Sewing machine cutting device and sewing machine

Abstract

The utility model discloses a sewing machine shearing device and sewing machine belong to sewing machine technical field. It includes: knife seat subassembly, movable tool rest and movable blade, movable blade sets up in movable tool rest, movable tool rest is stacked with knife seat subassembly upside down and is detachably connected through first fastener, and first fastener allows movable tool rest to rotate around its own plane in the state of not locking, drives movable blade to rotate to adjust the shearing angle between it and external fixed blade, adjusting bolt, one end is connected with knife seat subassembly thread, and the other end forms axial limit cooperation with movable tool rest, drives movable tool rest to carry out trace rotation around the axis of first fastener through rotating adjusting bolt, realizes the fine adjustment of shearing angle. This design allows under the condition of not disassembling or repositioning knife seat subassembly, directly through the rotation adjusting bolt to adjust the shearing angle fast, not only reduces the adjustment time, and can adjust the shearing angle more accurately.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology, specifically relating to a sewing machine cutting device and a sewing machine. Background Technology

[0002] In existing sewing machine shearing devices, the adjustment of the shearing angle between the movable blade and the fixed blade typically relies on adjusting the overall position of the blade holder assembly. In traditional structures, the blade holder and the blade assembly are integrally connected or rigidly fixed, preventing relative rotation between them. When adjusting the shearing angle, the operator must manually loosen the connection between the blade holder and the machine body, rotate the entire blade holder assembly to rotate the movable blade, and then re-lock it securely.

[0003] This type of adjustment method has significant drawbacks:

[0004] 1. Insufficient adjustment precision: Since there is no independent degree of rotation between the tool holder and the tool post, the entire tool holder assembly must be moved synchronously when adjusting the shearing angle, resulting in an excessively long adjustment lever arm and amplified operation error, making it difficult to achieve fine adjustment of the shearing angle;

[0005] 2. Low operating efficiency: Each adjustment requires repeatedly tightening and loosening the tool holder fixing parts, which is time-consuming and can easily cause the tool holder to shift in position, affecting the shearing stability. Summary of the Invention

[0006] This invention addresses the aforementioned problems in the existing technology by proposing a sewing machine shearing device and a sewing machine that facilitates adjustment of the shearing angle and improves adjustment accuracy.

[0007] This utility model can be achieved through the following technical solutions:

[0008] A sewing machine cutting device, comprising:

[0009] The tool holder assembly, the movable tool holder, and the movable blade are provided. The movable blade is disposed on the movable tool holder. The movable tool holder and the tool holder assembly are stacked on top of each other and are detachably connected by a first fastener. The movement of the tool holder assembly drives the movable tool holder and the movable blade to move synchronously and perform a cutting action.

[0010] The first fastener, when not locked, allows the movable blade holder to rotate around its own plane, causing the movable blade to rotate to adjust the shearing angle between it and the external fixed blade;

[0011] The adjusting bolt has one end threadedly connected to the tool holder assembly and the other end forming an axial limiting fit with the movable tool holder. By rotating the adjusting bolt, the movable tool holder is driven to rotate slightly around the axis of the first fastener, thereby achieving fine adjustment of the shearing angle.

[0012] As a further improvement of this utility model, the tool holder assembly includes a movable tool holder and a movable tool shaft, the movable tool shaft being connected to the movable tool holder, and the movable tool post being connected to the movable tool shaft.

[0013] As a further improvement of this utility model, a limiting groove is provided on one side of the top surface of the movable tool holder, the adjusting bolt is threadedly connected to the movable tool shaft, and the adjusting bolt has a mating block embedded in the limiting groove. When the adjusting bolt is rotated, the adjusting bolt moves axially relative to the movable tool shaft, and the movable tool holder is driven to rotate around the first fastener through the mating block.

[0014] As a further improvement of this utility model, the movable tool holder has a waist hole, the first fastener passes through the waist hole and is threadedly connected to the movable tool shaft. When the first fastener is not in the locked state, the contact surface between the movable tool holder and the movable tool shaft is separated, the movable tool holder can rotate around the axis of the first fastener, and the movable tool holder can also move left and right along the length direction of the waist hole.

