Patent Publication Number: US-9899762-B2

Title: Electrical receptacle

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/153,369, filed Apr. 27, 2015, which is incorporated by reference herein as if fully set forth. 
    
    
     FIELD OF INVENTION 
     The invention relates generally to electrical receptacles, including receptacles found in electrical outlets, power strips and extension cords. The invention relates, more specifically, to electrical receptacles having improved safety features to reduce the risk of electric shock. 
     BACKGROUND 
     Electrical receptacles are necessary to supply power to electrically powered devices. Electrical receptacles, however, pose an inherent risk of electrical shock should an individual, such as a small child, contact the electrical contacts housed within. To reduce the risk of shock, electrical receptacles are provided with narrow slots for receiving the plug of an electrical appliance, so as to prevent individuals, and in particular children, from inserting body parts or objects into the receptacle. It is still possible however, for very thin or narrow objects, to be inserted into these slots, in which case the object may contact the electrical contact and transfer current to the individual, resulting in shock. Additionally, even suitable electrical plugs can sometimes result in shock when, for example, inserted partially into a receptacle if the user&#39;s skin contacts the plug blades. 
     Various mechanisms have been proposed and implemented to reduce the risk of electrical shock. For example, electrical outlet safety covers, which may consist of plastic structures that are placed over the outlet may be used. In some cases such covers include prongs that are inserted into the slots of the receptacle, to affix the cover thereon and prevent insertion of other objects. Such covers can easily be removed by small children, reintroducing the risk of electric shock. 
     Another solution, commonly known as a tamper resistant electrical outlet, involves blocking the electrical contact ports within the outlet. This prevents a single linear object from coming in contact with the electrical elements within the outlet, but does not prevent two pronged items, such as tweezers, which may be capable of applying pressure to the hot and neutral openings at the same time, from contacting the electrical contacts. 
     SUMMARY 
     The invention relates to an electrical outlet receptacle that includes a neutral side having a neutral blade opening and neutral port aligned with the neutral blade opening. The neutral port is configured to receive a neutral blade of an electrical plug. A neutral contact is aligned with the neutral port. The receptacle further includes a hot side having a hot blade opening and a hot port aligned with the hot blade opening. The hot port is configured to receive a hot blade of an electrical plug. A hot contact is aligned with the hot port. A connector bar having a neutral tab extending into the neutral side of the receptacle is located between the neutral port and the neutral contact, and a hot tab extending into the hot side of the receptacle is located between the hot port and the hot contact. The neutral tab and the hot tab are offset from each other. 
     The invention further relates to an electrical outlet receptacle including a neutral side having a neutral blade opening and neutral port aligned with the neutral blade opening. The neutral port is configured to receive a neutral blade of an electrical plug. A neutral contact is located rearward of the neutral port. The receptacle further includes a hot side having a hot blade opening and a hot port aligned with the hot blade opening. The hot port is configured to receive a hot blade of an electrical plug. A hot contact is located rearward of hot port. A neutral tab is located between the neutral port and the neutral contact at a first vertical position, and a hot tab connected to the neutral tab and located between the hot port and the hot contact at a second vertical location that is offset from the first vertical location. 
     The invention further relates to a method of supplying electricity to an electrical plug. The method includes providing an electrical outlet receptacle including a neutral side having a neutral blade opening and neutral port aligned with the neutral blade opening. The neutral port is configured to receive a neutral blade of an electrical plug. A neutral contact is aligned with the neutral port. The receptacle further includes a hot side having a hot blade opening and a hot port aligned with the hot blade opening, the hot port configured to receive a hot blade of an electrical plug. A hot contact is aligned with the hot port. A connector bar having a neutral tab extending into the neutral side of the receptacle is located between the neutral port and the neutral contact, and a hot tab extending into the hot side of the receptacle is located between the hot port and the hot contact. The neutral tab and the hot tab are offset from each other. The method further includes providing the plug, which includes a neutral blade and a hot blade, and engaging the plug with the receptacle by inserting the neutral blade into the neutral blade opening and inserting the hot blade into the hot blade opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front elevational view of an electrical outlet having a receptacle according to the invention. 
