Computer sewing machine

Abstract

The utility model provides a computer sewing machine, and belongs to the technical field of sewing machines. The problem that an existing sewing machine is not high in sewing quality is solved. The computer sewing machine comprises a base, a needle plate with a needle falling hole and a rotating shuttle located below the needle plate, and further comprises a guide seat arranged in the base, a transmission shaft located below the rotating shuttle and a thread shifting rod which is in a C-shaped strip shape and is arranged around the periphery of the rotating shuttle. The transmission shaft is horizontally arranged in the front-back direction of the sewing machine and connected to the guide seat in a sliding mode, the lower end of the thread shifting rod is connected with the transmission shaft, and the transmission shaft can do reciprocating motion in the axial direction and do circumferential reciprocating rotation at the same time, so that the upper end of the thread shifting rod does circumferential circulating motion and can be located between the needle falling hole and the rotating shuttle. According to the design of the computer sewing machine, the control difficulty is reduced, the sewing error is obviously reduced, and the sewing quality is further improved.

Description

A computerized sewing machine Technical Field

[0001] This utility model belongs to the field of sewing machine technology and relates to a computerized sewing machine. Background Technology

[0002] Sewing machines, as indispensable equipment in the garment manufacturing and other sewing industries, have a history of hundreds of years. With the continuous development of industrial technology and the intensification of market competition, the garment industry and other industries have placed higher demands on the automation, intelligence, and efficiency of sewing equipment. Against this backdrop, computerized sewing machines, such as pattern sewing machines and design sewing machines, have emerged.

[0003] Computerized sewing machines are products that combine traditional sewing techniques with modern numerical control and automation technologies. They mainly consist of a base with a worktable, a sewing head, a rotary hook, and a feeding device for holding the fabric. In traditional computerized sewing machines, the sewing head and rotary hook system are fixed in orientation; they do not rotate with changes in the fabric feeding direction. When this type of computerized sewing machine is used to sew patterns, the fabric moves horizontally in different directions with the feeding device. This results in some stitches being forward stitches (stitch 301) as shown in Figure 7, and others being reverse stitches (stitch 319) as shown in Figure 8. Since forward stitches generally ensure aesthetics and consistency, only forward stitches can be used when sewing high-end garments, leather goods, and other products requiring high sewing quality. Therefore, to ensure product aesthetics, it is necessary to avoid reverse stitches, a requirement that this type of computerized sewing machine clearly cannot meet.

[0004] To address the aforementioned technical issues, current methods employ a structure where the sewing head and rotary hook system rotate in the direction of sewing to prevent reverse stitches. For example, a template sewing machine with a freely rotatable and height-adjustable sewing head (authorization announcement number: CN207582086U) disclosed in Chinese patent literature uses a rotary motor located inside the sewing head assembly to achieve synchronous rotation of the upper sewing head and bobbin thread mechanism via a synchronous belt. A lifting mechanism is also provided between the upper sewing head and the sewing head assembly to drive the upper sewing head to rise and fall. This device allows the upper sewing head and bobbin thread mechanism to rotate in the direction of the feed, ensuring that the needle bar and rotary hook automatically adjust their direction according to the sewing pattern, thus effectively preventing reverse stitches. However, this type of computerized sewing machine still has the following shortcomings:

[0005] 1. In computerized sewing machines, the sewing head and rotary hook system rotate in the fabric feeding direction, resulting in a complex mechanism and high precision requirements. This complex mechanical structure is prone to cumulative errors, leading to deviations in the rotation angle or synchronization of the sewing head and rotary hook system. This affects sewing accuracy, causing uneven stitches or skipped stitches. Therefore, existing computerized sewing machines still suffer from insufficient sewing quality and aesthetics.

