Universal auxiliary feeding device for thin and thick materials and sewing machine

Abstract

The utility model discloses a universal auxiliary feeding device for thin and thick materials and a sewing machine, relates to the technical field of sewing machines, and aims to solve the problem that an existing auxiliary feeding device is not high in applicability. The one-way clutch driving assembly comprises a one-way clutch driving star wheel shaft and a driven shaft, one end of the one-way clutch driving star wheel shaft is connected with a driving gear through a bearing and a bearing cover, a driven gear in meshing transmission with the driving gear is arranged on the driven shaft, and the tooth number of the driving gear is smaller than that of the driven gear. The two ends of the one-way clutch driving star wheel shaft and the two ends of the driven shaft are installed on the bearing installation bases, the bearing installation bases are fixed to the installation support, and the belt dragging wheel assembly is connected with the driven shaft, so that large cloth feeding force can be achieved for sewing of thin materials and thick materials, and the purpose that the thin materials and the thick materials are universal is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewing machine technical field more specifically, relate to a kind of thin thick material general auxiliary feeding device and sewing machine. BACKGROUND

[0002] When the sewing machine is sewn, some thick cloth, only rely on feed dog often cannot feed cloth or cloth cannot pass presser foot, at this time, manual dragging is needed, but manual dragging usually causes broken needle, uneven stitch problem. The introduction of the rear drag wheel can effectively solve this phenomenon, and the rear drag wheel of the sewing machine mainly plays the role of auxiliary feeding during sewing.

[0003] At present, most of the sewing machines use wheel type rear drag wheel. This wheel type drag wheel has line contact with the sewing fabric, and the cloth feeding force is weak, so it can only be used for sewing thin materials. However, when sewing thick materials with this drag wheel, the fabric often jams or even blocks when passing through the presser foot, resulting in smooth sewing or causing problems such as small stitch, uneven stitch, etc. Moreover, this wheel type drag wheel cannot be lubricated, and the drag wheel wears out quickly, with poor durability.

[0004] Therefore, how to solve the problem of low applicability of the existing auxiliary feeding device is a problem that needs to be solved by the technical personnel in the field at present. UTILITY MODEL CONTENTS

[0005] Therefore, the purpose of the utility model is to provide an auxiliary feeding device for thin and thick materials, which can provide a large cloth feeding force for sewing thin and thick materials, achieving the purpose of being suitable for thin and thick materials.

[0006] Another purpose of the utility model is to provide a sewing machine comprising the auxiliary feeding device for thin and thick materials, which can improve the sewing performance of the sewing machine and improve the versatility of the sewing machine.

[0007] In order to achieve the above purpose, the utility model provides the following technical scheme:

[0008] An auxiliary feeding device for thin and thick materials, comprising:

[0009] a mounting bracket;

[0010] a one-way clutch driving assembly, the one-way clutch driving assembly comprising a one-way clutch driving star wheel shaft and a driven shaft, one end of the one-way clutch driving star wheel shaft being connected to a driving gear through a bearing and a bearing cover, the driven shaft being provided with a driven gear engaged with the driving gear for transmission, and the number of teeth of the driving gear being less than the number of teeth of the driven gear, both ends of the one-way clutch driving star wheel shaft and the driven shaft being mounted to a bearing mounting seat, and the bearing mounting seat being fixed to the mounting bracket;

[0011] The belt tow wheel assembly is connected with the driven shaft.

[0012] Preferably, one end of the one-way clutch driving star wheel shaft is connected with one end of the driving swing rod, the other end of the driving swing rod is connected with one end of the connecting rod through a shaft pin, and the other end of the connecting rod is connected with the adjusting swing rod connected with the main shaft.

[0013] Preferably, the driving gear is provided with a shell, a cavity formed between the shell and the bearing cover is provided with a roller compression spring and a one-way stop roller, the roller compression spring is arranged on the star wheel of the one-way clutch driving star wheel shaft, and the one-way stop roller is connected with the roller compression spring.

[0014] Preferably, the two ends of the one-way clutch driving star wheel shaft are both provided with oil seals and spacing washers.

