Abstract:
Electrical receptacle safety covering means and method, to protect persons too young to appreciate the hazards of electricity from access to the outlets of electrical receptacles by requiring skills of an older child or adult to uncover such a receptacle. Spring-biased security is provided in which an action separate from closing a cover over an electrical receptacle is required to latch the cover, and unlatching it can not be accomplished by pulling on the cover in its opening direction but necessitates overcoming a latching spring-bias in a separate preliminary unlatching step. A combination of a receptacle plate (more or less flush with the receptacle) and a cover for the front thereof has at least one spring and a cooperating slide adapted to move relative thereto between a latched position free of spring bias and an unlatched position subject to spring bias. Preferably the cover carries a pair of such slides and springs, and the plate has grooved flanges engaged by the slides only in the latched position.

Description:
FIELD OF THE INVENTION 
     This invention relates to safety covering of the outlets of electrical receptacles, and concerns especially secure latching of outlet covers, to protect infants, etc. from electrical shock. 
     BACKGROUND OF THE INVENTION 
     Protection of children and pets from ill effects of curiosity about electrical receptacles is well recognized as an objective, and various types of covering for such outlets have been devised. Examples of more or less childproof covers, pivotally attached to special receptacle base plates or housings, having various spring latches appear in Davis U.S. Pat. No. 4,451,101; Carvel U.S. Pat. No. 4,508,933; and Stanback U.S. Pat. No. 3,334,770. Such covers, upon being forcibly closed, flex some latching spring member and become latched automatically. Reopening the cover is intended to be accomplished by flexing such self-latching spring member again to unlatch it, thus enabling the cover to be pivoted open with application of minimal force. 
     Unfortunately, such devices may be reopened by forcing the cover itself in the opening direction, although intended to be unlatched first as just noted. Weakening of a spring latching member by continued usage, or intentional distortion of such a member by a user so as to release the latch more easily, can be expected to defeat the safety feature--and possibly subject the manufacturer to product liability if electric shock ensues. 
     Another disadvantage of such devices is that they render the electrical receptacle unusable with the cover closed, and when in use with the cover open are as hazardous as an unprotected outlet. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to protect persons too young to appreciate the hazards of electricity from access to the outlets of electrical receptacles, by covering the outlets so as to require skills of an older child or adult to uncover them. 
     Another object of this invention is to provide a spring-biased protective cover arrangement in which action separate from closing the cover is required to latch it and, hence, unlatching it can not be accomplished by pulling on the cover in its opening direction. 
     A further object of the invention is to enable an electrical receptacle to be used while closed from view by a protective cover. 
     In general, the objects of this invention are accomplished by separating the protective function of safety covering of electrical receptacles into discrete cooperating latching and spring-biasing safety or security functions. 
     More particularly, the invention is conveniently embodied, for an electrical receptacle, in a combination of plate means (more or less flush with the receptacle) and of covering means for the front thereof, wherein one such means carries along an edge thereof both a spring member and a slide member adapted to move relative thereto between a latched position free of spring bias and an unlatched position subject to spring bias. In a preferred embodiment, the covering means carries a pair of such slide and spring members. 
