CN215527992U

CN215527992U - Movable multi-position socket

Info

Publication number: CN215527992U
Application number: CN202121743754.8U
Authority: CN
Inventors: 沈志富; 姚志国
Original assignee: Nanjing Putian Hongyan Electrical Appliance Technology Co ltd
Current assignee: Nanjing Putian Hongyan Electrical Appliance Technology Co ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2022-01-14
Anticipated expiration: 2031-07-29

Abstract

The utility model discloses a movable multi-position socket, and belongs to the technical field of sockets. The portable many sockets include insulating casing, set up row that inserts the unit and binding post in insulating casing's installation intracavity, it inserts the subassembly and one three hole row of subassembly to insert the unit including the two hole row of tribasic that are connected each other electricity and insert the subassembly with one three hole row, three hole row insert the subassembly and form five hole row insert the subassembly with two adjacent holes row, two hole row insert the subassembly and include a pair of one-way two poles of the earth plug bushes of a pair of second, the earth plug bush sets up between rather than adjacent a pair of one-way two poles of the earth plug bushes, two holes row insert the subassembly and set up with two sets of two hole sockets one-to-ones, five hole row insert the subassembly and correspond the setting with five hole sockets. The movable multi-position socket disclosed by the utility model can be suitable for different types of plugs and can meet the power consumption requirements of more multimedia equipment.

Description

Movable multi-position socket

Technical Field

The utility model relates to the technical field of sockets, in particular to a movable multi-position socket.

Background

The existing movable socket for the optical fiber box has the advantages that the number of the socket is only two and five-hole socket output, more multimedia equipment power consumption requirements cannot be met, and different types of multimedia plug forms cannot be met.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a movable multi-position socket which can be suitable for different types of plugs and can meet more power consumption requirements of multimedia equipment.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a mobile multi-site outlet comprising:

the insulating shell is provided with a mounting cavity, and the insulating shell is provided with two groups of two-hole sockets and one group of five-hole sockets which are communicated with the mounting cavity;

the three-hole extension socket assembly and the adjacent two-hole extension socket assembly form a five-hole extension socket assembly, the two-hole extension socket assembly comprises a pair of first one-way two-pole plug bushes, the three-hole extension socket assembly comprises a pair of second one-way two-pole plug bushes and a grounding plug bush, the grounding plug bush is arranged between the pair of first one-way two-pole plug bushes adjacent to the grounding plug bush, the two-hole extension socket assemblies and the two groups of two-hole sockets are arranged in a one-to-one correspondence mode, and the five-hole extension socket assembly and the five-hole socket assembly are arranged in a corresponding mode;

binding post, set up in the installation intracavity, binding post with arrange the unit electricity and connect, just binding post can be connected with external power source electricity.

Optionally, two sets of the two-hole sockets and one set of the five-hole socket are arranged along the length direction of the insulating housing and are both arranged on the same side of the insulating housing.

Optionally, the three-position two-hole extension socket assembly is arranged on the same side of the three-hole extension socket assembly along the length direction of the insulating shell.

Optionally, the extension socket unit comprises an L-pole copper bar, an N-pole copper bar and an E-pole copper bar which are arranged in parallel at intervals, the grounding plug bush is arranged on the E-pole copper bar, and the E-pole copper bar is arranged between the L-pole copper bar and the N-pole copper bar;

the L-pole copper bar is provided with three first plug bushes, the N-pole copper bar is provided with three second plug bushes, the first plug bushes and the corresponding second plug bushes form a pair of first one-way two-pole plug bushes, and the grounding plug bushes are arranged between the first plug bushes and the second plug bushes adjacent to the first plug bushes;

still be provided with a third plug bush on the L utmost point copper bar, still be provided with a fourth plug bush on the N utmost point copper bar, the third plug bush with the fourth plug bush forms a pair of the one-way two poles of earth plug bush of second.

