Upper thread supply mechanism of sewing machine

Abstract

The utility model discloses an upper thread supply mechanism of a sewing machine, and relates to the technical field of sewing machines. The sewing machine is provided with a machine arm, a main shaft motor is arranged on the machine arm, the main shaft motor is in locking connection with a main shaft to drive the main shaft to rotate, and the upper thread supply mechanism of the sewing machine comprises a driving motor, a thread take-up lever, a thread passing hook and other components. The upper thread feeding mechanism of the sewing machine is additionally and independently provided with the driving motor as an independent driving source, so that the situation that the control relation between the upper thread feeding mechanism and the movement of the main shaft is complicated due to the fact that the movement of the take-up lever is controlled by the rotation of the main shaft motor is avoided. The upper thread feeding mechanism solves the problem that in the prior art, the thread taking-up amount of the upper thread feeding mechanism is difficult to adjust rapidly according to the type of fabric.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, and more specifically, to a thread supply mechanism for a sewing machine. Background Art

[0002] In the current field of industrial sewing machinery, the driving mode of the thread supply mechanism is mostly that the main shaft motor is connected to the thread take-up mechanism through another mechanism to form a sewing stitch. However, due to its relatively complex mechanical structure and the need to share resources with the main shaft power system of the sewing machine, this design has certain limitations in terms of degrees of freedom of movement. Moreover, the higher the complexity of the mechanism, the lower the reliability and the greater the maintenance difficulty. This has led to difficulties in adjusting the supply quantity and timing of the thread according to the specific requirements of the sewing task in actual applications. To adapt to different types of sewing needs, manufacturers usually equip different models of sewing machines with dedicated thread take-up mechanisms to ensure the sewing effect. During the actual operation process, due to the variety of fabrics, including but not limited to knitted fabrics, woven fabrics, lightweight fabrics, and heavyweight fabrics, etc., each of which has unique technological characteristics and thickness differences, this poses high requirements for the supply quantity and supply timing of the thread take-up mechanism to supply the thread for different fabrics. The existing technical solutions have limitations in quickly adjusting the supply quantity and timing of the thread, and usually require operators with professional skills and rich experience to operate, and it is often difficult to achieve the most ideal effect.

[0003] The utility model with the publication number CN216838498U discloses a thread take-up mechanism for a sewing machine, and its design still follows the traditional method, that is, using the main shaft of the sewing machine to drive the thread take-up lever to realize the adjustment of the thread quantity. However, this method has deficiencies in quickly adjusting the supply quantity and supply timing of the thread. This design limits the adaptability to different types of fabrics, especially when rapid adjustment is required for specific sewing conditions. Therefore, although this utility model provides a solution, it still faces difficulties in terms of flexibility and efficiency in actual operation. Summary of the Utility Model

[0004] Aiming at the limitations of the existing sewing machines in adjusting the thread supply mechanism, the utility model proposes a new thread supply mechanism for a sewing machine. This new mechanism design allows users to quickly change the supply quantity of the thread and the feeding time point for fabrics with different characteristics. This design significantly improves the efficiency of sewing work and improves the sewing stitch. Through this mechanism, even when facing diverse sewing needs, such as dealing with fabrics of different thicknesses or processes, more precise and flexible thread control can be achieved, thus ensuring the smoothness of the sewing process and high standards of finished products.

[0005] The technical solution of the utility model is: a sewing machine upper thread supply mechanism, the sewing machine has a machine arm, a spindle motor is arranged on the machine arm, the spindle motor is locked and connected with the spindle to drive the spindle to rotate, and the sewing machine upper thread supply mechanism includes a driving motor, a thread take-up rod, a thread hook and other components. The sewing machine upper thread supply mechanism is separately provided with the driving motor as an independent driving source, so as to avoid the movement of the thread take-up rod being controlled by the rotation of the spindle motor, thereby complicating the control relationship between the upper thread feeding mechanism and the spindle movement. The utility model enables the sewing machine to quickly adjust the movement of the thread take-up rod when facing different fabrics through an independently controlled driving motor, greatly improves the efficiency of sewing operations, and significantly improves the quality of sewing stitches. In addition, the thread take-up rod design of the utility model is different from the limitation of the traditional single threading hole, and adopts multiple threading holes. The thread take-up rod can complete more thread taking in a shorter swing stroke, and at the same time disperses the tension of the upper thread, so that the upper thread is not easy to break, and also reduces the wear of the upper thread on the thread take-up rod. Through the above innovation, the utility model solves the problem in the prior art that it is difficult to quickly adjust the thread take-up amount of the upper thread feeding mechanism according to the type of fabric.