[0015] As a further improvement of this utility model, the movable blade is detachably connected to the movable blade holder by a second fastener, and one end of the shearing surface of the movable blade is provided with a downwardly protruding guide portion, the guide portion having an inclined guide slope.

[0016] As a further improvement of this utility model, the movable tool holder and the movable tool shaft are connected by a pressure adjusting screw, and the pressure adjusting screw is provided with a compression spring. The compression spring always provides a thrust to the movable tool shaft away from the movable tool holder.

[0017] As a further improvement of this utility model, the pressure adjusting screw passes through the movable tool holder and the movable tool shaft, and adjusting nuts are screwed on both ends of the pressure adjusting screw. By rotating the adjusting nuts, the compression amount of the compression spring is adjusted and the elastic force applied between the movable tool holder and the movable tool shaft is changed.

[0018] A sewing machine is also provided, having the above-mentioned sewing machine cutting device, further comprising: a sewing machine main frame and a drive shaft, wherein the drive shaft is vertically mounted on the sewing machine main frame, and the end of the drive shaft is connected to the movable cutter holder, and the drive shaft is driven to move axially by a drive unit to drive the movable cutter holder to move up and down.

[0019] As a further improvement of this utility model, the movable tool holder has a locking part, and the drive shaft is inserted into the locking part and locked in place. The end of the drive shaft inserted into the locking part has a positioning groove that is opened along the axial direction on its surface. At the same time, the locking part has a positioning hole, and a positioning screw is inserted into the positioning hole. The end of the positioning screw is embedded in the positioning groove.

[0020] As a further improvement of this utility model, the upper end of the positioning groove is provided with a locking surface, the shape of which is adapted to the end shape of the positioning screw. When the drive shaft is inserted into the locking part until the locking surface abuts against the positioning screw, the drive shaft and the positioning screw form a limiting fit.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. Improved adjustment efficiency: Allows for quick adjustment of the shearing angle by rotating the adjusting bolt directly without disassembling or repositioning the cutter holder assembly. Compared to the traditional method that requires repeated tightening and loosening of the cutter holder fixing parts, this method is simpler and faster, saving adjustment time and reducing positional deviation caused by improper installation.

[0023] 2. Improved adjustment accuracy: By setting an independent shearing angle adjustment mechanism (adjusting bolt), a fine adjustment of the shearing angle between the moving blade and the fixed blade is achieved. This avoids the large errors caused by the overall moving blade holder assembly in the traditional method, and can control the shearing angle more accurately.

[0024] 3. Ensure cutting quality: By providing a fine adjustment function for the cutting angle, the cutting angle between the movable blade and the fixed blade can be precisely set according to actual needs. At the same time, the pressure adjustment screw used to connect the movable blade holder and the movable blade shaft is equipped with a compression spring. As the movable blade continues to move down to complete the cutting action, relative sliding occurs between the guide slope and the fixed blade. Meanwhile, the compression spring continuously applies a pushing force, ensuring that the movable blade always maintains a good fit with the cutting surface of the fixed blade. This design effectively improves the stability and consistency of the cutting process and avoids problems such as uneven cutting and fabric pulling caused by changes in gap or angle deviation.

[0025] 4. Simplified maintenance and use: Compared with the traditional complicated adjustment methods, this utility model provides a more intuitive and easy-to-operate adjustment mechanism, which reduces the user's learning cost and operation difficulty, and also simplifies daily maintenance work, which helps to extend the service life of the equipment.

