Anti-rotation structure for plate material

Abstract

To improve workability in mounting by preventing a plurality of plate materials from rotating relatively to each other even when the plurality of plate materials are temporarily fixed at one fastening point.SOLUTION: A first plate 35 is overlapped in a plate thickness direction on a portion of a second plate 34. One location of the overlapping portions of the first plate 35 and the second plate 34 is fastened by one fastening member 41. The second plate 34 is formed with protruding portions 34c1, 34c2, 34c3, and 34c4 that protrude toward the side where the first plate 35 overlaps therewith and abut against the edge of the first plate 35.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a rotation prevention structure for a plate material. [Background technology]

[0002] For example, a residential distribution board has an internal unit inside a housing attached to the wall of a house (see Non-Patent Document 1). The internal unit has a main breaker, branch breakers, solar breakers, terminal blocks, etc. (hereinafter referred to as breakers), and the breakers are attached to a mounting plate made of sheet metal. This mounting plate is then screwed to the housing. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Temper Industrial Co., Ltd., "Temper General Catalog 2023-2024", page E-8 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the main breaker, branch breakers, solar breakers, and terminal blocks are mounted on a mounting plate, arranged side by side on the left and right sides of the housing. However, some homes do not have solar breakers installed, and in such cases, there is no need to install a solar breaker, so the mounting plate is shaped so that a solar breaker cannot be installed. Only the main breaker and branch breakers, which are required for every home, are mounted on the mounting plate, and a relatively small mounting plate is used.

[0005] To standardize parts, a small mounting plate is used that can only mount the main breaker and branch breaker, but if you want to install an additional solar breaker, a separate mounting plate is required to mount the solar breaker.In other words, two mounting plates are sometimes screwed to the housing: a first mounting plate that can only mount the main breaker and branch breaker, and a second mounting plate that can mount the solar breaker.

[0006] However, because the first mounting plate and the second mounting plate are made of separate members, the screwing process to the housing may be complicated. That is, the main breaker and branch breaker attached to the first mounting plate and the solar breaker attached to the second mounting plate are housed in the housing in a wired state, so the first mounting plate and the second mounting plate need to be integrated before screwing them to the housing. If the relative positional relationship between the first mounting plate and the second mounting plate changes before they are screwed to the housing, the screw holes will not align when fastening them to the housing, so a temporary fixing structure is needed to prevent the relative positional relationship between the first mounting plate and the second mounting plate from changing.

[0007] One possible temporary fixing structure is one in which the first and second mounting plates are fastened together with screws at multiple locations. Fastening the plates together at multiple locations prevents one mounting plate from rotating relative to the other before they are screwed to the housing, and prevents problems such as misaligned screw holes when fastening them to the housing. However, fastening the first and second mounting plates together at multiple locations requires multiple screws, which increases the number of parts and the labor required.

[0008] If only one screw is used to avoid an increase in the number of parts and labor required, one plate will easily rotate relative to the other plate around the screw, resulting in the screw holes not aligning when fastening to the housing. In particular, since housings are often installed in high places, if one of the first and second mounting plates rotates relative to the other when lifted, subsequent alignment becomes difficult and workability is extremely poor.

[0009] Furthermore, similar problems arise when the first and second mounting plates are integrated and attached to a member other than a residential distribution board.

[0010] The present disclosure has been made in consideration of such points, and its purpose is to improve workability during installation by preventing the plate materials from rotating relative to each other, even when multiple plate materials are temporarily fixed at a single fastening point. [Means for solving the problem]

[0011] To achieve the above object, one aspect of the present disclosure can be based on a plate anti-rotation structure that suppresses relative rotation of a first plate and a second plate attached to a common mounting body. The first plate is overlapped in the plate thickness direction with a portion of the second plate. The overlapping portions of the first plate and the second plate are fastened together at one location by a single fastening member. The second plate has a protruding portion that protrudes toward the side where the first plate overlaps and abuts against an edge of the first plate.

[0012] With this configuration, the first plate and the second plate are fastened together with one fastening member, thereby reducing the number of parts and labor required to temporarily fasten the first plate and the second plate. When the first plate and the second plate are fastened together, for example, if the first plate tries to rotate relative to the second plate around the fastening member, the protrusion formed on the second plate abuts against the edge of the first plate, thereby suppressing the rotation.

