CN219717449U - Power supply rail, adapter and rail socket - Google Patents

Abstract

The disclosure provides a power supply rail, an adapter and a rail socket, and belongs to the field of sockets. The track socket comprises a first shell, a second shell and a grounding electrode connecting sheet, wherein the first shell and the second shell are oppositely arranged and are connected to form a containing cavity, the first shell is provided with a slot communicated with the containing cavity, the second shell is a conductor and is used for being in contact with a grounding electrode plug pin inserted into the containing cavity, and the grounding electrode connecting sheet is electrically connected with the second shell. When the adapter is plugged into the power rail, the grounding pin of the adapter can be directly contacted with the second shell and then connected to the ground wire through the grounding connection piece to realize grounding. Through setting up the second casing as the conductor, replace E utmost point generating line to can reduce the generating line quantity in the power track, reduce cost, and reduced spare part quantity, make the packaging technology simpler, be favorable to automated production.

Description

Power supply rail, adapter and rail socket

Technical Field

The present disclosure relates to the field of sockets, and more particularly to a power rail, an adapter, and a rail socket.

Background

With the improvement of life quality, the electric appliances used by people are more and more, and the number of wall sockets is more and more required. Since the number of general wall sockets is often insufficient, if too many wall sockets are installed, the beauty is impaired. Thus, rail receptacles have evolved.

The track receptacle includes an adapter and an elongated power track. The power supply rail is installed on a wall or the like. The power supply track comprises a shell and a plurality of buses arranged in the shell, wherein the buses comprise an L-pole bus, an N-pole bus and an E-pole bus, the L-pole bus is used for being connected with a live wire, the N-pole bus is used for being connected with a zero line, and the E-pole bus is used for being connected with a ground wire.

The power supply rail has the advantages that the internal space of the shell is limited, more buses are arranged to occupy more space, the material cost is increased, the assembly process is more complex, and the automatic production is not facilitated.

Disclosure of Invention

The embodiment of the disclosure provides a power supply rail, an adapter and a rail socket, which can reduce the number of buses, reduce the cost, simplify the assembly process and facilitate the automatic production. The technical scheme is as follows:

in a first aspect, an embodiment of the present disclosure provides a power supply rail, where the power supply rail includes a first housing, a second housing, and a ground connection piece, where the first housing and the second housing are arranged opposite to each other and are connected to form a housing cavity, the first housing has a slot that is communicated with the housing cavity, and the second housing is a conductor and is used for contacting with a ground plug pin inserted into the housing cavity, and the ground connection piece is electrically connected to the second housing.

Optionally, the inner surface of the second housing has a protective coating, and the protective coating is located outside of an orthographic projection of the slot on the inner surface of the second housing.

Optionally, a connection between the ground connection piece and the inner surface of the second housing is at least partially located in an orthographic projection of the slot on the inner surface of the second housing.

Optionally, the earth electrode connection piece comprises a fixed part and a conductive arm which are connected, wherein the fixed part is parallel to the inner surface of the second shell and is attached to the inner surface of the second shell.

Optionally, one end of the conductive arm is connected to the fixing portion, the other end of the conductive arm extends out relative to the end of the accommodating cavity, and the plane of the conductive arm is perpendicular to the inner surface of the second housing.

Optionally, the power supply rail further includes a first busbar and a second busbar, the first busbar and the second busbar are located in the accommodating cavity and are both insulated from the second housing, the ground connection piece is located between the first busbar and the second busbar, and the conductive arm, the first busbar and the second busbar are parallel to each other.

Optionally, the power supply rail further includes a first insulation groove and a second insulation groove, the first insulation groove and the second insulation groove are located on two sides of the orthographic projection of the slot on the inner surface of the second shell, and are both connected with the second shell, an opening of the first insulation groove is opposite to an opening of the second insulation groove, the first bus bar is located in the first insulation groove, and the second bus bar is located in the second insulation groove.

Optionally, the second casing includes bottom plate, first trip and second trip, the bottom plate with the slot relative arrangement, first trip with the second trip is located the bottom plate is close to one side of slot, first insulation groove with first trip joint, the second insulation groove with second trip joint.