[0006] Preferably, the motor is installed on the machine arm, and transmission is achieved between the output end of the driving motor and the thread take-up rod through an active crank and a connecting rod. One end of the active crank is locked and connected to the output end of the driving motor, one end of the connecting rod is hinged to the other end of the active crank, and the other end of the connecting rod is hinged to the connecting hole of the thread take-up rod.

[0007] Through the crank rocker mechanism, the drive motor rotates in one direction to a limit position within one input cycle, and the thread take-up rod can complete a reciprocating motion. When the drive motor rotates in the opposite direction to another limit position, the thread take-up rod completes a second reciprocating motion. That is, through the crank rocker, the thread take-up rod completes two swing cycles in one input cycle of the drive motor. Therefore, under the condition that the motor speed remains unchanged, the crank connecting rod mechanism is used to double the reciprocating motion frequency of the thread take-up rod, which can shorten the command operation response time and reduce the drive motor speed.

[0008] And because the crank rocker mechanism is used for transmission, it can be found that when the drive motor rotates a larger angle, the swing angle of the thread take-up rod is smaller. It is easier to control the swing of the thread take-up rod by using an independent drive source.

[0009] Preferably, a sleeve is provided at one end of the active crank, and a plurality of fixing holes are provided outside the sleeve, and the fixing holes penetrate the central hole of the drive sleeve. The active crank is connected to the drive motor in a transmission manner, and a flat surface is cut on the output end of the drive motor. After the output end of the drive motor is inserted into the drive sleeve, a fastener is installed in the fixing hole so that the fastener fits with the flat surface of the output end of the drive motor. When the output end of the drive motor rotates, the active crank can be driven to rotate synchronously, thereby realizing a transmission connection between the drive motor and the active crank.

[0010] In some embodiments, a thread passing hook is provided on the machine arm, and a plurality of thread passing holes are provided on the thread passing hook. The thread passing through the thread passing hole of the thread take-up lever is connected to the thread passing hook through the thread passing hole.

[0011] Preferably, reinforcing ribs are provided on the side surface of the driving crank. The driving crank is the driving member of the crank-rocker mechanism. Due to the characteristics of the rotation of the above-mentioned motor, the driving crank needs to frequently reverse during the rotation process and bears a large bending moment. And because the installation position of the driving crank is inside the machine arm of the sewing machine, the space is narrow, and it is necessary to avoid interference with other components, resulting in a small size of the driving crank. In order to increase the strength of the driving crank, reinforcing ribs are provided on both side surfaces of the driving crank.

[0012] Preferably, a groove is provided on the end surface of the driving crank. Since the end surface of the driving crank is not the main stress-bearing part, the material can be appropriately reduced without affecting the overall structural strength, thereby reducing the weight. At the same time, the inertia is also reduced, which is beneficial to the multiple reversals of the motor and improves the response speed of the thread supply mechanism.

[0013] Preferably, a rotating shaft hole is provided at the end of the thread take-up lever, a thread take-up lever shaft is provided on the machine arm, a rolling bearing is installed in the rotating shaft hole, and the thread take-up lever shaft is hinged to the rotating shaft hole. The cooperation between the thread take-up lever shaft and the rotating shaft hole enables the thread take-up lever to swing up and down relative to the machine arm. When the driving crank drives, the connecting rod moves accordingly, thereby pushing the thread take-up lever to swing around the thread take-up lever shaft to complete the step of supplying the thread.

[0014] In some embodiments, a thread guide is further provided on the machine arm, and the thread passes through the thread guide and then through the thread passing hole. The thread guide can further support and guide the thread, making the thread feeding path more accurate.

