Patent Publication Number: US-6699050-B1

Title: Lockable electrical outlet closure plug

Description:
BACKGROUND AND SUMMARY 
     The present disclosure relates to wall-mounted residential and office electrical outlets, and particularly to closure plugs for those outlets. More particularly, the present disclosure relates to lockable electrical outlet closure plugs. 
     Electrical outlets usually include upper and lower sockets adapted to admit plugs coupled to the ends of many kinds of electrical cords. Many juvenile caregivers desire to shield young children from access to these sockets and insert a closure plug into a targeted socket or place a socket cover over the targeted socket. 
     According to the present disclosure, a lockable electrical outlet socket closure plug includes a plug housing and a retainer mounted for movement in the plug housing between locked and unlocked positions. The plug housing includes a pair of socket blades that are adapted to extend into the usual side-by-side blade receiver openings formed in an electrical outlet socket. When moved to the locked position, the retainer engages a flange associated with a ground prong receiver opening in an electrical outlet socket to retain the plug housing in a mounted position shielding the socket. When moved to the unlocked position, the retainer disengages the flange in the socket to release the plug housing so that it can be removed by a caregiver from the electrical outlet socket. 
     In illustrative embodiments, the plug further includes a controller mounted for movement in the plug housing and arranged normally to “reinforce” the retainer so that the retainer cannot be moved from the locked position to the unlocked position. When the caregiver elects to remove the plug housing from the electrical outlet socket, the caregiver first moves the controller relative to the plug housing to “release” the retainer and the caregiver then moves the released retainer from the locked position to the unlocked position to allow the caregiver to remove the plug housing from the electrical outlet socket. 
     Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The detailed description particularly refers to the accompanying figures in which: 
     FIG. 1 is a perspective view of an electrical outlet socket closure plug in accordance with the present disclosure and an electrical outlet socket adapted to receive the plug and showing a retainer mounted for movement in the plug and adapted to extend into a ground prong receiver formed in the socket to retain the plug in a mounted position in the socket; 
     FIG. 2 is a perspective view similar to FIG. 1 showing a plug housing included in the plug locked in a mounted position in the socket and showing a controller including a pair of finger pads that can be moved manually toward one another to free the retainer so that it can be moved relative to the plug housing and the socket and also including an actuator (protruding from an aperture formed in an outer plate of the plug housing) that can be moved manually downwardly (while the finger pads are moved toward one another to positions in the plug housing) to disengage the retainer from the socket so that the plug can be removed from the socket; 
     FIG. 3 is a perspective view of components that can be assembled to produce the electrical outlet socket closure plug of FIGS. 1 and 2 and showing (from right to left) an outer plate formed to include an actuator-receiving aperture, a retainer including a vertically extending latch carrier and a horizontally extending retainer latch cantilevered to the latch carrier, a coiled latch carrier return spring below the latch carrier, a latch controller including the two finger pads, and a plug base including an inner plate and two socket blades (shown in phantom) appended to an exterior surface of the inner plate; 
     FIG. 4 is a perspective view of the inner plate, outer plate, and retainer taken from another point of view showing how the latch carrier can slide upwardly into a vertically extending channel formed in a retainer mount appended to an interior surface of the outer plate; 
     FIG. 5 is a sectional view taken along line  5 — 5  of FIG. 1 showing operation of the coiled latch carrier return spring to move the latch carrier upwardly to cause the retainer latch carried on the latch carrier to engage a retainer flange associated with the socket as shown in FIG. 8 to retain the plug in a mounted position in the socket and showing positioning of a retainer motion blocker located in a middle portion of the latch controller to block downward movement of the latch carrier to maintain engagement of the retainer latch and the socket; 
     FIG. 6 is a sectional view similar to FIG. 5 showing movement of the finger pads of the latch controller toward one another to disengage the retainer motion blocker from the latch carrier to free the latch carrier so that it can be moved downwardly against the underlying coiled latch carrier return spring; 
     FIG. 7 is a sectional view similar to FIGS. 5 and 6 showing downward movement of the latch carrier against an upward force applied by the coiled latch carrier return spring in response to a downward force applied to the protruding actuator while the finger pads are “held” in the positions shown in FIG. 6 to cause the retainer latch carried on the latch carrier to disengage the retainer flange associated with the socket as shown in FIG. 9 to “release” the plug from its mounted position so that it can be removed from the socket; 
     FIG. 8 is a sectional view taken along line  8 — 8  of FIG. 5 showing engagement of a lug on the retainer latch and a retainer flange associated with the socket to block separation of the plug from the electrical outlet socket; 
     FIG. 9 is a sectional view taken along line  9 — 9  of FIG. 7 showing disengagement of the lug on the retainer latch from the retainer flange associated with the socket to allow separation of the outlet plug from the electrical outlet socket; and 
     FIG. 10 is a sectional view similar to FIG. 9 showing separation of the plug from the electrical outlet socket. 
