Abstract:
A safety guard device for an electrical wall outlet which includes a base plate adapted to be fixed to an electrical receptacle, said base plate containing at least one aperture therein which is in registry with the electrical receptacle, a cover plate in slidable engagement with the base plate for covering the base plate, said cover plate containing an aperture which is positioned to provide selective registry with the aperture in the base plate and thus access to the electrical receptacle, and locking means operatively associated with the base plate and cover plate for locking the plates relative to each other when the electrical receptacle is covered by the cover plate.

Description:
The present invention is a continuation-in-part of application Ser. No. 09/494,430 filed Jan. 31, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a safety guard device for an electrical wall outlet and more particularly to an improved safety plate device containing a manually slidable panel which is provided with an opening which provides access to an electrical wall outlet, but which also can prevent access to such an outlet when the outlet is not otherwise occupied by an electrical plug. Advantageously, the safety guard device is provided with a locking system for locking the manually slidable panel to prevent access to the electrical outlet. 
     2. Description of Related Art 
     Generally, since the introduction of electrical power in homes, there has always been a problem of safety, especially where children are present. Various types of safety cover plates for electrical wall outlets are known in the art. 
     For example, U.S. Pat. No. 3,068,442 issued to Kubik et al. employs a set of covers that shield the socket openings. Through a single control, all of the socket openings may be exposed simultaneously for use. When a plug is removed, the cover, which is spring-biased, closes. The cover slide is manually actuated with a vertically positioned control that unlatches the covers. 
     U.S. Pat. No. 4,605,270 issued to Aslizadeh describes a protective cover for an electrical outlet that comprises a pair of slidable closure plates and a pair of coil spring-actuated blocking plates, wherein both plates are positioned within the boundaries of the rectangular openings in the front wall of the cover. 
     U.S. Pat. No. 4,607,136 issued to Thomas teaches a child-proof protective device with a plate which covers and registers with a plug. The plate includes a pair of slidable doors or panels which are releasably locked in position with a pair of sliding, locking members, one positioned on the top and one positioned on the bottom, thereby precluding operation by children with small hands. 
     U.S. Pat. No. 4,711,634 issued to Antone II et al. employs a face plate with independent closures, each of the closures being biased to a closed position by tensioning members, such as rubber bands or helical springs. The receptacle is covered by guides positioned within the cover plate using a mortise and tenon joint. 
     Steinhilber et al. discloses in U.S. Pat. No. 4,731,511 a decorative wall plate and slider cap. A slider member having two barbed clips interact with protruding rail members for containment and fingers act as cams to move a toggle in the vertical direction. A decorative cap gives form to the toggle switch. 
     U.S. Pat. No. 4,733,017 issued to Wolf-Taylor et al. employs a pair of spring-loaded sliding, traverse plates which shift to open and closed positions in front of an electrical wall outlet receptacle. The plates are in tracks and automatically spring to enclose the plug when released. 
     U.S. Pat. Nos. 4,793,818 and 4,857,004 issued to Poirier disclose a safety guard which comprises a cover with a pair of openings adapted to be mounted over an electrical wall outlet and closure elements which are slidably mounted to the cover to expose or to cover the openings in registry with the sockets of the wall outlet. 
     Although these protective systems provide for spring-actuated blocking plates which are movable to automatically cover the socket openings if a plug is removed from a socket, they are not fully protective in that most children will be able to master the sliding movement of the plates, either accidentally or through observation. 
     U.S. Pat. No. 4,952,755 issued to Engel et al. discloses a safety plate for electrical outlets which includes a cover plate having apertures therein for receiving the prongs of an electrical plug. A pair of slidable panels also having apertures for the prongs of a plug are mounted to the back of the cover plate and are held in place by a back plate. 
     U.S. Pat. No. 5,212,347 issued to Power et al. discloses an electrical apparatus cover plate which has an enclosing base plate mounted on a wall over an electrical outlet and a protective shield that is retained through a dovetail arrangement provided in the base plate and covers the outlet for protection. However, the operation of both of these electrical devices can be difficult in operation. 
