Patent Publication Number: US-9407042-B2

Title: Electrical outlet safety device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on and claims domestic priority benefits under 35 USC §119(e) from U.S. Provisional Patent Application Ser. No. 61/961,828 filed on Oct. 18, 2013, the entire content of which is expressly incorporated hereinto by reference. 
    
    
     FIELD 
     The embodiments disclosed herein relate generally to safety devices for electrical outlets. More specifically, the embodiments disclosed herein relate to devices whereby plugs associated with electrical appliances are positionally locked in an operative engaged relationship with an electrical outlet (e.g., so as to prevent removal of the plug and exposure of its associated receptacle). 
     BACKGROUND 
     Conventional electrical outlets present a known in-home hazard to children. In order to prevent potentially fatal accidental electrocution due to children inserting fingers or electrically conductive objects into an energized receptacle of the outlet, various safety device proposals intended to “child proof” electrical outlets have been advanced. One of the most common means of preventing accidental electrocution is to insert a so-called dummy plug into unused receptacles of the outlet. Such dummy plugs are usually a plate-like structure formed of an electrically insulating plastics material having a pair of protruding electrically insulating blades that may be inserted into and frictionally engaged with the contacts within the receptacle. See in this regard, U.S. Pat. No. 6,674,003 and Des, 151,571, the entire contents of which are expressly incorporated hereinto by reference. 
     While dummy plugs are useful to prevent accidental electrocution for receptacles of the outlet that are not being used to power an electrical appliance, there still exists the possibility that a child may physically remove a plug associated with an electrical appliance (e.g., by pulling on the cord to which the plug is operatively connected at its terminal end) from its engagement with a receptacle thereby exposing the receptacle (and its attendant danger) to the child. 
     What has been needed therefore are means by which the plug associated with an appliance cord may be securely positionally locked in its engaged position with a receptacle of an electrical outlet. It is towards providing such means that the embodiments disclosed herein are directed. 
     SUMMARY 
     In general, the embodiments disclosed herein are directed toward electrical outlet safety devices adapted for positionally capturing a plug head associated with an appliance cord relative to a receptacle of the outlet. Certain embodiments of the invention will include a body plate having front and rear sides and opposed lateral edges, the body plate being adapted for removable connection relative to a cover plate associated with the electrical outlet. At least one elongate open-ended blind channel will extend from one toward another of the opposed lateral edges. The channel thus defines an opposed pair of parallel edges to sandwich the plug head associated with the electrical appliance between the body plate and the cover plate of the electrical outlet, whereby the plug head is positionally captured relative to the receptacle. 
     The safety device may be embodied with a body plate having a generally E-shaped structure comprising upper and lower elongate open-ended blind channels each extending from one toward another of the opposed lateral edges. The rear side of the body plate may thus include upper and lower cavities co-located in alignment with the upper and lower channels, respectively. 
     Each of the cavities may be substantially rectangular. In certain embodiments, the cavities are asymmetrically positioned relative to horizontal centerlines of the upper and lower channels, respectively, in which case the cavities may have an upper portion which is smaller than a lower portion thereof. In use, the channels and cavities are adapted to positionally capture a plug head associated with an appliance cord relative to the receptacle of the outlet in which it is inserted. 
     The rear side of body plate may also include upper and lower recessed surfaces co-located with the upper and lower channels. Each of the upper and lower recessed surfaces may be arcuate. The depth of the upper and lower recessed surfaces may be less than the depth of the upper and lower cavities, respectively. In use, the co-located recessed arcuate surfaces are adapted to capture a conventional dummy plug if inserted into an unused one of the receptacles associated with the outlet. 
     These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof. 
