Chain stitch sewing machine

Abstract

The utility model belongs to sewing equipment technical field, especially chain stitch sewing machine, be provided with the feeding eccentric wheel on the upper shaft, be provided with the lifting tooth connecting rod crank on the lifting tooth shaft, the upper end of lifting tooth connecting rod is sleeved on the feeding eccentric wheel, and the lower end is rotatably connected with the lifting tooth connecting rod crank, be provided with the feeding connecting rod crank on the feeding shaft, one end of feeding connecting rod crank is suspended, and feeding long swing lever is rotatably connected with the both sides of the end respectively, feeding long swing lever is connected with the lower end of feeding connecting rod, the one end of feeding short swing board through feeding connecting rod pin, the upper end of feeding connecting rod is sleeved on the feeding eccentric wheel, and the other end of feeding short swing board is connected with swing seat through connecting rod pin respectively, the utility model improves feeding mechanism, tooth frame structure, upper and lower shaft transmission structure etc., makes it with certain commonality between ordinary flat sewing machine, and greatly reduces production cost, has remarkable economic benefit and maintenance convenience.

Description

Technical fields:

[0001] This utility model belongs to the field of sewing equipment technology, and specifically refers to a chain stitch sewing machine. Background technology:

[0002] A chain stitch sewing machine is a specialized device that uses chain stitches for sewing. Unlike the common lockstitch (formed by interlacing top and bottom threads), the chain stitch uses only one or a single thread to form a continuous chain-like stitch through self-linking loops, giving it unique characteristics and applications.

[0003] The internal transmission structure of existing chain stitch sewing machines employs a highly specialized design. Its core transmission components (such as the feed mechanism, thread take-up mechanism, and feed dog structure) lack structural and specification commonality with corresponding components in ordinary flatbed sewing machines. This specialized design leads to two problems: First, manufacturers must establish separate production lines and stock dedicated spare parts for chain stitch sewing machines, increasing manufacturing complexity and significantly raising production costs and inventory management pressures. Second, during equipment maintenance, reliance on specialized parts and repair services with specific technical capabilities is essential, resulting in extended maintenance cycles, increased downtime, and ultimately higher maintenance costs for end users.

[0004] Therefore, it is necessary to optimize the transmission structure of chain stitch sewing machines to improve their commonality with flatbed sewing machines in terms of some parts. Summary of the Invention:

[0005] The purpose of this invention is to provide a chain stitch sewing machine that can improve the versatility with flatbed sewing machines in terms of some parts, and reduce production and maintenance costs.

[0006] This utility model is implemented as follows:

[0007] A chain stitch sewing machine includes a feeding mechanism, a presser foot lifting mechanism, a needle bar, and a presser bar assembly. The feeding mechanism includes an upper shaft, a feeding shaft, and a lifting tooth shaft. A feeding eccentric wheel is mounted on the upper shaft. A lifting tooth connecting rod crank is mounted on the lifting tooth shaft. The upper end of the lifting tooth connecting rod is fitted onto the feeding eccentric wheel, and the lower end is rotatably connected to the lifting tooth connecting rod crank. A feeding connecting rod crank is also mounted on the feeding shaft. One end of the feeding connecting rod crank is suspended, and a long feeding swing rod is rotatably connected to both sides of this end. The long feeding swing rod is connected to the lower end of the feeding connecting rod and one end of a short feeding swing plate via a feeding connecting rod pin. The upper end of the feeding connecting rod is fitted onto the feeding eccentric wheel. The other end of the short feeding swing plate is connected to two arms of a swing seat via connecting rod pins. The two arms are connected to the machine housing via swing seat pins.

[0008] In the aforementioned chain stitch sewing machine, the swing seat is also connected to the feed adjuster via a reverse feed linkage. The feed adjuster is rotatably connected to the machine housing, and its position is adjusted by a reverse feed adjusting screw.

[0009] The chain stitch sewing machine described above also includes a lower shaft and a vertical shaft. The lower shaft is located at the left end of the swing seat. The upper end of the vertical shaft is connected to the upper shaft via an upper bevel gear assembly, and the lower part is connected to the lower shaft via a lower bevel gear set.

