CN107112690B

CN107112690B - Socket with improved structure

Info

Publication number: CN107112690B
Application number: CN201580060904.6A
Authority: CN
Inventors: N·沙希尼安; H·富鲁
Original assignee: HOUSECONTROL AS AS
Current assignee: HOUSECONTROL AS AS
Priority date: 2014-09-09
Filing date: 2015-09-08
Publication date: 2020-02-11
Anticipated expiration: 2035-09-08
Also published as: ES2861357T3; EP3192132A1; CN107112690A; WO2016039631A1; EP3192132A4; NO337978B1; NO20141092A1; EP3192132B1

Abstract

A socket (100), the socket (100) comprising a cover (120), the cover (120) having a cylindrical well (130) with a diameter larger than the diameter of the surrounding cylinder (230) surrounding the existing predetermined plug (200), at least two contact holes (121) adapted to receive contact pins (211) for transmitting electrical power, wherein each contact hole (121) is positioned at the bottom of a recessed contact pin guide (141, 142). The ground terminal (112) is disposed in the well (130). When the plug is inserted into the well (130), contact pins on the plug slide along the recessed guides (141,142) towards the contact holes (121). The plug is thus rotated about the axis of rotational symmetry of the cylindrical well. In one embodiment, the length of the contact pin of the plug is greater than the distance between the contact hole (121) and the top of the ground terminal (112). Thus, the plug can rotate in the well (130) without interference from the ground terminal (112). Alternative embodiments are also disclosed in which the ground terminal for the polarized receptacle is a ground pin.

Description

Socket with improved structure

Technical Field

The present invention relates to a connector (contact) for connection to an electrical supply network, in particular a socket for facilitating the entry of a plug.

Background

Movable electrical equipment typically has a power cord with a plug and is connected to the power supply network by plugging the plug into a socket that is always connected to the power supply network. Currently, about 20 such connections are used in different countries. Collectively, the terminals having an electrically charged voltage are accessible through the contact holes of the socket, and the plug has protruding contact pins adapted to fit into the contact holes. The contact pins and the contact holes corresponding thereto have different shapes. For example, the united states uses plate-shaped contact pins, while europe has a common occurrence of cylindrical contact pins. Some connectors are polarized connectors, i.e. a specific contact pin should be connected to a specific conductive line indicating line (L) and zero (N). The other connector is an unpolarized connector (unpolarized) in which it is not important which contact pin is connected to the conductive line L or N. Both the polarized and non-polarized splices may be grounded (grounded) or ungrounded (ungrounded). This document relates to an earth socket having a terminal connected to electrical ground (earth) in addition to a conductive terminal having contact pins for a plug. Since the ground terminal is at a fixed ground potential and therefore does not transfer power during normal operation, the ground terminal may be exposed in the receptacle. The ground terminals are also of different design in different countries. For example, in germany and other european countries it is common to adapt the spring biased grounding clip to the slot of the plug, while france is common to adapt the grounding pin to the hole of the plug.

To facilitate the sale of electrical devices, and to facilitate travel with electrical devices from one country to another, electrical equipment (including plugs and sockets) is becoming more and more standardized. The U.S. International Trade Administration (ITA) has agreed on the letters a-N for the most common connections, while the european standard Certification for Electrical Equipment (CEE) is applicable to most electrical equipment in europe. For example, with the exception of the uk and ireland, most electrical devices in europe deliver earth plugs of the CEE7/7 type, which are included in class F of ITA. Such a plug is used hereinafter by way of example. Other types of linkers may be adapted by those skilled in the art without inventive effort. Other joint types will also be described in the relevant cases.

It is impractical to change the plugs on lights, ovens and other electrician equipment to adapt the equipment to the present invention. Since european electrical equipment currently delivers plugs of the CEE7/7 type and compatible types, one object of the present invention is to enable a european appliance to be able to receive a plug that can be received by a receptacle of the CEE7/7 type, but not necessarily all plugs that can be received by a receptacle of the CEE7/7 type. In summary, it is an object that the socket according to the invention should be able to receive plug types delivered by equipment sold for domestic use and also for use in countries of different standards (e.g. the uk and the us, such as 110V or 220-.

US 1812343a discloses a socket having short and long guide slots which guide contact pins on a plug towards corresponding openings on the socket when the plug is pressed against the short and long guide slots. At the same time, this causes the plug to rotate relative to the receptacle.

