AU714458B2 - An electrical power outlet device and switch contacts therefor - Google Patents

Description

-1I- P/00/0011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

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004 4 Name of Applicant: Actual Inventors Address for service in Australia: Invention Title: SCHITECH PTY LTD Rado Starec James Gerard Cowhey Antonino Schiavello CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia AN ELECTRICAL POWER OUTLET DEVICE AND SWITCH CONTACTS THEREFOR The following statement is a fll description of this invention, including the best method of perfor-ming it known to us -2- AN ELECTRICAL POWER OUTLET DEVICE AND SWITCH CONTACTS

THEREFOR

This invention relates to electrical power outlet devices and, in particular, to a device adapted to be connected to a source of electricity and having one or more outlet sockets for receiving one or more electrical plugs connected to electrical appliances.

It also relates to switch contacts for such a power outlet device.

It is known to provide a multi-socket device having a plurality of power outlet sockets to enable a plurality of electrical appliances to be connected to a source of power at a single location.

Multi-socket power outlet devices generally consist of a housing formed of at least two body parts, one of which (usually the upper part) has two or more sockets see. consisting of three apertures for receiving the active, neutral and earth pins of an electrical plug. Each socket has associated internal conductive components within the housing, and electrical conductors are required to provide an electrical connection from the internal conductive components of each socket to the source of electrical power outside the housing. Usually, the internal conductive components are directly contacted by the pins of a plug inserted into the socket. However, this is not always satisfactory or desirable.

000. According to one aspect of the invention, there is provided an electrical .00. 20 power outlet device comprising a socket housing formed of a plurality of housing parts, said housing having at least one set of socket apertures in a surface thereof forming an electrical socket for receiving the pins of an electrical plug, electrical terminals provided at at least one side or end of the housing for connection to a mains power supply, and a plurality of electrical conductors providing a connection between said terminals and said electrical socket, wherein at least one of said socket apertures has associated therewith a spring-loaded electrical switch contact provided within the housing.

Preferably, the power outlet device has more than one set of socket apertures so that it provides a plurality of sockets capable of receiving a corresponding number of electrical plugs. Each socket preferably has three apertures for receiving the active, JRG:1A26286D[V 25 June 1999 -3neutral and earth pins of an electrical plug, and in this case the housing will include active, neutral and earth conductors to provide an electrical connection from each socket within the housing to terminals at at least one side or end of the housing for connection to a three phase mains power supply.

In a preferred form of the invention, the power outlet device is of elongate form having terminals at opposite ends of the housing for connection to the mains power supply. Preferably, the terminals at one end of the housing are in the form of pin connectors and the terminals at the other end of the housing are in the form of socket connectors. In this form of the invention, the power outlet device can form part of a modular wiring system which includes a plurality or network of power outlet •'-devices interconnected by extension leads, each extension lead having a plug of pin connectors at one end and a socket of pin-receiving connectors at its other end for cooperation with pin-receiving terminals and pin-terminals respectively such as those of a power outlet device in accordance with the invention.

Preferably, spring loaded electrical contacts are associated with the active and neutral apertures of a socket and form part of switches activated by the insertion of the active and neutral pins of an electrical plug into the active and neutral apertures of the socket.

Each spring-loaded electrical contact associated with an aperture of a socket is 20 preferably received within a contact chamber which may conveniently be formed by internal wall portions provided on one or more of the housing parts. The internal wall portions may also assist in supporting portions of the electrical conductors at required levels within the housing. In one preferred embodiment, the or each spring-loaded electrical contact comprises a contact member having first and second limbs joined by an intermediate bridging portion forming a lower, wider portion remote from the associated socket aperture, and a narrower, upper portion for receiving the pin of a plug inserted into the socket, whereby insertion of a pin into a socket aperture causes at least one of the limfbs to move to place the pin in electrical connection with an associated electrical conductor within the housing.

According to another aspect of the invention there is provided a spring-loaded JRG:IA26286DIV 25 June 1999 electrical contact for an electrical power outlet device having at least one socket, wherein the electrical contact has a first limb connected to a second limb by a bridging portion so as to form a wider part adjacent the bridging portion and a narrower part between the limbs for receiving a pin of an electrical plug inserted into a socket aperture with which the electrical contact is associated, at least one of the limbs being movable upon insertion of a pin between the limbs to place the pin into electrical connection with an associated electrical conductor.

Preferably, the first limb of the contact member is adapted to be fixedly retained in the power outlet device and the second limb is movable relative to the first limb upon insertion of a pin between the limbs. The movable limb may carry a switch contact element on its end remote from the bridging portion which is preferably :°moo o movable into contact with a corresponding switch contact element on an associated one of the electrical conductors or on a fixed contact member connected to the associated electrical conductor.

The spring-loaded electrical switch contacts may be substantially bulb-shaped.

It has, however, been found that one disadvantage with an almost symmetrical bulbshape of the spring loaded electrical contacts is a slight risk of arcing between the switch contact element on the movable limb of the contact element and the switch contact portion of the electrical conductor when the distance between the switch 20 contacts is insufficient to prevent arcing. Such a power outlet device therefore requires S* accurate manufacturing tolerances and careful assembly.

In order to reduce the likelihood of arcing, it is now proposed to provide an electrical contact member in which the first and second limbs have side portions extending alongside each other in generally the same direction at an angle inclined to the direction of insertion of the pin into the socket.

