Thread trimming mechanism and sewing machine with same

Abstract

The utility model provides a thread trimming mechanism and a sewing machine with the same. The thread trimming mechanism comprises a first movable cutter which comprises a thread clamping part and a first cutting edge part; the second movable cutter is arranged on one side of the first movable cutter, and the second movable cutter comprises a thread collecting groove and a second cutting edge part, and the thread collecting groove is used for allowing the upper threads to penetrate through; the second cutting edge part is located on the side, away from the first movable cutter, of the line concentration groove and faces a groove opening of the line concentration groove. The first cutting edge part is located on the side, away from the second movable cutter, of the thread clamping part and faces the thread clamping part. Wherein the second movable cutter is movably arranged in the direction close to or away from the first movable cutter so as to move to a thread clamping position where a clamping gap used for clamping an upper thread is formed between the thread clamping part and the second cutting edge part or a thread cutting position where the first cutting edge part and the second cutting edge part are in contact to cut off the upper thread. According to the technical scheme provided by the utility model, the technical problem that bird nest stitches are easily formed when a sewing machine in the prior art starts sewing can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of thread trimming mechanisms, in particular to a thread trimming mechanism and a sewing machine having the same. Background Art

[0002] Currently, during the initial seam start-up operation on a sewing machine, due to the instability of the initial stitch, the upper thread, under the action of the rotary hook, easily intertwines with the lower thread and becomes entangled beneath the sewing material, forming loose and messy clumps of thread of varying sizes, the so-called "bird's nest stitch." This stitch not only looks rough but can also affect the quality of subsequent stitches, reducing the seam's strength and posing a potential threat to the quality of the finished garment.

[0003] However, existing technologies address the bird's nest stitch problem primarily through manual intervention and mechanical device improvements. While manual bird's nest stitch removal can achieve a certain degree of success, it increases operator workload, significantly increases labor costs, and reduces production efficiency. While existing bird's nest thread trimming devices can automate the removal of bird's nest stitches to a certain extent, in practice, their thread clamping and trimming operations are complex, involving the coordination of multiple movable knives, which affects sewing efficiency. Utility Model Content

[0004] The main purpose of the utility model is to provide a thread trimming mechanism and a sewing machine with the same, so as to solve the technical problem in the prior art that the sewing machine is prone to forming bird's nest stitches when sewing.

[0005] In order to achieve the above object, according to one aspect of the present invention, a thread trimming mechanism is provided, comprising:

[0006] The first movable knife comprises a line clamping portion and a first cutting edge portion;

[0007] A second movable knife is arranged on one side of the first movable knife, the second movable knife including a wire collecting groove for passing the upper thread and a second cutting edge portion; the second cutting edge portion is located on a side of the wire collecting groove away from the first movable knife, and the second cutting edge portion is arranged toward the notch of the wire collecting groove; the first cutting edge portion is located on a side of the wire clamping portion away from the second movable knife, and the first cutting edge portion is arranged toward the wire clamping portion;

[0008] In which, the second movable knife is movably arranged in a direction approaching or moving away from the first movable knife, so as to move to a clamping position in which a clamping gap for clamping the face line is formed between the clamping portion and the second cutting edge portion, or to a cutting position in which the first cutting edge portion and the second cutting edge portion are in contact to cut the face line.

[0009] Furthermore, at least a portion of the second cutting edge portion is located at the slot opening of the cable collection slot.

[0010] Furthermore, the line collection slot includes a first slot section and a second slot section connected to each other, and the second slot section is located on a side of the first slot section close to the second cutting edge portion;

[0011] Wherein, along the depth direction of the cable collection slot, the cross-sectional area of ​​the second slot section is smaller than the cross-sectional area of ​​the first slot section; and / or,

[0012] The cable collection trough is an arc-shaped trough.

[0013] Furthermore, the second movable knife also includes a needle groove for allowing the machine needle to pass through, and the needle groove is located on the side of the second cutting edge portion away from the wire collection groove.

