A non-adjustable integral dropper maker for railway power supply catenary

Abstract

The application discloses a kind of railway power supply catenary non-adjustable integral pendant maker, including main frame, vice frame, vice frame includes telescopic frame, vice frame work section, telescopic frame slidingly covers in main frame, one end of main frame and vice frame work section is equipped with pull line column respectively, the side of main frame is also equipped with wire cutting pliers, locking positioning device is also equipped between main frame and vice frame, the upper surface of telescopic frame is equipped with mark, the upper surface of main frame is equipped with main frame scale, the minimum distance of pull line column on main frame and vice frame is 100cm, the length range of scale is 100cm-180cm, the minimum size end of scale is located at the junction of moving frame and telescopic frame, the end of minimum size end of main frame scale corresponds with the center of pull line column on main frame, second pull line column is also respectively equipped on main frame and moving frame, two A-shaped supporting legs are formed on the two sides of the bottom of main frame.The application improves the accuracy of production, work efficiency, and the application has the advantages of simple structure, light weight, convenient to carry, strong practicality.

Description

Technical Field

[0001] This invention relates to auxiliary devices for railway equipment manufacturing, and more specifically, to a non-adjustable integral dropper wire maker for railway power supply contact networks. Background Technology

[0002] The overhead contact system (or catenary) is a high-voltage power transmission line erected in a zigzag pattern above the rails in electrified railways to supply current to pantographs. It is a special type of power transmission line that supplies power to electric locomotives. Typically, the catenary consists of a chain suspension, support devices, positioning devices, supports, and foundations. The chain suspension includes the contact wire, droppers, catenary wire, connecting parts, and insulators. A type of non-adjustable integral dropper is commonly used in high-speed electrified railway sections. This type mainly consists of the main dropper wire, upper dropper wire, lower dropper wire, heart-shaped guard rings, and terminals at the ends of the upper and lower dropper wires. The heart-shaped guard rings are connected between the catenary wire and the contact wire via separate dropper wire clamps. The contact wire is suspended from the catenary wire by the non-adjustable droppers, increasing the suspension points for the contact wire at each span without adding supports. This improves the tension and elasticity of the contact wire, enhancing its working quality.

[0003] Existing non-adjustable integral suspenders are usually made manually based on experience without equipment assistance. The finished suspenders have large dimensional errors, resulting in uneven tension and elasticity of the contact wire during use. At the same time, manual production is inefficient and cannot meet the requirements of mass production. Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and provides an implementation method for a non-adjustable integral dropper wire fabrication device for railway power supply contact networks, which is expected to solve the problems of large dimensional errors and low work efficiency in the existing manual fabrication of non-adjustable integral dropper wires.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A non-adjustable integral dropper fabricator for railway power supply contact network includes a main frame and a secondary frame. One end of the main frame has an opening, and a portion of the secondary frame is slidably fitted inside the main frame through the opening end of the main frame. Pull-wire posts are respectively provided on the upper surfaces of the far ends of the main frame and the secondary frame. A wire cutter is also provided on one side of the main frame. A locking and positioning device is also provided between the main frame and the secondary frame. The bottom of the main frame is provided with support legs.

[0007] Optionally, the sub-frame includes a telescopic frame and a sub-frame working section. One end of the sub-frame working section is fixedly connected to the telescopic frame. The telescopic frame is slidably fitted inside the main frame. The guy wire post is set on the sub-frame working section. The cross-sectional dimensions of the sub-frame working section are equal to those of the main frame. A push-pull handle is also connected to the end of the sub-frame working section.

[0008] Optionally, the minimum distance between the guy wire posts on the main frame and the sub-frame is 100cm. The upper surface of the telescopic frame is provided with a scale, the length of which ranges from 100cm to 180cm. The smallest end of the scale is located at the connection between the working section of the sub-frame and the telescopic frame. The upper surface of the main frame is provided with a main frame scale, and the end of the smallest end of the main frame scale corresponds to the center of the guy wire post on the main frame.

