Sewing machine left thread hook assembly and sewing machine

Abstract

The utility model relates to the technical field of sewing machines, in particular to a left thread hook assembly of a sewing machine, which comprises a fixed part and a left thread hook, the fixed part is fixed on a machine head of the sewing machine and positioned on one side of a needle of a take-up lever, and an elastic reset part on the fixed part is connected with the left thread hook. The left thread hook is arranged on the fixing piece in the mode that the left thread hook can transversely move towards one side of a thread clamping device of the take-up-lever, the left thread hook is provided with an upper guiding part, a lower guiding part and an elastic part, the upper guiding part and the lower guiding part are both used for an upper thread to penetrate through and guide the upper thread towards the needle hole direction, and the upper guiding part and the lower guiding part are flexibly connected from high to low. The lower guide part can be reset under the action of the elastic part; the utility model further discloses the sewing machine adopting the left thread hook assembly of the sewing machine. The left thread hook assembly can improve the tension of a thread channel, and after the tension of the thread channel is reduced, the sewing problems of thread breakage, stitch skipping and the like can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, and in particular to a left thread hook assembly for a sewing machine, and a sewing machine using the left thread hook assembly. Background Technology

[0002] During the stitch formation process in a sewing machine, if interference factors such as thread friction are ignored, when the top thread begins to tighten, the tension generated by the stitch locking at the fabric end, the tension generated by the thread clamp at the thread holder end, and the thread take-up lever exerting a take-up force on the top thread together constitute a set of balanced forces. However, as feeding continues, the take-up mechanism needs to quickly pull the top thread from the thread holder to continuously replenish the thread supply for stitch formation. This rapid pulling of the top thread disrupts the force balance, causing the internal tension of the top thread to increase rapidly or even abruptly. Especially in sewing processes such as overlocking, the fabric thickness increases dramatically, and the required amount of top thread also increases dramatically. The take-up mechanism cannot keep up with the demand for top thread, so the top thread can only compensate for the required amount of thread by tightening and stretching its internal tension. At this point, the more thread guides there are between the thread tensioner and the needle, the more complex the thread path becomes; the more bends and turns there are, the more times the tension changes; the larger the turning angle, the greater the range of tension changes, which can lead to problems such as skipped stitches and broken threads.

[0003] Currently, in terms of thread optimization, invention patent CN101220548A proposes a thread guiding component, including a fixing part, a guiding part, and an elastic part. The elastic part can elastically deform according to changes in thread tension, thereby allowing the thread tension to vary within a certain range. Even under drastic changes in sewing conditions, it can maintain thread stability and avoid problems such as thread breakage. However, the aforementioned thread guiding component is essentially an improvement on the thread hook of the lower bushing of the needle bar on a sewing machine, and is only suitable for solving the problems of skipped stitches and thread breakage caused by the thread hook of the lower bushing of the needle bar.

[0004] Most modern sewing machines now include a left thread hook in the stitch path. This hook primarily stabilizes the left side of the top thread, preventing excessive swaying and resulting in poor stitch quality. Furthermore, due to the varying head shapes of different sewing machines, existing technologies often employ differently shaped left thread hooks to accommodate different machine heads and avoid the problem of excessive stitch transitions. Therefore, further structural improvements are needed to address the skipped stitches and thread breaks caused by the left thread hook. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a left thread hook assembly for sewing machines that can reduce thread breakage and skipped stitches, as well as a sewing machine using the left thread hook assembly.

[0006] The present invention adopts the following technical solution:

[0007] This utility model provides a left thread hook assembly for a sewing machine, including a fixing member and a left thread hook. The fixing member is fixed to the sewing machine head and located on the needle side of the take-up lever. An elastic reset member on the fixing member is connected to the left thread hook. The left thread hook is laterally movable on the fixing member towards the thread clamp side of the take-up lever. The left thread hook is provided with an upper guide part, a lower guide part, and an elastic part. Both the upper guide part and the lower guide part allow the top thread to pass through and guide the top thread towards the needle hole. The upper guide part and the lower guide part are flexibly connected from high to low, and the lower guide part can be reset under the action of the elastic part.

