EP2194617A1

EP2194617A1 - Socket-outlet

Info

Publication number: EP2194617A1
Application number: EP09175187A
Authority: EP
Inventors: Mauri Parviainen
Original assignee: ABB Oy
Current assignee: ABB Schweiz AG
Priority date: 2008-11-28
Filing date: 2009-11-06
Publication date: 2010-06-09
Anticipated expiration: 2029-11-06
Also published as: FI20086143A0; EP2194617B1; DK2194617T3; FI120925B

Abstract

The invention relates to a socket-outlet. A body (3) of insulating material is formed with mounting brackets (2) for fixing the body (3) to a supporting structure. Metallic terminal units (4) include first connectors (4.1) fitting for contact with the prongs of electric plugs and second connectors (4.2) intended for contact with electric wires. A housing component (1) constitutes a cover or enclosure which conceals an internal component (5) of the socket-outlet. The socket-outlet's internal component (5) comprises at least the body (3) and the terminal units (4). The first connectors (4.1) are shaped as two-way funnels for receiving the prongs of electric plugs from two opposite directions, whereby the relevant terminal unit (4) can be used both in surface-mount and concealed socket-outlets. In addition, the socket-outlet comprises an upper earth terminal unit (9) and a lower earth terminal unit (10) present at an end wall of the body (3). The mounting brackets (2) are provided with rupture weaknesses (2.2), which are positioned in such a way that, as the mounting brackets rupture, the live components remain protected.

Description

The invention relates to a socket-outlet, comprising a body of insulating material, mounting brackets shaped thereon for fixing the body to a supporting structure, metallic terminal units, including first connectors fitting for contact with the prongs of electric plugs and second connectors intended for contact with electric wires, and a housing component constituting a cover or enclosure which conceals an internal component of the socket-outlet, the socket-outlet's internal component comprising at least the body and the terminal units.
The connecting directions of conductors in diverse type socket-outlets vary a great deal as manufacturers aspire to make the installation of socket-outlets as easy as possible.
In a prior known design for concealed socket-outlets, these are brought directly or in an inclined orientation from behind the socket-outlet. In another design for a surface-mount socket-outlet, the conductors are brought respectively from ahead of the socket-outlet. This leads to the need of making two separate sets of connectors for these discrete installation cases, because both require on the front side a funnel type or conical element apt for receiving an electric plug.
Another prior known solution for the above problem is to bring conductors to a connector directly from the side, whereby one and the same connector can be used in socket-outlets applicable to both concealed and surface mounting. A weakness in this solution is that the installation becomes more difficult in comparison with the solution described earlier. As a result of terminal structures, the internal component of a socket-outlet becomes quite sizable. It is because of a large size of the internal component and the conductors arriving straight from the side that, in concealed installation, such a socket-outlet is difficult to fit in an instrument box. In addition, the installation of a socket-outlet requires that the internal component be threaded securely onto socket screws. Consequently, the conductors arriving from the side must be subjected to vigorous bending and may detach or damage. In surface mounting, the conductors coming from the side are difficult to connect as the conductor openings will be located in a blind spot between the earth terminal and the corners of the body. This is a nuisance, especially in installations conducted in the immediate vicinity of a side wall, a floor or a ceiling, because in that situation there is no way of having an unobstructed view from all sides. A comparatively sizable internal component, resulting from this compromised design, is inconvenient to use in all installation cases.
A socket-outlet of the above-mentioned type is known from the Applicant's patent publication FI 115090 . In that solution, the safety of a socket-outlet has been improved by means of a construction which ensures that the socket-outlet interior, once installed, provides screen protection without a housing component. The advantage of this solution, in the case of concealed installation, is achieved by bringing the conductors in obliquely from below, which is convenient from the standpoint of installation. However, this prior known socket-outlet involves the drawback that terminal units for surface-mounted and concealed socket-outlets must be manufactured separately and in mutually different designs as described above, because the electric wires to be connected must be brought in from different incoming directions.
This type of socket-outlet, in which the conductors are brought in obliquely from below, could also be used in surface mounting. In this case, however, it would be necessary to provide a sufficient space for conductors under the internal component of a socket-outlet, resulting in the socket-outlet with a considerable height. Furthermore, in surface mounting, the installation would have to be conducted by using a method employed in concealed installation, wherein the conductors are connected to a presently loose internal component, which would be subsequently attached to its supporting structure. This mode of installation involves a hazard of conductors becoming loose or damaged. In addition, the coupling of previously wall-mounted installation cables and the cutting thereof to a suitable length would be particularly difficult in the installation conducted on a loose internal component of the socket-outlet.
The above design is further limited by stringent standard size regulations for socket-outlets to be mounted on concealed installation boxes. The solution of the invention enables distinguishing socket-outlets made for concealed installation, which are subject to these standard size regulations, from socket-outlets intended for surface mounting, which are not restricted by the stringent size regulations of a concealed installation box. Nevertheless, it will be possible to use a terminal solution described in the above-mentioned patent publication ( FI 115090 ), with its obliquely extended conductors, both in voltage terminals and also in an end-wall mounted earth terminal.
It is an object of the invention to find a solution which enables the elimination of these drawbacks. The solution is presented in the appended claim 1.
Another drawback in said prior known socket-outlet is that the solution presented therein for connecting earth conductors is poorly applicable to socket-outlets intended for surface mounting, because the conductors are located in a blind spot within the body and the result will be a high socket-outlet design. It is an additional object of the invention to eliminate these problems in such a way that earth conductors are also readily connectable while maintaining the socket-outlet's internal component as low as possible. The solution to this problem is presented in claim 2.
As a result of their relatively high design, the surface-mount socket-outlets may occasionally be exposed to a particularly high external load, which exceeds the strength regulations imposed on such a structure and which may rupture the structure. In this case, it is important that the rupture should occur safely so as to preserve adequate protection for live components. This safety-improving objective is attained by the solution presented in claim 3.
The dependent claims 4-10 present other preferred implementations and configurations of the invention.
The invention will now be described in more detail by way of working examples with reference to the accompanying drawings, in which

