A thickness detection equipment for cloth sand production
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANTONG HANSI FURNITURE CO LTD
- Filing Date
- 2026-04-03
- Publication Date
- 2026-06-09
Smart Images

Figure CN122170781A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of sofa fabric production technology, specifically to a thickness detection device for fabric sofa fabric production. Background Technology
[0002] When producing upholstered sofa fabrics, thickness testing is a crucial part of the quality inspection process to ensure that the fabric thickness meets design standards and usage requirements. Currently, in the production of upholstered sofa fabrics, traditional thickness testing methods mostly rely on manual measurement using calipers or thickness gauges. This method is not only inefficient and difficult to meet the testing needs of large-scale, continuous production, but also has a large degree of subjectivity and error in manual operation, which can easily lead to inaccurate test results.
[0003] To address the aforementioned issues, existing technology (Chinese Patent No. CN216283282U, published on April 12, 2022) discloses a fabric thickness detection device, comprising a housing with fabric inlets on both the left and right side walls. A detection base plate is welded to the bottom inner side of the housing, and a fixing sleeve is welded to the top inner side of the housing. A spring is installed on the top inner side of the fixing sleeve. A control device is configured to set the laser rangefinder and the light-collecting plate to detect zero data when the detection roller contacts the top of the detection base plate. When the detection roller contacts the top surface of the fabric, the fabric pushes the detection roller, movable rod, and movable plate upwards, causing the movable plate to compress the spring. This causes the movable rod to retract into the fixing sleeve, and the upward movement of the movable rod drives the laser rangefinder upwards, changing the distance between the laser rangefinder and the light-collecting plate. This change represents the fabric thickness. A motor drives a winding roller to rotate, ensuring that all fabric is detected by the detection roller, thus achieving rapid and complete fabric detection.
[0004] There is also prior art 2 (Chinese patent with announcement number CN215114417U, announcement date 2021-12-10) a spunlace nonwoven fabric thickness monitoring device, which relates to the field of fabric production equipment technology, including a fabric to be tested and a base plate. Support legs are fixedly connected to both sides of the bottom of the base plate, and support plates are fixedly connected to both ends of the bottom of the base plate. The top of the two support plates is fixedly connected to the same mounting housing. A laser rangefinder is fixedly installed on the bottom outer wall of the mounting housing. A PLC is fixedly installed in the inner cavity of the mounting housing. A controller is fixedly connected to the top outer wall of the mounting housing, and a display screen is fixedly installed on the top of the controller. It has the effect of more conveniently detecting the thickness of spunlace nonwoven fabric.
[0005] While existing technologies can detect the thickness of fabrics, in actual testing, dust, lint, and other impurities easily adhere to the fabric surface. If these are not cleaned in time, they can cause deviations in the laser detection results, affecting the accuracy of the thickness data. At the same time, the fabric of upholstered sofas is soft and is prone to wrinkles due to uneven tension or external forces during transport and testing. The thickness measurement value of the wrinkled areas will be much greater than the actual thickness, resulting in false detections.
[0006] Therefore, we propose a thickness detection device for fabric sofa production to solve the problems mentioned above. Summary of the Invention
[0007] The purpose of this invention is to provide a thickness detection device for fabric sofa production, in order to solve the problems mentioned in the background art. In the actual testing process, the fabric surface is prone to dust, lint and other impurities. If they are not cleaned in time, they will cause deviations in the laser detection results and affect the accuracy of the thickness data. At the same time, fabric sofas are soft and are prone to wrinkles due to uneven tension or external force during transportation and testing. The thickness measurement value of the wrinkled parts will be much larger than the actual thickness, causing false detection.
[0008] To achieve the above objectives, the present invention provides the following technical solution: a thickness detection device for fabric sofa production, comprising a detection table, a movable frame disposed above the detection table, and laser detectors fixedly connected to the upper and lower sides of the movable frame, each with a corresponding position; detection table surfaces for fixing the fabric are fixedly connected to both sides of the upper surface of the detection table, and the fabric passes through the center of the movable frame and its thickness is detected by the laser detectors; a vertical sliding box is slidably disposed on the movable frame, and a smoothing mechanism is disposed between the interior of the vertical sliding box and the upper surface of the detection table; the smoothing mechanism achieves smoothing treatment of the fabric to be tested through the contact action between its included abutment plate and the horizontal sliding box; a cleaning mechanism is disposed on the movable frame, and the cleaning mechanism drives the included squeezing plate to rotate through the movement of the movable frame, thereby achieving cleaning of the fabric surface.