[0015] Preferably, the belt tow wheel assembly comprises:

[0016] The tow wheel mounting plate is fixed to the mounting bracket;

[0017] The driving wheel is connected with the driven shaft;

[0018] The first synchronous pulley is movably mounted on the tow wheel mounting plate through the first synchronous wheel shaft;

[0019] The second synchronous pulley is movably connected with the tow wheel lifting and pressing connecting rod through the second synchronous wheel shaft;

[0020] The synchronous belt is arranged around the outer periphery of the driving wheel, the first synchronous pulley and the second synchronous pulley.

[0021] Preferably, the outer side of the synchronous belt is provided with a tensioning assembly for tensioning the synchronous belt.

[0022] Preferably, the tensioning assembly comprises:

[0023] The tensioning wheel is arranged on the outer side of the synchronous belt;

[0024] The tensioning connecting rod is movably connected with the tow wheel mounting plate at the first end, and movably connected with the intermediate shaft of the tensioning wheel at the second end;

[0025] The tensioning spring is connected with the second end of the tensioning connecting rod at the first end through a tensioning spring pin, and connected with the first end of the tow wheel lifting and pressing connecting rod at the second end through the tensioning spring pin.

[0026] Preferably, the belt tow wheel assembly further comprises a driving source, the driving source is arranged on the tow wheel mounting plate, the output end of the driving source is movably connected with the first end of the tow wheel lifting and pressing connecting rod, the second end of the tow wheel lifting and pressing connecting rod is movably connected with the second synchronous wheel shaft, and the middle part of the tow wheel lifting and pressing connecting rod is movably connected with the tow wheel mounting plate through a supporting pin shaft, so that the driving source drives the deflection movement of the tow wheel lifting and pressing connecting rod in the extension and retraction movement.

[0027] Preferably, the driving source is provided with a connecting seat fixed to the towing wheel mounting plate by a limiting pin.

[0028] Preferably, the movable rod of the driving source is provided with a connecting piece and an adjusting nut for limiting the position of the connecting piece, and the connecting piece is movably connected with the first end of the towing wheel lifting and pressing connecting rod.

[0029] A sewing machine, characterized by comprising the auxiliary feeding device for thin and thick materials as claimed in any one of the preceding claims.

[0030] The auxiliary feeding device for thin and thick materials comprises a mounting bracket, a one-way clutch driving assembly and a belt towing wheel assembly. The one-way clutch driving assembly comprises a one-way clutch driving star wheel shaft and a driven shaft. One end of the one-way clutch driving star wheel shaft is connected with a driving gear through a bearing and a bearing cover. The driving gear is synchronously rotated by the rotation of the one-way clutch driving star wheel shaft. The driven shaft is provided with a driven gear in meshing transmission with the driving gear. The driven shaft is rotated by the meshing transmission of the driving gear and the driven gear. The two ends of the one-way clutch driving star wheel shaft and the driven shaft are mounted on the bearing mounting seat on the mounting bracket to realize the positioning of the one-way clutch driving assembly. The belt towing wheel assembly is connected with the driven shaft and is rotated by the driven shaft to provide towing force for sewing thin and thick materials. The contact area between the sewing material and the towing wheel can be increased to ensure the smoothness of the whole sewing process, the flatness of the material and the uniformity and beauty of the sewing line. The number of teeth of the driving gear is less than that of the driven gear, so that greater torque can be obtained by speed reduction transmission to increase the towing force and realize the universality of thin and thick materials. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0032] Figure 1 The auxiliary feeding device for thin and thick materials provided by the present application is shown in the structural schematic view.

[0033] Figure 2 The auxiliary feeding device for thin and thick materials provided by the present application is shown in the structural schematic view. Figure 1 The auxiliary feeding device for thin and thick materials provided by the present application is shown in the structural schematic view.

[0034] Figure 3 The auxiliary feeding device for thin and thick materials provided by the present application is shown in the structural schematic view.

[0035] Figure 4 The auxiliary feeding device for thin and thick materials provided by the present application is shown in the structural schematic view.

[0036] Figure 5 For Figure 4 Another perspective structural diagram.

