Patent Publication Number: US-2023163524-A1

Title: Tamper resistant electrical outlet

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of U.S. provisional application Ser. No. 63/282,884, filed Nov. 24, 2020, which is hereby incorporated herein by reference in its entirety 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical receptacles and, more particularly, to electrical receptacles that, typically for safety reasons, block or limit undesired access to electrical contacts that are contained within the receptacles. 
     BACKGROUND OF THE INVENTION 
     Electrical receptacles or outlets, such as 110V AC or 220V AC simplex or duplex outlets or the like, are typically designed to receive at least two or three conductive prongs of an electrical plug associated with an electrical consumer, such as an appliance. The electrical receptacles have openings that receive respective prongs of an electrical plug, and have female electrical contacts spaced behind the openings, but the receptacle openings are typically too small (and the electrical contacts spaced too far rearwardly) for children&#39;s fingers or many common household objects to be inserted. However, paperclips, small screwdrivers, nails, and many other common objects are both electrically conductive and sufficiently small to pass through the openings and come into conductive contact with the electrical contacts of a typical electrical receptacle, which presents a risk of electrical shock, particularly for children or persons unfamiliar with (or unable to fully comprehend) the risks associated with electrical outlets and contact with electrical current. 
     Many access-restricting electrical outlets have been developed which block the insertion of objects into one or more outlet openings unless appropriately-sized objects (such as two prongs of an electrical plug) are inserted simultaneously. This causes a slider or other access-blocking structure to move aside and provide access to the live electrical contacts located behind the access-blocking structure. However, access-restricting electrical outlets typically provide higher resistance to plug-insertion in order to move the access-blocking structure laterally in response to perpendicular insertion force. They can also be prone to wear from excessive use, and can be prone to damage from high insertion forces of misaligned plugs. 
     SUMMARY OF THE INVENTION 
     The present invention provides a tamper-resistant electrical outlet that limits access to live electrical contacts by maintaining those electrical contacts in a non-energized state by default. Each electrical contact is energized once a compatible object, such as a prong of a proper electrical plug, has been inserted into an outlet opening associate with a different electrical contact. For example, in an electrical outlet having line (“hot”) and neutral contacts positioned behind line (“hot”) and neutral outlet openings, the line contact is only made “live” (i.e., electrically connected to a line supply conductor) when an object (e.g., a neutral plug prong) is inserted sufficiently far into the neutral outlet opening. Likewise, the neutral contact is only made live (i.e., electrically connected to a neutral supply conductor) when an object (e.g., a line plug prong) is inserted sufficiently far into the line outlet opening. Therefore, internal structures of the tamper-resistant electrical outlet do not preclude or prevent access to the internal electrical receptacle contacts, but instead provide enhanced safety by maintaining each electrical contact in a non-energized state until an object is inserted sufficiently far into a different electrical contact&#39;s opening. The tamper-resistant electrical outlet does not rely on access-blocking structures, but instead relies on selective energizing of the electrical contacts to provide enhanced electrical safety. The resulting outlet thus operates in a manner that is substantially indistinguishable from a conventional electrical outlet, and is not as susceptible to wear or damage from high insertion forces as is a typical access-restricting electrical outlet. 
     According to one form of the present invention, a tamper resistant electrical outlet includes a receptacle body with first and second receptacle contacts mounted therein, behind first and second outlet openings in a face of the body. First and second live contacts are also mounted in the receptacle body, and are designed to be continuously energized by respective conductors, such as wires from an electrical mains source. First and second actuators are mounted in the receptacle body and are configured to selectively and independently urge respective live contacts toward respective receptacle contacts in order to establish an electrical connection from the live conductors and contacts to the receptacle contacts. The live contacts are movable with respect to the receptacle contacts, and in a default position the live contacts are spaced apart from the receptacle contacts. The first live contact is configured to engage and electrically energize the first receptacle contact in response to insertion of an object through the second outlet opening in a manner that engages and moves the first actuator. The second live contact is configured to engage and electrically energize the second receptacle contact in response to insertion of an object through the first outlet opening in a manner that engages and moves the second actuator. 
     Thus, the tamper resistant electrical outlet of the present invention restricts access to live electrical contacts by maintaining the electrical contacts in a non-energized state by default, and only energizing a given contact once an object is inserted sufficiently far into a different contact&#39;s opening. Inserting a small conductive object such as a paperclip or a small screwdriver into a first outlet opening and into engagement with an associated first electrical contact, will not by itself cause the small conductive object to become electrically energized. Only upon insertion of another object into a second outlet opening would the first electrical contact be electrically energized. 