         FIG. 2  is a perspective view of a plug of an electrically powered apparatus. 
         FIG. 3  is a front elevational view of an outlet receptacle according to an embodiment of the invention, showing the alignment of the connector bar with the neutral and hot blade openings of the receptacle. 
         FIG. 4  is a cross section taken along line  4 - 4  of  FIG. 1 . 
         FIG. 5  is a cross section taken along line  5 - 5  of  FIG. 1 . 
         FIG. 6  is a cross sectional view similar to that of  FIG. 4 , but showing a plug engaged with the outlet receptacle. 
         FIG. 7  is a cross sectional view similar to that of  FIG. 5 , but showing a plug engaged with the outlet receptacle. 
         FIG. 8  is a cross sectional view similar to that of FIG. 5 , but showing a pair of tweezers engaged with the outlet receptacle. 
         FIG. 9  is a cross sectional view similar to that of  FIG. 4 , but showing a pair of tweezers engaged with the outlet receptacle. 
         FIG. 10  is a front elevational view of an outlet receptacle according to another embodiment of the invention, showing the alignment of the connector bar with the neutral and hot blade openings of the receptacle. 
         FIG. 11  is a front elevational view of an outlet receptacle according to another embodiment of the invention. 
         FIG. 12  is a cross section taken along line  4 - 4  of  FIG. 1 , showing the outlet receptacle of  FIG. 11 . 
         FIG. 13  is a cross section taken along line  5 - 5  of  FIG. 1 , showing the receptacle of  FIG. 11 . 
         FIG. 14  is a cross sectional view similar to that of  FIG. 12 , but showing a plug engaged with the outlet receptacle. 
         FIG. 15  is a cross sectional view similar to that of  FIG. 13 , but showing a plug engaged with the outlet receptacle. 
         FIG. 16  is a cross sectional view similar to that of FIG. 12 , but showing a pair of tweezers engaged with the outlet receptacle. 
         FIG. 17  is a cross sectional view similar to that of  FIG. 13 , but showing a pair of tweezers engaged with the outlet receptacle. 
         FIG. 18  is a perspective view of another embodiment of an electrical outlet according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Certain terminology is used in the foregoing description for convenience and is not intended to be limiting. Words such as “front,” “back,” “top,” and “bottom” designate directions in the drawings to which reference is made. This terminology includes the words specifically noted above, derivatives thereof, and words of similar import. Additionally, the words “a” and “one” are defined as including one or more of the referenced item unless specifically noted. The phrase “at least one of” followed by a list of two or more items, such as “A, B or C,” means any individual one of A, B or C, as well as any combination thereof. 
     The term “receptacle” or “electrical receptacle,” as used herein, shall be defined as any receptacle configured to receive the blades of an electrical plug for the transmission of electricity, and shall include receptacles found in electrical outlets, power strips and extension cords. While an electrical outlet having receptacles according to the invention is described in detail, it should be understood that the invention can be embodied in any type of electrical receptacle. 
