GB2218865A - Plug and socket outlet system - Google Patents

Abstract

A plug for connection to multiple socket outlet or single in-line socket (not shown) or an adaptor (fig. 19) has an abutment 47 for use in disengaging the plug from its socket. The abutment is part of a plug-connection guide. The pins have a shroud 13 which fits between the socket body 31 and a shroud therefor and operates a shutter in a socket. The socket connection has guide parts 33,43. The socket has stepped hard wiring 63, 65, 67 whilst plug pins are a push fit into body mouldings and retained by a lip 28. A socket outlet may have four sockets 101 all to the same level and shutters 51 inserted into side apertures (figs. 2,6), or four sockets at right angles to a plug (fig. 19). <IMAGE>

Description

Title: Plug and Socket and Multiway connector using same.

DESCRIPTION The present invention relates to an electrical accessory, in particular a mains electrical accessory, and more especially to a connector providing one or more socket outlets from an input, and to a plug for use with the sockets, and to the method of construction of the aforesaid.

Mains electrical accessories in the U.K., at least for domestic use, have standardised on the 3-pin flat 13 amp plug and socket for connecting up electrical leads to mains. Such plugs are large and bulky and there are numerous occasions where the socket outlet provisions in a room are insufficient to accommodate all plugs of electrical loads. Domestic Hi Fi typifies the situation, where four or more components have to be provided with mains input.

Providing same, each by way of its own 3-pin plug, requires 4 sockets which are rarely found as standard.

Because of the size of 3-pin 13 amp plug/sockets, adapters providing multiway outlets become large probably unnecessarily so having regard purely to load carrying requirements and hence can become unsightly items. One aspect of the invention aims to provide an adapter which is more acceptable size-wise whilst still being capable of carrying required current loading Most plugs require the body of the plug to be gripped and pulled to remove, this can be difficult where good pin contact is provided and the problem can easily be magnified when plug sizes are reduced, presenting the temptation to pull the wiring itself. A further aim is to provide a plug which is more easily pluged into and removed from its intended socket.

According to a first aspect of the invention then we provide a plug having a body member which presents an accessible abutment when the plug is inserted in a mating socket, which abutment can take a pushing force to facilitate release of the plug from the socket.

According to another aspect of the invention the plug body is provided with an extension for use in guiding the plug into its mating socket or assembly thereof.

More particularly, we find that the abutment of the body member is conveniently on an extension of the plug member, which extension is preferably aligned in parallel with pins of the plug and preferably extends beyond the end of the pin. A particularly convenient construction of plug and socket results where the extended body is greater in length than the depth of the socket when measured from the socket receiving face. This is not essential, and the extension can be of shorter length whilst still permitting it to operate as an abutment to facilitate pushing to disengage the plug.

We find that the extension can also serve advantageously as the guide means for the plug, especially in conjunction with ribbing or shoulders on the socket extending in the direction of plug socket connecting engagement. A further advantageous feature is to have the pins of the plug shrouded, and the socket of the connector receiving the shrouded plug may itself be shrouded - with spacings of course to receive the plug pin shroud. It is further advantageous if the connector also provides an extension forward of the socket face, conveniently as part of the shroud. This socket extension can act as a guide to align the plug with the socket on installation. This may act in addition or as an alternative to the guide provided by the plug extension.

We are concerned with what may be termed an in-line connector, in which multi-socket outlets are provided in a connector body which has a wire leading from it and provided with a plug for connecting to a mains socket to provide electrical input to the connector. We are also concerned with providing an adapter type connector where the connector is provided with pins for plugging directly into the mains outlet socket. In such cases the configuration of the connector may be the same as for the inline type say with two or more sockets disposed in a body side by side or another convenient configuration may be utilised. There is also contemplated a single inline connection for extension purposes. Each of the aforementioned types of connector/socket is intended for use with the described plug and to make use of the aforedescribed advantageous assembly and disassembly proceedures.

