Lift presser foot and thread trimming device for chain stitch sewing machine

Abstract

The utility model belongs to sewing machine technical field, especially point to a kind of chain sewing machine's lift presser foot and thread trimming device;Driving element is provided on the outside of driving element support, the rotating part of the driving element is provided with lift presser foot thread trimming cam;Lift presser foot thread trimming cam includes disc part and cam portion, disc part is provided with thread trimming track, driving element support is provided with thread trimming shaft, one end of thread trimming drive push is set on thread trimming shaft, the other end extends into thread trimming track;Press bar is equipped with press bar guide, one end of press bar guide is connected with cam portion;Rotating part drives lift presser foot thread trimming cam rotation, respectively drive thread trimming drive push and press bar guide action execution lift presser foot thread trimming action;The utility model is driven by single driving element by design a lift presser foot thread trimming cam integrated with thread trimming track and cam portion, realizes orderly time-sharing drive thread trimming and lift presser foot action in rotation period, compact structure, effectively reduce manufacturing cost and equipment complexity.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology, and specifically refers to a presser foot lifting and thread cutting device for a chain sewing machine. Background Technology

[0002] In chain stitch, the stitch is formed by interlocking threads from a single needle. This single-needle chain structure gives it excellent elasticity and extensibility, making it particularly suitable for elastic fabrics such as knitwear. Therefore, it is widely used in sewing products such as T-shirts, sportswear, and underwear. However, a drawback of this stitch is that the stitch ends are prone to unraveling if not properly secured. Therefore, the reliability and accuracy of the thread-cutting action after sewing are crucial.

[0003] In the sewing process, after sewing is completed, two key actions usually need to be performed in sequence: thread cutting and lifting the presser foot. Existing technologies have many solutions dedicated to automating these actions. For example, Chinese utility model patent (authorization announcement number CN 217922579U) discloses an automatic thread-cutting chain-type flatbed sewing machine, which cleverly integrates multiple functions such as thread cutting, thread loosening, and thread push compensation through a drive mechanism including a sliding shaft and a reset component, demonstrating a high degree of integration.

[0004] However, such existing technical solutions have a common limitation: the two core functions of wire cutting and lifting the pressure foot usually require two independent drive systems (such as two motors or electromagnets) to drive them separately. Although this "one action, one drive" mode has relatively simple control logic, it also leads to drawbacks such as complex equipment structure, large space occupation, and increased manufacturing costs. Summary of the Invention

[0005] The purpose of this invention is to provide a presser foot lifting and thread cutting device for a chain sewing machine in which a single driving component drives the thread cutting and presser foot lifting actions respectively.

[0006] This utility model is implemented as follows: A presser foot lifting and thread cutting device for a chain sewing machine includes a machine housing, a presser bar disposed on the machine housing, and a drive component bracket disposed at one end of the machine housing. A drive component is disposed on the outer side of the drive component bracket, and the drive component has a rotating part, which passes through the drive component bracket. The end of the rotating part that extends out of the drive component bracket is provided with a lifting foot wire-cutting cam. The lifting foot wire cutting cam includes a disc portion and a cam portion located on the first side of the disc portion. A wire cutting track is provided on the second side of the disc portion, including a wire cutting idle stroke section and a wire cutting drive section. The cam surface of the cam section includes a pressure foot idle stroke section and a pressure foot drive section; The drive component bracket is provided with a wire-cutting shaft that can be moved up and down. One end of the wire-cutting drive push block is set on the wire-cutting shaft and the other end extends into the wire-cutting track, and is driven to move by the wire-cutting drive section of the wire-cutting track. A pressure rod guide is installed on the pressure rod, one end of which is in contact with the cam surface of the cam part and moves under the drive of the pressure foot drive section; The rotating part drives the lifting foot wire-cutting cam to rotate, which in turn drives the wire-cutting drive push block and the pressure rod guide to perform the lifting foot and wire-cutting actions without interfering with each other.

[0007] In the presser foot lifting and thread cutting device of the above-mentioned chain sewing machine, power transmission is achieved by setting rolling elements between the presser rod guide and the cam surface and / or between the thread cutting drive push block and the thread cutting track.

[0008] In the presser foot lifting and thread cutting device of the aforementioned chain sewing machine, the rolling element is a bearing, roller, or ball.