Fig. 1: shows a surface-mount socket-outlet of the invention - in this case in a 2-gang version - equipped with an enclosure type housing component 1;
Fig. 2: shows the socket-outlet of fig. 1 in an opened condition and with a top 1a and a bottom enclosure 1b of the housing component 1 disengaged from each other, and with an internal component 5 at- tached to the bottom section 1b;
Fig. 3: shows a 4-gang surface-mount socket-outlet - the housing com- ponent 1 consists of a cover enclosure 1a and 1b;
Fig. 4: shows the enclosure bottom 1b for a socket-outlet equipped with the cover enclosure of fig. 3, upon which is mounted two 2-gang internal components 5 by means of screws 15;
Fig. 5: shows a 2-gang internal component for a socket-outlet in a view obliquely from above;
Fig. 6: shows the internal component of fig. 5 from a different angle of view;
Fig. 7: shows the same internal component as figs. 5 and 6, but in a view obliquely from below;
Fig. 8: shows a body, along with its terminals, included in the internal component 5 of figs. 5-7, with an insulator element 6, 8 removed from top of the body and the terminals;
Fig. 9: shows the same as fig. 8, but with an upper earth terminal unit 9 lifted up off its position;
Fig. 10: shows the same as figs. 8 and 9, but with the upper earth termi- nal unit omitted and other terminal units lifted up;
Fig. 11: shows the same as fig. 8, but with the upper earth terminal unit 9, a grounding top 11, and an end terminal unit 10 (= a lower earth terminal unit, subsequently referred to as the end terminal unit) lifted up and with terminal units 4 mounted on a body 3;
Fig. 12: shows the same as fig. 11, but in a view from the perspective of an end wall provided with the end terminal unit;
Fig. 13: shows the terminal unit 4 of a socket-outlet, two of which are in- stalled in parallel and spaced from each other in receptacles 3.4 of the body 3;
Figs. 14 and 15: show the terminal unit of fig. 13 in views from various per- spectives;
Fig. 16: shows the upper earth terminal unit 9 of a socket-outlet;
Fig. 17: shows the end terminal unit 10, which comes to contact with the upper earth terminal unit 9 and which functions as a terminal for earth conductors;
Fig. 18: shows the end terminal unit of fig. 17 in a view from another per- spective; and
Figs. 19 and 20: show the use of one and the same terminal unit 4 in con- cealed socket-outlets. In this case, the prongs of an electric plug arrive in connectors 4.1 from a direction other than in the configu- ration depicted in other figures. The wires to be attached to con- nectors 4.2 are brought obliquely from below by way of openings 3.1 in a body 3'.