[0009] Optionally, the upper surface of the main frame opening has a notch, and a Z-shaped position indicator is installed in the notch. The indicating part of the position indicator is a right triangle with its right-angled side parallel to the end face of the main frame. Two position indicators are provided in the notch, with their apex angles facing each other, and the apex angles of the two position indicators have a positional distance corresponding to the scale numbers on the ruler.

[0010] Optionally, the locking and positioning device includes a positioning bolt. The side wall and bottom wall of the main frame near the opening end are respectively provided with positioning bolt mounting holes. Positioning bolts are threaded into the mounting holes. The positioning bolt outside the main frame is also provided with a rotating handle. A friction plate is rotatably connected to the end of the positioning bolt inside the main frame. The friction plate is in contact with the side wall and bottom wall of the telescopic frame.

[0011] Optionally, limiting pads are provided on the four inner walls of the main frame opening end and the four outer walls of the telescopic frame connecting to the main frame. The limiting pads on the inner wall of the main frame are in contact with the outer wall of the telescopic frame, and the limiting pads on the outer wall of the telescopic frame are in contact with the inner wall of the main frame. The limiting pads are rubber pads.

[0012] Optionally, the wire cutter is connected to the side wall of the main frame via a wire cutter bracket. The side wall of the main frame is provided with a plurality of threaded holes evenly distributed. The wire cutter bracket has mounting holes. The wire cutter bracket is fixed to the side wall of the main frame by bolts, and the wire cutter is fixed to the wire cutter bracket by bolts.

[0013] Optionally, the main frame and the sub-frame are also provided with height-increasing plates, and the height-increasing plates are also provided with second guy wire posts, the positions of which correspond to the guy wire posts on the main frame and the sub-frame, respectively.

[0014] Optionally, the main frame has two A-shaped support legs at its bottom, distributed on both sides of the bottom of the main frame. Each support leg has a fixing lug on both sides of its top. The main frame is mounted between the two fixing lugs, which are connected by a locking rod. Optionally, the main frame and sub-frame have several strip-shaped through holes distributed on their surfaces.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: First, it improves the accuracy of manufacturing. The standard error of manufacturing non-adjustable integral dropper wires for contact wires does not exceed ±2mm. In the past, the accuracy of manual manufacturing was often difficult to be within the error range, requiring repeated manual remanufacturing, which was time-consuming, labor-intensive, and material-intensive. By using a non-adjustable integral dropper wire maker to manufacture precisely by fixing and adding a ruler, the accuracy of dropper wire manufacturing is effectively improved.

[0016] Secondly, it effectively improves work efficiency. Previously, manually making a non-adjustable integral suspender required two people, taking an average of two minutes to complete one suspender. When producing suspenders in batches, the short duration and low efficiency of manual work made this a significant improvement. With the non-adjustable integral suspender maker, only one person is needed, completing one suspender in 20 seconds. This advantage is particularly pronounced in the batch production of non-adjustable integral suspenders, greatly increasing work efficiency.

[0017] Third, it is portable and highly practical. The non-adjustable integral suspender maker can be disassembled at will for easy carrying. Weighing only 8kg, it does not require power supply on site, making it more suitable for on-site use, convenient, practical, and reliable. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the main frame structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the subframe structure of the present invention;

[0021] Figure 4 This is a schematic diagram of the support leg structure of the present invention;

[0022] Figure 5 for Figure 1 Enlarged view of section A in the middle;

[0023] Figure 6 This is a schematic diagram illustrating the usage state of the present invention;

[0024] Figure 7 This is a schematic diagram of the overall suspension cable structure of the present invention;