Preferably, the side portions are substantially parallel and extend at approximately the same inclined angle to the central axis of an aperture of the socket into which the pin of the electrical plug can be inserted. Such an arrangement results in greater lateral displacement of the second limb carrying the movable switch contact when the pin is inserted, enabling a fixed switch contact which is engageable by the JRG:JA26286DIV 25 June 1999 movable switch contact to be located a greater distance away from the movable switch contact when the pin is removed from the socket, resulting in a reduced likelihood of arcing.

The side portions of the first and second limbs preferably extend at an angle to the direction of insertion of the pin falling substantially within the range from about to about 200, and more preferably an angle of approximately 12.

Various embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is an external view from above of a multi-socket power outlet device in accordance with the invention formed from upper and lower housing parts; .i Figure 2 is an internal view from below of the device of Figure 1 with the lower housing part removed; Figure 3 is an internal view from below of an upper housing part of the device of Figure 1; Figure 4 is an internal view from above of a lower housing part of the device of Figure 1; Figure 5 is an underneath plan view of an earth conductor of the device of Figure 1; Figure 6 is an inverted side elevation of the earth conductor of Figure 20 Figure 7 is an isometric view of the earth conductor of Figure :'..Figure 8 is an underneath plan view of a neutral conductor of the device of Figure 1; Figure 9 is an inverted side view of the neutral conductor of Figure 8; Figure 10 is an isometric view of the neutral conductor of Figure 8; Figure 11 is an underneath plan view of an active conductor of the device of Figure 1; Figure 12 is an inverted side view of the active conductor of Figure 11; Figure 13 is an isometric view of the active conductor of Figure 11; Figure 14 is a sectional view on the line I-I through an active or neutral pin receiving aperture of a socket of the device; JRGJA26286DIV 25 J1999 Figure 15 is a sectional view similar to Figure 14 with an active or neutral pin of an electrical plug fully inserted into the socket aperture; Figure 16 is a sectional view on the line IM-1 of Figure 2 of an earth-receiving aperture of a socket of the device; Figure 17 is a view similar to Figure 16 with an earth pin of a plug fully inserted into the aperture of the socket; Figure 18 is a sectional view on the line 111-III of Figure 1 through an end part of the device; Figure 19 is an external view from above of a modified multi-socket power outlet device formed from upper and lower housing parts; Figure 20 is a view from above of a lower housing part of the multi-socket power outlet device of Figure 19; *.**Figure 21 is an internal view from below of the upper housing part of the multi-socket power outlet device of Figure 19; Figure 22 is an internal view from below of the assembled device of Figure 19 with the lower housing part removed; Figure 23 is a section on the line IV-IV of Figure 19; Figure 24 is an underneath plan view of the active conductor of the device; Figure 25 is an underneath plan view of the earth conductor of the device; 20 Figure 26 is an underneath view of the neutral conductor of the device; *EFigure 27 is a sectional view through an active pin-receiving aperture of a socket of the power outlet taken on the line A-A of Figure 19; Figure 28 is an enlarged view of part of Figure 27; Figure 29 is a view similar to Figure 28 with a pin of an electrical plug inserted; Figure 30 is a sectional view through an earth pin-receiving aperture of a socket of the power outlet device taken on the line B-B of Figure 19; Figure 31 is a view through the earth pin receiving aperture taken on the line of Figure 19; Figure 32 is an enlarged side view of the spring-loaded electrical contact JRG:JA26286DIV 2 ue19 25 June 1999 -7shown in Figures 27 to 29; Figure 33 is an end view of the spring-loaded electrical contact; Figure 34 is a section on the line C-C of Figure 33; Figure 35 is a front view of the fixed contact shown in Figure 27; Figure 36 is a side view of the fixed contact of Figure Figure 37 is a section on the line D-D of Figure Figure 38 is an external view from above of another modified multi-socket power outlet device; Figure 39 is a view from above of the lower housing part of the multi-socket power outlet device of Figure 38; S.i Figure 40 is a view from below of the upper housing part of the multi-socket power outlet device of Figure 38; :Figure 41 is an internal view from below of the assembled device with the lower housing part removed; Figure 42 is an underneath plan view of the active conductor of the device of Figure 38; Figure 43 is an underneath plan view of the earth conductor of the device of Figure 38; Figure 44 is an underneath plan view of the neutral conductor of the device of S 20 Figure 38; Figure 45 is a part section on the line E-E of Figure 41; Figure 46 is a part section on the line F-F of Figure 41; and Figure 47 is a part section on the line G-G of Figure 41.

The multi-socket power outlet device shown in Figures 1 to 18 of the drawings comprises an elongate housing 1 formed of an upper housing part 2 and a lower housing part 3 and having first and second electrical sockets 4 and 5, each of which is adapted to receive a three pin electrical plug having active, neutral and earth pins.

The upper housing part 2 has a top wall 20, side walls 22 and end portions 23 and 25, whereas the lower housing part 3 consists of a base plate of similar shape having side flanges 32 and end portions 33 and 35, the side flanges 32 being adapted JRG:IA26286DV 25 June 1999

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-8to be secured to the lower edges of the side walls 22 of the upper housing part 2.

Each socket 4 and 5 has a set of three apertures 12, 14 and 16 formed in the top wall 20 of the upper housing part 2, each aperture 12, 14 and 16 being adapted to receive the active, neutral and earth pins respectively of an electrical plug.