     These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front perspective view of a tamper resistant electrical outlet in accordance with the present invention; 
         FIG.  2    is a rear perspective view of the electrical outlet of  FIG.  1   ; 
         FIGS.  3 A- 3 C  are side sectional views of another tamper resistance electrical outlet in accordance with the present invention, depicting the progressive simultaneous insertion of two plug prongs into respective outlet openings; 
         FIG.  4    is an exploded view of the tamper resistant electrical outlet of  FIG.  1   ; 
         FIG.  5    is another exploded view of the tamper resistant electrical outlet of  FIG.  1   , rotated about 90 degrees from the view of  FIG.  4   ; 
         FIG.  6 A  is a side sectional view of the tamper resistant electrical outlet of  FIG.  1   ; 
         FIG.  6 B  is another side sectional view of the tamper resistant electrical outlet of  FIG.  1   , shown with a single prong inserted into a left receptacle opening and engaging a left electrical contact while energizing only the right electrical contact; 
         FIG.  6 C  is another side sectional view of the tamper resistant electrical outlet of  FIG.  1   , shown with a single prong inserted into a right receptacle opening and engaging a right electrical contact while energizing only the left electrical contact; and 
         FIG.  6 D  is another side sectional view of the tamper resistant electrical outlet of  FIG.  1   , shown with two prongs inserted into respective ones of the left and right receptacle openings while simultaneously engaging and energizing the left and right electrical contacts. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A tamper resistant electrical outlet provides electrical power, typically 110V AC or 220V AC power, to appliances, lighting, or other electrical consumers that utilize plugs having two or three (or more) prongs. The receptacle includes electrical contacts that are normally in a non-energized or “dead” state, and are only electrically energized or made “live” when a compatible object such as a plug prong is inserted into a receptacle opening associated with a different contact. In this way, prongs of a proper electrical plug may be inserted into the receptacle openings and cause the internal electrical contacts to essentially be “switched on” just before or as the prongs establish contact with the electrical contacts. Because each prong causes only a different contact to be energized, and has no effect on the state (live or dead) of its own contact, insertion of a single object into a single receptacle opening will not result in electrical current flowing to the single object. Because the tamper resistant electrical outlet does not block access to electrical contacts in the manner of an outlet equipped with a shutter mechanism, the plug insertion forces are typically lower than for an outlet with a shutter mechanism, and there is comparatively little to distinguish the tamper resistant outlet from a traditional outlet based on the tamper resistant outlet&#39;s manner of operation and its outward appearance. 
     Referring now to the drawings and illustrative embodiments depicted therein, a tamper resistant electrical receptacle or outlet  10  includes a receptacle body  12  that, in the illustrated embodiment of  FIGS.  1 ,  2 , and  4 - 6 D , is a two-piece body including a main body  14  and an insert body  16  that is partially received in the main body  14 . Main body  14  includes a front face  18  that defines a plurality of receptacle openings  20   a - c  (line  20   a,  neutral  20   b,  ground  20   c ), and further includes a top wall  22  and opposite side walls  24  that extend rearwardly from face  18 , plus a main rear wall portion  26   a  that closes the ends of top wall  22  and side walls  24  to form an interior cavity  28  as shown in  FIG.  5   . Insert body  16  includes an interior or insert portion  30  that is received in interior cavity  28  of main body  14 , a bottom wall  32  that cooperates with front face  18  and side walls  24  to enclose interior cavity  28  (see  FIG.  2   ), and an insert rear wall portion  26   b  that meets main rear wall portion  26   a  to enclose a rear end of receptacle body  12 . Side walls  24  each define a pair of openings  32  for receiving respective latch tabs  43  along the insert portion  30  of the insert body  16 . Latch tabs  34  engage the openings  32  during assembly of receptacle body  12  to secure insert body  16  to main body  14  without need for additional fasteners. Referring to  FIG.  2   , the insert rear wall portion  26   b  cooperates with main rear wall portion  26   a  to define a line wire opening  36   a  and a neutral wire opening  36   b,  and insert rear wall portion  26   b  further defines a ground wire opening  36   c.    