[0010] In the aforementioned chain stitch sewing machine, an oil pump is installed below the vertical shaft, and the lower end of the vertical shaft is connected to the oil pump as the power input shaft of the oil pump.

[0011] In the aforementioned chain stitch sewing machine, a lifting fork crank is provided at the left end of the lifting tooth shaft, and a tooth holder seat is provided at the left end of the feed shaft. One end of the tooth holder is rotatably connected to the tooth holder seat via a tooth holder pin, and the other end is provided with a lifting tooth slider pin. The lifting tooth slider pin is slidably disposed in the fork of the lifting fork crank, and the feed tooth is detachably fixed in the middle of the tooth holder.

[0012] In the aforementioned chain stitch sewing machine, the feed shaft is rotatably mounted on the base plate via a feed shaft front sleeve. The feed shaft front sleeve is fixed to the base plate. A retaining ring groove is provided at a corresponding position on the feed shaft, and a retaining ring is provided in the retaining ring groove. The feed shaft passes through the feed shaft front sleeve, and the retaining ring abuts against one end of the feed shaft front sleeve. A retaining ring is fixed on the feed shaft at the other end of the feed shaft front sleeve. The retaining ring and retaining ring achieve axial positioning of the feed shaft.

[0013] In the aforementioned chain stitch sewing machine, a thread take-up lever is detachably fixed to the needle bar. The thread take-up lever is arranged vertically, with its lower end set on the needle bar and its upper end set with a thread take-up frame. The thread take-up frame has a thread hole and is connected to the thread take-up lever via an extension arm. The thread take-up frame is located outside the machine housing. A thread clamping plate is also provided on the thread take-up frame via a thread clamping plate screw and a thread clamping spring.

[0014] In the aforementioned chain stitch sewing machine, the presser foot lifting mechanism includes a presser bar guide, a presser foot lifting plate, a front presser foot lifting lever, and a rear presser foot lifting lever. The front and rear presser foot lifting levers are rotatably mounted on the inner wall of the machine housing. The presser bar guide is mounted on the presser bar assembly. The lower end of the presser foot lifting plate is connected to the presser bar guide, and the upper end is connected to the front presser foot lifting lever. The front presser foot lifting lever is also connected to one end of the rear presser foot lifting lever via a pull rod. The other end of the rear presser foot lifting lever is driven to rotate by a drive component to lift the presser foot.

[0015] In the aforementioned chain stitch sewing machine, a rolling element is provided at the other end of the lever after lifting the presser foot, and the driving element has a telescopic part. The telescopic part acts on the rolling element to drive the lever after lifting the presser foot to swing, thereby lifting the presser foot.

[0016] The outstanding advantages of this utility model compared to the prior art are:

[0017] This invention, through improvements to the feeding mechanism, the toothed frame structure, and the upper and lower shaft transmission structure, significantly enhances the interchangeability and commonality of parts between chain stitch sewing machines and ordinary flatbed sewing machines while maintaining the performance of the chain stitch sewing machine. This substantially reduces production and maintenance costs, while simultaneously improving the overall reliability and ease of operation, demonstrating outstanding practical value and economic benefits. Attached image description:

[0018] Figure 1 This is a three-dimensional schematic diagram of the present invention;

[0019] Figure 2 This is one of the schematic diagrams of the various transmission mechanisms inside this utility model;

[0020] Figure 3 This is the second schematic diagram of the internal transmission mechanisms of this utility model;

[0021] Figure 4 This is a schematic diagram of the utility model with the bottom facing upwards;

[0022] Figure 5 This is a schematic diagram of the feeding mechanism and toothed frame structure of this utility model;

[0023] Figure 6 This is a schematic diagram of the thread take-up lever structure of this utility model installed on the needle bar;

[0024] Figure 7 This is a schematic diagram of the lifting and pressing foot mechanism of this utility model.