[0026] 5. Easy maintenance: The locking part of the movable blade holder, which is used to connect with the sewing machine drive shaft, is equipped with a positioning screw. The positioning screw cooperates with the locking surface of the positioning groove on the drive shaft surface, so that the relative position between the drive shaft and the movable blade holder remains unchanged after reassembly. Therefore, the shearing angle and other parameters between the movable blade and the fixed blade do not need to be readjusted, and can be directly restored to the state before disassembly. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the shearing device of this utility model;

[0028] Figure 2 This is the utility model Figure 1 A structural diagram from another perspective;

[0029] Figure 3 This is the utility model Figure 1 A schematic diagram of the internal structure after removing the movable cutter shaft;

[0030] Figure 4 This is an exploded view of the shearing device of this utility model;

[0031] Figure 5 This is a schematic diagram of the structure of the shearing device of this utility model installed behind the main frame of the sewing machine;

[0032] Figure 6 This is the utility model Figure 5 A structural diagram from another perspective;

[0033] Figure 7 This is a partial cross-sectional view of the mating point between the positioning screw and the positioning groove on the drive shaft surface of this utility model.

[0034] In the diagram, 100 is the tool holder assembly; 110 is the movable tool holder; 111 is the locking part; 1111 is the positioning screw; 120 is the movable tool shaft; 121 is the adjusting bolt; 1211 is the mating block; 130 is the pressure adjusting screw; 131 is the compression spring; and 132 is the adjusting nut.

[0035] 200. Movable tool holder; 210. First fastener; 211. Waist hole; 220. Limiting groove;

[0036] 300. Movable blade; 310. Guide section;

[0037] 400. Fixed blade;

[0038] 500. Sewing machine main frame; 510. Drive shaft; 511. Positioning groove; 5111. Locking surface. Detailed Implementation

[0039] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. The technical methods of the present invention will be further described, but the present invention is not limited to these embodiments.

[0040] like Figures 1-7 As shown, this utility model provides a sewing machine cutting device, comprising:

[0041] The tool holder assembly 100, the movable tool holder 200, and the movable blade 300 are provided. The movable blade 300 is located at the front end of the movable tool holder 200. The movable tool holder 200 and the tool holder assembly 100 are stacked vertically and detachably connected by the first fastener 210. The movement of the tool holder assembly 100 drives the movable tool holder 200 and the movable blade 300 to move synchronously and perform a cutting action.

[0042] When the first fastener 210 is not locked, the movable blade holder 200 is allowed to rotate around the axis of the first fastener 210, thereby driving the movable blade 300 to rotate relative to the external fixed blade 400, so as to adjust the shearing angle between the two. This shearing angle directly affects the sharpness and stability during the shearing process and is one of the key parameters affecting the shearing quality.

[0043] To achieve precise adjustment of the shearing angle, an adjusting bolt 121 is further provided. One end of the adjusting bolt 121 is threadedly connected to the tool holder assembly 100, and the other end forms an axial limiting fit with the movable tool holder 200. Specifically, when the adjusting bolt 121 is rotated, it can move axially in the tool holder assembly 100 and push or pull the movable tool holder 200 through the limiting structure, so that the movable tool holder 200 rotates slightly around the axis of the first fastener 210, thereby achieving fine adjustment of the shearing angle.

[0044] It should be noted that in existing sewing machine shearing devices, because the blade holder and blade base are rigidly connected and fixed, they cannot rotate relative to each other. As a result, the adjustment of the shearing angle between the movable blade 300 and the fixed blade 400 usually depends on the overall position adjustment of the blade base assembly 100. This adjustment method has two problems. First, the operation error is amplified due to the excessively long adjustment lever arm, making it difficult to achieve fine adjustment of the shearing angle. Second, each adjustment requires repeated tightening and loosening of the blade base fixing parts, which is time-consuming and can easily cause the blade base installation position to shift, affecting the shearing stability.

[0045] In contrast, this application, by setting the movable tool holder 200 and the tool support assembly 100 as separate structures, and by adding the adjusting bolt 121, allows the movable tool holder 200 to rotate independently. This improvement has at least the following advantages:

[0046] 1. Improved adjustment efficiency: The shearing angle can be quickly adjusted by rotating the adjusting bolt 121 without disassembling or repositioning the cutter holder assembly 100. Compared with the traditional method that requires repeated tightening and loosening of the cutter holder fixing parts, this method is simpler and faster, saves adjustment time and reduces positional deviation caused by improper installation.