Optionally, the insulating housing comprises:

a first housing;

the second shell and the first shell form a first installation cavity, the extension socket unit is arranged in the first installation cavity, and the two-hole socket and the five-hole socket are arranged on one side, away from the first shell, of the second shell;

and the third shell and the second shell are arranged on the same side of the first shell, a second installation cavity is formed by the third shell and the first shell, and the wiring terminal is arranged in the second installation cavity.

Optionally, one end of the second housing extends to form a connecting portion, the connecting terminal is connected to the connecting portion through a fastener, and the connecting portion is disposed in the second mounting cavity.

Optionally, a wire pressing groove is formed between the third housing and the first housing, the wire pressing groove is disposed in the second mounting cavity, and an external power line is inserted through the wire pressing groove.

Optionally, the second housing is detachably connected to the first housing, and the third housing is detachably connected to the first housing.

Optionally, the first housing is provided with a mounting hole, and the first housing is connected with an external structure through the mounting hole by using a fastener.

Optionally, a first protection door assembly is arranged between the two-hole socket and the two-hole socket assembly, and a second protection door assembly is arranged between the five-hole socket and the five-hole socket assembly.

The utility model has the beneficial effects that:

when the movable multi-position socket is used, the power distribution unit is electrically connected with an external power supply through the wiring terminal, the two-end plug is plugged in the two-hole power distribution assembly through the two-hole jack so as to be electrically connected with the external power supply, and when the five-hole jack is used, the movable multi-position socket can be independently used for the two-end plug or the three-end plug, so that the two-end plug is plugged in the two-hole power distribution assembly or the three-end plug is plugged in the three-hole power distribution assembly so as to be electrically connected with the external power supply, and therefore the movable multi-position socket can be suitable for plugs with different types, namely two-end plugs and three-end plugs, can meet more power utilization requirements of multimedia equipment, and is more suitable for being used in an optical fiber box. Because the grounding plug bush is arranged between a pair of first one-way two-pole plug bushes adjacent to the grounding plug bush, the space between the three-hole extension socket assembly and the two-hole extension socket assembly adjacent to the three-hole extension socket assembly is shortened, so that the space occupied by the installation cavity is reduced, the size of the insulating shell can be reduced, the size of the movable multi-position socket is reduced, the size is small, and the space occupied in the multimedia box is saved.

Drawings

FIG. 1 is a schematic structural diagram of a mobile multi-position socket according to an embodiment of the present invention;

fig. 2 is an exploded view of a mobile multi-outlet provided by an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a third housing according to an embodiment of the present invention.

In the figure:

11. a first housing; 111. a support portion; 112. a first mounting groove; 113. a first mounting hole; 114. a second mounting hole; 115. a support pillar; 116. mounting a column; 117. connecting columns; 12. a second housing; 121. two-hole sockets; 122. a five-hole socket; 123. a connecting portion; 13. a third housing; 131. a second mounting groove;

21. an L-pole copper bar; 211. a first sleeve; 212. a third plug bush; 22. an N-pole copper bar; 221. a second sleeve; 222. a fourth sleeve; 23. e pole copper bar; 231. a grounding plug bush;

3. a wiring terminal;

41. a first protective door assembly; 42. a second protective door assembly;

5. and (4) screws.

Detailed Description

In order to make the technical problems solved, technical solutions adopted and technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The embodiment provides a movable multi-position socket which comprises an insulating shell, a power strip unit and a wiring terminal 3; specifically, the insulating shell is provided with a mounting cavity, and the insulating shell is provided with two groups of two-hole sockets 121 and a group of five-hole sockets 122 which are communicated with the mounting cavity; the socket assembly comprises a three-position two-hole socket assembly and a one-position three-hole socket assembly, the three-hole socket assembly and the two-hole socket assembly adjacent to the three-hole socket assembly form a five-hole socket assembly, the two-hole socket assembly comprises a pair of first one-way two-pole plug bushes, the three-hole socket assembly comprises a pair of second one-way two-pole plug bushes and a grounding plug bush 231, the grounding plug bush 231 is arranged between the pair of first one-way two-pole plug bushes adjacent to the grounding plug bush 231, the two-position two-hole socket assembly and two groups of two-hole sockets 121 are arranged in a one-to-one correspondence manner, and the five-hole socket assembly and the five-hole socket 122 are arranged in a corresponding manner; binding post 3 sets up in the installation intracavity, and binding post 3 is connected with row and inserts the unit electricity, and binding post 3 can be connected with external power source electricity.

