US3159446A

US3159446A - Pilferproof wall plate

Info

Publication number: US3159446A
Application number: US151691A
Authority: US
Inventors: Donald E Protzmann
Original assignee: General Time Corp
Current assignee: General Time Corp
Priority date: 1961-11-13
Filing date: 1961-11-13
Publication date: 1964-12-01
Anticipated expiration: 1981-12-01

Description

Filed Nov. 13, 1961 .INVEVTOR. Dmmw Efiwrzmmw United States Patent 3,152,445 I meanness WA L PLATE Donald E. Protzmann, Athens, Ga, assignor to General Time CorporatioiifNew Yo'rl'r, N.Y., acorporation of Delaware Filed Nov. 13, 1961, Ser. No. 151,691 1 Claim. (6i. 339-82) This invention relates to electrical appliance plug and socket connections and more particularly to a securing assembly for locking the plug and socket together.

The conventional appliance is provided with a cord carrying a plug which can be easily inserted in a socket of an electrical receptacle to provide power for the appliance and can also be easily removed. Consequently, convenient portability of the appliance is achieved. This portability isnot an advantage, however, in some respects.

First, an appliance used in a hotel, motel or the'like,

where transient guests stay, can be easily pilfered if all that need be done in moving the appliance is to unplug it. Additionally, since the ordinary plugs are made easily removable they can come part way out of a socket and leave exposed, current conducting prongs to be touched and thereby injuring persons, especially children. Furthermore, a plug may be accidentally unplugged where removing power from the appliance is detrimental as with a freezer or sump pump.

It is an object of the present invention to provide a securing assembly for an appliance cord which will secure a plug carried by the cord to a plug receptacle or outlet socket. It is an additional object to provide such a securing assembly which can be used with conventional elec trical receptacles and appliance cord plugs, which has an attractive outward appearance, and in which the guard the above type which is simple and incxpensive to manufacture and easily installable.

Other objects and advantages of the invention will become apparent upon reading the following detailed de scription and upon reference to the drawings in which:

FIGURE 1 is an exploded view showing the escutcheon plate constructed in accordance with the present invention;

FIG. 2 is avertical section showing the escutcheon'plate installed; and

FIG. '3 is an enlarged face view of the head for the fastening screw. I

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to such embodiment, on the contrary, it is intended tocover all alternatives, modifications. and, equivalents, falling withinthe spirit and scope of the invention as defined by theappended claim. Turning to the drawings, shown inFlG. 1 is an exem plary embodiment of the present invention asused with an appliance, in the present instance an electric clock 1%. The clock Ill is energized from a common duplex receptacle ill-having

electrical sockets

12 and 13. The receptacle 11 is installed in the usual manner within an outlet boxld mounted in the wall 15. The receptacle ll is provided with a threadedaperturc -16 used for securing the usual wall plate. I Y

The clock 10 is portable having a cord 18 on the end of which is a two-prong plug 19. The latter'is preferably constructed of molded rubber, plastic, or the like with the prongs electrically conductive and adapted to slidably fit into either of the

outlet sockets

12, 13.

For securing the plug 19 inv electrical engagement with i one of the outlet sockets, here chosen as outlet 12, a securing assembly 20 is provided. "The assembly 20 ineludes an escutcheon plate 21' and appropriatefastening ice . 2 means cooperating with the plate. In the present instancethe latter function is performed by a screw 22 re ceived in a plate opening 245 and threaded lnlhe threaded aperture 16.

In accordance with the present invention the escutcheon plate 21 is secured to the receptacle 11 sons to lock the plug 19 in electrical engagement with the outlet socket 121. In the present instance, locking of the electrically engaged plug is achievedby installing the escutcheon plate 21 tocover the plug and thereby prevent the removal of the plug 19 fromthe socket l2. Explaining the escutcheon plate construction in further detail, the plate is provided with a cup portion 25 for enclosing the electrically engaged plug i9. So that the plate 21 installs flat against the wall lithe cup portion 25 is sufiiciently deep to receive plugs of common sizes. Provided in the cup portion 25' is an opening 25'0 for receiving the cord 18. This opening is dimensionally chosen so as to allow the cord 13 to slip through, but restricting the passage of the plug therethrough. Sliding wear is reduced and closer fit is achieved between plate 21 and cord 18, by providing a bushing 26 having a smooth inner circumference. When'the escutcheon plate 21 is fastened in place it overlies and shields the electrically engaged plug 19. It will be appreciated that pulling oi the cord will not disengage the plug because the escutcheon plate restrains the attached plug; I

For locking the escutcheonplate 21 and plug 19 togethen the plate'fastening screw 22 is constructed with a non-backout head 28. lA s can be best seen in FIG. 3,

the .screwhead-Zii has ascrewdriver slot 29 of the -ordi-.

nary type except for the diagonally opposite

half sides

30, 31. of the slot being chaxnfered or beveled. The charnfering is done so that asorewdriver or the like can be used to tighten the screw 22, but the same implement is ineffective to back out the screw. Therefore as long as the appliance and its attendant cord and plug are intact, the appliance cannot be carried away.

Further explainingthe construction of the escutcheon plate 2i, it has a socket aperture 32 so that it can replace I honesty. v I

Furthermore, since the plugl9 cannot be disengaged I from the socket 12 Without removal of the escutcheon plate, accidental removal, of power is prevented from freezers, sump pumps and such appliances where power removal is' undesirable; Also, sincethe plug and socket are enclosed, partial removal or" plug prongs from the socket is prevented and thereby the risk arising from'ex posed current carrying conductorsis eliminated. These advantages are achieved with the present invention while maintaining simplicity and economy of manufacture.

I claim as my invention: l

A securing assembly for an electrical cord. having a plug at one endand an appliance at the other end, the plug being adapted for electrical engagement with an outlet socket of a receptaclehaving a tapped opening formed therein, said assembly comprising, in combination, an escutcheon plate provided with a first opening surrounding the receptacle outlet socket permitting the plug to be receptacle, for anchoring said plate to said receptacle, said screw having a non-backout head, a cup formed integral it Patented, Dec. 1, 1964.

with the escutcheon plate, said cup being displaced lateral- 1y from said screw and projecting outwardly in overlying relationship with the receptacle outlet socket and enclosing the plug, said cup having a single substantially central opening for receiving the cord, said cup substantially restricting the plug against movement in a direction tending to disengage or remove the plug from the socket to effect anti-pilfer electrical connection of the appliance.

References Cited in the file of this patent UNITED STATES PATENTS Brooks Oct. 1, 1873 Leopold Feb. 22, 1949 Holtshouser May 24, 1955 Grimes 1- June 16, 1959 Tiikkainen Apr. 26, 1960 Marbais June 6, 1961