[0037] Reference signs:

[0038] 1 - mounting bracket;

[0039] 2 - one-way clutch drive assembly, 21 - one-way clutch drive star wheel shaft, 22 - driven shaft, 23 - bearing cover, 24 - driving gear, 25 - driven gear, 26 - bearing mounting seat, 27 - driving swing lever, 28 - housing;

[0040] 3 - belt drag wheel assembly, 31 - drag wheel mounting plate, 32 - driving wheel, 33 - first synchronous pulley, 34 - second synchronous pulley, 35 - synchronous belt, 36 - tensioning assembly, 361 - tensioning wheel, 362 - tensioning connecting rod, 363 - tensioning spring, 37 - drag wheel lifting and pressing connecting rod, 38 - driving source, 39 - supporting pin shaft;

[0041] 4 - roller compression spring;

[0042] 5 - one-way stop roller. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0044] In the utility model, unless explicitly defined and limited, the terms such as'mounting', 'connection', 'connecting', 'fixing' and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0045] The core of the utility model is to provide a kind of auxiliary feeding device of thin thick material, and thin material thick material sewing can have greater cloth feeding force, reach the purpose of thin thick material generalization. Another core of the utility model is to provide a sewing machine comprising the auxiliary feeding device of thin thick material generalization described above, which can improve the sewing performance of the sewing machine and improve the versatility of the sewing machine.

[0046] Please refer to Figure 1 ,Figure 2 and Figure 3 The auxiliary feeding device for thin and thick materials comprises a mounting bracket 1, a one-way clutch driving assembly 2 and a belt drag wheel assembly 3.

[0047] Specifically, the one-way clutch driving assembly 2 comprises a one-way clutch driving star wheel shaft 21 and a driven shaft 22, one end of the one-way clutch driving star wheel shaft 21 is connected with a driving gear 24 through a bearing and a bearing cover 23, the driving gear 24 is synchronously rotated by the rotation of the one-way clutch driving star wheel shaft 21, the driven shaft 22 is provided with a driven gear 25 which is in meshing transmission with the driving gear 24, the driven shaft 22 is rotated by the meshing transmission between the driving gear 24 and the driven gear 25, both ends of the one-way clutch driving star wheel shaft 21 and the driven shaft 22 are installed in bearing mounting seats 26 on the mounting plate to realize the positioning of the one-way clutch driving assembly 2, the belt drag wheel assembly 3 is connected with the driven shaft 22, the belt drag wheel assembly 3 is rotated by the driven shaft 22, thereby providing the drag force for sewing thin and thick materials, and the contact area between the sewing material and the drag wheel can be increased to ensure the smoothness of the whole sewing process, the flatness of the material and the uniformity and beauty of the sewing line, the number of teeth of the driving gear 24 is less than that of the driven gear 25, so that the speed reduction transmission can obtain greater torque, the drag force can be increased, and the thin and thick materials can be used universally.

[0048] In the embodiment, the gear ratio of the driving gear 24 to the driven gear 25 is 3 / 4, but in actual application, this is not limited as long as the effect of speed reduction is achieved.

[0049] The auxiliary feeding device for thin and thick materials arranged in the above manner can realize speed reduction transmission to obtain greater torque, the drag force can be increased, the thin and thick materials can be used universally, and after the speed reduction transmission by the gears, the drag wheel has a larger speed reduction interval, the adjustable interval of the drag amount is increased, and the sewing with the minimum needle spacing of 1.5 mm can be performed.

[0050] In the above embodiment, one end of the one-way clutch driving star wheel shaft 21 is connected with one end of a driving swing rod 27, the other end of the driving swing rod 27 is connected with one end of a connecting rod through a shaft pin, the other end of the connecting rod is connected with an adjusting swing rod connected with a main shaft.

[0051] It should be noted that the adjusting swing rod is driven to rotate by the main shaft, the connecting rod and the driving swing rod 27 are driven to rotate, the one-way clutch driving star wheel shaft 21 is driven to rotate around the axis direction thereof, the driving gear 24 is synchronously rotated, the driven shaft 22 is rotated by the meshing transmission between the driving gear 24 and the driven gear 25, the belt drag wheel assembly 3 is rotated by the driven shaft 22, and the feeding process is realized.

[0052] The one-way clutch star wheel shaft can be replaced by a motor to drive the belt drag wheel assembly 3.

[0053] In the above case, the driving gear 24 is provided with a shell 28, and the cavity formed between the shell 28 and the bearing cover 23 is provided with the roller compression spring 4 and the one-way stop roller 5. The roller compression spring 4 is arranged on the star wheel of the one-way clutch driving star wheel shaft 21, and the one-way stop roller 5 is connected with the roller compression spring 4.