     The present inventor is also prosecuting another U.S. application Ser. No. 09/494,430, filed Jan. 31, 2000, which discloses a safety guard device for an electrical outlet which also includes locking members for locking or unlocking a base plate to a cover plate. The base plate can be slidably interlocked through the pair of guides, and the bottom opening of the cover plate can be used with a lower opening or an upper opening of the base plate for preventing access to the wall outlet when an electrical plug is not inserted. However, this safety guard device for an electrical outlet includes locking members and guides located at the top portion thereof, respectively. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a safety guard device for an electrical wall outlet which eliminates the above problems encountered with conventional safety cover plates for an electrical wall outlet. 
     Another object of the present invention is to provide a safety plate device which includes a manually slidable panel having an opening for protecting an electrical wall outlet designed to prevent access to such outlet when an electrical plug is not inserted. 
     A further object of the present invention is to provide a safety guard device for an electrical wall outlet which includes a base plate having upper and lower openings and a pair of locking members extending from the bottom thereof and a cover plate having a bottom opening and a pair of apertures disposed at the bottom thereof for slidably interlocking with the locking members of the base plate. 
     Still another object of the present invention is to provide a safety guard device for an electrical wall outlet which includes a base plate having upper and lower openings and a pair of locking members provided on opposite sides, e.g., on the upper left side and on the lower right side thereof, and a cover plate having a bottom opening and a pair of engaging and releasing members for slidably interlocking with the locking member of the base plate. 
     Yet another object of the present invention is to provide a safety guard device for an electrical wall outlet which is simple in structure, inexpensive to manufacture, durable in use and refined in appearance. 
     Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
     Briefly described, the present invention is directed to a safety guard device for an electrical outlet which includes a base plate having a pair of openings and a pair of locking members extended from the bottom thereof and a cover plate having a bottom opening and a pair of slots located at the bottom thereof, whereby the locking members of the base plate can be locked to the cover plate or unlocked from the cover plate. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a perspective view of the safety guard device for an electrical wall outlet according to the present invention; 
     FIG. 2 is an exploded, perspective view of the safety guard device of the present invention and a conventional electrical wall outlet to be secured to a wire box; 
     FIG. 3 is a perspective view showing a pair of locking members on the base plate and a pair of engaging members on the cover plate of the safety guard device according to the present invention, showing the locking or unlocking positions thereof; 
     FIG. 4 is a perspective view of the safety guard device according to the present invention showing the use of one plug which is inserted into the electrical outlet through the present device in an unlocking position; 
     FIG. 5 is a perspective view of the safety guard device according to the present invention showing the insertion of two plugs into the outlets through the present device in an unlocking position; 
     FIG. 6 is a perspective view of the safety guard device according to the present invention showing the cover plate automatically separated from the base plate due to gravity; 
     FIG. 7 is a bottom perspective view of the safety guard device of the present invention showing the base plate assembled with the cover plate and an enlarged guide member attached to the cover plate; 
     FIG. 8 is a perspective view showing a pair of locking members on a base plate and a pair of engaging members on a cover plate in another embodiment of the safety guard device of the present invention; 
     FIG. 9 is a perspective view of the safety guard device according to the present invention showing the use of one plug which is inserted into the electrical outlet through the present device, in an unlocking position; 
     FIG. 10 is a perspective view of the safety guard device according to the present invention showing two plugs inserted into outlets through the present device, in an unlocking position; 
     FIG. 11 is a perspective view of the safety guard device according to the present invention showing the base plate automatically separated from the cover plate due to gravity; and 
     FIG. 12 is a bottom view of the safety guard device of the present invention showing the base plate assembled with the cover plate and an enlarged guide member attached to the cover plate. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, the safety guard device for an electrical wall outlet as shown in FIGS. 1,  2  and  3  comprises a cover plate  11  having a bottom opening  16 , the cover plate being slidably mounted to a base plate  12  having an upper opening  14  and a lower opening  15 . These upper, lower and bottom openings  14 ,  15  and  16  are substantially similar openings and are the same size as the upper and lower receptacles  23  and  24  of a double-outlet electrical receptacle  13 . The cover plate  11  has a C-shaped frame  33  for slidably engaging the base plate  12 . Also, the base plate  12  is a rectangular frame  29 . Both cover plate and base plate  11  and  12  can be made of a transparent or opaque material such as a plastic or like material. 
