Automatic positioning device for medium frequency heating belt

Abstract

The utility model relates to pipeline welding auxiliary device technical field, is a kind of automatic in position device of medium-frequency heating band, including medium-frequency heating band and the welding shed covered in the upper portion of medium-frequency heating band, further including winch, first pulley, second pulley, first wire rope and second wire rope, first pulley and second pulley are symmetrically installed in the upper portion left and right interval of medium-frequency heating band, first fixed seat is installed in the inside of the upper portion of welding shed corresponding the position above first pulley, first guide pulley is rotatably installed in first fixed seat.The utility model is reasonable and compact, the quick lifting and positioning of medium-frequency heating band are realized by the start-stop of winch control, the medium-frequency heating band can be evenly wrapped on the outside of pipeline, the pipeline is heated, and it can be completed by single operation, the efficiency is improved by 3 to 5 times compared with manual winding mode, and falling injury accident and scald accident easily caused under high temperature environment during manual operation can also be avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of auxiliary devices for pipeline welding, and is an automatic positioning device for medium-frequency heating belts. Background Technology

[0002] Currently, the demand for medium-frequency heating technology in the pipeline welding field is continuously increasing. Traditional medium-frequency heating belt operation relies on manual placement, positioning, and heating, which has the following drawbacks: First, the contradiction between efficiency and cost is prominent. Taking oil and gas pipeline welding as an example, a single heating operation requires two workers to work together to move the heavy medium-frequency heating belt onto the pipeline, which is time-consuming and labor-intensive. Manual operation drags down the overall production line efficiency. According to the "2023 China Welding Equipment Industry Report," labor costs already account for more than 35% of the total cost of the heating process, with an average annual growth rate exceeding 12%. Second, precision and safety risks coexist. Manual placement of the medium-frequency heating belt is prone to errors due to visual bias. Uneven contact between the frequency heating belt and the pipeline can easily lead to localized overheating or underheating. In addition, manual operation in high-temperature environments can easily cause safety accidents; in 2022 alone, 127 burn accidents were reported in China. Third, the demand for flexible production is gradually increasing, and the rise of industries such as new energy and semiconductors is driving the diversification of pipeline specifications (ranging from 1016mm to 1422mm in diameter). Traditional medium-frequency heating belts require frequent replacement and adjustment, and the debugging process is time-consuming and wasteful. While advanced foreign companies have launched semi-automatic heating equipment, their customized services are expensive, making it difficult for small and medium-sized enterprises to afford. Summary of the Invention

[0003] This utility model provides an automatic positioning device for medium-frequency heating belts, which overcomes the shortcomings of the prior art. It can effectively solve the problems of the risk of falling during the placement of existing medium-frequency heating belts and the risk of burns caused by high-temperature environments.

[0004] The technical solution of this utility model is achieved through the following measures: an automatic positioning device for a medium-frequency heating belt, including a medium-frequency heating belt and a welding canopy covering the medium-frequency heating belt, and also including a winch, a first pulley, a second pulley, a first wire rope, and a second wire rope. The first pulley and the second pulley are symmetrically installed on the upper part of the medium-frequency heating belt at left and right intervals. A first fixed seat is installed on the inner side of the upper part of the welding canopy corresponding to the position above the first pulley. A first guide pulley is rotatably installed in the first fixed seat. A second fixed seat is installed on the inner side of the upper part of the welding canopy corresponding to the position above the second pulley. A second guide pulley is rotatably installed in the second fixed seat. A winch is installed on the upper part of the welding canopy. The first end of the first wire rope is fixedly connected to the first fixed seat. The second end of the first wire rope passes sequentially around the lower outer side of the first pulley and the left outer side of the first guide pulley before being fixedly connected to the outer side of the output shaft of the winch. The first end of the second wire rope is fixedly connected to the second fixed seat. The second end of the second wire rope passes sequentially around the lower outer side of the second pulley and the left outer side of the second guide pulley before being fixedly connected to the outer side of the output shaft of the winch.