In a second aspect, an embodiment of the present disclosure further provides an adapter of a track socket for connection with the power track of the first aspect, the adapter including an adapter body, an insertion plate, and a ground pin, one side of the insertion plate being connected to the adapter body, the other side of the insertion plate having a receiving slot, the ground pin being located in the receiving slot and being retractable with respect to the insertion plate.

In a third aspect, embodiments of the present disclosure further provide a rail receptacle, the rail receptacle including the power rail of the first aspect and the adapter of the second aspect, the insertion plate of the adapter being located in the slot, the earth pin being in abutment with the second housing.

The technical scheme provided by the embodiment of the disclosure has the beneficial effects that at least:

through arranging first casing and second casing relatively and linking to each other, the earth electrode connection piece links to each other with the second casing, has the slot on the first casing, and the second casing is the conductor, when inserting the adapter to power track, the earth electrode bolt of adapter can directly contact with the second casing, then is connected to the ground wire realization ground through the earth electrode connection piece. Through setting up the second casing as the conductor, replace E utmost point generating line to can reduce the generating line quantity in the power track, reduce cost, and reduced spare part quantity, make the packaging technology simpler, be favorable to automated production.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 is a schematic structural view of a track socket according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a power rail provided in an embodiment of the present disclosure;

FIG. 3 is a cross-sectional view I-I of FIG. 1;

FIG. 4 is a schematic view of the inner surface of a second housing provided by an embodiment of the present disclosure;

FIG. 5 is a schematic view of a partial structure of a power rail provided by an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a partial structure of a power rail provided by an embodiment of the present disclosure;

fig. 7 is a schematic structural view of an adapter of a track jack provided in an embodiment of the present disclosure.

Detailed Description

For the purposes of clarity, technical solutions and advantages of the present disclosure, the following further details the embodiments of the present disclosure with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a track socket according to an embodiment of the present disclosure. As shown in fig. 1, the track jack includes a power track 10 and an adapter 20. The adapter 20 is detachably connected to the power rail 10.

Fig. 2 is a schematic structural diagram of a power rail according to an embodiment of the present disclosure. As shown in fig. 2, the power supply rail 10 includes a first housing 11, a second housing 12, and a ground connection piece 13. FIG. 3 is a sectional view I-I of FIG. 1. As shown in fig. 3, the first housing 11 and the second housing 12 are disposed opposite to each other and connected to form a receiving chamber a.

The first housing 11 has a slot 11a communicating with the accommodation chamber a. The slot 11a is used for connection with the adapter 20.

The second housing 12 is a conductor, and the second housing 12 is for contact with a ground pin 23 inserted into the accommodation chamber a. The earth connection piece 13 is electrically connected with the second housing 12.

By arranging and connecting the first housing 11 and the second housing 12 to each other, the earth connection piece 13 is connected to the second housing 12, the first housing 11 has the slot 11a thereon, the second housing 12 is a conductor, and when the adapter 20 is plugged into the power supply rail 10, the earth pin 23 of the adapter 20 can directly contact with the second housing 12, and then be connected to the earth line through the earth connection piece 13 to achieve the earth connection. The second shell 12 is arranged as a conductor to replace an E-pole bus, so that the number of buses in a power supply rail can be reduced, the cost is reduced, the number of parts is reduced, the assembly process is simpler, and the automatic production is facilitated.

As shown in fig. 3, the first housing 11 includes a panel 111 and two side plates 112, the two side plates 112 are located at opposite sides of the panel 111 and are respectively connected to the panel 111, and the panel 111 and the two side plates 112 form a slot-like structure. The slot 11a is located on the panel 111. The second housing 12 is located inside the channel-like structure. By providing the second housing 12 inside the groove-like structure, the first housing 11 can shield the second housing 12 when the power rail 10 is mounted.

Inside the groove-like structure, the panel 111 is further provided with two connecting protrusions 113, and the two connecting protrusions 113 are in a strip shape and are arranged in parallel at intervals. The connection protrusion 113 has a connection groove 113a at the top thereof. The connection protrusion 113 is for connection with the second housing 12.

