Electric power box convenient to overhaul for electric power engineering

Abstract

The invention relates to the technical field of power boxes, and discloses a convenient-to-overhaul power box for power engineering, which comprises a box body and a bottom plate, the bottom of the box body is rotatably connected with the bottom plate through a rotating shaft, the front surface of the box body is hinged to a box door through a hinge, and the side edges and the back of the box body are in threaded connection with side plates through bolts. The inner wall of the box body is rotatably connected with a circular plate through a bearing, and the bottom of the inner wall of the box body is fixedly connected with a heat dissipation fan group. Through arrangement of the side plates, when electronic elements in the power box need to be overhauled, the frame of the box body can be completely exposed only by easily disassembling the side plates, and meanwhile, the mounting frame can slide along the limiting frame; the installation frame is moved to the middle position of the box body, more operation space is provided for maintainers, internal electronic elements can be maintained conveniently, and the maintainers can better expose the electronic elements on the installation frame by rotating the box body and flexibly adjusting the visual angle, so that the maintenance efficiency and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power boxes, and in particular to a power box for a power project that is convenient for maintenance. Background Technique

[0002] The power box in the power project is a key device in the power system. It has a protective shell that can effectively resist the interference of external factors such as wind, rain, and dust. Inside, various electrical components are integrated, undertaking the important tasks of power distribution, control, and protection, ensuring stable power transmission, and being widely used in scenarios such as factories, communities, and substations to ensure the orderly supply of electricity.

[0003] The patent application with the application number CN202211085124.5 discloses a high-voltage power project power box that is convenient for maintenance, including a protective housing, an electrical installation housing, a wire harness assembly, a seal, and a drive assembly. An inspection opening is provided on the side wall of the protective housing, an opening is provided on the surface of the seal, first meshing teeth are provided on both the upper and lower sides of the seal, and the drive assembly includes a drive part, a first rotating tube, a second rotating tube, and a transmission part. The first rotating tube is installed at the end of the second rotating tube.

[0004] In the maintenance work of traditional power boxes, the conventional process is to open the box door and repair the faulty parts. However, in actual operation, the electronic components in the power box are often stacked in the power box, and the surrounding space is narrow, making it difficult for maintenance personnel to approach and tools to be used, making the maintenance operation extremely difficult and delaying the power restoration time. Therefore, we propose a power box for a power project that is convenient for maintenance. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a power box for a power project that is convenient for maintenance to solve the problems raised in the above background technique.

[0006] To achieve the above object, the present invention provides the following technical solution: A power box for a power project that is convenient for maintenance, including a box body and a bottom plate. The bottom of the box body is rotatably connected to the bottom plate through a rotating shaft. The front of the box body is hinged to a box door through a hinge. The side and back of the box body are threadedly connected to side plates through bolts. The inner wall of the box body is rotatably connected to a circular plate through a bearing. A heat dissipation fan group is fixedly connected to the bottom of the inner wall of the box body. A partition is provided above the heat dissipation fan group, and the partition is fixedly connected to the inner wall of the box body. It also includes: Fixing bracket, the top of the fixing bracket is fixedly connected to the circular plate, the bottom of the fixing bracket is in contact with the top of the partition, a card slot is opened on the back of the fixing bracket, an installation bracket is arranged on the back of the fixing bracket, the fixing bracket is slidably connected to the installation bracket through the card slot, a limiting bracket is fixedly connected to the inner wall of the fixing bracket, both ends of the limiting bracket penetrate through the installation bracket and are movably inserted into the installation bracket, two groups of snap rings are fixedly connected to the outer surface of the limiting bracket, and the top of the circular plate is fixedly connected to the existing installation fixing bracket to provide support for the circular plate.

[0007] Preferably, connecting brackets are fixedly connected to both the left and right ends of the fixing bracket, an arc-shaped groove is opened in the middle of the connecting bracket, convex columns are fixedly connected to both the left and right ends of the arc-shaped groove, a sliding assembly is arranged on the back of the connecting bracket, a limiting block is rotatably connected to the surface of the sliding assembly, a connecting assembly is arranged on the surface of the sliding assembly, and the arc-shaped groove is used to prevent the installation bracket from sliding along the card slot.

