Thread passing structure of sewing machine

Abstract

The utility model belongs to the technical field of sewing machines. The problem that in the prior art, threading and removing of a covering thread are difficult is solved. The thread passing structure of the sewing machine comprises a first thread passing hole formed in a thread passing frame and a second thread passing hole formed in a supporting frame, a rocker arm frame is connected with a thread bonding plate with a third thread passing hole, and a machine shell is further connected with a tensioning frame with a fourth thread passing hole. The first thread passing hole, the third thread passing hole, the second thread passing hole and the fourth thread passing hole are sequentially distributed from top to bottom, the fourth thread passing hole, the third thread passing hole, the second thread passing hole and the first thread passing hole are sequentially distributed from left to right, and the first thread passing hole is formed in the front-back direction of the sewing machine. The second thread passing hole and the third thread passing hole are formed in the left-right direction of the sewing machine, and the fourth thread passing hole is formed in the up-down direction of the sewing machine. The utility model has the advantage of greatly facilitating the threading and removing operation of the covering thread.

Description

Technical Field

[0001] This utility model belongs to the field of sewing machine technology and relates to a thread guide structure for a sewing machine. Background Technology

[0002] Four-needle six-thread sewing machines, also known as curved arm sewing machines, are mainly used for joining and splicing fabrics. These machines sew the internationally recognized ISO 607 stitch, consisting of four top threads, one bottom thread, and one cover thread (also called a harzian thread). Currently, the lead-out cam mechanism of four-needle six-thread sewing machines is mounted on the main shaft inside the machine housing. During threading, the cover thread first passes through the thread clamp, then through the lead-out cam mechanism inside the machine housing, then exits from the housing and finally passes through the thread fork. Because the lead-out cam is located inside the machine housing, threading and unthreading the cover thread is relatively difficult, time-consuming, and labor-intensive. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a thread guide structure for sewing machines. The technical problem this invention aims to solve is the difficulty in threading and unthreading covered threads in existing four-needle six-thread sewing machines.

[0004] The objective of this utility model can be achieved through the following technical solutions:

[0005] A thread guide structure for a sewing machine, the sewing machine including a machine housing and a thread clamp assembly, a thread guide support assembly, and a thread guide rocker arm assembly respectively disposed on the machine housing. The thread clamp assembly includes a base frame connected to the machine housing and a cover thread clamp disposed on the base frame. The thread guide support assembly includes a support frame connected to the machine housing and a thread guide frame connected to the support frame. The thread guide rocker arm assembly includes a rocker arm shaft rotatably disposed on the machine housing and a rocker arm frame connected to the rocker arm shaft. The thread guide structure is characterized by including a first thread guide hole formed on the thread guide frame and a thread guide hole formed on the support frame. The second thread guide hole on the frame, the rocker arm frame connected to the thread-feeding plate with the third thread guide hole, and the tensioning frame with the fourth thread guide hole connected to the machine housing are arranged sequentially from top to bottom, and sequentially from left to right. The first thread guide hole is opened along the front-back direction of the sewing machine, the second and third thread guide holes are opened along the left-right direction of the sewing machine, and the fourth thread guide hole is opened along the up-down direction of the sewing machine.

[0006] Unlike existing four-needle six-thread sewing machines that use a built-in cam inside the machine housing to stitch the threads, this sewing machine uses an external stitching plate that swings back and forth with the rocker arm shaft to stitch the threads. It achieves the same function but greatly simplifies the threading and unstitching of the cover thread, thus solving the problem of difficult threading and unstitching of the cover thread in existing four-needle six-thread sewing machines.

[0007] Specifically, the cover thread first passes through the cover thread clamp, then through the first thread hole on the thread guide and the second thread hole on the support frame. Next, the cover thread passes through the third thread hole on the stitching plate and the fourth thread hole on the tensioning frame. The stitching plate connected to the rocker arm shaft acts like a stitching cam (the rocker arm shaft is connected to the main shaft via a connecting rod, meaning the rocker arm shaft can rotate synchronously with the main shaft; the transmission connection structure between the rocker arm shaft and the main shaft is the same as that of existing four-needle six-thread sewing machines). Finally, the cover thread is passed through the thread divider.