[0014] Furthermore, the second movable knife further includes:

[0015] The limiting portion is arranged on a side of the second cutting edge portion away from the needle groove and toward the second cutting edge portion, and the limiting portion protrudes from the outer edge of the wire collecting groove.

[0016] Furthermore, the first movable knife further includes:

[0017] The abutment portion is arranged on one side of the line clamping portion and protrudes from the line clamping portion; the abutment portion is used to abut against at least a portion of the second movable knife.

[0018] Furthermore, the first movable knife further includes:

[0019] The wire portion is located on the side of the wire clamping portion away from the first cutting edge portion; the second movable knife also has a wire initial position and a wire end position; when the second movable knife is in the wire initial position, at least part of the wire collecting groove is arranged relative to at least part of the wire portion, so that the surface wire in the wire collecting groove contacts the wire portion; when the second movable knife is in the wire end position, at least part of the wire portion is arranged relative to the second cutting edge portion, so that the surface wire in the wire collecting groove contacts the second cutting edge portion.

[0020] Furthermore, the first movable knife further includes a third cutting edge portion, which is arranged on a side of the first cutting edge portion away from the line clamping portion and facing the second movable knife;

[0021] The second movable knife further includes a fourth cutting edge portion, which is located on a side of the cable collection slot away from the second cutting edge portion and is arranged toward the first movable knife;

[0022] The first movable knife is movably arranged in a direction close to or away from the second movable knife to move to a post-sewing thread cutting position where the third cutting edge portion and the fourth cutting edge portion are in contact or to an avoidance position where the third cutting edge portion and the fourth cutting edge portion avoid each other.

[0023] Furthermore, the first movable knife and the second movable knife are both arc-shaped structures; the thread cutting mechanism further includes a first rotating member and a second rotating member, the first movable knife is arranged on the first rotating member, and the first rotating member is rotatably arranged along a preset rotating axis; the second movable knife is arranged on the second rotating member, and the second rotating member is rotatably arranged along the preset rotating axis; and / or,

[0024] The thread trimming mechanism further comprises an air suction structure, wherein an air suction end of the air suction structure is arranged toward the first cutting edge portion.

[0025] According to another aspect of the present invention, a sewing machine is provided, comprising: the thread trimming mechanism provided above.

[0026] The application of the technical solution of the present invention can firstly reduce the generation of bird's nest stitches. During the seam-starting stage, the thread collecting groove of the second movable knife can accurately capture the upper thread ends left after the needle pierces the fabric, facilitating the subsequent clamping and shearing of the opposite thread ends. At the same time, during the movement of the second movable knife toward the first movable knife, a clamping gap for clamping the upper thread can be formed between the thread clamping portion and the second cutting edge portion, so that the upper thread can be stably clamped, effectively avoiding the upper thread from being derailed due to improper movement during the seam-starting stage, and ensuring the continuity and aesthetics of the subsequent stitches. Secondly, after the upper thread is clamped, during the further movement of the second movable knife toward the first movable knife, the first cutting edge portion and the second cutting edge portion can contact and engage with each other, thereby achieving rapid and clean shearing of the opposite thread ends, avoiding thread ends remaining during the thread cutting process, and improving thread cutting efficiency and sewing quality. This solution effectively reduces the generation of bird's nest stitches during the seam-starting stage by setting up two movable knives. Compared with the existing technology, the operation steps of the double-knife cooperation are simpler and more efficient, and do not require additional fixed knife assistance. Therefore, the technical solution of the present invention can solve the technical problem in the prior art that a sewing machine easily forms a bird's nest stitch when sewing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting part of this application are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 FIG2 shows a structural schematic diagram of a thread trimming mechanism provided according to the first embodiment of the present utility model;

[0029] Figure 2 FIG2 shows a schematic structural diagram of a first movable knife of a thread trimming mechanism provided in accordance with the first embodiment of the present utility model;

[0030] Figure 3 FIG2 shows a schematic structural diagram of a second movable knife of a thread trimming mechanism according to the first embodiment of the present invention;

[0031] Figure 4 A schematic diagram showing the matching relationship between the needle and the thread collecting groove of the thread trimming mechanism provided in the first embodiment of the present utility model is shown;

[0032] Figure 5 A schematic diagram showing the matching relationship between the needle and the needle slot of the thread trimming mechanism provided in embodiment 1 of the present invention is shown.