     Other objects of the present invention, together with means and methods for accomplishing the various objects, will be apparent from the following description and the accompanying diagrams of one or more embodiments of the invention, being presented by way of example rather than limitation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevation of an electrical receptacle plate modified according to this invention; 
     FIG. 2 is a sectional plan through the same plate, taken at II--II in FIG. 1; 
     FIG. 3 is a right side elevation of the apparatus of FIGS. 1 and 2 covered according to the invention; 
     FIG. 4 is a front elevation of the apparatus of FIG. 3; 
     FIG. 5 is a sectional plan of the same apparatus taken at V--V in FIG. 4; and 
     FIG. 6 is a plan view of the same apparatus still closed or covered but with an alternative open view shown in dashed lines. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows, in front elevation, receptacle plate 10 of the present invention having upper and lower openings 12 and 14 to fit in conventional manner over two correspondingly shaped electrical receptacle outlet members 12&#39; and 14&#39; (in dashed lines) and thus to admit electrical plugs (not shown). The plate also has upper and lower smaller openings 16 and 18 to receive screws (not shown) for securing the plate as usual to such an electrical receptacle. Top edge 11, left edge 13, and bottom edge 19, project from the back (hidden here) of the receptacle plate forward beyond the receptacle which lies in the plane of the view, whereas right edge 17 is flush with the face of the receptacle, as shown in detail later. Extending from left edge 13, pair of hinge socket butts 23 and 29, are spaced respectively below the plate top edge and flush with its bottom edge, with vertical bore 22 in socket butt 23, and a like bore 28 in socket butt 29, as indicated in dashed lines. Extending along its right side, plate 10 has pair of short top and bottom flanges 33 and 39, flush with the plate&#39;s corresponding horizontal edges. Each such flange is grooved vertically along its rear surface beginning a short way from such horizontal edge and extending to the opposite horizontal edge of the flange, as indicated in dashed lines for groove 32 in flange 33 and groove 38 in flange 39. Pair of slots 36 and 37 (shown in dashed lines) in bottom edge 19 of the receptacle plate are available as passages for electrical cords (not shown) to the outside when covered, as shown subsequently. 
     FIG. 2 shows receptacle plate 10 in sectional plan, midway through lower receptacle opening 14, as indicated at II--II. This view illustrates more clearly the recessing of right edge 17 and the forward extent of left edge 13 and bottom edge 19, with pair of cord slots 36 and 37 therein. Also visible, here are lower hinge butt 29 with bore 28 therein, and lower flange 39 with groove 38 in the rear face thereof. 
     FIG. 3 shows, in right side elevation, receptacle plate 10 and receptacle cover 40 as an assembled embodiment of this invention, in closed position. The cover has top, bottom, and right edges 41, 49, and 47 (left edge 43 is hidden in this view) and is generelly frustopyramidal in shape, as shown more clearly in later views. The cover has central face 55 parallel to the plate and has oblique top and bottom faces 51 and 59 also perpendicular to the plane of this view (and, thus, shown here only as lines), oblique right face 57 visible here, and oblique left face 53 (hidden). Right side edge 47 of the cover carries upper spring tab 66 projecting outward from the side surface with its lower end integral therewith and its upper end free and projecting outward just below slide 56. Lower spring tab 68 is a mirror image of the upper tab but has lower slide 58 overlying it and, thus, is indicated in dashed lines. 
     Thus, in FIG. 3, the upper slide is shown in the latched position, and the lower slide is shown in the unlatched position. It will be apparent that the protruding tab end would have to be depressed to enable the upper slide to be moved down from its present position (partly overlying grooved flange 33 of receptacle plate 10) wholly onto cover 40 before the cover could be pivoted to the uncovering or open position away from the face of the plate. 
     FIGS. 4 and 5, show embodiment 1 of this invention, in side elevation and sectional plan, respectively. 
     Visible in FIG. 4 are upper, left, right, and lower oblique faces 51, 53, 57, and 59 (as well as vertical central face 55) of cover 40, terminating at respective upper, left, right, and lower edges 41, 43, 47, and 49 of the cover. Vertical central face 55 of the cover is bounded by the oblique faces. Protruding at the left edge of the cover are upper and lower hinge pin butts 20 and 26 resting upon receptacle plate socket butts 23 and 29, respectively. Also prominent is the free end of upper spring tab 66 projecting to the right beyond the right side surface of the cover just below the bottom end of upper slide 56. Lower slide 58 overlies lower spring tab 68, which is indicated in dashed lines. As shown in succeeding diagrams, the slides are generally U-shaped in plan and ridged at their inner edges (like type serifs at the top of the U) to ride in vertical front groove 44 and in rear groove 46 (hidden) along the right edge of the cover and aligned grooves 32 and 38 in the rear surfaces of flanges 33 and 39 of plate 10 (FIG. 1). 
