GB2038112A

GB2038112A - Improvements in or relating to automatic locking electrical socket outlets

Info

Publication number: GB2038112A
Application number: GB7929172A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-08-22
Filing date: 1979-08-22
Publication date: 1980-07-16
Also published as: NO792675L; SE7906971L; DK348979A; DE2933625A1; FR2435833A1; NL7906067A; IT7968699A0

Abstract

An automatic locking outlet is provided for use as an electric mains wall socket. The socket comprises a front plate 1 and a slider 3, each of which has formed therein holes 9 for the passage of pins of a mains plug. The slider 3 is slidable from a first position, in which it covers the outlet holes (as shown), to a second position, in which the slider holes and outlet holes are aligned by pushing with the plug pins against the action of a spring 7. Two spring-loaded slidable locking pins 12 enter the holes in the slider 3 when in the first position to lock it in this position. When a plug is inserted, the pins thereof push the locking pins out of the hole to allow the slider 3 to be moved to its second position and the plug pins to enter the outlet holes. When no plug is inserted, there is no access to the outlet holes, thus improving the safety of the outlet. <IMAGE>

Description

SPECIFICATION Improvements in or relating to automatic locking electrical socket outlets The invention relates to an automatic locking safety electrical socket outlet and, more particularly, to a safety outlet with a slider automatically locking in the safety position when the outlet is not in use.

As is known, there are many types of safety outlets available which, however, are not easy to use. Many such outlets do not have satisfactory strength and do not present the required safety because their design leaves gaps which allow penetration of small pointed articles, so that the chances of accident are thus not eliminated.

According to the invention there is provided an automatic locking electrical socket outlet, comprising a front plate provided with a slider having holes corresoponding to the contact pins of a plug, the slider being slidable from a first position, where it covers completely outlet holes in the front plate through which the plug contact pins can pass, to a second position, where the holes of the slider are aligned with the outlet holes, the slider being urged towards the first position by a spring so that movement of the slider from the first position to the second position is achieved against the action of the spring and the slider returns automatically to the first position under the action of the spring upon removal of the plug from the outlet.

It is possible to provide an automatic locking outlet which is easy to use, has increased strength, is simple in construction, substantially eliminates accident hazards, allows firm fitting with the associated plug-so that, the creation of an arc between the contacts being substantially eliminated, the life of the outlet is extended-and can be manufactured at low cost, only slightly higher than that of known outlets.

Such an automatic locking outlet is suitable for use, not only where safety requirements render its installation necessary, but also in every case, being suitable for superseding the known wall outlets.

In a preferred embodiment of the invention, the slider is disposed on the front plate of the outlet, the slider having three holes allowing passage of the contact pins of a plug and being retained by the spring in the first position in which it covers completely the openings in the main outlet and it does not allow access in the interior thereof. Two locking pins are provided to lock the slider, the locking pins extending within the holes of the slider, when the latter is in the first position, blocking movement thereof. When the plug is placed into the holes of the slider and it is pressed, it pushes the locking pins backwards against springs and unlocks the slider.Unlocking can be effected only by placing the plug in position and by pushing both locking pins simultaneously, as pushing only one locking pin does not unlock the slider, accident hazards thus being substantially eliminated.

Plug movement forces the slider to slide, against the spring, to the second position, where the holes of the slider are in alignment with the outlet holes, so that the plug contact pins can penetrate into the outlet and electrical contact can be effected. To facilitate sliding, a guide is provided within the third contact pin of the plug slides. In this second position the slider, under the load of its associated spring, clamps the plug contact pins, retaining the plug in a firm fitting with the outlet. Thus, the creation of an arc between the plug contact pins and the outlet contacts is avoided, which results in a considerable increase in the life of the outlet.Upon removal of the plug, the slider, pushed by its associated spring, returns to the first position and the locking pins, pushed by their associated springs, lock the slider in position, locking in safety position being thus achieved automatically.

Movement of the slider from the first to the second position can be vertical, horizontal or in any other direction, as well as from down upwards, from right to left and vice versa.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a front view of a preferred safety outlet; Figure 2 is a section taken along the line XYZO of Fig. 1; Figure 3 is a back view of a front plate of the safety outlet; Figure 4 is a section taken along the line AB of Fig. 3; Figure 5 is a front view of a fitting member; Figure 6 is a section of the fitting member along the line CD of Fig. 5; Figure 7 is a front view of a slider; Figure 8 is a section of the slider taken along the line EZ of Fig. 7; and Figures 9 to 1 5 show views and sections of the remaining components of the preferred automatic locking outlet.