[0008] In the aforementioned thread guide structure of a sewing machine, the thread-feeding plate has a first mounting hole and a second mounting hole arranged adjacent to each other. The first mounting hole is a vertically oriented, oblong hole, and the second mounting hole is a round hole. The thread-feeding plate is connected to the rocker arm frame via a first bolt passing through the first mounting hole, and the thread-feeding plate is simultaneously connected to the rocker arm frame and the rocker arm shaft via a second bolt passing through the second mounting hole. This allows for better connection between the thread-feeding plate and the rocker arm frame and shaft. Furthermore, the vertically oriented, oblong first mounting hole on the thread-feeding plate allows for adjustment of the thread-feeding angle, thereby adjusting the amount of thread fed. This further solves the problem that the existing thread-feeding cam structure of four-needle six-thread sewing machines cannot adjust the amount of thread fed according to actual needs.

[0009] In the thread guide structure of the sewing machine described above, the first, second, and fourth thread guide holes are all round holes, while the third thread guide hole is a horizontally oriented, waist-shaped hole. This design prevents the cover thread from swinging arbitrarily at the first, second, and fourth thread guide holes after it is threaded through, and also ensures that there is a gap between the cover thread and the wall of the third thread guide hole in both the front-to-back direction, allowing the stitching plate to better perform the stitching operation when it swings back and forth.

[0010] In the thread guide structure of the sewing machine described above, the base frame is further provided with a first thread hole and a second thread hole. The cover thread clamp, the first thread hole, the second thread hole, and the first thread guide hole are arranged sequentially from front to back, and the first thread guide hole, the second thread hole, and the first thread guide hole are arranged sequentially from left to right. This makes the threading path of the cover thread more precise and also makes the cover thread easier to tension after threading.

[0011] In the thread guide structure of the sewing machine described above, the first thread hole and the second thread hole are respectively opened along the front-to-back direction of the sewing machine, and both the first thread hole and the second thread hole are round holes. This prevents the cover thread from swinging arbitrarily at the first thread hole and the second thread hole after threading.

[0012] Compared with existing technologies, the advantages of the thread guide structure of this sewing machine are as follows: Unlike existing four-needle six-thread sewing machines that use a built-in thread-feeding cam inside the machine casing to perform thread-feeding, the thread guide structure of this sewing machine achieves the thread-feeding operation by using an external thread-feeding plate that swings back and forth with the rocker arm shaft outside the machine casing. It achieves the same function but greatly facilitates the threading and unthreading operations, thus solving the problem that the threading and unthreading operations of existing four-needle six-thread sewing machines with covered threads are relatively difficult. Attached Figure Description

[0013] Figure 1 This is a three-dimensional structural diagram of the thread guide mechanism of this sewing machine.

[0014] Figure 2 This is a front view of the thread guide structure of this sewing machine.

[0015] Figure 3 This is an exploded view of the thread guide structure, thread guide rocker arm assembly, and thread beater plate of this sewing machine.

[0016] Figure 4 This is a three-dimensional structural diagram of the thread guide structure and thread support component of this sewing machine.

[0017] Figure 5 This is a schematic diagram of the thread guide structure of this sewing machine, covering the thread threading mechanism.

[0018] In the diagram, 1. Housing; 2. Wire clamp assembly; 2a. Base frame; 2b. Cover wire clamp; 3. Wire guide support assembly; 3a. Support frame; 3b. Wire guide frame; 4. Wire guide rocker arm assembly; 4a. Rocker arm shaft; 4b. Rocker arm frame; 5. First wire guide hole; 6. Second wire guide hole; 7. Wire punch plate; 7a. Third wire guide hole; 7b. First mounting hole; 7c. Second mounting hole; 8. Tensioning frame; 8a. Fourth wire guide hole; 9. First bolt; 10. Second bolt; 11. First wire threading hole; 12. Second wire threading hole; A. Cover wire. Detailed Implementation

[0019] 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.