    
    
     DETAILED DESCRIPTION 
     A closure plug  10  includes a plug housing  12 , a retainer  14  including a retainer latch  16  and a latch actuator  18 , and a latch controller  20  as shown, for example, in FIGS. 1-4. During installation, closure plug  10  is inserted into openings formed in an outlet socket  22  of an electrical outlet  24  in the manner suggested in FIG.  1 . Retainer latch  16  engages a latch flange  26  associated with one of the openings once closure plug  10  is mounted on electrical outlet  24  in the manner shown in FIG. 2 to retain closure plug  10  in a releasable but fixed position on electrical outlet  24  as shown, for example, in FIGS. 5 and 8. By first “squeezing” finger pads  28   a  and  28   b  included in latch controller  20  together (as suggested in FIGS. 2,  6 ,  7 ,  9 , and  10 ) and then pushing down on latch actuator  18  (as suggested in FIGS. 2,  7 , and  10 ), retainer latch  16  can be moved to disengage latch flange  26  thereby releasing closure plug  10  from electrical outlet  24 . 
     Plug housing  12  includes an inner plate  29  and an outer plate  30  configured to mate with inner plate  29  to form an interior region  32  therebetween containing portions of retainer  14  and latch controller  20  as suggested in FIGS.  3  and  8 - 10 . Fasteners  34  pass through openings  35  formed in inner plate  29  and collars  36  appended to an interior surface  37  of inner plate  29  and into bores  38  formed in fastener mount posts  39  to anchor inner plate  29  in a fixed position on outer plate  30  as suggested in FIGS. 1,  3 , and  4 . 
     A pair of socket blades  40  are appended to an exterior surface  41  of inner plate  29  as shown, for example, in FIGS. 1 and 4. Each socket blade  40  is adapted to extend into one of the blade receiver openings  42  formed in socket  22  of electrical outlet  24 . Inner plate  29  is formed to include a retainer latch opening  43  adapted to confront a ground prong receiver opening  44  formed in electrical outlet socket  22  following insertion of the pair of socket blades  40  into the blade receiver openings  42 . 
     Retainer  14  also includes a latch carrier  46  and a latch carrier return spring  48  as shown, for example, in FIGS. 3 and 4. Latch carrier  46  includes a carrier body  50  that is sized and shaped to slide up and down in a retainer mount  52  appended to an interior surface  53  of outer plate  30 . In the illustrated embodiment, carrier body  50  is a thin, flat plate. Retainer latch  16  is coupled to a lower end  54  of carrier body  50  and latch actuator  18  comprising a head  55  and a neck  56  is coupled to an upper end  57  of carrier body  50 . 
     Retainer mount  52  on outer plate  30  is configured to receive and support latch carrier  46  for sliding movement relative to inner plate  29  between a locked position shown in FIGS. 2,  5 ,  6 ,  8 , and  9  and an unlocked position shown in FIGS. 7 and 10. In the locked position, retainer latch  16  is adapted to engage retainer flange  26  provided in ground prong receiver opening  44  formed in electrical outlet socket  22  to block movement of inner plate  29  and socket blades  40  away from socket  22 . In the unlocked position, retainer latch  16  is adapted to disengage latch flange  26  to allow movement of inner plate  29  and socket blades  40  away from socket  22 . 