[0008] Preferably, the fixing component includes a fixing plate, an elastic reset component, and a slider. The fixing plate is fixed to the sewing machine head and located on the needle side of the take-up lever. The elastic reset component connects the fixing plate and the slider. The slider is laterally positioned on the fixing plate and can move laterally toward the thread clamp side of the take-up lever. The left thread hook is detachably mounted on the slider.

[0009] Preferably, the elastic reset element is a spring, with two springs arranged in parallel and spaced apart, and each spring having a fixed plate and a slider connected to its two ends respectively.

[0010] Preferably, the upper guide portion of the left hook is connected to a connecting portion, and both the slider and the connecting portion are made of magnetic material. The left hook is magnetically connected to the slider through the connecting portion.

[0011] Preferably, the upper guide portion and the lower guide portion are flexibly connected by an elastic portion.

[0012] Preferably, the upper guide portion and the lower guide portion are flexibly connected, and the elastic portion connects both the sewing machine head and the lower guide portion.

[0013] Preferably, the elastic part is a spring sheet.

[0014] This utility model also provides a sewing machine that uses the above-mentioned sewing machine left thread hook assembly.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] The left thread hook assembly of this invention can automatically adjust the thread tension between the upper and lower guide parts to the minimum tension angle when the thread demand increases and the top thread becomes taut. This is achieved by deflecting the lower guide part of the left thread hook away from the sewing machine head. Combined with the restoring effect of the elastic part, the deflection of the lower guide part only acts as a tension buffer for the top thread, preventing excessive thread supply and ensuring sewing quality. Conversely, when the thread demand is too high and the top thread tension exceeds the top thread's tolerance, the thread supply can be increased by laterally moving the left thread hook towards the take-up lever, thereby reducing the top thread tension. Thanks to the elastic restoring component, the thread supply will again not be excessive, ensuring sewing quality.

[0017] In summary, the left thread hook assembly of this invention can improve thread tension, thereby reducing sewing problems such as thread breakage and skipped stitches. At the same time, the left thread hook assembly of this invention can also dynamically adjust the amount of thread supplied to cope with different sewing conditions.

[0018] Since the sewing machine of this utility model adopts the above-mentioned left thread hook assembly, it naturally has the above-mentioned beneficial effects, which will not be elaborated here. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the left thread hook assembly of the sewing machine in an embodiment of this utility model.

[0020] Figure 2 This is a schematic diagram showing the installation state of the left thread hook assembly of the sewing machine in an embodiment of this utility model.

[0021] Figure 3 This is a schematic diagram of the structure of the fixing component on the left thread hook assembly of the sewing machine in an embodiment of this utility model.

[0022] Figure 4 This is a schematic diagram of the structure of the left hook on the left hook assembly of the sewing machine in an embodiment of this utility model.

[0023] The reference numerals in the attached figures are explained as follows:

[0024] 1. Fastener 203, Elastic part

[0025] 101. Elastic reset component; 204. Connecting part

[0026] 102. Fixing plate 3. Sewing machine head

[0027] 103. Slider 4. Thread take-up lever

[0028] 2. Left hook; 5. Machine needle

[0029] 201. Upper guide part 6. Wire clamp

[0030] 202. Lower guide section Detailed Implementation

[0031] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.

[0032] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0034] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0035] See Figure 1 and Figure 2 This embodiment provides a left thread hook assembly for a sewing machine, including a fixing member 1 and a left thread hook 2. The fixing member 1 is fixed on the sewing machine head 3 and located on the side of the needle 5 of the take-up lever 4. An elastic reset member 101 on the fixing member 1 is connected to the left thread hook 2. The left thread hook 2 is movably mounted on the fixing member 1 to the side of the thread clamp 6 of the take-up lever 4. The left thread hook 2 is provided with an upper guide part 201, a lower guide part 202 and an elastic part 203. Both the upper guide part 201 and the lower guide part 202 allow the top thread to pass through and guide the top thread towards the needle hole. The upper guide part 201 and the lower guide part 202 are flexibly connected from high to low, and the lower guide part 202 can be reset under the action of the elastic part 203.