Another aspect of the invention concerns the way in which pins are held in the plug. Currently 13 amp 3-pin plugs are in two parts which allow pins to be fitted into one part and then retained in position by fixing the second part to the first, the separation of parts also serving to allow access for wiring up the plug. Such a construction can present difficulties in assembly and the present invention aims to provide a solution by having the plug body moulded with apertures to receive pins on a push fit basis and to provide cooperation between the body and the pins once introduced therein. A simple way of doing this is to have a rib in the moulding with which terminal connection provision of the pins cooperate when the pins are in position so preventing withdrawal. The plug may then be provided with a simple cover to allow access to the terminals for wiring up.

A yet further aspect of the invention is concerned with providing electrical connection to the socket terminals of the connector for receiving the plugs, from the input wiring or direct pins.

Known in-line 13 amp 3-pin flat connectors have used flexible wiring for the socket terminals. The soldering up of same and assembly into the socket/connector body necessarily increases assembly time.

The present invention aims to overcome that by providing hard wiring of the terminal, to electrical conduction straps. However, this in itself can cause difficulties in achieving satsifactory cross-over, and this has been solved by providing for at least certain of the conductor strips to be stepped at different levels within the connector. In fact we prefer the neutral, live and earth connectors each to be at different levels relative to one another.

A yet further aspect of the invention concerns the method of assembly of shuttering for electrical socket connections of the connector. In this regard an advantageous construction results from having the connector body mould split in a plane intersecting the three pins, thereby facilitating emplacement of the shutters and electrical conductors for the sockets into one half of the connection body before securing the other half to it. The shutter can be easily retained by providing detent parts acting as retention means.

Actuation of the shutters is adantageously achieved by the plug pin shroud with spring means acting between the shutters to urge them outwardly.

According to a yet further aspect of the invention there is provided a method of assembling a shuttered electrical socket wherein a socket body of insulating material is apertured to receive shutters for electrical contacts to live and neutral and wherein the apertures are open to the side of the socket and the shutters are inserted into the aperture by way of the respective opening from the exterior of the socket, with deformation of resilient retaining means, and thereafter relaxing of the retaining means serves to retain the shutters in the apertures.

More particularly the shutters themselves incorporate the resilient retaining means in the form of resilient detents. A spring acting between two shutters serves to urge them outwardly, and the spring is installed prior to or with the shutters, usually received in a bore of one shutter on assembly of same.

The aforementioned shutter construction preferably finds application in a socket construction and especially that envisaged for a 4-way plug-in type adapter where the socket assembly allows such side ways assembly of the shuttering and is separate from the surrounding shrouding.

Another aspect of the invention concerns an adapter in which multiple sockets are positioned to the bottom thereof, preferably all on the same level, say in a 2 x 2 matrix and adapted to receive the aforedescribed plugs with guide extension. The casing of the adapter shrouds the four sockets as a group.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a fragmentary perspective view of a plug assembled in a four way connector; Figure 2 is a fragmentary perspective view of the plug and connector of Figure 1 before connection; Figure 3 is a plan view of one embodiment of 4 way connector; Figure 4 is an end view in the direction of arrow A of Figure 3; Figure 5 is a plan view of Figure 3 showing internal detail with pin wiring terminals omitted; Figure 6 is a plan view of terminal wiring for assembly into the socket of Figure 5; Figure 7 is an end view in direction of arrow B of Figure 6; Figure 8 is a side view in direction of arrow C of Figure 6; Figure 9 is a section view on IX-IX of Figure 5 showing terminal conductor wire positions; Figure 10 is a plan view of a plug;; Figure 11 is a sectional side view of the plug of Figure 10 with pins omitted; Figure 12 is an end view of the plug in the direction of arrow D of Figure 11; Figure 13 is a view of a shutter assembly for a socket of a connector; Figure 14 is a section on X-X of the plug of Figure 11 showing pins in position and retention ribs therefor; Figure 15, 16 and 17 shows respective plan, side and end views of a socket shutter; Figure 18 is a perspective view of a basic socket unit; Figure 19 is a side view of a 4-way plug-in type adapter with plugs in position; Figure 20 is a front view of the adapter of Figure 19; Figure 21 is a rear view of the adapter of Figure 19 with plugs omitted; Figure 22 is a cross-sectional view of the adapter showing socket detail; and Figure 23 is an underneath view of the adapter, omitting pins.