[0008] Preferably, the sliding assembly includes a sliding frame, the sliding frame is snap-connected to the installation bracket, a sliding groove is opened on the surface of the sliding frame, the inside of the sliding frame is in contact with the surface of the fixing bracket, and the convex column penetrates through the sliding groove, and the diameter of the convex column is the same as the width of the sliding groove. Connecting rod one and connecting rod two are fixedly connected to the surface of the sliding frame, and the sliding frame slides along the convex column through the opened sliding groove.

[0009] Preferably, the limiting block is sleeved on the outer surface of the convex column and is rotatably connected to the convex column. A counterweight block is embedded in the limiting block. An arc edge one is opened on the surface of the limiting block, and the arc edge one is adapted to the shape of the connecting rod one. Arc edge two and arc edge three are opened on the surface of the limiting block, and the arc edge two and arc edge three are adapted to the shape of the connecting rod two. The limiting bracket is arranged above the right of the convex column to shift the center of gravity of the limiting block to the right.

[0010] Preferably, a limiting groove is opened on the surface of the limiting block, a limiting rod is placed inside the limiting groove, a plug rod is fixedly inserted into the inner wall of the limiting rod, a groove is opened in the convex column, a spring is fixedly connected to the inner wall of the groove, and the spring is fixedly connected to the outer surface of the plug rod. The spring is located inside the sliding groove, and the limiting rod is used to pull the spring to deform through the plug rod.

[0011] Preferably, an arc edge four is opened on the surface of the limiting block, the arc edge four does not contact the connecting rod one, and the arc edge four is adapted to the shape of the arc edge four. After the arc edge four deflects, it gradually contacts the limiting rod until the limiting rod is stuck into the arc edge four.

[0012] Preferably, the connecting assembly includes two groups of brackets, and the ends of the two groups of brackets away from each other are fixedly connected with a convex plate, the two groups of brackets are respectively in contact with the surface of the sliding frame, the front sides of the two groups of convex plates are rotatably connected with threaded rods through a rotating shaft, the ends of the two groups of threaded rods away from the two groups of convex plates respectively penetrate the two groups of connecting frames, the outer surfaces of the two groups of threaded rods are threadedly connected with threaded sleeves, the two groups of threaded sleeves are respectively in contact with the two groups of connecting frames, and the threaded rods are supported by the threaded sleeves.

[0013] Preferably, the two groups of card frames are respectively movably connected with plug plates, and the backs of the two groups of plug plates are rotatably connected with rotating columns through rotating shafts. The ends of the two groups of rotating columns away from the two groups of plug plates are respectively fixedly connected with limiting plates, and the two groups of limiting plates are in contact with the back of the mounting frame. By inserting the plug plates, the card frame and the mounting frame are fixed.

[0014] Compared with the prior art, the present invention provides a power box for electric power engineering that is easy to maintain and has the following beneficial effects: 1. The present invention provides side panels. When it is necessary to inspect the electronic components inside the power box, the side panels can be easily removed and the frame of the box can be completely exposed. At the same time, the mounting frame can slide along the limit frame and move to the middle position of the box, providing more operating space for maintenance personnel, facilitating the inspection and treatment of the internal electronic components. In addition, the maintenance personnel can also rotate the box and flexibly adjust the viewing angle to better expose the electronic components on the mounting frame, thereby improving the inspection efficiency and quality.

[0015] 2. The present invention sets a sliding frame. When the limit block is rotated, the limit rod will be squeezed and gradually disengaged from the limit groove. With the continuous rotation of the limit block, the limit rod will eventually get stuck in the four sides of the arc edge, so that the connecting rod 1 and the connecting rod 2 are no longer restricted in the positive and reverse positions. The sliding frame can drive the mounting frame to move inward until it reaches the middle of the box body smoothly, thereby realizing the flexible displacement of the mounting frame and providing convenience for the adjustment and maintenance of the internal structure of the power box.