During the use, arrange and insert the unit and be connected with external power supply electricity through binding post 3, thereby the double-end plug is pegged graft in the double-hole row's of inserting subassembly through two hole sockets 121 and is realized being connected with external power supply electricity, when five hole sockets use, can be used for double-end plug or triple plugs alone, thereby make double-end plug peg graft on the double-hole row's of inserting subassembly or make triple plugs peg graft on three holes row's of inserting subassembly and realize being connected with external power supply electricity, thereby make portable many sockets can be applicable to the plug of two and three different grade types, can satisfy more multimedia device power consumption demands, more be fit for the fiber box and use. Because the grounding plug bush 231 is arranged between the pair of first one-way two-pole plug bushes adjacent to the grounding plug bush, the distance between the three-hole extension socket assembly and the two-hole extension socket assembly adjacent to the three-hole extension socket assembly is shortened, so that the space occupied by the installation cavity is reduced, the size of the insulating shell can be reduced, the size of the movable multi-position socket is reduced, the size is small, and the space occupied in the multimedia box is saved.

Optionally, two sets of two-hole sockets 121 and one set of five-hole sockets 122 are arranged along the length direction of the insulating housing, so that the width of the mobile multi-position socket is reduced to adapt to the use space; a plurality of two-hole sockets 121 and a plurality of five-hole sockets 122 are all arranged on the same side of the mobile multi-position socket, so that plugs of different devices are plugged towards the same side, different plugs are prevented from being plugged around the mobile multi-position socket, and the space in the multimedia box is saved.

Optionally, the three-position two-hole extension socket assembly is arranged on the same side of the three-hole extension socket assembly along the length direction of the insulating shell; when the three-head plug is plugged in the five-hole jack 122, the space occupied by other two-hole jacks 121 is prevented, the use of other two-head plugs is influenced, and the layout is more reasonable.

Further optionally, as shown in fig. 2, the extension socket unit includes an L-pole copper bar 21, an N-pole copper bar 22, and an E-pole copper bar 23 that are arranged in parallel and at an interval, the grounding plug bush 231 is arranged on the E-pole copper bar 23, and the E-pole copper bar 23 is arranged between the L-pole copper bar 21 and the N-pole copper bar 22; three first plug bushes 211 are arranged on the L-pole copper bar 21, three second plug bushes 221 are arranged on the N-pole copper bar 22, a pair of first one-way two-pole plug bushes are formed by the first plug bushes 211 and the corresponding second plug bushes 221, and the grounding plug bush 231 is arranged between the first plug bush 211 and the second plug bush 221 adjacent to the first plug bush; the L-pole copper bar 21 is further provided with a third plug bush 212, the N-pole copper bar 22 is further provided with a fourth plug bush 222, and the third plug bush 212 and the fourth plug bush 222 form a pair of second unidirectional two-pole plug bushes. The three first plug bushes 211 and the third plug bush 212 are integrally arranged with the L-pole copper bar 21, the three second plug bushes 221 and the fourth plug bush 222 are integrally arranged with the N-pole copper bar 22, and the grounding plug bush 231 is integrally arranged with the E-pole copper bar 23, so that the structure is simple, welding spots are reduced, the electric conductivity is excellent, the product stability is improved after long-term use, and the power supply safety is ensured; specifically, the L pole copper bar 21, the N pole copper bar 22, and the E pole copper bar 23 are all formed by press.