[0025] The following are the components listed in the diagram: 1. Main frame; 2. Sub-frame; 3. Support leg; 4. Telescopic frame; 5. Sub-frame working section; 6. Guy post; 7. Wire cutter bracket; 8. Push-pull handle; 9. Ruler; 10. Position indicator; 11. Positioning bolt; 12. Main frame ruler; 13. Limiting pad; 14. Fixing lug; 15. Locking rod; 16. Second guy post; 17. Heightening plate; 18. Wire cutter; 19. Suspension wire sub-line; 20. Heart-shaped guard ring; 21. Crimping tube; 22. Suspension wire sub-line terminal; 23. Suspension wire main line. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0027] like Figure 1 As shown: A non-adjustable integral dropper wire fabrication device for railway power supply contact networks includes a main frame 1, a secondary frame 2, and support legs 3. (As shown...) Figure 2 , 3 As shown, the main frame 1 is a hollow rectangular tube with an opening at one end. The sub-frame includes a telescopic frame 4 and a sub-frame working section 5. One end of the sub-frame working section 5 is fixedly connected to the telescopic frame 4. The cross-sectional dimensions of the sub-frame working section 5 are equal to those of the main frame 1. One end of the telescopic frame 4 is slidably fitted into the main frame 1 from the opening end of the main frame 1. The cross-sectional dimensions of the telescopic frame 4 are smaller than the internal cavity of the main frame 1, allowing the telescopic frame 4 to be inserted into the internal cavity of the main frame 1 from the opening. The sub-frame working section 5 remains outside the main frame 1, and the telescopic frame 4 can move inside the main frame 1 to achieve the telescopic function. The support leg 3 is connected to the bottom of the main frame 1. The upper surface of the main frame 1 away from the opening and the upper surface of the sub-frame working section 5 are respectively provided with a wire pull post 6. A wire cutter 18 is also provided on one side of the main frame 1. During use, the relative positions of the main frame 1 and the upper pull post 6 of the working section 5 of the sub-frame are changed by pushing and pulling the sub-frame 2, thus determining the length of the main suspension wire 23. The position of the wire cutter 18 and the upper pull post 6 of the main frame 1 are the same length as the lower suspension wire 19. The main frame 1 and the sub-frame 2 are made of perforated steel with several strip-shaped through holes distributed on the surface. The perforation makes the weight lighter and easier to handle.

[0028] When the subframe 2 retracts to its minimum distance within the main frame 1, the minimum working distance of the guy wire posts 6 on both the main frame 1 and the subframe 2 is 100cm; the upper surface of the telescopic frame 4 is provided with a scale groove, which is set along the telescopic direction of the telescopic frame 4, such as... Figure 5 As shown, a ruler 9 is embedded or pasted into the ruler groove. The ruler 9 is a common steel or plastic ruler for measuring length. The depth of the ruler groove is equal to the thickness of the ruler 9 to prevent the upper surface of the ruler 9 from exceeding the upper surface of the telescopic frame 4. The length range of the ruler 9 is 100cm-180cm. The smallest dimension end of the ruler 9 (i.e., the 0mm end) is located at the connection between the working section 5 of the sub-frame and the telescopic frame 4. When the sub-frame 2 is stretched to its maximum distance within the main frame 1, the maximum working distance of the pull posts 6 on the main frame 1 and the sub-frame 2 is 180cm. This distance can be adjusted during the production of the integral suspension cable; this is just one embodiment. Figure 3 As shown, the end of the working section 5 of the subframe is also connected to a push-pull handle 8. The subframe 2 can be extended and retracted by pulling the push-pull handle 8, making the extension and retraction of the subframe 2 easier.

[0029] The open end of the main frame 1 has a notch on its upper surface, such as Figure 5 As shown, a position indicator 10 is installed in the notch. The position indicator 10 is a Z-shaped steel plate. The indicating part of the position indicator 10 is a right triangle with its right-angled side parallel to the end face of the main frame 1. There are two position indicators 10 in the notch, with their apexes facing each other and a certain distance between them. The distance between the apexes of the two position indicators 10 corresponds to the scale numbers on the ruler 9. By cooperating with the ruler 9 on the telescopic frame 4, the telescopic distance of the sub-frame 2 is made more accurate, and the distance between the two guy wire posts 6 is made more precise.