[0009] In the presser foot lifting and thread cutting device of the above-mentioned chain sewing machine, the drive component bracket is provided with an open chamber on the side adjacent to the machine housing, and the presser foot lifting and thread cutting cam is located in the chamber.

[0010] In the presser foot lifting and thread cutting device of the above-mentioned chain sewing machine, the inner wall of the chamber is provided with a sliding guide block, and a slider groove is provided on the sliding guide block. The thread cutting drive push block is provided with a sliding block, and the sliding block slides in the slider groove.

[0011] In the aforementioned presser foot lifting and thread cutting device of a chain sewing machine, a thread cutting shaft seat is provided on the inner wall of the chamber, an upper mounting hole is provided on the thread cutting shaft seat, and a lower mounting hole is provided at the corresponding position of the drive component bracket. The thread cutting shaft is movably connected to the drive component bracket through the upper mounting hole and the lower mounting hole, and bushings are provided on the upper mounting hole and the lower mounting hole.

[0012] In the aforementioned presser foot lifting and thread cutting device of a chain sewing machine, the driving component is a stepper motor, and the corresponding rotating part is a motor shaft.

[0013] In the presser foot lifting and thread cutting device of the above-mentioned chain sewing machine, the drive component, the presser foot thread cutting cam, the thread cutting shaft and the drive component bracket are assembled into an independent integrated module, which is detachably installed on the machine housing as a whole.

[0014] In the presser foot lifting and thread cutting device of the above-mentioned chain sewing machine, a protective cover is provided on the outside of the drive component, and the protective cover is installed on the drive component bracket.

[0015] The outstanding advantages of this utility model compared to the prior art are: 1. This utility model designs a wire-cutting cam that integrates a wire-cutting track and a cam section, and is driven by a single drive component. This enables the orderly time-sharing of wire-cutting and pressure-foot-lifting actions within the rotation cycle. The structure is compact, effectively reducing manufacturing costs and equipment complexity, while ensuring that the wire-cutting and pressure-foot-lifting actions are precise, reliable, and do not interfere with each other.

[0016] 2. This utility model modularly integrates core components such as the drive unit, presser foot lifting and thread-cutting cam, and thread-cutting shaft onto the drive unit bracket, achieving integrated assembly and disassembly of the presser foot lifting and thread-cutting device. Users can quickly upgrade a basic chain sewing machine to an automatic thread-cutting + presser foot model by adding the integrated module. Only a few corresponding parts need to be replaced, making the upgrade quick and convenient without replacing the entire machine or major mechanical structures. Maintenance is convenient, and compatibility is strong. The same integrated module can be adapted to various models of basic chain sewing machines. Attached Figure Description

[0017] Figure 1 This is a three-dimensional schematic diagram of the present invention (the lifting foot mechanism in the figure only includes the pressure rod).

[0018] Figure 2 yes Figure 1 An explosion diagram.

[0019] Figure 3 yes Figure 1 The left view.

[0020] Figure 4 yes Figure 3 AA sectional view.

[0021] Figure 5 This is a schematic diagram showing that one end of the wire-cutting drive push block of this utility model is set inside the wire-cutting track.

[0022] Figure 6 This is a schematic diagram of the pressure rod guide frame of this utility model installed on the pressure rod, and the pressure rod being set on the machine housing.

[0023] Figure 7 This is a schematic diagram of the present invention mounted on the casing.

[0024] Figure 8 This is a schematic diagram of the disc portion of the lifting pressure foot wire-cutting cam of this utility model.

[0025] Figure 9 This is a schematic diagram of the cam portion of the lifting pressure foot wire cutting cam of this utility model located on one side of the disc portion.

[0026] In the diagram: 1. Housing; 2. Pressure rod; 3. Drive component bracket; 4. Drive component; 5. Rotating part; 6. Lifting pressure foot wire cutting cam; 7. Disc part; 8. Cam part; 9. Wire cutting idle stroke section; 10. Wire cutting drive section; 11. Lifting pressure foot drive section; 12. Lifting pressure foot idle stroke section; 13. Wire cutting shaft; 14. Wire cutting drive push block; 15. Pressure rod guide frame; 16. Rolling element; 17. Chamber; 18. Sliding guide block; 19. Sliding block; 20. Wire cutting shaft seat; 21. Protective cover. Detailed Implementation