The end portion 23 at one end of the upper housing part 2 (the left hand end as shown in Figures 2 and 3) has a transversely extending wall 24 formed with three recesses 27, 28 and 29 which receive conductive active, neutral and earth terminals 42, 44 and 46 respectively in the form of pins which extend from within the housing to outside the housing. Similar recesses 17, 18 and 19 are provided in a transversely extending wall 34 of the end portion 33 of the lower housing part 3. The pin terminals .i 42, 44 and 46 form a three-pin plug connection 40 which enables the power outlet oooo device to be connected to other power outlet devices and/or to a three-phase mains power supply by an extension lead having a socket complementary to the three-pin plug connection 40. The end portion 25 at the opposite end of the upper housing part 2 (the right hand end as shown in Figures 1 and 2) has a transversely extending wall 26 formed with three recesses 47, 48 and 49, each of which leads to a respective pinreceiving terminal 52, 54 and 56 located within the housing. Similar recesses 37, 38 and 39 are provided in a transversely extending wall 36 of the lower housing part 3.

o 9bi The pin-receiving terminals 52, 54 and 56 and the pairs of recesses 37, 47; 38, 48; and i: 20 39, 49 form a socket connection 50 which enables the power outlet device to be S'connected to another power outlet device and/or to a three-phase mains power supply by an extension lead having a three-pin connector of similar form to the plug connection As shown in Figures 5 to 13, each pin-receiving terminal 52, 54 and 56 is formed by a bifurcated conductive member having a terminal head portion 57 and two fork portions 58. The fork portions 58 extend from the terminal head portion 57 with a gap therebetween before tapering inwardly to meet each other at a position towards respective pairs of the recesses 37, 47; 38, 48; 39, 49, with the ends 59 of the fork portions extending away from each other to form a mouth for receiving a pin terminal of a complementary plug connector on an extension lead. When the pins of a plug on JRG:JA26286DIV 25 June 1999 -9an extension lead or the like are inserted into the mouths of the bifurcated pinreceiving terminals 52, 54 and 56 they force the fork portions 58 of the terminals apart and the resilience of the fork portions thus assists in retaining the plug connector of the extension lead positively within the socket connection formed by the three pinreceiving terminals 52, 54 and 56. The central pin-receiving member 56 is an earth connector which is disposed within two longitudinally extending walls or partitions formed on the lower surface of the top wall of the upper housing part 2. The walls or partitions 60 isolate the earth pin-receiving terminal 56 from the outer terminals 52 and 54 which are active and neutral pin-receiving terminals 52 and 54. Two shorter longitudinal partitions 62 extend partly along the sides of the active and neutral pinreceiving terminals 52 and 56 and are formed with tubular locating portions 61 which, •together with complementary post formations 63 on the lower housing part 3 assist in locating the upper and lower housing parts 2 and 3 together during assembly. A plurality of transversely extending wall portions 64 extend partly between the longitudinal partitions 60 and 62 to assist in locating and retaining the pin-receiving terminals 52, 54 and 56 within chambers formed by the longitudinal wall portions and 62.

The pin terminals 42, 44 and 46 are also electrically isolated from one another and located in position by longitudinally extending walls or partitions 65, 66, 67 and 68 formed on the upper housing part 2. Also, a transversely extending partition 69 is 0 formed on the upper housing part 2 with tubular formations 70 being provided to cooperate with complementary post formations 71 on the lower housing part 14 to assist in location of the housing parts 2 and 3 together during assembly.

Referring more particularly to Figures 2 to 4 and 14 to 17 of the drawings, below each pin-receiving aperture 12, 14 and 16 there is provided a respective contact chamber 72, 74 and 76, each of which has side and end walls formed by internal wall portions of the upper and lower housing parts 2 and 3. Figures 14 and 15 of the drawings show a contact chamber 72, 74 below one of the active or neutral pinreceiving apertures 12, 14 which has end walls formed by wall portions 80 and 82 which depend downwardly from the top wall 20 of the upper housing part 2 and by JRG:JA26286DIV 25 June 1999 wall portions 84 and 86 which extend upwardly from the base plate 30 of the lower housing part 3. The contact chamber contains a spring loaded electrical contact switch member 88 which is adapted to receive the active or neutral pin 89 of an electrical plug 90 inserted into the socket aperture 34.

The contact switch member 88 is formed of a generally bulb-shaped conductive wire element having a rounded lower portion 92, and limb portions 93 and 94 which extend upwardly and inwardly from the lower portion 92 to meet at an intermediate position before extending outwardly to the upper ends 96 and 98 of the limb portions. The upper end 96 of one of the limbs 93 is retained between the wall portion 80 and a finger 97 extending downwardly from the top wall 20 of the upper housing part 2, and the upper end portion 98 of the other limb portion 94 has a silver .eo.

switch contact 99 thereon which is movable into contact with a silver contact 199 on a switch portion 127, 147 of an active or neutral electrical conductor 120, 140 which provides the electrical connection between the active or neutral terminals 42, 44 and 52, 54 at opposite ends of the housing.

The neutral contact chambers 74 and the active contact chambers 72 of the first and second sockets 16 and 18 are of substantially identical form as shown in Figures 14 and 15, and include electrical contact switch members of similar form to the 999• 00 contact switch member 88 shown in Figures 14 and 20 Figures 16 and 17 show an earth contact chamber 76 below an earth pinreceiving aperture 36 and a spring-loaded electrical contact element 108 received in the chamber 76 and which is adapted to receive an earth pin 101 of an electrical plug inserted into the socket aperture 36. The contact chamber 76 has side and end walls formed by wall portions which depend downwardly from the upper housing part and wall portions which extend upwardly from the base of the lower housing part.