[0054] It can be understood that the bearing cover 23 is sleeved on the star wheel of the one-way clutch driving star wheel shaft 21, and the cavity formed by the bearing cover 23 and the shell 28 of the driving gear 24 is provided with the roller compression spring 4 and the one-way stop roller 5. One end of the roller compression spring 4 is arranged on the spring seat on the star wheel, and the other end is tightly pressed against the one-way stop roller 5. The one-way stop roller 5 is tightly pressed between the inner wall of the bearing cover 23 and the shell 28 and the star wheel. Both ends of the one-way clutch driving star wheel shaft 21 are arranged on the mounting bracket 1 through bearings and bearing mounting seats 26.

[0055] Among them, the bearing can adopt ordinary bearing and anti-reverse one-way bearing, which is not limited.

[0056] Further, both ends of the one-way clutch driving star wheel shaft 21 are provided with oil seals and spacer washers.

[0057] It should be noted that the one-way clutch star wheel is sealed and lubricated by the spacer washers, oil seals and bearings arranged at both ends of the star wheel to form a self-sealing lubrication wedge-shaped star wheel one-way clutch driving structure. The one-way clutch star wheel is sealed and lubricated by grease, which has better durability and stability than the wheel-type tow wheel which cannot be lubricated.

[0058] Please refer to Figure 4 and Figure 5 The belt tow wheel assembly 3 includes a tow wheel mounting plate 31, a driving wheel 32, a first synchronous pulley 33, a second synchronous pulley 34, and a synchronous belt 35. The tow wheel mounting plate 31 is fixed to the mounting bracket 1. The driving wheel 32 is connected with the driven shaft 22. The first synchronous pulley 33 is movably mounted on the tow wheel mounting plate 31 through a first synchronous pulley shaft. The second synchronous pulley 34 is movably connected with the tow wheel lifting and pressing connecting rod 37 through a second synchronous pulley shaft. The synchronous belt 35 is wound around the outer periphery of the driving wheel 32, the first synchronous pulley 33, and the second synchronous pulley 34.

[0059] It can be understood that the driving wheel 32 is driven to rotate by the driven shaft 22, the first synchronous pulley 33 and the second synchronous pulley 34 are synchronously driven to rotate by the synchronous belt 35, and the tow cloth force is provided by the rotation of the synchronous belt 35. The contact area between the sewn fabric and the tow wheel can be increased, and the entire sewing process can be smooth, the fabric can be flat, and the stitches can be uniform and beautiful.

[0060] The one-way clutch drive star wheel shaft 21 and the driven shaft 22 are arranged on the mounting bracket 1 through bearings and bearing mounting seats 26, the mounting bracket 1 is arranged on the propeller shaft mounting plate 31, and the driven shaft 22 is connected with the driving wheel 32 through the mounting bracket 1 and the propeller shaft mounting plate 31. In the embodiment, the mounting bracket 1 is an L-shaped plate, but in actual application, the mounting bracket 1 is not limited to be an L-shaped plate.

[0061] On the basis of the above embodiment, the outer side of the synchronous belt 35 is provided with a tensioning assembly 36 for tensioning the synchronous belt 35.

[0062] It should be noted that the tensioning degree of the synchronous belt 35 is adjusted by arranging the tensioning assembly 36.

[0063] In the above embodiment, the tensioning assembly 36 comprises a tensioning wheel 361, a tensioning connecting rod 362 and a tensioning spring 363, the tensioning wheel 361 is arranged on the outer side of the synchronous belt 35, the first end of the tensioning connecting rod 362 is movably connected with the propeller shaft mounting plate 31, the second end of the tensioning connecting rod 362 is movably connected with the intermediate shaft of the tensioning wheel 361, the first end of the tensioning spring 363 is connected with the second end of the tensioning connecting rod 362 through a tensioning spring 363 pin, and the second end of the tensioning spring 363 is connected with the first end of the propeller shaft lifting and pressing connecting rod 37 through a tensioning spring 363 pin.