[0009] Preferably, a motor is fixedly connected to the side of the testing platform, and a threaded rod is fixedly connected to the output end of the motor. A limiting groove is fixedly connected to the side of the upper surface of the testing platform, and the movable frame is slidably connected inside the limiting groove.
[0010] Preferably, a connecting frame is fixedly connected to the side of the movable frame, and a threaded block is fixedly connected to the connecting frame. The threaded block and the threaded rod are threadedly connected. A support strip is fixedly connected to the movable frame to provide auxiliary support for the fabric through which it passes.
[0011] Preferably, the cleaning mechanism includes a limiting rod, which is slidably connected above the movable frame. The lower end of the limiting rod is fixedly connected to an auxiliary pressure plate with a hollow structure, and the upper end of the limiting rod is fixedly connected to the upper surface of the movable frame with a second spring. The auxiliary pressure plate is in contact with the upper surface of the fabric under the elastic drive of the second spring.
[0012] Preferably, the lower surface of the auxiliary pressure plate is provided with an exhaust hole, and a connecting hose is provided through the side of the auxiliary pressure plate. A soft cavity is fixedly connected to the lower surface of the connecting frame, and a rotating shaft is rotatably connected to the connecting frame. A gear is fixedly connected to the upper end of the rotating shaft, and a pressing plate is fixedly connected to the lower end of the rotating shaft. A rack is fixedly connected to the lower surface of the detection table, and the rack and the gear mesh with each other.
[0013] Preferably, the smoothing mechanism includes a first protrusion, which is fixedly connected to the upper surface side of the testing table, and a second protrusion is also fixedly connected to the upper surface of the testing table. The front and rear sides of the first protrusion are arranged in an inclined structure, and the left and right sides of the second protrusion are arranged in an inclined structure.
[0014] Preferably, the vertical sliding box is slidably connected to the movable frame, and a sliding plate for limiting its position is fixedly connected to the side of the vertical sliding box. A horizontal sliding box is slidably connected inside the vertical sliding box. A second spring is fixedly connected between the side of the horizontal sliding box and the inner wall of the vertical sliding box. An abutment plate is fixedly connected to the other side of the horizontal sliding box.
[0015] Preferably, the vertical sliding box slides vertically along the movable frame by abutting against the first protrusion. After the vertical sliding box moves upward, the abutting plate abuts against the second protrusion. The horizontal sliding box slides horizontally along the vertical sliding box by abutting against the second protrusion.
[0016] Preferably, an auxiliary roller is rotatably connected inside the transverse sliding box, and a positioning soft strip is fixedly connected inside the transverse sliding box. The positioning soft strip corresponds one-to-one with the position of the auxiliary roller, and the auxiliary roller rotates by friction with the fabric.
[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) A movable frame is provided. When inspecting the fabric, clamp both ends of the fabric onto the clamping frame and pass it through the movable frame. Start the motor. The movable frame moves smoothly along the limit slide under the threaded drive. The laser detector on it can continuously scan the thickness of the fabric. At the same time, the support strip lifts the fabric to make it flat, avoids sagging, and ensures the accuracy of the inspection.
[0018] (2) The auxiliary pressure plate is pressed against the upper surface of the fabric under the action of the second spring, and the fabric is initially smoothed. When the moving frame moves, the gear and rack on the connecting frame mesh and rotate, and drive the extrusion plate to rotate through the rotating shaft, intermittently extruding the soft cavity, so that air enters the auxiliary pressure plate through the connecting hose and is sprayed out from the exhaust hole, effectively blowing away the dust, lint and other small debris attached to the fabric surface, ensuring that the fabric surface is clean before the thickness detection, and avoiding impurities from interfering with the laser detection results.