Figures 17 and 18 show end wall portions 100 and 102 which depend downwardly from the top wall 20 of the upper housing part and wall portions 104 and 106 which extend upwardly from the base plate 30 of the lower housing part 14 and which meet with the lower ends of the wall portions 100 and 102. The electrical contact element 108 is similar to the switch contact member 88 in that it is also formed of a generally JRG:JA26286DIV 25 June 1999 -11bulb-shaped conductive wire element having a rounded lower portion 112, limb portions 113 and 114 which extend upwardly and inwardly from the lower bulbportion 112 and outwardly extending end portions 116 and 118 which form a mouth for receiving the earth pin 101 of electrical plug 90. The contact element 108 differs from the neutral switch contact member 88 in that a vertically extending contact portion 167, 169 of an earth conductor 160 extends into the mouth of the contact member 108 between the limb portions 113 and 114.

The active, neutral and earth conductors 120, 140 and 160 comprise overlapping bare electrical conductors which provide electrical connections between the pin terminals 42, 44 and 46 and the pin-receiving terminals 52, 54 and 56 at .i opposite ends of the housing and the electrical contact members 88 and 108 located within the contact chambers 72, 74 and 76 below the pin-receiving apertures 12, 14 and 16 of the first and second sockets 4 and Each of the active, neutral and earth conductors 120, 140 and 160 comprises a 15 solid metal electrical conductor preferably formed from brass wire two millimetres in o. diameter. Each conductor is formed with a plurality of bends so that when assembled in the housing it has generally horizontally extending portions at different heights or a levels within the housing joined by generally vertically extending portions. As seen from left to right in Figures 2 and 11 to 13, the active conductor 120 has a first 20 horizontal portion 121 at a first level connected at one end to the pin terminal 42, a second horizontal portion 122 at a second level which is joined by a first vertically extending portion 221 to the other end of the first portion 121 and which leads into the active contact chamber 72 of the first socket 4, a vertically extending generally Ushaped switch portion 127 within the contact chamber 72 which forms a contact member with which the switch contact member 88 within the chamber is engageable, a third horizontal portion also on the second level joined to the portion 127 and which leads out of the contact chamber 72, a cross-over part 128 comprising a diagonally extending horizontal portion 220 at the first level having vertical portions 222, 223 at each end, one of which 223 is joined to the third horizontal portion 123, a horizontal portion 124 on the second level which is joined to the other vertical portion 224 of the JRG:JA26286DV 25J1we 1999

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-12cross-over part 128 and which leads into the active contact chamber 72 of the second socket 5, a further U-shaped vertically extending switch portion 129 joined to the fourth horizontally extending portion 124 within the second active contact chamber 72, a fifth horizontal portion 125 on the second level leading from the second active contact chamber 72, and an L-shaped sixth horizontal portion 126 on the first level formed by a first limb 226 joined to the fifth horizontal portion 125 by a vertically extending portion 225 with its second limb 227 connected to the active pin-receiving terminal 52. As shown in Figures 2 and 11 to 13, the first horizontally portion 121 has an intermediate diagonally extending part 228 between longitudinally extending parts 229 and 230.

The neutral conductor 140 is of generally similar form to the active conductor 120 and as shown from left to right in Figures 2 and 8 to 10 has an L-shaped first horizontal portion 141 on the first level within the housing having a first longitudinally extending limb 243 connected to the neutral pin terminal 44 and a second limb 244 which extends transversely towards the adjacent side of the housing, second horizontal portion 142 on the second level having a longitudinally extending part 245 joined by a first vertically extending portion 241 to the end of the transversely extending second limb 244 of the first portion 141 and a diagonally G "•extending part 246 which leads in to the neutral contact chamber 74 of the first socket 20 16, a U-shaped vertically extending switch portion 147 which is joined to an end of S. the diagonally extending part 246 of the second portion 142 within the contact chamber 74 and which forms a switch with the associated electrical contact member 88 within that chamber, a third horizontal portion 143 on the second level which leads from the switch portion 147 out of the contact chamber 74, a cross-over portion 148 on the second level joined to the third portion 143 and which extends diagonally and transversely across the housing, a fourth horizontal portion 144 also on the second level joined to the diagonally extending cross-over portion 148 and which leads into the neutral contact chamber 74 of the second switch 18, a second U-shaped vertically extending switch portion 149 which, together with an associated electrical contact switch member 88, forms a switch in the second neutral contact chamber 74, a fifth IRG:1A26286DIV 25 June 1999 13 horizontal portion 145 on the second level leading from the neutral contact chamber 74 of the second socket, and a longitudinally extending sixth horizontal portion 146 on the first level joined at one end to the fifth horizontal portion 145 by a second vertically extending portion 242 connected at its other end to the neutral pin-receiving terminal 54. The fifth horizontal portion 145 has a first part 247 connected to the switch portion 149 and which leads out of the contact chamber 74 a transversely extending second part 248 joined at one end to the part 247 and a longitudinally extending part 249 joined to the other end of the transversely extending part 248.