[0033] The above drawings include the following reference numerals:

[0034] 10. First movable knife;

[0035] 101, third cutting edge;

[0036] 102, first cutting edge portion;

[0037] 103, clamping part;

[0038] 104, wire portion;

[0039] 105. Contact part;

[0040] 20. Second movable knife;

[0041] 201, fourth cutting edge;

[0042] 202, second cutting edge portion;

[0043] 203, cable trough;

[0044] 2031, first slot section; 20311, first end; 20312, second end;

[0045] 2032, second slot section; 20321, third end; 20322, fourth end;

[0046] 2033, notch;

[0047] 204, through the needle groove;

[0048] 205, limit part;

[0049] 30. Machine needle;

[0050] 40. Air suction structure;

[0051] 50. First rotating member;

[0052] 51. First mounting portion;

[0053] 60. Second rotating member;

[0054] 61. Second mounting portion;

[0055] 70. First drive structure;

[0056] 80. Second drive structure. DETAILED DESCRIPTION

[0057] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] like Figures 1 to 5 As shown, embodiment 1 of the present invention provides a thread trimming mechanism, which includes a first movable knife 10 and a second movable knife 20. The first movable knife 10 includes a thread clamping portion 103 and a first cutting edge portion 102. The second movable knife 20 is arranged on one side of the first movable knife 10, and the second movable knife 20 includes a thread collecting groove 203 for passing the surface thread and a second cutting edge portion 202; the second cutting edge portion 202 is located on the side of the thread collecting groove 203 away from the first movable knife 10, and the second cutting edge portion 202 is arranged toward the notch 2033 of the thread collecting groove 203; the first cutting edge portion 102 is located on the side of the thread clamping portion 103 away from the second movable knife 20, and the first cutting edge portion 102 is arranged toward the thread clamping portion 103. Among them, the second movable knife 20 is movably arranged in a direction close to or away from the first movable knife 10, so as to move to a clamping position in which a clamping gap for clamping the surface line is formed between the clamping portion 103 and the second cutting edge portion 202, or to a cutting position in which the first cutting edge portion 102 and the second cutting edge portion 202 contact to cut the surface line.

[0059] The thread cutting mechanism provided by the first embodiment of the present invention can firstly reduce the generation of bird's nest stitches. In the sewing stage, the thread collecting groove 203 of the second movable knife 20 can accurately capture the upper thread end left after the needle 30 pierces the fabric, facilitating the subsequent clamping and shearing of the opposite thread end. At the same time, in the process of the second movable knife 20 moving toward the first movable knife 10, a clamping gap for clamping the upper thread can be formed between the thread clamping portion 103 and the second cutting edge portion 202, so that the upper thread can be stably clamped, effectively avoiding the upper thread from being derailed due to improper movement in the sewing stage, and ensuring the continuity and aesthetics of the subsequent stitches. Secondly, after the upper thread is clamped, in the process of the second movable knife 20 further moving toward the first movable knife 10, the first cutting edge portion 102 and the second cutting edge portion 202 can contact and engage with each other, thereby achieving quick and clean shearing of the opposite thread end, avoiding thread end residue during the thread cutting process, and improving thread cutting efficiency and sewing quality. This solution effectively reduces the formation of bird's nest stitches when starting a seam by providing two movable knives. Compared with the existing technology, the operation steps of the two knives are simpler and more efficient, and no additional fixed knife is required. Therefore, the thread trimming mechanism provided by this embodiment can solve the technical problem of the existing sewing machine that easily forms bird's nest stitches when starting a seam.

[0060] Specifically, if Figure 1As shown, before the second movable knife 20 starts to move in a direction close to the first movable knife 10 , the first movable knife 10 and the second movable knife 20 are respectively located on both sides of the needle 30 .

