Feeding system for a sewing machine

Abstract

The utility model provides a kind of feeding system of sewing machine, belong to sewing machine technical field.It solves the technical problems such as the additional driving source required by existing cloth feeding mechanism, complex structure, poor synchronism of cloth feeding and needle action.The feeding system of this sewing machine includes driving shaft, needle feeding assembly and cloth feeding assembly, driving shaft is rotatably installed on head, driving member for driving driving shaft reciprocating rotation is arranged in head, needle feeding assembly and cloth feeding assembly are connected with driving shaft, when needle of needle feeding assembly is under cloth, cloth feeding assembly stops cloth feeding, after needle of needle feeding assembly moves up and separates from cloth, cloth feeding assembly starts cloth feeding, cloth feeding assembly is connected with driving shaft by transmission assembly.The utility model drives needle feeding assembly and cloth feeding assembly simultaneously by setting single driving shaft, realizes the accurate synchronization of needle action and cloth feeding action.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology, and specifically refers to a feeding system for a sewing machine. Background Technology

[0002] Overlock sewing machines are widely used in clothing, home textiles, and other fields to overlock the edges of fabrics, enhancing their appearance and durability. Traditional overlock sewing machines often use a presser foot to tighten the fabric during feeding, which can easily leave indentations on the fabric surface, affecting the quality of the finished product.

[0003] To address the aforementioned problems, various improvement solutions have been proposed in the prior art. For example, prior art document CN222878259U discloses a fabric feeding mechanism for an overlock sewing machine. This mechanism achieves unidirectional fabric feeding by setting up upper and lower feed wheels and unidirectional needle roller bearings, and drives the feed wheels to rotate through a crank-connecting rod mechanism, thereby avoiding, to some extent, the problem of fabric wrinkles or creases caused by inconsistent linear speeds of the upper and lower feed wheels.

[0004] However, the feeding mechanism still has the following shortcomings: the upper end of its connecting rod is connected to a separate drive shaft, which requires an additional drive source, resulting in a complex overall structure and high cost. Furthermore, its synchronization with the needle movement is poor, and it is easy to affect the sewing accuracy due to transmission errors. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a feeding system that does not require an additional driving source, has a simpler structure, and higher precision.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A feeding system for a sewing machine, characterized in that it includes a drive shaft, a needle feeding assembly, and a fabric feeding assembly. The drive shaft is rotatably mounted on the machine head, and a drive component that drives the drive shaft to reciprocate is provided inside the machine head. The needle feeding assembly and the fabric feeding assembly are both connected to the drive shaft. When the needle of the needle feeding assembly passes through the fabric, the fabric feeding assembly stops feeding the fabric. After the needle of the needle feeding assembly moves upward and leaves the fabric, the fabric feeding assembly starts feeding the fabric. The fabric feeding assembly is connected to the drive shaft through a transmission assembly.

[0008] This feeding system uses a single drive shaft to simultaneously drive both the needle feeding assembly and the fabric feeding assembly, achieving precise synchronization between needle movement and fabric feeding. When the needle penetrates the fabric, the fabric feeding assembly stops feeding, preventing interference between the needle and fabric and ensuring sewing accuracy. When the needle moves upwards and leaves the fabric, the fabric feeding assembly begins feeding, ensuring timely and stable fabric feeding. This integrated drive method reduces the need for additional drive sources, simplifies the overall structure, lowers manufacturing costs, and simultaneously improves the reliability and sewing quality of the sewing machine.

[0009] In the aforementioned feeding system of a sewing machine, the transmission assembly includes a mounting base, a rocker arm crank, a rocker arm connecting rod, a rocker arm rocker arm, a transmission shaft, a transmission crank, and a transmission connecting rod.

[0010] The needle arm of the needle feeding assembly is connected to the end of the drive shaft and swings with the drive shaft.

[0011] The rocker arm crank is fixedly connected to the drive shaft and swings with the drive shaft.

[0012] The mounting base is fixedly connected to the sleeve, the sleeve is sleeved on the drive shaft and fixedly connected to the machine head, and the drive shaft can rotate relative to the mounting base.

[0013] The drive shaft is rotatably mounted on the mounting base and parallel to the drive shaft.