DE 653597C discloses a similar socket having two opposite semi-circular concave surfaces which are inclined in opposite directions towards the respective contact holes, so that when a plug is pressed against the socket the contact pins slide towards the contact holes and the plug rotates accordingly.

Some countries (e.g. danish, finland, norway and sweden) require sockets with child-safety means, i.e. devices that prevent children from touching the power supply network. Such child-resistant devices are usually caps covering the contact holes and/or devices requiring that the contact pins can only be inserted when they are pressed against all contact holes simultaneously.

In addition, there is an increasing interest in so-called universal designs, i.e. buildings, apartments, offices and articles of everyday use which are designed to enable handicapped persons to use them without help or additional adaptation. It is therefore another object of the present invention to provide a socket for such a universal design.

The existing power sockets (outlets) can be mounted completely on the outside of the wall or can be permanently connected to the power supply network in a box embedded in the wall, with a cover only on the outside of the wall. In both cases, there is a need to be able to retrofit existing installations of sockets.

It is therefore an object of the present invention to provide a socket that meets at least one of the above-mentioned needs and which offers advantages over the prior art.

Disclosure of Invention

The object of the invention is to obtain a socket according to claim 1.

In particular, the invention provides a socket comprising a cover having a cylindrical well with a diameter larger than the diameter of the surrounding cylinder surrounding the existing predetermined plug and at least two contact holes adapted to receive contact pins for transmitting electrical power, wherein each contact hole is positioned at the bottom of a recessed contact pin guide. The receptacle has a ground terminal disposed in the well.

When a plug is inserted into the well, the contact pins on the plug slide along the recessed guides toward the contact holes. Thus, the plug rotates about the axis of rotational symmetry of the cylindrical well.

In one embodiment, the length of the contact pin of the plug is greater than the distance between the contact hole and the top of the ground terminal. Thus, the plug may be rotated in the well without interference from the ground terminal.

The contact pin-guides preferably have a slant from their respective contact holes to narrower and shallower portions of the contact pin-guides. The contact pin-guide will thus have, viewed from above, an upwardly large opening surface close to the contact hole and a decreasing opening surface in the direction of rotation away from the contact hole. If the contact pins on the plug engage the narrower portions of the contact pin guides, the plug will be rotated in a particular direction (e.g., counterclockwise) toward the contact holes.

In some embodiments, the cover is connected to the contact box by a snap lock. This facilitates the mounting of the cover once the contact box is mounted on a wall or the like.

In some embodiments, the well further comprises two projections having flat side surfaces parallel to each other along the length of the well, the well further comprising a guide slot extending radially outward from a middle of the flat side surfaces and extending from a bottom of the well to a top surface of the projections. The side faces are adapted to the plug (for example a plug according to CEE 7/7) and the guide groove is in this case adapted to the guide rib on the plug. The sides and guide slots bear (take up) the load applied to the plug when the plug is inserted into the receptacle, and can also provide friction to retain the plug in the well.

In a first embodiment of the projections, both top faces of each projection are positioned perpendicular to the axis of rotational symmetry of the well. In this embodiment, the side surfaces and the guide grooves have only the functions described above.

In a second embodiment of the projections, the first top surface of each projection is positioned perpendicular to the axis of rotational symmetry of the well, and the second top surface of each projection forms a helicoid along the cylindrical wall of the well and has a minimum distance to the bottom of the well at the guide slot. In this embodiment, the first top surface prevents the plug from continuing to move axially in the well when the plug is incorrectly positioned in the well. Therefore, the present embodiment can be adapted to polarized contact. When the plug is correctly positioned in the well, the plug will slide along the helical top surface and thus move axially until the contact pin is inserted into the contact hole.

The helicoid preferably has the same inclination as the bottom of the contact pin-guide. Thus, the top surface supports the side portions of the plug (e.g., the guide ribs described above) while the contact pin-guides slide along the contact pin-guides toward the contact holes.

In a third embodiment of the protruding elements, both top surfaces of each protruding element are helicoids directed towards the guide slot. This facilitates the insertion of a plug having guide ribs or similar structures.

The socket preferably also has a guide extending from an outer surface of the cover towards the well. The guide guides the plug towards the well when moving against the outer surface of the cover.

Further features and advantages of the invention appear from the dependent claims and the following detailed description.