[0019] (3) The moving frame drives the vertical sliding box to move to the first protrusion. The vertical sliding box is lifted up along its inclined surface. Then the contact plate of the inner horizontal sliding box contacts the second protrusion and is pushed to slide horizontally by the horizontal component force. The auxiliary roller at the bottom rolls to smooth the fabric. The moving frame automatically smooths the fabric during the movement. No additional manual operation is required, saving labor costs. It effectively avoids fabric stacking and ensures the flatness of the fabric, thereby greatly improving the accuracy of fabric thickness detection and ensuring reliable detection results.
[0020] (4) The positioning soft strips fixed inside the transverse sliding box correspond one-to-one with the positions of the auxiliary rollers. The positioning soft strips have a certain elasticity and friction, which can scrape off the dust and lint attached to the surface of the fabric when the auxiliary rollers roll and smooth it, thereby achieving the dust removal treatment of the lower surface of the fabric and reducing the influence of dust on the subsequent laser thickness measurement.
[0021] (5) After the vertical sliding box completely passes the first protrusion, it slides down the moving frame and resets by its own weight, so that the auxiliary roller no longer contacts the lower surface of the fabric. This prevents the horizontal sliding box from sliding down and resetting under the first spring's reset force when the subsequent contact plate separates from the second protrusion, which would cause the auxiliary roller to cause wrinkles in the fabric. As the moving frame continues to move, the vertical sliding box continuously contacts, slides, and resets with the subsequent first and second protrusions, driving the auxiliary roller to repeatedly smooth the fabric horizontally, ensuring that the fabric height in the detection area is flat, providing a precise and reliable detection surface for the laser detector, and ensuring that the thickness detection data is true and accurate. Attached Figure Description
[0022] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the three-dimensional bottom view structure of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the mobile frame of the present invention; Figure 4 For the present invention Figure 3 Enlarged structural diagram at point A in the middle; Figure 5 This is a schematic diagram of the three-dimensional structure of the vertical sliding box of the present invention; Figure 6 This is a schematic diagram of the three-dimensional structure of the horizontal sliding box of the present invention; Figure 7 This is a schematic diagram of the three-dimensional structure of the positioning soft strip of the present invention; Figure 8 This is a schematic diagram of the three-dimensional structure of the second protrusion of the present invention; Figure 9 This is a schematic diagram of the three-dimensional structure of the extrusion plate of the present invention.
[0023] In the diagram: 1. Testing platform; 2. Limiting slide groove; 3. Moving frame; 4. Motor; 5. Threaded rod; 6. Threaded block; 7. Connecting frame; 8. Rack; 9. Gear; 10. Horizontal sliding box; 11. Sliding plate; 12. Vertical sliding box; 13. Auxiliary roller; 14. First spring; 15. Laser detector; 16. First protrusion; 17. Second protrusion; 18. Clamping frame; 19. Soft cavity; 20. Connecting hose; 21. Contact plate; 22. Limiting rod; 23. Second spring; 24. Auxiliary pressure plate; 25. Exhaust hole; 26. Rotating shaft; 27. Extrusion plate; 28. Positioning soft strip; 29. Support strip. Detailed Implementation
[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0025] Example 1: As Figure 1 , Figure 2 and Figure 3 The present invention provides the following technical solution: a thickness detection device for fabric sofa production, wherein a movable frame 3 is provided above the detection table 1, and laser detectors 15 with corresponding positions are fixedly connected to the upper and lower sides of the movable frame 3; detection table 1 for fixing the fabric is fixedly connected to both sides of the upper surface of the detection table 1, and the fabric passes through the center of the movable frame 3 and the thickness is detected by the laser detector 15; a motor 4 is fixedly connected to the side of the detection table 1, and a threaded rod 5 is fixedly connected to the output end of the motor 4; a limiting groove 2 is fixedly connected to the side of the upper surface of the detection table 1; the movable frame 3 is slidably connected inside the limiting groove 2; a connecting frame 7 is fixedly connected to the side of the movable frame 3, and a threaded block 6 is fixedly connected to the connecting frame 7, and the threaded block 6 is threadedly connected to the threaded rod 5; and a support strip 29 corresponding to the fabric passing through it is fixedly connected to the movable frame 3 for auxiliary support.