[0014] The rocker arm is fixedly connected to one end of the drive shaft, and the drive crank is fixedly connected to the other end of the drive shaft.

[0015] The swing arm crank and the swing arm rocker are connected by a swing arm connecting rod, the transmission crank is hinged to the transmission connecting rod, and the transmission connecting rod is connected to the fabric feeding mechanism.

[0016] Through the design of the aforementioned transmission components, this feeding system efficiently transmits the reciprocating rotation of the drive shaft to the fabric feeding assembly, ensuring coordination between the fabric feeding action and the needle movement. The cooperation of the swing arm crank, swing arm connecting rod, and swing arm rocker converts the oscillation of the drive shaft into the rotation of the transmission shaft, which then drives the fabric feeding mechanism via the transmission crank and connecting rod, achieving smooth and precise power transmission. This transmission method is compact, reduces clearance and errors between moving parts, improves the accuracy of the fabric feeding sequence, and thus enhances the overall performance of the sewing machine.

[0017] The aforementioned needle mechanism includes a needle crank, a needle swing arm, a needle mounting rod, and a needle body. The needle body is fixed to the lower end of the needle mounting rod. One end of the needle swing arm is connected to the needle mounting rod and can drive the needle mounting rod to move up and down. The other end is rotatably connected to the needle crank. The needle crank is fixedly connected to the drive shaft.

[0018] In the feeding system of the sewing machine described above, one end of the swing arm crank is sleeved on the drive shaft and fixedly connected to the drive shaft by screws or bolts, and the other end of the swing arm crank is provided with a long strip-shaped first adjustment hole. One end of the swing arm connecting rod is adjustablely connected to the swing arm crank by an adjustment bolt passing through the first adjustment hole.

[0019] The first adjustment hole on the swing arm crank of this feeding system allows for adjustment of the connection position of the swing arm connecting rod via the adjusting bolt, thereby fine-tuning the movement amplitude of the transmission components. This adjustable design enables users to flexibly adjust the feed amount or needle action sequence according to different sewing needs, enhancing the adaptability and versatility of the sewing machine, while simplifying the debugging process and improving production efficiency.

[0020] In the feeding system of the sewing machine described above, the swing arm connecting rod is connected to the upper part of the swing arm rocker arm, and the transmission connecting rod is hinged to the lower end of the transmission crank.

[0021] This feeding system connects the swing arm connecting rod to the upper part of the swing arm rocker arm, and hinges the transmission connecting rod to the lower end of the transmission crank. This layout optimizes the force transmission path, making the transmission process more balanced and stable, reducing vibration and impact during movement, ensuring smooth fabric feeding, and further improving sewing accuracy and machine life. It also prevents interference between the transmission connecting rod and transmission crank and the swing arm crank, swing arm connecting rod, and swing arm rocker arm during swinging, increasing the stability of the feeding system during operation. Furthermore, this technical solution aims to ensure that the connection point between the swing arm connecting rod and the swing arm rocker arm is opposite in direction to the connection point between the transmission connecting rod and the transmission crank. Therefore, the lower connection of the swing arm connecting rod to the swing arm rocker arm and the upper hinge of the transmission connecting rod to the transmission crank should be considered equivalent to this solution and should also fall within the protection scope of this solution.

[0022] In the feeding system of the sewing machine described above, the drive shaft reciprocates within a 60° sector range.

[0023] The drive shaft of this feeding system reciprocates within a 60° sector range. This design limits the range of motion of the drive shaft, avoiding energy loss and mechanical wear caused by excessive rotation. Simultaneously, this limited range of motion ensures precise control of the needle and fabric feeding actions, improves motion efficiency, reduces the load on the drive components, and extends service life. Preferably, the rotation angle of the drive shaft is 30°.

[0024] In the above-mentioned feeding system of a sewing machine, the fabric feeding assembly includes an upper support, a lower support, and an upper feed wheel and a lower feed wheel arranged in parallel. The fabric passes through the gap between the upper feed wheel and the lower feed wheel. An upper rotating shaft is rotatably mounted on the upper support, and an upper feed wheel is sleeved on the upper rotating shaft. The upper rotating shaft and the upper feed wheel are connected by an upper one-way needle roller bearing.