[0020] A thread guide structure for a sewing machine, as shown in the reference. Figure 1-5The sewing machine includes a housing 1 and a thread clamp assembly 2, a thread guide support assembly 3, and a thread guide rocker arm assembly 4, all respectively mounted on the housing 1. The thread clamp assembly 2 includes a base frame 2a connected to the housing 1 and a cover thread clamp 2b mounted on the base frame 2a. The thread guide support assembly 3 includes a support frame 3a connected to the housing 1 and a thread guide frame 3b connected to the support frame 3a. The thread guide rocker arm assembly 4 includes a rocker arm shaft 4a rotatably mounted on the housing 1 and a rocker arm frame 4b connected to the rocker arm shaft 4a. The thread guide structure includes a first thread guide hole 5 formed on the thread guide frame 3b and a second thread guide hole 5 formed on the support frame 3a. The sewing machine has a thread guide hole 6, a thread-feeding plate 7 with a third thread guide hole 7a connected to the rocker arm 4b, and a tensioning frame 8 with a fourth thread guide hole 8a connected to the housing 1. The first thread guide hole 5, the third thread guide hole 7a, the second thread guide hole 6 and the fourth thread guide hole 8a are arranged sequentially from top to bottom, and the fourth thread guide hole 8a, the third thread guide hole 7a, the second thread guide hole 6 and the first thread guide hole 5 are arranged sequentially from left to right. The first thread guide hole 5 is opened along the front-back direction of the sewing machine, the second thread guide hole 6 and the third thread guide hole 7a are both opened along the left-right direction of the sewing machine, and the fourth thread guide hole 8a is opened along the up-down direction of the sewing machine.

[0021] Reference Figure 1 , Figure 2 and Figure 3 Specifically, the punch plate 7 has a first mounting hole 7b and a second mounting hole 7c arranged adjacent to each other. The first mounting hole 7b is a waist-shaped hole arranged vertically, and the second mounting hole 7c is a round hole. The punch plate 7 is connected to the rocker arm frame 4b by a first bolt 9 passing through the first mounting hole 7b, and the punch plate 7 is connected to both the rocker arm frame 4b and the rocker arm shaft 4a by a second bolt 10 passing through the second mounting hole 7c.

[0022] In this embodiment, the first wire-passing hole 5, the second wire-passing hole 6, and the fourth wire-passing hole 8a are all round holes, and the third wire-passing hole 7a is a waist-shaped hole arranged horizontally.

[0023] Reference Figure 1 and Figure 2 Furthermore, the base frame 2a is also provided with a first wire hole 11 and a second wire hole 12. The cover wire clamp 2b, the first wire hole 11, the second wire hole 12 and the first wire passage hole 5 are arranged sequentially from front to back, and the first wire passage hole 5, the second wire hole 12 and the first wire hole 11 are arranged sequentially from left to right.

[0024] In this embodiment, the first threading hole 11 and the second threading hole 12 are preferably opened along the front-back direction of the sewing machine, and both the first threading hole 11 and the second threading hole 12 are round holes.

[0025] When threading the sewing machine, the four top threads and one bottom thread are threaded in the same way as existing four-needle six-thread sewing machines. However, the threading method for the cover thread (also called harbour thread) is different from that of existing four-needle six-thread sewing machines. (Refer to...) Figure 5 Specifically, the cover thread A first passes through the cover thread clamp 2b, then passes through the first thread hole 11 and the second thread hole 12 on the base frame 2a in sequence. Then, the cover thread A passes through the first thread hole 5 on the thread guide frame 3b and the second thread hole 6 on the support frame 3a. Next, the cover thread A passes through the third thread hole 7a on the thread guide plate 7 and the fourth thread hole 8a on the tension frame 8 in sequence. The thread guide plate 7 connected to the rocker arm shaft 4a can play a role similar to a thread guide cam (the rocker arm shaft 4a is connected to the main shaft through a connecting rod, that is, the rocker arm shaft 4a can rotate synchronously with the main shaft. The transmission connection structure between the rocker arm shaft 4a and the main shaft is the same as that of the existing four-needle six-thread sewing machine and is not shown in the figure). Finally, the cover thread A is passed through the thread divider (the thread divider is the same as that of the existing four-needle six-thread sewing machine and is not shown in the figure). Compared to traditional four-needle six-thread sewing machines that use a built-in cam inside the machine housing to oscillate and stitch, this sewing machine's thread guide structure uses an external stitch plate 7 that oscillates back and forth with the rocker arm shaft 4a to achieve the same effect, but greatly simplifies threading and unstitching. In addition, the first mounting hole 7b on the stitch plate 7 of this sewing machine's thread guide structure is a vertically oriented oblong hole, allowing the mounting angle of the stitch plate 7 to be adjusted, thereby adjusting the amount of stitches stitched. This further solves the problem that the stitch cam structure of existing four-needle six-thread sewing machines cannot adjust the amount of stitches stitched according to actual needs.

