AU2008212065A1

AU2008212065A1 - A lockable three-pin switch socket

Info

Publication number: AU2008212065A1
Application number: AU2008212065A
Authority: AU
Inventors: Hew Ah Kow
Original assignee: Fong Lee Yip
Current assignee: Fong Lee Yip
Priority date: 2007-09-24
Filing date: 2008-09-09
Publication date: 2009-04-09
Also published as: AU2008101273A4

Description

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P/00/011 Regulation 3.2

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ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "A LOCKABLE THREE-PIN SWITCH SOCKET" The following statement is a full description of this invention, including the best method of performing it known to me/us: 00 C A LOCKABLE THREE-PIN SWITCH SOCKET TECHNICAL FIELD The present invention relates generally to a three-pin switch socket. It relates specifically to a lockable three-pin switch socket where a spring-loaded locking and blanking mechanism is applied to lock the on-off switch and to blank the pin openings when the socket is not plugged.

00 BACKGROUND ART A traditional three-pin switch socket has an on-off switch and three pin openings to receive a plug. When the plug is removed, the pin openings are exposed. The on-off switch is always free to be switched on and off. If any metallic element is accidentally inserted to the live pin opening, electrical current will be transmitted, causing an electrocution. There has been several reporting of such accidents.

Several prior art safety measures are employed to rectify the above problem. One method is to employ a blank plug to close off the pin openings of the three-pin switch socket. Another method is to employ an internal spring-loaded blanking mechanism, which will blank off the pin openings, whenever a plug is removed. However, the on-off switch is always free to be switched on and off.

SUMMARY OF THE INVENTION The present invention has therefore as a primary object to blank off three pin openings of a three-pin switch socket while locking its on-off switch when the three-pin switch socket is not plugged.

This primary object is achieved in that a substantially U-shaped bracket is integrally provided at the back of the three-pin switch socket below the on-off switch and the three pin openings. A locking and blanking mechanism is disposed in between the on-off switch, the three pin openings and the substantially U-shaped bracket. The locking and blanking mechanism further comprises an integral assembly of an inverted T-shaped arm attached to a second vertical arm disposed at its side, the inverted T-shaped arm having a first vertical arm and two side arms. The two side arms blank the two bottom pin openings of the three-pin switch socket and the first vertical arm blanks the top pin \2 00 opening; and the bases of the first and the second vertical arms include each a housing to receive a spring. The tip of the second vertical arm engages the on-off switch and locks it.

Another object of the present invention is to provide a lockable three-pin switch socket to t 5 two or more three-pin switch sockets in a gang.

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These and other objects will become evident, following the disclosure below.

00 BRIEF DESCRIPTION OF THE DRAWINGS SIn order that the present invention may be more readily understood, the following description is given, by way of example, of one specific embodiment in accordance to the present invention. Reference is made to the accompanying drawings, in which: Figure l a is a perspective view of a locking and blanking mechanism, with to-be-loaded springs, made in accordance to the present invention.

Figure lb is a reversed view of the spring-loaded locking and blanking mechanism as shown in Figure Ia.

Figure 2a is a back view of a three-pin switch socket installed with the spring-loaded locking and blanking mechanism made in accordance to the present invention, when a three-pin plug has been inserted.

Figure 2b is a partial side cross-section view of the locking and blanking mechanism taken along an on-off switch as shown in Figure 2a, whence the on-off switch is disengaged from the locking and blanking mechanism.

Figure 2c is a perspective front view of the three-pin switch socket, showing the threepin plug being partially inserted and the position of the locking and blanking mechanism in dotted lines, without showing the springs and a substantially U-shaped bracket.

Figure 3a is a back view of the three-pin switch socket installed with the spring-loaded locking and blanking mechanism made in accordance to the present invention, when the three-pin plug has been removed.

00 O Figure 3b is a partial side cross-section view of the locking and blanking mechanism taken along the on-off switch as shown in Figure 3a, whence the on-off switch is engaged and locked by the locking and blanking mechanism.

Figure 4a shows a perspective view of a gang of two three-pin switch sockets made in accordance to the present invention, with a three-pin plug being inserted into the right-

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hand three-pin switch socket, and the positions of the two locking and blanking mechanisms in dotted lines.

00 0Figure 4b shows a back view of a gang of two three-pin switch sockets made in C accordance to the present invention, with a three-pin plug being inserted into the lefthand three-pin switch socket, and the positions of the two locking and blanking mechanisms.