[0025] One end of the upper rotating shaft extends out of the upper bracket and is fixedly connected to the middle of the upper crank. The upper end of the upper crank is hinged to the lower end of the transmission connecting rod, and the lower end of the upper crank is connected to the upper end of the lower crank.

[0026] A lower rotating shaft is rotatably mounted on the lower support, and a lower feed wheel is sleeved on the lower rotating shaft. The lower rotating shaft and the lower feed wheel are connected by a lower one-way needle roller bearing. The lower end of the lower crank is fixedly connected to the fixing sleeve of the lower rotating shaft or the lower one-way needle roller bearing. An elongated hole is provided on the lower crank, and the length direction of the elongated hole is parallel to the length direction of the lower crank. A connecting piece is installed at the lower end of the upper crank, and the connecting piece can slide back and forth along the elongated hole. The upper feed wheel and the lower feed wheel have opposite rotational directions.

[0027] The fabric feeding component in this feeding system adopts an upper and lower feed roller design with one-way needle roller bearings, ensuring that the fabric only moves forward during the feeding process, avoiding wrinkles or creases caused by the different linear speeds of the upper and lower feed rollers. The upper and lower cranks are slidably connected through elongated holes and connectors, realizing synchronous drive of the upper and lower feed rollers, making the fabric feeding more stable. At the same time, this component is linked with the drive shaft through a transmission component, ensuring precise coordination between the fabric feeding action and the needle action, further improving the quality and aesthetics of the hemming.

[0028] In the feeding system of the sewing machine described above, a presser foot is fixedly connected to the front side of the upper support, and an adjusting rod is fixedly connected to the upper end of the upper support. The adjusting rod passes through the machine head and extends out from the upper end of the machine head. An adjusting nut is threaded to the upper end of the adjusting rod, and the height of the upper support can be adjusted by rotating the adjusting nut.

[0029] The aforementioned presser foot design ensures the fabric is positioned correctly during sewing. The height of the upper support can be easily adjusted using the adjusting rod and nut to accommodate fabrics of varying thicknesses. This adjustment mechanism avoids the indentations caused by excessive pressure applied to the fabric by traditional presser feet, improving the aesthetics of the finished product. Once adjusted, the height is fixed, ensuring pressure stability throughout the sewing process and guaranteeing product consistency.

[0030] In the feeding system of the sewing machine described above, both the upper and lower one-way needle roller bearings include a fixed sleeve and an outer ring. The fixed sleeve is fixedly connected to the corresponding upper or lower rotating shaft. The fixed sleeve and the outer ring are rotatably connected in one direction. The outer ring is tightly fitted to the corresponding upper and lower feed wheels.

[0031] The fixed sleeve and outer ring of the aforementioned one-way needle roller bearing are rotatably connected in one direction, ensuring that the upper and lower feed rollers can only rotate in a specific direction. This reliably drives the fabric forward and allows it to idle freely during reverse movement, preventing fabric backflow or stress. This design improves the controllability and stability of fabric feeding and reduces the failure rate.

[0032] In the feeding system of the sewing machine described above, small protrusions are evenly distributed on the outer circumferential surfaces of the upper feed wheel and the lower feed wheel.

[0033] The small protrusions on the outer circumference of the upper and lower feed wheels increase the friction between the feed wheels and the fabric, ensuring that the fabric will not slip during feeding and making the fabric transport smoother and more reliable.

[0034] Compared with the prior art, the technical effects of this utility model are as follows:

[0035] Through the design of the aforementioned transmission components, this invention enables the reciprocating rotation of the drive shaft to be efficiently transmitted to the fabric feeding component, ensuring coordination between the fabric feeding action and the needle action.

[0036] In this invention, the cooperation of the swing arm crank, swing arm connecting rod, and swing arm rocker converts the swing of the drive shaft into the rotation of the transmission shaft, and then drives the fabric feeding mechanism through the transmission crank and transmission connecting rod, thus achieving smooth and precise power transmission. This transmission method has a compact structure, reduces the gaps and errors between moving parts, improves the accuracy of the fabric feeding sequence, and thus enhances the overall performance of the sewing machine. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0038] Figure 2 This is a schematic diagram of the transmission component of this utility model. Figure 1 .