     As shown in FIGS. 3,  6  and  7 , the cover plate  11  includes a cover plate front wall  17  having the bottom opening  16  disposed on the bottom and lowest area thereof, a C-shaped frame  33 , a pair of engaging grooves  27  disposed on the bottom corner of both sides of the frame  33 , and a pair of guiding strips or protrusions  20  extending from the middle portion of both sides of the frame  33 . 
     Referring to FIGS. 2,  3  and  7 , the base plate  12  includes a base plate front wall  31  having the upper and lower openings  14  and  15  disposed in the central area thereof for corresponding registry with the upper and lower receptacles  23  and  24  of the electrical receptacle  13  which is, in turn, secured to the wire box (not shown) through screws  25 . A first aperture  22  is disposed between both upper and lower openings  14  and  15  for securing the base plate  12  to the double-outlet electrical receptacle  13  through a bolt  21  and a second aperture  26  is provided in the double-outlet electrical receptacle  13 . The rectangular frame  29  slidably moves under the guiding strips or protrusions  20  of the cover plate  11 . The first aperture  22  is provided with a supporting plate  32  for supporting to the first aperture  22  (FIG.  7 ). 
     The base plate  12  is provided with a pair of lateral slits  19  which contain a pair of locking and unlocking handles  18  for extending into and engaging a pair of lateral grooves  27  provided in the cover plate  11 . Therefore, each locking or unlocking handle  18  has a locking projection  18 ′ for flexibly locking with the engaging groove  27  or smoothly disengaging from the engaging groove  27  (FIG. 6) by pushing the locking or unlocking handles  18  simultaneously with a thumb and index finger in the direction indicated by arrow (A) from a locking position to the unlocked position shown in FIG.  3 . The grooves  27  are larger than the locking projection  18 ′ of the locking or unlocking handles  18 , respectively, for freely moving into and out of the grooves  27 . It should be understood that other types of locking mechanisms can be used and can be selectively provided on either the base plate  12  or the cover plate  11 . However, the location of the locking mechanisms at the bottom of the device and the required use of both locking mechanisms, simultaneously provides more security for unwanted access to the electrical outlet. 
     As shown in FIG. 3, the cover plate  11  can move up slidably in the direction indicated by arrow (B). Therefore, when the bottom opening  16  of the cover plate  11  matches with the lower opening  15  of the base plate  12 , the plug  30  can be inserted into the lower receptacle  24  (FIG.  4 ). If two plugs are needed, the cover plate  11  is merely moved up further until the bottom opening  16  matches with the upper opening  14 . Thereafter, the pair of plugs  30  can be inserted into the upper and lower receptacles  23  and  24  (FIG.  5 ). After that, when the plugs  30  are taken out, the cover plate  11  can slide down automatically due to gravity (FIG. 6) and finally the cover plate  11  can be locked to the base plate  12  (FIG.  1 ). 
     Referring to FIGS. 4,  5  and  6 , the safety guard device  10  for an electrical wall outlet according to the present invention operates as follows. As shown in FIG. 1, the safety guard device  10  maintains a locking stage in an original position. In order to use the electrical outlet, the handles  18  with the projections  18 ′ are disengaged from the grooves  27  (FIG. 6) of the cover plate  11 , and the cover plate  11  is pushed in the direction indicated by the arrow (B) as shown in FIG.  3 . 