[0005] The following are further optimizations and / or improvements to the above-mentioned utility model technical solution: A first lifting ring can be fixedly installed on the left side of the intermediate frequency heating belt corresponding to the left position of the first pulley. A third fixing seat is fixedly installed on the inner side of the left side of the welding shed corresponding to the lower left position of the first guide pulley. A third guide pulley is rotatably installed inside the third fixing seat. A third steel wire rope is connected between the first lifting ring and the outer side of the output shaft of the winch. The middle part of the third steel wire rope is in contact with the outer side of the left side of the third guide pulley. A second lifting ring is fixedly installed on the right side of the intermediate frequency heating belt corresponding to the right position of the second pulley. A fourth steel wire rope is connected between the second lifting ring and the outer side of the output shaft of the winch.

[0006] The output shaft of the aforementioned winch is sequentially and fixedly mounted with a first winding reel, a second winding reel, a third winding reel, and a fourth winding reel from front to back. The upper end of the third wire rope is fixedly connected to the outer side of the fourth winding reel, and the lower end of the third wire rope is fixedly connected to a first hook, which is connected to a first lifting ring. The second end of the first wire rope is fixedly connected to the outer side of the third winding reel, and the second end of the second wire rope is fixedly connected to the outer side of the second winding reel. The upper end of the fourth wire rope is fixedly connected to the outer side of the first winding reel, and the lower end of the fourth wire rope is fixedly connected to a second hook, which is connected to a second lifting ring.

[0007] The outer side of the first guide pulley is provided with a first rope groove and a second rope groove from front to back. The third wire rope is wound around the inner left side of the second rope groove, and the first wire rope is wound around the inner upper part of the first rope groove.

[0008] The outer side of the second guide pulley is provided with a third rope groove, a fourth rope groove and a fifth rope groove from front to back. The second wire rope is wound around the inner left side of the third rope groove, the first wire rope is wound around the inner upper part of the fourth rope groove, and the third wire rope is wound around the inner upper part of the fifth rope groove.

[0009] The distance between the upper end of the first hook and the central axis of the second rope groove is the same as the distance between the upper end of the second hook and the central axis of the fourth winding disc. The distance between the central axes of the first guide pulley and the second guide pulley and the second pulley is the same.

[0010] This utility model has a reasonable and compact structure. By controlling the start and stop of the winch, the medium-frequency heating belt can be quickly raised, lowered and positioned, which can make the medium-frequency heating belt evenly wrapped around the outside of the pipe, making it easy to heat the pipe. It can be completed by a single person, which is 3 to 5 times more efficient than manual winding. It can also avoid the accidental fall injury caused by manual operation and the accidental burn caused by high temperature environment.

[0011] This application can reduce the preparation process for pipeline heating. The winch can automatically lift and lower the medium-frequency heating belt, improve the positioning speed, eliminate the manual calibration process, reduce human error, avoid the large amount of time wasted due to repeated position adjustments, and shorten the installation cycle. Attached Figure Description

[0012] Appendix Figure 1 This is a schematic diagram of the front cross-sectional structure of Embodiment 1 of this utility model.

[0013] Appendix Figure 2 These are schematic diagrams of the main cross-sectional structure of embodiments two to six of this utility model.

[0014] Appendix Figure 3 This is a left-side structural schematic diagram of the first guide pulley in embodiments two to six of this utility model.

[0015] Appendix Figure 4 This is a left-side structural schematic diagram of the second guide pulley in embodiments two to six of this utility model.

[0016] Appendix Figure 5 This is a left-side structural schematic diagram of the winch in embodiments two to six of this utility model.

[0017] The codes in the attached diagram are as follows: 1 for medium-frequency heating belt, 2 for welding shed, 3 for winch, 4 for first pulley, 5 for second pulley, 6 for first wire rope, 7 for second wire rope, 8 for first fixed seat, 9 for second fixed seat, 10 for first guide pulley, 11 for second guide pulley, 12 for first lifting ring, 13 for third fixed seat, 14 for third guide pulley, 15 for third wire rope, 16 for second lifting ring, 17 for fourth wire rope, 18 for first winding disc, 19 for second winding disc, 20 for third winding disc, 21 for fourth winding disc, 22 for first hook, 23 for second hook, 24 for first rope groove, 25 for second rope groove, 26 for third rope groove, 27 for fourth rope groove, and 28 for fifth rope groove. Detailed Implementation

[0018] This utility model is not limited to the following embodiments, and the specific implementation method can be determined according to the technical solution of this utility model and the actual situation.