[0039] Figure 3 This is a schematic diagram of the transmission component of this utility model. Figure 2 .

[0040] Figure 4 This is a schematic diagram of the needle feeding assembly of this utility model.

[0041] Figure 5 This is a schematic diagram of the fabric feeding assembly of this utility model.

[0042] Figure 6 This is a cross-sectional view of the fabric feeding assembly of this utility model. Figure 1 .

[0043] Figure 7 This is a cross-sectional view of the fabric feeding assembly of this utility model. Figure 2 .

[0044] Figure 8 This is an exploded structural diagram of the upper feed wheel of this utility model.

[0045] Figure 9 This is an exploded structural diagram of the lower feed wheel of this utility model.

[0046] Figure 10 This is a schematic diagram showing the rotation direction of each component when the transmission linkage of this utility model moves forward.

[0047] Figure 11 This is a schematic diagram showing the rotation direction of each component when the transmission linkage of this utility model moves backward.

[0048] In the diagram, 1. Drive shaft; 2. Transmission assembly; 21. Mounting base; 211. Sleeve; 22. Swing arm crank; 221. First adjusting hole; 23. Swing arm connecting rod; 231. Adjusting bolt; 24. Swing arm rocker arm; 25. Transmission shaft; 26. Transmission crank; 27. Transmission connecting rod; 3. Fabric feeding assembly; 31. Upper bracket; 311. Upper feed wheel; 312. Upper rotating shaft; 313. Upper one-way needle roller bearing; 314. Upper... 32. Crank; 32. Lower support; 321. Lower feed wheel; 322. Lower shaft; 323. Lower one-way needle roller bearing; 324. Lower crank; 325. Long slot; 326. Connector; 33. Presser foot; 34. Adjusting rod; 35. Adjusting nut; 36. Fixing sleeve; 37. Outer ring; 38. Small protrusion; 4. Needle feed assembly; 41. Needle crank; 42. Needle swing arm; 43. Needle mounting rod; 44. Needle body. Detailed Implementation

[0049] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0050] The feeding system of this sewing machine includes a drive shaft 1, a needle feeding assembly 4, and a fabric feeding assembly 3. The drive shaft 1 is rotatably mounted on the machine head, and a drive component is installed inside the machine head to drive the drive shaft 1 to reciprocate. Both the needle feeding assembly 4 and the fabric feeding assembly 3 are connected to the drive shaft 1. When the needle of the needle feeding assembly 4 passes through the fabric, the fabric feeding assembly 3 stops feeding fabric. After the needle of the needle feeding assembly 4 moves upward and leaves the fabric, the fabric feeding assembly 3 starts feeding fabric. The fabric feeding assembly 3 is connected to the drive shaft 1 through a transmission assembly 2. This feeding system achieves precise synchronization between the needle movement and the fabric feeding movement by using a single drive shaft 1 to simultaneously drive the needle feeding assembly 4 and the fabric feeding assembly 3. When the needle passes through the fabric, the fabric feeding assembly 3 stops feeding fabric, avoiding interference between the needle and the fabric and ensuring sewing accuracy; when the needle moves upward and leaves the fabric, the fabric feeding assembly 3 starts feeding fabric, ensuring timely and stable fabric feeding. This integrated drive method reduces the need for additional drive sources, simplifies the overall structure, lowers manufacturing costs, and improves the reliability and sewing quality of the sewing machine.