     Also inside the interior cavity  28  are a pair of actuators including a line actuator  38   a  and a neutral actuator  38   b  ( FIGS.  4 - 6 D ), a set of three receptacle contacts including a line receptacle contact  40   a,  a neutral receptacle contact  40   b,  and a ground receptacle contact  40   c,  and a pair of live contacts including a live line contact  42   a  and a live neutral contact  42   b.  In their default or non-engaged positions of  FIGS.  3 A and  6 A , with no objects inserted through receptacle openings  20   a,    20   b,  there is no electrical contact established between receptacle contacts  40   a,    40   b  and live contacts  42   a,    42   b.  Therefore, even when live contacts  42   a,    42   b  are energized, receptacle contacts  40   a,    40   b  are not energized when no objects are inserted through receptacle openings  20   a,    20   b.  As will be described in more detail below, line actuator  38   a  is operable to move a forward contact portion  44  of live line contact  42   a  in an outboard direction and into electrical contact with line receptacle contact  40   a,  in response to insertion of an object through the neutral receptacle opening  20   b  ( FIG.  6 C ). Likewise, neutral actuator  38   b  is operable to move a forward contact portion  44  of neutral line contact  42   b  in an outboard direction and into electrical contact with neutral receptacle contact  40   b,  in response to insertion of an object through the line receptacle opening  20   a  ( FIG.  6 B ). 
     Referring to the simplified drawings of  FIGS.  3 A- 3 C , in which simplified components are illustrated using reference numerals corresponding to those above, but with the addition of a “prime” (′) suffix, the operation of a simplified tamper resistant electrical outlet  10 ′ can be readily understood. An electrical plug  50  has a blade-type line prong  52   a  and a blade-type neutral prong  52   b,  which are compatible for insertion into the line receptacle opening  20   a ′ and neutral receptacle opening  20   b ′, respectively. The line actuator  38   a ′ and neutral actuator  38   b ′ are mounted behind front face  18 ′, each actuator having an upper tip portion  54  that extends at least partly into alignment with the opposite receptacle opening  20   a ′ or  20   b ′. That is, the tip portion  54  of line actuator  38   a ′ extend partly into the pathway defined by neutral receptacle opening  20   b ′ and the tip portion  54  of neutral actuator  38   b ′ extends partly into the pathway defined by line receptacle opening  20   a ′, such as shown in  FIG.  3 A . Each actuator  38   a ′,  38   b ′ also has a rearward actuation nose  56  that is located adjacent and inboard of the forward contact portions  44 ′ of the respective live contacts  42   a ′,  42   b′.    
     In the simplified illustrated embodiment of  FIGS.  3 A- 3 C , the actuators&#39; upper tip portions  54  have sloped surfaces at their outboard ends, so that actuators  38   a ′,  38   b ′ will be urged out of their default positions ( FIG.  3 A ) and toward their actuated positions ( FIGS.  3 B and  3 C ) upon insertion of prongs  52   a,    52   b.  Movement of line actuator  38   a ′ due to insertion of neutral prong  52   b  through neutral receptacle opening  20   b ′ urges the line actuator&#39;s rearward actuation nose  56  outboard (indicated with left-pointing arrows in  FIGS.  3 B and  3 C ), thus pushing the forward contact portion  44  of live line contact  42   a ′ against line receptacle contact  40   a ′ to energize it. Likewise, movement of neutral actuator  38   b ′ due to insertion of line prong  52   a  through line receptacle opening  20   a ′ urges the neutral actuator&#39;s rearward actuation nose  56  outboard (indicated with right-pointing arrows in  FIGS.  3 B and  3 C ), thus pushing the forward contact portion  44  of live neutral contact  42   b ′ against neutral receptacle contact  40   b ′ to energize it. Upon removal of prongs  52   a,    52   b,  the live contacts  42   a ′,  42   b ′ act like leaf springs by returning to their default positions of  FIG.  3 A , thus disengaging from the respective receptacle contacts  40   a ′,  40   b ′ and urging actuators  38   a ′,  38   b ′ back to their neutral positions. 
     It will be appreciated that the simplified sliding movements of actuators  38   a ′,  38   b ′, which need only move a short distance in one direction, and which do not tilt or lock to block access to the receptacle contacts  40   a ′,  40   b ′, allows for less resistance to movement as compared to access-blocking mechanisms that typically tilt, lock, and slide in different directions while engaging and disengaging different surfaces. While outlet receptacles disclosed herein allow for insertion of a small foreign object into one receptacle opening and then engaging the corresponding receptacle contact with the foreign object, that receptacle contact will not become energized unless another foreign object is simultaneously inserted sufficiently far into the other receptacle opening to push the first opening&#39;s live contact into engagement with the corresponding receptacle contact. In this manner, the electrical outlet  10  is made tamper-resistant. 