[0026] When the fabric needs to be inspected, the fabric is passed through the moving frame 3 and clamped at both ends on the clamping frame 18. The motor 4 is started, and the motor 4 drives the threaded rod 5 to rotate. The threaded rod 5 is connected to the threaded block 6 through a thread, which drives the connecting frame 7 and the moving frame 3 to move smoothly along the length direction of the limiting slide groove 2. During this process, the laser detector 15 on the moving frame 3 will continuously scan the thickness of the fabric passing below. At the same time, the support bar 29 fixed on the moving frame 3 supports the fabric from below, ensuring that the fabric remains flat during the inspection process and avoiding the impact of the inspection accuracy due to the fabric's own weight sagging.
[0027] Example 2: To further improve the surface cleanliness of the fabric during inspection and prevent dust, lint, and other impurities from adhering to the fabric surface and affecting the accuracy of laser inspection, this equipment is also equipped with a cleaning mechanism, such as... Figure 2 , Figure 3 and Figure 8 The present invention provides the following technical solution: a thickness detection device for fabric sofa production, wherein a cleaning mechanism is provided on a movable frame 3, and the cleaning mechanism drives the squeezing plate 27 contained therein to rotate by the movement of the movable frame 3, thereby cleaning the surface of the fabric. The cleaning mechanism includes a limiting rod 22, which is slidably connected to the upper part of the movable frame 3, and the lower end of the limiting rod 22 is fixedly connected to an auxiliary pressure plate 24 with a hollow structure, and the upper end of the limiting rod 22 is fixedly connected to the upper surface of the movable frame 3. There is a second spring 23. The auxiliary pressure plate 24 is in contact with the upper surface of the fabric under the elastic drive of the second spring 23. The lower surface of the auxiliary pressure plate 24 is provided with an exhaust hole 25, and a connecting hose 20 is provided through the side of the auxiliary pressure plate 24. The lower surface of the connecting frame 7 is fixedly connected to a soft cavity 19, and a rotating shaft 26 is rotatably connected to the connecting frame 7. The upper end of the rotating shaft 26 is fixedly connected to a gear 9, and the lower end of the rotating shaft 26 is fixedly connected to a pressing plate 27. The lower surface of the detection table 1 is fixedly connected to a rack 8, and the rack 8 and the gear 9 mesh with each other.
[0028] Under the continuous elastic force of the second spring 23, the auxiliary pressure plate 24 is always tightly pressed against the upper surface of the fabric, forming a stable downward pressure on the fabric and performing preliminary smoothing treatment. At the same time, as the moving frame 3 moves, the connecting frame 7 moves synchronously. The gear 9 on the connecting frame 7 meshes with the rack 8 fixed on the lower surface of the detection table 1, thereby driving the gear 9 to rotate. The rotation of the gear 9 is transmitted to the lower end of the extrusion plate 27 through the rotating shaft 26, causing the extrusion plate 27 to rotate above and to the side of the fabric. During the rotation, the extrusion plate 27 intermittently extrudes the soft cavity 19 on the lower surface of the connecting frame 7. After the air inside the soft cavity 19 is compressed, it is forced into the hollow interior of the auxiliary pressure plate 24 through the connecting hose 20, and finally sprayed out from the exhaust hole 25 opened on the lower surface of the auxiliary pressure plate 24, blowing away the debris on the fabric surface, ensuring that the fabric is clean before thickness detection and avoiding interference with laser detection.