The earth conductor 160 as seen from left to right in Figure 2 has a first horizontal portion 161 on a first level having a longitudinally extending end part 261 at one end connected to the earth pin terminal 46, an intermediate V-shaped part 262 which extends around one of the tubular formations 70 and a longitudinally extending ****part 263 at its other end joined to a first vertically extending contact portion 167 which leads into the earth contact chamber 76 of the first socket 4 and which is arranged to extend between the limb portions 113 and 114 of the spring loaded contact member 108, a second horizontal portion 162 on a second level connected to the contact portion 167 and which leads from the earth contact chamber 76 and extends transversely to a side of the housing, a third horizontal portion 163 on the second level off@ joined to the second portion 162 and which extends longitudinally along the side of "see 20 the housing, a fourth horizontal portion 164 on the second level joined to the third :00 portion 163 and which extends transversely inwards leading to the earth contact chamber 76 of the second socket 5, a second vertically extending contact portion 169 which extends between the limb portions 113 and 114 of the associated spring-loaded contact member 108 within the second earth contact chamber 76, and a fifth, longitudinally extending, horizontal portion 165 on the first level connected at one end to the vertical contact portion 169 and which extends out of the earth contact chamber 76 with its other end connected to the earth pin-receiving terminal 56.

It will be appreciated that in the arrangement of the active, neutral and earth conductors 120, 140 and 160 described above and as illustrated by Figure 2, the conductors overlap and cross over each other at several locations within the housing.

JRG:JA26286D1V 2 ue19 25 Jme 1999 -14- Since bare metal conductors are used, it is important that accidental or inadvertent contact between the conductors is avoided during use of the multi-socket power outlet device. For this purpose, a plurality of partitions integrally formed with the upper and lower housing parts 2 and 3 are provided which, together with the wall portions of the contact chambers 72, 74 and 76 support the horizontal portions of the overlapping conductors at the two different levels in the housing. Several of these partitions are shown in Figures 2 and 3 wherein the upper housing part 2 has partitions 171 to 177 which locate and support various portions at the first level which corresponds to the level at which the pin and pin-receiving terminals are located. A transversely S 10 extending partition 171 supports the first longitudinally extending conductor portions 121, 141 and 161 at the first level, diagonally extending partitions 172 and 173 support the diagonally extending cross-over portion 128 of the active conductor so that it is held out of contact with the diagonally extending cross-over portion 148 of the neutral conductor 140, and partitions 174 and 175 are provided to support different 15 parts of the L-shaped sixth horizontal portion 124 of the active conductor at the first level within the housing. Partition 175 extends transversely and also serves to separate the horizontal portions 145 and 164 of the neutral and earth conductors respectively.

The upper housing part 2 also has shorter partitions which assist in retaining 20 the various portions of the conductors at the second level which corresponds to the level and which conductor portions enter and leave the contact chambers 72, 74 and 76. For instance, partition 181 is a longitudinally extending partition which supports the second earth conductor portion 162, and partitions 182 and 183 are short diagonal portions which support the diagonally extending cross-over portion 148 of the neutral conductor.

Preferably, at least some of the supporting partitions 171 to 176, 181 to 183 and the wall portions 80, 82, 100 and 102 of the contact chambers 72, 74 and 76 have recesses therein for receiving various portions of the conductors so that the conductors can be clipped into the partitions and wall portions to be held securely therein.

The lower housing part 3 is also formed with partitions which assist in JRG:JA26286DIV 25 June 1999 supporting and locating the various portions of the conductors at the two levels within the housing. For instance, partitions 184 extending upwardly from the base 30 of the lower housing part 3 may be provided adjacent to the active and neutral contact chambers 72 and 74 to support portions of the conductor 120 or 140 which enter or leave the contact chamber 72 or 74 (as shown in Figures 14 and The multi-socket connector described above with reference to the drawings may be readily assembled in the following manner. First, an earth sub-assembly comprising the earth conductor 160, the earth pin terminal 46, and the earth pinreceiving terminal 56 is placed in position with the various parts of the earth conductor 160 being clipped into recesses in the appropriate partitions of the upper housing part 2. Then a neutral sub-assembly comprising neutral conductor 140, neutral pin terminal 44 and neutral pin-receiving terminal 54 is placed in position followed by an active sub-assembly comprising active conductor 120, active pin terminal 42 and pin-receiving terminal 52 so that the portions of the conductors 140 15 and 120 are supported and securely held in position by the relevant partitions and wall portions of the upper housing part 12. The electrical switch contact members 88 and 108 are then placed into position in the active, neutral and earth contact chambers 72, 74 and 76 and finally the lower housing part 3 is placed in position and secured to the upper housing part preferably by welding so that the partitions and wall portions of the lower housing part also assist in locating and securely retaining the various conductor portions in position. The electrical power outlet device described above is therefore easy to assemble without requiring the time consuming task of connecting flexible conductive wires with insulating sleeves to the pin terminals and the pinreceiving terminals at opposite ends of the housing. Also, the switches in the active and neutral contact chambers 72 and 74 formed by the switch contact members 88 and the switch contact portions 127, 129, 147 and 149 of the active and neutral conductors 120 and 140 help to make the power outlet device safe to use.

Whilst the electrical power outlet device of Figures 1 to 18 described above operates generally satisfactorily, one disadvantage with the almost symmetrical shape of the spring loaded electrical contacts is a slight risk of arcing between the switch IRG:JA26286DV 25 June 1999 -16contact on the movable limb of the contact element and the switch contact portion of the electrical conductor when the distance between the switch contacts is insufficient to prevent arcing. The power outlet device of Figures 1 to 18 therefore requires accurate manufacturing tolerances and careful assembly. The modified multi-socket power outlet device of Figures 19 to 37 is designed to alleviate this disadvantage.

The modified multi-socket power outlet device shown in Figures 19 to 37 also comprises an elongate housing 1 formed of an upper housing part 2 and a lower housing part 3 and corresponding reference numerals are applied to corresponding parts.