     Referring once again to  FIGS.  4 - 6 D , actuators  38   a,    38   b  are shown to have more complex shapes than the actuators  38   a ′,  38   b ′ of  FIGS.  3 A- 3 C . Rather than relying on upper tip portions  54  with ramped surfaces that cause lateral movement upon engagement by a plug prong  52   a  or  52   b,  as described above with respect to the simplified drawings of  FIGS.  3 A- 3 C , actuators  38   a,    38   b  have planar front surfaces  60   a,    60   b  that substantially obstruct the respective receptacle openings  20   b,    20   a  (i.e., front surface  60   a  obstructs opening  20   b,  and front surface  60   b  obstructs opening  20   a ). Despite these obstructions, actuators  38   a,    38   b  give little resistance to sliding diagonally rearwardly and laterally away from the receptacle openings  20   b,    20   a  that they normally obstruct, such that users inserting a proper plug  50  will find little difference between the insertion forces required to insert the prongs  52   a,    52   b  into tamper resistant electrical outlet  10  as compared to a conventional (not tamper resistant) electrical outlet. 
     Actuators  38   a,    38   b  are functionally similar to one another, but with minor structural differences that allow for intersecting travel paths without interference, so that the actuators can operate independently of one another. Referring to  FIGS.  4  and  5   , line actuator  38   a  is unitarily formed with a forward portion  62   a  that is normally (default) positioned just rearwardly of the neutral receptacle opening  20   b,  a diagonal middle portion  64   a  that extends rearwardly and laterally inboard from forward portion  62   a,  and a post-like rearward portion  66   a  at a rearward end of the diagonal middle portion  64   a.  Forward portion  62   a  includes a generally planar forward surface  68   a  and a pair of guide tabs including a shorter guide tab  70   a  and a longer guide tab  72   a.  Guide tabs  70   a,    72   a  are slidingly received in respective diagonal channels defined in the main body  14  and/or the insert body  16 , as will be described below. The post-like rearward portion  66   a  and forward portion  62   a  have free ends that extend downwardly (to the upper-left in  FIG.  4   , or to the lower-left in  FIG.  5   ) from diagonal middle portion  64   a.  Rearward portion  66   a  includes the actuation nose  56 , which is a convex partial-cylindrical surface of rearward portion  66   a  that is designed to engage the forward contact portion  44  of live line contact  42   a.    
     Neutral actuator  38   b  is constructed similarly to line actuator  38   a,  including a forward portion  62   b  that is normally (default) positioned just rearwardly of the line receptacle opening  20   a,  a diagonal middle portion  64   b  that extends rearwardly and laterally inboard from forward portion  62   b,  thus cooperating with the line actuator&#39;s middle portion  64   a  to form an X-like shape as shown in  FIGS.  6 A- 6 D , and a post-like rearward portion  66   b  at a rearward end of the diagonal middle portion  64   b.  Forward portion  62   b  includes a generally planar forward surface  68   b  and a pair of guide tabs including a shorter guide tab  70   b  and a longer guide tab  72   b,  the latter being slidingly received in respective diagonal channels defined in the main body  14  and/or the insert body  16 . The post-like rearward portion  66   b  and forward portion  62   b  have free ends that extend upwardly (to the lower-right in  FIG.  4   , or to the upper-right in  FIG.  5   ) from diagonal middle portion  64   b.  Rearward portion  66   b  includes the actuation nose  56  that selectively engages forward contact portion  44  of neutral line contact  42   b.    