[0006] 2. The sewing machine head and rotary hook system rotate in the sewing direction, which requires the addition of corresponding drive and transmission structures. Moreover, the mechanical structure of the sewing machine head and rotary hook system will be more complex, which leads to an increase in the number of sewing machine parts and a higher manufacturing cost. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a computerized sewing machine. This invention can prevent reverse stitches during the sewing process and solve the problem of low sewing quality in existing sewing machines.

[0008] The purpose of this utility model can be achieved through the following technical solution: A computerized sewing machine includes a base, a needle plate with a needle hole, and a rotary hook located below the needle plate. The computerized sewing machine further includes a guide seat located within the base, a drive shaft located below the rotary hook, and a C-shaped thread guide rod arranged around the outer periphery of the rotary hook. The drive shaft is horizontally arranged along the front-rear direction of the sewing machine and slidably connected to the guide seat. The lower end of the thread guide rod is connected to the drive shaft. The drive shaft can reciprocate axially and rotate circumferentially, causing the upper end of the thread guide rod to perform circumferential cyclic movement and be positioned between the needle hole and the rotary hook.

[0009] In this sewing machine, the drive shaft is located below the rotary hook, allowing it to move freely and avoid the hook, thus facilitating the operation of the thread guide lever. The thread guide lever is C-shaped, effectively utilizing the space on the side of the rotary hook for its installation. This allows the upper end of the thread guide lever to extend into the narrow space between the rotary hook and the needle plate to guide the thread. In this way, despite the limited internal space of the base, the drive shaft and thread guide lever are installed, and the thread guiding action is performed through the thread guide lever to prevent reverse stitches.

[0010] Specifically, the principle by which this computerized sewing machine avoids reverse stitches is as follows:

[0011] When a computerized sewing machine sews patterns, the fabric moves horizontally in different directions with the feed device. When the machine is sewing forward, forward stitches are formed on the fabric. However, when the machine is sewing backward, if the position of the bobbin thread between the rotary hook and the needle plate is not changed by the thread lever, and the needle goes down normally, backward stitches will be formed. This is because after the rotary hook expands the top thread loop and places it on the bobbin thread, the needle needs to move upward. During this process, the top thread on the needle passes between the bobbin thread and the top thread on the fabric and tightens upward, eventually intertwining the top and bottom threads to form a "knot," thus creating a backward stitch.

[0012] In this computerized sewing machine, the drive shaft can reciprocate axially and rotate circumferentially, driving the thread guide lever to reciprocate in the front-to-back direction and swing left and right. This causes the upper end of the thread guide lever to perform a circumferential elliptical motion. When the sewing machine is sewing in reverse, before the needle enters the machine, the upper end of the thread guide lever passes between the needle hole and the rotary hook, pushing the bobbin thread between the rotary hook and the needle plate. This causes a portion of the bobbin thread to cross the axis of the needle before the needle enters the machine. When the needle moves downwards, bringing the top thread below the needle plate, the oscillation of the thread guide lever moves it away from the rotary hook, causing it to disengage from the bobbin thread. At this point, because the bobbin thread cannot return to its initial position due to the obstruction of the needle, the top thread, along with the bobbin thread on the fabric, is on the same side of the top thread on the needle as the needle moves upwards to tighten. This prevents the top thread on the needle from passing between the bobbin thread and the top thread on the fabric for tightening, thus avoiding knots between the bobbin and the top thread, ultimately resulting in a neat, straight stitch.

[0013] Therefore, this sewing machine effectively avoids reverse stitches during sewing by adding a thread guide lever with a "stitch conversion" function. Furthermore, this design only requires coordination with the needle's downward movement to control the thread guide lever's action; the machine head and rotary hook do not need to rotate with the sewing direction, thus eliminating the problem of reduced sewing quality caused by deviations in the rotation angle or synchronization of the machine head and rotary hook. Therefore, this sewing machine design not only reduces control difficulty but also significantly reduces sewing errors, further improving sewing quality. Simultaneously, the drive shaft is axially slidably connected to the guide seat, which supports and guides the drive shaft, ensuring stable drive shaft movement. This, in turn, reliably drives the thread guide lever to guide the thread, improving thread guiding accuracy and effect, thereby more reliably preventing reverse stitches during sewing.

