AU634462B1

AU634462B1 -

Info

Publication number: AU634462B1
Application number: AU2627192A
Authority: AU
Priority date: 1992-10-08
Filing date: 1992-10-08
Publication date: 1993-02-18
Anticipated expiration: 1998-10-08

Description

I I_ 634462

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT Name of Applicant(s): Actual Inventor(s): Address for Service: ROSS DOUGLAS SHIELD ROSS DOUGLAS SHIELD CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

I I Invention Title: SAFETY ELECTRICAL OUTLET The following statement is a full description of this invention including the best method of performing it known to me:

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THIS INVENTION relates to electrical outlets and is particularly concerned with faceplates for such outlets having associated safety features to prevent direct access to the outlets.

There are a number of devices presently available on the market to prevent children from accidentally electrocuting themselves by inserting metallic objects through the faceplates of electrical outlets. The most commonly available devices are thin plastic plugs having plastic prongs which are inserted through the prong receiving openings and left in situ until the electrical outlet is to be used. The plugs can only be removed by the use of a key which comprises a T-piece on a manipulable ring. The T-piece is inserted into a groove in the outer facing portion of the plastic plug, rotated, and then moved outwardly to extract the plug.

While such devices are effective, they have the disadvantage that the key can become misplaced or be housed in an inconvenient location, resulting in frustration in the person wanting to use the electrical outlet. Furthermore, when such outlets are in use, the plugs tend to be left lying around or lost, or are a general nuisance in allocating them a place so that they can be readily retrieved when required.

It is therefore an object of the present invention to provide an effective safety device for faceplates of electrical outlets which does not have the aforementioned disadvantages.

According to the present invention, there is provided a faceplate for an electrical outlet having at least one set of openings for receiving prongs of an electrical ~_ii I _C plug, said faceplate including a shutter having apertures to enable insertion of the prongs of an electrical plug therethrough when the apertures are in alignment with the openings in the faceplate, spring means for normally biasing the shutter into a closed position whereat the apertures are out of alignment with the openings, and button means carried by the shutter for manually sliding the shutter from its closed position to an open position against the force of the spring means whereat the apertures are in alignment with the openings.

Preferably, a lug is provided on the shutter to coact with a switch on the electrical outlet, to prevent the switch from being roc,,ed to an on position when the shutter is S in a closed position; thus providing an additional safety feature.

The button means is suitably formed integrally with the shutter and projects, in use, upwardly through an opening in the top edge of the faceplate, perpendicular thereto. Such a location enables manipulation of the button means by exerting a downward pressure on the button with a finger to slide the shutter open. Such pressure must be maintained until a plug is inserted through the aligned apertures and openings, at which point the pressure can be relieved.

In order to ensure that the button means cannot be readily manipulated by young children, the spring is chosen to have a tension that requires considerable pressure to overcome before the button and shutter can be slid to an open position.

The spring tension will not, however, be so great as to prevent relatively easy manipulation by an adult.

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Il ~F 4 The shutter is located in the normal cavity between the faceplate and the electrical outlet and is fabricated from a non-conductive rigid material such as polypropylene, polyethyltetraphthalate, polyvinylchloride or like plastics material. The rigidity of the material is a desirable property to ensure that the shutter can be slid into and out of the closed position without bending and, more importantly, to ensure that it cannot readily be pierced by a sharp implement pushed through the prong receiving openings of the faceplate. A typical thickness for the shutter will generally be in the range of 2-4 mm but will obviously be selected accordingly to the rigidity and pierce resisting characteristics of the material from which the shutter is fabricated. A limitation on this thickness will, however, be imposed by the cavity dimensions within the faceplate and for S, standard faceplates this may be of the order of 5 mm.

The spring means may be housed internally or externally of the faceplate. Most preferably, it is located externally of the faceplate, between the button and the edge of the electrical outlet. In order to retain it in position, a housing may be formed in the upper portion of the button into which the spring extends. The spring means is suitably a tensioned coil spring of approximately 5 mm in diameter and about 20 mm in length in its untensioned state.

A collar may be located around the opening in the faceplate through which the button projects. The collar will suitably be closed on three sides and open on the rear side to enable the faceplate to be removed without having to simultaneously remove the shutter. The main purpose of such a collar is to provide an aesthetically pleasing finish to the product and to simultaneously prevent removal of the spring means from under the button.

The spring biased shutter arrangement of the invention provides an effective method for preventing young children from being electrocuted by playing with electrical outlets. The operation of the arrangement requires two hands to be used simultaneously, the one applying a pressure on the button to move the shutter to an open position, and the other inserting the electrical plug when the open position has been reached. That is, the combination of two-hand co-ordination and downward pressure is something which young children cannot ~achieve.