10 The upper and lower housing parts 2 and 3 are generally similar to the housing parts of the multi-socket power outlet device of Figures 1 to 18 which have various internal walls and partitions adapted to locate bare metal electrical conductors connecting the respective active, neutral and earth pin terminals 42, 46 and pinreceiving terminals 52, 54 and 56. In the multi-socket device illustrated in Figures 19 15 to 37, the active, neutral and earth conductors 420, 440 and 460 comprise metal wires which are mostly sheathed with an insulating material and so several of the internal locating walls and partitions of the device of Figures 1 to 18 have been omitted from the housing parts of Figures 19 to 37.

The active conductor 420 shown in Figure 24 has a first sheathed end portion 421 connected to the terminal head portion 57 of the pin-receiving terminal 52, a second sheathed end portion 422 connected to the pin terminal 42 and an intermediate sheathed portion 423. The active conductor 420 has a first conductive wire portion 424 exposed between the sheathed end portion 421 and the intermediate sheathed portion 423 and a second conductive wire portion 425 exposed between the intermediate sheathed portion 423 and the second sheathed end portion 422. The neutral conductor 440 shown in Figure 26 is similar to the active conductor 420 and also has first and second sheathed end portions 441, 442, an intermediate sheathed portion 443 and exposed wire portions 444,445. The earth conductor 460 shown in Figure 25 has a first sheathed end 461 connected to the terminal head portion 57 of the earth pin-receiving terminal 56, a second sheathed end portion 462 connected to the JRG:JA26286DIV 25 June 1999 :111'1-1 -17earth pin terminal 46, an intermediate sheathed portion 463, a first exposed wire portion 464 between the first sheathed end 461 and the intermediate sheathed portion 463 and a second exposed wire portion 465 between the intermediate sheathed portion 463 and the second sheathed end 462.

As shown in Figure 21 to 23, the upper housing part 2 has a transversely extending central partition 270 which has projections 271 and a recess 273 for locating the intermediate parts 223, 243 and 263 of the active, neutral and live conductors where they cross over each other.

Referring more particularly to Figures 20 to 23 and 27 to 31 below each pinreceiving aperture 12, 14, 16 there is provided a respective contact chamber 72, 74, 76; each of which has a side and end walls formed by internal wall portions of the upper and lower housing parts 2 and 3. Figures 27 to 29 show a contact chamber 72 below one of the active pin-receiving apertures 12 which has end walls formed by wall portions 80 to 82 which depend downwardly from the top wall 20 of the upper 15 housing part 2 and by wall portions 84 and 86 which extend upwardly from the base plate 30 of the lower housing part 3. The active contact chambers 72 each contain a spring-loaded electrical contact switch member 188 which is adapted to receive the active pin 89 of an electrical plug 90 inserted into the socket aperture 12. The neutral contact chambers 74 are of substantially identical form to the contact chamber 72 as 20 shown in Figures 27 to 29 and need not be described further herein.

S

Figures 30 and 31 show an earth contact chamber 76 below an earth pinreceiving aperture 16 and an earth contact element 208 received in the chamber 76 and which is adapted to receive an earth pin of an electrical plug inserted into the socket aperture 16. The contact chamber 76 has side and end walls formed by wall portions which depend downwardly from the top wall 20 of the upper housing part and formations which extend upwardly from the base 30 of the lower housing part.

Figures 30 and 31 show side wall portions 200 and end wall portions 202 which depend downwardly from the top wall 20 of the upper housing part and location post 204 which extends upwardly from the base plate 30 of the lower housing part 3.

The earth contact element 208 has a lower portion 212 electrically connected to JRG:JA26286DIV 25 June 1999 -18the bare wire portion 464 of the earth conductor 460 and limb portions 213 and 214 which extend upwardly from the lower portion 212 to form a mouth for receiving the earth pin of an electrical plug. The shape of the contact element 208 of Figures and 31 has been found to provide a more positive retention and better electrical contact with an earth pin than the bulb-shaped contact element of Figures 1 to 19. As shown in Figures 22, 23 and 30, 31 the exposed wire portions 464 and 465 of the earth conductor 460 extend through the earth contact chambers 176 and are in electrical contact with the contact element 208 so that when the earth pin of a plug is inserted into the aperture 16 to extend between and engage the limb portions 213, 214 it is placed in electrical connection with the earth conductor 460 and the earth pin and pinreceiving terminals 46 and 56 at opposite ends of the multi-socket device.

As shown in Figure 22, the second exposed conductive wire portions 424, 425, 444, 445 of the active and neutral conductors 420, 440 extend through the active and neutral contact chambers 72, 74.

15 Each exposed wire portion 424, 425, 444, 445 is crimped to C-shaped electrical contact element 251 at one end of an elongate conductive switch member 250 received between the end wall 82 of the respective contact chamber 172, 174 and a locating member 189 extending downwardly from the top wall 20 of the upper housing member 2. A switch contact 252 is in the form of a silver rivet provided on 20 the other end of the switch member 250. The switch member 250 is shown prior to crimping in more detail in Figures 35 to 37.