[0030] The pull post 6 is cylindrical, with a diameter smaller than the heart-shaped portion of the heart-shaped retaining ring 20. The height of the pull post 6 ensures that the heart-shaped retaining ring 20 stays on top without falling off. Figure 6 , 7 As shown. The heart-shaped retaining ring 20, also called the chicken heart ring, is an important component of the non-adjustable integral dropper. Its outer surface has a wire groove. During the manufacturing process, the heart-shaped retaining ring 20 is placed on one of the pull post 6, and then the metal wire is pressed into the wire groove of the heart-shaped retaining ring 20. The metal wire is then folded in half and locked through the pressure tube 21, thus completing the manufacturing of a dropper ring.

[0031] like Figure 2 The wire cutter 18 is connected to the side wall of the main frame 1 via the wire cutter bracket 7. The side wall of the main frame 1 is evenly provided with multiple threaded holes for mounting the wire cutter bracket. The wire cutter bracket 7 is provided with mounting holes. The wire cutter bracket 7 is fixed to the side wall of the main frame 1 by bolts. The wire cutter 18 is fixed to the wire cutter bracket 7 by bolts. The working end of the wire cutter 18 faces the side of the main frame 1. In actual use, the position of the wire cutter bracket 7 is adjusted according to the length of the drop wire sub-line 19. The adjustment method is to determine the length of the drop wire sub-line 19 and then change the position distance of the wire cutter bracket 7 on the side wall of the main frame 1. The position between the working part of the wire cutter 18 and the upper pull post 6 of the main frame 1 is the length of the drop wire sub-line 19. The upper surface of the main frame 1 is also inlaid or affixed with a main frame ruler 12. The main frame ruler 12 is a common steel or plastic ruler for measuring length. The end of the main frame ruler 12 with the smallest size (i.e., the 0mm end) corresponds to the center of the upper pull post 6 of the main frame 1. The main frame ruler 12 makes it easier to determine the length distance between the wire cutter 18 and the upper pull post 6 of the main frame 1. The wire cutter 18 is fixed with bolts, which makes it easier to disassemble and makes the device easier to transport.

[0032] like Figure 2 A limiting pad 13 is provided on the inner wall of the open end of the main frame 1, and the limiting pad 13 is connected to the four sides of the inner wall of the main frame 1; for example Figure 3Limiting pads 13 are also provided on the four sides of the outer wall of the connection end between the telescopic frame 4 and the main frame 1. The limiting pads 13 provided on the main frame 1 and the telescopic frame 4 respectively ensure that the main frame 1 and the telescopic frame 4 can be fully extended and retracted. The limiting pads 13 are rubber pads. The limiting pads 13 limit the telescopic frame 4 in the up, down, left and right directions. At the same time, the limiting pads 13 of the rubber pads can increase a certain friction during the extension and retraction of the telescopic frame 4, effectively avoiding the collision between the telescopic frame 4 and the main frame 1 caused by excessive force or too fast extension and retraction during use. The rubber pads are used as limiting pads 13 because they have a certain elasticity, which can prevent damage to the outer wall of the telescopic frame 4, the scale 9 and the inner wall of the main frame 1 caused by friction.

[0033] like Figure 2 The main frame 1 has positioning bolt mounting holes on its side wall and bottom wall near the opening end. The positioning bolt mounting holes are threaded through holes. One end of the positioning bolt 11 is threaded to the positioning bolt mounting hole. The positioning bolt 11 on the outside of the main frame 1 also has a rotating handle to facilitate the rotation of the positioning bolt 11. Friction plates are rotatably connected to the end of the positioning bolt 11 inside the main frame 1. The friction plates contact the side wall and bottom wall of the telescopic frame 4 respectively. By rotating the positioning bolt 11, the friction plates on the side wall and bottom wall contact and lock with the side wall and bottom wall of the telescopic frame 4, so that the positional relationship between the main frame 1 and the telescopic frame 4 is fixed.

[0034] like Figure 1 The bottom of the main frame 1 has two legs 3, which are A-shaped and distributed on both sides of the main frame 1; for example Figure 4 The top of the support leg 3 has two fixing ears 14 on each side, so that the top of the support leg forms a U-shape. The main frame 1 is installed between the two fixing ears 14. The two fixing ears 14 limit the left and right sides of the main frame 1. The two fixing ears 14 have fixing holes. The upper and lower surfaces of the main frame 1 are limited by inserting the locking rod 15 into the fixing holes. At the same time, the detachable support leg 3 is convenient for transportation.