[0016] 3. The present invention sets a limit rod. Before the limit block rotates, the spring can clamp the limit rod in the limit groove by its own elastic force. After the limit block rotates, the spring can help the limit rod to be clamped at the four edges of the arc, so that the limit rod effectively limits the limit block.

[0017] 4. The present invention provides a clamping bracket. After the threaded rod is firmly fixed by a threaded sleeve, the limiting plate is rotated to make it in close contact with the back of the mounting bracket, thereby firmly connecting the clamping bracket and the mounting bracket, ensuring that the mounting bracket can remain stable when facing external force, avoiding damage to the electronic components installed thereon due to deviation, and ensuring the normal operation and service life of the electronic components in the power box. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the present invention; Figure 2 It is a schematic structural diagram of the present invention removing the door part; Figure 3 It is a schematic view of the internal structure of the box body of the present invention; Figure 4 It is a perspective view of the fixing frame of the present invention; Figure 5 It is a perspective view of the connecting frame, sliding assembly and connecting assembly of the present invention; Figure 6 It is a schematic structural diagram of the connecting assembly of the present invention; Figure 7 It is a schematic structural diagram of the sliding assembly of the present invention; Figure 8 It is a motion state diagram of the limiting block of the present invention; Figure 9 It is a side view of the limiting block of the present invention; Figure 10 For the present invention Figure 9 An enlarged schematic diagram of A in it.

[0019] In the figure: 1. Box body; 2. Bottom plate; 3. Door; 4. Side plate; 5. Circular plate; 6. Heat dissipation fan group; 7. Partition board; 8. Fixing frame; 81. Limiting frame; 82. Snap ring; 83. Connecting frame; 84. Arc-shaped groove; 85. Card slot; 86. Convex column; 87. Sliding assembly; 871. Sliding frame; 872. Sliding groove; 873. Connecting rod one; 874. Connecting rod two; 88. Limiting block; 881. Counterweight block; 882. First arc edge; 883. Second arc edge; 884. Third arc edge; 885. Limiting groove; 886. Limiting rod; 887. Spring; 888. Plug rod; 889. Fourth arc edge; 89. Connecting assembly; 891. Card frame; 892. Convex plate; 893. Threaded rod; 894. Threaded sleeve; 895. Plug plate; 896. Rotating column; 897. Limiting plate; 9. Mounting frame. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0021] Examples of the described embodiments are shown in the accompanying drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as a limitation to the present invention.

[0022] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] Embodiment 1. Please refer to Figures 1-5 , the present invention provides a technical solution: a power box for a power project that is convenient for maintenance, including a box body 1 and a bottom plate 2. The bottom of the box body 1 is rotatably connected to the bottom plate 2 through a rotating shaft. A box door 3 is hinged to the front of the box body 1 through a hinge. Side plates 4 are connected to the sides and back of the box body 1 by threaded bolts. A circular plate 5 is rotatably connected to the inner wall of the box body 1 through a bearing. A heat dissipation fan group 6 is fixedly connected to the bottom of the inner wall of the box body 1. A partition 7 is arranged above the heat dissipation fan group 6, and the partition 7 is fixedly connected to the inner wall of the box body 1. It further includes: A fixing frame 8. The top of the fixing frame 8 is fixedly connected to the circular plate 5. The bottom of the fixing frame 8 contacts the top of the partition 7. A card slot 85 is formed on the back of the fixing frame 8. An installation frame 9 is arranged on the back of the fixing frame 8. The fixing frame 8 is slidably connected to the installation frame 9 through the card slot 85. A limiting frame 81 is fixedly connected to the inner wall of the fixing frame 8. Both ends of the limiting frame 81 penetrate through the installation frame 9 and are movably inserted into the installation frame 9. Two groups of clamping rings 82 are fixedly connected to the outer surface of the limiting frame 81. The top of the circular plate 5 is fixedly connected to an existing installation fixing frame to provide support for the circular plate 5. Connecting frames 83 are fixedly connected to both the left and right ends of the fixing frame 8. An arc-shaped groove 84 is formed in the middle of the connecting frame 83. Convex columns 86 are fixedly connected to both the left and right ends of the arc-shaped groove 84. A sliding component 87 is arranged on the back of the connecting frame 83. A limiting block 88 is rotatably connected to the surface of the sliding component 87. A connecting component 89 is arranged on the surface of the sliding component 87. The arc-shaped groove 84 is used to prevent the installation frame 9 from being affected when sliding along the card slot 85. When the power box is under maintenance, after the side plate 4 is removed, the frame of the box body 1 is exposed. Among them, on the premise that the installation frame 9 is not restricted, the installation frame 9 slides along the limiting frame 81 until it contacts the clamping ring 82, and the installation frame 9 is moved to the middle of the box body 1, so as to facilitate the maintenance of the electronic components inside the power box. At the same time, the box body 1 can be rotated by rotating the box body 1 to better expose the electronic components installed on the installation frame 9.