In this embodiment, the insulating housing includes a first housing 11, a second housing 12 and a third housing 13, where the second housing 12 and the first housing 11 form a first mounting cavity, a patch board unit is disposed in the first mounting cavity, and the two-hole jack 121 and the five-hole jack 122 are both disposed on a side of the second housing 12 away from the first housing 11, and during normal use, a plug is directly plugged into the two-hole jack 121 or the five-hole jack 122, and for safety, the first housing 11 and the second housing 12 do not need to be detached; the third shell 13 and the first shell 11 form a second installation cavity, a wiring terminal 3 is arranged in the second installation cavity, before the use, the wiring terminal 3 needs to be connected with an external power line, and at the moment, the first shell 11 and the third shell 13 need to be opened; therefore, the first installation cavity and the second installation cavity are respectively arranged, and the use convenience and the use safety can be improved. Preferably, the third housing 13 and the second housing 12 are disposed on the same side of the first housing 11, that is, the two-hole socket 121 and the five-hole socket 122 for plugging and connecting are disposed on the same side of the terminal 3 for connecting an external power line, when the mobile multi-position socket is fixed in the multimedia box, the external power line can be connected by directly detaching the third housing 13, which facilitates the internal connection of the external power line in the multimedia box.

Specifically, first housing 11 is provided with a first receiving groove, second housing 12 is provided with a second receiving groove, and third housing 13 is provided with a third receiving groove, and first receiving groove and second receiving groove form a first mounting cavity, and first receiving groove and third receiving groove form a second mounting cavity.

Preferably, the third housing 13 is detachably connected to the first housing 11, so that the third housing 13 can be conveniently detached; in this embodiment, the third housing 13 is connected to the first housing 11 by screws, so as to be easily disassembled and assembled, and the mounting structure is stable, thereby preventing the danger of electric shock due to easy opening. In this embodiment, a through hole is formed in the third housing 13, a connection post 117 is disposed in the first accommodating groove, a stud hole is formed in the connection post 117, and a screw passes through the through hole in the third housing 13 and the stud hole of the first connection post 117, so that the third housing 13 is connected to the first housing 11.

Preferably, the second housing 12 is detachably connected to the first housing 11; the second shell 12 is convenient to disassemble and assemble; in this embodiment, the second housing is connected to the first housing 11 through screws, so as to be convenient for disassembly and assembly, and the mounting structure is stable, thereby preventing the electric shock hazard caused by easy opening. In this embodiment, a through hole is formed in the second housing 12, the mounting post 116 is disposed in the first accommodating groove, a stud hole is formed in the mounting post 116, and the second housing 12 is connected to the first housing 11 by passing through the through hole in the second housing and the stud hole in the mounting post 116 through a screw.

Optionally, one end of the second housing 12 extends to form a connecting portion 123, and the terminal 3 is connected to the connecting portion 123 by a fastener, so that the terminal 3 is fixedly connected to the insulating housing; compared with the prior art, the wiring terminal needs to be installed on the plastic part firstly, and the plastic part is connected with the insulating housing, so that the wiring terminal is connected with the insulating housing, the wiring terminal 3 is directly fixed on the insulating housing, the plastic part does not need to be used, the structure is simplified, the installation is convenient, and the cost is reduced. And connecting portion 123 sets up in the second installation cavity, makes the structure compacter.

In this embodiment, the supporting portion 111 is disposed in the first accommodating groove, and when the connection terminal 3 is fixed to the connecting portion 123, the supporting portion 111 can be supported on the connection terminal 3, so that the connection terminal 3 can be more stably mounted. Specifically, the supporting portion 111 may be cylindrical, one end of the cylinder is disposed at the bottom of the first accommodating groove, and the other end of the cylinder is used for supporting the connecting terminal 3.

In this embodiment, a supporting pillar 115 is further disposed in the first accommodating groove, and the supporting pillar 115 is used for supporting the L-pole copper bar 21, the N-pole copper bar 22, and the E-pole copper bar 23, so that the structure is more stable.

