EP0281969B1 - Receptacle with additional module - Google Patents

Description

The invention relates to a built-in socket provided with an additional module according to the preamble of claim 1.

In a number of applications, it is useful to provide sockets with an additional module that z. B. provides overvoltage protection, a filter function, a relay or an electronic remote switch, or is provided with a residual current circuit breaker.

From DE-PS 25 46 868 a socket is already known, in which a residual current circuit breaker assigned to it is not only installed in a spatially adjacent wall mounting box, but is used for wall mounting a single, common wall mounting box. However, the space available in the installation box is only used by the residual current circuit breaker. In addition, the socket that can be plugged onto the residual current circuit breaker is made up of special parts that have to be created specifically for this type of socket.

From GB-A-1 214 678 a built-in socket with a support ring is known, on which a socket base is held via spacer bars. On the plug side, the socket base is covered by a plug pot provided with a cover frame and designed as a central piece. On On the installation side of the socket base, electronic switch-off means are arranged in side recesses provided for this purpose. This means that the socket base cannot be used in its usual form for the inclusion of an additional switching module, but must be specially adapted.

Based on this prior art, it is therefore an object of the invention to provide a built-in socket of the type mentioned, in which constructive measures are provided which allow the optional inclusion of an additional module in the socket without changes to a conventional socket base for sockets without additional module and enable simple attachment of the additional module to the socket base.

This object is achieved by the characterizing features of claim 1. Thereafter it is provided that the length of the spacer webs arranged on the support ring is such that the socket base is raised towards the support ring, but not beyond it, and its installation depth is reduced, so that the additional module the underside of the socket base and is held by means of clamp-like first latching hooks on projections of the socket base, that the top of the additional module adjoining the socket base is adapted to the underside of the base, and that the installation depth of the socket base provided with the additional module is the standardized minimum distance to the can bottom.

Due to the design of the top of the additional module, which adapts to the underside of the socket base, it is possible to reduce the installation depth of the socket compared to known designs with an additional module. At the same time, the clip-like first latching hooks allow the additional module to be anchored to projections of the socket base in a single operation, without this requires a change in the socket base. So that the additional module maintains a standardized minimum distance from the bottom of the socket when the socket is installed, the socket base must be raised compared to conventional sockets. However, this does not happen, as is known from the prior art, beyond the support ring of the socket resting on the installation wall, but only by means of shortened spacer webs connecting the socket to the support ring. This version remains thus maintain the socket in its basic structure, so that not only an unchanged base can be used, but the socket can also be used without an additional module.

Lifting the socket base also increases the distance between the top of the socket and the installation wall. In an effort to be able to take over another part of conventional sockets in addition to the socket base, you can choose between two alternatives. Either the cover frame remains unchanged, then the socket pot must be adapted so that it grips the cover frame with its outer edge and presses against the installation wall, or the socket pot remains unchanged, then the dimensions of the cover frame must be adjusted accordingly so that the protrusion of the plug pot compared to the installation wall. Furthermore, it is possible to manufacture the cover frame and the plug pot in one piece.

In a further development of the subject matter of the invention, the additional module is to be constructed in such a way that it consists of a few assemblies which are easy to combine. It therefore expediently consists of a lower housing part, an upper housing part and a circuit board inserted between the housing parts and carrying the electrical components. A particularly simple structure results from the fact that the latching hooks required for connection to the socket base are fastened to the upper housing part and preferably consist of flexible plastic from which the entire upper housing part is injection molded from the same material. These latching hooks grip the socket base on projections on which the spacer webs of the support ring are also fastened, since these are freely accessible starting from the underside of the socket base.

So that the additional module can be measured electrically in the event of a fault, it is advantageous that when the lower housing part is removed, the printed circuit board remains connected to the upper part and its conductor tracks are accessible. The lower part of the housing is therefore advantageously fastened by means of second latching hooks which, starting from the upper part of the housing, engage in window cutouts in the side wall of the lower part of the housing. The second locking hooks are molded onto the first locking hooks in the same material, but point in the opposite direction.

It is also advantageous that the rubber ring usually required for returning the expanding claws can be omitted when an additional module is attached. Its function is performed by two resilient tabs formed from the base of the lower housing part. They protrude flats on both sides of the side wall of the lower housing part such that the two expansion claws attached to the socket base each come to lie between a flattened portion and a tab. The tabs exert a spring force that counteracts the expansion of the expanding claws.