[0025] In the diagram: 1. Needle bar; 2. Pressure bar assembly; 3. Upper shaft; 4. Feed shaft; 5. Tooth lifting shaft; 6. Feed eccentric wheel; 7. Tooth lifting connecting rod crank; 8. Tooth lifting connecting rod; 9. Feed connecting rod crank; 10. Feed long swing rod; 11. Feed connecting rod; 12. Feed short swing plate; 13. Swing seat; 14. Swing seat pin; 15. Machine housing; 16. Reverse feeding connecting rod; 17. Feed regulator; 18. Reverse feeding adjusting stud; 19. Lower shaft; 20. Vertical shaft; 21. Oil pump; 2. Base plate; 23. Lifting fork crank; 24. Feeder bracket seat; 25. Feeder bracket; 26. Lifting slider pin; 27. Fork opening; 28. Feeding tooth; 29. ​​Feed shaft front bushing; 30. Snap ring; 31. Retaining ring; 32. Wire take-up lever; 33. Wire take-up frame; 34. Extension arm; 35. Wire clamping plate; 36. Pressure bar guide frame; 37. Pressure foot lifting plate; 38. Front lever for lifting pressure foot; 39. Rear lever for lifting pressure foot; 40. Pull rod; 41. Drive component; 42. Rolling component; 43. Telescopic part. Detailed implementation method:

[0026] The present invention will be further described below with reference to specific embodiments. See also: Figure 1 —7:

[0027] This utility model provides a chain stitch sewing machine, which includes a feeding mechanism, a presser foot lifting mechanism, a needle bar 1, and a presser bar assembly 2. Specifically, the feeding mechanism includes an upper shaft 3, a feeding shaft 4, and a feed dog lifting shaft 5. A feeding eccentric wheel 6 is provided on the upper shaft 2, and a feed dog lifting connecting rod crank 7 is provided on the feed dog lifting shaft 5. The upper end of the feed dog lifting connecting rod 8 is fitted onto the feeding eccentric wheel 6, and the lower end is rotatably connected to the feed dog lifting connecting rod crank 7. A feeding... The feeding connecting rod crank 9 has one end suspended, and feeding long swing rods 10 are rotatably connected to both sides of this end. The feeding long swing rods 10 are connected to the lower end of the feeding connecting rod 11 and one end of the feeding short swing plate 12 through the feeding connecting rod pin. The upper end of the feeding connecting rod 11 is fitted on the feeding eccentric wheel 6. The other end of the feeding short swing plate 12 is connected to the two arms of the swing seat 13 through the connecting rod pin. The two arms are connected to the machine housing 15 through the swing seat pin 14.

[0028] This utility model adopts the same feeding mechanism as a common flat sewing machine, which improves its versatility with common flat sewing machines.

[0029] In addition, the swing seat 13 is also connected to the feed regulator 17 via the reverse feeding connecting rod 16. The feed regulator 17 is rotatably connected to the machine housing 15. The feed regulator 17 is driven by the reverse feeding adjusting screw 18 to adjust the position, perform reverse and forward stitch adjustment and stitch length adjustment.

[0030] It is worth noting that the chain stitch sewing machine also includes a lower shaft 19 and a vertical shaft 20. This invention further shortens the axial dimension of the lower shaft 19 and positions it at the left end of the swing seat 13, which not only optimizes the structural compactness but also provides more reasonable installation space for the oil pump 21, further improving compatibility with ordinary flatbed sewing machines. Correspondingly, the upper end of the vertical shaft 20 is connected to the upper shaft 2 via an upper bevel gear assembly, and the lower part is connected to the lower shaft 19 via a lower bevel gear assembly. The upper shaft 2 is driven to rotate by a motor, which in turn drives the lower shaft 19 to rotate via the upper and lower bevel gear assemblies.

[0031] Meanwhile, an oil pump 21 is installed below the vertical shaft 20, and the oil pump 21 is fixed on the base plate 22. The lower end of the vertical shaft 20 is connected to the oil pump 21 as the power input shaft of the oil pump 21.