     In the direction indicated by arrow (C) shown in FIG. 4, the upward movement of the cover plate  11  causes the bottom opening  16  thereof to match with the lower opening  15  of the base plate  12 . Accordingly, a plug  30  can be inserted into the lower receptacle  24  of the double-outlet electrical receptacle  13  as shown in FIG.  4 . At this time, the upper receptacle  23  of the double-outlet electrical receptacle is safely masked and protected by the cover plate front wall  17  of the cover plate  11 , thereby protecting children from electrical shock. 
     As shown in FIG. 5, in order to utilize the double outlets  23  and  24 , the further upward movement of the cover plate  11  in the direction indicated by arrow (D) shown in FIG. 5 causes the bottom  16  thereof to match with the upper opening  14  of the base plate  12 . Accordingly, another plug  30  can be inserted into the upper receptacle  23  of the double-outlet electrical receptacle  13  (FIG.  5 ). Thus, the upper and lower outlets  23  and  24  of the double-outlet electrical receptacle  13  are safety masked and protected by the pair of plugs  30 . 
     FIG. 6 shows a perspective view of the safety guard device  10  according to the present invention explaining how the cover plate  11  moves in a reverse direction when the plugs  30  are removed from the receptacles  23  and  24 . For example, when the plug  30  is taken out from the receptacle  24  in the direction indicted by arrow (E), the cover plate  11  falls down naturally due to the weight of the cover plate  11  in the direction indicated by arrow (F) as shown in FIG.  6 . 
     Accordingly, the cover plate  11  moves down until the pair of projections  18 ′ of the handles  18  of the cover plate  11  lock with the pair of grooves  27  of the base plate  12  as shown in FIG.  1 . 
     FIGS. 8,  9 ,  10 ,  11  and  12  show another embodiment of a safety guard device  100  according to the present invention which comprises a cover plate  110  having a bottom opening  16 , the cover plate being slidably mounted to a base plate  120  having an upper opening  14  and a lower opening  15 . These upper, lower and bottom openings  14 ,  15  and  16  are substantially similar openings and are the same size as the upper and lower receptacles  23  and  24  of a double-outlet electrical receptacle  13  (FIG.  2 ). The cover plate  110  has a C-shaped frame  330  for slidably engaging the base plate  120 . Also, the base plate  120  is a rectangular frame  29 . Both cover plate and base plate  110  and  120  are made of transparent or opaque materials such as plastics, and the like. 
     As shown in FIGS. 8,  11  and  12 , the cover plate  110  includes a cover plate front wall  17  having the bottom opening  16  disposed on the bottom and lowest area thereof, a C-shaped frame  330 , a pair of locking and unlocking handles  18  extending from the lower and upper portions of both sides of the frame  330 , a pair of tapered guiding protrusions  330 ′ extending from the lower and upper portions of both sides of the frame  330  and a pair of guiding protrusions  20  extending from the middle portion of both sides of the frame  330 . Each handle  18  is made flexible by the use of handle slit  190 . Also, each handle  18  has a locking protrusion  181  for locking the base plate  120  and has a rugged surface for improving the gripping function thereof. 
     Referring to FIGS. 2,  8  and  12 , the base plate  120  includes a base plate front wall  31  having the upper and lower openings  14  and  15  disposed on the central area thereof for correspondingly registering with the upper and lower receptacles  23  and  24  of the electrical receptacle  13  which is, in turn, secured to the wire box (not shown) through screws  25 . A first aperture  22  is disposed between both upper and lower openings  14  and  15  for securing the base plate  120  to the double-outlet electrical receptacle  13  through a bolt  21  and a second aperture  26  is provided in the double-outlet electrical receptacle  13 . The rectangular frame  29  slidably moves under the guiding protrusions  20  of the cover plate  11 . The first aperture  22  is provided with a supporting plate  32  for supporting to the first aperture  22  (FIG.  12 ). 