Drawings

The invention will be described in more detail hereinafter in the form of exemplary embodiments with reference to the accompanying drawings, in which:

fig. 1 is a perspective view of a socket as viewed from a first viewpoint;

fig. 2 is a perspective view of the socket of fig. 1 from a second viewpoint;

FIG. 3 is a side view of the receptacle of FIGS. 1 and 2 and having a plug partially inserted;

FIG. 4 is a cross-sectional view taken along the plane IV-IV in FIG. 3;

figure 5 is a top plan view of a connection box for the socket of figures 1 to 4;

FIG. 6 is a top view of the junction box of FIG. 5 with a cover;

FIG. 7 is a side view of the receptacle as viewed from the side of FIG. 3 oriented 90 laterally;

FIG. 8 shows a portion of an alternative embodiment viewed from above;

FIG. 9 is a cross-sectional view taken along plane IX-IX in FIG. 8;

FIG. 10 is a cross-sectional view taken along the plane X-X in FIG. 8;

FIG. 11 shows a guide with two parallel top surfaces;

FIG. 12 shows a guide with two sloped top surfaces;

FIG. 13 is a perspective view of a receptacle with ground clips; and

fig. 13 is a perspective view of a receptacle with ground pins.

Detailed Description

The figures are schematic and do not require measurement. Some details which are well known to a person skilled in the art have been left out for the sake of clarity. In fig. 1 to 7, a so-called "euro" (schuko) ground clip is used as a first example of the ground terminal 112, and the ground pin 150 is used as an example in fig. 8 to 12. The term ground terminal in the claims includes these and other elements used to connect a plug to ground. Further, the terms ground clip and ground pin in the following description should be understood as examples of the term "ground terminal" used in the claims.

Fig. 1 and 2 are perspective views of the socket 100, the socket 100 having a ground terminal 112, a cover 120, and a guide 123 that guides from an outer surface of the cover 120 toward a well (well)130 for receiving a plug 300. Fig. 1 also shows a junction box 110 filled in a standard well box. The cover has an integral and resilient snap lock 116, the snap lock 116 retaining the cover to the connection box 110. The connection box 110 has one or more openings (not shown) for ground cables (ground cables) from the power supply network. Trough-shaped contact pin guides 141,142 are fixedly disposed at the bottom of the well 130 and are best shown in fig. 2. The contact holes 121 for the contact pins on the plug 200 are positioned at the bottom of the groove-shaped contact pin guides 141, 142. When a plug is inserted into the well 130, the contact pins will slide along the guiding

surfaces

141 and 142 and descend along the imaginary helical surface to the respective contact hole 121. In other words, the contact pin-guides 141,142 have an inclined structure (entrainment) from their respective contact holes 121 to the narrower and shallower portions (i.e. clockwise in fig. 2) of the contact pin-

guides

141, 142.

Fig. 3 shows the plug 20 inserted into the receptacle 100 of the present invention. In this example, plug 200 is of the CEE7/7 type and receptacle 100 is of a compatible type for that plug. Line IV-IV shows an imaginary plane through the centers of the contact pins located on such a plug 200 and also through the centers of the contact holes 121 in the socket 100.

The receptacle 200 has a cylindrical surface 230 with a diameter slightly smaller than the well 130 shown in the previous figures. Cylindrical surface 230 is interrupted by a plane 231 parallel to the plane of the paper at the position shown. The guide ribs 232 project from the plane 231 and are surrounded by an imaginary extension of the cylindrical surface 230, so that the guide ribs 232 can penetrate down into the cylindrical well 130 shown in fig. 1 and 2. A similar flat surface 231 having guide ribs 232 is provided on a radially opposite side of the plug 200.

As described in connection with fig. 1, the cover 210 is connected to the connection box 110 by the latch 116. Here, the catch 116 is an integral and resilient part of the cover. When the cover is mounted to the connection box 110, the catch 116 slides along the walls of the connection box. When the cover is installed, the latches 116 are biased inwardly toward the connection box 110 so that a shoulder or similar portion abuts an edge of the connection box 110 to retain the cover on the connection box 110. Alternatively, the cover may be attached to the junction box 110 by one or more bolts in a known manner.