     Referring to  FIG. 1 , an electrical outlet  10  is shown. As shown, the outlet  10  is a standard grounded duplex outlet having two receptacles  12 , which is commonly used in the U.S., though it should be understood that the invention can be applied to other types of electrical outlets as well. In some embodiments, the outlet  10  could have only a single receptacle  12 . As shown, the outlet  10  includes an upper receptacle  12 A and a lower receptacle  12 B. A wall cover  28  may be provided with openings, allowing the receptacles  12  to protrude therethrough. Each receptacle  12  is configured to receive a standard grounded plug  20  of an electrically powered apparatus. As shown, each receptacle  12  includes hot  16  and neutral blade openings  14 , which are parallel slots configured to receive the blades of an electrical plug  20 . In the illustrated embodiment, the neutral blade opening  14  is located on the left side of the receptacle  12  and is a vertically extending slot having a first length and configured to accept a neutral blade  22  of a plug  20 . The hot blade opening  16  is a vertically extending slot having a second length that may be less than the first length, and is configured to accept a hot blade  24  of the plug  20 . The receptacle  12  of the illustrated embodiment further includes a grounded contact opening  18 , located beneath the hot and neutral blade openings  14 ,  16 , having a substantially half circular shape and configured to receive a grounded prong  26  of an electrical plug  20 . In another embodiment, the grounding contact opening  18  may be omitted, and the receptacle  12  configured to accept only plugs not having a grounded prong  26 . 
     Referring to  FIGS. 3-9 , the neutral blade opening  14  is connected to a neutral prong port  40  that houses the neutral blade  22  when the plug  20  is plugged into the receptacle  12 , and the hot blade opening  16  is connected to a hot contact port  42  that houses the hot blade  24  when the plug  20  is plugged into the receptacle  12 . 
     The neutral prong port  40  and the neutral opening  14  are located on a neutral side  30  of the receptacle  12 , which is the left side in the illustrated embodiment and in standard U.S. electrical outlets, and the hot prong port  42  and the hot opening  16  are located on a hot side  32  of the receptacle  12 , which is the right side in the illustrated embodiment and in standard U.S. electrical outlets. 
     Referring to  FIGS. 4-9  the outlet  10  further comprises a hot side output contact  46  located rearward of the hot contact port  42  and a neutral side output contact  44  located rearward of the neutral contact port  40 . Hot wire  50  supplies current to  42  through the contacts  44 ,  46 , and connector wire  52 , which connects hot side output contact  46  to hot contact port  42 . Another embodiment is shown in  FIG. 18 , in which connector wire  52  is omitted, and instead connector  152 , which is formed as a sheet of stamped metal, continuous with the side bracket  180  of the outlet. Such a construction can be employed with any embodiment of the invention described herein. 
     Referring again to the embodiment of  FIGS. 4-9 , neutral contact port  40  is connected to a neutral wire  48  that returns current away from the outlet  10 . In a conventional outlet, when the plug  20  is engaged with the receptacle  12 , and the hot blade  24  draws current via hot prong port  42 , to which hot wire  50  is directly connected, and the neutral blade  22  contacts the neutral prong port  40 , to which neutral wire  48  is directly connected, to complete the circuit. In the case of a conventional electrical outlet, another conductive object having a two pronged configuration similar to that of an electrical plug  12  could be inserted into the receptacle to complete the circuit, resulting in a dangerous condition. 
     Referring to  FIGS. 3-9 , an outlet receptacle  12  according to the invention further includes a connector bar  60 . As shown, the connector bar  60  is located behind the contact openings  14 ,  16  and contact ports  40 ,  42 . The connector bar  60  has a horizontally extending neutral tab  62  and a horizontally extending hot tab  64 . As shown, the neutral tab  62  and hot tab  64  are joined by a vertically extending link  66 . As shown, the link  66  has a vertical extension, which may be, for example, substantially equal to or less than that of the neutral opening  14  or hot opening  16 . A top end  68  of the link  66  may be located vertically proximate to an upper end of the neutral opening  14 , and a bottom end  70  of the link  66  may be located vertically proximate to a lower end of the neutral opening  14 . The link  66  is positioned substantially between the neutral side  30  and the hot side  32  of the receptacle. The neutral tab  62  extends outward perpendicularly from a first end of the link  66  and into the neutral side  30  of the receptacle  12 . The first end is the bottom end  70  in the illustrated embodiment. The hot tab  64  extends outward perpendicularly from a second end of the link  66  and into the hot side  32  of the receptacle  12 . The second end is the top end  68  in the illustrated embodiment. In other embodiments, the first end could be the top end  68  and the second end could be the bottom end  70 . In another embodiment, the neutral tab  62  and the hot tab  64  could extend from different vertical locations along the length of the link  66 . In any event, the neutral tab  62  and the hot tab  64  are misaligned, i.e., vertically offset from each other. 