The first housing 11 may be an insulator, for example, the first housing 11 may be a plastic member to facilitate manufacturing by injection molding or the like.

As shown in fig. 3, the second housing 12 includes a bottom plate 121 and two connection plates 122, and the two connection plates 122 are located at opposite sides of the bottom plate 121 and are respectively connected to the bottom plate 121. The two connection plates 122 are connected to the first housing 11, respectively. The bottom plate 121 is opposite to the slot 11a on the first housing 11, that is, the orthographic projection of the slot 11a on the plane of the bottom plate 121 is located on the bottom plate 121. The earth pin 23 is in contact with the base plate 121 when the adapter 20 is connected to the power rail 10.

As shown in fig. 3, the connection plate 122 and the connection protrusion 113 may be connected by a screw. The surface of the connection plate 122 adjacent to the panel 111 has a second rib 1221, and the second rib 1221 is located in the connection groove 113a of the connection protrusion 113. The second protrusions 1221 are engaged with the connecting grooves 113a to perform a positioning function when the second housing 12 and the first housing 11 are assembled. In addition, the gap can be reduced, and dust or the like is prevented from entering the accommodation chamber a from the gap between the connection plate 122 and the connection protrusion 113 during use of the power supply rail 10.

The second housing 12 may be a metal structural member, for example, the second housing 12 may be made of a metal such as copper or aluminum. The second shell 12 is made of metal, so that the second shell 12 has electrical conductivity, and the metal has the characteristic of quick heat conduction, and is beneficial to improving the heat dissipation capacity of the power rail 10.

As shown in fig. 3, the orthographic projection of the earth connection piece 13 on the inner surface of the second housing 12 is at least partially located within the orthographic projection of the slot 11a on the inner surface of the second housing 12.

The earth pin 23 of the adapter 20 is inserted into the accommodation chamber a from the insertion groove 11a of the first housing 11, and contacts with the bottom plate 121. That is, the position where the bottom plate 121 contacts the earth pin 23 is located within the orthographic projection of the slot 11a on the inner surface of the second housing 12. The earth connection piece 13 is connected to the bottom plate 121, and the orthographic projection of the earth connection piece 13 on the inner surface of the second shell 12 is at least partially located in the orthographic projection of the slot 11a on the inner surface of the second shell 12, so that the earth connection piece 13 is relatively close to the position on the bottom plate 121, which is contacted with the earth connection bolt 23, when the electrical circuit connected with the adapter 20 is abnormal, and the earth connection bolt 23 is electrified, a shorter current channel can be formed between the earth connection bolt 23 and the earth connection piece 13, and the reliability of grounding is improved.

Fig. 4 is a schematic view of the inner surface of a second housing provided by an embodiment of the present disclosure, and further illustrating the ground connection tab 13. As shown in fig. 4, the inner surface of the second housing 12 has a protective coating 120, and the protective coating 120 is located outside the orthographic projection of the slot 11a on the inner surface of the second housing 12. The filled area in fig. 4 illustrates the protective coating 120, and the blank area illustrates the orthographic projection of the slot 11a on the inner surface of the second housing 12, and also illustrates the area of the inner surface of the second housing 12 not covered by the protective coating 120.

By providing the protective coating 120 to protect the second housing 12, the protective coating 120 is located outside the orthographic projection of the slot 11a on the inner surface of the second housing 12, so that the contact between the earth pin 23 and the second housing 12 can be avoided from being affected by the protective coating 120, and the resistance can be reduced.

The protective coating 120 may also be located on the outer surface of the second housing 12. For example, all surfaces of the slot 11a other than the front projection of the inner surface of the second housing 12 may be covered with the protective coating 120 to increase the protection range.

Illustratively, the protective coating 120 may be an insulating coating, an oxidation-resistant coating, or the like.

As shown in fig. 4, the connection between the earth connection piece 13 and the inner surface of the second housing 12 is at least partially located in the orthographic projection of the slot 11a on the inner surface of the second housing 12. This enables the connection of the ground connection tab 13 to the inner surface of the second housing 12 to be in direct contact with the second housing 12, avoiding an increase in ground resistance due to the barrier of the protective coating 120.