Fig. 4 is a sectional view taken along the plane IV-IV in fig. 3. The plug 200 is not part of the present invention and therefore its internal details are not illustrated. Upon insertion of plug 200, guide 123, which is located between the outer surface of cover 120 and well 130 (fig. 1), guides the plug toward well 130. In fig. 4, the guide 123 is shown as a concave rounded transition, while in fig. 9-11 it is shown as a frustoconical transition. It should be understood that any shape capable of guiding plug 200 toward well 130 may be used. In the position shown in fig. 4, the contact pins 221 of the plug are barely inserted into the contact holes 121, and the bottom of the plug 200 (from which the contact pins 221 extend) is positioned within the guides 123, but above the ground clip 112. It will be appreciated that the distance between the contact pin guides 141,142 and the ground clip 112 must be less than the length of the contact pin 121. In the CEE7/7 plug, the contact pins 221 have a length of 19 mm. Thus, in the example of fig. 4, the top of the ground clip 112 is higher than the bottom of the contact pin guides 141,142, e.g., 16-18mm, so that the plug 200 can be rotated without being obstructed or disturbed by the ground clip 112. Similarly, the distance from the contact hole 121 to other types of ground contacts (e.g., the ground pin (150 in fig. 8-10) of a french receptacle) is less than the length of the ground pin 221.

Fig. 4 also shows that the lower edge of the catch 116 engages with the edge of the connection box 110 and thus holds the cover.

Fig. 5 is a top view of the connection box 110, more specifically, the receptacle without the cover, as viewed from above in the previous figures. The connection box 110 comprises a plate 1100, the plate 1100 having fastening holes 1101 for attachment to a wall or the like, for example by bolts. A ground potential (electrical ground potential) is provided to a complementary ground rail (not shown in fig. 5) on the receptacle through two diametrically opposed ground clips 112. To this end, the ground clips 112 are biased radially inward and slide along the axially oriented ground rails when the plug is inserted or removed.

The ground terminal 1120 is connected to the ground of the power supply network. The ground terminal 1120 may be a ground rail fixedly connected to the ground clip 112, in which case the ground clip 112 is connected to the connection box 110. Alternatively, the ground clip 112 may be connected to a ground rail on the cover (not shown in fig. 5) that engages the ground terminal when the cover is installed.

In use, the sliding terminals 111 (fig. 6) located in the contact holes 121 are electrically connected to live connectors of the power supply network and provide mechanical and electrical connection to the contact pins (221, fig. 4) on the plug.

Fig. 6 shows the receptacle 100 of the same size and orientation as the connection box 110 of fig. 5. Thus, the cover 120 is mounted on the connection box 110 of fig. 5. The lid includes a top plate 120, and the top plate 120 need not be flat. The ground clips 112 are positioned in openings on the cover 120, and the axis between the ground clips 112 is perpendicular to the axis passing through the center of the contact hole 121.

Fig. 7 shows the receptacle as viewed from a side perpendicular to the side shown in fig. 3. In the illustrated embodiment, the ground clip 112 is positioned in the opening 114 through a wall of the cover 120. Thus, during insertion of the plug, the ground clip 112 can be partially squeezed outward and pushed into the opening 114. When the plug is inserted, the bias will force the ground clip 112 against a complementary ground rail (212, fig. 10) located on the plug.

In the embodiment shown in fig. 1 to 7, it is not important which contact pin on the plug is inserted into which contact hole 121 of the socket, and a connection of the original german "euro" type with two symmetrically arranged ground clamps 112 is used as an example. In the example of fig. 8-10, the symmetrical ground clip 112 is replaced by an asymmetrically arranged ground pin 150 to show a polarized socket (polared socket), i.e. each contact pin must be inserted into a specific contact hole. The CEE7/7 type plug has a hole that receives a grounding pin 150 of the original french standard and is therefore used as an example.

Fig. 8 shows an alternative embodiment from above. As described in connection with fig. 3, the plug 200 may have a substantially cylindrical outer surface 230 cut by two flats 231, each flat 231 having a protruding guide rib 232. The embodiment of fig. 8 to 10 has a similar substantially cylindrical well 130, the well 130 having protrusions 131 and guide slots 132 adapted for CEE7/7 type, compatible type plugs. The guide slots 132 extend radially outward from the side of the parallel plane toward the cylindrical wall of the well 130, i.e., along an axis passing through the center of the contact hole 121 in the

contact pin guide

141, 142. The plane IX-IX is perpendicular to this axis and is cut through the center of the contact pin 150 in fig. 8. The guide slots 132 extend from the bottom of the well 130 to the top surfaces 1210 and 1311. Top surfaces 1310 are diametrically opposed to each other and top surfaces 1311 are diametrically opposed to each other.

