Abstract:
An electrical connector includes a male element which has a spring-loaded lock element and a female wall socket that has a lock element-accommodating opening defined therein. The spring-loaded lock element is operated by means of a screw driver-accommodating element located on the male element.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to the general art of electrical connectors, and to the particular field of locks for electrical connectors. 
   2. Discussion of the Related Art 
   Many parents try to child-proof their homes or residences. Child-proofing often includes erecting gates, locking cabinet doors, and locking drawers. All of these steps are intended to prevent a child from injuring himself. 
   Many children are injured because they came into contact with electricity. This situation often occurs when a child places his or her finger or an object into an electrical outlet. For this reason, many parents close electrical outlets by placing plastic covers over the outlets or the like. This is effective. However, there is yet another way children can come into contact with electricity. If an electrical product is plugged into an outlet and that plug is partially removed, an open electrical connection is established and anyone contacting that open connection is in danger of receiving a serious electrical shock. 
   Therefore, there is a need for an electrical connector unit which can prevent an electrical plug from being unintentionally and partially removed from a socket. 
   Even though it is important to prevent an electrical plug from being inadvertently removed from a socket, it is also necessary to make it expeditious and easy to lock and unlock the plug and socket connection. If it is too difficult or cumbersome to lock and unlock the plug and the socket, the locking feature may not be used. 
   Therefore, there is a need for an electrical connector unit that can be locked and unlocked in an expeditious manner. 
   PRINCIPAL OBJECTS OF THE INVENTION 
   It is a main object of the present invention to provide an electrical connector unit which can prevent an electrical plug from being unintentionally and partially removed from a socket. 
   It is another object of the present invention to provide an electrical connector unit that can be locked and unlocked in an expeditious manner. 
   SUMMARY OF THE INVENTION 
   These, and other, objects are achieved by a locking unit for an electrical plug and socket combination which includes a prong on the male portion of the unit and a slot defined on the socket portion of the unit. The prong is T-shaped and is rotatably mounted on the male portion to move between a locking orientation and an unlocking orientation. When the prong is in the unlocking orientation, it can be moved through the slot defined on the socket portion, and once through the slot, the prong can be rotated into a locking orientation. When the prong is in the locking orientation, it cannot pass through the slot so the male portion will be locked to the socket portion. The male portion has electrical prongs and the socket has electrical prong-accommodating slots. When the male portion is locked to the socket, the electrical prongs are locked in the electrical prong-accommodating slots. 
   Using the locking unit embodying the present invention will permit a male portion of a plug unit to be easily and quickly locked to the socket portion of a plug unit so the plug unit is securely locked to the socket portion. However, the male portion can be quickly and easily unlocked and removed from the socket portion so use of the locking feature will be easy and expeditious. 

   
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       FIG. 1  is a perspective view of an electrical plug having a lock element embodying the present invention. 
       FIG. 2  is a rear elevational view of the electrical plug embodying the present invention. 
       FIG. 3  is a wall outlet socket which is used in conjunction with the electrical plug shown in  FIG. 1 . 
       FIG. 4  is a perspective view of a barrel portion of a lock element which is included in the electrical plug embodying the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description and the accompanying drawings. 
   Referring to the Figures, it can be understood that the present invention is embodied in an electrical connector unit  10  that will be easy and expeditious to use and will securely lock a plug into a socket, such as a wall outlet. 
   The electrical connector unit  10  embodying the present invention comprises a male element  12  such as might be associated with an electrically powered element. 
   Male element  12  includes a housing  14  having a first surface  16 , which is a front surface when male element  12  is in use, and a second surface  18 , which is a rear surface when male element  12  is in use. 
   A grounding prong  20  extends outwardly from the first surface  16 , and two electrical contact prongs  22  and  24  extend outwardly from first surface  16 . 
   An electrical cord  26  is electrically connected to electrical contact prongs  22  and  24  in the manner common to such plugs. 
   The unit  10  embodying the present invention further includes a lock element prong-accommodating orifice  30  defined in first surface  16 . 
   A lock element  36  includes a prong  38  which extends outwardly from first surface  16  through lock element-accommodating orifice  30 . Prong  38  includes a body  40 , which has a proximal end  42  located inside housing  14 , and a distal end  44 , which is located outside housing  14 . A head element  50  is located on body  40 . Head element  50  is oriented at a right angle to body  40  and is spaced apart from first surface  16 . Head element  50  is oriented with respect to body  40  to define a T-shape. 