[0051] like Figure 2 and Figure 3 As shown, the transmission assembly 2 includes a mounting base 21, a swing arm crank 22, a swing arm connecting rod 23, a swing arm rocker arm 24, a transmission shaft 25, a transmission crank 26, and a transmission connecting rod 27. The needle swing arm 42 of the needle feeding assembly 4 is connected to the end of the drive shaft 1 and swings with the drive shaft 1. The swing arm crank 22 is fixedly connected to the drive shaft 1 and swings with the drive shaft 1. The mounting base 21 is fixedly connected to the sleeve 211. The sleeve 211 is sleeved on the drive shaft 1 and fixedly connected to the machine head. The drive shaft 1 can rotate relative to the mounting base 21. The transmission shaft 25 is rotatably mounted on the mounting base 21 and parallel to the drive shaft 1. The swing arm rocker arm 24 is fixedly connected to one end of the transmission shaft 25. The transmission crank 26 is fixedly connected to the other end of the transmission shaft 25. The swing arm crank 22 and the swing arm rocker arm 24 are connected through the swing arm connecting rod 23. The transmission crank 26 is hinged to the transmission connecting rod 27. The transmission connecting rod 27 is connected to the fabric feeding mechanism. Through the design of the aforementioned transmission component 2, this feeding system efficiently transmits the reciprocating rotation of the drive shaft 1 to the fabric feeding component 3, ensuring coordination between the fabric feeding action and the needle action. The cooperation of the swing arm crank 22, swing arm connecting rod 23, and swing arm rocker 24 converts the oscillation of the drive shaft 1 into the rotation of the transmission shaft 25, which then drives the fabric feeding mechanism through the transmission crank 26 and transmission connecting rod 27, achieving smooth and precise power transmission. This transmission method has a compact structure, reduces the gaps and errors between moving parts, improves the accuracy of the fabric feeding sequence, and thus enhances the overall performance of the sewing machine.

[0052] like Figure 4As shown, the needle mechanism includes a needle crank 41, a needle swing arm 42, a needle mounting rod 43, and a needle body 44. The needle body 44 is fixed to the lower end of the needle mounting rod 43. One end of the needle swing arm 42 is connected to the needle mounting rod 43 and can drive the needle mounting rod 43 to move up and down. The other end is rotatably connected to the needle crank 41. The needle crank 41 is fixedly connected to the drive shaft 1.

[0053] Furthermore, one end of the swing arm crank 22 is sleeved on the drive shaft 1 and fixedly connected to the drive shaft 1 by screws or bolts. The other end of the swing arm crank 22 is provided with a long strip-shaped first adjustment hole 221. One end of the swing arm connecting rod 23 is adjustablely connected to the swing arm crank 22 by an adjusting bolt 231 passing through the first adjustment hole 221. The first adjustment hole 221 provided on the swing arm crank 22 of this feeding system allows the connection position of the swing arm connecting rod 23 to be adjusted by adjusting the adjusting bolt 231, thereby fine-tuning the movement amplitude of the transmission component 2. This adjustable design allows users to flexibly adjust the fabric feed or needle action sequence according to different sewing needs, enhancing the adaptability and versatility of the sewing machine, while simplifying the debugging process and improving production efficiency.

[0054] Preferably, the upper part of the swing arm connecting rod 23 is connected to the upper part of the swing arm rocker arm 24, and the lower end of the transmission connecting rod 27 is hinged to the lower end of the transmission crank 26. This feeding system connects the swing arm connecting rod 23 to the upper part of the swing arm rocker arm 24 and hinges the transmission connecting rod 27 to the lower end of the transmission crank 26. This layout optimizes the force transmission path, making the transmission process more balanced and stable, reducing vibration and impact during movement, ensuring smooth fabric feeding, and further improving sewing accuracy and machine life. Simultaneously, it avoids interference between the transmission connecting rod 27, the transmission crank 26, and the swing arm crank 22, the swing arm connecting rod 23, and the swing arm rocker arm 24 during swinging, increasing the stability of the feeding system during operation. Furthermore, the main purpose of this technical solution is to make the connection point between the rocker arm connecting rod 23 and the rocker arm rocker 24 and the connection point between the transmission connecting rod 27 and the transmission crank 26 opposite in direction. Therefore, the lower connection between the rocker arm connecting rod 23 and the rocker arm rocker 24 and the upper hinge of the transmission connecting rod 27 and the transmission crank 26 should be considered equivalent to this solution and should also fall within the protection scope of this solution.

[0055] Preferably, the drive shaft 1 reciprocates within a 60° sector range. This 60° sector range design limits the range of motion of the drive shaft 1, avoiding energy loss and mechanical wear caused by excessive rotation. Simultaneously, this limited range of motion ensures precise control of the needle and fabric feeding actions, improves motion efficiency, reduces the load on the drive components, and extends their service life. Preferably, the rotation angle of the drive shaft 1 is 30°.