     As shown in  FIGS. 4-7 , the neutral side tab  62  extends to a position in alignment with, but not contacting, the neutral side output contact  44  and the hot side tab  64  extends to a position in alignment with, but not contacting, the hot side output contact  46 . 
     The connector bar  60  has a front surface  72  facing a frontward direction of the receptacle  12  and a rear surface  74  facing a rearward direction of the receptacle  12 . The front surface  72  is formed of an insulative material, such as natural rubber or plastic. The rear surface is  74  is formed of a conductive material, such as a metallic material. The connector bar  60  is of a construction that allows it to resiliently bend. It easily bends upon application of pressure, for example from the blades of an electrical plug  20 , as described in detail below, and returns to its original, substantially planar shape upon release of pressure. 
     With reference to  FIGS. 4-7 , operation of an electrical outlet receptacle  12  and connector bar  60  according to the invention will be described in detail. As shown in  FIGS. 4 and 5 , when the plug  20  is not engaged with the receptacle  12 , the connector bar  60  has a substantially planar extension, with the neutral side tab  62  in front of and aligned with the neutral side output contact  44  and the hot side tab  64  in front of and aligned with the hot side output contact  46 . The neutral side output contact  44  and the hot side output contact  46  are not in communication with each other in this configuration, so no current is transferred or supplied. As shown in  FIGS. 6 and 7 , when the plug  20  is engaged with the receptacle  12 , the neutral blade  22  contacts the neutral side tab  62  and bends the neutral side tab  62  in a rearward direction of the receptacle  12 . At the same time, the hot blade  24  contacts the hot side tab  64  and bends the hot side tab  64  in a rearward direction of the receptacle  12 . This bending brings the neutral side tab  62 , and in particular, the conductive rear surface  74  of the connector bar  60  on the neutral side tab  62  in contact with the neutral side output contact  44 . At the same time, the hot side tab  64 , and in particular, the conductive rear surface  74  of the connector bar  60  on the hot side tab  64 , is brought into contact with the hot side output contact  46 . Accordingly, the connector bar  60  brings the neutral side output contact  44  and the hot side output contact  46  in communication with each other via the conductive rear surface  74 , completing the circuit necessary for current to be supplied to an electrical apparatus associated with the plug  20 . 
     Referring to  FIGS. 8 and 9 , two scenarios are illustrated in which a narrow, two pronged object  80  is engaged with the receptacle, which could result in a dangerous condition such as shock in the case of a conventional outlet. In the illustrated embodiment, the object  80  is a set of tweezers, but it should be understood that the outlet will respond in the same manner where other similarly sized two-pronged objects are inserted into the receptacle. As shown, a first prong  84  of the object is inserted into the neutral blade opening  14  and a second prong  82  is inserted into the hot blade opening  16 . In  FIG. 8 , the object  80  is inserted at a first vertical position, near the lower edges of the neutral and hot blade openings  14 ,  16 . When this occurs, the first prong  84  may bend the neutral tab  62  to bring the conductive rear surface  74  thereon in contact with the neutral side output contact  44 . Because the neutral side tab  62  and hot side tab  64  are displaced from each other, the second prong  82  enters the hot blade opening  16  at a position below the hot side tab  64 . The hot side tab  64 , and in turn the conductive rear surface  74  thereon, does not contact the hot side output contact  46 , failing to complete the circuit and enable current to be supplied. Similarly,  FIG. 9  shows a scenario in which the object  80  is inserted at a second vertical position, near the upper edges of the neutral and hot blade openings  14 ,  16 . When this occurs, the second prong  82  may bend the hot side tab  64 , to bring the conductive rear surface  74  thereon in contact with the hot side contact  46 . Because the neutral side tab  62  and hot side tab  64  are displaced from each other, the first prong  84  enters the neutral blade opening  16  at a position above the neutral side tab  62 . The neutral side tab  62 , and in turn the rear conductive surface  74  thereon, does not contact the neutral side contact  44 , failing to compete the circuit and enable current to be supplied. 
