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Publication numberUS3775729 A
Publication typeGrant
Publication dateNov 27, 1973
Filing dateMay 1, 1972
Priority dateMay 1, 1972
Publication numberUS 3775729 A, US 3775729A, US-A-3775729, US3775729 A, US3775729A
InventorsCasper R
Original AssigneeCasper R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Safety cord plug adaptor for electric outlet boxes
US 3775729 A
A safety protective cover for electrical wall outlet includes hollow housing, and means for releasably affixing same over at least one plug-in receptacle of outlet with plug-in electric cord extending from housing. Stop means on cord and housing, after plugging cord in receptacle and subsequent attachment of housing to wall outlet, effective independently of the plug to prevent unplugging of the same due to a child tugging on the cord.
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Description  (OCR text may contain errors)

United States Patent [191 Casper Y Nov. 27, 1973 [76] Inventor:

[ SAFETY CORD PLUG ADAPTOR FOR ELECTRIC OUTLET BOXES Raymond C. Casper, 1655 West Market St reet, Stow, Ohio 44. .1.3.

[22] Filed: May 1, 1972 [211 App]. No.: 249,079

[56] References Cited UNITED STATES PATENTS 2,415,602 2/1947 Monaco 339/77 2,526,606v 10/1950 Gregg...

2,942,226 6/1960 Low. 33 9/75P c /9 I T E /6 ll 12/1962 Thaw 339/39 12/1964 Protzmann 339/82 .Primary Examiner.loseph H. McGlynn AttorneyWilliam Cleland [5 7] ABSTRACT A safety protective cover for electrical wall outlet includes hollow housing, and means for releasably affixing same over at least one plug-in receptacle of outlet with plug-in electric cord extending from housing. Stop means on cord and housing, after plugging cord in receptacle and subsequent attachment of housing to wall outlet, effective independently of the plug to prevent unplugging of the same due to a child tugging on the cord.

6 Claims, 5 Drawing Figures SAFETY CORD PLUG ADAPTOR FOR ELECTRIC OUTLET BOXES BACKGROUND OF INVENTION l-leretofore, protective covers for electrical outlets have been suggested in the prior art, ostensibly for the purpose of preventing small children from removing extension cord plugs from the outlets by pulling on the cords. Such devices of known types, however, have failed as safety means because,'by relatively slight pulling effort applied to a cord, the lug thereon could be pulled from the electrical receptacle, and/or entirely separated from the plug with resultant possible danger of electrical sparking and/or electrical shock. Some such devices provided in connected segments were capable of accidental separation in use, and/or were difficult and expensive to manufacture.

SUMMARY OF DISCLOSURE According to the present invention, the improved protective cover includes a one-piece housing which may be provided with spaced generally cup-shaped parts, each extending from a flat base member provided with attachment means for affixing the same to an electrical wall outlet with said cup-shaped housing parts in cupped relationship over plug-in receptacles of known types on the outlets. Each said housing part may be provided with aperture means in a peripheral wall portion thereof near the base memberthereof, andextending into said base member, if necessary, for insertion of acord plug inwardly through such aperture means while the housing is free of 'wall outlet. Slot means also may be provided in said peripheral wallportions of the respective housing parts to communicate with said aperture means thereof, andextend to outer end walls of the respective housing parts for permitting radially inward passage of the cords to extend through the respective end wall portions,-whereby saidhousing can be attached to the wall outlet as a unit to have the cords extended from the respectiveend wall portions subsequent to attachment of the cord plugs to the respective fixed receptacles. Adjustable stop means is provided within each saidhousing partfor restraining outwardly by-applied tension on the cord which otherwise would be likely to effect unwanted removal of the plug from the wall outlet. In other words, themain purpose of the present invention is to prevent the cords from being unplugged from thewall outlets without first removing the adaptor from the same.

A general object of the present invention is to provide a unitary protective cover of the character described which can only be removed froma wall outlet by a relatively mature person, and in which means is provided to prevent small children from unplugging extension cords from the wall outlet by tugging or pulling on the cord.

Another object of the invention is toprovide a protective cover of the character described which lends itself to economical production, such as by use of a two-piece sectional cavity mold.

Other objects of the invention will be manifest from the following brief description and the accompanying drawings.

Of the accompanying drawings:

FIG. 1 is a front elevation of a molded protective cover, partly broken away and in section,.embodying the features of the invention and illustrating thecover in position for screw attachment thereof to a wall to overlie an electrical wall outlet, with pronged plugs of extension cords inserted into plug-in outlet receptacles in known manner.

FIG. 2 is a horizontal cross-section, on the same scale, taken substantially on the line 2-2 of FIG. 1, and illustrating the manner of insertion and removal of a cord plug by means of chain-dotted and full lines.

FIG. 3 is an end elevation of the protective cover as viewed from the right of FIG. 2, and on the same scale.

FIG. 4 is a perspective view of a stop member for selective attachment to an extension cord, and interlocking reception within hollow portions of the protective cover.