[0024] Embodiment 2. On the basis of Embodiment 1, please refer to Figures 7-10, the present invention provides a technical solution: The sliding assembly 87 includes a sliding frame 871, the sliding frame 871 is snap-connected to the mounting frame 9, a sliding groove 872 is formed on the surface of the sliding frame 871, the inside of the sliding frame 871 is in contact with the surface of the fixed frame 8, and the convex column 86 penetrates through the sliding groove 872, and the diameter of the convex column 86 is the same as the width of the sliding groove 872. A first connecting rod 873 and a second connecting rod 874 are fixedly connected to the surface of the sliding frame 871. The sliding frame 871 slides along the convex column 86 through the formed sliding groove 872. The limiting block 88 is sleeved on the outer surface of the convex column 86 and is rotatably connected to the convex column 86. A counterweight block 881 is embedded in the limiting block 88. An arc edge 882 is formed on the surface of the limiting block 88, and the arc edge 882 is adapted to the shape of the first connecting rod 873. Arc edges 883 and 884 are formed on the surface of the limiting block 88, and the arc edges 883 and 884 are adapted to the shape of the second connecting rod 874. The limiting frame 81 is arranged above the right of the convex column 86 and is used to shift the center of gravity of the limiting block 88 to the right. A limiting groove 885 is formed on the surface of the limiting block 88, a limiting rod 886 is placed inside the limiting groove 885, a plug rod 888 is fixedly inserted into the inner wall of the limiting rod 886, a groove 861 is formed inside the convex column 86, a spring 887 is fixedly connected to the inner wall of the groove 861, the spring 887 is fixedly connected to the outer surface of the plug rod 888, and the spring 887 is located inside the sliding groove 872. The limiting rod 886 is used to pull the spring 887 to deform through the plug rod 888. In the normal use state, the second connecting rod 874 connected to the surface of the sliding frame 871 is blocked by the limiting block 88, and the sliding frame 871 cannot drive the mounting frame 9 to move. When the applied forward and reverse forces gradually increase, or when the limiting block 88 is manually rotated counterclockwise, the limiting rod 886 is gradually squeezed out of the limiting groove 885. Among them, after the limiting rod 886 breaks away from the limiting groove 885, it passes through the arc edge 884. After the arc edge 884 is driven by the limiting block 88 to rotate, it gradually approaches the second connecting rod 874 and fits with the second connecting rod 874. Among them, the limiting rod 886 is exactly located at the arc edge 889. At this time, the positions of the first connecting rod 873 and the second connecting rod 874 in the forward and reverse directions are not restricted. That is, the sliding frame 871 can drive the mounting frame 9 to move inward under the limitation of the sliding groove 872 and the convex column 86, so as to drive the mounting frame 9 to move to the middle of the box body 1.