A front plate 1 has in its back surface a rectangular recess 2, in which a slider 3 can slide. The plate has also a rectangular opening 4 into which a rectangular protrusion 5 of the slider 3 can slide. A thin cylindrical pin 6, integral with the slider, is provided in the upper part of slider 3 at the mid-point of its edge, which pin penetrates into a spring 7.

Correspondingly, in the upper part of the recess of the plate 1, a channel 8 is formed into which the spring 7 enters and is retained in position. Thus, the slider 3 can slide in the recess 2 against the spring 7, from a lowest position, where the bottom edge of the slider abuts on the bottom edge of the recess, up to the highest position, returning to the original position by the spring 7 automatically.

Three holes 9 are provided in the rectangu lar protrusion of the slider corresponding to the contact pins of a three-pole plug.

The corresponding holes for the passage of the plug contact pins through a fitting mem ber 10 and an outlet body 11 are located so that their axes coincide with the axes of the holes 9 only when the slider is in the upper position. Accordingly, the plug contact pins can pass through the holes of the slider, the fitting member and the body for effecting electrical contact only when the slider is in its upper position.

The arrangement described so far consti tutes an automatic safety outlet. It is possible, however, for a small child to shift the slider by means of a pointed article, which can then penetrate into the holes causing an accident.

To avoid such an eventuality and to provide effective complete safety, the outlet comprises two locking pins 1 2 which can slide back and forth within holes 1 3 in the fitting member 10. The pins 1 2 (see Fig. 12) are of cylindri cal shape and have at one end thereof a shoulder 14. The holes 1 3 have at their one end a corresponding rim on which the associ ated pin shoulder stops, so that the pin 1 2 cannot come out from the hole 1 3. The pins 1 2 are hollow and they have in their cavities springs 1 5 which rest on the surface of the body 11 when the outlet is assembled.Thus, the pins are continuously under spring load, so that they protrude out of the front surface of the fitting member 10. The positions of the holes 1 3 bearing the pins 1 2 are such that the axes of the holes 1 3 coincide with the axes of the holes 9 of the slider 3, through which the plug contact pins pass, when the slider is in the lowermost position, in which case the pins 1 2 pushed by the springs 1 5 can enter into the holes 9 and the slider is locked in this position. A guide 1 6 in the fitting member 10 facilitates sliding of the slider when the latter is moved by the plug.

The plate 1, the fitting member 10 and the body 11 are provided with the necessary formations and fittings for assembling the outlet, placing it in position and coupling it to an electrical (mains) network.

The overall design and materials are the ones used in known wall outlets. The slider and the locking pins are made from similar material such as bakelite or special plastics material.

Claims

1. An automatic locking electrical socket outlet, comprising a front plate provided with a slider having holes corresponding to the contact pins of a plug, the slider being slida ble from a first position, where it covers completely outlet holes in the front plates through which the plug contact pins can pass, to a second position, where the holes of the slider are aligned with the outlet holes, the slider being urged towards the first position by a spring so that movement of the slider from the first position to the second position is achieved against the action of the spring and the slider returns automatically to the first position under the action of the spring upon removal of the plug from the outlet.

2. An automatic locking outlet as claimed in claim 1, wherein the slider is arranged to slide in a vertical direction.

3. An automatic locking outlet as claimed in claim 1, wherein the slider is arranged to slide in a horizontal direction.

4. An automatic locking outlet as claimed in claim 1, wherein the slider is arranged to slide in an oblique direction.

5. An automatic locking outlet as claimed in any one of claims 1 to 4, further comprising two locking pins slidable reciprocatingly within holes provided in the outlet and urged by springs, the locking pins being arranged to enter into the holes of the slider when the slider is in the first position for locking the slider in this safety position, the slider being arranged to be unlocked only by penetration of the plug pins into the holes of the slider, whereby under the pressure of the plug contact pins the locking pins recede releasing the slider, which then can be moved to the second position, the slider being locked automatically when it returns to the first position upon removal of the plug.

6. An automatic locking outlet as claimed in any one of the preceding claims, in which, when fitted with the plug, the spring urges the slider so as to clamp the plug making the plug-outlet fitting firm.

7. An automatic locking electrical socket outlet substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.