[0061] Specifically, the wire collecting groove 203 and the second cutting edge portion 202 are interconnected. With this structural arrangement, the interconnection between the wire collecting groove 203 and the second cutting edge portion 202 enables the upper thread to quickly contact the second cutting edge portion 202 when being guided through the wire collecting groove 203. This provides a basis for stable positioning of the upper thread and subsequent cutting, reduces movement of the upper thread before cutting, improves operating efficiency, and effectively avoids the generation of chaotic stitches and bird's nest stitches.

[0062] Specifically, at least a portion of the second cutting edge portion 202 is located at the notch 2033 of the thread collecting groove 203. This ensures that after the upper thread is guided out of the thread collecting groove 203, the second cutting edge portion 202 can quickly align with the upper thread, thereby improving the accuracy and efficiency of cutting the upper thread, avoiding position deviation of the upper thread during cutting, and thus improving the thread cutting effect and the aesthetics of the finished sewing product.

[0063] Specifically, the thread collecting groove 203 includes a first groove section 2031 and a second groove section 2032, which are connected to each other. The second groove section 2032 is located on the side of the first groove section 2031 closer to the second cutting edge 202. With this structural arrangement, the second groove section 2032 provides a smooth path for the upper thread to contact the second cutting edge 202, reducing upper thread jamming and resistance during the guiding process, thereby ensuring stitch continuity and sewing efficiency.

[0064] Specifically, along the depth of the thread collecting groove 203, the cross-sectional area of ​​the second groove section 2032 is smaller than that of the first groove section 2031. This structural arrangement facilitates the precise positioning of the upper thread in the second groove section 2032. The reduced cross-sectional area allows for a tighter positioning of the upper thread, thereby providing more stable and precise cutting conditions during thread trimming, reducing loose thread ends during the cutting process, and ensuring accurate trimming and upper thread continuity.

[0065] It should be noted that the depth direction of the cable collecting groove 203 is the thickness direction of the second movable blade 20 .

[0066] Specifically, the wire collecting groove 203 is an arc-shaped groove. Thus, through the guiding effect of the arc-shaped groove, the upper thread can transition more naturally and smoothly to the second cutting edge portion 202, reducing the possibility of thread breakage or damage caused by right-angle turns. At the same time, the arc-shaped design helps to reduce thread residue in the groove, improving the cleaning efficiency of the thread trimming mechanism.

[0067] Specifically, the first slot section 2031 extends along a first preset direction, and the second slot section 2032 extends along a second preset direction, and the angle between the first preset direction and the second preset direction is greater than or equal to 90 degrees and less than 180 degrees. The first preset direction is the direction from the first end 20311 to the second end 20312 of the first slot section 2031, and the second preset direction is the direction from the third end 20321 to the fourth end 20322 of the second slot section 2032. With this structural arrangement, the upper thread can move naturally between the first slot section 2031 and the second slot section 2032 after entering the thread collecting slot 203, avoiding thread jamming or breakage caused by a sharp turn. It also facilitates the positioning and cutting of the upper thread during thread trimming, improving the accuracy and reliability of thread trimming, further optimizing stitch management in the initial sewing stage, and enhancing sewing quality.

[0068] In this embodiment, the second movable blade 20 further includes a needle slot 204 for the needle to pass through. The needle slot 204 is located on the side of the second cutting edge 202 away from the thread collecting slot 203. With this structural arrangement, the design of the needle slot 204 in the second movable blade 20 allows the needle 30 to pass through smoothly during the sewing process, achieving normal interweaving of the upper thread and the lower thread, thereby avoiding the problem of upper thread derailment or discontinuous stitching caused by the conflict between the needle 30 and the blade structure, and improving the stability of sewing and the aesthetic quality of the stitching.