Special design conditions arise if the additional module is to be provided with an overvoltage protection circuit. Such an overvoltage module has the task of protecting the consumers connected to the socket from dangerous overvoltages. Such overvoltages can be caused by lightning strikes or switching operations in the network. Limiting the overvoltages to harmless values is achieved with the help of varistors, especially zinc oxide varistors (VDR = Voltage Dependent Resistors). In the event of high-energy voltage peaks, the varistor can be subjected to considerable surge loads, which not only endanger its function, but can sometimes lead to explosive destruction. To a certain extent it is possible with the help of an overcurrent release, e.g. B. a fuse, to prevent dangerously high current surges by interrupting the supply line, but such overcurrent releases do not always respond sufficiently quickly, so that the described risk can not be completely excluded.

In cooperation with a socket to which the overvoltage module is attached, this has a special function when the socket sockets are connected in series with the fuse. For example, the fuse can be blown due to a lack of voltage at the sockets of the socket. In this case, the overvoltage module can be replaced quickly while the socket can still be used.

With an overvoltage module that is connected to a consumer, it is not possible to provide a fixed assignment of phase and neutral. For this reason, it was necessary in the overvoltage module known from DE-OS 36 06 287 to provide it with a fuse in the two current-carrying lines. With a fixed assignment of phase, neutral and protective conductors, as is made possible in the combination of an overvoltage module and a socket according to the invention, a single fuse in the phase conductor is sufficient.

For the safety that the overvoltage module is to ensure, it is also of considerable importance that the fire risk associated with an explosion-like destruction of the varistors is reliably avoided. An expedient solution provides for the entire module to be filled with a poorly heat-conducting, mechanically resistant casting compound enclosing the electrical components. It is even more advantageous to provide the module with a separation chamber in which only the varistors at risk can be accommodated and then to fill this separation chamber with casting compound.

If you do not use a series connection of two varistors as usual, but replace them with a single varistor of approximately the same electrical value, it is possible to make the separation chamber and thus the whole module particularly small. The casting compound not only helps to avoid a fire risk, but also ensures a mechanical connection of the circuit board to the upper part of the housing.

To accommodate a gas discharge arrester, a bulge is also provided on the upper part of the housing, which is arranged in such a way that it comes to rest at a point left free by the socket base. Measures of this type made it possible to make the additional module provided for surge arresters from the underside of the socket base extremely flat.

A space-saving arrangement of the connection terminals takes place in a space which is not required by the socket base and which is on both sides of an earth bracket offset by 90 ° with respect to the spacer bars. Each of the three terminals for phase, neutral and protective conductors has two terminal contacts for connecting incoming and outgoing lines of the same potential.

For easy operation, the terminals are preferably screwless and can be operated from the connector side. On the opposite side, which faces the circuit board, they have contact pins with which they are soldered to the conductor tracks of the circuit board.

Furthermore, the terminals are each provided with inward locking edges, which allow the circuit board to be fixed before the filling of the casting compound creates a firm connection.

For the electrical wiring of the terminals to the socket terminals, openings are left on the upper housing part, which are used to lead through lines that are soldered to the circuit board at one end and rest at the socket terminals at the other end. The socket terminals are protected against unauthorized opening, e.g. secured with a varnish.

An embodiment of the invention is shown in the drawing and will be described in more detail below.

Fig. 1:

Die erfindungsgemäße Steckdose mit Zusatzmodul von der Seite im Schnitt,

Fig.2:

den Steckertopf von der Seite,

Fig.3:

den Tragrahmen von der Seite,

Fig.4:

den Steckdosensockel mit Tragring und angebautem Zusatzmodul von der Seite,

Fig.5:

die komplette Steckdose montiert von oben,

Fig.6:

die Leiterplatte des Zusatzmoduls von der Seite,

Fig.7:

die Leiterplatte des Zusatzmoduls von oben,

Fig.8:

ein komplett montiertes Zusatzmodul von der Seite im Schnitt, entsprechend der Schnittlinie nach Fig.9,

Fig.9:

das komplette Zusatzmodul von unten,

Fig.10:

die Schaltung eines Überspannungsmoduls.