[0035] like Figure 6 The main frame 1 and the auxiliary frame working section 5 are each equipped with a second guy wire post 16. The two second guy wire posts 16 correspond to the positions of the guy wire posts 6 on the main frame 1 and the auxiliary frame working section 5, respectively. The two second guy wire posts 16 are connected to the corresponding main frame 1 and auxiliary frame working section 5 through separate extension plates 17. The second guy wire posts 16 allow two workers to work simultaneously or work together.

[0036] Specific operating method: Before use, assemble the main frame 1 and place it on the support leg 3 with the upper surface of the main frame 1 facing upwards. Fix it with the locking rod 15. Push or pull the push-pull handle 8 on one side of the sub-frame 2 to adjust the distance between the two pull posts 6 on the main frame 1 and the sub-frame 2. Determine the positional distance between the two pull posts 6 by observing the position indicator 10, and then determine the length of the main suspension line 23. After the positional distance between the two pull posts 6 is determined, rotate the rotating handle of the positioning bolt 11 on the main frame 1 so that the friction plate at the end of the positioning bolt 11 in the main frame 1 contacts the side wall and bottom wall of the telescopic frame 4, thereby fixing the positional relationship between the telescopic frame 4 and the main frame 1. Then determine the length of the sub-suspended wire 19, connect the wire cutter bracket 7 to the main frame 1, and connect the wire cutter 18 to the wire cutter bracket 7 so that the working part of the wire cutter 18 and the positional length of the pull post 6 on the main frame 1 are equal to the length of the sub-suspended wire 19.

[0037] After completing the above assembly, take a heart-shaped retaining ring 20 and place it on the pull post 6 on one side of the main frame 1. Wrap the free end of the metal wire around the heart-shaped retaining ring 20 and fold it. Pull the starting end of the metal wire to the working part of the wire cutter 18 and straighten it. Thread the crimping tube 21 onto the metal wires on both sides of the heart-shaped retaining ring 20, and fix the metal wire at the folded part of the heart-shaped retaining ring 20 using the crimping tube 21. The starting end of the metal wire is the dropper secondary wire 19, and the other end of the metal wire is the dropper main wire 23. Figure 7 The non-adjustable integral dropper end is fabricated by crimping the dropper sub-wire terminal 22 onto the end of the dropper sub-wire 19 with crimping pliers. The completed integral dropper end is then removed, and the heart-shaped retaining ring 20 is fitted onto the guy post 6 on one side of the subframe working section 5. A new heart-shaped retaining ring 20 is then fitted onto the guy post 6 on one side of the main frame 1. The end of the dropper main wire 23 is folded around the heart-shaped retaining ring 20. Another crimping tube 21 is then threaded through the dropper main wire 23 on both sides of the heart-shaped retaining ring 20 and onto the ends of the dropper main wire 23. The main suspension wire 23 and its ends are fixed at the fold of the heart-shaped guard ring 20 by the crimping tube 21. The main suspension wire 23 is between the two pull posts 6, and its tail wire is the new auxiliary suspension wire 19. The free end of the auxiliary suspension wire 19 is pulled to the working part of the wire cutter 18 and straightened. The wire cutter 18 cuts off the excess tail wire, and the length of the auxiliary suspension wire 19 is determined. The auxiliary suspension wire terminal 22 is crimped onto the end of the auxiliary suspension wire 19 by crimping pliers. A complete non-adjustable integral suspension wire is then made.

[0038] In practical use, the length of the main suspension wire 23 can be determined by the second pull post 16, and the length of the auxiliary suspension wire 19 can be determined by the wire cutters 18 on the pull post 6, thereby speeding up the process of making the overall suspension wire.