Fig. 5 is a schematic partial structure of a power rail according to an embodiment of the present disclosure. At least the first housing 10 is omitted in fig. 5. As shown in fig. 5, the earth connection piece 13 is arranged at one end of the accommodation chamber a. The ground connection piece 13 includes a fixing portion 131 and a conductive arm 132 connected to each other, and the fixing portion 131 is connected to the second housing 12. The fixing portion 131 is parallel to the inner surface of the second housing 12, and the fixing portion 131 is attached to the inner surface of the second housing 12. This can increase the contact area between the fixing portion 131 and the inner surface of the second housing 12, reduce the contact resistance, and ensure good grounding of the second housing 12.

As shown in fig. 5, one end of the conductive arm 132 is connected to the fixing portion 131, and the other end of the conductive arm 132 protrudes with respect to the end of the accommodation chamber a. The plane in which the conductive arm 132 lies is perpendicular to the inner surface of the second housing 12.

The conductive arm 132 extends from the end of the housing a, and can be easily connected to the ground via the pole connection piece 13. The conductive arm 132 is flat, and the conductive arm 132 is arranged perpendicular to the inner surface of the second housing 12, so that the L-pole bus and the N-pole bus can be arranged in space as large as possible on two sides of the ground electrode connecting sheet 13, and a safety distance as large as possible is provided among the conductive arm 132, the L-pole bus and the N-pole bus.

As shown in fig. 5, the power supply rail 10 further includes a first bus bar 14 and a second bus bar 15, the first bus bar 14 and the second bus bar 15 being located in the accommodation chamber a, the first bus bar 14 and the second bus bar 15 being insulated from the second housing 12.

One ends of the first bus bar 14 and the second bus bar 15 near the ground connection piece 13 may protrude with respect to the end of the accommodation chamber a. One of the first and second bus bars 14, 15 may be an L-pole bus bar for connection to a live line and the other may be an N-pole bus bar for connection to a neutral line. By extending the conductive arm 132, the first busbar 14 and the second busbar 15 from the same end of the receiving cavity a, the wiring of the power supply rail can be facilitated.

The ground connection tab 13 is located between the first busbar 14 and the second busbar 15, and the conductive arm 132, the first busbar 14 and the second busbar 15 are parallel to each other. The conductive arms 132 are arranged in parallel, so that the distances from the conductive arms 132 to the first bus 14 and the second bus 15 are as large as possible, the safety is improved, and the short circuit between one of the first bus 14 and the second bus 15 and the ground electrode connecting sheet 13 is avoided.

As shown in fig. 2 and 5, the power supply rail 10 further includes a first end cap 181 and a junction box 19, the first end cap 181 being located at an end of the accommodation chamber a and being connected to the second housing 12. The first end cover 181 has 3 bar-shaped openings 181a, and the conductive arms 132, the first bus bar 14 and the second bus bar 15 respectively extend from the 3 bar-shaped openings 181 a. The first end cap 181 functions to close the accommodation chamber a.

The power rail 10 may further include a second end cap 182, the second end cap 182 being located at an end of the receiving cavity a remote from the first end cap 181 and being connected to the first housing 11 and the second housing 12.

Fig. 6 is a schematic partial structure of a power rail according to an embodiment of the present disclosure. As shown in fig. 6, the junction box 19 is located in a groove-like structure surrounded by the first housing 11, and is located on a side of the first end cap 181 remote from the accommodation chamber a. The conductive arm 132, the first bus bar 14, and the second bus bar 15 are inserted in the junction box 19. The junction box 19 is used to connect with the live, neutral, ground wires to connect the power rail 10 into the circuit.

As shown in fig. 3, the first bus bar 14 and the second bus bar 15 are located on both sides of the orthographic projection of the slot 11a on the inner surface of the second housing 12. The earth connection tab 13 is located between the first busbar 14 and the second busbar 15. By arranging the earth electrode connecting sheet 13 at the intermediate position, the distance between the first bus bar 14 and the second bus bar 15 is increased as much as possible, which is advantageous for improving the electric safety.