Show it:

Fig. 1:

The socket according to the invention with additional module from the side in section,

Fig. 2:

the plug pot from the side,

Fig. 3:

the support frame from the side,

Fig. 4:

the socket base with support ring and attached additional module from the side,

Fig. 5:

the complete socket mounted from above,

Fig. 6:

the PCB of the additional module from the side,

Fig. 7:

the circuit board of the additional module from above,

Fig. 8:

a completely assembled additional module from the side in section, according to the cutting line according to Fig. 9,

Fig. 9:

the complete additional module from below,

Fig. 10:

the circuit of an overvoltage module.

As can be seen in FIG. 1, the basic structure of the socket consists of a socket base 1, which is held by a support ring 2, a plug socket 3, which protects the socket base 1 against contact on the plug side, a cover frame 4, which covers the installation opening of an installation wall W, and an additional module 5 fastened on the underside of the socket base 1, which is mounted together with the socket base 1 in a wall mounting box 9. The assembly is usually carried out by expanding claws 16, which are actuated by expanding screws 15.

In connection with Fig.1 one can see from Figures 2 to 5 that on the with expanding claws 16 in the Wall socket 9 held socket base 1, the plug socket 3, held by a screw, is placed and this in turn clamps the cover frame 4 to the installation wall W. Since wall mounting boxes with a standardized installation depth of 40 mm are not designed for the attachment of an additional module 5, various measures had to be taken to ensure the standardized minimum distance N between the socket and the box bottom 91 of the wall mounting box 9. For this purpose, the socket base 1 connected to the support ring 2 via spacer webs 21 was lifted from the socket bottom 91 by shortening the spacer webs 21. As can further be seen from FIG. 4, the already very flat additional module 5 is adapted with its top to the underside of the socket base 1, so that it connects directly to the socket base 1 with the aid of its clip-like latching hooks.

Before further details of FIG. 5 are discussed, reference is made to FIGS. 6 to 9. The various components of an additional module are shown in these, which are to ensure surge protection for the consumers connected to the socket.

The sectional drawing according to FIG. 8 reveals an upper housing part 6, a printed circuit board 7 and a lower housing part 8. According to FIGS. 6 and 7, a varistor 75, a fuse 77, a gas discharge arrester 76 and three connecting terminals 71, each with two clamping contacts 71a and 71b, are mounted on the printed circuit board 7 and are electrically connected via the conductor tracks (not shown). These components are each positioned so that they, as far as they over the cover level of the upper housing part 6th protrude, find space in free spaces that are not required by socket base 1. For the terminals, this space is parallel to the earthing bracket 13 in the extension of the insulating body 17 receiving the sockets. These points are also easily accessible on the plug side, so that the two electrically connected terminal contacts 71a, 71b of each connecting terminal 71, which are designed as screw terminals in the example, are easy to operate from the front of the socket.

The connection wires are fed in parallel to the socket bottom 91 of the installation box 9, each connection terminal being able to be connected to an incoming and an outgoing connection wire, so that the lines can be continued beyond the socket. With the conductor tracks of the circuit board 7, the terminals 71 are electrically connected via contact pins 72.

A further use of the free space remaining in the region of the socket base takes place through the gas discharge arrester 76, for which a bulge 67 is provided in the upper housing part 6. In order to thermally isolate the varistor 75 from the other components, a separation chamber 64 is formed on the inside of the upper housing part 6. This is filled with a casting compound 66 via a pouring hole 78 provided in the printed circuit board 7.

The additional module 5 is generally installed in such a way that the printed circuit board 7 is first created with the components mounted on it, then the upper housing part 6 is placed on the printed circuit board 7.

The upper housing part 6 is fixed with the aid of the connecting terminals 71, which project beyond the upper housing part 6 in the area of the recesses 63 provided for this purpose and each have a latching edge 79 on a side facing the upper housing part 6. The upper housing part 6 slides over this latching edge 79 when it is put on and is then held in its position. The subsequent filling of the separation chamber 64 with casting compound 66 results in a permanent connection between the upper housing part 6 and the printed circuit board 7. The subsequent fitting of the lower housing part 8 is achieved by means of second latching hooks 62 which are formed on the upper housing part 6 and engage in window cutouts 82 in the lower housing part 8 , facilitated. By pushing back the locking hooks, the lower housing part 8 can be removed at any time in order to make the circuit board 7 accessible for service measurements if necessary.

In an extension of the second latching hooks 62, first latching hooks 61 are formed on the upper housing part 6, which extend in the opposite direction to the latter and whose hooks lie opposite one another in the form of pliers. These second latching hooks 61 anchor themselves on projections 11 when the additional module 5 is unplugged onto the base 1. The projections 11 serve at the same time for fastening the expanding claws.