[0039] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A non-adjustable integral dropper wire fabrication device for railway power supply contact networks, characterized in that: The system includes a main frame (1) and a secondary frame (2). One end of the main frame (1) has an opening. A portion of the secondary frame (2) is slidably fitted inside the main frame (1) through the opening end of the main frame (1). A pull post (6) is provided on the upper surface of the main frame (1) away from the opening end and on the upper surface of the secondary frame (2) respectively. A wire cutter (18) is also provided on one side of the main frame (1). A locking and positioning device is also provided between the main frame (1) and the secondary frame (2). The bottom of the main frame (1) is provided with a support leg (3). The secondary frame (2) includes a telescopic frame (4) and a secondary frame working section (5). One end of the secondary frame working section (5) is connected to the telescopic frame. The telescopic frame (4) is fixedly connected, and the telescopic frame (4) is slidably sleeved inside the main frame (1). The pull post (6) on the sub-frame (2) is set on the working section (5) of the sub-frame. The end of the working section (5) of the sub-frame is also connected to a push-pull handle (8). The upper surface of the telescopic frame (4) is provided with a scale (9), and the smallest size end of the scale (9) is located at the connection between the working section (5) of the sub-frame and the telescopic frame (4). The upper surface of the main frame (1) is provided with a main frame scale (12), and the end of the smallest size end of the main frame scale (12) is located at the center of the pull post (6) on the main frame (1). Locking and positioning device Including a positioning bolt (11), a friction plate is rotatably connected to the end of the positioning bolt (11) inside the main frame (1), and the friction plate contacts the side wall and bottom wall of the telescopic frame (4); limiting pads (13) are respectively provided on the four inner walls of the open end of the main frame (1) and on the four outer walls of the connection end between the telescopic frame (4) and the main frame (1), the limiting pads (13) on the inner wall of the main frame (1) contact the outer wall of the telescopic frame (4), and the limiting pads (13) on the outer wall of the telescopic frame (4) contact the inner wall of the main frame (1); the wire cutter (18) is connected to the wire cutter bracket (7). It is connected to the side wall of the main frame (1); the main frame (1) and the sub-frame (2) are also equipped with heightening plates (17), and the heightening plates (17) are also equipped with second pull posts (16). The second pull posts (16) correspond to the positions of the pull posts (6) on the main frame (1) and the sub-frame (2). When in use, the relative position of the pull posts (6) on the main frame (1) and the working section (5) of the sub-frame is changed by pushing and pulling the sub-frame (2) to determine the length of the main line (23) of the suspension wire. The position of the wire cutter (18) and the pull post (6) on the main frame (1) is the same as the length of the sub-line (19) of the suspension wire.

2. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The upper surface of the opening end of the main frame (1) has a notch, and a Z-shaped position indicator (10) is installed in the notch. The indicating part of the position indicator (10) is a right triangle with its right-angled side parallel to the end face of the main frame (1). Two position indicators (10) are provided in the notch, with the apex angles of the two position indicators (10) facing each other, and the apex angles of the two position indicators (10) have a positional distance corresponding to the scale number on the ruler (9).

3. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The main frame (1) has positioning bolt mounting holes on the side wall and bottom wall near the opening end, and the positioning bolts (11) are threaded into the positioning bolt mounting holes. The positioning bolts (11) on the outside of the main frame (1) also have rotating handles.

4. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The limiting pad (13) is a rubber pad.

5. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The main frame (1) has a plurality of threaded holes evenly provided on its side wall, and the wire cutter bracket (7) has corresponding mounting holes. The wire cutter bracket (7) is fixed to the side wall of the main frame (1) by bolts, and the wire cutter (18) is fixed to the wire cutter bracket (7) by bolts.

6. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The main frame (1) has two legs (3) at the bottom. The legs (3) are A-shaped and distributed on both sides of the bottom of the main frame (1). The top of the legs (3) has two fixing ears (14) on each side. The main frame (1) is installed between the two fixing ears (14) and the two fixing ears (14) are connected by a locking rod (15).

7. The non-adjustable integral dropper wire fabricator for railway power supply contact network according to claim 1, characterized in that: The main frame (1) and the sub-frame (2) have several strip-shaped through holes distributed on their surfaces.

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