    
    
     
       BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS 
       The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which: 
         FIG. 1  is a perspective view showing an outlet safety device according to an embodiment of the invention described herein positioned in operative engagement with a plug associated with an electrical cord of an appliance inserted into a receptacle of an electrical outlet; 
         FIG. 2  is an exploded perspective view of the outlet safety device shown in  FIG. 1 ; 
         FIG. 3  is a front perspective view of an outlet safety device in accordance with an embodiment of the invention described herein; 
         FIG. 4  is a left rear perspective view thereof; 
         FIG. 5  is a right rear perspective view thereof; 
         FIG. 6  is a front plan view thereof; 
         FIG. 7  is a rear plan view thereof; 
         FIG. 8  is a right side elevational view thereof; 
         FIG. 9  is a left side elevational view thereof; 
         FIG. 10  is a bottom plan view thereof, the top plan view being substantially a mirror image thereof; and 
         FIG. 11  is an exploded perspective view depicting another embodiment of an outlet safety device according to the invention described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Accompanying  FIGS. 1 and 2  depict assembled and exploded perspective views, respectively, showing an outlet safety device  10  according to an embodiment of the invention described herein positioned in operative engagement with a plug  12  associated with an electrical cord  12   a  of an appliance (not shown) inserted into a lower receptacle  14   b  of an electrical outlet  14 . The plug  12  is of a conventional variety having a pair of outwardly protruding electrically conductive blades  12 - 1 ,  12 - 2  electrically connected to the electrical wiring associated with the cord  12   a . The electrically conductive components of the plug  12  are housed within an electrically insulating plug head  12 - 3  typically formed of an elastomeric plastics material having a peripheral flange  12 - 4  providing a stop surface to prevent over insertion of the blades  12 - 1 ,  12 - 2  into the receptacle  14   b . According to preferred embodiments, the plug  12  is an ungrounded two-blade power plug adapted for use with conventional NEMA (US National Electrical Manufacturers Association) receptacles, for example, NEMA 1, NEMA 2 and/or NEMA 5 receptacles. 
     The upper receptacle  14   a  of the electrical outlet  14  which is unoccupied by an appliance plug may be child-proofed by means of a conventional dummy plug  16  having dummy blades  16 - 1 ,  16 - 2  inserted therein. 
     As used herein, the term “appliance” is intended to reference any electrical device having an electrical cord with a male plug (i.e., having at least two protruding electrically conductive blades) that may be removably engaged with the corresponding slots associated with a conventional electrical receptacle. Thus, the term “appliance” is meant to refer to computers and computer peripheral equipment such as scanners, printers, and the like, lamps, televisions, radios, vacuum cleaners, clocks and the like. 
     The outlet safety device  10  is secured to the receptacle  14  by a threaded attachment screw  18  passing through an aperture  18   a  of the device  10  and a coaxially aligned aperture  14   c  associated with the receptacle cover plate  14   d  (see  FIG. 2 ). The threaded attachment screw  18  is of sufficient length so as to engage with the internal threads of a conventional retaining aperture (not shown) associated with the receptacle  14  for the purpose of attaching the cover plate  14   d  securely thereto. Alternatively, however, a quick-release detent  15  may be provided in lieu of the screw  18  so allow the safety device  10  to be removed from the receptacle  14 . Virtually any type of quick release detent  15  may be employed so as to frictionally engage the threaded aperture of the receptacle  14  yet be capable of being withdrawn therefrom. 
     As is perhaps better shown in  FIGS. 6-10 , the safety device  10  according to the embodiment depicted is generally an E-shaped plate-like body structure having substantially planar front and rear sides  10   a ,  10   b , respectively. The safety device  10  is most preferably formed of a substantially rigid electrically insulating material (e.g., a thermoplastics material, fiberboard material or the like). Upper and lower parallel open-ended blind channels  20 ,  22  extending from one lateral side  10 - 1  toward an opposite lateral side  10 - 2  thereof. The channels  20 ,  22  are thereby defined by upper edges  20   a ,  22   a  opposed to lower parallel edges  20   b ,  22   b  and terminates beyond the vertical centerline (C V ) passing through the aperture  18   a  of the device  10  in substantially vertical interior edge  20   c ,  22   c . The channels  20 ,  22  thereby define essentially upper, intermediate and lower finger projections  11   a ,  11   b  and  11   c  extending parallel to one another and connected to a lateral bridge member  11   d.    
     The rear side  10   b  defines a pair of substantially rectangular cavities  24 ,  26  co-located in alignment with each of the channels  20 ,  22 , respectively. As is shown, the cavities  24 ,  26  may be asymmetrically positioned in their lengthwise horizontal direction) relative to a horizontal centerline C U , C L  of the respectively associated blind channels  20 ,  22 . In such a manner, therefore, upper portions  24   a ,  26   a  of each cavity  24 ,  26  are smaller than the respective lower portions  24   b ,  26   b  thereof (see  FIG. 7 ). 