4 The invention also overcomes the problems of the aforementioned safety devices in not requiring a key and extra items to be used to effect blocking and unblocking of the outlet.

In addition, it will be readily apparent that the use of a shutter can make the requirement for a switch to be optional.

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a front view of an electrical faceplate showing the shutter mechanism in a closed position; Figure 2 is a front view of the same faceplate as shown in Figure 1 but with the shutter mechanism in an open position; Figure 3 is a side elevation of the faceplate of 4-~flrnrz~ 6 Figure 1 including an electrical outlet and a cut-away plug in phantom; Figure 4 is a side elevation of the faceplate of Figure 2 in phantom including an electrical outlet and a cutaway plug; and Figure 5 is a partial front perspective view of a shutter according to the present invention.

In all the drawings, like reference numerals refer to like parts.

Referring to Figure i, a faceplate for a single electrical outlet is depicted generally at 10. The design of the faceplate is not important and will vary according to aesthetic and regulatory requirements, and the number of outlets to be incorporated at a single location. The faceplate may be a standard plastic moulded unit which is similar to those in common use.

The faceplate houses a shutter 11, fabricated from 2mm thick polyethyltetraphthalate, which is shaped to fit between the internal configurations associated with the electrical outlet and faceplate, and to be slidable in a a vertical manner therein. The shutter includes three apertures 12, 13, 14 through which the prongs of a plug may be inserted when the apertures are brought into alignment with the openings 15, 16, 17 in the faceplate.

The shutter includes an integral lug 18, which is located beneath the on/off switch 19 when the switch is in a normally "off" pcsition, and an integral button 20 which projects upwardly through the upper portion of the faceplate.

The button has an internal housing 21 which retains a coil __i spring 22 in a vertical position against the casing of the electrical outlet. The coil spring biases the shutter upwardly so that the holes and apertures are normally out of alignment so that a plug cannot be inserted and the switch cannot be rocked to an on position.

A collar 23 is formed around the spring and button for aesthetic purposes and to ensure that the spring cannot be removed.

Figure 2 shows what happens when downward pressure is applied to the top of the button 20. The button is shown depressed fully into the collar 23 with the coil spring 22 compressed. As the shutter 11 moves downwardly, the apertures in the shutter are brought into alignment with the openings in the faceplate. A plug can now be fully inserted and the switch 19 rocked into an "on" position.

It will be noted that pressure must be continually applied to the button by one hand until the plu* is inserted by the other hand or else the apertures and holes will not be maintained in alignment. Such dexterity is not something which young children are capable of, and the safety feature of the arrangement is immediately apparent.

Figure 3 illustrates how the prongs 30, 31 of a plug are prevented from making electrical contact with the contact 6Y plates 32, 33 of the electrical outlet. The prongs can only be inserted through the openings in the faceplate and are prevented from further insertion by the shutter 11 which extends over the electrical contact plates.

Figure 4 shows the alignment of the apertures 13, 14 with the openings 16, 17 to enable the prongs 30, 31 of the

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8 plug to be inserted therethrough so as to make electrical contact with the contact plates 32, 33. The drawing also shows how the switch can be rocked to an "on" position (see heavy arrow).

Figure 5 shows the shutter 11 in detail, with integral button 20 and integral lug 14. It will be appreciated that the shutter is of a significant rigid structure and cannot be pierced by sharp implements.

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Claims

2. A faceplate as claimed in claim 1 and including a lug on the shutter which is adapted to co-act with a switch on the electrical outlet to prevent the switch from being rocked to an on position when the shutter is in a closed position.
3. A faceplate as claimed in claim 1 and substantially as herein described in the accompanying drawings. DATED this 8th day of October 1992 ROSS DOUGLAS SHIELD By his Patent Attorneys CULLEN CO. ABSTRACT A safety arrangement for electrical outlets to prevent young children from being electrocuted. The arrangement comprises a shutter (11) which slides within a faceplate (10) of the outlet. The shutter has apertures (12, 13, 14) to enable the insertion of prongs of an electrical plug when the apertures are in alignment with openings 16, 17) in the faceplate. Spring xveans (22) are provided to bias the shutter into a normally closed position at which the apertures are out of alignment with the openings. Button means (20) on the shutter enable the shutter to be slid to an open position against the force of the spring means, at which the apertures are brought into alignment with the openings and an electrical plug can then be inserted.