[0036] See Figure 1 and Figure 2In this embodiment, the left thread hook assembly of the sewing machine can automatically adjust the thread tension between the upper guide 201 and the lower guide 202 to the minimum tension angle when the thread demand increases and the top thread becomes taut. This is achieved by deflecting the lower guide 202 of the left thread hook 2 away from the sewing machine head 3. In addition, the elastic part 203 provides a reset function, so the deflection of the lower guide 202 only serves as a tension buffer for the top thread and will not cause excessive thread supply, thus ensuring sewing quality. When the thread demand is too high and the thread tension exceeds the top thread's tolerance, the thread supply can be increased by moving the left thread hook 2 laterally towards the take-up lever 4, thereby reducing the top thread tension. Thanks to the elastic reset part 101, the thread supply will not be too high, ensuring sewing quality.

[0037] In summary, the left thread hook assembly of this embodiment can improve thread tension, thereby reducing sewing problems such as thread breakage and skipped stitches. At the same time, the left thread hook assembly of this embodiment can also dynamically adjust the amount of thread supplied through the left thread hook 2 to cope with different sewing conditions.

[0038] Preferably, see Figures 1 to 3 The fixing component 1 includes a fixing plate 102, an elastic reset component 101, and a slider 103. The fixing plate 102 is fixed on the sewing machine head 3 and located on the side of the needle 5 of the thread take-up lever 4. The elastic reset component 101 connects the fixing plate 102 and the slider 103. The slider 103 is limited on the fixing plate 102 so as to move laterally towards the thread clamp 6 of the thread take-up lever 4. The left thread hook 2 is detachably installed on the slider 103.

[0039] Preferably, the elastic reset element 101 is a spring, with two springs arranged in parallel and spaced apart, and each spring's two ends connected to the fixing plate 102 and the slider 103, respectively. The arrangement of the two springs ensures the elastic reset effect of the left hook 2 relative to the fixing element 1.

[0040] Preferably, see Figure 1 and Figure 4 The upper guide portion 201 of the left hook 2 is connected to the connecting portion 204. Both the slider 103 and the connecting portion 204 are made of magnetic material. The left hook 2 is magnetically connected to the slider 103 through the connecting portion 204.

[0041] It should be noted that the connection between the connecting part 204 of the left hook 2 and the upper slider 103 of the fixing part 1 can also be achieved by means of threaded connection, adhesive bonding, or other methods that facilitate disassembly and assembly.

[0042] Preferably, see Figure 1 and Figure 4 The upper guide portion 201 and the lower guide portion 202 are flexibly connected by the elastic portion 203.

[0043] In addition, in this embodiment, the upper guide portion 201 and the lower guide portion 202 can be flexibly connected, while the elastic portion 203 connects both the sewing machine head 3 and the lower guide portion 202. Specifically, one end of the elastic portion 203 can be fixed to the wall of the sewing machine head 3 by means of thread fixing, bonding, etc., while the other end of the elastic portion 203 is connected to the side of the lower guide portion 202 facing the sewing machine head 3.

[0044] Preferably, the elastic part 203 is a spring sheet, so that the lower guide part 202 in the deflected state can be reset by its own elastic recovery ability.

[0045] After applying the left thread hook assembly of this embodiment to a sewing machine, the following working conditions will occur, combined with... Figures 1 to 4 :

[0046] 1. For sewing thinner fabrics and other applications requiring less thread. In this case, the amount of top thread supplied should not be too much, the clamping force of the thread clamp 6 is small, the tension of the top thread is small, the left hook 2 is far from the take-up lever 4 and is in the initial working position on the fixing part 1, and the lower guide part 202 on the left hook 2 is also in the initial state without deflection.