A variant of a german ground clip (e.g. as shown in fig. 6) may also advantageously be provided by similar protruding or guiding surfaces 131 and guiding grooves 132. An "alternative embodiment" is to be understood here and hereinafter as a joint (contact) with

guide surfaces

131, 132 etc. in the well, whether the ground comprises a wire clamp as in fig. 6 or a pin as in fig. 8.

Fig. 9 is a sectional view along plane IX-IX in fig. 8 and shows a first embodiment of the protruding member 131. The embodiment of the guide 123 and the contact pin guides 141,142 as shown in fig. 1 to 7 will not be described here. Here, the portion 1310 of the top surface for the piece 131 extends perpendicular to the rotational symmetry axis of the well and is disposed at a sufficient distance from the bottom of the well 130 to allow the plug 200 to rotate over the grounding pin 150 as the guide ribs 232 (fig. 3 and 10) of the plug slide along the top surface portion 1310.

A further portion 1311 of the top surface of the piece 131 slopes downwards towards the guide groove 132. When the inclined surface 1311 extends along the cylindrical wall, the top surface 1311 in this embodiment is a spiral surface inclined in the same direction as the direction in which the socket will be guided toward the contact hole 121 during insertion of the socket (i.e., counterclockwise in fig. 8 and toward the left-hand side of fig. 9). Thus, the plug of fig. 3 may move axially downward onto the grounding pin 150 when the guide ribs 232 on the plug slide along the portion 1311 of the top surface, rather than when the guide ribs 232 slide along the portion 1310 of the top surface.

Fig. 10 shows the engagement of the contact pins 221 of the socket 200 with the bottoms of the contact pin guides 141, 142. The guide ribs 232 are supported by the two top surfaces 130, the two top surfaces 130 being radially symmetrically arranged with respect to each other, see fig. 8. Thus, the axis of rotation of the plug 200 is parallel to the axis of the grounding pin 150. When the plug 200 is rotated such that the guide ribs slide along the helicoids 1311, the axis of rotation remains parallel to the pins 150, and if the plug is correctly positioned in the well, the pins 150 will easily slide into the corresponding holes on the plug. That is, the axis of the grounding hole on the plug 200 is less likely to tilt relative to the grounding pin 150. If the pin 150 does not enter the hole, the plug must be mis-positioned 180 ° so that the N pins are aligned with the L holes, and vice versa. The top surface 1310 and the contact pin guides 141,142 in fig. 9 support a further rotation of 180 °.

Without the protrusions 131, the symmetrical shape of the contact pin guides 141,142 allows the plug 200 to be guided axially down to the contact hole 121 wherever the contact pins engage. With the embodiment of fig. 9, the guide ribs 232 may engage the top surface 1310, and the contact pins 221 may not engage the bottom of the contact pin guides 141, 142. If the contact pin 221 is rotated towards the narrower and shallower parts of the contact pin guides 141,142, the contact pin 221 will quickly reach the position shown in fig. 10. Continued rotation in the same direction (i.e., clockwise in fig. 8) will cause the plug 200 to lift axially upward in the well 130. A slight rotation in the opposite direction will move the guiding ribs above the top surface 1311, where the top surface 1311 is helical, so that the contact pins 221 are guided axially downwards towards the contact holes 121. Therefore, even with the horizontal guide surface 130, the user can quickly receive a tactile feedback (tactilefeedback) of the correct rotational direction, more precisely, with the top surface 1310, which is perpendicular to the rotational symmetry axis of the well at a distance from the contact hole 121 that is greater than the length of the contact pin 221 of the plug. Thus, the variant of fig. 9 and 10 is advantageous for polarized contacts, here exemplified by the eccentric pin 150, because the guide is asymmetrical.

Fig. 11 shows a second embodiment of

top surfaces

1310 and 1311, where the two pairs of

top surfaces

1310,1311 extend perpendicular to the axis of rotational symmetry of the well (i.e. parallel to the plane of the paper in fig. 8). In this embodiment, the height from the contact hole 121 to the

top surface

1310,1311 of the protruding piece 131 is preferably adapted such that the contact pin 221 of the plug can slide along the bottom of the contact pin guide 141,142 without interference during insertion of the plug. The grooves 132 then receive the guide ribs 232 on the plug when the plug is fully inserted into the receptacle and provide a frictional force to retain the plug and also retain the plug by receiving a force applied to the plug when the plug is inserted into the receptacle 100.