     Another embodiment of an electrical receptacle  12  according to the invention is shown in  FIG. 10 . This embodiment is similar to that of  FIGS. 1-9 , and only the differences will be described in detail. As shown, the connector bar  60  of this embodiment has a linear, vertical extension. As shown, the connector bar  160  is located behind the contact openings  14 ,  16  and in front of the contact ports  40 ,  42 . The connector bar  160  has a neutral tab end  162 , a central link portion  160  and a hot tab end  164 , all of which are in alignment and formed as a single, unitary, and linear extending structure. The neutral tab end  162  is located proximate to a lower end of the neutral opening  14  and the hot tab end  164  is located proximate to an upper end of the hot opening  16 . In another embodiment the diagonal extension, and in turn the positioning of the neutral tab end  162  and hot tab end  164  could be reversed, such the neutral tab end  162  is located proximate to an upper end of the neutral opening  14  and the hot tab end  164  is located proximate to a lower end of the hot opening  16 . 
     Another embodiment of an electrical receptacle  12  according to the invention is shown in  FIGS. 11-18 . This embodiment is similar to the embodiment of  FIGS. 1-9 , and only the details will be described in detail. 
     Referring to  FIGS. 11-17  the outlet  10  further comprises a hot side input contact bar  96  and a neutral side input contact bar  98 . Hot wire  50  supplies current to the hot contact port  42  through a hot input bar  90 , hot side input bar contact  96 , neutral side input bar contact  98 , and connector wire  52 , which connects hot input bar  90  to the hot contact  42 , as shown in  FIG. 13 . The neutral contact port  40  is connected to a neutral wire  48  that returns current away from the receptacle  12 . When the plug  20  is engaged with the receptacle  12 , as shown in  FIGS. 14 and 15 , the hot blade  24  contacts a hot side line  100 , and the neutral blade  22  contacts a neutral side line  102 . 
     Referring to  FIGS. 11-17  an outlet receptacle  12  according to the invention further includes a hot side slider  92 , fixedly connected to hot line  100 , and a neutral side slider  94  fixedly connected to neutral line  102 . As shown, hot line  100  and neutral line  102  are located rearward of the contact openings  14 ,  16  and ports  40 ,  42 . The slider contact bars  96 ,  98  are each fixedly associated with a slider  92 ,  94 . Slider contact bars  96 ,  98  are held in constant tension away from the hot input bar  90  by springs  104  and  106 . The neutral line  102  and the hot line  100  are aligned with and vertically offset from each other, as shown in  FIGS. 11 and 12 . The neutral line  102  extends to a position in alignment with neutral blade opening  14  and the hot line  100  extends to a position in alignment with hot blade opening  16 . In the illustrated embodiment, the hot line  100  is vertically aligned with an upper portion of hot blade opening  16  and the neutral line  100  is vertically aligned with a lower portion of the neutral blade opening  14 . In other embodiments this positioning could be reversed, such that the neutral line  100  is vertically aligned with an upper portion of the neutral blade opening  14  and the hot line  102  is vertically aligned with a lower portion of the hot blade opening. In other embodiments, the neutral and hot lines  100 ,  102  could be located at other vertical positions out of alignment with each other. 
     As shown in  FIG. 11 , the neutral side slider  94  extends to a position in horizontal alignment with, but not contacting, the hot input bar  90  and the hot side slider  92  extends to a position in horizontal alignment with, but not contacting, the hot input bar  90 . 