The main components of a socket-outlet according to the invention are a housing component 1 with its top and bottom sections 1a, 1b, a body 3 of insulating material, including mounting brackets 2 which are shaped as extensions of the body 3, metallic terminal units 4 for conducting power from electric wires to the prongs of an electric plug, an upper earth terminal unit 9 and an end terminal unit 10 for earth conductors used for conducting earth from the earth conductor to the earth connectors of an electric plug (in this case Schuko, but implementable also with socket-outlets of other standards), an insulation component 6, which in the present working example constitutes at the same time the base of a child protection element, child protectors 7 and a top 8 of the child protector, as well as a top 11 of the end terminal unit 10.
The foregoing components, except for the housing component 1, make up an internal component 5 assembled for a single package, which houses all technical aspects essential in terms of service and safety of the socket-outlet and which internal component 5, once installed, is adequately protected in electrical sense without the housing component 1. Consequently, the housing component 1 may come in various versions, e.g. for complying with various installation conditions (a dry space, a wet space, indoors, outdoors, etc.), for reasons of appearance (color, shape, type of surface, etc.) or for creating diverse product variations.
The following description deals in more detail with each of the foregoing main components or elements.
The body 3, depicted in figs. 8-12, is provided with two elongated, flared-end recesses 3.4 used for receiving terminal units 4 subsequently described in more detail. The terminal units 4, and an upper earth terminal unit 9 to interposed therebetween, are set at a distance from each other in an electrically insulated condition. The body's other end features a recess 3.5 used for receiving an end terminal unit 10 including connectors 10.2, which, by way of the terminal unit 10, are in contact with the earth terminal unit 9 and into which the connectable earth conductors are insertable either from the socket-outlet's end wall side or obliquely from the front wall side (the incidence angle of conductors may range from vertical all the way to horizontal on both front and rear sides). Therefore, the end terminal unit 10 has its top 11 provided with holes 11.1 providing a desired incoming direction for conductors.
The child protector's top 8 and the insulation component 6 have their side edges provided with holes 8.1, through which the electric conductors can be brought obliquely from the front of a socket to connectors 4.2. By virtue of a conical flare in the diagonal holes 8.1 and 11.1 and the inclination of other surfaces as well, it is possible to use a simple mold without expensive lateral cores.
By virtue of beneficial inclination angles exhibited by the components' contacting surfaces, the terminal units and the insulating unit can be installed on the body directly from above. The body 3 has mounting brackets 2 on its sides for fastening screws 15 or clamping claws. The mounting brackets 2 are provided with rupturing weaknesses 2.2, which are positioned beyond those walls of the body 3 which limit the outer sides of the terminal units 4. The weaknesses 2.2 are also built inside the mounting bracket in the recess for establishing a weaker line of rupture. Thus, in the event that the mounting brackets 2 rupture as a result of the socket-outlet being subjected to an exceptionally powerful external load, the live components shall remain protected.