Referring to the drawings, there is illustrated one embodiment of plug, a connector of in-line type actually shown as a 4-way but could be more or less depending on the number of socket outlet provisions, and a 4-way plug-in type connector. The basic configuration of plug and socket corresponds to the flat 3-pin type currently used in the British market for electrical appliances such as kettles, slow cookers and the like, usually in such applications the socket serves as the electrical input to the appliance and is on the end of a wire connected to a 3-pin 13 amp plug for plugging into mains wiring electrical socket.

The illustrated embodiment of 4-way in-line connector will be described first. It comprises a body 1 formed in two halves 3, 5 conveniently referred to as upper and lower parts. These are formed as a plastics moulding providing socket provision 7 (four in the illustration) for plugs 59 illustrated further with reference to Figures 11 to 14 and described further herein below. The plug has a body 11 from which 3 pins 12 (one each for live, neutral and earth) project (see Figure 14) and the pins are surrounded by a shroud 13 which is formed as an extension from the body. Also extending from the body is a guide extension member 15 shown spaced by gap 17 from the shroud in the illustrated design, but in the alternative, could be an extension thereof.The plug body is moulded in one piece, save for a cover 19 received in a cutout therefor and secured in place by screw means through hole 21 into reception bore 22. The pins 12 each has terminals 23 as part thereof which are provided with screw means for securing electrical wires thereto. A cable clamp is shown as 24 with the plug being apertured at 23 for pasage therethrough of the cable/flex from the appliance. It will be noted that the body has through holes 26, one for each pin, to allow the pins to be inserted axially from the inside of the plug in the direction of arrow E (see Figure 14). The mould to the said holes has a rib formation 28 with which the terminal engages when in its installed position, with the terminal then retained in position. The terminals can be pushed past the rib for installation purposes.

Also of particular note are the recesses 29 to the exterior of the guide extension member to from abutment surfaces with which a person installing the plug or more especially removing it can gain frictional contact with a finger or thumb. The purpose of this will be described further hereinafter.

Referring again to the connector 1, it will be seen that the socket provisions for receiving the aforedescribed plug comprises a moulded body 31 corresponding substantially in cross-section to the internal aperturing of the pin shroud 13. Thus the plug shroud fits around the socket projection and with the pins of the plug received in the terminals of the socket. Each socket projection is itself accommodated within spaced shielding members comprising a base wall 33 a top wall 35 and side walls 37. The spacing 39 is dimensioned to receive the cross-sectional shape of the shroud 13.

It will be noted that the base wall 33 extends beyond the end face 41 of the socket and that extension thereby serves as an abutment and guide for aligning the plug with the socket. That guiding is also aided by the side walls 37 which is will be seen also extend above the level of the top wall 35 so as to provide guide rails 43. Thus, it will been seen by reference to Figure 2 that the cooperation of the guide extension 15 of the plug with the guide rails 43 aids alignment of the plug with the socket, which is advantageous where the connection has to be made in areas of limited access. The base wall extension 33 further assists in this regard. It will be noted that all pins and sockets are shielded so that the likelihood of electrocution is eliminated.