[0047] 2. Improved adjustment accuracy: By setting an independent shearing angle adjustment mechanism (adjusting bolt 121), a small-scale fine adjustment of the shearing angle between the movable blade 300 and the fixed blade 400 is achieved. This avoids the large error caused by the overall moving blade holder assembly 100 in the traditional method, and can control the shearing angle more accurately.

[0048] 3. Ensure cutting quality: By providing a fine adjustment function for the cutting angle, the cutting angle between the movable blade 300 and the fixed blade 400 can be precisely set according to actual needs, thereby effectively improving the cutting sharpness and stability, significantly improving the cutting quality, and meeting the requirements of high-precision sewing processes.

[0049] 4. Simplified maintenance and use: Compared with the traditional complicated adjustment methods, this utility model provides a more intuitive and easy-to-operate adjustment mechanism, which reduces the user's learning cost and operation difficulty, and also simplifies daily maintenance work, which helps to extend the service life of the equipment.

[0050] Overall, the sewing machine shearing device provided in this embodiment first improves the adjustment efficiency of the 300° shearing angle of the movable blade, and at the same time, it can further improve the adjustment accuracy, thereby ensuring shearing stability and shearing accuracy, and ultimately improving the quality of the finished product. It is particularly suitable for high-end sewing process scenarios.

[0051] Preferably, the blade holder assembly 100 includes a movable blade holder 110 and a movable blade shaft 120. The movable blade shaft 120 and the movable blade holder 110 are connected to form the support base of the shearing device. The movable blade holder 200 is located at the bottom of the movable blade shaft 120 and is detachably connected to the movable blade shaft 120 by a first fastener 210.

[0052] This structural design allows relative rotation between the movable tool holder 200 and the movable tool shaft 120 in an unlocked state, thereby driving the movable blade 300 to rotate around the axis of the first fastener 210, thus achieving adjustment of the shearing angle. The movable tool shaft 120, as an intermediate connecting component, not only ensures a stable transmission relationship between the movable tool holder 200 and the movable tool support 110, but also provides an independent degree of freedom for adjusting the shearing angle, avoiding the inconvenience and precision loss caused by the need to move the entire tool support assembly 100 in traditional structures.

[0053] Furthermore, a limiting groove 220 is provided on one side of the top surface of the movable tool holder 200, and the adjusting bolt 121 is threadedly connected to the movable tool shaft 120. The adjusting bolt 121 has a mating block 1211 that is embedded in the limiting groove 220. Specifically:

[0054] When the adjusting bolt 121 is rotated, the adjusting bolt 121 moves axially relative to the movable cutter shaft 120, and the mating block 1211 slides or pushes in the limiting groove 220, causing the movable cutter post 200 to rotate slightly around the first fastener 210.

[0055] This design allows operators to make precise adjustments to the shearing angle with a simple rotation, without having to move the entire blade assembly 100, which significantly improves adjustment accuracy and ease of operation.

[0056] Preferably, the movable tool holder 200 has a slotted hole 211, through which the first fastener 210 passes and is threadedly connected to the movable tool shaft 120.

[0057] In the unlocked state, the movable tool holder 200 can generate a certain degree of deflection freedom relative to the movable tool shaft 120 within the waist hole 211, thereby realizing a small rotation around the axis of the first fastener 210;

[0058] In addition, the movable blade holder 200 can also move left and right along the length of the waist hole 211, thereby adjusting the position of the movable blade 300 so that the movable blade 300 and the fixed blade 400 can be aligned left and right.

[0059] In the locked state, the movable blade holder 200 is firmly fixed, maintaining the set shearing angle. This design ensures both the flexibility of the movable blade holder 200 during adjustment and the stability of the final shearing angle.

[0060] Preferably, the movable blade 300 is detachably connected to the movable blade holder 200 by a second fastener. One side of the cutting surface of the movable blade 300 is provided with a downwardly protruding guide portion 310. The guide portion 310 has an inclined guide slope. At the beginning of the shearing stage, the guide slope will contact the shearing surface of the fixed blade 400 first, so as to play a guiding role.