[0056] like Figure 5-11As shown, the fabric feeding assembly 3 includes an upper support 31, a lower support 32, and parallel upper feed rollers 311 and 321. The fabric passes through the gap between the upper feed rollers 311 and 321. An upper rotating shaft 312 is rotatably mounted on the upper support 31, and the upper feed rollers 311 are sleeved on the upper rotating shaft 312. The upper rotating shaft 312 and the upper feed rollers 311 are connected by an upper one-way needle roller bearing 313. One end of the upper rotating shaft 312 extends out of the upper support 31 and is fixedly connected to the middle of the upper crank 314. The upper end of the upper crank 314 is hinged to the lower end of the transmission connecting rod 27, and the lower end of the upper crank 314 is connected to the upper end of the lower crank 324. The lower support 32 is rotatably mounted with a lower rotating shaft 322, and a lower feed wheel 321 is sleeved on the lower rotating shaft 322. The lower rotating shaft 322 and the lower feed wheel 321 are connected by a lower one-way needle roller bearing 323. The lower end of the lower crank 324 is fixedly connected to the fixing sleeve 36 of the lower rotating shaft 322 or the lower one-way needle roller bearing 323. The lower crank 324 is provided with an elongated hole 325, the length direction of which is parallel to the length direction of the lower crank 324. The lower end of the upper crank 314 is equipped with a connector 326, which can slide back and forth along the elongated hole 325. The upper feed wheel 311 and the lower feed wheel 321 have opposite rotational directions. The fabric feeding component 3 in this feeding system adopts an upper and lower feed roller 321 with a one-way needle roller bearing design, which ensures that the fabric only moves forward during the feeding process, avoiding wrinkles or creases caused by the different linear speeds of the upper and lower feed rollers 321. The upper crank 314 and the lower crank 324 are slidably connected through the elongated hole 325 and the connector 326, realizing the synchronous drive of the upper and lower feed rollers 321, making the fabric feeding more stable. At the same time, this component is linked with the drive shaft 1 through the transmission component 2, ensuring the precise coordination between the fabric feeding action and the needle action, further improving the quality and aesthetics of the hemming sewing.

[0057] Furthermore, a presser foot 33 is fixedly connected to the front side of the upper support 31, and an adjusting rod 34 is fixedly connected to the upper end of the upper support 31. The adjusting rod 34 passes through the sewing head and extends from the upper end of the sewing head. An adjusting nut 35 is threadedly connected to the upper end of the adjusting rod 34. Rotating the adjusting nut 35 can adjust the height of the upper support 31. The aforementioned presser foot 33 ensures the positioning of the fabric during the sewing process. At the same time, the height of the upper support 31 can be easily adjusted through the adjusting rod 34 and the adjusting nut 35, thereby accommodating fabrics of different thicknesses. This adjustment mechanism avoids the indentations caused by excessive pressure applied to the fabric by the traditional presser foot 33, improving the aesthetics of the finished product. After adjustment, the height is fixed, ensuring the stability of pressure throughout the sewing process and guaranteeing product consistency.

[0058] Furthermore, both the upper one-way needle roller bearing 313 and the lower one-way needle roller bearing 323 include a fixed sleeve 36 and an outer ring 37. The fixed sleeve 36 is fixedly connected to the corresponding upper rotating shaft 312 or lower rotating shaft 322. The fixed sleeve 36 and the outer ring 37 are rotatably connected in one direction, and the outer ring 37 is tightly fitted to the corresponding upper feed wheel 311 and lower feed wheel 321. The rotatable connection of the fixed sleeve 36 and the outer ring 37 of the aforementioned one-way needle roller bearings ensures that the upper and lower feed wheels 321 can only rotate in a specific direction, thereby reliably driving the fabric forward and allowing it to idle freely during reverse movement, avoiding fabric backflow or stress. This design improves the controllability and stability of fabric feeding and reduces the failure rate.

