A thread-cutting mechanism and a tube-type sewing machine

Abstract

This utility model provides a thread-cutting mechanism and a cylindrical sewing machine, belonging to the field of sewing machine technology. It solves the technical problems of short service life of existing thread-cutting mechanisms in sewing machines. The thread-cutting mechanism includes a thread-cutting blade, a drive lever, a thread-cutting lever assembly, and a transmission lever assembly. The thread-cutting blade is fixed on the thread-cutting lever, and the transmission lever assembly connects the drive lever and the thread-cutting lever. The thread-cutting mechanism also includes a motor, a drive component, and a transmission component. One end of the drive lever is fixed to a rotating shaft, and the transmission component is fixedly mounted on the rotating shaft. The motor shaft is connected to the drive component, driving the drive component to rotate. The drive component is connected to the transmission component, driving the transmission component to rotate. This utility model has the advantages of long service life and low maintenance cost.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology, and relates to a thread cutting mechanism and a tube sewing machine. Background Technology

[0002] The application of thread-cutting mechanisms in sewing machines is becoming increasingly widespread. For example, Chinese patent literature discloses a thread-cutting device for sewing machines and a sewing machine containing such a device [Application No. 202422060246.X]. The thread-cutting device includes a blade, a primary swing arm mechanism, a secondary swing arm mechanism, a tertiary swing arm mechanism, and a telescopic component, all sequentially connected inside the sewing machine panel. The primary, secondary, and tertiary swing arm mechanisms and the telescopic component are all connected to the sewing machine panel. The blade is located on one side above the bobbin case inside the sewing machine panel. The sewing machine includes a machine head and a sewing machine panel. The thread-cutting device is installed inside the sewing machine panel, and the blade is located to the lower right of the feed dog at the end of the sewing machine panel. The telescopic component drives the primary, secondary, and tertiary swing arm mechanisms to swing the blade.

[0003] The patent is the applicant's existing design. The wire cutting mechanism of the patent is driven by a telescopic component, which moves linearly, while the three-stage cam moves rotaryly. This requires opening a strip hole on the three-stage cam to enable the telescopic component to drive the three-stage cam to swing. In practice, after long-term use, the connection of the strip hole will wear, causing the connection to jam and produce abnormal noise, resulting in a short service life. Utility Model Content

[0004] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a wire-cutting mechanism. The technical problem solved by this invention is to improve the service life of the wire-cutting mechanism.

[0005] The objective of this utility model can be achieved through the following technical solutions:

[0006] A wire-cutting mechanism includes a wire-cutting blade, a drive lever, a wire-cutting lever assembly, and a transmission lever assembly. The wire-cutting blade is fixed on the wire-cutting lever, and the transmission lever assembly is connected between the drive lever and the wire-cutting lever. The mechanism further includes a motor, a drive component, and a transmission component. One end of the drive lever is fixed to a rotating shaft, and the transmission component is fixedly mounted on the rotating shaft. The motor shaft is connected to the drive component, driving the drive component to rotate. The drive component is connected to the transmission component, driving the transmission component to rotate.

[0007] In the aforementioned wire-cutting mechanism, both the driving and transmission components are gears, and the driving and transmission components mesh with each other. Smooth rotation of the drive shaft is achieved through gear transmission, enabling the wire-cutting blade to cut the wire. Gear transmission results in less wear, a longer service life, and lower maintenance costs.

[0008] In the above-mentioned wire-cutting mechanism, the central axis of the driving component is perpendicular to the central axis of the transmission component, and both the driving component and the transmission component are helical cylindrical gears.

[0009] In the above-mentioned wire-cutting mechanism, the central axis of the driving component is parallel to the central axis of the transmission component, and both the driving component and the transmission component are spur gears.

[0010] In another scenario, in the aforementioned wire-cutting mechanism, both the driving component and the transmission component are pulleys, connected by a belt. The belt drives the transmission component to rotate, smoothly rotating the shaft and enabling the wire-cutting blade to cut the wire. Belt drives experience less wear, have a long service life, and low maintenance costs.

[0011] In the wire-cutting mechanism described above, the transmission ratio between the driving component and the transmission component is greater than 1. This increases the output torque of the transmission component, thereby ensuring that the wire-cutting blade can cut the wire.

[0012] In another scenario, in the aforementioned wire-cutting mechanism, the driving component is an arc-shaped cam, and the transmission component is a driven turntable. The rollers of the driven turntable engage with the cam grooves of the arc-shaped cam. The rotation of the arc-shaped cam drives the driven turntable to rotate. By rotating the arc-shaped cam back and forth with a motor, the driven turntable can rotate back and forth along the cam groove, achieving smooth rotation of the drive shaft and enabling the wire-cutting blade to cut the wire. The rollers of the driven turntable and the arc-shaped cam experience rolling friction, resulting in minimal wear, a long service life, and low maintenance costs.