A particular advantage of the plug and connector construction arises when it is required to remove the plug. Instead of having to grip the plug body and pull to remove it, the shape of the connector allows contact with the plug to the opposite side of the connector to the direction of "plugging-in" so that contact of the guide extension 15 by a finger or thumb allows the plug to be pushed, whilst the operator may take the reaction against the socket. Note also in the illustrated embodiment the fact that the guide extension extends beyond the far edge of the connector - see 45 in Figure 1 -, which further assists in release - such as by pressing on the end 47 of the guide extension 15 say with the thumb and with fingers contacting the socket entry side of the connector. This facilitates release of the plug with a squeezing action.

By making the connector body in two halves 3, 5, terminal connections and shutters for the live and neutral terminals of the sockets may simply be assembled into place before securing the two parts together - such as by sonic welding. Each socket projection has recessing 49 for contacts to receive plug pins, and in the case of live and neutral these have recessing 40 to receive end shutters 51. The shutters themselves are illustrated in Figures 15 to 17 whilst their assembly is shown with reference to Figure 13. Essentially they comprise insulating blades having appertures 53 dimensional for the passages therethrough of plug pins when aligned therewith, a detent 55 having a shoulder 56 to prevent their outward movement past side walling 57 of the socket mouldings under the action of a spring 60 using two shutters apart and seated in bores 61.A chamfered actuating part 59 is arranged to extend beyond the socket wall into space 39 for contact by the plug shroud to actuate the shutters for alignment of their apertures with the plug pins to allow insertion of same. The shutter can simply be placed into the recesses 40 therefor, before fitting the top part in place and of course that is done after all other parts have been fitted in place as described below.

The contacts of the sockets for the plug pins are shown at 61 in Figure 6 and comprise suitable conducting materials usually having birfurcated resilient tags. These are soldered, rivited or otherwise securely fixed to conduction rails shown as 63, 65 and 67 for live, neutral and earth respectively.

These are substantially strip-like members, which makes for ease of assembly compared with the alternative connection of contacts 61 to flexible insulated wiring.

By controlled spacing of the conduction strips the need for additional insulation can be avoided, so further reducing costs. We find this can be done by having the respective conductor rail 63, 65, 67 stepped within the body, i.e. at different levels. For this purpose the bottom part 5 of the connection has staging 71, 73 75 at a different level for each of the respective conduction rails - as seen from Figure 9. The connections of the conduction rails to the contact 61 and the terminal connection thereto, 81, 83, 85 can then allow for suitable offsetting, as shown with reference to Figures 7 and 8. It will be seen that the live conductor passes to the terminal 81 by way of fuse connections 87, 88. Thus, it will be seen that the conductors bridge one another without need for insulation.Holes 89 allow for fixing of conductors to the staging of the body by way of plastic pegs suitably headed using heat deformation after assembly of conductors. The top part 3 provides an access cover 92 to the terminals 81, 83, 85 and a fuse block 91.

The above described connector block has 4-in-line sockets. In addition we also envisage providing a larger connector, with six sockets, in-line, but otherwise of identical construction.

It is also envisaged that the connector may in its more basic form simply comprise a single socket as illustrated diagrammatically with reference to Figure 18. That connector provides a single socket 31' accommodated within a spaced shroud comprised of bottom top and side walls 33', 35' and 37' respectively, and being configured like a single socket version of the aforedescribed connector so as to further provide guide rails 43'. The side of the connector opposite to the socket entry is apertured for passage through of a flex 44'. Such a connector can serve as a socket in an extension lead. It is a straight forward matter to envisage multiplication of socket provisions as required.