[0025] The surface of the limit block 88 is provided with an arc-edge four 889. The arc-edge four 889 does not contact the first connecting rod 873. The arc-edge four 889 is adapted to the shape of the arc-edge four 889. After the arc-edge four 889 deflects, it gradually contacts the limit rod 886 until the limit rod 886 is snapped into the arc-edge four 889. When the limit rod 886 is squeezed, the limit rod 886 pulls the spring 887 through the insertion rod 888 to cause the spring 887 to deform and elongate. After the limit rod 886 is snapped into the interior of the arc-edge four 889, under the action of the self-restoring force of the spring 887, and then through the restriction of the arc-edge three 884 by the second connecting rod 874, the limit block 88 will no longer rotate counterclockwise, thereby limiting the limit block 88. In this way, during the process of the second connecting rod 874 disengaging from the arc-edge three 884, the limit block 88 will not easily rotate counterclockwise; After the maintenance is completed, the sliding frame 871 drives the second connecting rod 874 to reset and continue to fit the arc-edge three 884. At this time, manually separate the arc-edge one 882 from the arc-edge four 889, and then rotate the limit block 88 clockwise, so that the limit rod 886 can be snapped into the limit groove 885 again to restrict the sliding frame 871 again.

[0026] Embodiment 3, on the basis of Embodiment 1 and Embodiment 2, please refer to Figure 6 , the present invention provides a technical solution: The connection assembly 89 includes two sets of card frames 891. One end of each of the two sets of card frames 891 that are away from each other is fixedly connected with a convex plate 892. The two sets of card frames 891 are respectively in contact with the surface of the sliding frame 871. The front surfaces of the two sets of convex plates 892 are rotatably connected with a threaded rod 893 through a rotating shaft. One end of each of the two sets of threaded rods 893 that are away from the two sets of convex plates 892 respectively penetrates through the two sets of connecting frames 83. Threaded sleeves 894 are threadedly connected to the outer surfaces of the two sets of threaded rods 893. The two sets of threaded sleeves 894 are respectively in contact with the two sets of connecting frames 83 to support the threaded rods 893 through the threaded sleeves 894. Insertion plates 895 are respectively movably inserted into the two sets of card frames 891. The backs of the two sets of insertion plates 895 are rotatably connected with rotating columns 896 through rotating shafts. One end of each of the two sets of rotating columns 896 that are away from the two sets of insertion plates 895 is fixedly connected with a limit plate 897. The two sets of limit plates 897 are both in contact with the back of the mounting frame 9. By inserting the insertion plates 895, the card frames 891 are fixed to the mounting frame 9. During normal use, the card frames 891 are inserted between the sliding frame 871 and the mounting frame 9, and then the insertion plates 895 are inserted into the card frames 891. The limit plates 897 are rotated through the rotating columns 896 to make the limit plates 897 contact the back of the mounting frame 9, so that the connection between the card frames 891 and the mounting frame 9 can be achieved. When moving the mounting frame 9, the threaded rods 893 and the threaded sleeves 894 will not affect the normal movement of the mounting frame 9 either.

[0027] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A power box for a power project that is convenient for maintenance, comprising a box body (1) and a bottom plate (2). The bottom of the box body (1) is rotatably connected to the bottom plate (2) through a rotating shaft. A box door (3) is hinged to the front of the box body (1) through a hinge. Side plates (4) are connected to the sides and back of the box body (1) by screwing bolts. A circular plate (5) is rotatably connected to the inner wall of the box body (1) through a bearing. A heat dissipation fan group (6) is fixedly connected to the bottom of the inner wall of the box body (1). A partition plate (7) is arranged above the heat dissipation fan group (6), and the partition plate (7) is fixedly connected to the inner wall of the box body (1). It is characterized in that, Further included are: A fixing frame (8), the top of the fixing frame (8) is fixedly connected to the circular plate (5), the bottom of the fixing frame (8) is in contact with the top of the partition plate (7), a card slot (85) is formed in the back of the fixing frame (8), an installation frame (9) is arranged on the back of the fixing frame (8), the fixing frame (8) is slidably connected to the installation frame (9) through the card slot (85), a limiting frame (81) is fixedly connected to the inner wall of the fixing frame (8), both ends of the limiting frame (81) penetrate through the installation frame (9) and are movably inserted into the installation frame (9), two groups of clamping rings (82) are fixedly connected to the outer surface of the limiting frame (81), the top of the circular plate (5) is fixedly connected to an existing installation fixing frame to provide support for the circular plate (5).