[0013] In another scenario, in the aforementioned wire-cutting mechanism, the driving component is a driving fork, and the transmission component is a driven fork. A connecting shaft connects the driving fork and the driven fork, and both the connecting shaft and the driving fork, as well as the connecting shaft and the driven fork, are connected via a cross shaft. The driving fork, driven fork, and connecting shaft form a universal joint. The motor drives the driving fork to rotate, which in turn drives the driven fork to rotate synchronously via the connecting shaft. This smoothly drives the rotating shaft to rotate, enabling the wire-cutting blade to cut the wire. This universal joint structure is wear-free, has a long service life, and low maintenance costs.

[0014] A tube sewing machine includes a base, characterized in that the aforementioned thread-cutting mechanism is mounted on the base.

[0015] Compared with the prior art, this utility model has the following advantages: it uses a motor to cut the wire, which can respond quickly and can be easily adapted to the controller to achieve automatic wire cutting; the driving and transmission components have a long service life and low maintenance costs. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the wire-cutting mechanism installed in the machine base in Embodiment 1.

[0017] Figure 2This is a three-dimensional structural diagram of the wire-cutting mechanism in Embodiment 1.

[0018] Figure 3 This is a front view of the wire-cutting mechanism in Embodiment 1 when it is not cutting the wire.

[0019] Figure 4 This is a front view structural diagram of the wire-cutting mechanism in Embodiment 1 during wire cutting.

[0020] In the diagram, 1 is the base; 2 is the wire cutter blade; 21 is the wire cutter lever; 22 is the first rotating shaft; 3 is the drive lever; 31 is the rotating shaft; 4 is the second rotating shaft; 41 is the second connecting rod; 42 is the third connecting rod; 5 is the motor; 51 is the driving component; 52 is the transmission component; and 53 is the drive shaft. Detailed Implementation

[0021] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0022] Example 1

[0023] like Figures 1 to 4 As shown, the tube sewing machine includes a base 1 and a thread-cutting mechanism. The thread-cutting mechanism includes a thread-cutting blade 2, a drive rocker arm 3, a thread-cutting rocker arm 21, and a transmission rocker arm assembly. The thread-cutting blade 2 is fixed to one end of the thread-cutting rocker arm 21 and located at the front end of the base 1. The other end of the thread-cutting rocker arm 21 is rotatably connected to the base 1 via a rotating shaft 22. One end of the drive rocker arm 3 is fixed to a rotating shaft 31, which is rotatably connected to the rear of the base 1. The transmission rocker arm assembly connects the drive rocker arm 3 and the thread-cutting rocker arm 21. The transmission rocker arm assembly includes a rotating shaft 4, a two-link rod 41, and a three-link rod 42. Rod 42 and rotating shaft 2 are rotatably connected to the machine base 1 and located between rotating shaft 31 and rotating shaft 22. One end of the two-link rod 41 is hinged to the other end of the drive swing rod 3, and the other end of the two-link rod 41 is fixedly connected to rotating shaft 24. One end of the three-link rod 42 is fixedly connected to rotating shaft 24, and the other end of the three-link rod 42 is fixedly connected to rotating shaft 22. In this embodiment, the rod at the other end of the two-link rod 41 and the rod at one end of the three-link rod 42 are integrated into one structure, reducing the number of parts. The specific structure of the transmission swing rod assembly can be adjusted and designed according to the actual sewing machine model.

[0024] The wire-cutting mechanism also includes a motor 5, a drive component 51, and a transmission component 52. The motor 5 is preferably a stepper motor, which is fixedly mounted on the external rear end of the base 1. In this embodiment, both the drive component 51 and the transmission component 52 are gears. The transmission component 52 is fixedly mounted on the rotating shaft 31, and the drive component 51 meshes with the transmission component 52. The transmission ratio between the drive component 51 and the transmission component 52 is greater than 1. A drive shaft 53 is fixed on the drive component 51, and the drive shaft 53 is rotatably connected to the base 1 via bearings at both ends. The motor shaft of the motor 5 extends into the base 1 and is connected to the drive shaft 53 via a coupling. In this embodiment, the drive shaft 53 is perpendicular to the rotating shaft 31, meaning the central axis of the drive component 51 is perpendicular to the central axis of the transmission component 52. Both the transmission component 52 and the drive component 51 are helical cylindrical gears. The transmission ratio between the transmission component 52 and the drive component 51 is set according to actual needs; in this embodiment, a transmission ratio of 2:1 is preferred.

[0025] The specific working principle is as follows: The motor 5 rotates, driving the drive component 51 to rotate, which in turn drives the transmission component 52 to rotate, causing the rotating shaft 31 to drive the drive rocker arm 3 to swing. This drives the rotating shaft 4 to rotate through the two connecting rods 41, which in turn drives the rotating shaft 22 to rotate through the three connecting rods 42. Finally, this drives the wire-cutting rocker arm 21 to swing, thus realizing the wire-cutting swing of the wire-cutting blade 2. After completion, the motor 5 reverses, and the above process is reversed to realize the reset of the wire-cutting blade 2, completing one wire-cutting action.