[0059] Furthermore, small protrusions 38 are evenly distributed on the outer circumferential surfaces of the upper feed roller 311 and the lower feed roller 321. The small protrusions 38 on the outer circumferential surfaces of the upper and lower feed rollers 321 increase the friction between them and the fabric, ensuring that the fabric will not slip during the feeding process, making the fabric transport smoother and more reliable.

[0060] like Figure 10 As shown, when the transmission link 27 pushes the upper crank 314 to swing forward (as indicated by arrow A'), the upper crank 314 drives the upper shaft 312 and the fixed sleeve 36 to rotate clockwise (as indicated by arrow D'). Since the upper one-way needle roller bearing 313 is locked when the fixed sleeve 36 rotates clockwise relative to the outer ring 37, the outer ring 37 and the upper feed wheel 311 will rotate clockwise synchronously with the lower shaft 322 (as indicated by arrow C'); at the same time, forward... The swinging upper crank 314 drives the lower crank 324 to swing backward (as shown by arrow B'). The swinging lower crank 324 drives the lower shaft 322 and the fixed sleeve 36 to rotate counterclockwise (as shown by arrow F'). Since the lower one-way needle roller bearing 323 is locked when the fixed sleeve 36 rotates counterclockwise relative to the outer ring 37, the outer ring 37 and the lower feed wheel 321 will rotate counterclockwise synchronously with the lower shaft 322 (as shown by arrow E').

[0061] like Figure 11As shown, when the transmission link 27 pulls the upper crank 314 to swing backward (as indicated by arrow A"), the upper crank 314 drives the upper rotating shaft 312 and the fixed sleeve 36 to rotate counterclockwise (as indicated by arrow D). Since the upper one-way needle roller bearing 313 rotates smoothly and is not locked relative to the outer ring 37 in the counterclockwise direction of the fixed sleeve 36, the outer ring 37 and the upper feed wheel 311 will either remain stationary or rotate clockwise under the inertia of the fabric (as indicated by arrow C). At the same time, the upper crank 312 rotates backward. The swinging upper crank 314 drives the lower crank 324 to swing forward (as shown by arrow B”). The swinging lower crank 324 drives the lower shaft 322 and the fixed sleeve 36 to rotate clockwise (as shown by arrow F”). Since the lower one-way needle roller bearing 323 is smooth and not locked when the fixed sleeve 36 rotates clockwise relative to the outer ring 37, the outer ring 37 and the lower feed wheel 321 will either remain stationary or rotate counterclockwise due to the inertia of the fabric (as shown by arrow E”).

[0062] The above Figure 10 and Figure 11 Arrow O in the diagram indicates the direction of fabric movement.

[0063] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection defined by the claims of the present utility model.

Claims

1. A feed system for a sewing machine, characterized by: The device includes a drive shaft (1), a needle feeding assembly (4), and a fabric feeding assembly (3). The drive shaft (1) is rotatably mounted on the machine head. The machine head is equipped with a drive component that drives the drive shaft (1) to reciprocate. The needle feeding assembly (4) and the fabric feeding assembly (3) are both connected to the drive shaft (1). When the needle of the needle feeding assembly (4) passes through the fabric, the fabric feeding assembly (3) stops feeding the fabric. After the needle of the needle feeding assembly (4) moves up and leaves the fabric, the fabric feeding assembly (3) starts feeding the fabric. The fabric feeding assembly (3) is connected to the drive shaft (1) through a transmission assembly (2).

2. A thread feeding system for a sewing machine according to claim 1, characterized in that: In the feeding system of the sewing machine described above, the transmission assembly (2) includes a mounting base (21), a swing arm crank (22), a swing arm connecting rod (23), a swing arm rocker arm (24), a transmission shaft (25), a transmission crank (26), and a transmission connecting rod (27). The needle swing arm (42) of the needle feeding assembly (4) is connected to the end of the drive shaft (1) and swings with the drive shaft (1). The swing arm crank (22) is fixedly connected to the drive shaft (1) and swings with the drive shaft (1). The mounting base (21) is fixedly connected to the sleeve (211), and the sleeve (211) is sleeved on the drive shaft. The drive shaft (1) is fixedly connected to the machine head on the shaft (1). The drive shaft (1) can rotate relative to the mounting base (21). The transmission shaft (25) is rotatably mounted on the mounting base (21) and parallel to the drive shaft (1). The rocker arm (24) is fixedly connected to one end of the transmission shaft (25). The transmission crank (26) is fixedly connected to the other end of the transmission shaft (25). The rocker arm crank (22) and the rocker arm (24) are connected through the rocker arm connecting rod (23). The transmission crank (26) is hinged to the transmission connecting rod (27). The transmission connecting rod (27) is connected to the fabric feeding mechanism.