[0013] The fastening member may fasten together vertically intermediate portions of the first plate member extending in the vertical direction and the second plate member extending in the vertical direction. In this case, the protrusion may include an upper protrusion that abuts against a portion of the edge of the first plate member above the fastening member, and a lower protrusion that abuts against a portion of the edge of the first plate member below the fastening member. With this configuration, rotation in both directions around the fastening member can be suppressed by the upper protrusion and the lower protrusion.

[0014] The fastening member may be a screw. In this case, one of the first plate and the second plate may have a through-hole through which the shank of the screw is inserted, and the other may have a threaded hole into which the shank of the screw is threaded. That is, the first plate and the second plate can be fastened together simply by inserting the shank of the screw into the through-hole and threading it into the threaded hole, thereby reducing the amount of work required. In this configuration, threaded holes are formed in the plate members, and the threads formed on the inner surface of the threaded holes are prone to stripping, making it difficult to increase the tightening torque of the screw, which may result in relative rotation between the first plate and the second plate. In this embodiment, relative rotation can be suppressed by abutting the protruding portion of the second plate against the edge of the first plate without relying on the tightening torque of the screw. Therefore, a sufficient anti-rotation effect can be obtained even in a structure where the threads are prone to stripping.

[0015] A first fastening portion fastened to the mounting body may be provided on the side of the first plate opposite the side overlapping the second plate. Furthermore, a second fastening portion fastened to the mounting body may be provided on the side of the second plate opposite the side overlapping the first plate. That is, the fastening portion to the mounting body is located away from the side fastened by a single fastening member, resulting in a structure that is prone to rotation around the single fastening member during fastening to the mounting body. In this aspect, even with such a structure that is prone to rotation, relative rotation can be suppressed by abutting the protruding portion of the second plate against the edge of the first plate, thereby providing a sufficient anti-rotation effect.

[0016] The protrusion may be press-molded onto the second plate material. With this configuration, the protrusion can be formed simultaneously with molding of the second plate material.

[0017] The first plate and the second plate may each be attached with a device that is connected to each other by electrical wiring. [Effects of the Invention]

[0018] As described above, the first plate material and the second plate material are fastened together with one fastening member, and a protrusion is formed on the second plate material that abuts against the edge of the first plate material. Therefore, even when the first plate material and the second plate material are temporarily fixed together at one fastening point, it is possible to prevent the first plate material and the second plate material from rotating relative to each other, thereby improving workability when attaching them to the mounting body. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a residential distribution board to which a plate anti-rotation structure according to an embodiment of the present invention is applied. [Figure 2] FIG. 2 is a front view of a residential distribution board to which a plate anti-rotation structure is applied. [Figure 3] FIG. 3 is a front view of the housing. [Figure 4] FIG. 4 is an exploded perspective view of the left plate and the intermediate plate. [Figure 5] FIG. 5 is a perspective view of the left plate and the intermediate plate as seen from the back side. [Figure 6] FIG. 6 is a front view of the left plate and the intermediate plate. [Figure 7] FIG. 7 is a rear view of the left plate and the intermediate plate. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present invention, its applications, or its uses.

[0021] Fig. 1 is a perspective view of a residential distribution board 1 to which a plate anti-rotation structure according to an embodiment of the present invention is applied, and Fig. 2 is a front view of the residential distribution board 1. The residential distribution board 1 is used while attached to a wall of a house (not shown), and includes a housing 2 and an internal unit 3. A lid for covering the internal unit 3 is omitted in Figs. 1 and 2, and an actual residential distribution board 1 also includes an openable and closable lid.

[0022] In this embodiment, as shown in FIG. 1, the front side and the back side are defined, with the back side of the housing 2 being the side that is attached to the wall and the front side being the side that is opened and closed by the lid. The front side of the housing 2 can also be referred to as the front side, and the back side of the housing 2 can also be referred to as the back side. Furthermore, as shown in FIGS. 1 and 2, the left side when viewing the residential distribution board 1 from the front side is referred to as the left, and the right side is referred to as the right. The left-right direction of the residential distribution board 1 can also be referred to as the width direction. The definition of the directions of the residential distribution board 1 is for convenience of explanation and does not limit the present invention.