[0064] It can be understood that the tensioning wheel 361 for tensioning the synchronous belt 35 is arranged on the synchronous belt 35, the tensioning wheel 361 is connected with the tensioning connecting rod 362 arranged on the propeller shaft mounting plate 31 through a tensioning wheel 361 shaft pin, the tensioning connecting rod 362 and the propeller shaft lifting and pressing connecting rod 37 are both provided with a tensioning spring 363 pin, and the two are connected through the tensioning spring 363, the tensioning spring 363 is deformed to drive the tensioning connecting rod 362 to swing when the propeller shaft lifting and pressing connecting rod 37 swings, the tensioning connecting rod 362 drives the tensioning wheel 361 to rotate, and the synchronous belt 35 is compressed or relaxed.

[0065] Further, the belt propeller assembly 3 further comprises a driving source 38, the driving source 38 is arranged on the propeller shaft mounting plate 31, the output end of the driving source 38 is movably connected with the first end of the propeller shaft lifting and pressing connecting rod 37, the second end of the propeller shaft lifting and pressing connecting rod 37 is movably connected with the second synchronous wheel shaft, and the middle part of the propeller shaft lifting and pressing connecting rod 37 is movably connected with the propeller shaft mounting plate 31 through a supporting pin shaft 39, so that the driving source 38 drives the propeller shaft lifting and pressing connecting rod 37 to perform deflection movement in the extension and retraction movement.

[0066] It needs to be explained that the second synchronous pulley shaft is connected with one end of the tow pulley lifting and pressing connecting rod 37 through a screw, the other end of the tow pulley lifting and pressing connecting rod 37 is connected with a movable rod of a driver, the driver is arranged on the tow pulley mounting plate 31, the movable rod of the driver drives the tow pulley lifting and pressing connecting rod 37 to swing around a supporting shaft pin arranged on the tow pulley mounting plate 31, and the second synchronous belt pulley 34 is driven to be lifted and lowered. At the same time, the movable rod of the driver drives the tow pulley lifting and pressing connecting rod 37 to swing when working, the tensioning spring 363 is deformed to drive the tensioning connecting rod 362 to swing, the tensioning connecting rod 362 drives the tensioning wheel 361 to rotate, and the pressing or loosening of the belt tow pulley is realized.

[0067] In the above case, the driving source 38 is provided with a connecting seat, and the connecting seat is fixed to the tow pulley mounting plate 31 through a limiting pin.

[0068] It can be understood that the limiting and fixing of the driving source 38 are realized through the cooperation of the connecting seat and the limiting pin. In the embodiment, the driving source 38 is preferably a pneumatic cylinder, but in actual application, this is not limited, as long as the above technical effects can be achieved.

[0069] In the above embodiment, the movable rod of the driving source 38 is provided with a connecting piece and an adjusting nut for limiting the position of the connecting piece, and the connecting piece is movably connected with the first end of the tow pulley lifting and pressing connecting rod 37.

[0070] It needs to be explained that the adjusting nut is sleeved on the movable rod of the driving source 38, the position of the adjusting nut on the movable rod is adjusted, the maximum stroke of the movable rod is adjusted, the maximum swing amplitude of the tow pulley lifting and pressing connecting rod 37 is limited, and the adjustable fabric pressing force is realized.

[0071] In summary, the auxiliary feeding device for thin and thick materials provided by the utility model increases the contact area between the sewing fabric and the tow pulley, greatly reduces the spacing between the tow pulley and the feeding teeth during installation, has better tow force when sewing thin and thick materials, the driving gear 24 and the driven gear 25 are deceleration transmission, greater torque is obtained, the tow force is increased, the thin and thick materials are universal, and the whole sewing process is smooth, the fabric is flat, and the sewing line is uniform and beautiful.

[0072] In addition to the auxiliary feeding device for thin and thick materials disclosed in the above various embodiments, the utility model also provides a sewing machine comprising the auxiliary feeding device for thin and thick materials, and the structures of other parts of the sewing machine refer to the prior art, and will not be described herein.

[0073] It needs to be explained that in the specification, the relationship terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply any actual relationship or order between the entities.

[0074] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0075] The above describes in detail the auxiliary feeding device and sewing machine provided by the utility model. The principle and implementation mode of the utility model are described by applying specific examples. The above description of the embodiments is only used to help understand the method and core idea of the utility model. It should be pointed out that the ordinary skilled in the art can make some improvements and modifications to the utility model without departing from the principle of the utility model. These improvements and modifications also fall within the protection scope of the utility model claims.