[0069] Specifically, the second movable knife 20 also includes a limiting portion 205, which is arranged on the side of the second cutting edge portion 202 away from the needle groove 204 and toward the second cutting edge portion 202, and the limiting portion 205 protrudes from the outer edge of the wire collecting groove 203. The portion of the limiting portion 205 protruding from the outer edge of the wire collecting groove 203 is used to limit the upper thread end located at the groove 2033. With such a structural arrangement, the setting of the limiting portion 205 further limits the movement range of the upper thread, ensuring that the upper thread is accurately clamped in the sewing stage, reducing the possibility of chaotic stitches. In the sewing stage, the limiting portion 205 limits the upper thread end that passes through the wire collecting groove 203, ensuring that the upper thread can be accurately clamped in the predetermined position when in contact with the thread clamping portion 103, avoiding excessive movement of the upper thread or deviation from the predetermined trajectory, reducing the chance of forming bird's nest stitches, and improving the clarity and firmness of the stitches in the initial stage of sewing.

[0070] Specifically, the first movable knife 10 also includes an abutment portion 105, which is arranged on one side of the thread clamping portion 103 and protrudes from the thread clamping portion 103; the abutment portion 105 is used to abut at least part of the second movable knife 20 to expand the clamping gap. With such a structural arrangement, the abutment portion 105 can contact a specific part of the second movable knife 20. The abutment effect of the abutment portion 105 on the second movable knife 20 can adjust the relative position between the two knives, so that the clamping gap can be expanded. This gap adjustment mechanism plays a key role in the thread cutting process. When the clamped thread end needs to be released for normal shearing, the part of the abutment portion 105 protruding from the thread clamping portion 103 can lift the second movable knife 20, thereby expanding the clamping gap and allowing the surface thread to smoothly break away from the clamping state, making it easier to be cut, thus ensuring a smooth sewing process.

[0071] In this embodiment, the first movable knife 10 also includes a wire portion 104, which is located on the side of the wire clamping portion 103 away from the first cutting edge portion 102; the second movable knife 20 also has a wire initial position and a wire end position; when the second movable knife 20 is in the wire initial position, at least part of the wire collecting groove 203 is arranged relative to at least part of the wire portion 104, so that the surface wire in the wire collecting groove 203 contacts the wire portion 104; when the second movable knife 20 is in the wire end position, at least part of the wire portion 104 is arranged relative to the second cutting edge portion 202, so that the surface wire in the wire collecting groove 203 contacts the second cutting edge portion 202. With such a structural setting, the dynamic cooperation between the wire guide portion 104 of the first movable knife 10 and the wire collecting groove 203 of the second movable knife 20 enables the upper thread to be stably guided and positioned at the beginning stage of sewing. When the second movable knife 20 moves from the initial wire guide position to the end wire guide position, the upper thread transitions from contact with the wire guide portion 104 to contact with the second cutting edge portion 202. No human intervention is required, and the guidance and stabilization process of the stitches is automatically completed, which significantly improves the initial quality and consistency of the sewing stitches, reduces the formation of bird's nest stitches, and improves sewing efficiency.

[0072] Specifically, the first movable knife 10 also includes a third cutting edge portion 101, which is disposed on a side of the first cutting edge portion 102 away from the thread clamping portion 103 and facing the second movable knife 20. The second movable knife 20 also includes a fourth cutting edge portion 201, which is located on a side of the thread collecting groove 203 away from the second cutting edge portion 202 and facing the first movable knife 10. The first movable knife 10 is movably disposed in a direction toward or away from the second movable knife 20, so as to move to a post-sewing thread cutting position in which the third cutting edge portion 101 and the fourth cutting edge portion 201 come into contact, or to a retracting position in which the third cutting edge portion 101 and the fourth cutting edge portion 201 are retracted. With this structural arrangement, at the end of sewing, the relative movement between the third cutting edge portion 101 of the first movable knife 10 and the fourth cutting edge portion 201 of the second movable knife 20 achieves precise cutting of the top and bottom threads. This design enables the thread trimming mechanism to quickly and accurately cut the upper and lower threads after sewing is completed, and the double-knife thread trimming position is close to the bottom of the needle 30, so that the length of the thread ends left on the fabric is shorter.