[0019] In this utility model, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0020] The present invention will be further described below with reference to the embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 As shown, the automatic positioning device for the intermediate frequency heating belt includes an intermediate frequency heating belt 1 and a welding canopy 2 covering the intermediate frequency heating belt 1. It also includes a winch 3, a first pulley 4, a second pulley 5, a first steel wire rope 6, and a second steel wire rope 7. The first pulley 4 and the second pulley 5 are symmetrically installed at intervals on the upper part of the intermediate frequency heating belt 1. A first fixed seat 8 is installed on the inner side of the upper part of the welding canopy 2 corresponding to the position above the first pulley 4. A first guide pulley 10 is rotatably installed inside the first fixed seat 8. A second fixed seat 9 is installed on the inner side of the upper part of the welding canopy 2 corresponding to the position above the second pulley 5. A second guide pulley 11 is rotatably installed inside the second fixed seat 9. A winch 3 is installed on the upper part of the welding shed 2. The first end of the first wire rope 6 is fixedly connected to the first fixed seat 8. The second end of the first wire rope 6 passes through the lower outer side of the first pulley 4 and the left outer side of the first guide pulley 10 in sequence, and is then fixedly connected to the outer side of the output shaft of the winch 3. The first end of the second wire rope 7 is fixedly connected to the second fixed seat 9. The second end of the second wire rope 7 passes through the lower outer side of the second pulley 5 and the left outer side of the second guide pulley 11 in sequence, and is then fixedly connected to the outer side of the output shaft of the winch 3.

[0021] Depending on the requirements, the winch 3 is a known electric winch or hydraulic winch, and the medium-frequency heating belt 1 and welding shed 2 are both known technologies. During use, the start and stop of the winch 3 are controlled to reel in and unwind the first wire rope 6 and the second wire rope 7, thereby achieving rapid lifting and positioning of the medium-frequency heating belt 1. This allows the medium-frequency heating belt 1 to be evenly wrapped around the outside of the pipe, facilitating pipe heating. This can be completed by a single person, increasing efficiency by 3 to 5 times compared to manual winding. It also avoids falls and burns that can easily occur during manual operation, as well as burns caused by high temperatures.

[0022] This application can reduce the preparation process during pipeline heating. The winch 3 can automatically lift and lower the medium frequency heating belt 1, improve the positioning speed, eliminate the manual calibration process, reduce human error, avoid a lot of time loss due to repeated position adjustments, and shorten the installation cycle.

[0023] The above-mentioned automatic positioning device for medium-frequency heating belts can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown, a first lifting ring 12 is fixedly installed on the left side of the intermediate frequency heating belt 1 corresponding to the left position of the first pulley 4. A third fixed seat 13 is fixedly installed on the inner side of the left side of the welding shed 2 corresponding to the lower left position of the first guide pulley 10. A third guide pulley 14 is rotatably installed inside the third fixed seat 13. A third steel wire rope 15 is connected between the first lifting ring 12 and the outer side of the output shaft of the winch 3. The middle part of the third steel wire rope 15 is in contact with the outer side of the left side of the third guide pulley 14. A second lifting ring 16 is fixedly installed on the right side of the intermediate frequency heating belt 1 corresponding to the right position of the second pulley 5. A fourth steel wire rope 17 is connected between the second lifting ring 16 and the outer side of the output shaft of the winch 3.

[0024] According to requirements, the first lifting ring 12 is located to the lower left of the first pulley 4, and the second lifting ring 16 is located to the lower right of the second pulley 5. The arrangement of the first lifting ring 12 and the second lifting ring 16 facilitates the connection between the third wire rope 15 and the fourth wire rope 17 and the medium-frequency heating belt 1. The arrangement of the third fixed seat 13 facilitates the assembly and disassembly of the third guide pulley 14 and the welding shed 2. This application forms a lifting mechanism by combining multiple pulley groups. The weight is distributed among multiple pulley groups, and the lifting of the medium-frequency heating belt 1 is controlled by the winch 3 and the pulley groups, achieving efficient heating, improving the safety of the medium-frequency heating belt 1 during the heating process, greatly saving the heating time required, completing the heating work faster, saving space, and the multiple pulley groups have the characteristic of saving effort, allowing the use of a lower-power electric winch 3, thereby reducing power consumption and saving electricity. It can be applied to pipes of different diameters, ensuring efficiency while reducing safety hazards.