The two housing parts 6 and 8 are made of flexible plastic, which gives the locking hooks 61, 62 resilient properties. Likewise, two tabs 85 also spring, which grip the expanding claws 16 on both sides of the socket base 1 and press them against the base, so that they can only be spread against the spring force of the tabs 85. When loosening the expanding claws 16 the socket 1 can thus be easily removed from the wall mounting box 9.

In the area of the three recesses 63 of the upper housing part 6, in addition to the connection terminals 71 on the printed circuit board 7, corner pieces remain free, which are used for soldering lines 74, and thus enable a connection to the socket terminals 14 of the socket base 1.

The side wall 81 of the pot-shaped lower housing part 8 is provided on both sides in the area of the tabs 85 with a flattening, which reduces the diameter of the housing at this point and leaves space for the expanding claws 16. In addition, the side wall 81 is perforated in the area of the connection terminals in order to allow the supply lines to be fed.

.FIG. 10 shows the circuit diagram of an overvoltage module. On the network side, the phase conductor L, the neutral conductor N and the protective conductor are connected to the two-pole connection terminals 71 of the overvoltage module 5. All three lines lead via the printed circuit board 7 to the socket terminals 14, with only a fuse 77 being inserted into the phase conductor L. The sockets 17 are accordingly marked with Lʹ and Nʹ. Behind the fuse 77, a varistor 75 is arranged parallel to the sockets Lʹ, Nʹ, which also protects parallel consumers from dangerous overvoltages. A discharge gap 76 inserted between the neutral conductor and the protective conductor enables high-strength surge protection between all three conductors Lʹ, Nʹ and

.

The fuse 77 is matched to the varistor 75 in such a way that it normally blows first in the event of damage. As can easily be seen, the socket is de-energized, which is also possible without additional optical signaling, e.g. through a light, is easy to diagnose. In this case, the overvoltage module can be easily replaced due to its special design.

Claims (18)