   A prong-operating system  60  is located in housing  14  and includes a barrel  62  rotatably mounted on housing  14 . Barrel  62  has an operating surface  64  located on second surface  18  of housing  14 . A slot  66  is defined in operating surface  64 , and is adapted to accommodate a blade of a screwdriver or the like. 
   Barrel  62  has a second surface  68  connected to proximal end  42  of prong  40  in housing  14 . 
   Barrel  62  further includes a longitudinal axis  72  which extends between operating surface  64  and second surface  68  of barrel  62 . Longitudinal axis  72  of barrel  62  also extends between first surface  16  of housing  14  and second surface  18  of housing  14 . 
   Barrel  62  is mounted in housing  14  for rotation about longitudinal axis  72  as indicated by double-headed arrow  76  in  FIG. 4 . Prong  38  rotates with barrel  62  so head element  50  moves between an unlocking orientation indicated in  FIG. 4  by solid lines  50 U and a locking orientation indicated in  FIG. 4  by dotted lines  50 L. 
   A female receptacle  80  is shown in  FIG. 3  and can be mounted on a wall or the like. 
   Female receptacle or socket element  80  includes a face plate  82  and two electrical prong-accommodating slots  84  and  86  defined through the face plate  82 . An electrical connection  88  is electrically connected to electrical prong-accommodating slots  84  and  86 . 
   A lock element-accommodating receptacle  90  is defined in the face plate  82 . Lock element-accommodating receptacle  90  includes a slot  92  defined through face plate  82 . Slot  92  is sized and oriented to accommodate head element  50  of prong  38  when the head element  50  of prong  40  is in unlocking orientation  50 U to permit head element  50  to move through slot  92 . Slot  92  is also sized and oriented to prevent head element  50  from passing through slot  92  when the head element  50  of prong  40  is in locking orientation  50 L. 
   Slot  92  defined through face plate  82  is located adjacent to electrical prong-accommodating slots  84  and  86  so that when prong  40  is accommodated through slot  92 , electrical contact prongs  22  and  24  are accommodated in electrical prong-accommodating slots  84  and  86 . 
   A grounding prong-accommodating orifice  100  is located on face plate  82  and accommodates grounding prong  20  of male element  12  for the usual purpose of grounding the connection. 
   As shown in  FIG. 4 , springs  110  and  112  can be interposed between second surface  68  of barrel  62  and first surface  16  of housing  14  to bias the barrel  62  in direction  114  towards second surface  18 . Operating surface  64  is positioned inside housing  14  and abuts the inside of surface  18  to prevent barrel  62  from moving out of housing  14  under the influence of springs  110  and  112 . Operation of the barrel  62  will require a user to press inwardly on operating surface  64  via slot  66  to move prong  40  through slot  92 . Once pressure is released, springs  110  and  112  draw head element  50  back against face plate  82  so head element  50  abuts face plate  82  adjacent to slot  92 . This abutting contact will ensure stable locking of male element  12  to socket element  80 . 
   Operation of the electrical connector unit can be understood by those skilled in the art based on the teaching of the present disclosure and thus will not be described in detail. Male element  12  is oriented adjacent to socket element  80  and barrel  62  is rotated by means of a screwdriver blade being inserted into slot  66  and rotated so head element  50  is in unlocking orientation  50 U. Male element  12  is then moved toward socket element  80  so that electrical prongs  22  and  24 , and grounding prong  20 , are moved into prong-accommodating orifices  84 ,  86  and  100 . After the prongs are securely in the prong-accommodating orifices and prong  40  extends through slot  92 , barrel  62  is again rotated so head element  50  moves into locking orientation  50 L and abuts face plate  82  adjacent to slot  92 . The male element  12  is then locked to the face plate  82  and the prongs cannot be moved out of the prong-accommodating holes. The plug is thus locked to the socket. Release of the plug from the socket is the reverse of the aforedescribed process where head element  50  is rotated into unlocking orientation  50 U, and male element  12  is pulled away from socket element  80 . 
   It is understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangements of parts described and shown.