[0023] 3, the housing 2 has a rectangular frame shape made of, for example, a resin material, and has an upper side 21 and a lower side 22 extending in the left-right direction, and a left side 23 and a right side 24 extending in the up-down direction. The left side 23 extends from the left end of the upper side 21 to the left end of the lower side 22. The right side 24 extends from the right end of the upper side 21 to the right end of the lower side 22. The left-right dimensions of the upper side 21 and the lower side 22 are set longer than the up-down dimensions of the left side 23 and the right side 24. Therefore, the housing 2 has a shape that is long in the left-right direction.

[0024] The housing 2 also has a left-side intermediate connecting portion 25 and a right-side intermediate connecting portion 26. The left-side intermediate connecting portion 25 extends from a portion of the top edge portion 21 that is closer to the left of the left-right center to a portion of the bottom edge portion 22 that is closer to the left of the left-right center, connecting the top edge portion 21 and the bottom edge portion 22. The right-side intermediate connecting portion 26 extends from a portion of the top edge portion 21 that is closer to the right of the left-right center to a portion of the bottom edge portion 22 that is closer to the right of the left-right center, connecting the top edge portion 21 and the bottom edge portion 22. The left-side intermediate connecting portion 25 and the right-side intermediate connecting portion 26 may be provided as needed.

[0025] An upper left fastening hole 23a and a lower left fastening hole 23b are formed in the upper and lower parts of the left side 23, respectively, to fasten the left side plate material of the inner assembly 3 (described later). An upper right fastening hole 24a and a lower right fastening hole 24b are formed in the upper and lower parts of the right side 24, respectively, to fasten the right side plate material of the inner assembly 3 (described later). The upper left fastening hole 23a, the lower left fastening hole 23b, the upper right fastening hole 24a, and the lower right fastening hole 24b each open toward the front side and are formed to a predetermined depth toward the back side.

[0026] The upper and lower portions of the left intermediate connecting portion 25 are respectively formed with a first upper fastening hole 25a and a first lower fastening hole 25b, through which the left and middle plates of the inner assembly 3, which will be described later, are fastened together. The upper portion of the right intermediate connecting portion 26 is respectively formed with a second upper fastening hole 26a, through which the right and middle plates of the inner assembly 3, which will be described later, are fastened together. The first upper fastening hole 25a, the first lower fastening hole 25b, and the second upper fastening hole 26a each open toward the front side and are formed to a predetermined depth toward the back side.

[0027] 1 and 2, the internal unit 3 has a right-side breaker 31 disposed on the right side, a central breaker 32 disposed in the center in the left-right direction, a left-side breaker 33 disposed on the left side, a left-side plate member 34, an intermediate plate member 35, and a right-side plate member 36. The right-side breaker 31, the central breaker 32, and the left-side breaker 33 are aligned in the left-right direction. The right-side breaker 31 and the central breaker 32 are connected to each other by electrical wiring. The central breaker 32 and the left-side breaker 33 are also connected to each other by electrical wiring.

[0028] The types of the right-side breaker 31, the central breaker 32, and the left-side breaker 33 are not particularly limited, but in this embodiment, as an example, a case will be described in which the right-side breaker 31 is a plurality of branch breakers, the central breaker 32 is a main breaker, and the left-side breaker 33 is a solar breaker. Also, the order of the branch breakers, main breaker, and solar breaker is not particularly limited. The breakers are an example of equipment, but in addition to or instead of breakers, terminal blocks (equipment) and other electronic devices (such as equipment with communication functions) may be included.

[0029] The left plate member 34 is disposed in an area to the left of the center in the left-right direction inside the housing 2, and the left breaker 33 is attached to the left plate member 34. The right plate member 36 is disposed in an area to the right of the center in the left-right direction inside the housing 2, and the right breaker 31 is attached to the right plate member 36. The middle plate member 35 is disposed in the center in the left-right direction inside the housing 2, and the center breaker 32 is attached to the middle plate member 35. In this way, different breakers 31 to 33 are attached to the multiple plate members 34 to 36, respectively.

