Backstitch lift presser foot drive mechanism for a sewing machine

Abstract

The utility model relates to sewing machine technical field especially is a sewing machine needle lifting presser foot drive mechanism, including drive motor, the action of this drive motor is controlled by control box control, shaft handle drive part is connected with drive motor's output end transmission, chain drive part is connected with shaft handle drive part transmission, presser foot mechanism is connected with chain drive part's output, wherein drive drive chain drive part with chain drive part drive presser foot mechanism executes linear presser foot action, the utility model overcomes the defect that the system structure is complex, the volume is huge and the cost is high in prior art because of adopting multiple independent motor, utilizes single drive source to can control the stitch length adjustment, the backstitch and the presser foot function respectively, has simplified mechanical structure, has realized the miniaturization and light weight of equipment, has reduced manufacturing cost, and the power switching mode of pure machinery has eliminated the action impact, has guaranteed the stability of sewing process.

Description

Technical Field

[0001] This utility model relates to the field of sewing machine technology, specifically to a sewing machine needle reversing and presser foot lifting drive mechanism. Background Technology

[0002] As an important industrial and household appliance, the sewing machine's core functions, such as sewing, backstitching, and lifting the presser foot, rely on a precise and reliable internal drive transmission system.

[0003] In existing technologies, sewing machines typically use a separate dedicated motor for the stitch length adjustment, reverse stitching mechanism, and presser foot lifting mechanism. The advantage is that the control logic is simple and the functions do not interfere with each other. However, this increases the number of motors inside the sewing machine head, making the overall structure complex, bulky, and costly. Alternatively, a main motor can be used as the power source, transmitting power through complex linkages, cams, or gear systems. When a specific function needs to be performed, the corresponding electromagnet is energized to drive the clutch or shift fork mechanism, switching the power to the target execution component. Although this reduces the number of motors required, it results in a long transmission chain, complex mechanical structure, and problems such as high inertia, slow response, high noise, and easy wear of parts. Furthermore, the electromagnets generate impacts when they are engaged and disengaged, affecting the smoothness and accuracy of the sewing.

[0004] Therefore, a sewing machine needle reversal and presser foot drive mechanism is needed to improve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a sewing machine presser foot reversing mechanism to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A sewing machine presser foot reversing drive mechanism includes: The main body of the machine head and the drive motor, the operation of which is controlled by the control box; A shaft drive component is connected to the output end of the drive motor for transmission. The chain drive component is connected to the shaft drive component for transmission. The pressure foot lifting mechanism is connected to the output end of the chain drive component; The drive motor drives the chain transmission component to drive the presser foot lifting mechanism to perform a linear presser foot lifting action.

[0007] As a preferred embodiment of this utility model, the shaft drive component includes a shaft assembly, which includes a clutch mandrel and a clutch crank. The clutch mandrel is mounted on the motor shaft of the motor, and its end is provided with a protruding mandrel lever. The clutch crank is fixedly sleeved on the front end of the motor shaft, and its outer end is mated with the outer end of the mandrel lever of the clutch mandrel. The end face of the mandrel lever is provided with an arc-shaped notch ring edge, and one end extends outward to form a fan-shaped end face.

[0008] As a preferred embodiment of this utility model, the chain drive component includes a chain and a gear post; One end of the chain is connected to the shaft assembly, and the other end is connected to the end of the lifting foot mechanism; The gear column is rotatably mounted inside the machine head body and meshes with the middle side of the chain to change the transmission path and provide support.

[0009] As a preferred embodiment of the present invention, the shaft drive component further includes a crank, which is fixedly sleeved on the output shaft of the drive motor. The crank includes an arc end and a tip, and a backstitch control arc segment and a stitch length adjustment arc segment are provided between the arc end and the tip. The shaft drive is also configured to selectively transmit the power of the drive motor to the stitch length adjustment and reverse stitching mechanism; the reverse rotation of the drive motor drives the shaft drive to drive the stitch length adjustment and reverse stitching mechanism to perform stitch length adjustment or reverse stitching actions, and the forward rotation of the drive motor drives the chain drive to drive the presser foot lifting mechanism to perform linear presser foot lifting actions.

[0010] As a preferred embodiment of this utility model, the shaft drive component further includes a connecting rod structure; The connecting rod structure includes connecting rod a and connecting rod b that are hinged to each other, and connecting rod b has an abutting end that is configured to contact the contour of the crank. When the drive motor reverses, the stitch length adjustment arc segment and the backstitch control arc segment of the crank sequentially abut against the contact end of the connecting rod b, and the motion is transmitted to the stitch length adjustment and backstitch mechanism through the connecting rod structure.

[0011] As a preferred embodiment of this utility model, the radius of curvature of the stitch length adjustment arc segment is different from that of the backstitch control arc segment, so that the connecting rod structure generates different displacements when contacting different arc segments, thereby realizing differentiated control of stitch length adjustment and backstitch.

[0012] As a preferred embodiment of this utility model, one end of the connecting rod a is provided with a hook end; A return spring, the lower end of which is connected to the hook end and the upper end of which is connected to the inner wall of the machine head body, is used to provide a return force for the connecting rod structure.