[0047] 2. In situations where the amount of thread required increases, such as when sewing thinner fabrics is switched to thicker fabrics. In this situation, the top thread is taut and contacts the upper and lower guides of the left thread hook 2. Then, the take-up lever 4 moves the top thread, and the path of the top thread between the take-up lever 4 and the needle 5 changes as the thread moves. At this time, the shape of the elastic part 203 also changes with the change of the top thread path, so that the top thread between the upper guide 201 and the lower guide 202 automatically adapts to the angle of minimum tension.

[0048] 3. The working condition where the required amount of thread is too large, causing the tension of the thread to exceed the tolerance range of the thread. In this working condition, in addition to the shape of the elastic part 203 changing with the change of the thread path, the left hook 2 also drives the slider 103 on the fixing part 1 to move laterally towards the thread take-up lever 4, so as to increase the amount of thread supplied and reduce the tension of the thread.

[0049] IV. Situations where the amount of thread required decreases, such as when sewing thicker fabrics to thinner fabrics. In this situation, the elastic reset component 101 of the fixing component 1 drives the slider 103 to reset, thereby causing the left hook 2 to move laterally away from the take-up lever 4, thus reducing the amount of thread supplied to stabilize the tension of the top thread.

[0050] In addition, this embodiment also provides a sewing machine that uses the above-mentioned left thread hook assembly, which can improve thread tension by using the left thread hook assembly. After reducing thread tension, sewing problems such as thread breakage and skipped stitches can be reduced. At the same time, the left thread hook can also realize dynamic adjustment of the thread supply to cope with different sewing conditions.

[0051] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A left-hand hook assembly for a sewing machine, characterized in that, The device includes a fixing member (1) and a left thread hook (2). The fixing member (1) is fixed on the sewing machine head (3) and located on the side of the needle (5) of the take-up lever (4). The elastic reset member (101) on the fixing member (1) is connected to the left thread hook (2). The left thread hook (2) is movably disposed on the fixing member (1) towards the thread clamp (6) of the take-up lever (4). The left thread hook (2) is provided with an upper guide part (201), a lower guide part (202) and an elastic part (203). The upper guide part (201) and the lower guide part (202) are both for the top thread to pass through and guide the top thread towards the needle hole. The upper guide part (201) and the lower guide part (202) are flexibly connected from high to low, and the lower guide part (202) can be reset under the action of the elastic part (203).

2. The sewing machine left thread hook assembly according to claim 1, characterized in that, The fixing member (1) includes a fixing plate (102), an elastic reset member (101), and a slider (103). The fixing plate (102) is fixed on the sewing machine head (3) and located on the side of the needle (5) of the thread take-up lever (4). The elastic reset member (101) connects the fixing plate (102) and the slider (103). The slider (103) is laterally movable on the fixing plate (102) towards the thread clamp (6) of the thread take-up lever (4). The left thread hook (2) is detachably mounted on the slider (103).

3. The sewing machine left thread hook assembly according to claim 2, characterized in that, The elastic reset member (101) is a spring, and two springs are arranged in parallel and spaced apart. The two ends of each spring are respectively connected to the fixing plate (102) and the slider (103).

4. The sewing machine left thread hook assembly according to claim 2, characterized in that, The upper guide part (201) of the left hook (2) is connected to the connecting part (204). The slider (103) and the connecting part (204) are both made of magnetic material. The left hook (2) is magnetically connected to the slider (103) through the connecting part (204).

5. The sewing machine left thread hook assembly according to claim 1, characterized in that, The upper guide portion (201) and the lower guide portion (202) are flexibly connected by the elastic portion (203).

6. The sewing machine left thread hook assembly according to claim 1, characterized in that, The upper guide (201) is flexibly connected to the lower guide (202), and the elastic part (203) is connected to both the sewing machine head (3) and the lower guide (202).

7. The sewing machine left thread hook assembly according to claim 1, characterized in that, The elastic part (203) is a spring sheet.

8. A sewing machine, characterized in that, The sewing machine left-hand hook assembly according to any one of claims 1-7 is used.

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