[0015] In some embodiments, the output end of the driving motor is directly locked and connected to the thread take-up lever. The driving motor directly drives the thread take-up lever to swing. As a result, the commutation frequency of the driving motor becomes higher, which greatly affects the running speed of the driving motor, puts high requirements on the response speed and acceleration time of the driving motor, and increases the procurement cost of the driving motor.

[0016] Preferably, the angular range of the reciprocating swing of the thread take-up lever is 20° to 35°.

[0017] The beneficial effects of the present utility model are:

[0018] By introducing an independent drive motor as the power source, the utility model significantly improves the supply efficiency of the upper thread and the stitch quality of the sewing machine. The independent drive design reduces the dependence on the main shaft and other mechanisms, allowing for quick adjustment of the upper thread feed amount and timing according to the fabric characteristics. In addition, the innovative design of the thread take-up lever, equipped with multiple thread passing holes, different from the traditional single-hole configuration, enables a larger thread take-up amount within a smaller swing range, simplifying the adjustment process. These improvements work together to optimize the sewing performance and meet the sewing needs of diverse fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. 1 is a schematic structural diagram of a sewing machine applying the utility model.

[0020] Figure 2 FIG. 2 is a schematic structural diagram inside the utility model.

[0021] Figure 3 FIG. 3 is a schematic structural diagram of another perspective inside the utility model.

[0022] Figure 4 FIG. 4 is a schematic connection diagram of the crank rocker of the utility model.

[0023] Figure 5 FIG. 5 is a schematic connection diagram of the crank rocker, the motor and the bracket cover of the utility model.

[0024] Figure 6 FIG. 6 is a schematic structural diagram of the thread passing hook of the utility model.

[0025] In the figures, 1 - machine base, 11 - main shaft motor, 12 - main shaft, 2 - machine arm, 21 - bracket cover, 211 - thread take-up lever shaft, 22 - thread take-up lever, 221 - thread take-up lever rotating shaft hole, 222 - connection hole, 223 - thread passing hole, 23 - thread passer, 231 - winding rod cap, 232 - winding rod, 24 - needle bar slide, 241 - needle bar slider, 242 - needle bar chute, 25 - needle bar connecting rod, 26 - needle bar cam, 27 - needle bar crank, 28 - driving crank, 281 - bushing, 282 - fixing hole, 283 - groove, 284 - reinforcing rib, 29 - connecting rod, 3 - drive motor, 31 - output end, 4 - upper thread, 5 - needle bar, 51 - needle bar guiding assembly, 52 - sewing needle, 6 - thread passing hook, 61 - winding hole. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The following further describes the utility model in conjunction with the drawings and specific embodiments, but the protection scope of the utility model is not limited thereto.

[0027] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", etc. is based on the direction or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. Terms such as "installation", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or there can be communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] Embodiment 1:

[0029] As Figures 1 to 5 shown, a sewing machine upper thread feeding mechanism, the main part of the sewing machine upper thread feeding mechanism consists of a machine base 1, a machine arm 2, and a driving motor 3. Among them, the machine base 1 is vertically connected to the machine arm 2, presenting a cantilever beam structure. When the upper thread feeding mechanism is working, the upper thread 4 is connected to a part of the structure on the machine arm 2, thereby realizing the feeding of the upper thread. The driving motor 3 is installed on the machine arm 2. In this embodiment, the driving motor 3 is installed on the bracket cover 21 at the other end face of the machine arm 2. The output end 31 of the driving motor 3 is connected to the bushing 281 of the active crank 28, and the locking between the output end 31 and the active crank 28 is achieved by installing fasteners in the fixing holes 282. There is a thread in the installation hole 282, and the output end 31 is machined, and there is a plane on the output end 31. Therefore, by screwing bolts into the two installation holes 282 so that the plane of the bolt fits with the plane of the output end 31, the locking between the output end 31 and the active crank 28 can be achieved. Thus, when the output end 31 of the driving motor 3 rotates, it drives the active crank 28 to rotate synchronously.

[0030] After the locking between the active crank 28 and the output end 31 is completed, the other end of the active crank 28 is hinged to the connecting rod 29. Rolling bearings are installed in both connecting holes of the connecting rod 29 to realize that the connections between the connecting rod 29 and the active crank 28 and the thread take-up lever 22 are both hinged and can rotate.