[0073] In this embodiment, the first movable blade 10 and the second movable blade 20 both have an arc-shaped structure. The thread trimming mechanism also includes a first rotating member 50 and a second rotating member 60. The first movable blade 10 is disposed on the first rotating member 50, which is rotatable along a preset rotation axis. The second movable blade 20 is disposed on the second rotating member 60, which is rotatable along a preset rotation axis. This ensures the smoothness and precision of the tool movement. At the same time, the arc-shaped design helps reduce the impact of the tool during the shearing process, reduces noise during the thread trimming process, reduces tool wear, and extends the service life of the thread trimming mechanism. The use of rotating members enables the tool to rotate precisely along the preset axis, realizing the rapid transition of the thread trimming mechanism between different working states. In addition, this arrangement effectively improves the structural compactness of the thread trimming mechanism, reduces the volume of the mechanism, and improves its ease of use.

[0074] Specifically, the first movable blade 10 is disposed on the first mounting portion 51 of the first rotating member 50 , and the second movable blade 20 is disposed on the second mounting portion 61 of the second rotating member 60 .

[0075] Specifically, the first drive structure 70 is drivingly connected to the first rotating member 50, and the second drive structure 80 is drivingly connected to the second rotating member 60. Both the first drive structure 70 and the second drive structure 80 are connecting rod mechanisms. Thus, the two drive structures drive the first rotating member 50 and the second rotating member 60, respectively, effectively improving the precision of the shearing operation.

[0076] Specifically, the thread trimmer mechanism further includes a suction structure 40, the suction end of which is disposed toward the first cutting edge 102. This structural arrangement ensures that the severed thread ends are quickly sucked away at the instant they are cut, preventing residual thread ends from affecting subsequent sewing or cleaning work, thereby improving the efficiency of the thread trimmer mechanism. It also maintains a clean working area of ​​the sewing machine, reduces the impact of thread blockage on the operation of the sewing machine, and enhances the operator's working environment comfort.

[0077] A second embodiment of the present invention provides a sewing machine, which includes the thread trimming mechanism provided in the first embodiment.

[0078] The sewing machine provided by the second embodiment of the present invention can firstly reduce the generation of bird's nest stitches. In the sewing stage, the thread collecting groove 203 of the second movable knife 20 can accurately capture the upper thread end left after the needle 30 pierces the fabric, which is convenient for the subsequent clamping and shearing of the opposite thread end. At the same time, in the process of the second movable knife 20 moving toward the first movable knife 10, a clamping gap for clamping the upper thread can be formed between the thread clamping portion 103 and the second cutting edge portion 202, so that the upper thread can be stably clamped, effectively avoiding the upper thread from being derailed due to improper movement in the sewing stage, and ensuring the continuity and aesthetics of the subsequent stitches. Secondly, after the upper thread is clamped, in the process of the second movable knife 20 further moving toward the first movable knife 10, the first cutting edge portion 102 and the second cutting edge portion 202 can contact and bite each other, thereby achieving fast and clean shearing of the opposite thread end, avoiding thread end residue during the thread cutting process, and improving thread cutting efficiency and sewing quality. This solution effectively reduces the formation of bird's nest stitches when starting a seam by providing two movable knives. Compared with the existing technology, the operation steps of the two knives are simpler and more efficient, and no additional fixed knife is required. Therefore, the sewing machine provided by this embodiment can solve the technical problem of the existing sewing machine that is prone to forming bird's nest stitches when starting a seam.