FIG. 5 is a perspective view corresponding to FIG. 4, illustrating a modified form of stop member in selective fixed attachment to an extension cord. 7

Referring to the drawings generally, and to FIGS. 1 to 3 in particular, the numeral 10 designates a onepiece protective cover, of hard molded plastic for example, adapted for fixed attachment to an electrical outlet E in a wall W, the outlet being of known type usually provided with two spaced plug-in receptacles R. The cover 10 includes a rectangular base plate 11, adapted to overlie the outlet E, and spaced cup-shaped housings 12, 12integral with the plate 11 for presenting hollow chambers 13, 13 of the housings in overlying communication with the spaced receptacles R. The cover 10 may be secured to the outlet E by means of a screw 14 adapted to be inserted through an aperture 15 in the base plate 11, at a point centrally thereof between the housings'l2, and threaded into the electrical outlet 3 in known manner as best shown in FIG. 2.

Each cup-shaped housing part 12 may be of molded rigid plastic, in the shape of a frustum of a pyramid for example, to have four connecting side walls 16, 16 defining the chamber 13, which is closed by a top wall 17, The wall 16 of each housing 12, at corresponding ends of the plate 11, may have therein an aperture 18, which can'be extended into the plate 11 if necessary, through which aperture a pronged plug P on an electric extension cord C may be inserted, as indicated in chaindotted lines in FIG. 2, prior to securing the cover 10 to the outlet E. i

Stop means maybe adjustably affixed or provided on the respective cord C, after it is passed through the aperture l8 and after the plug P is plugged into an outlet R, to be engageable with upper portions of the housing 16, and thereby prevent withdrawal of the cord beyond a given extent thereof. For this purpose, a cube-shaped block 20 of suitable material, such as hard plastic,.may be provided with angular slot means extending part way through the block, generally as shown in FIG. 4, and

defining angularly disposed, passage wall means, for I adjustable zig-zag distortion wedging reception of the cord C through the block 20, as shown in FIG. 2. When the cord is selectively and fixedly adjusted on the block, the cord plug P is adapted to be plugged into the respective receptacle R, after which the protective cover 10 may be positioned on to the outlet E and attached thereto by means of the screw 14. When so positioning the cover 10, the stop block 20 is easily adjustable into full seating thereof within a complementally shaped recess 21 in the respective housing part 12.

Other stop means may be employed in place of the cube shaped block 20, such as a three-pronged E- shaped stop 23 as shown in FIG. 5. The device 23 would be wedgingly adjusted on the cord C, by looping the cord as before, to prevent extension of cord C through the top wall 17 of the respective housing part 12. The stop 23, like the stop 20, may be proportioned for either loose or wedging reception in the housing recesses 21, so long as the stop prevents removal of the cord plug P from the receptacle R and/or separation of the cord C from the plug P. The same apertured housing walls 16 may also have a narrow slot 19 therethrough, extending from the respective apertures 18 to the center of the corresponding top wall 17. This arrangement is such that, with the protective cover unattached with reference to the wall outlet E, the plug P can be readily inserted through the aperture 18 of a housing part 12, after which the cord C can be passed through the connecting slot 19, to permit extension of the cord through the top wall 17 as shown in FIGS. 1 to 3.

In use of the protective cover 10 described above to prevent a small child from pulling the extension cords C from receptacles R of the electrical outlet E, the cord plugs P are inserted endwise through the'apertures 18, prior to attachment of the cover to the outlet, as shown in chain dotted lines in FIG. 2. The cube-shaped stop members 20, are then wedgingly affixed to the cords C in closely spaced relationship to the plugs P, as previously described and then the plugs are forcibly inserted into the receptacles R, in known manner.

Next, with the plugs P so inserted, the cords C are fed into the slots 19 and drawn upwardly until the stop members 20 are complementally received and seated within the recesses 21 when, at the same time, the plate 11 is seated over the outlets E, as shown in FIGS. 1 to 3, whereby the cords C extend freely axially outwardly of the free ends of the respective housing parts, as shown in full lines in FIGS. 1 to 3. Upon accomplishing this positioning of the protective cover 10, it is readily secured firmly against the wall W, by means of the screw 14 as shown in FIG. 2.

With the protective cover 10 so affixed, a small child, upon pulling or tugging on a cord C, can only meet with resistance of the anchored stop 20 (or 23), without affecting the plugged-in condition of cord plug P. Accordingly, the present invention obviates the previously experienced danger of a small child being able to unplug an extension cord by tugging on the same.

Modifications of the invention may be resorted to without departing from the spirit thereof or the scope of the appended claims. As an example, it is readily apparent that the stop means 20 and 23, shown in FIGS. 4 and 5, may be supplanted by means oftight knots tied peripheral and outer-end wall portions; means on said housing for affixing the same to thewall at the outlet with a said cup-shaped part in cupped relationship over a said receptacle; aperture means provided in said cupshaped part adjacent the inner end thereof for wedging reception of a 'co'rd plug inwardly therethrough while the housing is" free of the wall outlet; slot means provided' in the wall portions of said cup-shaped part to communicate with said aperture means and extending to a said outer end wall, for permitting inward passage of the cord to extend through said outer-end wall portion, whereby said housing is attachable to the wall outlet with the cord extended from the end wall portion, subsequent to attachment of the cord plug to the fixed receptacle; and stop means adapted to be carried by a portion of said cord within said cup-shaped part for engagement with said outer-end wall portion for restraining outwardly applied tension on the cord which would otherwise tend to effect removal of the plug from the wall outlet, said stop member having staggered portions for wedging reception of the cord.

