A car sunshade structure

Abstract

This utility model relates to the field of sunshade technology, and more particularly to a car sunshade structure, including a base, a storage tube, a sunshade device, and a double-disc damper. The storage tube is a hollow structure with an opening on its side. The sunshade device is disposed inside the storage tube and can extend or retract through the opening. The drive disc of the double-disc damper is rotatably connected to the base, and the driven disc of the double-disc damper is connected to the bottom surface of the storage tube. When the drive disc of the double-disc damper rotates, the driven disc of the double-disc damper drives the storage tube to rotate, thereby changing the orientation of the opening. Through this method of changing the opening orientation, the user can manually and flexibly adjust the shading angle of the sunshade device extending from the storage tube through the opening, allowing it to fit closely to the curved surface of the car window and freely extend and retract along the curved surface of the window, thus significantly improving the uniformity and overall performance of the sunshade effect.

Description

Technical Field

[0001] This utility model relates to the field of sunshade technology, and in particular to a car sunshade structure. Background Technology

[0002] With the continuous development of the automotive industry, in-car comfort and riding experience have received increasing attention. To improve the in-car environment and enhance riding comfort, various auxiliary devices are constantly being applied and optimized. As one effective sunshade device, automotive sunshades are widely used on car windows to block sunlight, reduce interior temperature rise, achieve heat insulation, and thus improve the in-car riding experience. Generally, automotive sunshades are mainly made of materials such as fabric, plastic film, and aluminum foil, and are expanded and contracted through rolling or folding to allow users to adjust the shading range according to their needs. However, existing automotive sunshade designs often focus on telescopic structures, lacking flexible shading angle adjustment structures. This makes it difficult for the sunshade to fit tightly against the curved surface of the car window, significantly affecting the uniformity and overall performance of the sunshade effect. Utility Model Content

[0003] In view of this, the present invention proposes a car sunshade structure, which aims to solve the problem that existing car sunshades lack a flexible shading angle adjustment structure.

[0004] This utility model proposes a car sunshade structure, including a base, a storage tube, a sunshade device, and a double-disc damper. The storage tube has a hollow structure and an opening on its side. The sunshade device is disposed inside the storage tube and can extend or retract through the opening. The drive disc of the double-disc damper is rotatably connected to the base, and the driven disc of the double-disc damper is connected to the bottom surface of the storage tube. When the drive disc of the double-disc damper rotates, the driven disc of the double-disc damper drives the storage tube to rotate, thereby changing the orientation of the opening.

[0005] In one possible implementation, both the drive disk and the driven disk of the dual-disc damper are circular and coaxially arranged.

[0006] In one possible implementation, the sunshade device includes a drive motor, a rotating shaft, and a sunshade curtain. The output shaft of the drive motor is connected to the rotating shaft, and the rotating shaft is located inside the storage tube and coaxially arranged with the storage tube. One end of the sunshade curtain is fixedly connected to the rotating shaft, and the sunshade curtain can be rolled up or unfolded around the rotating shaft. When the drive motor drives the rotating shaft to rotate in the forward direction through the output shaft, the sunshade curtain unfolds around the rotating shaft and extends out of the storage tube through the opening. When the drive motor drives the rotating shaft to rotate in the reverse direction through the output shaft, the sunshade curtain rolls up around the rotating shaft and retracts into the storage tube through the opening.

[0007] In one possible implementation, the end of the shaft is recessed towards the center to form a mounting position for mounting the drive motor, which is disposed at the mounting position.

[0008] In one possible implementation, the dual-disc damper includes a first damper rotatably connected to the left end of the base and a second damper rotatably connected to the right end of the base. The first damper and the second damper have identical structures. The left end of the storage tube is connected to the first damper, and the right end of the storage tube is connected to the second damper.

[0009] In one possible implementation, the drive motor includes a first motor located at the left end of the shaft and a second motor located at the right end of the shaft.