[0025] Example 3: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown in Figure 5, from front to back, the output shaft of the winch 3 is fixedly installed with a first winding disc 18, a second winding disc 19, a third winding disc 20, and a fourth winding disc 21. The upper end of the third wire rope 15 is fixedly connected to the outside of the fourth winding disc 21, and the lower end of the third wire rope 15 is fixedly connected to a first hook 22, which is connected to a first lifting ring 12. The second end of the first wire rope 6 is fixedly connected to the outside of the third winding disc 20, the second end of the second wire rope 7 is fixedly connected to the outside of the second winding disc 19, the upper end of the fourth wire rope 17 is fixedly connected to the outside of the first winding disc 18, and the lower end of the fourth wire rope 17 is fixedly connected to a second hook 23, which is connected to a second lifting ring 16.

[0026] During use, hooks and lifting rings facilitate the connection between the wire rope and the medium-frequency heating belt 1, making assembly and disassembly simple and convenient, reducing labor intensity. The first wire rope 6, the second wire rope 7, the third wire rope 15, and the fourth wire rope 17 are wound in the same direction on the outside of the third winding disc 20, the second winding disc 19, the fourth winding disc 21, and the first winding disc 18. By setting the first winding disc 18, the second winding disc 19, the third winding disc 20, and the fourth winding disc 21, when the winch 3 is working, the output shaft of the winch 3 can drive the first winding disc 18, the second winding disc 19, the third winding disc 20, and the fourth winding disc 21 to rotate synchronously. This allows the first wire rope 6, the second wire rope 7, the third wire rope 15, and the fourth wire rope 17 to act on the medium-frequency heating belt 1 simultaneously, making the medium-frequency heating belt 1 evenly stressed and avoiding breakage due to concentrated stress, thus reducing the failure rate.

[0027] Example 4: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown in Figure 3, the outer side of the first guide pulley 10 is provided with a first rope groove 24 and a second rope groove 25 at intervals from front to back. The third steel wire rope 15 is wound around the inner side of the left part of the second rope groove 25, and the first steel wire rope 6 is wound around the inner side of the upper part of the first rope groove 24.

[0028] The third wire rope 15 is wound around the inner left side of the second rope groove 25, meaning the length of the third wire rope 15 in contact with the second rope groove 25 is less than the circumference of the second rope groove 25. The first wire rope 6 is wound around the inner upper part of the first rope groove 24, meaning the length of the first wire rope 6 in contact with the first rope groove 24 is less than the circumference of the first rope groove 24. During use, the outer side of the first guide pulley 10 is provided with the first rope groove 24 and the second rope groove 25 spaced apart from front to back, meaning the first guide pulley 10 is a double-groove pulley. This arrangement ensures that both the first wire rope 6 and the third wire rope 15 are in contact with the outer left side of the first guide pulley 10, making the structure of the automatic positioning device for the medium-frequency heating belt more compact and facilitating subsequent welding operations on the pipeline.

[0029] Example 5: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown in Figure 4, the outer side of the second guide pulley 11 is provided with a third rope groove 26, a fourth rope groove 27 and a fifth rope groove 28 spaced from front to back. The second wire rope 7 is wound around the inner left side of the third rope groove 26, the first wire rope 6 is wound around the inner upper part of the fourth rope groove 27, and the third wire rope 15 is wound around the inner upper part of the fifth rope groove 28.