     As can be seen in  FIGS.  4  and  6 A- 6 B  (for neutral actuator rearward portion  66   b ) and in  FIG.  5    (for line actuator rearward portion  66   a ), the rearward actuator portions  66   a,    66   b  include partial-cylindrical tip portions  74   a,    74   b  that allows the rearward portions  66   a,    66   b  to partially overlap one another when viewed axially in their default positions, such as shown in  FIG.  6 A . It will be appreciated that the configuration of actuators  38   a,    38   b  is such that they can be identical to one another and installed facing opposite directions, with each actuator&#39;s middle portion  64   a,    64   b  moving diagonally within a space defined between the free ends of the other actuator&#39;s forward and rearward portions. Because the actuators  38   a,    38   b  are identical, the assembly process is simplified and tooling costs are reduced. Actuators  38   a,    38   b  are made of electrically non-conductive material that is sufficiently hard to resist wear from frequent engagement by prongs  52   a,    52   b  of electrical plugs  50 , and from sliding movement during operations. For example, many types of injection molded resinous plastics may be satisfactory. Although it is envisioned that actuators  38   a,    38   b  may be unitarily formed from a single material, it will be appreciated that for abrasion-resistance it may be desirable to form or cover the forward surfaces  68   a,    68   b  with a harder material, potentially even including conductive metals, which may have desirable properties not available from most resinous plastics, such as higher abrasion resistance, greater hardness, and lower coefficient of friction when engaged by a metal plug prong. 
     Referring again to  FIGS.  4  and  5   , partial-cylindrical tip portion  74   a  of line actuator rearward portion  66   a  is received in a diagonal opening  80  formed in insert body  16 , and shorter guide tab  70   a  is received in a diagonal slot  82  formed in insert body  16 . Another diagonal slot (not shown) is formed by main body  14  inside interior cavity  28  receives longer guide tab  72   a.  Longer guide tab  72   b  of neutral actuator  38   b  is received in another diagonal slot  84  formed in insert body  16 , while another diagonal slot (not shown) is formed by main body  14  inside interior cavity  28  to receive shorter guide tab  70   b.  A recess  86  is located adjacent diagonal opening  80  and provides space for rearward portion  66   b  to move. Rearwardly of diagonal opening  80 , slots  82 ,  84 , and recess  86 , there is a live contact support  88  that defines a pair of rearward slots  90  for receiving rearward legs  92  of live contacts  42   a,    42   b,  such as shown in  FIGS.  4  and  6 A- 6 D . A pair of legs  94  extend forwardly from slots  90  and provide support and electrical insulation for generally planar middle portions  96  of the respective live contacts  42   a,    42   b.  Each live contact  42   a,    42   b  includes a respective crimp connector  98  that extends from the planar middle portion  96  and into a respective passageway  100  formed in insert body  16  on either side of live contact support  88 . Crimp connectors  98  mechanically and electrically secure to a line conductor  102   a  and a neutral conductor  102   b,  examples of which are illustrated in the simplified views of  FIGS.  3 A- 3 C , so that live contacts  42   a,    42   b  are always energized once connected to their respective conductors  102   a,    102   b,  which are typically single-strand or multi-strand electrical wires designed to carry  110 V or  220 V AC electrical current from an electrical mains supply. Ground contact  40   c  includes its own crimp connector  104  that aligns with ground wire opening  36   c,  the ground contact  40   c  being accessible through an opening or bore  106  formed through insert body  16 , which opening  106  is aligned with ground receptacle opening  20   c.    
     The operation of actuators  38   a,    38   b  will be understood with reference to the above descriptions of the simplified drawing  FIGS.  3 A- 3 C , and with reference to  FIGS.  6 A- 6 D  and the descriptions that follow. In  FIG.  6 A  live contacts  42   a,    42   b  are in their default or relaxed or non-actuated state, with no prongs or other objects inserted through line receptacle opening  20   a  or neutral receptacle opening  20   b.  In this configuration, both live contacts  42   a,    42   b  are spaced well apart from the respective receptacle contacts  40   a,    40   b  to ensure that receptacle contacts  40   a,    40   b  are non-energized or “dead” in this configuration. It can also be seen in  FIG.  6 A  that the forward contact portion  44  of each live contact  42   a,    42   b  is spaced from each actuation nose  56  of the respective actuators  38   a,    38   b.  Such spacing is not required, but may permit some “play” in the actuators  38   a,    38   b  when the actuators are not engaged by plug prongs, since the resilient spring-like characteristics of contact portions  44  provide a return force to the actuators&#39; default positions of  FIG.  6 A . In this default configuration, both live contacts  42   a,    42   b  can be continuously electrically energized, while neither of the receptacle contacts  40   a,    40   b  is energized. 