[0010] In one possible implementation, the car sunshade structure further includes a first fixed end cap located at the left end of the base and a second fixed end cap located at the right end of the base. The first fixed end cap and the second fixed end cap have the same structure and are respectively connected to the left and right ends of the storage tube. One side of the first fixed end cap is connected to the driven plate of the first damper, and the other side of the first fixed end cap is connected to the first motor. One side of the second fixed end cap is connected to the driven plate of the second damper, and the other side of the second fixed end cap is connected to the second motor.

[0011] In one possible implementation, the sunshade device further includes a plurality of guide ribs, all of which are connected to the sunshade curtain and arranged in a direction perpendicular to the axis of rotation.

[0012] In one possible implementation, the guide ribs include four ribs with identical structures, two of which are located on the left and right sides of the sunshade respectively, and the other two ribs are separately arranged in the central area of ​​the sunshade.

[0013] In one possible implementation, the base is connected to the bottom of the car window, and the guide rib is an elastic steel strip; when the sunshade extends upward through the opening into the storage tube, the elastic steel strip is in a flat state; when the sunshade retracts downward through the opening into the storage tube, the elastic steel strip is in a spiral wound state.

[0014] Compared with existing technologies, the advantages of this utility model are as follows: A car sunshade structure includes a base, a storage tube, a sunshade device, and a double-disc damper. The storage tube is a hollow structure with an opening on its side. The sunshade device is disposed inside the storage tube and can extend or retract through the opening. The drive disc of the double-disc damper is rotatably connected to the base, and the driven disc of the double-disc damper is connected to the bottom surface of the storage tube. When the drive disc of the double-disc damper rotates, the driven disc of the double-disc damper drives the storage tube to rotate, thereby changing the orientation of the opening. Therefore, when using this car sunshade structure, the user first installs the base on one side of the car window, and then manually rotates the drive disc of the double-disc damper. At this time, the drive disc transmits torque through the friction between itself and the driven disc, thereby driving the driven disc to rotate synchronously. The rotating driven disc can further drive the storage tube connected to it to rotate, and change the orientation of the opening on the side of the storage tube. By changing the orientation of the opening, users can manually and flexibly adjust the angle at which the sunshade extends from the retractable tube, allowing it to fit snugly against the curved surface of the car window and extend and retract freely along the window's curvature. This significantly improves the uniformity and overall performance of the sunshade effect. Furthermore, the dual-disc damper, which serves as the angle adjustment structure, provides damping between the driving and driven discs, ensuring smooth and controllable rotation of the retractable tube. This further enhances the accuracy and stability of the angle adjustment, significantly improving the user experience and safety during the adjustment process. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structure of the car sunshade provided in the embodiment of this utility model;

[0016] Figure 2 This is a first structural disassembly diagram of the car sunshade structure provided in an embodiment of the present utility model;

[0017] Figure 3 This is a second structural disassembly diagram of the car sunshade structure provided in an embodiment of the present utility model;

[0018] Figure 4 A structural cross-sectional view of the car sunshade structure provided in an embodiment of this utility model;

[0019] Figure 5 for Figure 4 A schematic diagram of the structure of part A in the middle;

[0020] Figure 6 A schematic diagram of the structure of the dual-disc damper provided in this embodiment of the utility model.

[0021] The annotations in the attached figures are explained as follows:

[0022] 10. Base; 20. Storage tube; 31. Rotating shaft; 32. Sunshade curtain; 33. First motor; 34. Second motor; 35. Guide rib; 40. Double disc damper; 41. Drive disc; 42. Driven disc; 51. First fixed end cover; 52. Second fixed end cover. Detailed Implementation

[0023] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0024] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and sliding situation between the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0025] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0026] Please refer to Figure 1-6 As shown, this utility model proposes a car sunshade structure, including a base 10, a storage tube 20, a sunshade device, and a double-disc damper 40. The storage tube 20 has a hollow structure and an opening on its side. The sunshade device is disposed inside the storage tube 20 and can extend or retract through the opening. The drive disc 41 of the double-disc damper 40 is rotatably connected to the base 10, and the driven disc 42 of the double-disc damper 40 is connected to the bottom surface of the storage tube 20. When the drive disc 41 of the double-disc damper 40 rotates, the driven disc 42 of the double-disc damper 40 drives the storage tube 20 to rotate, thereby changing the orientation of the opening.