[0030] As required, the fourth rope groove 27 corresponds one-to-one with the first rope groove 24, and the fifth rope groove 28 corresponds one-to-one with the second rope groove 25. This allows the first wire rope 6, the second wire rope 7, and the third wire rope 15 to all be wound around the outside of the second guide pulley 11. The second wire rope 7 is wound around the inner left side of the third rope groove 26, meaning the length of the second wire rope 7 in contact with the third rope groove 26 is less than the circumference of the third rope groove 26. The first wire rope 6 is wound around the inner upper part of the fourth rope groove 27, meaning the first wire rope 6 is in contact with the fourth rope groove 27. The length of the third wire rope 15 is less than the circumference of the fourth rope groove 27. The third wire rope 15 is wound around the upper inner side of the fifth rope groove 28. That is, the length of the third wire rope 15 in contact with the fifth rope groove 28 is less than the circumference of the fifth rope groove 28. This makes the structure of the automatic positioning device of the medium frequency heating belt more compact. It can also avoid the entanglement of the first wire rope 6, the second wire rope 7 and the third wire rope 15 during the tensioning and relaxation process. This allows the medium frequency heating belt 1 to rise or fall quickly, shortening the heating time of the medium frequency heating belt 1 on the pipeline and improving the work efficiency.

[0031] Example 6: As an optimization of the above examples, as shown in the appendix Figure 1 , 2 As shown, the distance between the upper end of the first hook 22 and the central axis of the second rope groove 25 is the same as the distance between the upper end of the second hook 23 and the central axis of the fourth winding disc 21. The distance between the central axis of the first guide pulley 10 and the central axis of the first pulley 4 is the same as the distance between the central axis of the second guide pulley 11 and the central axis of the second pulley 5.

[0032] The distance between the upper end of the first hook 22 and the central axis of the second rope groove 25 is the same as the distance between the upper end of the second hook 23 and the central axis of the fourth winding disc 21. That is, the length L1 of the third wire rope 15 between the upper end of the first hook 22 and the contact point with the inner left wall of the second rope groove 25 (the shortest distance between the contact point of the third wire rope 15 with the second rope groove 25 and the upper end of the first hook 12) and the length L2 of the fourth wire rope 17 fixed between the upper end of the second hook 23 and the contact point with the outer wall of the fourth winding disc 21 (the shortest distance between the contact point of the fourth wire rope 17 with the fourth winding disc 21 and the upper end of the second hook 23) are the same. The shortest distance is the same. According to the requirements, the distance between the upper end of the first hook 22 and the central axis of the second rope groove 25 is twice the distance between the central axis of the first guide pulley 10 and the central axis of the first pulley 4. That is, the length L1 of the third wire rope 15 between the upper end of the first hook 22 and the contact point with the inner left wall of the second rope groove 25 is twice the length L3 (the minimum distance between the contact point of the first wire rope 5 and the contact point of the first pulley 4 and the contact point of the second rope groove 25) between the contact point (upper end) of the first wire rope 6 on the outer left side of the first pulley 4 and the contact point (lower end) of the second rope groove 25.

[0033] During operation, when winch 3 is working, it drives the first winding reel 18, the second winding reel 19, the third winding reel 20, and the fourth winding reel 21 to rotate synchronously, thereby pulling and releasing the first wire rope 6, the second wire rope 7, the third wire rope 15, and the fourth wire rope 17. After the output shaft of winch 3 rotates forward, it drives the first winding reel 18, the second winding reel 19, the third winding reel 20, and the fourth winding reel 21 to rotate synchronously, tightening the first wire rope 6, the second wire rope 7, the third wire rope 15, and the fourth wire rope 17. This allows the intermediate frequency heating belt 1 to be raised. After the intermediate frequency heating belt 1 is lifted, it forms a U-shape with the opening facing downwards. Before the pipe welding heating, after the pipe position is in place, the output shaft of winch 3 reverses and drives the first winding reel 18, the second winding reel 19, the third winding reel 20, and the fourth winding reel 21 to rotate synchronously. The first, second, and third winding discs 19, 20, and 21 rotate synchronously, loosening the first, second, third, and fourth wire ropes 6, 7, 15, and 17. This allows the medium-frequency heating belt 1 to be lowered to the outside of the pipe. Then, the winch 3 stops working. When the medium-frequency heating belt 1 is working, it can heat the pipe. After the pipe heating is completed, the output shaft of the winch 3 rotates forward again, driving the first, second, and third winding discs 18, 19, 20, and 21 to rotate synchronously, tightening the first, second, third, and fourth wire ropes 6, 7, 15, and 17. This allows the medium-frequency heating belt 1 to be raised again, which facilitates the raising and lowering of the medium-frequency heating belt 1 and also facilitates subsequent welding operations on the pipe.