     In addition to the cavities  24 ,  26 , the rear side  10   b  of the safety device  10  will likewise include co-located pairs of opposed arcuate recessed surfaces  28   a ,  28   b  and  30   a ,  30   b , respectively. The recessed surfaces  28   a ,  28   b  and  30   a ,  30   b  circumscribe the generatrices of a circle having a center co-located with a respective centerline C U , C L  of its associated blind channel  20 ,  22 . The circle circumscribed by the recessed surfaces  28   a ,  28   b  and  30   a ,  30   b  may be of substantially the same diameter or may be of a different diameter as compared to one another. In the embodiment shown in the accompanying FIGURES, the arcuate recessed surfaces  28   a ,  28   b  circumscribe a circle having a greater diameter as compared to the diameter of the circle circumscribed by recessed surfaces  30   a ,  30   b . In such a manner, the recessed surfaces  28   a ,  28   b  and  30   a ,  30   b  may accept therein a correspondingly sized dummy plug  16 . The depth of the recessed surfaces  28   a ,  28   b  is also preferably less than the depth of the cavities  24 ,  26  so that the latter provides a step-down surface relative to the former. 
     In use, the plug  12  associated with the appliance cord  12   a  may be plugged into one of the receptacles  14   a ,  14   b  associated with the electrical outlet  14  with the dummy plug  16  inserted into the other unused one of the receptacles  14   a ,  14   b . As an example depicted in  FIG. 1 , the dummy plug  16  is inserted into the upper receptacle  14   a  while the plug  12  is inserted into the lower receptacle  14   b  of the outlet  14 . 
     In order to positionally lock and secure the plug  12  relative to the receptacle  14   b , the screw  18  is removed from the outlet  14 . The safety device may then be positioned so that the flange  12 - 4  of the plug head  12 - 3  is received within the cavity  26  while the dummy plug  16  is received within the recessed surfaces  28   a ,  28   b . Positioning of the safety device  10  may conveniently be accomplished by sliding the device  10  in a lateral direction (e.g., from left to right as viewed in  FIG. 1 ) so that the plug head  12 - 3  is received within the blind channel  22 . The opposed edges  20   a ,  20   b  and  22   a ,  22   b  will therefore overlap respective portions of the dummy plug  16  and the flange  12 - 4  of the plug head  12 - 3 . 
     Once the safety device is positioned as described above, the screw  18  may be inserted through the aligned apertures  20  and  14   c  of the device  10  and cover plate  14   d , respectively, and then threadably screwed into a secured position thereby securing the device  10  against the cover plate  14   d . In some instances, a longer screw  18  than that which is conventionally provided with the outlet  14  may be required. 
     In such a manner, therefore, the flange  12 - 4  of the plug head  12 - 3  as well as the dummy plug  16  are sandwiched between the device  10  and the cover plate  14   d  thereby preventing removal from the receptacles  14   a ,  14   b , respectively. If needed, a longer screw  18  may be inserted through the aligned apertures  20  and  14   c  of the device  10  and cover plate  14   d , respectively, and then threadably screwed into a secured position. Alternatively, a quick-release detent  15  may be employed in lieu of the screw  18 . 
     Accompanying  FIG. 11  depicts the device  10  as described above being used in combination with adapter plates  40 ,  50 , respectively. As shown, each of the adapter plates  40 ,  50  is a generally planar E-shaped plate formed of an electrically insulating material (e.g., a thermoplastics material, fiberboard material or the like). Each of the adapter plates has upper and lower elongate open-ended blind channels  42 ,  44  and  52 ,  54 , respectively, extending from one toward another of the opposed lateral edges thereof. Each of the blind channels  42 ,  44  and  52 ,  54  is aligned with a respective one of the channels  20 ,  22  associated with the device  10 . 
     As will be observed, the channels  42 ,  44  and  52 ,  54  of the exemplary adapter plates  40 ,  50 , respectively, are sized differently as compared to one another and to the channels  20 ,  22  of the device  10 . Thus, the widthwise dimensions of the channels  42 ,  44  and  52 ,  54  may be different as compared to one another and to the channels  20 ,  22 . These varying dimensional attributes of the channels  42 ,  44  and  52 ,  54  of the adapter plates  40 ,  50  will thereby allow the device  10  to be adapted for capturing plug heads  12 - 3  of varying sizes and/or geometries in the manner as described above. Thus, one or both of the adapter plates  40 ,  50  may be stacked behind the device  10  and collectively secured to the outlet  14  in dependence on the particular size and/or geometry of the plug head  12 - 3  that is desired to be positionally secured. Although the adapter plates  40  and  50  have been depicted as separate structures, they could be provided as an integral (“universal”) adapter plate as may be desired. Moreover, the adapter plates  40 ,  50  may be used with a device  10  as described above which is not provided with the cavities and recesses on the rear side  10   b  thereof (i.e., in which case the device  10  is a substantially planar E-shaped plate which is substantially flat on both the front and rear sides thereof). 
     It will be understood that the description provided herein is presently considered to be the most practical and preferred embodiments of the invention. Thus, the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope thereof.