[0026] Example 2

[0027] This embodiment is basically the same as the first embodiment in terms of structure and principle. The difference is that both the driving component and the transmission component are pulleys, the central axis of the driving component and the central axis of the transmission component are parallel, a belt is provided between the driving component and the transmission component, and the driving component is fixed on the motor shaft of the motor.

[0028] Example 3

[0029] This embodiment is basically the same as the first embodiment in terms of structure and principle. The difference is that both the driving component and the transmission component are sprockets, the central axis of the driving component and the central axis of the transmission component are parallel, a chain is provided between the driving component and the transmission component, and the driving component is fixed on the motor shaft of the motor.

[0030] Example 4

[0031] The structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the drive shaft is parallel to the rotating shaft, and both the transmission component and the drive component are spur gears.

[0032] Example 5

[0033] This embodiment is basically the same as Embodiment 1 in structure and principle, except that the driving component is an arc-shaped cam, the transmission component is a driven turntable, and the rollers of the driven turntable cooperate with the cam groove of the arc-shaped cam. The above structure is an arc-shaped cam transmission mechanism. The rotation of the arc-shaped cam can drive the driven turntable to rotate. By rotating the arc-shaped cam back and forth with a motor, the driven turntable can rotate back and forth along the cam groove, so as to smoothly drive the rotating shaft to rotate and realize the cutting of the wire by the wire shearing blade.

[0034] Example 6

[0035] This embodiment is basically the same as Embodiment 1 in structure and principle, except that: the driving component is the active fork, the transmission component is the driven fork, and a connecting shaft connects the active and driven forks. The connecting shaft and the active fork, as well as the connecting shaft and the driven fork, are connected by a cross shaft. The active fork, the driven fork, and the connecting shaft form a universal joint. The motor drives the active fork to rotate, which in turn drives the driven fork to rotate synchronously through the connecting shaft, thus smoothly driving the rotating shaft to rotate and enabling the wire-cutting blade to cut the wire.

[0036] Example 7

[0037] The structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the drive component is directly mounted on the motor shaft of the motor.

[0038] Example 8

[0039] The structure and principle of this embodiment are basically the same as those of Embodiment 1. The difference is that the transmission ratio of the driving component and the transmission component is 3:1.

[0040] 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 wire-cutting mechanism, comprising a wire-cutting blade (2), a driving lever (3), a wire-cutting lever (21), and a transmission lever assembly, wherein the wire-cutting blade (2) is fixed on the wire-cutting lever (21), and the transmission lever assembly is connected between the driving lever (3) and the wire-cutting lever (21), characterized in that, The wire cutting mechanism also includes a motor (5), a drive component (51), and a transmission component (52). One end of the drive swing rod (3) is fixed with a rotating shaft (31). The transmission component (52) is fixedly installed on the rotating shaft (31). The motor shaft of the motor (5) is connected to the drive component (51) to drive the drive component (51) to rotate. The drive component (51) is connected to the transmission component (52) to drive the transmission component (52) to rotate.

2. The wire-cutting mechanism according to claim 1, characterized in that, Both the driving component (51) and the transmission component (52) are gears, and the driving component (51) and the transmission component (52) mesh.

3. The wire-cutting mechanism according to claim 2, characterized in that, The central axis of the driving component (51) is perpendicular to the central axis of the transmission component (52), and both the driving component (51) and the transmission component (52) are helical cylindrical gears.

4. The wire-cutting mechanism according to claim 2, characterized in that, The central axis of the driving component (51) is parallel to the central axis of the transmission component (52), and both the driving component (51) and the transmission component (52) are spur gears.

5. The wire-cutting mechanism according to claim 1, characterized in that, Both the driving component (51) and the transmission component (52) are pulleys, and a belt is provided between the driving component (51) and the transmission component (52).

6. The wire-cutting mechanism according to any one of claims 2 to 5, characterized in that, The transmission ratio of the driving component (51) and the transmission component (52) is greater than 1.

7. The wire-cutting mechanism according to claim 1, characterized in that, The driving component (51) is an arc-shaped cam, and the transmission component (52) is a driven turntable. The rollers of the driven turntable cooperate with the cam groove of the arc-shaped cam.

8. The wire-cutting mechanism according to claim 1, characterized in that, The driving component (51) is an active fork, the transmission component (52) is a driven fork, and a connecting shaft is connected between the active fork and the driven fork. The connecting shaft and the active fork, as well as the connecting shaft and the driven fork, are all connected by a cross shaft.

9. A tube-type sewing machine, comprising a machine base (1), characterized in that, The base (1) is equipped with a wire-cutting mechanism according to any one of claims 1 to 8.

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