Referring more particularly to Figures 32 to 34, the spring-loaded electrical contact switch member 188 comprises a conductive wire strip having first and second limbs 191 and 192 and a substantially semi-circular lower portion 193 which joins the first and second limbs 191 and 192 at their lower ends. A central line L through the semi-circular lower portion 193 extends substantially vertically and preferably coincides with the central vertical axis of the aperture 15 through which the pin 89 of electrical plug 90 can be inserted. The first limb 191 has a substantially straight section 194 extending upwardly and inwardly from one end of the semi-circular lower portion 193 towards the central line L, an outwardly curved middle section 195 and a JRG:JA26286DIV 25 June 1999 -19straight upper end section 196. The second limb 192 has a generally straight section 197 extending upwardly and inwardly from the other end of the semi-circular lower portion 193 to a position where it meets or almost touches the straight section 194 of the first limb 191, a generally straight intermediate section 198 which extends alongside the upper part of the straight section 194, and a generally L-shaped upper section 199 having a transverse part 291 extending outwardly from the upper end of the intermediate section 198 and an upwardly extending end part 292 which is provided with a switch contact 293 in the form of a silver rivet. The generally straight sections 194 and 198 of the first and second limbs 191 and 192 are preferably separated by a gap of approximately 0.lmm and the straight sections preferably extend at an angle of approximately 120 to the central line D.

In the assembled multi-socket outlet, the upper end section 196 of the first limb 191 is fixedly retained between the wall portion 80 and a short partition 180 extending downwardly from the top wall 20 of the upper housing part 2 to define one side of the aperture 14. Another short partition 182 extends downwardly from the top wall 20 to define the other side of the aperture 14 and the transverse part 291 of the second limb 192 rests against the end of this finger 182.

S"The upper end of the second limb 192 is free to move in a generally horizontal direction away from the first limb 191. When a pin 89 of an electrical plug 90 is 20 inserted into the aperture, as shown in Figure 29, the pin 89 forces its way between the straight section 194 of the first limb 91 and the intermediate section 198 of the second limb 192 and the switch contact 293 on the end part 292 of the movable second limb 192 is urged towards and into contact with the switch contact 252 of the fixed switch member 250 which is in electrical connection with a respective active or neutral conductor 220, 240 providing the electrical connection between the active or neutral pin terminals 42, 44 and pin-receiving terminal 52, 54 at the opposite ends of the housing.

The switching operation of each switch member 188 is similar to that of Figures 1 to 18. However, because the generally straight sections 194 and 198 of the first and second limbs 191, 192 of the switch member 188 extend generally parallel to JRG:JA26286DV 25 June 1999 each other and at an acute angle to the central line L, a greater degree of lateral movement of the second limb 192 is achieved when a pin 189 of an electrical plug 190 is inserted into the aperture 14 between the generally straight sections 94 and 98 of the limbs 91, 92 of the switch member 88. This allows the switch contact 252 on the stationary switch member 250 in the position shown in Figure 28 to be located a further distance away from the movable switch contact 293 of the second limb 192 of the movable switch member 188 than the corresponding switch member of Figures 1 to 18 thereby reducing the likelihood of arcing between the switch contacts 252, 293.

Referring to Figures 38 to 47 there is shown a further modified electrical power 10 outlet device similar to that of Figures 19 to 37 and corresponding reference numerals have been applied to corresponding parts. The device ofFigures 38 to 47 differs from of Figures 19 to 37 principally in the orientation of the socket apertures 12, 14, 16 and the shape of the active, neutral and earth conductors 320, 340 and 360.

.t As shown in Figures 38 to 41, the active and neutral socket apertures 12 and 14 15 of each socket 4 and 5 are disposed on opposite sides of a respective transverse axis T on which the earth aperture 16 is disposed. This is in contrast to the device of Figures 19 to 37 in which the earth apertures 16 are disposed on the central longitudinal axis of the housing 1 with the active and neutral socket apertures 12 and 14 disposed on opposite sides of the central longitudinal axis. The power outlet device of Figures 19 S 20 to 37 is intended for use in a horizontal position whereas the power outlet device of Figures 38 to 41 is intended for use in a vertical position.

Referring more particularly to Figures 41 to 44, the shapes of the active, neutral and earth conductors 320, 340, 360 have been modified from those of Figures 24 to 26 so that they extend through differently located contact chambers 272, 274 and 276 below the socket apertures 12, 13 and 14. Otherwise, the active, neutral and earth conductors 420, 440 and 460 are of similar form to the active, neutral and earth conductors 220, 240 and 260 of the embodiment of Figures 19 to 37 having sheathed end and intermediate portions 321, 322, 323; 341, 342, 343; 361, 362, 363 and exposed conductive wire portions 324, 325, 344, 345 and 364, 365. Likewise, the contact chambers 272, 274 and 276 are of similar form to the contact chambers 72, 74 JRG:JA26286DIV 25 June 1999 -21and 76 of the device of Figures 19 to 37 and contain active, neutral and earth contact elements of the same form as described with reference to Figures 27 to 37. The transversely extending central partition 370 of the upper housing part 2 has three separate recesses 371, 372, 373 for locating the intermediate portions of the active, neutral and earth conductors in the housing.

It will be appreciated that various other modifications may be made to the embodiments described without departing from the scope and spirit of the present invention.

**o

C

Claims (25)

1. An electrical power outlet device comprising socket housing formed of a plurality of housing parts, said housing having at least one set of socket apertures in a surface thereof forming an electrical socket for receiving the pins of an electrical plug, electrical terminals provided at at least one side or end of the housing for connection to a mains power supply, and a plurality of electrical conductors providing a connection between said terminals and said electrical socket, wherein at least one of said socket apertures has associated therewith a spring-loaded electrical switch contact provided within the housing.