     FIG. 5 shows the same assembled embodiment in sectional plan as taken at V--V in FIG. 4, looking downward from a level between the bottom end of latched upper slide 56 (not seen) and the free end of latching spring tab 66, on the one hand, and on the other hand at the level of the the junction between oblique surface 51 and vertical surface 55 of cover 40. Visible, except to the extent it is obscured by the protruding end of upper spring tab 66 is the upper end of lower slide 58, whose ridged edges are retained wholly within front and rear grooves 44 and 46 of the cover. 
     FIG. 6 shows the same assembled embodiment in plan, still in the closed or covered position but also indicating an alternative open position of cover 40 in dashed lines. Visible at the left is the top of hinge pin butt 20 integral with cover 40 and flush with top edge 41 thereof. 
     Also visible end-on, at the right in FIG. 6, is upper slide 56, the upper portion of whose ridged edge at the rear is engaged in groove 32 in plate flange 33, and all of whose ridged edge at the front is engaged in groove 44 along the right side edge of the front of the cover; its lower ridged portions are riding in the latter groove at the front and in matching groove 46 along the same side edge of the rear face of the cover. The open cover position, indicated here in dashed lines, is attainable only if both slides are positioned over their respective adjacent spring tabs, of course, and wholly disengaged from the aligned plate flanges. 
     Operation of the illustrated and described embodiment of this invention is readily understood. When the cover is in its closed position, with either (or both) of the slides latched between a (the) protruding tab end(s) and adjacent corner(s) of the assembly, the cover cannot be opened unless and until each protruding tab end is depressed (manually) and both of the slides are slid thereover far enough to disengage each slide from the corresponding grooved flange on the receptacle plate. To do so requires such a degree of hand-eye coordination and strength as to preclude young infants (as well as animals) from doing so, whereas adults and older children should have little or no difficulty. 
     Similarly, for the open cover to be reclosed, both slides must clear the plate flanges. If they are still overlying their spring tabs, little or no adjustment should be necessary. If not, the tab end(s) should be depressed by hand and the slides then be slid thereover until clear of the flanges. After the cover is closed, it can be latched shut by sliding at least one at least one slide onto the adjacent flange (preferably both) over and past the adjacent spring tab until the free end protrudes, thereby trapping the adjacent slide partly overlying a flange of the plate, and thereby securing the cover in its closed position. 
     Although in the described and illustrated embodiment the cover carries the latching spring tabs and slides permanently, and the slides engage the plate flanges only when the cover is closed, the situation could be reversed so that the flanges could be on the cover and the latching spring tabs and slides be carried by the plate, suitably grooved to do so as the cover has been shown to be. 
     It will be apparent that the latch of this invention cannot be defeated by pulling on the cover in the opening direction because the functions of closing and latching are separate, rather than combined into the flexing of some spring member, as is common. 
     Moreover, movement of the slide(s) between the latched and unlatched positions is perpendicular to the opening direction, and deflection of the spring tabs to enable such movement of the slides is perpendicular to both the other two movements. More in the way of understanding and manipulation is required than small children can be expected to have until they reach such an age of discretion that they can refrain from opening the cover because they know enough not to do so. 
     The cover can be removed completely from the receptacle plate if desired, as when its protective function is no longer required, simply by lifting the open cover to disengage the hinge pins on the cover from the sockets on the plate. 
     The electrical receptacle safety covering of this invention does not require any unusual material or method of manufacture. It preferably is made of electrically non-conductive thermosetting or thermoplastic composition, as by injection molding or other suitable process. Acceptable compositions include polyvinyl chloride, nylon, polypropylene, bakelite, and hard rubber, for example. Wood, glass, and ceramic materials also may be used satisfactorily. 
     Some variants of the preferred embodiment have been suggested above. Other modifications may be made, as by adding, combining, deleting or subdividing parts or steps, while retaining at least some of the advantages and benefits of the present invention, which itself is defined in the following claims.