The terminal unit 4 depicted in figs. 13-15 - in this embodiment that of a 2-gang socket-outlet - includes first connectors 4.1 fit for contact with the prongs of electric plugs and second connectors 4.2 intended for contact with electric wires. The first connectors 4.1 are shaped as two-way funnels for receiving the prongs of electric plugs from two opposite directions. As a result, the same terminal unit 4 can be fitted in a concealed socket-outlet in such a way that electric wires can be connected from the socket's bottom side, which is beneficial from the standpoint of installation. This is shown in more detail in figs. 19 and 20, which visualize an installation of the terminal units 4 from another direction in a concealed socket-outlet with openings 3.1 for conductors located in the side edges of the bottom. (In fig. 20, the surface socket's counterparts 1, 3 and 5 are designated as 1', 3' and 5'). The terminal unit 4 is constructed in two segments, namely a connector spring 4.3 and a double-folded sheet segment, which constitutes a terminal body and which features several bends for establishing connectors 4.1 between the bent sheet sections. Several additional bends are included for establishing connectors 4.2 for electric wires and a closed ring with its edges 4.7 secured by snap-on couplings. The connectors 4.2 are designed as spring connectors by attaching the connector spring 4.3 to the unit 4, said spring including four pieces (the number can be anywhere within the range of 1...n) of bent spring connectors 4.4. At their ends are protrusions 4.5, which place themselves behind apertures present in the connectors 4.2. These protrusions or claws 4.5 can be acted on through apertures 13 in the body 3 for opening the spring connectors 4.2, 4.4. The connector spring 4.3 is attached to the terminal body by riveting through its apertures 4.6 with rivets made by drawing from the terminal body.
The upper earth terminal unit 9, depicted in fig. 16, consists of three elements. Two elements, provided with cradle guards 9.1, are attached to each other by means of a grounding bridge 9.2, which is riveted to the guard members with rivets 9.4 drawn from the actual cradle guard material. The grounding bridge 9.2 has its connector tab 9.3 establishing a contact with the end terminal unit 10, into whose connectors 10.2 the earth connectors can be inserted by way of holes 11.1 present in the gable edge of the top 11.
Figs. 17 and 18 illustrate an end terminal unit 10, which is constructed in two segments, namely a connector spring 10.3 and a sheet segment , which latter constitutes a terminal body and features several bends for establishing connectors 10.2 between the connector spring's tabs 10.4 and the unit's 10 body. The plurality of bends have been used to establish a closed ring, having its edges 10.9 clamped by means of snap-on couplings. The connectors 10.2 are configured to function as spring connectors by attaching to the unit 10 a connector spring 10.3 which, in this case, includes four pieces of bent spring connectors 10.4. However, the number of spring connectors may vary within the range of 1...n pcs. Their ends are provided with protrusions 10.5, positioning themselves behind apertures present in the connectors 10.2. These protrusions or claws 10.5 can be acted on by means of a press integrated with the socket-outlet assembly, as presented in the earlier patent publication FI-115090 , or directly by pressing with the tip of a screwdriver through apertures 13 in the body 3 for opening the connectors 10.2, 10.4. The connector spring 10.3 is fastened to the terminal body by riveting through its holes 10.8 with rivets made by drawing from the terminal body.
A contact tongue 9.3, included in the earth terminal unit 9, is capable of being pressed into a spring connector 10.1, set for receiving the contact tongue and included in the end terminal unit 10. A spring tongue 10.6, shaped on a connector spring 10.3 of the spring connector 10.1, is supported on a tongue 10.7 bent from the body of the end terminal unit 10. The terminal body 10 is formed by embossing with a space 10a, the depth of which is dimensioned such that the spring element 10.3 can establish with the contact tongue 9.3 a sufficient electrical contact. By means of rivet attachments 10.8, and the support tongues 10.6 as well as 10.7, a contact force sufficient to ensure a continuously reliable grounding contact. The embossed space 10a has its outset further provided with a short stretch of slightly broached space for providing a good starting guidance for the contact tongue before pressing it in. The slanting bends in the body of the end terminal unit 10 and in the spring 10.3 provide a good guidance for the contact tongue 9.3 and, because of the guidance, the contact tongue has its sides beveled and a chamfer punched on the sharp edges in a punching tool.