As shown in fig. 3, the power supply rail 10 further includes a first insulation groove 16 and a second insulation groove 17. The first insulating groove 16 and the second insulating groove 17 are located on both sides of the orthographic projection of the insertion groove 11a on the inner surface of the second housing 12, and are connected to the second housing 12. The opening of the first insulating groove 16 is opposite to the opening of the second insulating groove 17, the first bus bar 14 is located in the first insulating groove 16, and the second bus bar 15 is located in the second insulating groove 17.

The second housing 12 in the related art is insulated, and the first bus bar 14 and the second bus bar 15 may be directly mounted on the second housing 12 to be in contact with the second housing 12. In the embodiment of the disclosure, the second housing 12 is a conductor, the first bus bar 14 is separated from the second housing 12 by providing the first insulation slot 16, and the second bus bar 15 is separated from the second housing 12 by providing the second insulation slot 17, so that the first bus bar 14 and the second bus bar 15 are insulated from the second housing 12, thereby ensuring the electrical safety.

The structures of the first insulation groove 16 and the second insulation groove 17 may be mirror images of each other. The first insulating slot 16 is U-shaped, separating the first busbar 14 and the second housing 12 in multiple directions.

As shown in fig. 3, the second housing 12 further includes a first hook 123 and a second hook 124. The bottom plate 121 is disposed opposite to the slot 11a, and the first hook 123 and the second hook 124 are located on a side of the bottom plate 121 near the slot 11a. The first insulation slot 16 is clamped with the first clamping hook 123, and the second insulation slot 17 is clamped with the second clamping hook 124.

By providing the first hook 123 and the second hook 124, the first insulation groove 16 and the second insulation groove 17 are respectively fixed, and loosening of the first insulation groove 16 and the second insulation groove 17 is avoided. The clamping hooks are adopted for fixing, so that the dismounting is convenient, and structures such as screws do not need to be additionally arranged.

As shown in fig. 3, the first hook 123 includes a vertical plate 1231 and a baffle plate 1232, the vertical plate 1231 is connected to the bottom plate 121, and the baffle plate 1232 is connected to the vertical plate 1231. The baffle 1232, the vertical plate 1231 and the bottom plate 121 enclose a chute in which the first insulation slot 16 is located.

The first hook 123 and the bottom plate 121 form a sliding slot, which can limit the first insulation slot 16 from multiple directions, so as to avoid loosening of the first insulation slot 16. And when the first insulating groove 16 is installed, the first insulating groove 16 can be slid into the chute from the end of the chute, so that the installation is convenient.

The structures of the second hook 124 and the first hook 123 may be mirror images of each other.

As shown in fig. 3, the inner side wall of the chute is provided with a first rib 125, the outer side wall of the first insulation slot 16 is provided with a clamping slot 16a, and the first rib 125 is positioned in the clamping slot 16a.

The first rib 125 cooperates with the slot 16a to prevent the first insulation slot 16 from being removed from the chute. And also plays a role of guiding to ensure the mounting accuracy of the first bus bar 14.

As an example, the two opposite side walls of the chute have first ribs 125, and the two opposite outer side walls of the first insulation slot 16 have clamping slots 16a.

The second hook 124 may also have a first rib 125, and the outer sidewall of the second insulation slot 17 may also have a slot 16a, so as to facilitate the installation of the second insulation slot 17.

Fig. 7 is a schematic structural view of an adapter of a track jack provided in an embodiment of the present disclosure. As shown in fig. 7, the adapter includes an adapter body 21, an insertion plate 22, and a ground pin 23. One side of the insertion plate 22 is connected to the adapter body 21, and the other side of the insertion plate 22 has a receiving groove in which the earth pin 23 is partially located and can be extended and contracted with respect to the insertion plate 22.

In the related art, an insert sleeve is usually arranged on the E-pole bus, and a ground pole plug pin is inserted into the insert sleeve to form electric connection with the E-pole bus. In this example, the second housing 12 is directly used as the E-pole bus, the earth pin 23 can telescope relative to the insertion plate 22, and the protruding length of the earth pin 23 relative to the accommodating groove can be matched with the distance between the insertion plate 22 and the second housing 12, so that the earth pin 23 and the second housing 12 keep good contact.