The wire pressing plates on the existing socket are independently configured, so that the installation steps are multiple, the installation is neglected by a client, and potential safety hazards of use are brought to the socket; optionally, a wire pressing groove is formed between the third housing 13 and the first housing 11, the wire pressing groove is disposed in the second installation cavity, and the external power line penetrates through the wire pressing groove; because first shell 11 and third shell 13 need not the secondary installation from the structure of taking during wire pressing groove, connect the external power line after, be connected first shell 11 and third shell 13 and can realize the setting of external power line ball, saved the installation procedure, material saving and cost have improved the security.

In this embodiment, as shown in fig. 2 and fig. 3, a first mounting groove 112 is formed in the first housing 11, a second mounting groove 131 is formed in the third housing 13, the first mounting groove 112 and the second mounting groove 131 are oppositely disposed and form a wire pressing groove, after the external power line is connected, the external power line is inserted into the second mounting groove 131, then the third housing 13 is mounted, the second mounting groove 131 is pressed on the external power line, and the wire pressing groove for pressing the external power line is formed after the third housing 13 is fixed to the first housing 11.

As shown in fig. 2, a first protection door assembly 41 is arranged between the two-hole socket 121 and the two-hole extension socket assembly, and a second protection door assembly 42 is arranged between the five-hole socket 122 and the five-hole extension socket assembly, when two external plugs are inserted, the first protection door assembly 41 is opened, and the two plugs can be inserted into the two-hole extension socket assembly, specifically, the two plugs are inserted into the first plug bush 211 and the second plug bush 221, so that the two plugs are plugged into the mobile multi-position socket; when no external two-end plug is inserted, the first protection door assembly 41 is closed, the two-hole extension socket assembly and the two-hole sockets 121 can be isolated, an external structure is prevented from penetrating through the two-hole sockets 121 to contact the two-hole extension socket assembly, accidental electric shock is prevented, and the use safety is improved; similarly, second protection door subassembly 42 can be correspondingly opened when three plugs or two plugs are inserted, then second protection door subassembly 42 closes when not inserting, can keep apart five holes and arrange and insert subassembly and five hole sockets 122, has prevented that exterior structure from passing five hole sockets 122 contacts on five holes arrange and insert the subassembly, prevents that the accident from electrocuteeing and taking place, has improved safety in utilization. Specifically, the first protective door assembly 41 and the second protective door assembly 42 can refer to the prior art and are not described in detail. In this embodiment, the second housing 12 is provided with a mounting groove at a side facing the first housing 11, and the first protective door assembly 41 and the second protective door assembly 42 are provided in the mounting groove.

Optionally, as shown in fig. 1 and fig. 2, a mounting hole is formed in the first housing 11, and the first housing 11 is connected to an external structure through the mounting hole by using a fastener, so that the first housing 11 is conveniently dismounted from the external structure, and specifically, the movable multi-position socket is conveniently dismounted from the optical fiber box. In this embodiment, two ends of the first housing 11 along the length direction are provided with two mounting ears, one mounting ear is provided with a first mounting hole 113, and the other mounting ear is provided with a second mounting hole 114, so that the first housing 11 can be conveniently mounted on an external structure from the front; further specifically, first mounting hole 113 is the round hole, and second mounting hole 114 is rectangular hole, realizes through first mounting hole 113 that first shell 11 is fixed mutually with the position of exterior structure, can realize through second mounting hole 114 that first shell 11 is adjusted mutually with the position of exterior structure, further improves the suitability of portable many sockets.

In this embodiment, the mobile multi-jack socket includes two-hole sockets and one five-hole socket which are adjacently arranged; the pitch of the first mounting hole and the second mounting hole is 144 +/-0.5 mm, so that the length of the movable multi-position socket is in a low state. Meanwhile, the internal space of the box body for installation and the fact that a power supply (transformer) plug on the movable multi-position socket does not interfere with the door of the installed box body in normal use are considered, the width of the multi-position movable socket is not more than 50mm, and the thickness of the multi-position movable socket is not more than 30 mm.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A portable multi-position jack, comprising:

the insulating shell is provided with a mounting cavity, and the insulating shell is provided with two groups of two-hole sockets (121) and one group of five-hole sockets (122) which are communicated with the mounting cavity;