[0027] The present invention will be further described below with reference to specific embodiments. See also: Figure 1 —9: This utility model provides a presser foot lifting and thread cutting device for a chain sewing machine. The chain sewing machine includes a machine housing 1, a presser bar 2 mounted on the machine housing 1, and a drive component bracket 3 located at one end of the machine housing 1. A presser foot is mounted on the lower end of the presser bar 2. A drive component 4 is provided on the outer side of the drive component bracket 3. The drive component 4 has a rotating part 5, which passes through the drive component bracket 3. A presser foot lifting and thread cutting cam 6 is provided at the end of the rotating part 5 extending out of the drive component bracket 3. In this embodiment, the drive component 3 is a stepper motor, and the corresponding rotating part 5 is a motor shaft. The presser foot lifting and thread cutting cam 6 includes a disc part 7 and a cam part 8 located on the first side of the disc part 7. A thread cutting track is provided on the second side of the disc part 7. The thread cutting track includes a thread cutting drive section 10 and a thread cutting idle stroke section 9. The outline of the cam part 8 includes a presser foot lifting drive section 11 and a presser foot lifting idle stroke section 12. The drive component bracket 3 is provided with a wire cutting shaft 13 that can be moved up and down, and a cutter is installed at the lower end of the wire cutting shaft 13. One end of the wire-cutting drive push block 14 is mounted on the wire-cutting shaft 13, and the other end extends into the wire-cutting track, and is driven by the wire-cutting drive section 10 of the wire-cutting track. A pressure rod guide 15 is mounted on the pressure rod 2. One end of the pressure rod guide 15 is in contact with the cam surface of the cam part 8 and moves under the drive of the lifting pressure foot drive section 11 of the cam surface. During operation, the rotating part 5 of the drive member 4 drives the lifting pressure foot wire-cutting cam 6 to rotate. When it rotates to the point where the wire-cutting drive section 10 drives the wire-cutting drive push block 14 to move, it is in the wire-cutting state. At this time, one end of the corresponding pressure rod guide 15 is in contact with the lifting pressure foot idle stroke section 12 of the cam part 8. When it rotates to the point where the lifting pressure foot drive section 11 acts on the pressure rod guide 15, it is in the lifting pressure foot state, and the wire-cutting drive push block 14 is in contact with the wire-cutting idle stroke section 9, so that the lifting pressure foot and wire-cutting actions do not interfere with each other.

[0028] This invention designs a wire-cutting cam 6 that integrates a wire-cutting track and a cam section 8, and is driven by a single drive unit. This enables the orderly time-sharing of wire-cutting and pressure-foot-lifting actions within the rotation cycle. The structure is compact, effectively reducing manufacturing costs and equipment complexity, while ensuring that the wire-cutting and pressure-foot-lifting actions are precise, reliable, and do not interfere with each other.

[0029] Furthermore, the presser foot lifting and thread cutting cam 6 of this utility model integrates the functions of driving the presser foot lifting and thread cutting on two sides of the same cam, which is compact in structure, reduces the number of parts and cost, and fundamentally eliminates the risk of the two actions interfering with each other, ensuring the reliability and accuracy of the sewing machine.

[0030] Furthermore, power transmission is achieved between the pressure rod guide 15 and the cam surface, and / or between the wire cutting drive push block 14 and the wire cutting track, through the use of rolling elements 16. Specifically, the rolling element 16 is a bearing, roller, or ball, making the transmission more flexible.

[0031] It should be noted that the drive component bracket 3 of this invention has an open chamber 17 on the side adjacent to the housing 1, and the lifting foot wire-cutting cam 6 is located in this chamber 17. When the drive component bracket 3 is installed on the housing 1, it communicates with the inner cavity of the housing 1.

[0032] To ensure smooth up-and-down movement of the wire-cutting shaft 13, a sliding guide block 18 is provided on the inner wall of the chamber 17, and a sliding groove is provided on the sliding guide block 18. A sliding block 19 is provided on the wire-cutting drive push block 14, and the sliding block 19 is slidably disposed in the sliding groove.

[0033] In addition, a wire-cutting shaft seat 20 is provided on the inner wall of the chamber 17 of this utility model. An upper mounting hole is provided on the wire-cutting shaft seat 20, and a lower mounting hole is provided at the corresponding position of the drive component bracket 3. The wire-cutting shaft 13 is movably connected to the drive component bracket 3 through the upper mounting hole and the lower mounting hole. Bushings are provided on the upper mounting hole and the lower mounting hole to make the wire-cutting shaft 13 move up and down smoothly.