[0031] Since the crank-rocker mechanism connected to the thread take-up lever 22 is located inside the machine arm 2, and there are sewing machine components such as the main shaft 12 and the needle bar 5 in its vicinity, the overall movement range of the mechanism is small. Therefore, the designs of the driving crank 28, the connecting rod 29, and the thread take-up lever 22 all adopt miniaturized and lightweight designs. However, since the driving crank 28 is directly connected to the output end 31 of the driving motor 3, and because the movement trajectory of the thread take-up lever 22 is a reciprocating swing up and down, this requires the driving motor 3 to change its rotation direction relatively frequently. And the driving crank 28 directly connected to the output end 31 of the driving motor 3 needs to frequently bear torque and bending moment. If the structural design and material selection of the driving crank 28 are unreasonable, during long-term operation, it is very easy to produce bending deformation and even the risk of fracture. Seriously, it may interfere with the running main shaft 12, resulting in relatively serious damage to the entire sewing machine. In the case of limited space, adding reinforcing ribs 284 on both sides of the driving crank 28 can effectively improve the bending strength of the driving crank 28.

[0032] Since the end face of the driving crank 28 is not the main stress-bearing part during rotation, in order to meet the requirement that the thread take-up lever 22 can swing back and forth, it is required that the driving crank 28 can respond quickly. As is well known, the smaller the inertia of an object, the faster its response speed, and the inertia of an object is related to its mass. The smaller the mass, the smaller the inertia. Therefore, a groove 283 is machined on the end face of the driving crank 28. On the one hand, it will not affect the service strength of the driving crank 28. On the other hand, it can reduce the inertia of the driving crank 28, increase the response speed of the driving crank 28, shorten the response time of the driving crank 28, which is beneficial to better control the swing of the thread take-up lever 22. Improve the supply efficiency of the top thread and the quality of the stitch.

[0033] Both ends of the connecting rod 29 are provided with connecting holes. Since the connecting rod 29 does not transmit rotation, rolling bearings are installed in both connecting holes to be connected to the driving crank 28 and the thread take-up lever 22 respectively. The connecting piece is fixed to the bracket cover 21 by a pin shaft passing through the connecting hole. In order to prevent the end face of the driving crank 28 from contacting the bracket cover 21, resulting in too large frictional resistance, abnormal heating of the machine, and excessive damage to the driving crank 28 and the bracket cover 21, affecting the transmission of motion. Therefore, a spring washer needs to be installed between the driving crank 28 and the bracket cover 21 at the end face position where they will come into contact. The same is true for the connection between the driving crank 28 and the connecting rod 29 and the connection between the connecting rod 29 and the thread take-up lever 22.

[0034] The thread take-up lever 22 includes a thread take-up lever rotating shaft hole 221, a thread take-up lever connection hole 222, and a thread passing hole 223. The thread take-up lever rotating shaft hole 221 is located at one end of the thread take-up lever arm and is close to the thread take-up lever connection hole 222. The thread take-up lever 22 is fixed to the thread take-up lever shaft 211 of the bracket cover 21 through the thread take-up lever rotating shaft hole 221, and the thread take-up lever 22 can rotate relative to the bracket cover 21 through the thread take-up lever rotating shaft hole 221. The bracket cover 21 is provided with a rotating shaft for connecting with the thread take-up lever rotating shaft hole 221 of the thread take-up lever 22, and the bracket cover 21 is also provided with a corresponding groove that can accommodate the thread take-up lever rotating shaft hole 221. A rolling bearing is provided in the thread take-up lever rotating shaft hole 221 to reduce the rotational friction of the thread take-up lever 22. The thread take-up lever 22 can be divided into a thread take-up lever arm and a thread take-up lever front arm. Among them, the thread take-up lever rotating shaft hole 221 and the thread take-up lever connection hole 222 are provided on the thread take-up lever arm, and the thread passing hole 223 is provided on the thread take-up lever front arm. The thread take-up lever arm and the thread take-up lever front arm are in an L shape. The axis of the thread passing hole 223 is parallel to the thread take-up lever arm, while the axes of the thread take-up lever rotating shaft hole 221 and the thread take-up lever connection hole 222 are parallel to the thread take-up lever front arm.