[0027] For details, please refer to Figure 6As shown, the dual-disc damper 40 (also known as a 360-degree rotating damping shaft or an arbitrary-stop damping shaft) features flexible rotation and smooth opening, enabling it to stop and position at any angle. The dual-disc damper 40 consists of a drive disc 41 and a driven disc 42, which are coaxially mounted and can rotate 360 ​​degrees relative to each other. Power transmission is achieved through friction generated by close contact between the drive disc 41 and the driven disc 42. When the drive disc 41 rotates under external force, the friction drives the driven disc 42 to rotate synchronously, stopping at the adjusted angle. This ensures the dual-disc damper 40 can stably remain at any desired position, effectively preventing accidental slippage or rotation. Furthermore, the dual-disc damper 40 has a damping control function; by adjusting the friction between the drive disc 41 and the driven disc 42, the rotation speed can be limited and buffered, preventing excessively fast or sudden rotation. This ensures smooth and controllable adjustment of the opening's orientation, allowing the sunshade device extending from the opening to adjust the shading angle more flexibly, precisely, and safely.

[0028] Compared with existing technologies, when using the car sunshade structure proposed in this embodiment, the user first installs the base 10 on one side of the car window, and then manually rotates the drive disc 41 of the dual-disc damper 40. At this time, the drive disc 41 transmits torque through the friction between it and the driven disc 42, thereby driving the driven disc 42 to rotate synchronously. The rotating driven disc 42 can further drive the connected storage cylinder 20 to rotate, and change the orientation of the opening on the side of the storage cylinder 20. Through this change of opening orientation, the user can manually and flexibly adjust the shading angle of the sunshade device extending from the storage cylinder 20 through the opening, so that it can fit closely to the curved surface of the car window and can freely extend and retract along the curved surface of the window, thereby significantly improving the uniformity and overall performance of the sunshade effect. In addition, as a shading angle adjustment structure, the damping effect between the drive disc 41 and the driven disc 42 of the dual-disc damper 40 can make the rotation of the storage cylinder 20 smooth and controllable, further improving the accuracy and stability of the shading angle adjustment, thereby significantly improving the user experience and safety of the adjustment process.

[0029] In some embodiments of this application, the driving disk 41 and the driven disk 42 of the dual-disc damper 40 are both disc structures and are coaxially arranged.

[0030] Specifically, the dual-disc damper 40 with a disc structure design, also known as a disc damping shaft, has a mature manufacturing process, a simple structure, and excellent durability. It should be noted that the structure and working principle of the dual-disc damper 40 with a disc structure design are existing mature technologies, and will not be elaborated upon here.

[0031] In some embodiments of this application, the sunshade device includes a drive motor, a rotating shaft 31, and a sunshade curtain 32. The output shaft of the drive motor is connected to the rotating shaft 31. The rotating shaft 31 is located inside the storage cylinder 20 and is coaxially arranged with the storage cylinder 20. One end of the sunshade curtain 32 is fixedly connected to the rotating shaft 31, and the sunshade curtain 32 can be rolled up or unfolded around the rotating shaft 31. When the drive motor drives the rotating shaft 31 to rotate in the forward direction through the output shaft, the sunshade curtain 32 unfolds around the rotating shaft 31 and extends out of the storage cylinder 20 through the opening. When the drive motor drives the rotating shaft 31 to rotate in the reverse direction through the output shaft, the sunshade curtain 32 rolls up around the rotating shaft 31 and retracts into the storage cylinder 20 through the opening.

