Improved one-driving-three driving mechanism of sewing machine

Abstract

The utility model provides an improved one-driving-three driving mechanism of a sewing machine, and belongs to the technical field of sewing machines. The improved one-driving-three driving mechanism of the sewing machine comprises a stitch length adjusting mechanism, a presser foot lifting mechanism, a thread trimming mechanism and a driving motor, a driving shaft of the driving motor is connected with a stitch length cam used for driving the stitch length adjusting mechanism to work, a presser foot lifting driving crank used for driving the presser foot lifting mechanism to work and a thread trimming driving crank used for driving the thread trimming mechanism to work, and the stitch length adjusting mechanism comprises a stitch length adjusting crank, a stitch length connecting rod and a feeding swing plate seat. The stitch length cam is arranged on a driving shaft of the driving motor in a sleeving mode, one end of the stitch length adjusting crank is connected to the wheel face of the stitch length cam in an abutting mode through the stitch length adjusting idler wheel, the other end of the stitch length adjusting crank is connected with one end of the stitch length connecting rod, and the other end of the stitch length connecting rod is connected with the feeding swing plate base. The stitch length adjusting mechanism, the presser foot lifting mechanism and the thread trimming mechanism can be controlled to act through the same driving motor, the number of driving sources can be effectively reduced, meanwhile, the structure is more compact, the occupied space is small, installation is convenient, and cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machines and relates to a sewing machine, in particular to an improved one-to-three driving mechanism of a sewing machine. Background Art

[0002] Sewing machines currently on the market all include a stitch adjustment mechanism, a thread trimmer mechanism, and a presser foot lifter mechanism. However, these mechanisms are often independent and driven by two separate drive sources. This results in complex structures, large space requirements, high costs, and inconvenient installation. A Chinese patent [Granted Announcement No.: CN106948096B] discloses a thread trimmer and presser foot lifter mechanism for a sewing machine and a sewing machine. The sewing machine thread trimming and presser foot lifting structure includes: a double-headed motor, a thread trimming cam assembly, and a presser foot lifting crank assembly. The thread trimming cam assembly includes a thread trimming cam disposed on a motor shaft at one end of the double-headed motor, a movement groove provided on the thread trimming cam, one end of the thread trimming cam connected to the thread trimming cam via a connecting pin, the connecting pin being disposed in the movement groove of the thread trimming cam, the other end of the thread trimming cam connected to a thread trimming shaft, and the thread trimming shaft connected to a thread trimming mechanism; the presser foot lifting crank assembly includes a presser foot lifting crank disposed on the motor shaft at the other end of the double-headed motor, an abutment provided on the presser foot lifting crank, and the abutment abutment abutment against a push rod of the presser foot lifting mechanism. Although the operation of the thread trimming mechanism and the presser foot lifting mechanism is controlled by a single drive source, the drive source is reduced, the structure is simpler, the space occupied is small, installation is convenient, and the cost is reduced. However, since it uses a double-headed motor for driving, the distance between the thread trimming mechanism and the presser foot lifting mechanism is large, the structure is not compact enough, and there are limitations on the installation position of the double-headed motor, that is, the double-headed motor needs to be installed on the front or rear side of the casing, which is inconvenient to use. In addition, the sewing machine with the above structure also needs to be equipped with an additional motor to drive the stitch length adjustment mechanism, and the structure is still relatively complicated. Summary of the Invention

[0003] The purpose of the utility model is to solve the above problems in the existing technology and to propose an improved one-to-three driving mechanism for a sewing machine.

[0004] The purpose of the utility model can be achieved through the following technical solutions: an improved one-to-three drive mechanism of a sewing machine, including a stitch length adjustment mechanism, a presser foot lifting mechanism, a thread trimming mechanism and a driving motor, characterized in that a stitch length cam for driving the stitch length adjustment mechanism to work, a presser foot lifting driving crank for driving the presser foot lifting mechanism to work and a thread trimming driving crank for driving the thread trimming mechanism to work are connected to the driving shaft of the driving motor, the stitch length adjustment mechanism includes a stitch length adjustment crank, a stitch length connecting rod and a feed swing plate seat, the stitch length cam is sleeved on the driving shaft of the driving motor, one end of the stitch length adjustment crank is connected to the wheel surface of the stitch length cam through the stitch length adjustment roller, the other end of the stitch length adjustment crank is connected to one end of the stitch length connecting rod, and the other end of the stitch length connecting rod is connected to the feed swing plate seat.