[0032] Regarding the tooth frame structure, the left end of the tooth lifting shaft 5 is provided with a tooth lifting fork crank 23, the left end of the feeding shaft 4 is provided with a tooth frame seat 24, one end of the tooth frame 25 is rotatably connected to the tooth frame seat 24 through a tooth frame pin, and the other end is provided with a tooth lifting slider pin 26. The tooth lifting slider pin 26 is slidably disposed in the fork 27 of the tooth lifting fork crank 23, and the feeding tooth 28 is detachably fixed in the middle of the tooth frame 25.

[0033] To facilitate the installation of the feeding shaft 4, this invention pre-machines a retaining ring groove on the feeding shaft 4, which determines the installation position of the feeding shaft 4. A front bushing 29 for the feeding shaft is provided on the base plate 22, and the feeding shaft 4 passes through the front bushing 29. Retaining rings 30 and retaining rings 31 are respectively provided on the feeding shaft 4 at both ends of the front bushing 29 to achieve axial positioning and installation of the feeding shaft 4. The retaining rings 30 and retaining rings 31 are attached to both end faces of the front bushing 29.

[0034] In addition, the present invention has a thread take-up lever 32 detachably fixed on the needle bar 1. The thread take-up lever 32 is arranged vertically, with its lower end set on the needle bar 1 and its upper end set with a thread take-up frame 33. The thread take-up frame 33 has a thread hole and is connected to the thread take-up lever 32 through an extension arm 34. The thread take-up frame 33 is located outside the machine housing 15. A thread clamping plate 35 is also provided on the thread take-up frame 33 through a thread clamping plate screw and a thread clamping spring.

[0035] Finally, the presser foot lifting mechanism includes a presser rod guide 36, a presser foot lifting plate 37, a front presser foot lifting lever 38, and a rear presser foot lifting lever 39. The front presser foot lifting lever 38 and the rear presser foot lifting lever 39 are rotatably mounted on the inner wall of the housing 15. The presser rod guide 36 is mounted on the presser rod assembly 2. The lower end of the presser foot lifting plate 37 is connected to the presser rod guide 36, and the upper end is connected to the front presser foot lifting lever 38. The front presser foot lifting lever 38 is also connected to one end of the rear presser foot lifting lever 39 via a pull rod 40. The other end of the rear presser foot lifting lever 39 is driven to rotate by a drive component 41 to lift the presser foot.

[0036] To ensure flexible transmission, this invention includes a rolling element 42 at the other end of the lever 39 after lifting the pressure foot. The driving element 41 has a telescopic portion 43, which acts on the rolling element 41 to drive the lever 39 to swing and thus lift the pressure foot. In this embodiment, the driving element is an electromagnet, the telescopic portion 43 is an iron core, and the rolling element 42 is a roller or bearing, which can reduce noise.

[0037] As can be seen from the above, this utility model, through improvements to the feeding mechanism, toothed structure, and upper and lower shaft transmission structure, significantly enhances the universality and interchangeability of spare parts between the chain stitch sewing machine and ordinary flat sewing machines while maintaining the performance of the chain stitch sewing machine. It also greatly reduces production and maintenance costs, while enhancing the overall reliability and ease of operation, thus possessing outstanding practical value and economic benefits.

[0038] 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 chain stitch sewing machine, comprising a feeding mechanism, a presser foot lifting mechanism, a needle bar (1), and a presser bar assembly (2), characterized in that: The feeding mechanism includes an upper shaft (3), a feeding shaft (4), and a lifting shaft (5). A feeding eccentric wheel (6) is provided on the upper shaft (3), and a lifting connecting rod crank (7) is provided on the lifting shaft (5). The upper end of the lifting connecting rod (8) is fitted onto the feeding eccentric wheel (6), and the lower end is rotatably connected to the lifting connecting rod crank (7). A feeding connecting rod crank (9) is provided on the feeding shaft (4), and one end of the feeding connecting rod crank (9) is suspended in the air. The feeding long swing rod (10) is rotatably connected to both sides of the end. The feeding long swing rod (10) is connected to the lower end of the feeding connecting rod and one end of the feeding short swing plate (12) through the feeding connecting rod pin. The upper end of the feeding connecting rod (11) is fitted on the feeding eccentric wheel (6). The other end of the feeding short swing plate (12) is connected to the two arms of the swing seat (13) through the connecting rod pin. The two arms are connected to the machine housing (15) through the swing seat pin.