Fig. 12 shows a third embodiment of the protruding member 131, wherein both

top surfaces

1310 and 1311 are inclined downwards towards the guiding groove 132. This embodiment facilitates the insertion of the guide rib 232 into the guide groove 132. As with the embodiment of fig. 9 and 10, support from the top surface aligns the ground pin 150 with the plug aperture. The embodiment of fig. 12 does not support the 180 ° rotation of the embodiment of fig. 9 and 10. As with the embodiment shown in fig. 9-11, the embodiment of fig. 12 provides friction and supports against lateral forces on the top of the plug 200 when the plug 200 is fully inserted into a receptacle.

In all three embodiments shown in fig. 9-12, grounding pin 150 is long enough to ensure that plug 200 is grounded before contact pin 221 engages a live terminal (live terminal). This is a common requirement for standards for sockets with ground terminals, including CEE 7/7. Provided that this requirement is met, the length of the contact pins 150 may be adapted to the length of the guides in the socket 100, the contact pins 221 on the plug 200 and the distance from the

top surfaces

1310,1311 to the live terminals (not shown) of the socket 100. In a preferred embodiment, the inclined surface 1311 has the same inclination as the bottom surfaces of the contact pin guides 141 and 142.

As can be appreciated from the description of fig. 8-12,

top surfaces

1310 and 1311 and ground pin 150 provide tactile feedback to the user of the orientation of the plug, and the asymmetric shape of fig. 9 (particularly horizontal surface 1310) is particularly advantageous for changing the positioning of the plug in well 130.

Fig. 13 shows the receptacle 100 with the guide surfaces 1310 and 1311 described in connection with fig. 8-12, but with the ground clip 112 in place of the ground pin 150. The top plate 120 with the transition 123 and the slot-shaped

symmetrical guides

141 and 142 are as described above. Fig. 14 is similar to fig. 13, but with a ground pin 150 instead of the ground clip 112. The embodiments of fig. 13 and 14 can both be used for plugs according to european standard CEE7/7 and represent non-polarized and polarized connectors, respectively. Additionally, it should be understood that the present invention is not limited to CEE7/7 and that symmetrical or asymmetrical guides similar to

top surfaces

1310 and 1311 in fig. 9, 11, and 12 may be used with other types of joints.

The present invention has been illustrated with reference to a socket for a particular type of plug but the scope of the invention is defined by the claims.

Claims

1. A socket (100), the socket (100) comprising a cover (120) and at least two contact holes (121), the cover (120) having a cylindrical well (130), the diameter of the well (130) being larger than the diameter of a surrounding cylinder (230) surrounding an existing predetermined plug (200), the at least two contact holes (121) being adapted to receive contact pins (211) for transmitting power, wherein a ground terminal (112; 150) is provided in the well (130), the well (130) further comprising two protrusions (131), the two protrusions (131) having flat side faces parallel to each other in a length direction of the well, the well (130) further comprising guide slots (132), the guide slots (132) extending radially outward from a middle of the flat side faces and from a bottom of the well (130) to a top face (1310,1311) of the protrusions (131), it is characterized in that the preparation method is characterized in that,

each contact hole (121) being positioned at the bottom of a recessed contact pin-guide (141,142), and the contact pin-guides (141,142) having an inclination from the respective contact hole (121) to a narrower and shallower portion of the contact pin-guide (141,142) that is distant from the contact hole (121) in the rotational direction, the contact hole (121) being located at a large opening surface as viewed from above,

wherein the first top surface (1310) of each protrusion (131) is positioned perpendicular to the rotational symmetry axis of the well and the second top surface (1311) of each protrusion (131) forms a helicoid along the cylindrical wall of the well and has a minimum distance to the bottom of the well (130) at the guiding slot (132).

2. The socket (100) of claim 1, wherein the length of the contact pin (221) of the plug is greater than the distance between the contact hole (121) and the top of the ground terminal (112,150).

3. The socket (100) of claim 1, wherein the cover (120) is connected to the contact box (110) by a snap lock (116).

4. The socket (100) according to claim 1, wherein the helicoid (1311) has the same inclination as the bottom of the contact pin guides (141, 142).

5. The socket (100) according to any one of claims 1-4, wherein the socket (100) further comprises a guide (123) extending from an outer surface of the cover (120) towards the well (130).