[0013] Compared with the prior art, the beneficial effects of this utility model are: This invention overcomes the shortcomings of existing technologies, such as complex system structure, large size and high cost caused by the use of multiple independent motors. It can control the stitch length adjustment, reverse stitch and presser foot lifting functions separately with a single drive source, which simplifies the mechanical structure, realizes the miniaturization and weight reduction of the equipment, and reduces manufacturing costs. This invention avoids the drawbacks of traditional electromagnet clutch mechanisms. Its purely mechanical power switching method eliminates the impact of movement, ensures the smoothness of the sewing process, solves the problems of slow response and high noise, and improves the response speed, quiet operation, and long-term reliability of the transmission system. Attached Figure Description

[0014] Figure 1 This is an installation diagram of the present invention; Figure 2 This is a first-view perspective perspective view of the present invention; Figure 3 This is a second-view perspective perspective view of the present invention; Figure 4 This is a third-person perspective view of the present invention; Figure 5 This is a schematic diagram of the crank mechanism in this utility model; Figure 6 This utility model Figure 4 Enlarged view of point A in the middle.

[0015] In the diagram: 1. Main body of the machine head; 2. Drive motor; 3. Crank; 4. Spring; 5. Shaft assembly; 6. Gear column; 7. Chain; 8. Presser foot lifting mechanism; 9. Connecting rod a; 10. Mounting rod; 11. Hook end; 12. Connecting rod b; 13. Stitch length adjustment arc segment; 14. Backstitch control arc segment; 15. Clutch mandrel; 16. Clutch crank; 17. Mandrel lever; 18. Arc-shaped notch ring edge; 19. Fan-shaped end face. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0017] To facilitate understanding of this utility model, a more comprehensive description of it will be provided below with reference to relevant embodiments. Several embodiments of this utility model are given. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0018] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] Please see Figure 1-6 This utility model provides a technical solution: For an example, please refer to... Figure 1 , 2 3, 4, 5 and 6, a sewing machine presser foot lifting drive mechanism, including a machine head body 1, a drive motor 2, a shaft drive component, a chain drive component and a presser foot lifting mechanism 8. The machine head body 1 has an installation space for installing the various components. The drive motor 2 is fixedly installed in this installation space and serves as the sole power source for the entire transmission system. The drive motor 2 is preferably a programmable servo motor so as to precisely control its rotation angle and direction.

[0021] Please refer to Figure 1 , 2 3, 4, 5 and 6, the shaft drive unit includes shaft assembly 5, crank 3 and a set of connecting rod structure. One end of shaft assembly 5 is directly connected to the output end of drive motor 2 to obtain power. The shaft drive unit is connected to the output end of drive motor 2 for transmission.

[0022] In a preferred embodiment, the shaft drive includes a shaft assembly 5, which includes a clutch mandrel 15 and a clutch crank 16. The clutch mandrel 15 is disposed on the motor shaft of the motor, and its end is provided with a protruding mandrel lever 17. The clutch crank 16 is fixedly sleeved on the front end of the motor shaft, and its outer end is mated with the outer end of the mandrel lever 17 of the clutch mandrel 15. The end face of the mandrel lever 17 is provided with an arc-shaped notch ring edge 18, and one end of its side extends outward to form a fan-shaped end face 19. The crank 3 is fixedly mounted on the output shaft of the drive motor 2 and rotates together with the shaft. The crank 3 includes a tip and a stitch pitch adjustment arc segment 13 and a backstitch control arc segment 14 extending from the tip to one side. The curvature radii of these two arc segments are designed to be different to achieve differentiated control.

[0023] Please refer to Figure 1 , 2 3 and 4, the linkage structure includes connecting rod a9 and connecting rod b12 that are hinged to each other. The lower end of connecting rod b12 forms an abutment end. One end of connecting rod a9 is provided with a hook end 11. The lower end of the return spring 4 is hooked on this hook end 11, and its upper end is hooked on the inner wall of the machine head body 1.

[0024] The chain drive is used to transmit power to the presser foot lifting mechanism 8. It includes a chain 7 and a gear 6. One end of the chain 7 is connected to the shaft assembly 5, and the other end is connected to the movable end of the presser foot lifting mechanism 8. The gear 6 is rotatably mounted inside the machine head body 1, and its position allows it to mesh with the middle side of the chain 7.

[0025] Working principle: When the presser foot lifting action needs to be performed, the control system drives the drive motor 2 to rotate forward. When the drive motor 2 rotates forward, it drives the shaft assembly 5 to rotate accordingly. The rotation of the shaft assembly 5 will wind the chain 7. The chain 7 passes around the gear column 6, thereby pulling the end of the presser foot lifting mechanism 8, so that it performs a linear and continuous action to lift the presser foot. During this process, the crank 3 sleeved on the shaft assembly 5 rotates with the shaft, but its outline does not abut against the upper end of the connecting rod b12 below, so it will not trigger the stitch length adjustment or reverse sewing action.