     Latch carrier return spring  48  is arranged in plug housing  12  to yieldably urge latch carrier  46  normally to the locked position to cause latch actuator  18  to extend upwardly through an actuator aperture  58  formed in outer plate  30  to provide means outside of plug housing  12  for manually moving latch carrier  46  against latch carrier return spring  48  from the locked position to the unlocked position (as suggested in FIGS.  7  and  10 ). Such movement causes retainer latch  16  to disengage latch flange  26  of electrical outlet socket  22  so that plug housing  12  can be removed from electrical outlet socket  22 . 
     Plug housing also includes a spring holder  60  coupled to interior surface  37  of inner plate  29  and configured to receive latch carrier return spring  48  therein as suggested in FIGS. 3 and 5. Spring holder  60  includes a spring support floor  62  cantilevered to interior surface  37  and arranged to lie along a lower edge of retainer latch opening  43  and a lower end of latch carrier return spring  48  engages spring support floor  62 . Spring holder  60  further includes a pair of spring support walls  64  arranged to lie in spaced-apart relation to one another to locate retainer latch opening  43  therebetween and to extend upwardly from spring support floor  62  as shown, for example, in FIG.  3 . 
     Retainer  14  also includes a cantilevered spring guide  66  coupled to an underside of retainer latch  16  as shown, for example, in FIGS. 3 and 4. In the illustrated embodiment, latch carrier return spring  48  is a coil configured to wind around cantilevered spring guide  66  and arranged to engage the underside of retainer latch  16 . As shown in FIG. 3, spring support floor  62  is formed to include a spring guide receiver slot  68  and a distal portion of cantilevered spring guide  66  extends below coil  48  and into and through spring guide receiver slot  68  as suggested in FIGS. 5-10. 
     As suggested in FIGS. 3 and 4, retainer latch  16  includes an inner end that is cantilevered to lower end  54  of carrier body  50  and is mated to an upper end of spring guide  66 . An outer end of retainer latch  16  is formed to include an inclined cam ramp  71  and a vertical flange retainer surface  72 . During installation of closure plug  10  on electrical outlet  24 , inclined cam ramp  71  is arranged to engage an outer edge  73  of electrical outlet socket  22  as suggested in FIGS. 1 and 8 to bend the deflectable, cantilevered retainer latch  16  downwardly to pass lug  70  under outer edge  73  and then allow lug  70  to “snap” upwardly into the locked position shown in FIG. 8 owing to the “springiness” of the material used to form retainer latch  16 . In this locked position, vertical flange retainer surface  72  of lug  70  engages flange  26  to retain closure plug  10  in the mounted position on electrical outlet  24  shown in FIGS. 2 and 8. 
     Latch controller  20  is illustrated in FIG.  3  and includes a retainer motion blocker  80  and a blocker return spring  81  positioned to lie between the finger pads  28   a  and  28   b . Retainer motion blocker  80  is coupled to first finger pad  28   a  and mounted for movement in interior region  32  of plug housing  12  between a latch-locking position (shown in FIGS. 5 and 8) blocking movement of latch carrier  46  from the locked position to the unlocked position and a latch-releasing position (shown in FIGS. 6,  7 ,  9 , and  10 ) allowing movement of latch carrier  46  from the locked position to the unlocked position. Blocker return spring  81  is also located in interior region  32  of plug housing  12  and arranged yieldably to urge retainer motion blocker  80  normally to the latch-locking position. Latch controller  20  is configured to provide means for normally blocking movement of retainer  16  from the locked position to the unlocked position to cause retainer  16  to remain in engagement with retainer flange  26  so that plug housing  12  is retained in a mounted position on the electrical outlet socket  22  and for selectively releasing retainer  16  so that retainer  16  can be moved from the locked position to the unlocked position to cause retainer  16  to be released from engagement with retainer flange  26  to allow plug housing  12  to be dismounted from electrical outlet socket  22 . 
     First finger pad  28   a  is coupled to retainer motion blocker  80  as shown, for example, in FIG.  3 . First finger pad  28   a  is arranged to extend and move through a first side opening  82  formed in plug housing  12  to provide means for manually moving retainer motion blocker  80  against a biasing force generated by blocker return spring  81  to urge retainer motion blocker  80  upwardly to the latch-releasing position (shown in FIG. 6) so that latch carrier  46  is free to move to the unlocked position in response to movement of latch actuator  18  in a downward direction  83  toward latch carrier return spring  48 . Second finger pad  28   b  is coupled to latch carrier return spring  48  and arranged to extend and move through a second side opening  84  formed in plug housing  12  as shown, for example, in FIGS. 2 and 5. 