[0030] Before attaching the internal unit 3 to the housing 2, the right breaker 31, the center breaker 32, the left breaker 33, the left plate member 34, the middle plate member 35, and the right plate member 36 are integrated. Therefore, after attaching the housing 2 to the wall of the house, the worker lifts the internal unit 3, places it in the housing 2, and fixes it to the housing 2.

[0031] During this operation, the left plate member 34, the intermediate plate member 35, and the right plate member 36 are attached to the common housing 2. The housing 2 is an example of an attachment body. The left plate member 34, the intermediate plate member 35, and the right plate member 36 are formed so as to extend in the vertical and horizontal directions when attached to the housing 2. The left plate member 34, the intermediate plate member 35, and the right plate member 36 are formed by press-forming a metal material such as a steel plate. The lower limit of their thicknesses is not particularly limited, but is set to, for example, 0.5 mm or more, or 0.8 mm or more. The upper limit of the thicknesses of the left plate member 34, the intermediate plate member 35, and the right plate member 36 is also not particularly limited, but is set to, for example, 1.5 mm or less, or 1.2 mm or less. The intermediate plate member 35 is an example of a first plate member. The left plate member 34 is an example of a second plate member.

[0032] The left portion of the intermediate plate material 35 is overlapped from the back side in the plate thickness direction against the right portion of the left plate material 34. Also, the right portion of the intermediate plate material 35 is overlapped from the front side in the plate thickness direction against the left portion of the right plate material 36.

[0033] 4, a first fastening hole (first fastening portion) 35a that is fastened to the right intermediate connecting portion 26 of the housing 2 is provided at the upper part of the intermediate plate member 35 on the opposite side (right side) from the side where it overlaps with the left plate member 34. Second fastening holes (second fastening portions) 34a that are fastened to the left side portion 23 of the housing 2 are provided at the top and bottom of the left plate member 34 on the opposite side (left side) from the side where it overlaps with the intermediate plate member 35.

[0034] Third fastening holes 35b are formed in the upper and lower left parts of the intermediate plate 35, respectively, for fastening to the left intermediate connecting part 25 of the housing 2. Fourth fastening holes 34b are formed in the upper and lower right parts of the left plate 34, respectively, for fastening to the left intermediate connecting part 25 of the housing 2.

[0035] The upper third fastening hole 35b and the upper fourth fastening hole 34b are aligned with each other and are fastened to the upper portion of the left intermediate connecting part 25 by a common screw 42 (shown in FIG. 2). The screw 42 is, for example, a tapping screw or the like and is designed to be threaded into the first upper fastening hole 25a (shown in FIG. 3). The lower third fastening hole 35b and the lower fourth fastening hole 34b are aligned with each other and are fastened to the lower portion of the left intermediate connecting part 25 by a common screw 43. The screw 43 is, for example, a tapping screw or the like and is designed to be threaded into the first lower fastening hole 25b. This allows the overlapping portions of the intermediate plate member 35 and the left side plate member 34 to be fastened together by the screws 42, 43.

[0036] The upper second fastening hole 34a is fastened to the upper portion of the left side portion 23 by a screw 44. The screw 44 is, for example, a tapping screw or the like, and is adapted to be screwed into the upper left fastening hole 23a. The lower second fastening hole 34a is fastened to the lower portion of the left side portion 23 by a screw 45. The screw 45 is, for example, a tapping screw or the like, and is adapted to be screwed into the lower left fastening hole 23b.

[0037] 2, a fifth fastening hole 36a is formed on the left side of the right plate 36, which coincides with the first fastening hole 35a of the intermediate plate 35. The first fastening hole 35a and the fifth fastening hole 36a are fastened to the upper portion of the right intermediate connecting part 26 by a common screw 46. The screw 46 is, for example, a tapping screw or the like, and is adapted to be threaded into the second upper fastening hole 26a.

[0038] Sixth fastening holes 36b are formed in the upper and lower right portions of the right side of the right plate member 36, respectively, to fasten to the right side portion 24 of the housing 2. The upper sixth fastening hole 36b is fastened to the upper portion of the right side portion 24 with a screw 47. The screw 47 is, for example, a tapping screw or the like, and is adapted to be threaded into the upper right fastening hole 24a. The lower sixth fastening hole 36b is fastened to the lower portion of the right side portion 24 with a screw 48. The screw 48 is, for example, a tapping screw or the like, and is adapted to be threaded into the lower right fastening hole 24b.