[0014] In the aforementioned computerized sewing machine, this machine also includes a strip-shaped crank located at the rear end of the drive shaft. The crank is inclined and perpendicular to the drive shaft, and the lower end of the thread guide lever is fixedly connected to the drive shaft via the crank. The crank facilitates the installation of the thread guide lever, and the inclined crank position ensures that the upper end of the crank avoids the rotary hook. During the forward and backward movement of the crank and its reciprocating swing with the drive shaft, the upper end of the crank will not interfere with the rotary hook. This allows the crank to be made longer, thereby shortening the length of the thread guide lever. This helps prevent the thinner thread guide lever from deforming, improving thread guiding accuracy and effect, and thus more reliably preventing the generation of reverse stitches during sewing.

[0015] In the aforementioned computerized sewing machine, the lower end of the thread-picking lever is fixedly connected to the rear end of the drive shaft. Specifically, it can be welded or integrally molded. This structure, where the lower end of the thread-picking lever is directly connected to the drive shaft, reduces the number of parts and lowers manufacturing costs.

[0016] In the aforementioned computerized sewing machine, this computerized sewing machine also includes a U-shaped shaft fork, a vertically arranged thread guide wheel located on the side of the shaft fork, and a motor for driving the thread guide wheel to rotate. The closed end of the shaft fork is arranged rearward and is fixedly connected to the front end of the transmission shaft. The shaft fork has an inner shaft inside, which is perpendicular to the transmission shaft and its two ends slide through the two opposite side walls of the shaft fork. The thread guide wheel has a protrusion that is inclined relative to its rotation center line. The protrusion is fixedly connected to the inner shaft, and one end of the protrusion is fixedly connected to the eccentric position of the thread guide wheel.

[0017] In this structure, because the convex post is eccentric to the wire-picking wheel and inclined relative to the rotation center line of the wire-picking wheel, the convex post will undergo torsional motion when the wire-picking wheel rotates, and the convex post will have a forward and backward displacement, thereby driving the shaft fork and the drive shaft to move back and forth. Since the two ends of the inner shaft slide through the two opposite side walls of the shaft fork, during the torsional motion of the convex post, it can also drive the inner shaft to swing left and right and move axially on the shaft fork. The left and right swing of the inner shaft can drive the shaft fork and the drive shaft to reciprocate, ultimately causing the upper end of the wire-picking lever to perform circumferential circular motion to pick up the wire.

[0018] In conventional techniques, to achieve simultaneous axial reciprocating movement and circumferential oscillation of a shaft, two motors are typically used. One motor drives the shaft axially, while the other drives it circumferentially. Such a structure requires relatively complex control algorithms to coordinate the two motors. This design differs from conventional techniques. It employs a power transmission structure formed by an eccentric and inclined convex column, inner shaft, and shaft fork. This ingeniously converts the unidirectional rotational motion of motor one into the torsional motion of the convex column and overall movement. Thus, with a single motor, the transmission shaft can achieve both axial reciprocating movement and circumferential oscillation. This design offers advantages such as simple control and stable operation, ensuring precise thread-picking by the thread-picking lever and preventing thread-picking failure due to operational errors, thereby guaranteeing sewing quality.

[0019] In the aforementioned computerized sewing machine, the inner shaft has a cylindrical shape in the middle and a connecting hole perpendicular to the axial direction of the inner shaft, with the protruding post fixedly inserted into the connecting hole. This structure facilitates the fixed connection between the protruding post and the inner shaft, and ensures the stability of the connection.

[0020] In the aforementioned computerized sewing machine, the thread guide lever is formed by bending a metal strip. This design, with its simple metal strip shape, is not only easy to manufacture, but also allows for a smaller diameter, making it easier to insert into the narrow space between the needle plate and the rotary hook to perform the thread-pulling action.