[0029] Example 3: To further ensure the flatness of the fabric during the testing process and prevent deviations in test data due to fabric stacking or wrinkles, this equipment is also equipped with a smoothing mechanism, such as... Figures 3-8 The present invention provides the following technical solution: a thickness detection device for fabric sofa production, wherein a vertical sliding box 12 is slidably arranged on a movable frame 3, and a smoothing mechanism is provided between the interior of the vertical sliding box 12 and the upper surface of the detection table 1. The smoothing mechanism achieves smoothing treatment of the fabric to be detected through the contact action between its included abutment plate 21 and the horizontal sliding box 10. The smoothing mechanism includes a first protrusion 16, which is fixedly connected to the side of the upper surface of the detection table 1, and a second protrusion 17 is also fixedly connected to the upper surface of the detection table 1. The front and rear sides of the first protrusion 16 are arranged in an inclined structure, and the left and right sides of the second protrusion 17 are arranged in an inclined structure. The vertical sliding box 12 is slidably connected to the movable frame 3, and a device for adjusting the thickness of the fabric is fixedly connected to the side of the vertical sliding box 12. The sliding plate 11 is limited, and the horizontal sliding box 10 is slidably connected inside the vertical sliding box 12. A second spring 23 is fixedly connected between the side of the horizontal sliding box 10 and the inner wall of the vertical sliding box 12. An abutment plate 21 is fixedly connected to the other side of the horizontal sliding box 10. The vertical sliding box 12 slides vertically along the moving frame 3 by abutting against the first protrusion 16. After the vertical sliding box 12 moves upward, the abutment plate 21 abuts against the second protrusion 17. The horizontal sliding box 10 slides horizontally along the vertical sliding box 12 by abutting against the second protrusion 17. An auxiliary roller 13 is rotatably connected inside the horizontal sliding box 10. A positioning soft strip 28 is fixedly connected inside the horizontal sliding box 10, and the positioning soft strip 28 corresponds one-to-one with the position of the auxiliary roller 13. The auxiliary roller 13 rotates by friction with the fabric.
[0030] The vertical sliding box 12, which is slidably mounted on the moving frame 3, moves with the moving frame 3. When the vertical sliding box 12 moves to the position of the first protrusion 16 on the upper surface of the detection table 1, the bottom of the vertical sliding box 12 contacts the inclined side of the first protrusion 16 and generates a resisting action. Since the front and rear sides of the first protrusion 16 are inclined, the vertical sliding box 12 will slide upward along the inclined surface of the first protrusion 16 under the pushing force of movement, so that the entire vertical sliding box 12 is lifted upward along the moving frame 3. After the vertical sliding box 12 moves upward, its interior... The contact plate 21 on the side of the horizontal sliding box 10 will abut against the second protrusion 17 on the upper surface of the detection table 1. The left and right sides of the second protrusion 17 are inclined. After the contact plate 21 contacts the inclined side of the second protrusion 17, it will be subjected to a horizontal component force. This component force pushes the horizontal sliding box 10 to overcome the elastic force of the first spring 14 and slide horizontally away from the second protrusion 17 along the interior of the vertical sliding box 12. During the horizontal sliding process, the auxiliary roller 13 rotatably connected to the bottom of the horizontal sliding box 10 will contact the fabric surface. The auxiliary roller 13 rolls and applies a lateral smoothing force to the fabric, stretching and smoothing it to both sides, improving the accuracy of fabric thickness detection and preventing inaccurate detection results due to fabric stacking. When the vertical sliding box 12 completely passes the first protrusion 16, it slides down and resets along the moving frame 3 under its own weight, preventing the auxiliary roller 13 from contacting the lower surface of the fabric and avoiding subsequent disengagement of the contact plate 21 from the second protrusion 17. The lateral sliding box 10 is then moved by the first spring 14. When the auxiliary roller 13 slides horizontally to reset under the action of the reset elastic force, it contacts the fabric and causes wrinkles. As the moving frame 3 continues to move, the vertical sliding box 12 will continuously engage in a cycle of contact, sliding, and reset with the subsequent first protrusion 16 and second protrusion 17, thereby driving the auxiliary roller 13 to repeatedly smooth the fabric horizontally, ensuring that the fabric is in a highly flat state throughout the entire detection area, providing an accurate and reliable detection surface for the laser detector 15, and ensuring the authenticity and accuracy of the thickness detection data.
[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A thickness detection device for fabric sofa production, comprising a detection table (1), a movable frame (3) above the detection table (1), and laser detectors (15) with corresponding positions fixedly connected to the upper and lower sides of the movable frame (3), and detection tables (1) for fixing the fabric fixedly connected to both sides of the upper surface of the detection table (1), and the thickness of the fabric is detected by the laser detectors (15) at the center of the movable frame (3), characterized in that, A vertical sliding box (12) is slidably arranged on the movable frame (3), and a smoothing mechanism is provided between the interior of the vertical sliding box (12) and the upper surface of the detection table (1). The smoothing mechanism achieves the smoothing treatment of the fabric to be tested by the contact plate (21) contained therein and the contact action of the horizontal sliding box (10). A cleaning mechanism is provided on the movable frame (3). The cleaning mechanism drives the squeezing plate (27) contained therein to rotate by the movement of the movable frame (3) to achieve the cleaning of the fabric surface.