[0034] The above technical features constitute various embodiments of this utility model, which have strong adaptability and optimal implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. An automatic positioning device for a medium-frequency heating belt, comprising a medium-frequency heating belt and a welding canopy covering the medium-frequency heating belt, characterized in that... It also includes a first wire rope and a second wire rope. A first pulley and a second pulley are symmetrically installed at intervals on the upper part of the medium frequency heating belt. A first fixed seat is installed on the inner side of the upper part of the welding shed corresponding to the position above the first pulley. A first guide pulley is rotatably installed in the first fixed seat. A second fixed seat is installed on the inner side of the upper part of the welding shed corresponding to the position above the second pulley. A second guide pulley is rotatably installed in the second fixed seat. A winch is installed on the upper part of the welding shed. The first end of the first wire rope is fixedly connected to the first fixed seat. The second end of the first wire rope passes sequentially around the lower outer side of the first pulley and the left outer side of the first guide pulley before being fixedly connected to the outer side of the output shaft of the winch. The first end of the second wire rope is fixedly connected to the second fixed seat. The second end of the second wire rope passes sequentially around the lower outer side of the second pulley and the left outer side of the second guide pulley before being fixedly connected to the outer side of the output shaft of the winch.

2. The automatic positioning device for medium-frequency heating belt according to claim 1, characterized in that... A first lifting ring is fixedly installed on the left side of the intermediate frequency heating belt corresponding to the left position of the first pulley. A third fixed seat is fixedly installed on the inner side of the left side of the welding shed corresponding to the lower left position of the first guide pulley. A third guide pulley is rotatably installed inside the third fixed seat. A third steel wire rope is connected between the first lifting ring and the outer side of the output shaft of the winch. The middle part of the third steel wire rope is in contact with the outer side of the left side of the third guide pulley. A second lifting ring is fixedly installed on the right side of the intermediate frequency heating belt corresponding to the right position of the second pulley. A fourth steel wire rope is connected between the second lifting ring and the outer side of the output shaft of the winch.

3. The automatic positioning device for medium-frequency heating belt according to claim 2, characterized in that... The output shaft of the winch is fixedly installed with a first winding reel, a second winding reel, a third winding reel, and a fourth winding reel in sequence from front to back. The upper end of the third wire rope is fixedly connected to the outer side of the fourth winding reel, and the lower end of the third wire rope is fixedly connected to a first hook, which is connected to a first lifting ring. The second end of the first wire rope is fixedly connected to the outer side of the third winding reel, and the second end of the second wire rope is fixedly connected to the outer side of the second winding reel. The upper end of the fourth wire rope is fixedly connected to the outer side of the first winding reel, and the lower end of the fourth wire rope is fixedly connected to a second hook, which is connected to a second lifting ring.

4. The automatic positioning device for medium-frequency heating belt according to claim 2 or 3, characterized in that... The outer side of the first guide pulley is provided with a first rope groove and a second rope groove at intervals from front to back. The third wire rope is wound around the inner left side of the second rope groove, and the first wire rope is wound around the inner upper part of the first rope groove.

5. The automatic positioning device for medium-frequency heating belt according to claim 4, characterized in that... The outer side of the second guide pulley is provided with a third rope groove, a fourth rope groove and a fifth rope groove from front to back. The second wire rope is wound around the inner left side of the third rope groove, the first wire rope is wound around the inner upper part of the fourth rope groove, and the third wire rope is wound around the inner upper part of the fifth rope groove.

6. The automatic positioning device for medium-frequency heating belt according to claim 3 or 5, characterized in that... The distance between the upper end of the first hook and the central axis of the second rope groove is the same as the distance between the upper end of the second hook and the central axis of the fourth winding disc. The distance between the central axes of the first guide pulley and the second guide pulley and the second pulley is the same.

7. The automatic positioning device for medium-frequency heating belt according to claim 4, characterized in that... The distance between the upper end of the first hook and the central axis of the second rope groove is the same as the distance between the upper end of the second hook and the central axis of the fourth winding disc. The distance between the central axes of the first guide pulley and the second guide pulley and the second pulley is the same.

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