2. The power box of a power project that is convenient for maintenance according to claim 1, wherein: Connection frames (83) are fixedly connected to both the left and right ends of the fixing frame (8), an arc-shaped groove (84) is formed in the middle of the connection frame (83), convex columns (86) are fixedly connected to both the left and right ends of the arc-shaped groove (84), a sliding component (87) is arranged on the back of the connection frame (83), a limiting block (88) is rotatably connected to the surface of the sliding component (87), a connection component (89) is arranged on the surface of the sliding component (87), and the arc-shaped groove (84) is used to prevent the installation frame (9) from sliding along the card slot (85) from being affected.

3. The power box for a power project that is convenient for maintenance according to claim 2, wherein: The sliding component (87) includes a sliding frame (871), the sliding frame (871) is clamped and connected to the installation frame (9), a sliding groove (872) is formed in the surface of the sliding frame (871), the inside of the sliding frame (871) is in contact with the surface of the fixing frame (8), and the convex column (86) penetrates through the sliding groove (872), and the diameter of the convex column (86) is the same as the width of the sliding groove (872), a connecting rod one (873) and a connecting rod two (874) are fixedly connected to the surface of the sliding frame (871), and the sliding frame (871) slides along the convex column (86) through the formed sliding groove (872).

4. The power box of a power project that is convenient for maintenance according to claim 3, characterized in that: The limiting block (88) is sleeved on the outer surface of the convex column (86) and is rotatably connected to the convex column (86), a counterweight block (881) is embedded in the limiting block (88), an arc edge one (882) is formed in the surface of the limiting block (88), the arc edge one (882) is adapted to the shape of the connecting rod one (873), arc edges two (883) and three (884) are formed in the surface of the limiting block (88), the arc edges two (883) and three (884) are adapted to the shape of the connecting rod two (874), and the limiting frame (81) is arranged above the right of the convex column (86) to shift the center of gravity of the limiting block (88) to the right.

5. The power box of a power project that is convenient for maintenance according to claim 4, wherein: The surface of the limit block (88) is provided with a limit groove (885). A limit rod (886) is placed inside the limit groove (885). A plug rod (888) is fixedly inserted into the inner wall of the limit rod (886). A groove (861) is formed inside the convex column (86). A spring (887) is fixedly connected to the inner wall of the groove (861). The spring (887) is fixedly connected to the outer surface of the plug rod (888). The spring (887) is located inside the sliding groove (872). The limit rod (886) is used to pull the spring (887) through the plug rod (888) to deform.

6. The power box of a power project that is convenient for maintenance according to claim 5, characterized in that: An arc four (889) is formed on the surface of the limit block (88). The arc four (889) does not contact the connecting rod one (873). The arc four (889) is adapted to the arc four (889) in shape. After the arc four (889) deflects, it gradually contacts the limit rod (886) until the limit rod (886) is clamped into the arc four (889).

7. The power box of a power project that is convenient for maintenance according to claim 3, wherein: The connection assembly (89) includes two sets of card racks (891). Convex plates (892) are fixedly connected to the mutually remote ends of the two sets of card racks (891). The two sets of card racks (891) are respectively in contact with the surface of the sliding frame (871). A threaded rod (893) is rotatably connected to the front surfaces of the two sets of convex plates (892) through a rotating shaft. The ends of the two sets of threaded rods (893) remote from the two sets of convex plates (892) respectively penetrate through the two sets of connecting frames (83). Threaded sleeves (894) are threadedly connected to the outer surfaces of the two sets of threaded rods (893). The two sets of threaded sleeves (894) are respectively in contact with the two sets of connecting frames (83). The threaded sleeves (894) are used to support the threaded rods (893).

8. The power box of a power project that is convenient for maintenance according to claim 7, characterized in that: Two sets of plug plates (895) are respectively movably inserted into the two sets of card racks (891). Rotating columns (896) are rotatably connected to the backs of the two sets of plug plates (895) through rotating shafts. Limit plates (897) are fixedly connected to the ends of the two sets of rotating columns (896) remote from the two sets of plug plates (895). The two sets of limit plates (897) are respectively in contact with the back of the mounting frame (9). By inserting the plug plates (895), the card racks (891) are fixed to the mounting frame (9).

Images