[0005] In the above-mentioned improved one-to-three driving mechanism of the sewing machine, the middle portion of the stitch length adjustment crank is hinged to the sewing machine casing through the stitch length crank support pin.

[0006] In the above-mentioned improved one-to-three driving mechanism of the sewing machine, the feed swing plate seat is hinged with a connecting rod assembly, the connecting rod assembly is connected to an eccentric wheel, and the eccentric wheel has an eccentric hole for being sleeved on the main shaft of the sewing machine.

[0007] In the above-mentioned improved one-to-three drive mechanism of the sewing machine, the presser foot lifting mechanism includes a presser foot lifting swing arm, an automatic presser foot lifting space pull rod, an automatic presser foot lifting lever, an automatic presser foot lifting pull rod, a presser foot lifting rear lever, and a presser foot lifting pull rod which are connected in sequence. A presser foot lifting roller is provided on the eccentric setting of the presser foot lifting drive crank relative to the drive shaft. One end of the presser foot lifting swing arm is abutted against the presser foot lifting roller, and the other end is connected to the automatic presser foot lifting space pull rod.

[0008] In the above-mentioned improved one-to-three driving mechanism of the sewing machine, the middle portion of the presser foot lifter swing arm is hinged to the sewing machine casing through the presser foot lifter driving crank pin.

[0009] In the above-mentioned improved one-to-three drive mechanism of the sewing machine, the thread trimming mechanism includes a thread trimming lever, a thread trimming connecting rod, a thread trimming rear crank, a thread trimming shaft and a thread trimming assembly. The thread trimming drive crank is eccentrically arranged relative to the drive shaft and is provided with a thread trimming roller for driving the thread trimming lever to swing. One end of the thread trimming lever is used to be connected to the thread trimming roller, and the other end is connected to the thread trimming rear crank, the thread trimming shaft and the thread trimming assembly connected in sequence through the thread trimming connecting rod.

[0010] In the above-mentioned improved one-to-three driving mechanism of the sewing machine, one end of the thread trimmer lever is formed into a fork opening for matching with the thread trimmer roller.

[0011] In the above-mentioned improved one-to-three driving mechanism of the sewing machine, the middle portion of the thread trimmer lever is hinged to the bracket via the thread trimmer driving crank pin, and the bracket is fixedly connected to the sewing machine casing.

[0012] In the above-mentioned improved one-to-three drive mechanism of the sewing machine, the stitch cam, the presser foot lifter drive crank and the thread trimmer drive crank are sequentially connected to the drive shaft from one end of the near drive motor to one end of the far drive motor.

[0013] Compared with the existing technology, the utility model can control the actions of the needle distance adjustment mechanism, the presser foot lifting mechanism, and the thread trimming mechanism through the same drive motor, which can effectively reduce the number of drive sources. At the same time, the structure is more compact, occupies less space, and is easy to install, reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural diagram of the present utility model.

[0015] Figure 2 It is a structural schematic diagram of the utility model from another angle.

[0016] In the figure, 1. drive shaft; 2. stitch length cam; 3. presser foot lifter drive crank; 4. thread trimmer drive crank; 5. stitch length adjustment crank; 6. stitch length connecting rod; 7. feed swing plate base; 8. stitch length crank support pin; 9. connecting rod assembly; 10. eccentric wheel; 1001. eccentric hole; 11. presser foot lifter swing arm; 12. automatic presser foot lifter space pull rod; 13. automatic presser foot lifter lever; 14. automatic presser foot lifter pull rod; 15. presser foot lifter rear lever; 16. presser foot lifter pull rod; 17. presser foot lifter roller; 18. presser foot lifter drive crank pin; 19. thread trimmer lever; 1901. fork mouth; 20. thread trimmer connecting rod; 21. thread trimmer rear crank; 22. thread trimmer shaft; 23. thread trimmer assembly; 24. thread trimmer roller; 25. thread trimmer drive crank pin; 26. bracket; 27. stitch length adjustment roller. DETAILED DESCRIPTION

[0017] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0018] Reference Figure 1 and Figure 2 This embodiment is an improved one-to-three drive mechanism for a sewing machine, comprising a stitch adjustment mechanism, a presser foot lifter mechanism, a thread trimmer mechanism, and a drive motor. The stitch adjustment mechanism, presser foot lifter mechanism, and thread trimmer mechanism are driven by the same drive motor. In this embodiment, the drive motor's drive shaft 1 is connected, from the proximal end to the distal end, to a stitch cam 2 for driving the stitch adjustment mechanism, a presser foot lifter drive crank 3 for driving the presser foot lifter mechanism, and a thread trimmer drive crank 4 for driving the thread trimmer mechanism.