The disclosed embodiment also provides a track socket comprising the aforementioned power track and an adapter, the insert plate 22 of which is located in the slot 11a, and the earth pin 23 abuts against the second housing 12.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The terms "first," "second," "third," and the like in the description and in the claims, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, is intended to mean that elements or items that are present in front of "comprising" or "comprising" are included in the word "comprising" or "comprising", and equivalents thereof, without excluding other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to denote relative positional relationships, which may also change accordingly when the absolute position of the object to be described changes.

The foregoing description of the preferred embodiments of the present disclosure is provided for the purpose of illustration only, and is not intended to limit the disclosure to the particular embodiments disclosed, but on the contrary, the intention is to cover all modifications, equivalents, alternatives, and alternatives falling within the spirit and principles of the disclosure.

Claims (10)

1. The utility model provides a power supply track, its characterized in that includes first casing (11), second casing (12) and earth connection piece (13), first casing (11) with second casing (12) relative arrangement just links to each other and forms one and hold chamber (A), first casing (11) have with hold communicating slot (11 a) in chamber (A), second casing (12) are the conductor for with insert earth bolt (23) contact in holding chamber (A), earth connection piece (13) with second casing (12) electrical property links to each other.

2. The power rail according to claim 1, characterized in that the inner surface of the second housing (12) is provided with a protective coating (120), and that the protective coating (120) is located outside the orthographic projection of the slot (11 a) at the inner surface of the second housing (12).

3. The power rail according to claim 2, characterized in that the connection of the earth connection piece (13) to the inner surface of the second housing (12) is at least partially located in the orthographic projection of the slot (11 a) in the inner surface of the second housing (12).

4. A power rail according to any one of claims 1-3, characterized in that the pole connection piece (13) comprises a connecting fixing part (131) and a conductive arm (132), the fixing part (131) being parallel to the inner surface of the second housing (12) and being in abutment with the inner surface of the second housing (12).

5. The power rail according to claim 4, characterized in that one end of the conductive arm (132) is connected to the fixing portion (131), the other end of the conductive arm (132) protrudes with respect to the end of the housing cavity (a), and the plane of the conductive arm (132) is perpendicular to the inner surface of the second housing (12).

6. The power rail according to claim 5, further comprising a first busbar (14) and a second busbar (15), the first busbar (14) and the second busbar (15) being located in the receiving cavity (a) and being insulated from the second housing (12), the earth connection tab (13) being located between the first busbar (14) and the second busbar (15), the conductive arm (132), the first busbar (14) and the second busbar (15) being parallel to each other.

7. The power rail according to claim 6, further comprising a first insulation groove (16) and a second insulation groove (17), wherein the first insulation groove (16) and the second insulation groove (17) are located on both sides of the orthographic projection of the slot (11 a) on the inner surface of the second housing (12) and are both connected to the second housing (12), wherein the opening of the first insulation groove (16) is opposite to the opening of the second insulation groove (17), wherein the first bus bar (14) is located in the first insulation groove (16), and wherein the second bus bar (15) is located in the second insulation groove (17).

8. The power rail according to claim 7, wherein the second housing (12) includes a bottom plate (121), a first hook (123) and a second hook (124), the bottom plate (121) is disposed opposite to the slot (11 a), the first hook (123) and the second hook (124) are located at a side of the bottom plate (121) near the slot (11 a), the first insulation slot (16) is clamped with the first hook (123), and the second insulation slot (17) is clamped with the second hook (124).

9. An adapter for a rail socket for connection with a power supply rail according to any one of claims 1-8, characterized in that the adapter comprises an adapter body (21), an insert plate (22) and a ground pin (23), one side of the insert plate (22) being connected to the adapter body (21), the other side of the insert plate (22) having a receiving slot, the ground pin (23) being partly located in the receiving slot and being retractable relative to the insert plate (22).

10. A track socket comprising a power track as claimed in any one of claims 1 to 8 and an adapter as claimed in claim 9, the insert plate (22) of the adapter being located in the slot (11 a), the earth pin (23) being in abutment with the second housing (12).