2. A device according to claim 1 wherein said spring-loaded switch contact is activated by insertion of a pin of an electrical plug into the associated socket aperture.

3. A device according to claim 2 wherein said at least one set of socket apertures 15 includes active and neutral socket apertures, each of which includes a switch contact activated by insertion of an active or neutral pin into an associated active or neutral socket aperture.

4. A device according to any one of the preceding claims wherein the or each 20 socket has three socket apertures for receiving active, neutral and earth terminals of an electrical plug, and three conductors are provided within the housing to provide an electrical connection between active, neutral and earth terminals at a side or at least one end of the housing and the or each socket.

5. A device according to any one of claims 1 to 4 wherein the at least one spring- loaded electrical contact is received within a contact chamber formed by internal wall portions provided on one or more of the housing parts.

6. A device according to any one of the preceding claims wherein the or each spring-loaded electrical contact comprises a contact member having first and second JP.G:JA26286DIV 25June1999 -23- limbs joined by an intermediate bridging portion forming a lower, wider portion remote from the associated socket aperture, and a narrower, upper portion for receiving the pin of a plug inserted into the socket, whereby insertion of a pin into a socket aperture causes at least one of the limbs to move to place the pin in electrical connection with an associated electrical conductor within the housing.

7. A device according to claim 6 wherein the first limb has an end portion fixedly retained in the power outlet device and the second limb is movable upon insertion of a pin into the associated socket aperture. S

8. A device according to claim 6 or claim 7 wherein the movable limb carries a switch contact element which is movable into electrical contact with a corresponding switch contact element provided on or connected to the associated electrical conductor. S9. A device according to claim 8 wherein the corresponding switch contact element is provided on one end of a fixed contact member having its other end S"connected to the associated electrical conductor within the housing.

10. A device according to claim 9 wherein said other end of the fixed contact S. S member is crimped onto the associated electrical conductor.

11. A device according to any one of claims 6 to 10 wherein the spring-loaded electrical contact is substantially bulb-shaped.

12. A device according to any one of claims 6 to 11 wherein the first and second limbs of the spring-loaded electrical contact have side portions extending alongside each other in generally the same direction at an angle inclined to the direction of insertion of a pin into the associated socket. JRG:JA26286DIV 25 June 1999 II i_ I -24-

13. A device according to claim 12 wherein the side portions are substantially parallel and extend at substantially the same inclined angle to the central axis of an associated aperture of the socket.

14. A device according to claim 12 or claim 13 wherein the side portions extend at an angle to the direction of insertion of the pin falling substantially within the range from 5' to 200. A device according to claim 14 wherein the side portions extend at an angle to the direction of insertion of the pin of about 120. :Ve.

16. A device according to any one of claims 12 to 15 wherein the side portions of the first and second limbs almost touch each other prior to insertion of a pin therebetween.

17. A device according to claim 16 wherein the side portions are separated by a distance of about 0. mm prior to insertion of a pin therebetween.

18. A spring loaded electrical contact for an electrical power outlet device having 20 at least one socket, wherein the electrical contact has a first limb connected to a second limb by a bridging portion so as to form a wider part adjacent the bridging portion and a narrower part between the limbs for receiving a pin of an electrical plug inserted into a socket aperture with which the electrical contact is associated, at least one of the limbs being movable upon insertion of a pin between the limbs to place the pin into electrical connection with an associated electrical conductor.

19. A spring-loaded switch contact according to claim 18 wherein the first limb has an end portion adapted to be fixedly retained in a power outlet device and the second limb is movable relative to the first limb upon insertion of a pin between the limbs. JRGJA26286DIV 25June1999 1 A spring-loaded switch contact according to claim 19 wherein the movable limb carries a switch contact element on its end remote from the bridging portion.

21. A device according to any one of claims 18 to 20 wherein the spring-loaded electrical contact is substantially bulb-shaped.

22. A device according to any one of claims 18 to 21 wherein the first and second limbs of the spring-loaded electric contact have side portions extending alongside 10 each other in generally the same direction at an angle inclined to the direction of S. *insertion of a pin into the associated socket.

23. A device according to claim 22 wherein the side portions are substantially parallel and extend at substantially the same inclined angle to the central axis of an 15 associated aperture of the socket. 99 t

24. A device according to claim 22 or claim 23 wherein the side portions extend at ,an angle to the direction of insertion of the pin falling substantially within the range from 50 to 200. .9 A device according to claim 24 wherein the side portions extend at an angle to the direction of insertion of the pin of about 12°.

26. A device according to any one of claims 22 to 25 wherein the side portions of the first and second limbs almost touch each other prior to insertion of a pin therebetween.

27. A device according to claim 26 wherein the side portions are separated by a distance of about 0.1mm prior to insertion of a pin therebetween. JRG:JA26286D[V 25 June 1999 I lr_: -26-

28. An electrical power outlet device according to claim 1 and substantially as described herein with reference to Figures 1 to 18 of the accompanying drawings.

29. An electrical power outlet device substantially as described herein with reference to Figures 19 to 37 of the accompanying drawings. An electrical power outlet device substantially as described herein with reference to Figures 38 to 47 of the accompanying drawings. 10 31. A spring-loaded electrical contact for an electrical power outlet device substantially as described herein with reference to Figures 32 to 34 of the accompanying drawings. 15 DATED: 25 June 1999 CARTER SMITH BEADLE Patent Attorneys for the Applicant: SCHITECH PTY LTD a:00 o JRG:JA26286DIV 25 June 1999