[0035] A thread passer 23 is provided outside the machine arm 2, and a needle bar 5 and a needle bar slide 24 are also provided inside. The thread passer 23 is fixed to the outer shell of the machine arm 2, while the needle bar slide 24 is installed inside the machine arm 2. Needle bar chutes 242 are provided on both sides inside the needle bar slide 24, and needle bar sliders 241 are also installed in the needle bar chutes 242 and can slide thereon. The thread passer 23 is located below the thread take-up lever 22 and can further support and guide the thread 4. The thread passer 23 includes a thread winding rod 232 and a thread winding cap 231. There is a cooperation relationship between the thread passer 23 and the thread take-up lever 22. The cooperation between the thread passer 23 and the thread take-up lever 22 in a straight line controls the path of the thread. The thread 4 extending from the thread guiding components before passing through the thread passer 23 passes through and folds back multiple times between the thread take-up lever 22 and the thread passer 23, making the tightness of the thread 4 more appropriate.

[0036] The needle bar 5 is located inside the machine arm 2, perpendicular to the machine arm 2, and passes through the end of the machine arm 2. A sewing needle 52 is also installed at the bottom of the needle bar 5. The end of the main shaft 12 is fixedly installed with a needle bar cam 26 through a connecting piece. A needle bar driving crank 27 is rotatably connected to the end face of the needle bar cam 26. The other end of the needle bar driving crank 27 is rotatably connected to a needle bar driving connecting rod 25. The other end of the needle bar driving connecting rod 25 is connected to the needle bar 5. The needle bar 5 is also connected to the needle bar slider 241. The needle bar slider 241 is installed on the needle bar chute 242 of the needle bar slide 24. A needle bar guiding component 51 is also installed on the slider 24. The rod body of the needle bar 5 passes through the needle bar guiding component 51 and can slide along the track of the needle bar guiding component 51.

[0037] Before the thread 4 reaches the thread guide 23, it needs to be guided by thread adjusting and passing plates, thread clamping plates, and wire blocking hooks and other wire routing components. First, it bypasses the winding rod 232, and then passes through the first wire passing hole 223 located at the end of the front arm of the thread take-up lever near the front arm of the thread take-up lever. After passing through the first wire passing hole 223, the thread 4 reaches the winding rod cap 231, bypasses the winding rod cap 231, and then the thread passes through the second wire passing hole 223 and finally reaches the position of the sewing needle 52 of the needle bar 5 and passes through the eye of the sewing needle 52.

[0038] Under the continuous input power of the drive motor 3, the crank-rocker mechanism drives the thread take-up lever 22 to swing reciprocally periodically. Relative to the installation position of the thread take-up lever 22, the maximum angle that the thread take-up lever 22 can swing within one cycle is 25° - 30°. Under the action of the drive motor 3, finally, the thread take-up lever 22 drives the thread 4 to continuously supply the sewing needle 52. Since the thread take-up lever is connected to an independent drive source, that is, the drive motor 3, the thread supply mechanism of this sewing machine can be controlled by the control system of the sewing machine for independent thread feeding, and the running speed and thread supply amount can be adjusted independently according to different sewing processes and fabric thicknesses.

[0039] Compared with the prior art that usually supplies the thread by relying on the fixed speed operation of the main shaft, this design has higher flexibility and adaptability. Through this improvement, the thread supply amount can be increased by nearly twice on the original basis, continuously supply the thread material to the sewing needle, and thus more accurately control the timing of the thread material supply. This design significantly improves the working efficiency of the sewing machine and optimizes the overall quality of the sewn products.

[0040] Embodiment 2:

[0041] As Figure 1 shown, a thread feeding mechanism for a sewing machine, the main part of the thread feeding mechanism of the sewing machine consists of a machine base 1, a machine arm 2, and a drive motor 3, wherein the machine base 1 is vertically connected to the machine arm 2 and has a cantilever beam structure. When the thread feeding mechanism works, the thread 4 is connected to some structures on the machine arm 2, so as to realize the thread feeding, and the drive motor 3 is installed on the machine arm 2. In this embodiment, the drive motor 3 is installed on the bracket cover 21 at the other end face of the machine arm 2.