[0039] 2, the intermediate plate 35 and the right side plate 36 are stacked on top of each other in the plate thickness direction and fastened together at multiple locations spaced apart in the vertical direction with screws 40. Fastening together at multiple locations spaced apart in the vertical direction with screws 40 prevents the intermediate plate 35 and the right side plate 36 from rotating relative to each other.

[0040] Meanwhile, the left plate material 34 and the intermediate plate material 35 are fastened together at one location of the overlapping portions of the left plate material 34 and the intermediate plate material 35 with a single screw (fastening member) 41, with the left portion of the intermediate plate material 35 overlapping the right portion of the left plate material 34 from behind in the plate thickness direction. As shown in FIG. 4 , the screw 41 fastens the left plate material 34 and the intermediate plate material 35 together at their vertically middle portions. In the portion of the left plate material 34 where the intermediate plate material 35 overlaps, an insertion hole 34d is formed so as to penetrate the left plate material 34 in the plate thickness direction, and a shank 41b of the screw 41 protruding from a head 41a of the screw 41 is inserted through the insertion hole 34d. In the portion of the intermediate plate material 35 where the left plate material 34 overlaps, a screw hole 35d is formed so as to penetrate the intermediate plate material 35 in the plate thickness direction, and the shank 41b of the screw 41 is screwed into the insertion hole 34d. A screw thread is formed on the inner peripheral surface of the screw hole 35d.

[0041] The shank 41b of the screw 41 is inserted through the insertion hole 34d of the left plate 34 and then threaded into the screw hole 35d of the intermediate plate 35, thereby fastening the left plate 34 and the intermediate plate 35 at only one location with only one screw 41. Therefore, depending on how force is applied, the left plate 34 may rotate relative to the intermediate plate 35 around the screw 41, or the intermediate plate 35 may rotate relative to the left plate 34 around the screw 41. In particular, because the screw hole 35d is formed in sheet metal, the threads are easily stripped, making it difficult to increase the tightening torque compared to fastening structures using nuts or the like. In other words, there is a risk that the left plate 34 and the intermediate plate 35 may rotate relative to each other. If the left plate 34 and the intermediate plate 35 rotate relative to each other, the first fastening hole 35a and the second fastening hole 34a will be misaligned, requiring additional realignment work, which is complicated.

[0042] To prevent such problems from occurring, this embodiment provides a plate anti-rotation structure that prevents relative rotation between the left plate member 34 and the intermediate plate member 35. Specifically, the left plate member 34 is formed with protrusions 34c1, 34c2, 34c3, and 34c4 that protrude toward the side where the intermediate plate member 35 overlaps and abut the left edge of the intermediate plate member 35. The protrusions 34c1, 34c2, 34c3, and 34c4 are press-formed on the left plate member 34. Therefore, the protrusions 34c1, 34c2, 34c3, and 34c4 can be formed simultaneously with the formation of the left plate member 34. When the protrusions 34c1, 34c2, 34c3, and 34c4 are press-formed, a protrusion provided on a mold (not shown) is pressed from the front side toward the back side of the left plate member 34. As a result, protrusions 34c1, 34c2, 34c3, and 34c4 are formed on the back side of the left plate material 34, while recesses corresponding to the shapes of the protrusions 34c1, 34c2, 34c3, and 34c4 are formed on the front side of the left plate material 34.

[0043] The number of anti-rotation protrusions may be one or more. In this embodiment, multiple anti-rotation protrusions are formed, and the anti-rotation protrusions include two upper protrusions 34c1 and 34c2 that abut on a portion of the left edge of the intermediate plate 35 above the screw 41, and two lower protrusions 34c3 and 34c4 that abut on a portion of the left edge of the intermediate plate 35 below the screw 41. The upper protrusions 34c1 and 34c2 are arranged at intervals from each other in the vertical direction. The lower protrusions 34c3 and 34c4 are also arranged at intervals from each other in the vertical direction. As a result, the protrusions 34c1, 34c2, 34c3, and 34c4 abut at multiple points on the left edge of the intermediate plate 35. Therefore, when the left plate 34 and the intermediate plate 35 attempt to rotate relative to each other, the force from the protrusions 34c1, 34c2, 34c3, and 34c4 acts in a dispersed manner on the left edge of the intermediate plate 35. This suppresses deformation of the left edge of the intermediate plate 35 and deformation of the protrusions 34c1, 34c2, 34c3, and 34c4. The upper protrusion may be formed in one piece or in three or more pieces. The lower protrusion may also be formed in one piece or in three or more pieces. The protrusions may be elongated in the vertical direction or may be circular.