[0034] The present invention provides a protective cover 21 on the outside of the driving component 4, and the protective cover 21 is fixed on the driving component bracket 3.

[0035] As can be seen from the above, the drive component 4, the presser foot lifting and thread-cutting cam 6, and the thread-cutting shaft 13 of this utility model are all installed on the drive component bracket 3 to form an integrated module, and one end of the pressure rod guide 15 is in contact with the cam surface of the cam part 8. Therefore, the integrated module can be disassembled and assembled as a whole. Users can quickly upgrade a basic chain sewing machine to an automatic thread-cutting + presser foot lifting model by adding the integrated module. Only a few corresponding parts need to be replaced. The upgrade is quick and convenient, without the need to replace the whole machine or the main mechanical structure. It is easy to maintain, highly compatible, and the same integrated module can be adapted to various models of basic chain sewing machines.

[0036] The above embodiments are only one of the preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes made in accordance with the shape, structure and principle of this utility model should be covered within the protection scope of this utility model.

Claims

1. A presser foot lifting and thread cutting device for a chain sewing machine, comprising a machine housing (1), a presser bar (2) disposed on the machine housing (1), and a drive component bracket (3) disposed at one end of the machine housing (1), wherein a drive component (4) is disposed on the outer side of the drive component bracket (3), the drive component (4) having a rotating part (5), the rotating part (5) passing through the drive component bracket (3), characterized in that: The rotating part (5) is provided with a lifting foot wire cutting cam (6) at one end of the drive bracket (3). The lifting foot wire cutting cam (6) includes a disc part (7) and a cam part (8) located on the first side of the disc part (7). A wire cutting track is provided on the second side of the disc part (7), including a wire cutting idle stroke section (9) and a wire cutting drive section (10). The cam surface of the cam section (8) includes a lifting foot idle stroke section (12) and a lifting foot drive section (11). The drive bracket (3) is provided with a wire-cutting shaft (13) that can be moved up and down. One end of the wire-cutting drive push block (14) is set on the wire-cutting shaft (13), and the other end extends into the wire-cutting track and is driven by the wire-cutting drive section (10) of the wire-cutting track. A pressure rod guide (15) is installed on the pressure rod (2). One end of the pressure rod guide (15) is in contact with the cam surface of the cam part (8) and moves under the drive of the lifting pressure foot drive section (11). The rotating part (5) drives the lifting foot wire-cutting cam (6) to rotate, which in turn drives the wire-cutting drive push block (14) and the pressure rod guide (15) to perform the lifting foot and wire-cutting actions without interfering with each other.

2. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 1, characterized in that: Power transmission is achieved between the pressure rod guide (15) and the cam surface and / or between the wire cutting drive push block (14) and the wire cutting track by setting a rolling element (16).

3. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 2, characterized in that: The rolling element (16) is a bearing, a roller, or a ball.

4. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 1, characterized in that: The drive bracket (3) has an open chamber (17) on the side adjacent to the housing (1), and the lifting foot wire cutting cam (6) is located in the chamber (17).

5. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 4, characterized in that: The inner wall of the chamber (17) is provided with a sliding guide block, and a slider groove is provided on the sliding guide block. The wire cutting drive push block (14) is provided with a sliding block, and the sliding block is slidably disposed in the slider groove.

6. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 4, characterized in that: The inner wall of the chamber (17) is provided with a wire cutting shaft (13) seat, an upper mounting hole is provided on the wire cutting shaft (13) seat, and a lower mounting hole is provided at the corresponding position of the drive component bracket (3). The wire cutting shaft (13) is movably connected to the drive component bracket (3) through the upper mounting hole and the lower mounting hole. A bushing is provided on the upper mounting hole and the lower mounting hole.

7. A presser foot lifting and thread cutting device for a chain sewing machine according to any one of claims 1-6, characterized in that: The driving component (4) is a stepper motor, and the corresponding rotating part (5) is a motor shaft.

8. A presser foot lifting and thread cutting device for a chain sewing machine according to any one of claims 1-6, characterized in that: The drive unit (4), the lifting foot wire-cutting cam (6), the wire-cutting shaft (13), and the drive unit bracket (3) are assembled into an independent integrated module, which is detachably installed on the housing (1) as a whole.

9. The presser foot lifting and thread cutting device of a chain sewing machine according to claim 1, characterized in that: The drive component (4) is provided with a protective cover (21), which is mounted on the drive component bracket (3).

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