[0042] Different from the first embodiment, in the present embodiment, a spline is provided on the output end 31 of the driving motor 3, one end of the active crank 28 is a shaft sleeve 281, and a spline groove is processed on the inner wall of the center hole of the shaft sleeve 281, which cooperates with the spline of the output end 31 of the driving motor 3, and the output end 31 of the driving motor 3 is plugged into the center hole of the shaft sleeve 281 of the active crank 28, thereby realizing the transmission connection between the active crank 28 and the driving motor 3. In order to ensure the structural strength of the active crank 28, additional reinforcing ribs 284 are provided on both sides of the active crank 28, and in order to speed up the response speed of the thread take-up lever 22, a groove is processed on the end face of the active crank 283.

[0043] The thread take-up lever 22 includes a thread take-up lever shaft hole 221, a thread take-up lever connecting hole 222, and a thread passing hole 223. The thread take-up lever shaft hole 221 is located at one end of the thread take-up lever arm and is close to the thread take-up lever connecting hole 222. The thread take-up lever 22 is fixed to the thread take-up lever shaft 211 of the bracket cover 21 through the thread take-up lever shaft hole 221. The thread take-up lever 22 can be rotated relative to the bracket cover 21 through the thread take-up lever shaft hole 221. The bracket cover 21 is provided with a shaft for connecting with the thread take-up lever shaft hole 221 of the thread take-up lever 22, and the bracket cover 21 is also provided with a corresponding groove that can be placed in the thread take-up lever shaft hole 221. A rolling bearing is provided in the thread take-up lever shaft hole 221 to reduce the rotation friction of the thread take-up lever 22. The thread take-up lever 22 can be divided into a thread take-up lever arm and a thread take-up lever forearm, wherein the thread take-up lever shaft hole 221 and the thread take-up lever connecting hole 222 are arranged on the thread take-up lever arm, and the thread passing hole 223 is arranged on the thread take-up lever forearm. The thread take-up lever arm and the thread take-up lever forearm are L-shaped, the axis of the thread passing hole 223 is parallel to the thread take-up lever arm, and the axis of the thread take-up lever shaft hole 221 and the axis of the thread take-up lever connecting hole 222 are parallel to the thread take-up lever forearm.

[0044] The arm 2 is provided with a thread guide 23 on the outside, and a needle bar 5 and a needle bar slide 24 on the inside. The thread guide 23 is fixed on the outer shell of the arm 2, and the needle bar slide 24 is installed inside the arm 2. Needle bar slide grooves 242 are provided on both sides of the needle bar slide 24, and needle bar slides 241 are installed on the needle bar slide 242. The thread guide 23 is located below the thread take-up rod 22, and can further support and guide the face thread 4. The thread guide 23 includes a winding rod 232 and a winding cap 231. There is a matching relationship between the thread guide 23 and the thread take-up rod 22. The straight line matching between the thread guide 23 and the thread take-up rod 22 realizes the control of the path of the face thread. The face thread 4 extending from the thread routing component before the thread guide 23 passes through and returns between the thread take-up rod 22 and the thread guide 23 for many times, so that the tightness of the face thread 4 is more moderate.

[0045] The needle bar 5 is located inside the machine arm 2, perpendicular to the machine arm 2, and passes through the end of the machine arm 2. A sewing needle 52 is also installed at the bottom of the needle bar 5. The end of the main shaft 12 is fixedly installed with a needle bar cam 26 through a connecting piece. A needle bar driving crank 27 is rotatably connected to the end face of the needle bar cam 26. The other end of the needle bar driving crank 27 is rotatably connected to a needle bar driving connecting rod 25. The other end of the needle bar driving connecting rod 25 is connected to the needle bar 5. The needle bar 5 is also connected to a needle bar slider 241. The needle bar slider 241 is installed on a needle bar chute 242 of a needle bar slide base 24. A needle bar guiding assembly 51 is also installed on the slider 24. The rod body of the needle bar 5 passes through the needle bar guiding assembly 51 and can slide along the track of the needle bar guiding assembly 51.