A yet further embodiment of connector is described with reference to Figures 19 to 23, which illustrate a plug-in type 4-way connector. The connector has a body 100 accommodating three pins (13 amp flat pin type) for connection into a mains electrical outlet socket of known type. The body has four sockets 101 of the aforedescribed type which emerge from the base of the adapter in the illustration, all disposed at the same level. The sockets are surrounded by a shroud 103 made up of the lower edge of a support plate 105 and the lower edges of a 3-dimensional cover 107. The sockets 101 are formed in pairs by identical moulded plates 109 disposed side by side (see Figures 22 and 23). A circuit board 110 has contacts 61' secured directly thereto which are received in apertures 112 therefor in the socket moulding. Each socket has at least for live and neutral contacts, shuttering.The shutters are as described with reference to Figures 15 to 17 and are actuated by the shrouds of the plugs as previously described. However, they are assembled differently. In fact they are pressed into position from the exterior of the socket moulding by way of the openings 114 through which the ends 59 will project. The detent 55 is resilient, so as to collapse inwardly on assembly allowing the shutter into the aperture 112. Once in place the detents expand back to their original position so that the shoulder 56 then prevents the shutters from moving outwardly more than prescribed by contact of the shoulder 56 with the socket moulding wall. A spring is fitted into the bore 61 of the shutter prior to assembly into the socket, and this serves to ensure that the shutters are urged outwardly.

Figure 21 shows the back view with flat pins 130 and fuse holder 132. Figure 19 shows an external side view showing the three pins 130 projecting from the plate 105, and two plugs in their fitted position.

Figure 20 shows the corresponding front view with two plugs to each side. It will be seen that in this embodiment the extension guide arms of the plugs do not extend beyond the socket body but terminate where they body starts to taper. Nevertheless this allows for the end extension to serve as an abutment to receive a pushing force to disengage the plugs.

The pins 130 are carried from a mounting plate 134 which also carries insulated sleeving 136 in which the respective pins are received, with that for the live and neutral projecting from the plate 105. The circuit board 110 and two socket mouldings are located by ribbing 138 of the plate 105 and cover 107.

Claims (42)

1) An electrical connector comprising at least one plug and socket in which the plug has a body member which presents an accessible abutment when the plug is inserted in its mating socket, which abutment can take a pushing force to facitate release of the plug from the socket.

2) A connector as claimed in claim 1 in which the plug body is provided with an extension for use in guiding the plug into its mating socket.

3) An electrical connector comprsising at least one plug and socket in which the plug body is provided with an extension separate from its pins for use in guiding the plug into its mating socket.

4) A connector as claimed in claim 2 in which the abutment is on the extension of the plug member.

5) A connector as claimed in claim 2, 3 or 4 in which the extension is aligned in parallel with pins of the plug.

6) A connector as claimed in claim 5 in which the extension extends up to or beyond the end of said pins, at least for live and nuetral.

7) A connector as claimed in any one of claims 2 to 7 in which the extension of the plug is greater in length than the depth of the socket when measured from the socket receiving face.

8) A connector as claimed in any one of claims 2 to 7 in which the socket is provided with ribbing and/or shoulders extending in the direction of plug/socket connecting engagement and which are cooperable with the extension for guide purposes.

9) A connector as claimed in any one of the preceding claims comprising a shroud for the pins of the plug.

10) A connector as claimed in claim 9 in which the pin receiving body of the socket is shrouded with spacing therebetween to receive said plug pin shroud.

11) A connector as claimed in any preceding claim in which the socket has an extension forward of its pin receiving socket face, which extension acts as a guide to align the plug and socket on installation.

12) A connector as claimed in any preceding claim in which multiple socket outlets are provided and wherein a flying lead is provided for electrical connections to the sockets.

13) A connector as claimed in claim 12 in which said multiple sockets are disposed in line side by side.

14) A connector as claimed in any one of claims 1 to 11 in which the socket body has multiple sockets and integral plugs, eg. 13 amp 3 pins, type for fitting into a mains electrical socket.

15) A connector as claimed in claim 14 in which at least two sockets are provided and accessed in a direction normal to the integral pin axis, and preferably facing downwardly relative to a horizontal pin axis.

16) A connector as claimed in claim 15 in which four sockets are provided mounted in two pairs side by side2 and having their socket faces in the same plane.

17) An electrical connector constructed and arranged substantially as hereinbefore described with reference to and as illustrated in figures 1 to 17, or 18 or 19 to 23.