[0032] Specifically, the output shaft of the drive motor is directly connected to the rotating shaft 31, ensuring effective power transmission and providing the core driving force for the extension and retraction of the sunshade 32. The rotating shaft 31 is located inside the storage tube 20 and coaxially arranged with it, further ensuring the stable and smooth winding and unfolding of the sunshade 32. When the drive motor rotates in the reverse direction, the rotating shaft 31 drives the sunshade 32 to wind up, and the sunshade 32 retracts into the storage tube 20 through the opening; when the drive motor rotates in the forward direction, the rotating shaft 31 drives the sunshade 32 to unfold, and the sunshade 32 extends out of the storage tube 20 through the opening. This opening has been oriented by a dual-disc damper 40, allowing the extended sunshade 32 to better conform to the contours of the car window, improving shading performance and reducing light leakage. Therefore, by combining the forward and reverse rotation of the drive motor with the flexible adjustment of the opening orientation of the storage tube 20, the smooth extension and retraction and precise positioning of the sunshade 32 can be effectively ensured, thereby enhancing the overall shading effect.

[0033] In some embodiments of this application, the end of the rotating shaft 31 is recessed towards the center to form a mounting position for mounting the drive motor, the drive motor being disposed at the mounting position.

[0034] Specifically, by placing the drive motor within the mounting position formed by the recess from the end of the rotating shaft 31 towards the center, the overall structure of the sunshade device becomes more compact, eliminating the need for additional installation space for the drive motor and further enhancing the structural integration between the drive motor and the rotating shaft 31. Furthermore, this mounting method facilitates coaxial connection between the drive motor and the rotating shaft 31, significantly improving the efficiency and stability of power transmission.

[0035] In some embodiments of this application, the dual-disc damper 40 includes a first damper rotatably connected to the left end of the base 10 and a second damper rotatably connected to the right end of the base 10. The first damper and the second damper have the same structure. The left end of the storage tube 20 is connected to the first damper, and the right end of the storage tube 20 is connected to the second damper.

[0036] Specifically, a dual-disc damper 40 (i.e., a first damper or a second damper) is installed at each of the left and right ends of the base 10, which can support more precise damping force adjustment, improve the adjustment accuracy of the opening orientation, and further optimize the adjustment effect of the sunshade 32's blocking angle (i.e., the tilt angle along the opening). In addition, configuring two dual-disc dampers 40 can effectively improve the fault tolerance of the automotive sunshade structure. Even if the damping performance of one end of the dual disc changes slightly, the entire sunshade system can still maintain a stable adjustment state, thereby improving the reliability and durability of the automotive sunshade structure.

[0037] In some embodiments of this application, the drive motor includes a first motor 33 located at the left end of the rotating shaft 31 and a second motor 34 located at the right end of the rotating shaft 31.

[0038] Specifically, each end of the rotating shaft 31 is equipped with a drive motor (i.e., the first motor 33 or the second motor 34), enabling synchronous dual-end drive of the rotating shaft 31. This results in a more even power distribution and higher overall drive efficiency. Furthermore, the dual-drive motor design enhances the reliability of the entire shading system; even if one motor fails, the other can still maintain some functionality. The coordinated mechanism of the dual drive motors also allows for more precise control of the tension of the sunshade curtain 32, preventing it from becoming skewed or loose, and meeting the performance requirements of larger or more complex sunshade curtains 32.

[0039] In some embodiments of this application, the car sunshade structure further includes a first fixed end cap 51 located at the left end of the base 10 and a second fixed end cap 52 located at the right end of the base 10. The first fixed end cap 51 and the second fixed end cap 52 have the same structure and are respectively connected to the left and right ends of the storage tube 20. One side of the first fixed end cap 51 is connected to the driven plate 42 of the first damper, and the other side of the first fixed end cap 51 is connected to the first motor 33. One side of the second fixed end cap 52 is connected to the driven plate 42 of the second damper, and the other side of the second fixed end cap 52 is connected to the second motor 34.