[0021] In the aforementioned computerized sewing machine, this machine also includes a strip-shaped rocker arm. The middle part of the rocker arm is fixedly connected to the rear end of the drive shaft, and the lower end of the thread guide lever is connected to the drive shaft via the rocker arm. The rocker arm facilitates the installation of the thread guide lever, and the connection of the lower end of the thread guide lever to the drive shaft via the rocker arm shortens the length of the thread guide lever. This helps prevent deformation of thinner thread guide levers, improves thread guiding accuracy and effect, and thus more reliably avoids the generation of reverse stitches during sewing.

[0022] In the aforementioned computerized sewing machine, this machine also includes a connecting rod and a horizontally arranged, independently rotatable eccentric wheel. The guide seat has a groove extending in the front-to-back direction. A guide shaft is slidably mounted within the groove. The front end of the transmission shaft is axially fixed and circumferentially rotatably connected to the guide shaft. Both ends of the connecting rod are respectively hinged to the guide shaft and the eccentric position of the eccentric wheel. In actual manufacturing, a second motor is fixedly mounted inside the base. The second motor drives the eccentric wheel to rotate, which in turn drives the guide shaft to slide back and forth within the groove via the connecting rod, thereby causing the transmission shaft to move back and forth, i.e., axially reciprocating. The groove on the guide seat, with the transmission shaft slidably connected within it via the guide shaft, ensures the stability of the transmission shaft's movement, thereby improving thread-picking accuracy and effect.

[0023] In the aforementioned computerized sewing machine, this machine also includes a vertically arranged, independently rotating cam. The rotation center line of the cam is parallel to the transmission shaft, and the transmission shaft is equipped with an elastic reset element. Under the action of the elastic reset element, when the rocker arm moves back and forth with the transmission shaft, the lower end of the rocker arm always slides against the outer circumferential surface of the cam. In actual manufacturing, a third motor is also fixedly installed inside the base, which drives the cam to rotate. Both the second and third motors are servo motors and are controlled by the sewing machine control system, thus coordinating the timing and angle of their rotation. When the cam rotates, the tip of the cam intermittently pushes the rocker arm, causing the rocker arm and thread-picking lever to swing left and right, while the transmission shaft reciprocates. The rotation of the transmission shaft causes the elastic reset element to deform, ensuring that the lower end of the rocker arm always slides against the outer circumferential surface of the cam. Through this design, the transmission shaft ultimately reciprocates axially while simultaneously rotating circumferentially.

[0024] In the aforementioned computerized sewing machine, the elastic reset element is a torsion spring sleeved on the drive shaft. One end of the torsion spring is fixed to the drive shaft, and the other end is fixed to the guide shaft. The torsion spring has the advantages of easy installation and space saving. When the drive shaft rotates, it causes the torsion spring to deform, thereby relying on the action of the torsion spring to ensure that the lower end of the rocker arm can always slide against the outer peripheral surface of the cam.

[0025] Compared with existing technologies, this computerized sewing machine has the following advantages:

[0026] 1. In this sewing machine, by adding a thread guide lever, which has the function of "stitch conversion", it can avoid the occurrence of reverse stitches during the sewing process, ensuring the aesthetics and consistency of the sewing, so that the computer sewing machine can be well applied to sewing some high-end clothing, leather products and other occasions with high sewing quality requirements.

[0027] 2. This sewing machine only requires the needle to move down, controlling the thread guide lever to reciprocate above the rotary hook. The sewing head and rotary hook do not need to rotate with the sewing direction, thus eliminating the problem of reduced sewing quality caused by deviations in the rotation angle or synchronization of the sewing head and rotary hook. Therefore, the design of this computerized sewing machine not only reduces control difficulty but also significantly reduces sewing errors, further improving sewing quality.