[0079] Specifically, the working principle of this solution includes the following process: 1. At the beginning of seam starting and before the needle 30 moves to the bottom of the needle plate, the second movable knife 20 moves toward the first movable knife 10, causing the thread collecting groove 203 to move directly below the needle 30. The needle 30 carries the upper thread through the thread collecting groove 203, forming a thread loop below the second movable knife 20. Under the action of the rotary hook, the upper thread end is brought to the bottom of the second movable knife 20; 2. When the needle 30 moves out of the second movable knife 20 to the appropriate position, the second movable knife 20 continues to move toward the first movable knife 10. Under the combined action of the thread collecting groove 203 and the guide wire portion 104, the upper thread end moves to the junction of the thread collecting groove 203 and the second cutting edge portion 202. Afterwards, the second cutting edge portion 202 of the second movable knife 20 contacts the thread clamping portion 103 of the first movable knife, so that the upper thread end is clamped but not cut. Among them, the limiting part 205 of the second movable knife 20 serves to limit the movement range of the upper thread, ensuring that the upper thread can be accurately clamped at the thread clamping part 103; 3. When the upper thread end is clamped, the needle groove 204 of the second movable knife 20 just moves to the bottom of the needle 30. When the upper thread is clamped, the needle 30 continues to move up and down until several stitches are sewn. After that, the needle 30 is lifted to the appropriate position, and the second movable knife 20 continues to move toward the direction of the first movable knife 10. At this time, since the fourth cutting edge 201 of the second movable knife 20 begins to contact the abutment part 105 of the first movable knife 10, the second movable knife 20 is slightly lifted, and the upper thread leaves the clamped state. Finally, under the bite action of the second cutting edge 202 of the second movable knife 20 and the first cutting edge 102 of the first movable knife 10, the upper thread is cut. During this process, the suction mechanism 40 is activated to suck away the cut upper thread end; 4. After the upper thread is cut, the second movable knife 20 returns to its original position, and then enters the normal sewing process. During the entire anti-bird nest action process, the first movable knife 10 remains stationary.

[0080] Specifically, the operating principle of this solution also includes the post-sewing thread trimming process: upon receiving the thread trimming signal, the first movable knife 10 moves toward the second movable knife 20, and the third cutting edge 101 of the first movable knife 10 engages with the fourth cutting edge 201 of the second movable knife 20, cutting the upper and lower threads. During this post-sewing thread trimming process, the second movable knife 20 can remain stationary or rotate a short distance toward the first movable knife 10, bringing the fourth cutting edge 201 closer to the bottom of the needle 30, thereby shortening the length of the thread remaining on the fabric.

[0081] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0082] 1. Significantly reduce bird's nest stitches: Through precise tool design and dynamic matching mechanism, this solution can effectively avoid the intertwining and entanglement of the upper and lower threads at the beginning of sewing, significantly reducing the occurrence of bird's nest stitches, improving the appearance quality and structural firmness of the sewn products, and meeting the quality requirements of clothing with high sewing requirements.

[0083] 2. Prevent the upper thread from coming off: The unique limiter design and the precise positioning mechanism of the thread collecting groove and the second cutting edge ensure that the upper thread is stably clamped during the sewing stage, effectively preventing the upper thread from coming off, ensuring the continuity and integrity of the sewing seams and improving sewing efficiency.

[0084] 3. Improved efficiency: The anti-bird nest design reduces the messy bird nest stitches at the beginning of sewing, greatly reduces the workload of manual trimming in the later stage, and significantly improves production efficiency.

[0085] 4. Improved automation: This solution realizes the automation of seam starting and thread trimming through the automatic coordination of the integrated suction structure and the cutter, which greatly reduces the labor intensity of the operator, reduces the impact of human factors on sewing quality, and improves the automation level and overall production efficiency of the sewing machine.

[0086] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0087] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0088] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0089] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figures. For example, if the device in the drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0090] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A thread trimming mechanism, characterized in that: include: A first movable knife (10) includes a line clamping portion (103) and a first cutting edge portion (102); a second movable knife (20) disposed on one side of the first movable knife (10), the second movable knife (20) comprising a wire collecting groove (203) for passing the surface thread and a second cutting edge portion (202); the second cutting edge portion (202) being located on a side of the wire collecting groove (203) away from the first movable knife (10), and the second cutting edge portion (202) being disposed toward a notch (2033) of the wire collecting groove (203); the first cutting edge portion (102) being located on a side of the wire clamping portion (103) away from the second movable knife (20), and the first cutting edge portion (102) being disposed toward the wire clamping portion (103); The second movable knife (20) is movably arranged in a direction approaching or moving away from the first movable knife (10) to move to a clamping position where a clamping gap for clamping the face thread is formed between the thread clamping portion (103) and the second cutting edge portion (202) or to a thread cutting position where the first cutting edge portion (102) and the second cutting edge portion (202) are in contact to cut the face thread.