     The base plate  120  contains a pair of locking or unlocking levers  19  extending to engage a pair of locking and unlocking handles  18  provided in the cover plate  11 . Each locking or unlocking lever  19  has a locking projection  19 ′ for locking with the locking protrusion  18 ′ or for unlocking from the locking protrusion  18 ′ by pushing the locking or unlocking handles  18  simultaneously with a thumb and index finger in the direction indicated by arrow (A) from a locking position to the doted, unlocked position shown in FIG.  8 . The locking protrusions  18 ′ are the same size as the locking projection  19 ′ of the locking or unlocking handles  18 , respectively, for tightly locking and freely unlocking the cover plate and the base plate from each other. It should be understood that other types of locking mechanisms can be used and can be selectively provided on either the base plate  120  or the cover plate  110 . 
     As shown in FIG. 8, the cover plate  110  can move up slidably in the direction indicated by arrow (B). Therefore, when the bottom opening  16  of the cover plate  110  matches with the lower opening  15  of the base plate  120 , the plug  30  can be inserted into the lower receptacle  24  (FIG.  9 ). If two plugs are needed, the cover plate  110  is merely moved up further until the bottom opening  16  matches with the upper opening  14 . Thereafter, the pair of plugs  30  can insert into the upper and lower receptacles  23  and  24  (FIG.  10 ). After that, when the plugs  30  are taken out, the cover plate  110  can slide down automatically by gravity (FIG. 11) and finally the cover plate  11  can be locked to the base plate  12 . 
     Referring to FIGS. 9,  10  and  11 , the safety guard device  100  for an electrical wall outlet according to the present invention operates as follows. As shown in FIG. 8, the safety guard device  100  maintains a locking stage in an original position. In order to use the electrical outlet, the handles  18  with the projections  18 ′ of the cover plate  110  are disengaged from the locking or unlocking projection  19 ′ of the lever  19  of the base plate  120  when cover plate  110  is pushed in the direction indicated by the arrow (A) as shown in FIG.  8 . The base plate  120  is slidably moved in the upward direction. 
     In the direction indicated by arrow (C) shown in FIG. 4, the upward movement of the base plate  120  causes the bottom opening  16  thereof to match with the lower opening  15  of the cover plate  110 . Accordingly, a plug  30  can be inserted into the lower receptacle  24  of the double-outlet electrical receptacle  13  as shown in FIG.  9 . At this time, the upper receptacle  23  of the double-outlet electrical receptacle  13  is safely masked and protected by the cover plate front wall  17  of the cover plate  110 , thereby protecting children from electrical shock. The lever  19  is provided with a lateral slit  190 ′ in the base plate  120  for improving the flexibility thereof as shown in FIG.  12 . 
     As shown in FIG. 10, in order to utilize the double outlets  23  and  24 , the further upward movement of the base plate  120  in the direction indicated by arrow (D) shown in FIG. 10 causes the bottom  16  thereof to match with the upper opening  14  of the cover plate  110 . Accordingly, another plug  30  can be inserted into the upper receptacle  23  of the double-outlet electrical receptacle  13  (FIG.  10 ). Thus, the upper and lower outlets  23  and  24  of the double-outlet electrical receptacle  13  are safety masked and protected by the pair of plugs  30 . 
     FIG. 11 shows a perspective view of the safety guard device  100  according to the present invention explaining how the cover plate  11  moves in a reverse direction when the plugs  30  are removed from the receptacles  23  and  24 . For example, when the plug  30  is taken out from the receptacle  24  in the direction indicted by arrow (E), the cover plate  11  falls down naturally due to the weight of the cover plate  11  in the direction indicated by arrow (F) as shown in FIG.  11 . 
     Accordingly, the cover plate  110  moves up until the pair of projections  18 ′ of the handles  18  of the cover plate  11  lock with the locking projections  19 ′ of the pair of levers  19  of the base plate  120  as shown in FIG.  8 . 
     Accordingly, the safety guard devices  10  and  100  for an electrical wall outlet according to the present invention is simple in structure compared with conventional safety cover plates containing a spring. Also, the inventive device is compact for portability, inexpensive to manufacture, durable in use compared with a conventional plug-in device and refined in appearance. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included in the scope of the following claims.