pressed, the bottom  103 ′ may move with the base  11 , and the prongs  13  may expose out of the holes on the top portion of housing  10 ″. Furthermore, one end of the locking unit  14  may be wedged with the cover plate  111  of base  11  for foxing the base  11 . The elastic element  16  may be pressured into the position between the top portion of housing  10 ″ and the base  11 . The elastic element  16  may be released to push the base  11  to the original position as unlocking the locking unit  14 . Therefore, the prongs  13  may be retracted into the housing  10 ″. The top portion of the housing  10 ″ serves as a dust-proof portion. 
         [0034]    The locking unit  14  can also be modified for applying to the described first embodiment or the second embodiment. The locking unit  14  may be wedged with the ring  17  and the ring  17 ′ for fixing the base  11 . 
         [0035]    In order to clarify the horizontal rotations of the prongs  13  with respect to the described housing  10 ,  10 ′ or  10 ″, further references are made to  FIG. 4A  and  FIG. 4B , which are respectively the first and second embodiment of the conductive ring for the retractable power plug. In which, the bottom plate  115  and the side plate  113  of base  11  are immovably connected as one body. The one end of each prong  13  is immovably and pluggably disposed on the cover plate  111 . The plurality of prongs  13  and the cover plate  111  are levelly rotatable with respect to the side plate  113  and the bottom plate  115 . In the rotation, the cover plate  111  and the side plate  113  can be kept un-separable. Further, the prongs  13  and the electric wire  19  can be kept contact. As shown in  FIG. 4A , there are three concentric conductive rings  181 ,  183 , and  185  with different radiuses disposed on the bottom plate  115  of base  11   a . The three rings  181 ,  183 , and  185  are separately connected to the different polarities of the electric wire  19 . The prongs  131 ,  133 , and  135  individually have the extendable conductive members  21 ,  23 , and  25 . The conductive members  21 ,  23 , and  25  are separately propped to the corresponding conductive rings  181 ,  183 , and  185 . 
         [0036]    In particular, when the prongs  131 ,  133 , and  135  rotate with the cover plate  11   a , the conductive rings  181 ,  183 ,  185  and the bottom plate  115  may not be rotated therewith for preventing twist of the wire  19 . However, the conductive members  21 ,  23 , and  25  may rotate along with the cover plate  11 , and always keep contact with the conductive rings  181 ,  183 , and  185 . 
         [0037]    Reference is made to  FIG. 4B , the second embodiment of the conductive ring may have three conductive rings  181 ′,  183 ′, and  185 ′ with the same size. The three rings  181 ′,  183 ′, and  185 ′ are separately disposed on the inner of side plate  113  of the base  11   b . The prongs  131 ,  133 , and  135  are correspondingly propped with the conductive ring  181 ′,  183 ′, and  185 ′ via the conductive members  21 ,  23 , and  25 . Provided is the feature that the prongs  131 ,  133 , and  135  may rotate with the cover plate  11   b , and also keep contact with the conductive rings  181 ′,  183 ′, and  185 ′. 
         [0038]    In summation of the instant disclosure, the retractable power plug is provided as the prongs are configured to be rotatable or movable by a pressing means, especially the prongs are levelly rotatable and retractable for convenience. 
         [0039]    While the above description constitutes the preferred embodiment of the instant disclosure, it should be appreciated that the invention may be modified without departing from the proper scope or fair meaning of the accompanying claims. Various other advantages of the instant disclosure will become apparent to those skilled in the art after having the benefit of studying the foregoing text and drawings taken in conjunction with the following claims.