[0028] 3. In this computerized sewing machine, the thread guide lever is located on the side of the rotary hook, while the drive shaft is located below the rotary hook. The transmission assembly, consisting of components such as the shaft fork and thread guide wheel, is located in front of the drive shaft. Therefore, this computerized sewing machine makes reasonable use of the space below the rotary hook for the arrangement of the transmission assembly, resulting in a more rational space design. Moreover, during maintenance, the transmission assembly and thread guide lever are exposed inside the base, preventing problems such as difficulty in disassembling and assembling parts due to obstruction by the base. Thus, this computerized sewing machine also has the advantage of convenient maintenance and adjustment. Attached Figure Description

[0029] Figure 1 is a partial structural diagram of Embodiment 1 of this computerized sewing machine.

[0030] Figure 2 is a schematic diagram of the connection structure between the dial wheel and the dial rod in Embodiment 1.

[0031] Figure 3 is a schematic diagram of the working state of the drive source driving the dial lever in Embodiment 1.

[0032] Figure 4 is a schematic diagram of the working state of the drive source driving the dial lever in Embodiment 1.

[0033] Figure 5 is a partial structural schematic diagram of Embodiment 2.

[0034] Figure 6 is a partial structural schematic diagram of Embodiment 3.

[0035] Figure 7 is a schematic diagram of the positive line pattern.

[0036] Figure 8 is a schematic diagram of the reverse stitch.

[0037] Figure 9 is a schematic diagram of the upward tightening of the surface line to form a reverse line.

[0038] Figure 10 is a schematic diagram of the upward tightening of the surface line to form a positive line.

[0039] In the diagram: 1. Base; 2. Needle plate; 21. Needle drop hole; 3. Hook; 4. Thread take-up lever; 5. Crank; 6. Drive shaft; 7. Shaft fork; 8. Thread take-up wheel; 9. Guide seat; 91. Slide groove; 10. Inner shaft; 101. Connecting hole; 11. Protruding post; 12. Rocker arm; 13. Motor 1; 14. Connecting rod; 15. Eccentric wheel; 16. Cam; 17. Motor 2; 18. Guide shaft; 19. Elastic reset element; 20. Needle; 21. Motor 3. Detailed Implementation

[0040] 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.

[0041] Example 1

[0042] As shown in Figure 1, this computerized sewing machine includes a base 1, a needle plate 2 with a needle drop hole 21, a rotary hook 3 located below the needle plate 2, a guide seat 9 located within the base 1, and a C-shaped thread guide 4 arranged around the outer periphery of the rotary hook 3. The rotation center line of the rotary hook 3 is horizontally arranged along the front-back direction of the sewing machine. The thread guide 4 is formed by bending a metal strip and is arranged vertically. Below the rotary hook 3 is a drive shaft 6 arranged horizontally along the front-back direction. The drive shaft 6 is slidably connected to the guide seat 9 along the axial direction. Specifically, the guide seat 9 has a guide hole, and the rotating shaft slides through the guide hole. The lower end of the thread guide 4 is connected to the drive shaft 6. The drive shaft 6 can move back and forth along the axial direction and rotate back and forth in the circumferential direction, so that the upper end of the thread guide 4 can perform circumferential cyclic motion and be positioned between the needle drop hole 21 and the rotary hook 3.