     Referring now to  FIG.  6 B , the line prong  52   a  has been inserted sufficiently far into line receptacle opening  20   a  to push neutral actuator  38   b  diagonally so that the actuator&#39;s actuation nose  56  has urged the forward contact portion  44  of live neutral contact  42   b  into electrically conductive engagement with neutral receptacle contact  40   b.  This action renders neutral receptacle contact  40   b  live, as indicated by six small lines shown radiating from the point of conductive engagement, and also by five lines shown radiating from neutral receptacle opening  20   b.  With reference to  FIG.  6 C , the opposite condition of  FIG.  6 B  is shown. That is, in  FIG.  6 C  the neutral prong  52   b  has been inserted sufficiently far into neutral receptacle opening  20   b  to push line actuator  38   a  diagonally so that the actuator&#39;s actuation nose  56  has urged the forward contact portion  44  of live line contact  42   a  into electrically conductive engagement with line receptacle contact  40   a.  This action renders line receptacle contact  40   a  live, as indicated by six small lines shown radiating from the point of conductive engagement, and also by five lines shown radiating from line receptacle opening  20   a.  While  FIGS.  6 B and  6 C  illustrate different conditions with only single prongs  52   a,    52   b  inserted into single receptacle openings  20   a,    20   b,  these drawings also represent the positions that can be assumed by the actuators  38   a,    38   b  and live contacts  42   a,    42   b  if a foreign object such as a paperclip or nail were inserted into either one of receptacle openings  20   a,    20   b.  In each case, the inserted object (represented by prong  52   a  or  52   b ) is not electrically energized despite establishing electrical contact with the respective receptacle contact  40   a  or  40   b.    
     In  FIG.  6 D  there is shown the proper simultaneous insertion of the two plug prongs  52   a,    52   b  into the respective receptacle openings  20   a,    20   b.  Because actuators  38   a,    38   b  operate independently of one another,  FIG.  6 D  is essentially a combination of  FIGS.  6 B and  6 C , demonstrating that there is no conflicting movement of the actuators  38   a,    38   b  as they both move diagonally from their default positions to their fully actuated positions. Each actuator  38   a,    38   b  is permitted to freely move in response to insertion of the respective prong  52   b,    52   a,  and each prong is electrically energized by movement of the respective forward contact portions  44  of live contacts  42   a,    42   b.  It will be appreciated that the full engagement of receptacle contacts  40   a,    40   b  by the respective prongs  52   a,    52   b  will typically force the contacts&#39; arms to spread apart (best shown in  FIG.  3 C  compared to  FIGS.  3 A and  3 B ), which forces the inboard arm into tighter or higher-force engagement with the respective forward contact portion  44  of live contact  42   a  or  42   b.  Thus, electrical contact between forward contact portions  44  and receptacle contacts  40   a,    40   b  is established and enhanced by movement of the respective forward contact portion and inboard arm of the receptacle contact  40   a,    40   b  toward one another, although it is envisioned that sufficient electrical contact may be established by movement of forward contact portions  44  alone. Upon removal of both prongs  52   a,    52   b,  the spring-like forward contact portions  44  of live contacts  42   a,    42   b  force themselves inwardly away from the respective receptacle contacts  40   a,    40   b  and, at the same time, forward contact portions  44  press rearward actuation noses  56  inboard to urge actuators  38   a,    38   b  forwardly to their default positions of  FIG.  6 D . 
     It will be appreciated that the principles of the present invention may be incorporated into different styles of electrical outlets, including duplex (two plug) outlets and outlets having different receptacle opening configurations such as a 20-amp configuration or configurations used in countries around the world, for any receptacles having at least two spaced-apart receptacle openings providing access to receptacle contacts of different polarities. Accordingly, the tamper resistant electrical outlet of the present invention provides improved safety by maintaining the internal receptacle contacts in a non-energized or “dead” state unless an object such as a plug prong is inserted into a different receptacle opening. Thus, a single object inserted through a single receptacle opening can make electrical contact with the internal receptacle contact associated with that opening, and no continuity will be established to a live conductor unless and until a separate insertion takes place in a different opening. Only upon insertion of a second object sufficiently far into a different receptacle opening can the first object be energized, since the second object&#39;s insertion though the different opening is needed establishes a connection from the live conductor to the first object. This allows for a tamper-resistant outlet that, to a proper user, operates substantially the same as a conventional outlet, but with enhanced safety by maintaining the internal receptacle contacts in a non-energized state when the outlet is not in use or when a single object is inserted into a single opening. 
     Changes and modifications in the specifically-described embodiments may be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims as interpreted according to the principles of patent law including the doctrine of equivalents.