1. Flush-mounted plug socket with a supporting ring (2), on which, via spacer webs (21), a plug socket base (1) is held, which is covered on the plug side by a plug receptacle (3), constructed as a central piece and provided with a covering frame (4), and has an additional module on its installation side, characterized in that the length of the spacer webs (21) arranged on the supporting ring (2) is such that the plug socket base (1) is raised up to but not beyond the supporting ring, and its build-in depth is reduced, in that the additional module (5) is arranged on the underside of the plug socket base (1) and held resting immediately against said base (1) by first latching hooks (61), formed in a bracket-like manner, on projections (11) of the plug socket base, in that the upper side of the additional module (5), bordering on the underside of the plug socket base, is adapted to the underside of this base, and in that the installation depth of the plug socket base (1) provided with the additional module (5) maintains the standardised minimum separation (N) from the socket base (91).
2. Flush-mounted plug socket according to Claim 1, characterized in that the plug receptacle (3), likewise raised due to the raising of the plug socket base (1), is either adapted so that it grips the covering frame, whose measurements are unchanged, and presses against the installation wall (W), or itslf remains unchanged and its projection relative to the installation wall (W) is compensated for by a suitably raised covering frame (4).
3. Flush-mounted plug socket according to Claim 1 or 2, characterized in that the covering frame (4) is gripped by the plug receptacle (3) such that it is fixed between this receptacle and the installation wall (W), or in that the covering frame (4) and plug receptacle (3) are constructed integrally.
4. Flush-mounted plug socket according to one of the preceding claims, characterized in that the additional module (5) comprises a housing lower part (8), a housing upper part (6), and a printed-circuit board (7), carrying the electrical components, interposed between the housing parts.
5. Flush-mounted plug socket according to one of the preceding claims, characterized in that the first latching hooks (61), which are required for connection to the plug socket base (1) and are made of flexible plastic, are fitted, preferably integrally, to the housing upper part (6).
6. Flush-mounted plug socket according to one of the preceding claims, characterized in that the first latching hooks (61) of the housing upper part (6) grip the plug socket base (1) on the projections (11), on which projections the spacer webs (21) of the supporting ring (2) are also mounted.
7. Flush-mounted plug socket according to one of the preceding claims, characterized in that both the printed-circuit board (7) and the housing lower part (8), which covers the printed-circuit board (7) in the form of a cup, are attached fixed by second latching hooks (62) in such a way that, with the housing lower part (8) removed, the printed-circuit board (7) remains connected to the housing upper part (6).
8. Flush-mounted plug socket according to claim 7, characterized in that the second latching hooks (62) are arranged on the housing upper part (6) and engage in window cut-outs (82) on the side wall (81) of the housing lower part (8), the second latching hooks (62) pointing in a direction opposite to the first latching hooks (61).
9. Flush-mounted plug socket according to one of the preceding claims, characterized in that the diameter of the housing lower part (8) in the region of the latching hooks (61,62) is reduced on both sides by a flattened area (83) on the side wall (81), and in each case one sprung tongue (85), projecting from the base (84) of the housing lower part (8) and integrally formed on it, projects beyond the flattened area (83) such that the expanding claws (16) mounted on the plug socket base (1) in each case come to rest between a flattened area (83) and a tongue (85), and the tongues (85) exert a spring pressure opposing the expansion of the expanding claws (16).
10. Flush-mounted plug socket according to one of the preceding claims, characterized in that the electrical components (71-77) of an overvoltage protection circuit are arranged on the printed circuit board (7), which overvoltage protection circuit has at least one over-voltage limiter (75), preferably a varistor, an overcurrent cut-out or limiter (77), preferably a melting fuse, and a discharge gap (76), preferably a spark gap.
11. Flush-mounted plug socket according to one of the preceding claims, characterized in that the power supply to the plug contacts (13,17) of the plug socket is effected in such a manner, that at least one overvoltage limiter is situated between the phase and neutral conductors (L, N) of the power supply cable, at least one discharge gap (76) is connected between the neutral conductor (N) and the protective earth conductor (13), at least one overcurrent cut-out or limiter (77) is inserted in the phase conductor (L) upstream of the overvoltage limiter (75), and if necessary a second overcurrent cutout and limiter (77) is inserted in the neutral conductor (N) upstream of the overvoltage limiter (75).
12. Flush-mounted plug socket according to one of the preceding claims, characterized in that the terminals (L, N) for the plug sockets (17) of the plug socket are connected in parallel with the overvoltage protector (75) downstream of the overcurrent cut-out (77), and the type of plug socket terminals (71), phase, neutral or protective earth conductor, is so identified on the plug socket that an unambiguous connection allocation results.
13. Flush-mounted plug socket according to one of the preceding claims, characterized in that the housing, preferably the housing upper part (6), has on its inside at least one chamber (64) in which all or individual electrical components (71-77) arranged on the printed-circuit board (7) are situated, and this chamber is filled with a potting compound (66) which is preferably a poor heat conductor and is mechanically resistant.
14. Flush-mounted plug socket according to one of the preceding claims, characterized in that the chamber (64) which is filled with potting compound (66) acts as a separating chamber, in which the overvoltage limiter (75) is situated, and is in consequence segregated from the other electrical components, and the potting compound (66) at the same time mechanically connects the printed-circuit board (7) firmly to the housing upper part (6).
15. Flush-mounted plug socket according to one of the preceding claims, characterized in that that the housing upper part (6) is provided with a domed depression (67) which allows space for a gas-discharge suppressor (76), and this domed depression (67) is arranged such that it is situated at a point which is exposed by the plug socket base.
16. Flush-mounted plug socket according to one of the preceding claims, characterized in that the space not required by the plug socket base, on both sides of an earthing bracket (13) offset at 90° to the spacer webs (21), is used for holding of connecting terminals (71), each of which has two terminal contacts (71a,71B) for the connection of connecting cables.
17. Flush-mounted plug socket according to one of the preceding claims, characterized in that the connecting terminals (71), which can also possibly be of the screwless type, are able to be operated from the plug side and are provided with contact pins (72) on the opposite side resting against the printed-circuit board (7), which pins are soldered to the printed-circuit board.
18. Flush-mounted plug socket according to one of the preceding claims, characterized in that both terminal connections (71a, 71b) of a connecting terminal (71) are in each case connected together electrically via the printed-circuit board (7), and the connecting terminals (71) projecting beyond the housing upper part (6) towards the plug socket base (1) are each provided with a latching edge, by means of which the connecting terminals (71), which are arranged in cut-outs (63) in the housing upper part (6), fix the latter to the printed-circuit board (7).

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