     As suggested in FIG. 3, a monolithic member is configured to define first and second finger pads  28   a  and  28   b , retainer motion blocker  80 , and blocker return spring  81 . In one embodiment, that monolithic member is made of a plastics material. In the illustrated embodiment, retainer motion blocker  80  is positioned to lie between blocker return spring  81  and first finger pad  28   a.    
     As suggested in FIG. 3, blocker return spring  81  is a compliant Y-shaped strip having a center leg  85  coupled to retainer motion blocker  80  and a pair of arms  86 ,  87 . Each arm  86 ,  87  has a first end coupled to center leg  85  and a second end arranged to contact an inner wall  88  of outer plate  30 . Each arm  86 ,  87  has a serpentine shape in the illustrated embodiment. Each arm  86 ,  87  has a second end coupled to second finger pad  28   b.    
     As shown in FIG. 4, two slide posts  91 ,  92  are coupled to an interior surface of outer plate  30  and arranged to lie in interior region  32  between inner and outer plates  29 ,  30 . First finger pad  28   a  is formed to include a pair of slide post receiver guide slots  93 ,  94  as shown in FIG.  3 . Each slide post  91 ,  92  is arranged to extend into one of the slide post receiver guide slot  93 ,  94  and move back and forth therein during movement of first and second finger pads  28   a  and  28   b  toward and away from blocker return spring  81  as shown in FIGS. 5-7. Slide posts  91 ,  92  are arranged to engage first finger pad  28   a  as shown in FIG. 5 to limit movement of first finger pad  28   a  and retainer motion blocker  80  relative to latch carrier  46  to locate retainer motion blocker  80  normally in the latch-locking position. Fixed support posts  89  are cantilevered to interior surface  53  of outer plate  30  and arranged to locate one of the fastener mount posts  39  therebetween as shown in FIG. 4 to provide means for supporting inner plate  29  relative to outer plate  30 . 
     Retainer  14  also includes a motion-limiter post  95  as shown, for example, in FIGS. 3-5. Motion-limiter post  95  is coupled to carrier body  50  of latch carrier  46  and arranged to extend toward inner plate  29 . Retainer motion blocker  80  includes an interior edge  96  defining an opening receiving motion-limiter post  95  therein as shown, for example, in FIGS. 5-8. Motion-limiter post  95  is arranged to engage interior edge  96  to limit movement of retainer motion blocker  80  relative to latch carrier  46  to locate retainer motion blocker  80  normally in the latch-blocking position. 
     As shown in FIG. 5, interior edge  96  of retainer motion blocker  80  has a trapezoidal shape and includes a long base wall  97  in spaced-apart relation to blocker return spring  81 , a short base wall  98  located between blocker return spring  81  and long base wall  97 , a horizontally extending wall  99  interconnecting upper ends of long and short base walls  97 ,  98 , and a diagonally extending wall  100  interconnecting lower ends of long and short base walls  97 ,  98 . This trapezoidal shape of interior edge  96  provides means for allowing travel of motion-limiter post  95  in the opening “ 96 ” along long base wall  97  between horizontally and diagonally extending walls  99 ,  100  during movement of latch carrier  46  between the locked and unlocked positions. 
     As shown in FIG. 4, retainer mount  52  includes a pair of L-shaped flanges  110  positioned to lie in confronting spaced-apart parallel relation to one another to define a wide-mouth channel  111  receiving carrier body  50  for sliding movement therein and a narrow-mouth channel  112  receiving retainer latch  16  for sliding movement therein during movement of latch carrier  46  between the locked and unlocked positions. L-shaped flanges  110  are configured to cause the wide-mouth channel  111  to have a width that is greater than a width of the narrow-mouth channel  112 . Outer plate  30  includes a side wall  114  appended to L-shaped flanges  110  and a lower wall  116  arranged to extend between side wall  114  and the inner plate  29  and formed to include an opening  118  into the wide-mouth channel  111  sized to admit carrier body  50  into the wide-mouth channel  111 .