     The sliders  92  and  94  each have a body formed from an insulative material, such as plastic. Hot and neutral side input contact bars  96 , and  98  are each formed of a strip of conductive material, such as a metallic material. The lines  100 , and  102  are each formed of a non-conductive material and of a construction that allows for easy bending while remaining resilient to fraying. Each of the lines is sufficiently resilient so as to bend upon application of pressure, for example by the blades of an electrical plug, as shown in  FIGS. 15 and 16  and described in detail below, and to return to its original, substantially planar shape upon release of pressure, as shown in  FIGS. 12 and 13 . 
     With reference to  FIGS. 12-15 , operation of an electrical outlet receptacle  12  according to this embodiment of the invention will be described in detail. As shown in  FIGS. 12 and 13 , when the plug  20  is not engaged with the receptacle  12 , the lines  100 ,  102  each have a substantially linear extension. The contact bars  96 ,  98  are not in communication with the hot input bar  90  in this configuration, so no current is transferred or supplied. As shown in  FIGS. 14 and 15 , when the plug  20  is engaged with the receptacle  12 , the neutral blade  22  contacts the neutral side line  102 , bending the neutral side line  102  in a rearward direction of the receptacle  12  and pulling the neutral side slider  94  outward in the direction of the neutral side  30  of the receptacle  12 . At the same time, the hot blade  24  contacts the hot side line  100 , bending the hot side line  100  in a rearward direction of the receptacle  12  and pulling the hot side slider  92  outward in the direction of the hot side  32  of the receptacle  12 . This pulling brings the neutral side slider  94 , and in turn the neutral side input contact bar  98 , into contact with the hot input bar  90 . At the same time, the hot side slider  92 , and in turn, the hot side input contact bar  96 , are brought into contact with the hot input bar  90 . Accordingly, the hot input bar  90  brings the neutral side contact bar  98  and the hot side input contact bar  96  in communication with each other, completing the circuit necessary for current to be supplied to an electrical apparatus associated with the plug  20 . 
     Referring to  FIGS. 16 and 17 , two scenarios are illustrated in which a narrow, two pronged object  80  is engaged with the receptacle, which could result in a dangerous condition such as shock in the case of a conventional outlet. In the illustrated embodiment, the object  80  is a set of tweezers, but it should be understood that the outlet will respond in the same manner where other similarly sized two-pronged objects are inserted into the receptacle. As shown, a first prong  84  of the object is inserted into the neutral blade opening  14  and a second prong  82  is inserted into the hot blade opening  16 . In  FIG. 16 , the object  80  is inserted at a first vertical position, near the lower edges of the neutral and hot blade openings  14 ,  16 . When this occurs, the first prong  84  may bend the neutral line  102  to bring the slider  94  and slider contact bar  98  into contact with hot input bar  90 . Because the neutral side line  102  and hot side line  100  are vertically displaced from each other, the second prong  82  enters the hot blade opening  16  at a position below the hot side line  100 . The hot side line  100  does not bend, and in turn the hot side slider  92  remains fixed and the hot side contact bar  96  remains out of contact with the hot input bar  90 , failing to complete the circuit and enable current to be supplied. Similarly,  FIG. 17  shows a scenario in which the object  80  is inserted at a second vertical position, near the upper edges of the neutral and hot blade openings  14 ,  16 . When this occurs, the first prong  82  may bend the hot side line  100  to bring the slider  92  and slider contact bar  96  into contact with hot input bar  90 . Because the hot side line  100  and neutral side line  102  are displaced from each other, the second prong  84  enters the neutral blade opening  14  at a position above the neutral side line  102 . The neutral side line  102  does not bend, and in turn the neutral side slider  94  remains out of contact with the hot input bar  90 , failing to complete the circuit and enable current to be supplied 
     While the preferred embodiments of the invention have been described in detail above, the invention is not limited to the specific embodiments described, which should be considered as merely exemplary.