One-driving-two mechanism of lockstitch sewing machine

Abstract

The utility model belongs to the technical field of lockstitch sewing machines, and particularly relates to a one-to-two mechanism of a lockstitch sewing machine, which comprises a machine body, a stitch length swing seat and a presser foot lifting upper lever are respectively and rotatably arranged in the machine body, a stepping motor is mounted on the side surface of the machine body, a main shaft is arranged in the stepping motor, and a stitch length adjusting cam and a presser foot lifting cam are respectively mounted on the main shaft; a stitch length connecting rod is arranged on one side of the stitch length adjusting cam, a first driving part for pushing the stitch length adjusting cam is formed on the stitch length connecting rod, one end of the stitch length connecting rod is hinged to the machine body, a swing seat connecting rod is hinged to the other end of the stitch length connecting rod, and the other end of the swing seat connecting rod is hinged to the stitch length swing seat; by means of the design of the two cams, the presser foot lifting mechanism can respectively drive the presser foot lifting mechanism to act or control the needle pitch, the effect of one-to-two is achieved, the structure of parts is simple, and the machining cost is low.

Description

Technical Field

[0001] This utility model relates to the field of flat sewing machine technology, and specifically to a one-to-two mechanism for a flat sewing machine. Background Technology

[0002] Existing sewing machines propose a technical solution that uses a stepper motor to control the stitch length adjustment and presser foot lifting action. Mechanical transmission components such as a stitch length adjustment crank and a presser foot lifting crank are installed on the motor. The stitch length adjustment crank indirectly or directly acts on the swing seat, adjusting the angle and position of action of the stepper motor and the stitch length adjustment crank to achieve the adjustment of the sewing machine's stitch length. Then, the stepper motor is used to lift the presser foot at different rotation angles, achieving the technical effect of one stepper motor driving two functions.

[0003] For example, Chinese Utility Model Patent No. CN202120296647.9 discloses a presser foot lifting mechanism for a sewing machine, which has a presser foot lifting cam and a presser foot lifting rod. The presser foot lifting mechanism also has a rotating lever, a drive motor, and a stitch position positioning wheel. The presser foot lifting rod abuts against the highest point of the presser foot driven by the drive motor on the presser foot lifting cam. The sliding element of the rotating lever is located in the middle of the stitch position positioning groove of the stitch position positioning wheel. The presser foot lifting mechanism performs the presser foot lifting action when the feed dog stops its forward and backward feeding action.

[0004] The combination wheel enables the sewing machine to perform actions such as adjusting the stitch length, positioning the feed dog to stop feeding the fabric before and after, raising the presser foot, and cutting the thread at different time periods. The structure of this combination wheel is relatively complex, requires high processing precision, and is costly. Therefore, its structure needs further improvement. Utility Model Content

[0005] The purpose of this invention is to provide a one-to-two mechanism for a flat sewing machine, which uses two cams to achieve the functions of raising the presser foot and adjusting the stitch length, thus solving the problem of the complexity of existing mechanisms.

[0006] The purpose of this utility model is achieved as follows: a one-to-two mechanism for a flat sewing machine includes a machine body, in which a stitch pitch swing seat and a lever for lifting the presser foot are rotatably arranged respectively. A stepper motor is installed on the side of the machine body, and a main shaft is arranged inside the stepper motor. A stitch pitch adjustment cam and a presser foot lifting cam are respectively installed on the main shaft.

[0007] A stitch spacing adjustment cam is provided on one side with a stitch spacing linkage. A drive part is formed on the stitch spacing linkage to push the stitch spacing adjustment cam. One end of the stitch spacing linkage is hinged to the machine body, and the other end of the stitch spacing linkage is hinged to a swing seat linkage. The other end of the swing seat linkage is hinged to the stitch spacing swing seat.

[0008] A lifting linkage is provided on one side of the lifting foot cam. A second driving part for the lifting foot cam to push is formed on the lifting linkage. One end of the lifting linkage is hinged to the machine body, and the other end of the lifting linkage is hinged to a lever linkage. The other end of the lever linkage is hinged to a lever on the lifting foot.

[0009] Preferably, the drive unit includes a mounting post mounted on the needle pitch connecting rod, and a roller is provided on the outer periphery of the mounting post.

[0010] Preferably, one end of the needle spacing connecting rod is connected to a mounting base via a hinge shaft, and the mounting base is mounted on the inner wall of the machine body via fasteners.