[0040] Specifically, the first fixed end cap 51 and the second fixed end cap 52 have the same structure and are both disc-shaped, which effectively simplifies component design and manufacturing process, and facilitates later maintenance. The two fixed end caps are connected to the left and right ends of the storage cylinder 20 respectively (the first fixed end cap 51 is connected to the left end of the storage cylinder 20, and the second fixed end cap 52 is connected to the right end of the storage cylinder 20) and are coaxially arranged, which can firmly support the storage cylinder 20 and its internal components (including the rotating shaft 31, drive motor, and sunshade 32), ensuring that the storage cylinder 20 remains stable during operation and preventing shaking or displacement. One side of the fixed end cap is connected to the double-disc damper 40, and the other side is connected to the motor, forming a modular structure of the drive motor, fixed end cap, and double-disc damper 40. This modular structure is also connected to the storage cylinder 20, which facilitates direct power transmission and synchronous control, improves drive efficiency and opening orientation adjustment response speed, and facilitates assembly and disassembly, enhancing the maintainability and flexibility of the overall structure.

[0041] In some embodiments of this application, the sunshade device further includes a plurality of guide ribs 35, all of which are connected to the sunshade curtain 32 and arranged in a direction perpendicular to the axis of the rotating shaft 31.

[0042] Specifically, the guide ribs 35, acting as reinforcing components, effectively enhance the overall structural rigidity of the sunshade 32, preventing wrinkles, deformation, or loosening during unfolding and rolling, ensuring the sunshade 32 remains flat and tightly fitted to the car window. As guiding components, the guide ribs 35 also guide the sunshade 32 during unfolding and rolling, ensuring it moves along the correct path, avoiding skewing, twisting, or jamming, thus improving the operational reliability and service life of the sunshade device. The axis of the rotating shaft 31 is aligned with the rolling direction of the sunshade 32, and the guide ribs 35 are arranged perpendicular to the axis of the rotating shaft 31. This not only prevents the guide ribs 35 from interfering with or piling up, but also evenly distributes surface tension during the rolling of the sunshade 32, ensuring smooth unfolding and rolling.

[0043] In some embodiments of this application, the guide rib 35 includes four ribs with identical structures, two of which are located on the left and right sides of the sunshade curtain 32 respectively, and the other two ribs are separately disposed in the central area of ​​the sunshade curtain 32.

[0044] Specifically, the left and right side ribs provide sturdy support for the edges of the sunshade 32, effectively preventing edge deformation or curling; the two central ribs are distributed in the central area of ​​the sunshade 32, strengthening the central support and preventing sagging or loosening in the middle section, thus improving the overall flatness and structural stability of the sunshade 32. Through the rational layout of the left, right, and central ribs, the sunshade 32 remains flat and wrinkle-free when unfolded, resulting in a more aesthetically pleasing appearance and uniform shading effect. Of course, in practical applications, the number, position, and arrangement of the guide ribs 35 can be flexibly selected based on factors such as the car model, the size of the sunshade 32, and the usage environment to meet diverse sunshade needs and achieve optimal performance.

[0045] In some embodiments of this application, the base 10 is connected to the bottom of the car window, and the guide rib 35 is an elastic steel strip; when the sunshade 32 extends upward through the opening into the storage tube 20, the elastic steel strip is in a flat state; when the sunshade 32 retracts downward through the opening into the storage tube 20, the elastic steel strip is in a spiral wound state.

[0046] Specifically, the elastic steel strip possesses excellent elasticity and resilience, maintaining straightness and rigidity when the sunshade 32 is unfolded, ensuring a smooth, wrinkle-free surface. During winding, it maintains a spiral shape, facilitating smooth retraction into the storage tube 20 while saving space and ensuring a compact and aesthetically pleasing overall structure. The base 10 can be installed on the inner or outer side of the bottom of the window frame (such as the windshield and rear window) using screws, clips, or adhesive, fully utilizing the existing structure for a stable installation. As an innovative and advanced design, the sunshade 32 extends upwards, and with the support of the elastic steel strip, it ensures good flatness and sufficient rigidity when unfolded, effectively preventing sagging and deformation caused by gravity or wind. It also flexibly adapts to various installation environments and usage requirements, significantly improving overall performance and user experience.