2. The chain stitch sewing machine according to claim 1, characterized in that: The swing seat (13) is also connected to the feeding regulator (17) via the reverse feeding connecting rod (16). The feeding regulator (17) is rotatably connected to the housing (15). The feeding regulator (17) is driven to adjust its position by the reverse feeding adjusting screw (18).

3. A chain stitch sewing machine according to claim 1, characterized in that: It also includes a lower shaft (19) and a vertical shaft (20). The lower shaft (19) is located at the left end of the swing seat (13). The upper end of the vertical shaft (20) is connected to the upper shaft (3) through an upper bevel gear assembly, and the lower part is connected to the lower shaft (19) through a lower bevel gear set.

4. A chain stitch sewing machine according to claim 3, characterized in that: An oil pump (21) is provided below the vertical shaft (20), and the lower end of the vertical shaft (20) is connected to the oil pump (21) as the power input shaft of the oil pump (21).

5. A chain stitch sewing machine according to claim 1, characterized in that: The left end of the lifting shaft (5) is provided with a lifting fork crank (23), the left end of the feeding shaft (4) is provided with a tooth holder seat (24), one end of the tooth holder (25) is rotatably connected to the tooth holder seat (24) through a tooth holder pin, and the other end is provided with a lifting slider pin (26). The lifting slider pin (26) is slidably disposed in the fork (27) of the lifting fork crank (23), and the feeding tooth (28) is detachably fixed in the middle of the tooth holder (25).

6. A chain stitch sewing machine according to claim 5, characterized in that: The feeding shaft (4) is rotatably mounted on the base plate (22) via the front bushing (29) of the feeding shaft. The front bushing (29) of the feeding shaft is fixed on the base plate (22). A snap ring groove is provided at a corresponding position on the feeding shaft (4), and a snap ring (30) is provided in the snap ring groove. The feeding shaft (4) passes through the front bushing (29), and the snap ring (30) abuts against one end of the front bushing (29). A retaining ring (31) is fixed on the feeding shaft (4) at the other end of the front bushing (29). The snap ring (30) and the retaining ring (31) realize the axial positioning of the feeding shaft (4).

7. A chain stitch sewing machine according to claim 1, characterized in that: A thread take-up lever (32) is detachably fixed on the needle bar (1). The thread take-up lever (32) is arranged vertically, with its lower end set on the needle bar (1) and its upper end set with a thread take-up frame (33). The thread take-up frame (33) has a thread hole and is connected to the thread take-up lever (32) through an extension arm (34). The thread take-up frame (33) is located outside the machine housing (15). A thread clamping plate (35) is also provided on the thread take-up frame (33) through a thread clamping plate screw and a thread clamping spring.

8. A chain stitch sewing machine according to claim 1, characterized in that: The presser foot lifting mechanism includes a presser rod guide (36), a presser foot lifting plate (37), a presser foot lifting front lever (38), and a presser foot lifting rear lever (39). The presser foot lifting front lever (38) and the presser foot lifting rear lever (39) are rotatably mounted on the inner wall of the housing (15). The presser rod guide (36) is mounted on the presser rod assembly (2). The lower end of the presser foot lifting plate (37) is connected to the presser rod guide (36), and the upper end is connected to the presser foot lifting front lever (38). The presser foot lifting front lever (38) is also connected to one end of the presser foot lifting rear lever (39) through a pull rod (40). The other end of the presser foot lifting rear lever (39) is driven to rotate by a drive component (41) to lift the presser foot.

9. A chain stitch sewing machine according to claim 8, characterized in that: The other end of the lifting foot lever (39) is provided with a rolling element (42), and the driving element (41) has a telescopic part (43). The telescopic part (43) acts on the rolling element (42) to drive the lifting foot lever (39) to swing and thus lift the pressing foot.

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