[0011] Preferably, the second drive unit includes a second mounting post mounted on the lifting and pressing link, and a second roller is provided on the outer periphery of the second mounting post.

[0012] Preferably, one end of the lifting and pressing link is connected to a mounting base two via a hinge shaft two, and the mounting base two is set on the inner side wall of the machine body by fasteners.

[0013] Preferably, one side of the swing seat connecting rod is formed with a hanging groove, a return spring is connected in the hanging groove, and the other end of the return spring is connected to the machine body.

[0014] The outstanding and beneficial technical effects of this utility model compared to the prior art are:

[0015] This invention utilizes a two-cam design to drive the presser foot lifting action or control the stitch length, achieving a one-to-two effect. Furthermore, the component structure is simple and the processing cost is low. In actual operation, when the motor shaft drives the stitch length adjustment cam to rotate, the first drive unit rotates the stitch length linkage, which in turn drives the oscillating seat linkage to rotate to different positions. Different oscillating seat positions correspond to different sewing machine stitch lengths, either forward or reverse stitching. When the motor shaft drives the presser foot lifting cam to rotate, the second drive unit rotates the presser foot lifting linkage, which in turn drives the lever on the presser foot to rotate via the lever linkage. Subsequently, the presser foot lifting action is achieved via a pull rod. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0017] Figure 2 This is a schematic diagram of the one-to-two mechanism in this utility model.

[0018] Figure 3 This is a schematic diagram of the needle spacing adjustment mechanism in this utility model.

[0019] Figure 4 This is a schematic diagram of the lifting pressure foot mechanism in this utility model.

[0020] Reference numerals: 1-Machine body; 2-Pitch swing seat; 3-Lifting lever for presser foot; 4-Stepper motor; 5-Main shaft; 6-Pitch adjustment cam; 7-Lifting cam for presser foot; 8-Pitch linkage; 9-Drive unit one;

[0021] 10-Swing seat connecting rod; 11-Lifting and pressing connecting rod; 12-Drive unit two; 13-Lever connecting rod; 14-Mounting column one; 15-Roller one; 16-Hinge shaft one; 17-Mounting seat one; 18-Mounting column two; 19-Roller two;

[0022] 20-Hinged shaft two; 21-Mounting base two; 22-Hanging groove; 23-Return spring. Detailed Implementation

[0023] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0024] like Figure 1-4 As shown, a one-to-two mechanism for a flat sewing machine includes a machine body 1. Inside the machine body 1, a stitch pitch swing seat 2 and a lever 3 for lifting the presser foot are rotatably arranged. A stepper motor 4 is installed on the side of the machine body 1. A main shaft 5 is arranged inside the stepper motor 4. A stitch pitch adjustment cam 6 and a presser foot lifting cam 7 are respectively installed on the main shaft 5.

[0025] A stitch pitch adjusting cam 6 is provided with a stitch pitch connecting rod 8 on one side. A drive part 9 for pushing the stitch pitch adjusting cam 6 is formed on the stitch pitch connecting rod 8. One end of the stitch pitch connecting rod 8 is hinged to the machine body 1, and the other end of the stitch pitch connecting rod 8 is hinged to a swing seat connecting rod 10. The other end of the swing seat connecting rod 10 is hinged to the stitch pitch swing seat 2.

[0026] A lifting foot cam 7 is provided with a lifting rod 11 on one side. A drive part 2 12 for the lifting foot cam 7 to push is formed on the lifting rod 11. One end of the lifting rod 11 is hinged to the machine body 1, and the other end of the lifting rod 11 is hinged to a lever rod 13. The other end of the lever rod 13 is hinged to the lever 3 on the lifting foot.

[0027] This invention utilizes a two-cam design to drive the presser foot lifting action or control the stitch length, achieving a one-to-two effect. Furthermore, the component structure is simple and the processing cost is low. In actual operation, when the motor shaft drives the stitch length adjustment cam 6 to rotate, the drive unit 1 9 can be pushed to rotate the stitch length connecting rod 8, which in turn drives the stitch length swing seat 2 to rotate to different positions via the swing seat connecting rod 10. Different positions of the swing seat correspond to different sewing machine stitch lengths, either forward or reverse stitching. When the motor shaft drives the presser foot lifting cam 7 to rotate, the drive unit 2 12 can be used to rotate the presser foot lifting connecting rod 11, which in turn drives the presser foot upper lever 3 to rotate via the lever connecting rod 13. Subsequently, the presser foot lifting action is achieved via a pull rod.