[0046] Before the thread 4 reaches the thread guide 23, it needs to be guided by threading components such as a thread adjusting and guiding plate, a thread clamping plate, and a stop hook. First, it bypasses the winding rod 232, and then passes through the first thread passing hole 223 located at the end of the front arm of the thread take-up lever near the front arm of the thread take-up lever. After passing through the first thread passing hole 223, the thread 4 reaches the winding rod cap 231. After bypassing the winding rod cap 231, the thread passes through the second thread passing hole 223 and finally reaches the position of the sewing needle 52 of the needle bar 5 and passes through the eye of the sewing needle 52.

[0047] With the continuous input of power from the driving motor 3, the crank-rocker mechanism drives the thread take-up lever 22 to swing reciprocally periodically. Relative to the installation position of the thread take-up lever 22, the maximum angle that the thread take-up lever 22 can swing within one cycle is 25° - 30°. Under the action of the driving motor 3, finally, the thread take-up lever 22 drives the thread 4 to continuously supply the sewing needle 52.

[0048] Embodiment 3:

[0049] Different from Embodiment 1 and Embodiment 2, the thread guide 23 in this embodiment is replaced with a thread hook 6. Two winding holes 61 are provided on the thread hook 6. After the thread 4 reaches the position of the thread hook 6, it passes through the first winding hole 61, passes through the first thread passing hole 223 of the thread take-up lever 22 after passing through, then passes through the second winding hole 61, passes through the second thread passing hole 223 again, and finally reaches the position of the sewing needle 52 of the needle bar and passes through the eye of the sewing needle 52.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sewing machine upper thread supply mechanism, comprising a machine arm (2), a main shaft (12) being provided on the machine arm (2), a main shaft motor (11) connected to the main shaft (12) and a driving motor (3), characterized in that ； A thread take-up lever (22) is installed on the machine arm (2); The output end (31) of the driving motor (3) is transmission-connected to the thread take-up lever (22); The thread taking-up lever (22) is provided with a plurality of thread passing holes (223).

2. The upper thread supply mechanism for a sewing machine according to claim 1, characterized in that; The driving motor (3) is mounted on the machine arm (2); The output end (31) of the driving motor (3) is connected to one end of the active crank (28), the other end of the active crank (28) is connected to one end of the connecting rod (29), and the other end of the connecting rod (29) is connected to the thread take-up rod (22).

3. The upper thread supply mechanism for a sewing machine according to claim 2, characterized in that: The connecting rod (29) is connected to the connecting hole (222) of the thread take-up rod (22).

4. The upper thread supply mechanism for a sewing machine according to any one of claims 1 to 3, characterized in that: The machine arm (2) is provided with a wire passing hook (6), and the wire passing hook is provided with a plurality of wire winding holes (61).

5. The upper thread supply mechanism for a sewing machine according to claim 2, characterized in that: A shaft sleeve (281) is installed at one end of the active crank (28), and a plurality of fixing holes (282) are arranged outside the shaft sleeve (281), and the fixing holes (282) pass through the center hole of the shaft sleeve (281).

6. The upper thread supply mechanism for a sewing machine according to claim 2, characterized in that: A reinforcing rib (284) is provided on the side surface of the active crank (28).

7. The upper thread supply mechanism for a sewing machine according to claim 2, characterized in that: The end surface of the active crank (28) is provided with a groove (283).

8. The upper thread supply mechanism for a sewing machine according to any one of claims 1 to 3, characterized in that: A thread take-up lever rotating shaft hole (221) is provided at one end of the thread take-up lever (22), a thread take-up lever shaft (211) is provided on the bracket cover (21) of the machine arm (2), and the thread take-up lever shaft (211) is connected to the thread take-up lever rotating shaft hole (221).

9. The upper thread supply mechanism for a sewing machine according to any one of claims 1 to 3, characterized in that: A thread guide (23) is provided on the machine arm (2), and the thread guide (23) is located below the thread take-up lever (22).

10. The upper thread supply mechanism for a sewing machine according to claim 1 or 2 or 3 or 5 or 6 or 7, characterized in that: The thread take-up lever (22) swings on the machine arm (2) with a swing range of 20 to 35 degrees.

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