the socket comprises an installation cavity, a socket unit and a socket unit, wherein the installation cavity is internally provided with an installation cavity, the socket unit comprises a three-position two-hole socket assembly and a one-position three-hole socket assembly which are electrically connected with each other, the three-hole socket assembly and the adjacent two-hole socket assembly form a five-hole socket assembly, the two-hole socket assembly comprises a pair of first one-way two-pole plug bushes, the three-hole socket assembly comprises a pair of second one-way two-pole plug bushes and a grounding plug bush (231), the grounding plug bush (231) is arranged between the pair of first one-way two-pole plug bushes adjacent to the grounding plug bush, the two-hole socket assemblies and two groups of two-hole sockets (121) are arranged in a one-to-one correspondence manner, and the five-hole socket assembly and the five-hole socket (122) are arranged in a corresponding manner;

binding post (3), set up in the installation cavity, binding post (3) with arrange the unit electricity and connect, just binding post (3) can be connected with external power source electricity.

2. A mobile multi-outlet socket according to claim 1 wherein two sets of said two-hole sockets (121) and one set of said five-hole sockets (122) are disposed along the length of said housing and are disposed on the same side of the housing.

3. A multi-outlet mobile multi-outlet jack according to claim 2 wherein three positions of said two-outlet extension module are disposed on the same side of said three-outlet extension module along the length of said insulated housing.

4. A mobile multi-jack socket according to claim 3, wherein the extension socket unit comprises an L-pole copper bar (21), an N-pole copper bar (22) and an E-pole copper bar (23) which are arranged in parallel and spaced apart from each other, the grounding plug bush (231) is arranged on the E-pole copper bar (23), and the E-pole copper bar (23) is arranged between the L-pole copper bar (21) and the N-pole copper bar (22);

the L-pole copper bar (21) is provided with three first plug bushes (211), the N-pole copper bar (22) is provided with three second plug bushes (221), the first plug bushes (211) and the corresponding second plug bushes (221) form a pair of first one-way two-pole plug bushes, and the grounding plug bush (231) is arranged between the first plug bush (211) and the second plug bush (221) adjacent to the first plug bush;

still be provided with a third plug bush (212) on L utmost point copper bar (21), still be provided with a fourth plug bush (222) on N utmost point copper bar (22), third plug bush (212) with fourth plug bush (222) form a pair of the one-way two poles of earth plug bush of second.

5. A multi-outlet mobile multi-outlet according to any of claims 1 to 4, wherein said insulating housing comprises:

a first housing (11);

the second shell (12) and the first shell (11) form a first installation cavity, the extension socket unit is arranged in the first installation cavity, and the two-hole socket (121) and the five-hole socket (122) are both arranged on one side, away from the first shell (11), of the second shell (12);

the third shell (13) and the second shell (12) are arranged on the same side of the first shell (11), the third shell (13) and the first shell (11) form a second installation cavity, and the wiring terminal (3) is arranged in the second installation cavity.

6. A mobile multi-position socket according to claim 5, wherein a connecting portion (123) is extended from one end of the second housing (12), the connecting terminal (3) is connected to the connecting portion (123) by a fastener, and the connecting portion (123) is disposed in the second mounting cavity.

7. Mobile multiposition socket according to claim 5, characterized in that a wire compression groove is formed between the third housing (13) and the first housing (11), said wire compression groove being provided in the second mounting cavity, an external power line being passed through said wire compression groove.

8. Mobile multi-position socket according to claim 5, wherein said second housing (12) is detachably connected to said first housing (11) and said third housing (13) is detachably connected to said first housing (11).

9. A multi-outlet mobile multi-outlet according to claim 5, wherein said first housing (11) is provided with mounting holes, and said first housing (11) is connected to an external structure by means of fasteners through said mounting holes.

10. Mobile multiposition socket according to claim 5, characterized in that a first protective door assembly (41) is arranged between the two-hole socket (121) and the two-hole extension assembly, and a second protective door assembly (42) is arranged between the five-hole socket (122) and the five-hole extension assembly.