[0001] 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.
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] The dependent claims 4-10 present other preferred implementations and configurations
of the invention.
[0012] 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'.
[0013] 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.
[0014] 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.
[0015] The following description deals in more detail with each of the foregoing main components
or elements.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
1. 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.
2. 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.
3. 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.
4. 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).
5. 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).
6. 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.
7. 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).
8. 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.
9. 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).
10. 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).
11. 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.