[0061] To further ensure the shearing quality of the movable blade 300 during the downward shearing process, a compression spring 131 is provided on the pressure adjusting screw 130 between the movable blade holder 110 and the movable blade shaft 120. The compression spring 131 always provides the movable blade shaft 120 with a thrust away from the movable blade holder 110, that is, always provides the axial shearing pressure of the movable blade 300.

[0062] Specifically, as the movable blade 300 continues to move downward to complete the cutting action, relative sliding occurs between the guide slope and the fixed blade 400. At the same time, the compression spring 131 continuously applies a pushing force, ensuring that the movable blade 300 always maintains good contact with the cutting surface of the fixed blade 400. This design effectively improves the smoothness and consistency of the cutting process, avoiding problems such as uneven cutting and fabric pulling caused by changes in gap or angle deviation.

[0063] In addition, the pressure adjusting screw 130 passes through the movable tool holder 110 and the movable tool shaft 120, and adjusting nuts 132 are screwed on both ends of it. By rotating the adjusting nuts 132, the compression amount of the compression spring 131 can be adjusted, thereby changing the elastic force applied between the movable tool holder 110 and the movable tool shaft 120.

[0064] When the compression increases, the thrust of the compression spring 131 increases, and the preload between the movable cutter holder 110 and the movable cutter shaft 120 is enhanced; conversely, when the compression decreases, the preload decreases accordingly. This structural design enables stepless adjustable control of the internal pressure of the shearing device.

[0065] It should be noted that since the movable blade 300 is fixed on the movable blade holder 200, and the movable blade holder 200 is connected to the movable blade shaft 120, the pressure change between the movable blade holder 110 and the movable blade shaft 120 will eventually be fed back to the contact state between the movable blade 300 and the fixed blade 400. By adjusting the compression amount of the compression spring 131, the contact pressure between the movable blade 300 and the fixed blade 400 can be indirectly controlled, ensuring stable and efficient shearing operation under different working conditions.

[0066] like Figures 4-6 As shown, this utility model also improves a sewing machine having the above-mentioned sewing machine cutting device, and further includes: a sewing machine main frame 500 and a drive shaft 510. The drive shaft 510 is vertically arranged on the sewing machine main frame 500. The end of the drive shaft 510 is connected to the movable blade holder 110. The drive shaft 510 is driven to move axially through the drive unit to drive the movable blade holder 110 to move up and down, thereby driving the movable blade 300 to move up and down. In this process, the cutting surfaces of the movable blade 300 and the fixed blade 400 can achieve the cutting of the fabric.

[0067] Preferably, the movable tool holder 110 has a locking part 111, and the drive shaft 510 is inserted into the locking part 111 and locked in place. Specifically:

[0068] The drive shaft 510 is inserted into one end of the locking part 111, and its surface is provided with a positioning groove 511 that is opened along the axial direction;

[0069] The locking part 111 is provided with a positioning hole, and a positioning screw 1111 is inserted into the positioning hole;

[0070] The end of the positioning screw 1111 is embedded in the positioning groove 511 on the drive shaft 510, thereby preventing the drive shaft 510 from rotating and sliding in the locking part 111, and ensuring the stability and reliability of power transmission.

[0071] To further enhance the stability of the connection, a locking surface 5111 is provided at the upper end of the positioning groove 511. The shape of the locking surface 5111 is adapted to the end shape of the positioning screw 1111.

[0072] When the drive shaft 510 is fully inserted into the locking part 111 and reaches the predetermined position, the locking surface 5111 is in close contact with the end of the positioning screw 1111, forming a limiting fit to ensure that the drive shaft 510 will not undergo axial displacement or rotation, thus ensuring the precise execution of the shearing action.

[0073] It is also worth mentioning that during routine maintenance, the shearing device needs to be disassembled. However, due to the matching design of the positioning screw 1111 and the locking surface 5111 of the positioning groove 511, the relative position between the drive shaft 510 and the movable blade holder 110 remains unchanged after reassembly. Therefore, the shearing angle and other parameters between the movable blade 300 and the fixed blade 400 do not need to be adjusted again and can be directly restored to the state before disassembly.