The end terminal unit 10 is covered with a separate safety top 11, whose color (e.g. green) is different from that of the insulating element 6, 8 covering the other terminal units 4. This provides guidance for connecting the earth conductors to correct connectors. The safety top 11 can be colored e.g. in colors (yellow or green) used as grounding symbols or in some other color used e.g. for information or protection purposes. In figs. 11 and 12, the top 11 of the end terminal unit 10 is visible in a condition uplifted from its position.
Figs. 5 and 6 show also a child protection element, having its bottom established by the insulation component 6 which, together with a cover 8 of the child protector, conceals the terminal units 4 and 9 along with their connectors, such that, once installed, the internal component 5 of a socket-outlet is sufficiently protected electrically (eliminating e.g. the risk of a feather-touch electric shock) without the housing component 1. On top of the insulation component 6 are spring-loaded child protectors 7 and the child protector cover 8 which includes spaces for receiving the child protectors 7, as described more precisely in patent FI-115090 . The child protectors 7 function on a familiar seesaw principle and are only able to move against the spring force when the prongs of an electric plug function through the socket holes simultaneously and in a balanced fashion on the child protector's 7 inclined surfaces.
The insulation component 6 and the cover 8 are also provided with holes for the penetration of a top section 1a and fastening screws 14 in order to enable these screws to engage with their screw thread in the bores of the body's 3 sleeves 3.6 (Fig. 9). Screen-protected insulation can also be established without child protection by means of an insulating element corresponding to the cover 8 or substituting for the cover 8 and the insulation component 6.
In the design of figs. 1 and 2, the housing component 1 may also consist of a closed bottom/top assembly along with its necessary grommets 16 and 17 made of a soft material. In this configuration, the internal component of a socket-outlet is pressed onto posts of the bottom section 1b and the appropriately dimensioned top 1a holds the internal component in place as soon as the fastening screws present in holes 18 of the top 1a have been threaded into screw posts 19 (in this case 4 pcs - may vary) of the bottom. This design provides a higher sealing class and, therefore, the top is also required to have a spring-loaded or otherwise closed flap cover 1c specific for each socket-outlet for protecting the connections e.g. from dust and water.
The insulation component 6 and the child protector's cover 8 are of course provided with through-holes for the prongs of an electric plug and for the cradle guards 9.1.
The child protector's cover 8 is provided with collar-like bosses 12 encircling the through-holes for the prongs of an electric plug and extending into the holes of the housing component 1. Thus, the material used for the housing component 1 need not satisfy such electrotechnical standards which are required of a material in contact with or supporting live metal components. As a result, the diverse housing components 1 of varying shapes or other features can be used for creating diverse product variations in which the internal component 5 remains the same.
The socket-outlet's structural aspects have been described as being consistent with Schuko plug and socket standards. The corresponding solutions according to these inventions can also be implemented in socket-outlets consistent with other plug and socket standards.
These solutions can be applied in 1-, 2-, 3-, 4-...n-gang socket-outlets both for permanent installation and also for the structures of extension socket-outlets. The described terminal designs include a solution with a connection for four conductors. However, the number conductors in the terminal is not limited, but it may vary within the range of 1...n.