[0026] 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 thread passing structure of a sewing machine, the sewing machine comprising a machine housing (1) and a thread clamp assembly (2), a thread passing support assembly (3) and a thread passing rocker arm assembly (4) arranged on the machine housing (1) respectively, the thread clamp assembly (2) comprising a base frame (2a) connected to the machine housing (1) and a thread clamp cover (2b) arranged on the base frame (2a), the thread passing support assembly (3) comprising a support frame (3a) connected to the machine housing (1) and a thread passing frame (3b) connected to the support frame (3a), the thread passing rocker arm assembly (4) comprising a rocker arm shaft (4a) rotatably arranged on the machine housing (1) and a rocker arm frame (4b) connected to the rocker arm shaft (4a), characterized in that, The line passing structure comprises a first line passing hole (5) formed on the line passing frame (3b) and a second line passing hole (6) formed on the support frame (3a), the rocker frame (4b) is connected with a line hitting plate (7) with a third line passing hole (7a), the shell (1) is further connected with a tension frame (8) with a fourth line passing hole (8a), the first line passing hole (5), the third line passing hole (7a), the second line passing hole (6) and the fourth line passing hole (8a) are sequentially arranged from top to bottom, the fourth line passing hole (8a), the third line passing hole (7a), the second line passing hole (6) and the first line passing hole (5) are sequentially arranged from left to right, the first line passing hole (5) is formed along the front-back direction of the sewing machine, the second line passing hole (6) and the third line passing hole (7a) are both formed along the left-right direction of the sewing machine, and the fourth line passing hole (8a) is formed along the up-down direction of the sewing machine.

2. The thread passing structure of a sewing machine according to claim 1, wherein The line hitting plate (7) is provided with a first mounting hole (7b) and a second mounting hole (7c) arranged adjacently, the first mounting hole (7b) is a waist-shaped hole arranged vertically, the second mounting hole (7c) is a circular hole, the line hitting plate (7) is connected with the rocker frame (4b) through a first bolt (9) penetrating the first mounting hole (7b), and the line hitting plate (7) is simultaneously connected with the rocker frame (4b) and the rocker shaft (4a) through a second bolt (10) penetrating the second mounting hole (7c).

3. The thread passing structure of a sewing machine according to claim 1, wherein The first line passing hole (5), the second line passing hole (6) and the fourth line passing hole (8a) are all circular holes, and the third line passing hole (7a) is a waist-shaped hole arranged horizontally.

4. The thread passing structure of a sewing machine according to claim 1 or 2 or 3, wherein The base frame (2a) is further provided with a first thread passing hole (11) and a second thread passing hole (12), the covering thread clamping device (2b), the first thread passing hole (11), the second thread passing hole (12) and the first line passing hole (5) are sequentially arranged from front to back, and the first line passing hole (5), the second thread passing hole (12) and the first thread passing hole (11) are sequentially arranged from left to right.

5. The thread passing structure of a sewing machine according to claim 4, wherein The first thread passing hole (11) and the second thread passing hole (12) are both formed along the front-back direction of the sewing machine, and the first thread passing hole (11) and the second thread passing hole (12) are both circular holes.

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