Claims

1. A universal auxiliary feeding device for thin and thick materials, characterized in that, include: Mounting bracket (1); One-way clutch drive assembly (2), the one-way clutch drive assembly (2) includes a one-way clutch drive star wheel shaft (21) and a driven shaft (22). One end of the one-way clutch drive star wheel shaft (21) is connected to the drive gear (24) through a bearing and a bearing cover (23). The driven shaft (22) is provided with a driven gear (25) that meshes with the drive gear (24). The number of teeth of the drive gear (24) is less than the number of teeth of the driven gear (25). Both ends of the one-way clutch drive star wheel shaft (21) and the driven shaft (22) are mounted on a bearing mounting seat (26). The bearing mounting seat (26) is fixed to the mounting bracket (1). The belt pulley assembly (3) is connected to the driven shaft (22).

2. The universal auxiliary feeding device for thin and thick materials according to claim 1, characterized in that, One end of the one-way clutch drive star wheel shaft (21) is connected to one end of the drive rocker arm (27), the other end of the drive rocker arm (27) is connected to one end of the connecting rod through a shaft pin, and the other end of the connecting rod is connected to the adjusting rocker arm connected to the main shaft.

3. The universal auxiliary feeding device for thin and thick materials according to claim 1, characterized in that, The drive gear (24) is provided with a housing (28). A roller compression spring (4) and a one-way stop roller (5) are provided in the cavity formed between the housing (28) and the bearing cover (23). The roller compression spring (4) is provided on the star wheel of the one-way clutch drive star wheel shaft (21). The one-way stop roller (5) is connected to the roller compression spring (4).

4. The universal auxiliary feeding device for thin and thick materials according to claim 1, characterized in that, Both ends of the one-way clutch drive star wheel shaft (21) are equipped with oil seals and spacer gaskets.

5. The universal auxiliary feeding device for thin and thick materials according to claim 1, characterized in that, The belt pulley assembly (3) includes: A tow wheel mounting plate (31) is fixed to the mounting bracket (1). The driving wheel (32) is connected to the driven shaft (22); The first synchronous pulley (33) is movably mounted on the trolley mounting plate (31) via the first synchronous pulley shaft. The second synchronous pulley (34) is movably connected to the trolley lifting linkage (37) via the second synchronous pulley shaft. A timing belt (35) is wound around the outer periphery of the drive pulley (32), the first timing pulley (33), and the second timing pulley (34).

6. The universal auxiliary feeding device for thin and thick materials according to claim 5, characterized in that, The outer side of the timing belt (35) is provided with a tensioning component (36) for tensioning the timing belt (35).

7. The universal auxiliary feeding device for thin and thick materials according to claim 6, characterized in that, The tensioning assembly (36) includes: The tension pulley (361) is located on the outside of the synchronous belt (35); Tensioning link (362), the first end of which is movably connected to the towing wheel mounting plate (31), and the second end of which is movably connected to the intermediate shaft of the tensioning wheel (361); The tension spring (363) has its first end connected to the second end of the tensioning link (362) via a tension spring pin, and the second end of the tension spring (363) is connected to the first end of the towing wheel lifting link (37) via the tension spring (363) pin.

8. The universal auxiliary feeding device for thin and thick materials according to claim 5, characterized in that, The belt drag wheel assembly (3) further comprises a driving source (38) arranged on the drag wheel mounting plate (31), an output end of the driving source (38) movably connected with a first end of the drag wheel lifting and pressing connecting rod (37), a second end of the drag wheel lifting and pressing connecting rod (37) movably connected with the second synchronous wheel shaft, and a middle part of the drag wheel lifting and pressing connecting rod (37) movably connected with the drag wheel mounting plate (31) through a supporting pin shaft (39), so that the driving source (38) drives the drag wheel lifting and pressing connecting rod (37) to perform a deflection movement in a telescopic movement.

9. The universal auxiliary feeding device for thin and thick materials according to claim 8, characterized in that, The driving source (38) is provided with a connecting seat fixed to the drag wheel mounting plate (31) through a limiting pin.

10. The universal auxiliary feeding device for thin and thick materials according to claim 9, characterized in that, A connecting piece and an adjusting nut for limiting the position of the connecting piece are arranged on a movable rod of the driving source (38), and the connecting piece is movably connected with the first end of the drag wheel lifting and pressing connecting rod (37).

11. A sewing machine characterized by comprising: The auxiliary feeding device is universal for thin and thick materials.

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