[0043] Furthermore, as shown in Figures 1 and 2, this computerized sewing machine also includes a U-shaped shaft fork 7, a vertically arranged thread guide wheel 8 located on the side of the shaft fork 7, a motor 13 for driving the thread guide wheel 8 to rotate, and a strip-shaped crank 5 located at the rear end of the transmission shaft 6. The crank 5 is inclined and perpendicular to the transmission shaft 6. The lower end of the thread guide rod 4 is fixedly connected to the upper end of the crank 5, and the lower end of the crank 5 is fixedly connected to the rear end of the transmission shaft 6. The closed end of the shaft fork 7 is arranged facing rearward and is fixedly connected to the front end of the drive shaft 6. The shaft fork 7 is provided with an inner shaft 10. The middle part of the inner shaft 10 is cylindrical and has a connecting hole 101 perpendicular to the axial direction of the inner shaft 10. The inner shaft 10 is perpendicular to the drive shaft 6 and the two ends of the inner shaft 10 slide through the two opposite side walls of the shaft fork 7. The wire guide wheel 8 has a protrusion 11 that is inclined relative to its rotation center line. The protrusion 11 is fixedly inserted into the connecting hole 101, and one end of the protrusion 11 is fixedly connected to the eccentric position of the wire guide wheel 8.

[0044] As shown in Figures 3 and 4, since the protruding post 11 is eccentric to the wire-picking wheel 8 and also inclined to the rotation center line of the wire-picking wheel 8, the protruding post 11 will undergo torsional motion when the wire-picking wheel 8 rotates. At the same time, the protruding post 11 has a forward and backward displacement, which in turn drives the shaft fork 7 and the drive shaft 6 to move back and forth. Since the two ends of the inner shaft 10 slide through the two opposite side walls of the shaft fork 7, during the torsional motion of the protruding post 11, it can also drive the inner shaft 10 to swing left and right and move axially on the shaft fork 7. The left and right swing of the inner shaft 10 can drive the shaft fork 7 and the drive shaft 6 to reciprocate, ultimately causing the upper end of the wire-picking lever 4 to perform circumferential circular motion to pick up the wire.

[0045] The principle by which this computerized sewing machine avoids reverse stitches is as follows:

[0046] When a computerized sewing machine sews patterns, the fabric moves horizontally in different directions with the feed device. When the machine is sewing forward, forward stitches are formed on the fabric. However, when the machine is sewing backward, if the position of the bobbin thread between the rotary hook 3 and the needle plate 2 is not changed by the thread lever 4, and the needle 20 goes down normally, backward stitches will be formed. This is because, as shown in Figure 9, after the rotary hook 3 expands the top thread loop and places it on the bobbin thread, the needle 20 needs to move upward. During this process, the top thread on the needle 20 passes between the bobbin thread and the top thread on the fabric and tightens upward. Finally, the top thread and bobbin thread intertwine to form a "knot," resulting in the backward stitches shown in Figure 8.

[0047] In this computerized sewing machine, the drive shaft 6 can reciprocate axially and rotate circumferentially, thereby driving the thread guide lever 4 to reciprocate in the front-to-back direction and swing left and right. This causes the upper end of the thread guide lever 4 to perform a circumferential elliptical motion. When the sewing machine is sewing in reverse, before the needle 20 inserts, the upper end of the thread guide lever 4 passes between the needle drop hole 21 and the rotary hook 3, pushing the bobbin thread between the rotary hook 3 and the needle plate 2, causing a portion of the bobbin thread to cross the axis of the needle 20. Then, the needle 20 inserts. After the needle 20 moves downward and brings the top thread below the needle plate 2, the swinging of the thread guide lever 4 moves it away from the rotary hook 3, causing the thread guide lever 4 to detach from the bobbin thread. At this point, as shown in Figure 10, because the bottom thread cannot be reset to its initial position due to the obstruction of the needle 20, the top thread is located on the same side of the top thread on the needle 20 during the tightening process as the needle 20 moves upward. This prevents the top thread on the needle 20 from passing between the bottom thread and the top thread on the fabric for tightening, thus avoiding the situation where the top thread and bottom thread "tangle". Finally, a beautiful positive stitch is formed as shown in Figure 7.