[0047] The car sunshade structure provided by this utility model allows for flexible adjustment of the sunshade curtain 32's blocking angle to meet different light and viewing needs, achieving a personalized sunshade effect. Furthermore, the sunshade curtain 32 extends from bottom to top, enhancing its tension and stability, effectively preventing natural sagging and facilitating user operation. In addition, the car sunshade curtain structure employs a balanced left-right adjustment design, ensuring the sunshade curtain 32's flatness and stability in the lateral direction, avoiding wrinkles and deformation, and improving overall aesthetics and user comfort. In conclusion, this car sunshade curtain structure not only enhances the sunshade effect and user experience but also improves the product's durability and applicability, meeting diverse car sunshade needs.

[0048] It should be noted that the technical solutions of the various embodiments of this utility model can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0049] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. An automotive sunshade structure, characterized by, The device includes a base, a storage tube, a sunshade device, and a dual-disc damper. The storage tube is hollow with an opening on its side. The sunshade device is located inside the storage tube and can extend or retract through the opening. The drive disc of the dual-disc damper is rotatably connected to the base, and the driven disc of the dual-disc damper is connected to the bottom surface of the storage tube. When the drive disc of the dual-disc damper rotates, the driven disc of the dual-disc damper drives the storage tube to rotate, thereby changing the orientation of the opening.

2. The sunshade structure according to claim 1, wherein, The driving disk and driven disk of the dual-disc damper are both circular disks and are coaxially arranged.

3. The sunshade structure according to claim 1, wherein, The sunshade device includes a drive motor, a rotating shaft, and a sunshade curtain. The output shaft of the drive motor is connected to the rotating shaft. The rotating shaft is located inside the storage tube and is coaxially arranged with the storage tube. One end of the sunshade curtain is fixedly connected to the rotating shaft, and the sunshade curtain can be rolled up or unfolded around the rotating shaft. When the drive motor drives the rotating shaft to rotate in the forward direction through the output shaft, the sunshade curtain unfolds around the rotating shaft and extends out of the storage tube through the opening. When the drive motor drives the rotating shaft to rotate in the reverse direction through the output shaft, the sunshade curtain rolls up around the rotating shaft and retracts into the storage tube through the opening.

4. The sunshade structure according to claim 3, wherein, The end of the rotating shaft is recessed towards the center to form a mounting position for mounting the drive motor, and the drive motor is disposed in the mounting position.

5. The automotive sunshade structure according to claim 4, wherein The dual-disc damper includes a first damper rotatably connected to the left end of the base and a second damper rotatably connected to the right end of the base. The first damper and the second damper have the same structure. The left end of the storage tube is connected to the first damper, and the right end of the storage tube is connected to the second damper.

6. The automotive sunshade structure according to claim 5, wherein The drive motor includes a first motor located at the left end of the shaft and a second motor located at the right end of the shaft.

7. The automotive sunshade structure according to claim 6, characterized in that, The car sunshade structure also includes a first fixed end cap located at the left end of the base and a second fixed end cap located at the right end of the base. The first fixed end cap and the second fixed end cap have the same structure and are respectively connected to the left end and the right end of the storage tube. One side of the first fixed end cap is connected to the driven plate of the first damper, and the other side of the first fixed end cap is connected to the first motor. One side of the second fixed end cap is connected to the driven plate of the second damper, and the other side of the second fixed end cap is connected to the second motor.

8. The automotive sunshade structure according to claim 3, wherein The sunshade device also includes several guide ribs, all of which are connected to the sunshade curtain and arranged in a direction perpendicular to the axis of rotation.

9. The automotive sunshade structure according to claim 8, wherein, The guide ribs include four ribs with identical structures, two of which are located on the left and right sides of the sunshade curtain respectively, and the other two ribs are separately arranged in the central area of ​​the sunshade curtain.

10. The automotive sunshade structure according to claim 8, wherein, The base is connected to the bottom of the car window, and the guide rib is an elastic steel strip. When the sunshade extends upward through the opening into the storage tube, the elastic steel strip is in a flat state. When the sunshade retracts downward through the opening into the storage tube, the elastic steel strip is in a spiral wound state.

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