[0074] The technical means disclosed in this utility model are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above are specific embodiments of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

[0075] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0076] Furthermore, in this utility model, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0077] The technical solutions of the various embodiments of this utility model can be combined with each other, but only if they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

[0078] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A sewing machine cutting device, characterized in that, include: The tool holder assembly, the movable tool holder, and the movable blade are provided. The movable blade is disposed on the movable tool holder. The movable tool holder and the tool holder assembly are stacked on top of each other and are detachably connected by a first fastener. The movement of the tool holder assembly drives the movable tool holder and the movable blade to move synchronously and perform a cutting action. The first fastener, when not locked, allows the movable blade holder to rotate around its own plane, causing the movable blade to rotate to adjust the shearing angle between it and the external fixed blade; The adjusting bolt has one end threadedly connected to the tool holder assembly and the other end forming an axial limiting fit with the movable tool holder. By rotating the adjusting bolt, the movable tool holder is driven to rotate slightly around the axis of the first fastener, thereby achieving fine adjustment of the shearing angle.

2. The sewing machine cutting device according to claim 1, characterized in that, The tool holder assembly includes a movable tool holder and a movable tool shaft, the movable tool shaft being connected to the movable tool holder, and the movable tool post being connected to the movable tool shaft.

3. A sewing machine cutting device according to claim 2, characterized in that, A limiting groove is provided on one side of the top surface of the movable tool holder. The adjusting bolt is threadedly connected to the movable tool shaft, and the adjusting bolt has a mating block embedded in the limiting groove. When the adjusting bolt is rotated, the adjusting bolt moves axially relative to the movable tool shaft, and the mating block drives the movable tool holder to rotate around the first fastener.

4. A sewing machine cutting device according to claim 2, characterized in that, The movable tool holder has a waist hole, and the first fastener passes through the waist hole and is threadedly connected to the movable tool shaft. When the first fastener is not in the locked state, the contact surface between the movable tool holder and the movable tool shaft is separated, the movable tool holder can rotate around the axis of the first fastener, and the movable tool holder can also move left and right along the length direction of the waist hole.

5. A sewing machine cutting device according to claim 1, characterized in that, The movable blade is detachably connected to the movable blade holder via a second fastener. One side of the shearing surface of the movable blade is provided with a downwardly protruding guide portion, and the guide portion has an inclined guide slope.

6. A sewing machine cutting device according to claim 2, characterized in that, The movable tool holder and the movable tool shaft are connected by a pressure adjusting screw. The pressure adjusting screw is equipped with a compression spring, which always provides a thrust to the movable tool shaft away from the movable tool holder.

7. A sewing machine cutting device according to claim 6, characterized in that, The pressure adjusting screw passes through the movable tool holder and the movable tool shaft, and adjusting nuts are screwed on both ends of the pressure adjusting screw. By rotating the adjusting nuts, the compression amount of the compression spring is adjusted and the elastic force applied between the movable tool holder and the movable tool shaft is changed.

8. A sewing machine comprising a sewing machine cutting device as described in any one of claims 1-7, characterized in that, It also includes a sewing machine main frame and a drive shaft. The drive shaft is vertically mounted on the sewing machine main frame, and the end of the drive shaft is connected to the movable cutter holder. The drive shaft is driven to move axially by a drive unit to drive the movable cutter holder to move up and down.

9. A sewing machine according to claim 8, characterized in that, The movable tool holder has a locking part, and the drive shaft is inserted into the locking part and locked in place. One end of the drive shaft inserted into the locking part has a positioning groove that is opened along the axial direction on its surface. At the same time, the locking part has a positioning hole, and a positioning screw is inserted into the positioning hole. The end of the positioning screw is embedded in the positioning groove.

10. A sewing machine according to claim 9, characterized in that, The upper end of the positioning groove is provided with a locking surface, the shape of which is adapted to the end shape of the positioning screw. When the drive shaft is inserted into the locking part until the locking surface abuts against the positioning screw, the drive shaft and the positioning screw form a limiting fit.

Images