[0048] Example 2

[0049] This embodiment is basically the same in structure and principle as Embodiment 1, except that, as shown in Figure 5, this computerized sewing machine also includes a connecting rod 14, a strip-shaped rocker arm 12, a horizontally arranged eccentric wheel 15 that can rotate independently, and a vertically arranged cam 16 that can rotate independently. A second motor 17 and a third motor 21 are also fixedly installed inside the base 1. The second motor 17 drives the eccentric wheel 15 to rotate, and the third motor 21 drives the cam 16 to rotate. Specifically, the middle part of the rocker arm 12 is fixedly connected to the rear end of the transmission shaft 6, and the lower end of the thread-picking lever 4 is fixedly connected to the upper end of the rocker arm 12.

[0050] The guide seat 9 has a groove 91 arranged in the front-to-back direction. A guide shaft 18 is slidably arranged in the groove 91. The front end of the transmission shaft 6 is axially fixed and circumferentially rotatably connected to the guide shaft 18. The two ends of the connecting rod 14 are respectively hinged to the guide shaft 18 and the eccentric position of the eccentric wheel 15. The rotation center line of the cam 16 is parallel to the transmission shaft 6. The transmission shaft 6 is provided with an elastic reset member 19. Under the action of the elastic reset member 19, when the rocker arm 12 moves back and forth with the transmission shaft 6, the lower end of the rocker arm 12 always slides against the outer peripheral surface of the cam 16. Specifically, the elastic reset member 19 is a torsion spring sleeved on the transmission shaft 6. One end of the torsion spring is fixed to the transmission shaft 6, and the other end is fixed to the guide shaft 18.

[0051] Both motor 17 and motor 21 are servo motors and are controlled by the sewing machine control system, thus coordinating the timing and angle of their rotation. When the eccentric wheel 15 rotates, it drives the guide shaft 18 to slide back and forth in the groove 91 via the connecting rod 14, thereby driving the transmission shaft 6 to move back and forth, i.e., axial reciprocating movement. At the same time, the cam 16 rotates, and the tip of the cam 16 intermittently pushes the rocker arm 12, causing the rocker arm 12 and the thread-picking lever 4 to swing left and right, making the transmission shaft 6 reciprocate. When the transmission shaft 6 rotates, it can deform the elastic reset member 19, so that the lower end of the rocker arm 12 can always slide against the outer peripheral surface of the cam 16 by the action of the elastic reset member 19. Through the above design, the transmission shaft 6 is made to move back and forth along the axial direction and rotate back and forth in the circumferential direction, thereby driving the thread-picking rod 4 to move back and forth in the front and back direction and swing left and right, so that the upper end of the thread-picking rod 4 can perform circumferential circular motion and be positioned between the needle hole 21 and the rotary hook 3, thereby realizing the thread-picking function.

[0052] Example 3

[0053] This embodiment is basically the same in structure and principle as Embodiment 1, except that, as shown in Figure 6, the lower end of the wire-picking lever 4 is welded or integrally formed to the rear end of the drive shaft 6. The motor 13, relying on the shaft fork 7, wire-picking wheel 8, inner shaft 10, and protruding post 11 as in Embodiment 1, drives the drive shaft 6 to move back and forth and rotate simultaneously. In this structure, the lower end of the wire-picking lever 4 is directly connected to the drive shaft 6, which reduces the number of parts and lowers manufacturing costs.

[0054] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

[0055] Although this document frequently uses terms such as 1. base; 2. needle plate; 21. needle drop hole; 3. rotary hook; 4. thread guide lever; 5. crank; 6. drive shaft; 7. shaft fork; 8. thread guide wheel; 9. guide seat; 91. slide groove; 10. inner shaft; 101. connecting hole; 11. protruding post; 12. rocker arm; 13. motor one; 14. connecting rod; 15. eccentric wheel; 16. cam; 17. motor two; 18. guide shaft; 19. elastic reset element; 20. needle; 21. motor three, etc., the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any kind of additional limitation would contradict the spirit of this utility model.

