GB2312795A

GB2312795A - Infant proof mains plug and socket

Info

Publication number: GB2312795A
Application number: GB9609402A
Authority: GB
Inventors: Duncan Shirreffs Bain
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-05-01
Filing date: 1996-05-01
Publication date: 1997-11-05
Also published as: GB9609402D0

Abstract

A mains plug and socket with provision for securing the plug to the socket in order to prevent unwanted disconnection. The plug and socket may be secured using a screw or bolt. The screw may be of a special security type requiring a special tool or key to unscrew it. Alternatively, the apparatus may be securing with a key operated lock.

Description

Title Infant-proof mains plug and socket 1 Background 1.1 This invention relates to an electricity mains plug and socket which may be looked, so that an infant cannot pull the plug out of the socket.

1.2 Mains sockets present a serious danger to the crawling or toddling infant. Sharp objects may be pushed into empty sockets. This problem has been addressed in the past by the introduction of blank plugs to occupy the holes. However, these blanks may be removed by the infant, once again exposing the holes. Worse still, real plugs in occupied sockets may be partially removed, exposing live pins.

1.3 A solution is proposed where the socket is kept safe by locking the plug in position so that the infant cannot remove it.

2 Description 2.1 Referring to figure 1/3, a mains socket, 1, is provided with a threaded hole, 2, which may be directly moulded into the socket, or machined directly into the socket material, or produced by means of a threaded insert.

2.2 The threaded hole may be located so as not to impinge on any electrical components within the socket assembly.

2.3 A corresponding through-hole, 4, is provided on the mains plug, 3. This hole may be located so as not to impinge on any electrical components in the plug assembly.

2.4 Hole,4, is counter-bored so as to provide a recess to accommodate the head of bolt, 5.

2.5 With plug, 3, inserted into socket, 1, screw, 5, may be inserted into hole, 4, and tightened so as to screw into threaded hole, 2, fastening the plug and socket together.

2.6 The bolt may take the form of a socket cap-head bolt, requiring the use of an allen-key for tightening or untightening. This would make removal of the plug by an infant practically impossible.

2.7 Alternatively, a special screw or bolt requiring a key of some other profile may be used, making removal of the plug difficult for any unauthorised person.

2.8 Alternatively, a simple flat, Phillips, or posidrive screw or bolt may be used, requiring the use of a screw-driver for insertion or removal.

2.9 In an alternative embodiment ofthe invention, figure 2/3, the plug, 1, is provided with a through hole with a recess, 2. seated in this hole is a bolt or screw which may have a hexagonal head, 6. A finger-knob,3, has a socket, 4 which may be hexagonal to fit over the head of the bolt, 6. The knob is retained in the recess by means of a shoulder, 7, an an overhang, 8. Which interfere sufficiently to provide a snap-fit assembly for knob and recess.

The knob captures spring, S, in the hole, and the knob must be pushed in against this spring to engage with the head of the screw. Thus, a complicated action involving pushing and twisting is required to remove the plug from the socket.

3.0 In an alternative embodiment of the invention, referring to figure 3/3, a socket, 1, is provided with a non-circular key-hole, 2. Plug, 3, is provided with a dial, 4, which is connected to a shaft, 7, which has an offset feature, 8, corresponding to keyhole, 2. The dial, 4, may be marked with an arrow, 5, and the dial may be turned by hand so that the arrow lines up with a corresponding arrow, 6, on the back of the plug. Alternatively, other markings such as dots may be used for either or both arrows.

3.1 With the arrows or markings aligned, the shaft, 7, and offset, 8, are aligned with the shape of the keyhole, 2, allowing the shaft to penetrate the keyhole, and the plug to be inserted into socket, 1. At this point, the dial may be turned so that the arrows or markings do not align, whereupon the plug cannot be removed from the socket. In order to remove the plug from the socket, the dial, 4, must be turned until the markings on the dial are in alignment with the markings on the base, before pulling out the plug.

Claims

1. A mains plug and socket with provision for securing the plug to the socket in order to prevent unwanted disconnection.

2. As in 1, whereby the socket is provided with a threaded hole, and the plug is provided with a coincident through-hole, to allow securing by means of of a screw or bolt.

3. As in 2, whereby the screw or bolt may be a socket-head screw or special security screw which may only be undone by means of a special key.

4. As in 1, whereby the plug is locked to the socket by means of a cylinder-lock or other key-operated lock.

5. As in 1, whereby the socket is provided with a key-hole, and the plug is provided with a lugged shaft which may be turned by means of a knob on the plug, allowing disconnection only when the shaft is in a certain orientation.