Claims

A socket-outlet, comprising a body (3) of insulating material, mounting brackets (2) shaped thereon for fixing the body (3) to a supporting structure, metallic terminal units (4), including first connectors (4.1) fitting for contact with the prongs of electric plugs and second connectors (4.2) intended for contact with electric wires, and a housing component (1) constituting a cover or enclosure which conceals an internal component (5) of the socket-outlet, the socket-outlet's internal component (5) comprising at least the body (3) and the terminal units (4), characterized in that the first connectors (4.1) are shaped as two-way funnels for receiving the prongs of electric plugs from two opposite directions, whereby the relevant terminal unit (4) can be used both in surface-mount and concealed socket-outlets.
A socket-outlet as set forth in claim 1, in which said second connectors (4.2) are present on the sides of the body (3) and which includes an upper earth terminal unit (9), characterized in that the body (3) has its end wall provided with a lower earth terminal unit or an end terminal unit (10), which includes third connectors (10.2) which are in contact with the upper earth terminal unit (9) and into which the earth conductors to be connected are insertable either from the end-wall side of the socket-outlet or directly or obliquely from the front- or rear-wall side.
A socket-outlet as set forth in claim 1 or 2, wherein the mounting brackets (2) present on the sides of the body (3) adjoin the body walls limiting the outer sides of the terminal units (4), characterized in that the mounting brackets (2) are provided with rupture weaknesses (2.2), which are in such a way positioned outside the body walls limiting the outer sides of the terminal units (4) that, when the mounting brackets (2) rupture as a result of an exceptionally powerful external load acting on the socket-outlet, the rupture occurs along a rupture line established by the weaknesses and live components remain protected.
A socket-outlet as set forth in claim 2 or 3, characterized in that the end terminal unit (10) is concealed by a separate safety top (11), the color of which is other than that of an insulating element (6, 8) covering the other terminal units (4) and that of the body (3).
A socket-outlet as set forth in any of claims 1-4, characterized in that on top (3) of the body's front side is installed a separate insulating element (6, 8), which covers the terminal units (4) along with their connectors (4.1, 4.2), such that the socket-outlet's internal component (5), once installed, is sufficiently protected electrically without the housing component (1).
A socket-outlet as set forth in claims 2 and 5, characterized in that the insulating element (6, 8) comprises an insulation component (6), which is on top of the body (3) and on top of which are spring-loaded child protectors (7), and a child protector's cover (8), the body (3), the terminal units (4), the earth terminal unit (9), the end terminal unit (10) along with its safety top (11), the insulation component (6), and the child protectors (7) along with their covers (8) constituting the internal component (5), which is assembled for a single package and which houses all technology essential from the standpoint of a functioning socket-outlet.
A socket-outlet as set forth in claim 5 or 6, characterized in that the body (3) is configured with receptacles for the terminal units (4), the end terminal unit (10) and the upper earth terminal unit (9), in which the terminal units (4) and the upper earth terminal unit (9) are securely lockable by means of the insulating element (6, 8) including the child protectors, the end terminal unit (10) being covered by the separate and differently colored safety top (11).
A socket-outlet as set forth in any of claims 1-7, characterized in that each terminal unit (4) is constructed in two segments, namely a connector spring (4.3) and a double-folded sheet segment, which feature several bends for establishing the first connectors (4.1) and which, by means of several additional bends, are configured as a closed ring for establishing the second connectors (4.2) together with the connector spring (4.3) attached to the terminal unit (4), such that the conductors to be connected can be brought to the second connectors (4.2) obliquely from the front or rear side of the socket.
A socket-outlet as set forth in claim 7 or 8, characterized in that the insulation component (6, 8) has its edges provided with obliquely inward directed holes (3.1), as an extension of which the second connectors (4.2) place themselves after the terminal units (4) have been set in receptacles (3.4) of the body (3), and that the end terminal unit (10) has its safety top (11) provided with holes (11.1), as an extension of which the third connectors (10.2) place themselves after the end terminal unit (10) is set in a receptacle (3.5) of the body (3).
A socket-outlet as set forth in any of claims 2-9, characterized in that the earth terminal unit (9) has a contact tongue (9.3) and the end terminal unit (10) has a spring connector (10.1) receiving the contact tongue, the spring connector having its spring tongue (10.6) supported on a tongue (10.7) bent from the body of the end terminal unit (10).
A socket-outlet as set forth in any of claims 2-10, characterized in that the end terminal unit (10) has its body provided with an embossment (10a) for making space for the contact tongue (9.3), and that the embossed space (10a) has its outset provided with slightly broached space over a short distance for providing a good first guidance for the contact tongue prior to pressing it in.