18) A plug construction having a plug body with apertures therein to receive a respective pin on a push fit basis and wherein cooperating rib means provide cooperating interengagement between the pins and the plug body to retain the pins in position.

19) A plug construction as claimed in claim 18 in which each aperture has at least one rib or lip which presents a shoulder facing opposite to pin insertion direction to act as retention for the pins.

20) A plug construction as claimed in claim 19 in which the rib or lip is resiliently deformable to permit passage of the pin part in the insertion direction.

21) A plug construction as claimed in claim 20 in which the shoulder lies adjacent to the inward end of the pin.

22) A plug construction as claimed in any one of claims 18, 19 or 20 in which a plurality of saw tooth-like ribs are provided to one or two sides of the pin and the pin has cooperating formations.

23) A plug construction substantially as hereinbefore described with reference to the accompanying drawings of Figure 14.

24) An electrical socket connector having multiple socket outlets and connections for electrical supply to said sockets wherein wiring conenctions for such as live neutral and earth is by means of hard wiring as conductor strips, and wherein at least certain of the conductor strips are stepped at different levels within the conector.

25) A conenctor as claimed in claim 24 in which each of the neutral, live and earth conductors are at different levels and spaced one behind the other relative to socket outlet position thereby permitting wiring conductors to cross.

26) An electrical socket connector constructed and arranged substantially as hereinbefore described with refernce to and as illustrated in Figures 5, 6, 7, 8 and 9 of the accompanying drawings.

27) A method of assembling a shuttered electrical socket, having a socket body which is apertured to receive shutters for electrical contacts to live and neutral and wherein the apertures are open to the side of the socket, the method comprising inserting the shutters into the aperture by way of the resepctive opening from the exterior of the socket with deformation of resistant retaining means, and thereafter releasing of the retaining means serves to retain the shutters in the apertures.

28) A shuttered socket having a socket body which is apertured to receive shutters for electrical contacts to live and neutral in which the apertures are open to the side of the socket, and resilient retaining means providing cooperable surfaces which permit assembly and thereafter act to retain the shutter by cooperation of facing surfaces.

29) A shuttered socket as claimed in claim 2 in which the shutters in corporate resilient retaining means as a resilient detent.

30) A shuttered socket as claimed in claim 28 or 29 in which a spring acts between the two shutters to urge them outwardly.

31) A shuttered socket as claimed in claim 30 in which the shutters are urged by the spring into a position in which they extend beyond sides of the socket for actuation inwardly by a cooperating plug part.

32) A shuttered socket constructed and arranged and adapted to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings of Figures 13 and 15 to 17 in conjunctiion with Figures 19 to 22.

33) An electrical connector comprising a housing having pins for plugging into a mains electrical outlet and a plurality of socket outlets disposed in said housing and presenting socket faces downwardly relative to horizontal pin orientation for a normal 3-pin plug, and wherein said socket faces are all on the same level.

34) An electrical connector as claimed in claim 33 in which the socket outlets are mounted in pairs back to back.

35) An electrical conenctor as claimed in anyone of claims 33 to 34 in which the housing shrouds the sockets as a group.

36) An electrical connector as claimed in any one of claims 33 to 35 and adapted to receive a plug with a guide extension.

37) An electrical connector constructed and arranged substantially as hereinbefore described with refernce to and as illustrated in the accompanying drawings of Figure 19 to 23.

38) A plug for mating with an electrical socket,the plug comprises a body having an extension in the direction of its pins, which extension serves as a guide for mating engagement of the plug with the socket and/or as an abutment to facilitate release from a mating socket.

39) A plug as claimed in claim 38 in which the extension is disposed spaced outwardly of the pins and substantially parallel thereto and is substantially planar.

40) A plug as claimed in claim 38 or 39 further comprising a shroud around the pins.

41) A plug as claimed in claim 40 in which the shroud is spaced from the extension.

42) A plug constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings of figures 10, 11 and 12.