2. The thickness detection equipment for fabric sofa production according to claim 1, characterized in that: A motor (4) is fixedly connected to the side of the testing platform (1), and a threaded rod (5) is fixedly connected to the output end of the motor (4). A limiting groove (2) is fixedly connected to the side of the upper surface of the testing platform (1), and the moving frame (3) is slidably connected inside the limiting groove (2).
3. The thickness detection equipment for fabric sofa production according to claim 2, characterized in that: The side of the movable frame (3) is fixedly connected to a connecting frame (7), and a threaded block (6) is fixedly connected to the connecting frame (7). The threaded block (6) is threadedly connected to the threaded rod (5). The movable frame (3) is fixedly connected to a support strip (29) that provides auxiliary support for the fabric it passes through.
4. The thickness detection equipment for fabric sofa production according to claim 3, characterized in that: The cleaning mechanism includes a limiting rod (22), which is slidably connected above the moving frame (3). The lower end of the limiting rod (22) is fixedly connected to an auxiliary pressure plate (24) with a hollow structure. The upper end of the limiting rod (22) is fixedly connected to the upper surface of the moving frame (3) with a second spring (23). The auxiliary pressure plate (24) is in contact with the upper surface of the fabric under the elastic drive of the second spring (23).
5. The thickness detection equipment for fabric sofa production according to claim 4, characterized in that: The lower surface of the auxiliary pressure plate (24) is provided with an exhaust hole (25), and a connecting hose (20) is provided through the side of the auxiliary pressure plate (24). A soft cavity (19) is fixedly connected to the lower surface of the connecting frame (7), and a rotating shaft (26) is rotatably connected to the connecting frame (7). A gear (9) is fixedly connected to the upper end of the rotating shaft (26), and a pressing plate (27) is fixedly connected to the lower end of the rotating shaft (26). A rack (8) is fixedly connected to the lower surface of the detection table (1), and the rack (8) and the gear (9) mesh with each other.
6. The thickness detection equipment for fabric sofa production according to claim 5, characterized in that: The smoothing mechanism includes a first protrusion (16), which is fixedly connected to the upper surface side of the testing table (1), and a second protrusion (17) is also fixedly connected to the upper surface of the testing table (1). The front and rear sides of the first protrusion (16) are arranged in an inclined structure, and the left and right sides of the second protrusion (17) are arranged in an inclined structure.
7. The thickness detection equipment for fabric sofa production according to claim 6, characterized in that: The vertical sliding box (12) is slidably connected to the movable frame (3), and a sliding plate (11) for limiting its position is fixedly connected to the side of the vertical sliding box (12). A horizontal sliding box (10) is slidably connected inside the vertical sliding box (12). A second spring (23) is fixedly connected between the side of the horizontal sliding box (10) and the inner wall of the vertical sliding box (12). An abutment plate (21) is fixedly connected to the other side of the horizontal sliding box (10).
8. The thickness detection equipment for fabric sofa production according to claim 7, characterized in that: The vertical sliding box (12) slides vertically along the moving frame (3) by abutting against the first protrusion (16). After the vertical sliding box (12) moves up, the abutting plate (21) abuts against the second protrusion (17). The horizontal sliding box (10) slides horizontally along the vertical sliding box (12) by abutting against the second protrusion (17) by the abutting plate (21).
9. The thickness detection equipment for fabric sofa production according to claim 8, characterized in that: The transverse sliding box (10) is rotatably connected to an auxiliary roller (13), and a positioning soft strip (28) is fixedly connected inside the transverse sliding box (10). The positioning soft strip (28) and the auxiliary roller (13) are in a one-to-one correspondence. The auxiliary roller (13) rotates by friction with the fabric.