2. The thread trimming mechanism according to claim 1, characterized in that: At least a portion of the second cutting edge portion (202) is located at the notch (2033) of the wire collection slot (203).

3. The thread trimming mechanism according to claim 1, characterized in that: The line collection slot (203) comprises a first slot section (2031) and a second slot section (2032) connected to each other, wherein the second slot section (2032) is located on a side of the first slot section (2031) close to the second cutting edge portion (202); Wherein, along the groove depth direction of the line collection groove (203), the cross-sectional area of ​​the second groove section (2032) is smaller than the cross-sectional area of ​​the first groove section (2031); and / or, The line collection slot (203) is an arc-shaped slot.

4. The thread trimming mechanism according to claim 1, characterized in that: The second movable knife (20) further comprises a needle slot (204) for allowing a machine needle to pass through, and the needle slot (204) is located on a side of the second cutting edge portion (202) away from the wire collection slot (203).

5. The thread trimming mechanism according to claim 4, characterized in that: The second movable knife (20) further comprises: A limiting portion (205) is arranged on a side of the second cutting edge portion (202) away from the needle groove (204) and toward the second cutting edge portion (202), and the limiting portion (205) protrudes from the outer edge of the wire collecting groove (203).

6. The thread trimming mechanism according to claim 1, characterized in that: The first movable knife (10) further comprises: The abutment portion (105) is provided on one side of the line clamping portion (103), and the abutment portion (105) is protruding from the line clamping portion (103); the abutment portion (105) is used to abut against at least a portion of the second movable knife (20).

7. The thread trimming mechanism according to claim 1, characterized in that: The first movable knife (10) further comprises: The wire portion (104) is located on a side of the wire clamping portion (103) away from the first cutting edge portion (102); the second movable knife (20) also has a wire initial position and a wire end position; when the second movable knife (20) is in the wire initial position, at least a portion of the wire collecting groove (203) is arranged relative to at least a portion of the wire portion (104), so that the surface wire in the wire collecting groove (203) contacts the wire portion (104); when the second movable knife (20) is in the wire end position, at least a portion of the wire portion (104) is arranged relative to the second cutting edge portion (202), so that the surface wire in the wire collecting groove (203) contacts the second cutting edge portion (202).

8. The thread trimming mechanism according to claim 1, characterized in that: The first movable knife (10) further comprises a third cutting edge portion (101), wherein the third cutting edge portion (101) is arranged on a side of the first cutting edge portion (102) away from the line clamping portion (103) and is arranged toward the second movable knife (20); The second movable knife (20) further comprises a fourth cutting edge portion (201), wherein the fourth cutting edge portion (201) is located on a side of the cable collection slot (203) away from the second cutting edge portion (202) and is arranged toward the first movable knife (10); The first movable knife (10) is movably arranged in a direction approaching or moving away from the second movable knife (20) so as to move to a post-sewing thread cutting position where the third cutting edge portion (101) and the fourth cutting edge portion (201) are in contact with each other or to an avoidance position where the third cutting edge portion (101) and the fourth cutting edge portion (201) avoid each other.

9. The thread trimming mechanism according to claim 1, characterized in that: The first movable knife (10) and the second movable knife (20) are both arc-shaped structures; the thread cutting mechanism further includes a first rotating member (50) and a second rotating member (60), the first movable knife (10) is arranged on the first rotating member (50), and the first rotating member (50) is rotatably arranged along a preset rotating axis; the second movable knife (20) is arranged on the second rotating member (60), and the second rotating member (60) is rotatably arranged along the preset rotating axis; and / or, The thread trimming mechanism further comprises an air suction structure (40), wherein the air suction end of the air suction structure (40) is arranged toward the first cutting edge portion (102).

10. A sewing machine, characterized in that: include: The thread trimming mechanism according to any one of claims 1 to 9.

Images