3. A thread feeding system for a sewing machine according to claim 2, characterized in that: One end of the swing arm crank (22) is sleeved on the drive shaft (1) and fixedly connected to the drive shaft (1) by screws or bolts. The other end of the swing arm crank (22) is provided with a long strip-shaped first adjustment hole (221). One end of the swing arm connecting rod (23) is adjustablely connected to the swing arm crank (22) by an adjustment bolt (231) passing through the first adjustment hole (221).

4. The thread feeding system of a sewing machine according to claim 2, wherein: The upper part of the swing arm connecting rod (23) is connected to the upper part of the swing arm rocker arm (24), and the lower end of the transmission connecting rod (27) is hinged to the lower end of the transmission crank (26).

5. The thread feeding system of a sewing machine according to claim 1, wherein: The drive shaft (1) reciprocates within a 60° sector range.

6. A thread feeding system for a sewing machine according to any one of claims 1-5, characterized in that: The fabric feeding assembly (3) includes an upper support (31), a lower support (32), and parallel upper feed wheel (311) and lower feed wheel (321). The fabric passes through the gap between the upper feed wheel (311) and the lower feed wheel (321). An upper rotating shaft (312) is rotatably mounted on the upper support (31), and the upper feed wheel (311) is sleeved on the upper rotating shaft (312). The upper rotating shaft (312) and the upper feed wheel (311) are connected by an upper one-way needle roller bearing (313). One end of the upper rotating shaft (312) extends out of the upper support (31) and is fixedly connected to the middle of the upper crank (314). The upper end of the upper crank (314) is hinged to the lower end of the transmission connecting rod (27), and the lower end of the upper crank (314) is connected to the upper end of the lower crank (324). A lower rotating shaft (322) is rotatably mounted on the lower support (32). A lower feed wheel (321) is sleeved on the lower rotating shaft (322). The lower rotating shaft (322) and the lower feed wheel (321) are connected by a lower one-way needle roller bearing (323). The lower end of the lower crank (324) is fixedly connected to the fixing sleeve (36) of the lower rotating shaft (322) or the lower one-way needle roller bearing (323). An elongated hole (325) is provided on the lower crank (324). The length direction of the elongated hole (325) is parallel to the length direction of the lower crank (324). A connector (326) is installed at the lower end of the upper crank (314). The connector (326) can slide back and forth along the elongated hole (325). The upper feed wheel (311) and the lower feed wheel (321) have opposite rotational directions.

7. A thread feeding system for a sewing machine according to claim 6, characterized in that: The upper support (31) is fixedly connected to a pressure foot (33) on its front side. An adjusting rod (34) is fixedly connected to the upper end of the upper support (31). The adjusting rod (34) passes through the machine head and extends out from the upper end of the machine head. An adjusting nut (35) is threaded to the upper end of the adjusting rod (34). Rotating the adjusting nut (35) can adjust the height of the upper support (31).

8. A thread feeding system for a sewing machine according to claim 6, characterized in that: Both the upper one-way needle roller bearing (313) and the lower one-way needle roller bearing (323) include a fixed sleeve (36) and an outer ring (37). The fixed sleeve (36) is fixedly connected to the corresponding upper rotating shaft (312) or lower rotating shaft (322). The fixed sleeve (36) and the outer ring (37) are rotatably connected in one direction. The outer ring (37) is tightly fitted to the corresponding upper feed wheel (311) and lower feed wheel (321).

9. A feeding system for a sewing machine according to claim 6, characterized in that: Small protrusions (38) are evenly distributed on the outer peripheral surfaces of the upper feed wheel (311) and the lower feed wheel (321).

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