[0019] Specifically, the stitch length adjustment mechanism includes a stitch length adjustment crank 5, a stitch length connecting rod 6 and a feed swing plate seat 7. The stitch length cam 2 is sleeved on the drive shaft 1 of the drive motor. The middle part of the stitch length adjustment crank 5 is hinged to the sewing machine housing through the stitch length crank support pin 8. One end of the stitch length adjustment crank 5 is connected to the wheel surface of the stitch length cam 2 through the stitch length adjustment roller 27. The other end of the stitch length adjustment crank 5 is connected to one end of the stitch length connecting rod 6. The other end of the stitch length connecting rod 6 is connected to the feed swing plate seat 7. The feed swing plate seat 7 is hinged with a connecting rod assembly 9. The connecting rod assembly 9 is connected to an eccentric wheel 10. The eccentric wheel 10 has an eccentric hole 1001 for being sleeved on the main shaft of the sewing machine.

[0020] The presser foot lifting mechanism includes a presser foot lifting swing arm 11, an automatic presser foot lifting space pull rod 12, an automatic presser foot lifting lever 13, an automatic presser foot lifting pull rod 14, a presser foot lifting rear lever 15, and a presser foot lifting pull rod 16, which are connected in sequence. A presser foot lifting drive crank 3 is eccentrically arranged relative to the drive shaft 1 and is provided with a presser foot lifting roller 17. The middle part of the presser foot lifting swing arm 11 is hinged to the sewing machine casing through a presser foot lifting drive crank pin 18. One end of the presser foot lifting swing arm 11 is abutted against the presser foot lifting roller 17, and the other end is connected to the automatic presser foot lifting space pull rod 12.

[0021] The thread trimming mechanism includes a thread trimming lever 19, a thread trimming connecting rod 20, a thread trimming rear crank 21, a thread trimming shaft 22 and a thread trimming assembly 23. The thread trimming drive crank 4 is eccentrically arranged relative to the drive shaft 1 and is provided with a thread trimming roller 24 for driving the thread trimming lever 19 to swing. The middle part of the thread trimming lever 19 is hinged to the bracket 26 through the thread trimming drive crank pin 25, and the bracket 26 is fixed to the sewing machine casing. One end of the thread trimming lever 19 is made into a fork mouth 1901 for adapting to the thread trimming roller 24, and the other end is connected to the thread trimming rear crank 21, the thread trimming shaft 22 and the thread trimming assembly 23 connected in sequence through the thread trimming connecting rod 20.

[0022] The working principle of this embodiment is as follows: the driving shaft 1 of the driving motor rotates, and the stitch length cam 2, presser foot lifting driving crank 3 and thread trimming driving crank 4 connected to the driving shaft rotate accordingly, and respectively drive the stitch length adjustment mechanism, presser foot lifting mechanism and thread trimming mechanism to work. Specifically, during the rotation of the stitch length cam 2, since its wheel surface always rests on the stitch length adjustment roller 27, it can drive the stitch length adjustment crank 5 to swing around the stitch length crank support pin 8, thereby driving the feeding swing plate seat 7 to swing through the stitch length connecting rod 6 to achieve stitch length adjustment; during the rotation of the presser foot lifting driving crank 3, the wheel surface of the presser foot lifting roller 17 located at its eccentric position always rests on the lower surface of one end of the presser foot lifting swing arm 11. When the presser foot lifting roller 17 rotates with the presser foot lifting driving crank 3, it can drive the presser foot lifting swing arm 11 to swing around the presser foot lifting driving crank pin 18, thereby sequentially passing through the automatic presser foot lifting space pull rod 12, the automatic presser foot lifting lever 13, the automatic presser foot lifting pull rod 14, The presser foot lifting rear lever 15 and the presser foot lifting rod 16 realize the presser foot lifting operation; the thread trimming roller 24 is located on the extension arm on the side of the thread trimming drive crank 4. When it rotates with the thread trimming drive crank 4, it can slide into the fork mouth 1901 of the thread trimming lever 19, and drive the thread trimming lever 19 to rotate around the thread trimming drive crank pin 25 on the eccentric setting relative to the drive shaft 1, thereby driving the thread trimming assembly 23 to work through the thread trimming connecting rod 20, the thread trimming rear crank 21, and the thread trimming shaft 22 in sequence. When the thread trimming roller 24 drives the thread trimming lever 19 to rotate a certain angle, the thread trimming roller 24 disengages from the fork mouth 1901, and the thread trimming lever 19 is reset along with the thread trimming assembly 23 and waits for the next operation.