2. A cover for a wall outlet as in claim 1, wherein said stop member is shaped for snug complemental reception in the hollow of said cup-shaped part, said stop member having irregular passage means extending inwardly of a side thereof for adjusted inward wedging reception of the cord therethrough.

3. A cover for a wall outlet as in claim 1, the hollow of said cup-shaped part terminating in a seat portion for stop reception of said stop member affixed on the cord.

4. A cover for a wall outlet as in claim 3, said stop member and said seat portion being shaped for snug complemental reception of the stop member in said seat portion.

5. A cover for a wall outlet as in claim 4, said stop member being a cube-shaped block and said staggered portions thereof defining angularly disposed connecting passages in which the cord is wedgingly gripped.

6. A cover for an electrical wall outlet as for locking attachment of an electrical extension-cord plug to a rein the cords C per se requisitely spaced from the plugs I P'to be in stop engagement with the outer walls 17 of tions defining a zig-zag passage for tight zig-zag wedging for reception of a portion of the extension cord to extend outwardly from the hollow of the housing, thereby to anchor the cord to the housing against removal of the plug from the receptacle as by pulling action applied to the cord.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2415602 *Mar 16, 1944Feb 11, 1947Monaco George CGuard for flush wall outlets
US2526606 *Aug 30, 1947Oct 17, 1950Gregg Hendrick JProtective cover for electrical outlets
US2942226 *Oct 21, 1958Jun 21, 1960Fahy Baker LowProtective cover for appliance plugs
US3067402 *Apr 5, 1961Dec 4, 1962Norrich Plastic CorpSafety plug lock
US3159446 *Nov 13, 1961Dec 1, 1964Gen Time CorpPilferproof wall plate
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4045108 *Jan 31, 1977Aug 30, 1977Olsen Emil MSpring retainer for electric plugs
US4066313 *Aug 3, 1976Jan 3, 1978Von Dem Hagen TronjeSafety guard for electrical plugs
US4083618 *Jun 6, 1977Apr 11, 1978Busch Jr Francis WSafety enclosure
US4815837 *Nov 25, 1987Mar 28, 1989Murakami Kaimeido Co., Ltd.Actuator unit housing for rearview mirror
US5044976 *Oct 22, 1990Sep 3, 1991Thompson Dennis LElectrical cord holding device and method for using same
US5072071 *Jul 19, 1989Dec 10, 1991Square D CompanyWire clamp assembly for an electrical load center
US5547390 *Jan 17, 1995Aug 20, 1996Laherty; Mark E.Electrical plug securing device
US5562488 *Mar 1, 1995Oct 8, 1996Neiser; GabeModular outlet assembly
US5713758 *Aug 1, 1996Feb 3, 1998Black & Decker Inc.Cordlock retention
US5795176 *Aug 14, 1996Aug 18, 1998Blaetz; EwaldMethod of protecting an electrical connection and plug lock therefor
US5944542 *Jun 27, 1997Aug 31, 1999Han Y. LeePlug safety adapter for anti-electric shock
US6491539Jul 25, 2001Dec 10, 2002Jeff JohnstonElectrical plug retainer
US7455546Aug 28, 2007Nov 25, 2008Unisys CorporationElectrical power strip plug retention
US7517221Jul 27, 2007Apr 14, 2009David W ChidakelVertical extender for an electrical outlet which protects pets and children from shock hazards
US7517235Dec 28, 2006Apr 14, 2009General Electric CompanyPress fit connection for mounting electrical plug-in outlet insulator to a busway aluminum housing
US8986040Apr 24, 2013Mar 24, 2015Nuk Usa LlcChild safety plug lock
US9147973 *Sep 11, 2013Sep 29, 2015Michael W. MadisonEnclosure for wall charger
US9197018Oct 28, 2013Nov 24, 2015Nuk Usa LlcChild-resistant plug
US9350150 *Mar 13, 2014May 24, 2016Necia Clark-MantleCasing system with cable retainer for electronic device chargers
US20090211026 *Feb 26, 2008Aug 27, 2009Robert SchoffMedical transport safety apparatus with lighting system
US20140263869 *Mar 13, 2014Sep 18, 2014Necia Clark-MantleCasing system with cable retainer for electronic device chargers
WO1995006343A1 *Aug 22, 1994Mar 2, 1995Nokia Telecommunications OyA locking device for an electric cable
U.S. Classification439/459, 439/371, 174/67
International ClassificationH01R13/639
Cooperative ClassificationH01R13/6395
European ClassificationH01R13/639D