Claims

1. A computerized sewing machine, comprising a base (1), a needle plate (2) having a needle drop hole (21), and a rotary hook (3) located below the needle plate (2), characterized in that, This computerized sewing machine also includes a guide seat (9) located in the base (1), a drive shaft (6) located below the rotary hook (3), and a C-shaped bar (4) arranged around the outer periphery of the rotary hook (3). The drive shaft (6) is horizontally arranged along the front-back direction of the sewing machine and slidably connected to the guide seat (9). The lower end of the bar (4) is connected to the drive shaft (6). The drive shaft (6) can move back and forth along the axial direction and rotate back and forth in the circumferential direction, so that the upper end of the bar (4) can perform circumferential circular motion and be positioned between the needle drop hole (21) and the rotary hook (3).

2. The computerized sewing machine according to claim 1, characterized in that, The computerized sewing machine also includes a strip-shaped crank (5) located at the rear end of the drive shaft (6). The crank (5) is inclined and perpendicular to the drive shaft (6). The lower end of the thread-pulling rod (4) is fixedly connected to the drive shaft (6) through the crank (5).

3. The computerized sewing machine according to claim 1, characterized in that, The dial lever (4) is fixedly connected to the rear end of the drive shaft (6).

4. The computerized sewing machine according to claim 1, 2, or 3, characterized in that, This computerized sewing machine also includes a U-shaped shaft fork (7), a vertically arranged thread guide wheel (8) located on the side of the shaft fork (7), and a motor (13) for driving the thread guide wheel (8) to rotate. The closed end of the shaft fork (7) is arranged facing rearward and is fixedly connected to the front end of the transmission shaft (6). The shaft fork (7) is provided with an inner shaft (10). The inner shaft (10) is perpendicular to the transmission shaft (6), and the two ends of the inner shaft (10) slide through the two opposite side walls of the shaft fork (7). The thread guide wheel (8) has a protrusion (11) that is inclined relative to its rotation center line. The protrusion (11) is fixedly connected to the inner shaft (10), and one end of the protrusion (11) is fixedly connected to the eccentric position of the thread guide wheel (8).

5. The computerized sewing machine according to claim 4, characterized in that, The middle part of the inner shaft (10) is cylindrical and has a connecting hole (101) perpendicular to the axial direction of the inner shaft (10). The protruding post (11) is fixedly inserted into the connecting hole (101).

6. The computerized sewing machine according to claim 1, 2, or 3, characterized in that, The dial lever (4) is formed by bending a metal strip.

7. The computerized sewing machine according to claim 1, characterized in that, The computerized sewing machine also includes a bar-shaped rocker arm (12), the middle part of which is fixedly connected to the rear end of the drive shaft (6), and the lower end of the thread-pulling rod (4) is connected to the drive shaft (6) through the rocker arm (12).

8. The computerized sewing machine according to claim 7, characterized in that, This computerized sewing machine also includes a connecting rod (14) and a horizontally arranged eccentric wheel (15) that can rotate independently. The guide seat (9) has a sliding groove (91) arranged in the front-back direction. A guide shaft (18) is slidably arranged in the sliding groove (91). The front end of the transmission shaft (6) is axially fixed and circumferentially rotatably connected to the guide shaft (18). The two ends of the connecting rod (14) are respectively hinged to the guide shaft (18) and the eccentric position of the eccentric wheel (15).

9. The computerized sewing machine according to claim 8, characterized in that, This computer sewing machine also includes a vertically arranged cam (16) that can rotate independently. The rotation center line of the cam (16) is parallel to the transmission shaft (6). The transmission shaft (6) is provided with an elastic reset member (19). Under the action of the elastic reset member (19), when the rocker arm (12) moves back and forth with the transmission shaft (6), the lower end of the rocker arm (12) always slides against the outer peripheral surface of the cam (16).

10. The computerized sewing machine according to claim 9, characterized in that, The elastic reset component (19) is a torsion spring sleeved on the transmission shaft (6), with one end of the torsion spring fixed on the transmission shaft (6) and the other end fixed on the guide shaft (18).

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