[0028] The drive unit 9 includes a mounting post 14 mounted on the needle pitch connecting rod 8. The outer periphery of the mounting post 14 is provided with a roller 15 that is pushed by the needle pitch adjusting cam 6, thereby reducing friction and having the advantages of shock absorption, noise reduction, and extended service life.

[0029] One end of the needle spacing connecting rod 8 is connected to the mounting base 17 via a hinge shaft 16. The mounting base 17 is set on the inner side wall of the machine body 1 by fasteners. This connection structure is simple and easy to disassemble and maintain.

[0030] The drive unit 2 12 includes a mounting post 2 18 mounted on the lifting and pressing connecting rod 11. The outer periphery of the mounting post 2 18 is provided with a roller 2 19 for the lifting foot cam 7 to push, thereby reducing friction and having the advantages of shock absorption, noise reduction and extended service life.

[0031] One end of the lifting and pressing connecting rod 11 is connected to the mounting base 21 via the hinge shaft 20. The mounting base 21 is set on the inner side wall of the body 1 by fasteners. This connection structure is simple and easy to disassemble and maintain.

[0032] One side of the swing seat connecting rod 10 is formed with a hanging groove 22, and a return spring 23 is connected inside the hanging groove 22. The other end of the return spring 23 is connected to the machine body 1 to realize the automatic reset of the swing seat connecting rod 10, the needle pitch connecting rod 8, and the needle pitch swing seat 2.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A twin feed mechanism for a lockstitch sewing machine, characterized by, The utility model relates to a needle gauge and presser foot lifting mechanism, which comprises a machine body (1), a needle gauge swing seat (2) and a presser foot upper lever (3) are rotatably arranged in the machine body (1) respectively, a stepping motor (4) is installed on the side of the machine body (1), a main shaft (5) is arranged in the stepping motor (4), a needle gauge adjusting cam (6) and a presser foot cam (7) are installed on the main shaft (5) respectively, One side of the needle gauge adjusting cam (6) is provided with a needle gauge connecting rod (8), the needle gauge connecting rod (8) is formed with a driving part one (9) for the needle gauge adjusting cam (6) to push, one end of the needle gauge connecting rod (8) is hinged to the machine body (1), the other end of the needle gauge connecting rod (8) is hinged with a swing seat connecting rod (10), the other end of the swing seat connecting rod (10) is hinged to the needle gauge swing seat (2). One side of the presser foot cam (7) is provided with a presser foot connecting rod (11), the presser foot connecting rod (11) is formed with a driving part two (12) for the presser foot cam (7) to push, one end of the presser foot connecting rod (11) is hinged to the machine body (1), the other end of the presser foot connecting rod (11) is hinged with a lever connecting rod (13), the other end of the lever connecting rod (13) is hinged to the presser foot upper lever (3).

2. The one-two mechanism of the lockstitch sewing machine according to claim 1, characterized in that: The driving part one (9) comprises a mounting column one (14) mounted on the needle gauge connecting rod (8), and a roller one (15) is arranged on the outer periphery of the mounting column one (14).

3. The twin feed mechanism of a lockstitch machine according to claim 1 or 2, characterized in that: One end of the needle gauge connecting rod (8) is connected with a mounting seat one (17) through a hinge shaft one (16), and the mounting seat one (17) is arranged on the inner side wall of the machine body (1) through fasteners.

4. The twin feed mechanism of the lockstitch machine according to claim 1, characterized in that: The driving part two (12) comprises a mounting column two (18) mounted on the presser foot connecting rod (11), and a roller two (19) is arranged on the outer periphery of the mounting column two (18).

5. The twin feed mechanism of the lockstitch machine according to claim 1 or 4, characterized in that: One end of the presser foot connecting rod (11) is connected with a mounting seat two (21) through a hinge shaft two (20), and the mounting seat two (21) is arranged on the inner side wall of the machine body (1) through fasteners.

6. The twin feed mechanism of the lockstitch sewing machine according to claim 1, characterized in that: One side of the swing seat connecting rod (10) is formed with a hanging groove part (22), a return spring (23) is connected in the hanging groove part (22), and the other end of the return spring (23) is connected with the machine body (1).

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