[0044] (Effects of the embodiment) As described above, according to this embodiment, the left plate member 34 and the intermediate plate member 35 are fastened together with one screw 41, thereby reducing the number of parts and labor required to temporarily fasten the left plate member 34 and the intermediate plate member 35. When the left plate member 34 and the intermediate plate member 35 attempt to rotate relatively around the screw 41 while the left plate member 34 and the intermediate plate member 35 are fastened together, the protrusions 34c1, 34c2, 34c3, and 34c4 formed on the left plate member 34 come into contact with the left edge portion of the intermediate plate member 35, thereby suppressing the rotation. This improves the workability when attaching the internal unit 3 to the housing 2.

[0045] In addition, upper protrusions 34c1, 34c2 are formed to be located above the screw 41, and lower protrusions 34c3, 34c4 are formed to be located below the screw 41, so that rotation in both directions around the screw 41 can be suppressed by the upper protrusions 34c1, 34c2 and the lower protrusions 34c3, 34c4.

[0046] The above-described embodiment is merely illustrative in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of equivalence of the claims are within the scope of the present invention. For example, the present invention can be applied to a structure in which a first plate and a second plate are fastened at one location, and in which it is desired to prevent the plate from rotating, in addition to the residential distribution board 1. [Industrial Applicability]

[0047] As described above, the anti-rotation structure for plate materials according to the present invention can be used when the first plate material and the second plate material are fastened at one location. [Explanation of symbols]

[0048] 1. Residential distribution board 2 Housing (mounting body) 32 Central Breaker 33 Left side breaker 34 Left side board (second board) 34a 2nd fastening hole (2nd fastening part) 34c1, 34c2 Upper protrusion 34c3, 34c4 Lower protrusion 34d Insertion hole 35 Intermediate plate (first plate) 35a 1st fastening hole (1st fastening part) 35d screw hole 41 Screws (fastening components) 41b Shaft

Claims

1. A plate anti-rotation structure that suppresses relative rotation of a first plate and a second plate attached to a common attachment body, the first plate material is overlapped with a portion of the second plate material in a plate thickness direction, the first plate material and the second plate material are fastened together at one location of the overlapping portions by one fastening member, A plate anti-rotation structure in which the second plate has a protrusion formed on the side where the first plate overlaps and abuts against the edge of the first plate.

2. The anti-rotation structure for a plate material according to claim 1, the fastening member fastens together vertically intermediate portions of the first plate member extending in the vertical direction and the second plate member extending in the vertical direction, The anti-rotation structure for a plate material, wherein the protrusion includes an upper protrusion that abuts against a portion of the edge of the first plate material above the fastening member, and a lower protrusion that abuts against a portion of the edge of the first plate material below the fastening member.

3. The anti-rotation structure for a plate material according to claim 1, The fastening member is a screw, A plate anti-rotation structure in which one of the first plate and the second plate has a through hole formed therein through which the shank of the screw is inserted, and the other has a screw hole into which the shank of the screw is screwed.

4. 3. The plate anti-rotation structure according to claim 2, a first fastening portion to be fastened to the mounting body is provided on a side of the first plate opposite to a side where the first plate overlaps the second plate, A plate anti-rotation structure, in which a second fastening portion that is fastened to the mounting body is provided on the side of the second plate opposite the side that overlaps the first plate.

5. The anti-rotation structure for a plate material according to claim 1, The protrusion is press-molded on the second plate, thereby preventing rotation of the plate.

6. The anti-rotation structure for a plate material according to claim 1, The structure for preventing rotation of plates, wherein the first plate and the second plate are respectively fitted with devices that are connected to each other by electrical wiring.

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