DETAILED DESCRIPTION A traditional three-pin switch socket carries an on-off switch and three pin openings (12, 13). With the assistance of an electrical circuitry, the on-off switch (11) can be connected electrically when a three-pin plug (40) is inserted. The three pin openings (13, 12) assume the positions of one top pin opening (13) and two bottom pin openings (12).

In order to effect a locking action on the on-off switch (11) of a three-pin switch socket a locking and blanking mechanism (20) is appropriately disposed behind and inside the three-pin switch socket A substantially U-shaped bracket (30) is integrally provided at the back of the three-pin switch socket so that the locking and blanking mechanism (20) is disposed thereon.

As seen in Figures l a and I b, the locking and blanking mechanism (20) comprises an integral assembly of an inverted T-shaped arm attached to a second vertical arm (22) disposed at its side. The inverted T-shaped arm has a first vertical arm (21) and two side arms The two side arms (23) blank the two bottom pin openings (12) and the first vertical arm (21) blanks the top pin opening The bases of the first and the second vertical arms (21, 22) include each a housing (25) to receive a spring The two springs (24) are disposed in between the housings (25) of the first and the second vertical arms (21, 22) and the substantially U-shaped bracket These provide 00 the spring-loaded action to the locking and blanking mechanism At least a vertical guide (31) is provided to allow the locking and blanking mechanism (20) to move up and down.

As seen in Figures 2a, 2b and 2c, a three-pin plug (40) has been inserted to the three-pin switch socket The first vertical arm (21) and the two side arms (23) are urged to Smove downward, while moving the tip of the second vertical arm (22) away from the on- Soff switch The on-off switch (11) is thus disengaged.

00 SAs seen in Figures 3a and 3b, the three-pin plug (40) has been removed from the threepin switch socket The springs (24) in the housings (25) of the first and the second vertical arms (21, 22) would urge the locking and blanking mechanism (20) to move upwardly. The tip of the second vertical arm (22) engages the on-off switch (11) and locks it; while the first vertical arm (21) and the two side arms (23) blank off the three pin openings (13, 12).

It must be understood that the teaching of the present invention can be easily applied to a gang of multiple three-pin switch sockets. The exact design of the locking and blanking mechanism (20) is determined by the location of the on-off switch (11) in relation with that of the three pin openings (12, 13) of a three-pin switch socket In Figures 4a and 4b, a gang of two three-pin switch sockets is shown. The two on-off switches (11) are disposed side by side in the middle of the gang of a left-hand three-pin switch socket and a right-hand three-pin switch socket. The location of each on-off switch (11) can vary on the three-pin switch socket or gang of three-pin switch sockets.

From the above disclosure, it is clear that the present invention teaches a method of locking an on-off switch (11) and blanking the three pin openings (12, 13) with a springloaded locking and blanking mechanism which is operable by the insertion and removal of a three-pin plug The method includes the steps of providing a substantially U-shaped bracket (30) at the back of a three-pin switch socket (10) below the on-off switch (11) and the three pin openings (12, 13); providing an integral springloaded locking and blanking mechanism (20) of two first and second vertical arms (21, 22) and two side arms whence the locking and blanking mechanism (20) is allowed 00 to move up and down; disposing the spring-loaded locking and blanking mechanism in between the substantially U-shaped bracket (30) and the on-off switch (11) and the three pin openings (12, 13); locking the on-off switch (11) with the tip of the second vertical arm and blanking the three pin openings (13, 12) with the first vertical arm (21) and the two side arms whereby the spring-loaded locking and blanking O mechanism (20) is operable by the insertion and removal of a three-pin plug (40) into and Sfrom the three pin openings (12, 13).

00 0It is clear that the method of the present invention is also applicable to a gang of multiple Sthree-pin switch sockets. The method includes the steps of providing a substantially Ushaped bracket (30) at the back of each three-pin switch socket (10) below the on-off switch (11) and three pin openings (12, 13); providing an integral spring-loaded locking and blanking mechanism (20) of two first and second vertical arms (21, 22) and two side arms whence the locking and blanking mechanism (20) is allowed to move up and down; disposing the spring-loaded locking and blanking mechanism (20) in between each substantially U-shaped bracket (30) and the on-off switch (11) and the three pin openings (12, 13) of each three-pin switch socket locking the on-off switch (11) with the tip of the second vertical arm and blanking the three openings (13, 12) with the first vertical arm (21) and the two side arms whereby the spring-loaded locking and blanking mechanism (20) is operable by the insertion and removal of a three-pin plug (40) into and from the three pin openings (12, 13) of each three-pin switch socket To those skilled in the art, the present invention in the form of a lockable three-pin switch socket (10) can be wall-mounted, or applied to a trailing extension cord of multiple three-pin switch sockets.