[0023] This embodiment can simultaneously perform the actions of the presser foot lifting assembly, the stitch length adjustment assembly and the thread trimming assembly through the same drive motor 1, which can effectively reduce the number of drive sources. At the same time, the structure is more compact, occupies less space, and is easy to install, reducing costs.

[0024] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. An improved one-to-three drive mechanism for a sewing machine, comprising a stitch length adjustment mechanism, a presser foot lifting mechanism, a thread trimming mechanism and a drive motor, characterized in that: The drive shaft (1) of the drive motor is connected with a needle distance cam (2) for driving the needle distance adjustment mechanism, a presser foot lifting drive crank (3) for driving the presser foot lifting mechanism, and a thread trimming drive crank (4) for driving the thread trimming mechanism. The needle distance adjustment mechanism comprises a needle distance adjustment crank (5), a needle distance connecting rod (6), and a feed swing plate seat (7). The needle distance cam (2) is sleeved on the drive shaft (1) of the drive motor. One end of the needle distance adjustment crank (5) is connected to the wheel surface of the needle distance cam (2) through a needle distance adjustment roller (27). The other end of the needle distance adjustment crank (5) is connected to one end of the needle distance connecting rod (6), and the other end of the needle distance connecting rod (6) is connected to the feed swing plate seat (7).

2. The improved one-to-three driving mechanism for sewing machines according to claim 1, characterized in that: The middle portion of the stitch length adjustment crank (5) is hinged to the sewing machine housing via a stitch length crank support pin (8).

3. The improved one-to-three driving mechanism for sewing machines according to claim 2, characterized in that: The feed swing plate seat (7) is hingedly connected to a connecting rod assembly (9), and the connecting rod assembly (9) is connected to an eccentric wheel (10). The eccentric wheel (10) has an eccentric hole (1001) for being sleeved on a sewing machine main shaft.

4. The improved one-to-three driving mechanism for sewing machines according to claim 1, 2 or 3, characterized in that: The presser foot lifting mechanism comprises a presser foot lifting swing arm (11), an automatic presser foot lifting space pull rod (12), an automatic presser foot lifting lever (13), an automatic presser foot lifting pull rod (14), a presser foot lifting rear lever (15), and a presser foot lifting pull rod (16) which are connected in sequence. A presser foot lifting roller (17) is provided on the presser foot lifting driving crank (3) eccentrically arranged relative to the driving shaft (1). One end of the presser foot lifting swing arm (11) is abutted against the presser foot lifting roller (17), and the other end is connected to the automatic presser foot lifting space pull rod (12).

5. The improved one-to-three driving mechanism for sewing machines according to claim 4, characterized in that: The middle part of the presser foot lifting swing arm (11) is hinged to the sewing machine housing via a presser foot lifting driving crank pin (18).

6. The improved one-to-three driving mechanism for sewing machines according to claim 1, 2 or 3, characterized in that: The thread trimming mechanism comprises a thread trimming lever (19), a thread trimming connecting rod (20), a thread trimming rear crank (21), a thread trimming shaft (22) and a thread trimming assembly (23); the thread trimming driving crank (4) is eccentrically arranged relative to the driving shaft (1) and is provided with a thread trimming roller (24) for driving the thread trimming lever (19) to swing; one end of the thread trimming lever (19) is connected to the thread trimming roller (24), and the other end is connected to the thread trimming rear crank (21), the thread trimming shaft (22) and the thread trimming assembly (23) connected in sequence through the thread trimming connecting rod (20).

7. The improved one-to-three driving mechanism for sewing machines according to claim 6, characterized in that: One end of the thread trimming lever (19) is formed into a fork opening (1901) adapted to be matched with the thread trimming roller (24).

8. The improved one-to-three driving mechanism for sewing machines according to claim 7, characterized in that: The middle part of the thread trimming lever (19) is hinged to a bracket (26) via a thread trimming driving crank pin (25), and the bracket (26) is fixed to a sewing machine casing.

9. The improved one-to-three driving mechanism for sewing machines according to claim 1, 2 or 3, characterized in that: The stitch length cam (2), the presser foot lifting drive crank (3) and the thread trimming drive crank (4) are sequentially connected to the drive shaft (1) from one end of the near drive motor to one end of the far drive motor.

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