[0026] When stitch length adjustment or reverse stitching is required, the control system drives the drive motor 2 to reverse. When the drive motor 2 reverses, it also drives the shaft assembly 5 and crank 3 to reverse. During the reverse process, the stitch length adjustment arc segment 13 and the reverse stitching control arc segment 14 on the crank 3 will successively abut against the upper end of the connecting rod b 12.

[0027] In the initial reversal phase, the stitch length adjustment arc segment 13 of crank 3 first makes contact. Due to the specific curvature of this arc segment, it pushes the connecting rod b12, and then transmits a specific amplitude and direction of motion to the stitch length adjustment and reverse sewing mechanism through the entire connecting rod structure, thereby realizing the adjustment of the stitch length.

[0028] The drive motor 2 continues to reverse, and the backstitch control arc segment 14 of the crank 3 then contacts the upper end of the connecting rod b12. Since the radius of curvature of this segment is different from that of the stitch length adjustment arc segment 13, it will drive the connecting rod structure to produce another different displacement, thereby triggering the backstitch function in the stitch length adjustment and backstitch mechanism to achieve reinforced sewing.

[0029] After the action is completed, the drive motor 2 stops or reverses to reset. Under the pulling force of the reset spring 4, the connecting rod structure composed of connecting rod a9 and connecting rod b12 is pulled back to the initial position, so that the abutting end of connecting rod b12 maintains stable contact with the contour of crank 3 again, preparing for the next action.

[0030] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A sewing machine backtack lift presser foot drive mechanism for a sewing machine, comprising: include: The machine head body (1) and the drive motor (2) are controlled by the control box; The shaft drive component is connected to the output end of the drive motor (2) for transmission. The chain drive component is connected to the shaft drive component for transmission. The foot lifting mechanism (8) is connected to the output end of the chain drive component; The drive motor (2) drives the chain transmission component to drive the presser foot lifting mechanism (8) to perform a linear presser foot lifting action.

2. The sewing machine needle reversing and presser foot lifting drive mechanism according to claim 1, characterized in that: The shaft drive component includes a shaft assembly (5), which includes a clutch mandrel (15) and a clutch crank (16). The clutch mandrel (15) is mounted on the motor shaft of the motor and has a protruding mandrel lever (17) at its end. The clutch crank (16) is fixedly sleeved on the front end of the motor shaft and its outer end is mated with the outer end of the mandrel lever (17) of the clutch mandrel (15). The end face of the mandrel lever (17) has an arc-shaped notch ring edge (18) and one end extends outward to form a fan-shaped end face (19).

3. The sewing machine needle reversing and presser foot lifting drive mechanism according to claim 2, characterized in that: The chain drive component includes a chain (7) and a gear column (6); One end of the chain (7) is connected to the shaft assembly (5), and the other end is connected to the end of the lifting foot mechanism (8); The gear column (6) is rotatably mounted inside the head body (1) and meshes with the middle side of the chain (7) to change the transmission path and provide support.

4. The sewing machine needle reversing and presser foot lifting drive mechanism according to any one of claims 1-3, characterized in that: The shaft drive component also includes a crank (3), which is fixedly sleeved on the output shaft of the drive motor (2). The crank (3) includes an arc end and a tip, and a backstitch control arc segment (14) and a stitch length adjustment arc segment (13) are provided between the arc end and the tip. The shaft drive is also configured to selectively transmit the power of the drive motor (2) to the stitch length adjustment and backstitching mechanism; the reverse rotation of the drive motor (2) drives the shaft drive to drive the stitch length adjustment and backstitching mechanism to perform stitch length adjustment or backstitching actions, and the forward rotation of the drive motor (2) drives the chain drive to drive the presser foot lifting mechanism (8) to perform linear presser foot lifting actions.

5. The sewing machine needle reversing and presser foot lifting drive mechanism according to claim 4, characterized in that: The shaft drive component also includes a connecting rod structure; The connecting rod structure includes connecting rod a (9) and connecting rod b (12) that are hinged to each other, the connecting rod b (12) having an abutting end that is configured to contact the contour of the crank (3); When the drive motor (2) reverses, the stitch length adjustment arc segment (13) and the backstitch control arc segment (14) of the crank (3) abut against the contact end of the connecting rod b (12) in sequence, and transmit the motion to the stitch length adjustment and backstitch mechanism through the connecting rod structure.

6. The sewing machine reverse needle presser foot lifting drive mechanism according to claim 5, wherein: The radius of curvature of the stitch length adjustment arc segment (13) is different from that of the backstitch control arc segment (14), so that the connecting rod structure generates different displacements when it contacts different arc segments, thereby realizing differentiated control of stitch length adjustment and backstitch.

7. The sewing machine needle reversing and presser foot lifting drive mechanism according to claim 5, characterized in that: One end of the connecting rod a (9) is provided with a hook end (11). The lower end of the return spring (4) is connected to the hook end (11), and the upper end is connected to the inner wall of the machine head body (1), which is used to provide a return force for the connecting rod structure.

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