Thread guiding device for a sewing machine

Abstract

The utility model provides a kind of thread shifting device of sewing machine, belong to sewing machine technical field.This thread shifting device includes pole, driving part and transmission structure, transmission structure is arranged in shell and includes support plate, linkage plate and connecting rod, support plate is parallel with the end surface of shell and is fixedly connected in shell, linkage plate is parallel and is stacked on support plate and is hinged with support plate, and it can swing relative to support plate under the driving of driving part, arc-shaped hole is opened on support plate, strip-shaped hole is opened on linkage plate and is arranged with arc-shaped hole cross, pulley is fixed on connecting rod, pulley is located in strip-shaped hole and arc-shaped hole and is slidably engaged with both, guide structure is equipped in shell, connecting rod can keep vertical in moving by guide structure, the lower end of connecting rod projects shell and is fixedly connected with pole.This thread shifting device can be basically completely hidden design into shell, to avoid its interference to the sewing work of sewing machine, it is favorable to improve the efficiency of sewing work.

Description

Technical Field

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

[0002] Currently, sewing machines are highly automated, and the actions of thread picking, hooking, cutting, and pulling in the traditional sewing process have been replaced by automated mechanical structures. Among them, the automatic thread pulling device is an important component of the sewing machine. After the automatic thread cutting device in the sewing machine cuts the needle thread, the automatic thread pulling device pulls the needle thread back up from the needle plate hole, so that the needle thread can start sewing smoothly in the second stitch, avoiding bird's nest or thread tangling.

[0003] For example, Chinese patent document CN201901758U discloses a thread-picking device for a sewing machine, which is mounted on the machine casing. This device includes a rotating shaft and a hook-shaped lever for thread picking. The rotating shaft is fixed to the machine casing, and the lever is fixedly connected to the rotating shaft. The device also includes a cylinder, which is fixedly connected to the machine casing. A transmission mechanism is provided between the cylinder and the rotating shaft, allowing the rotating shaft to reciprocate when the piston rod of the cylinder extends or retracts. The transmission mechanism includes a swing block circumferentially fixed to the end of the rotating shaft and a connecting block fixedly fixed to the end of the piston rod of the cylinder. The connecting block has a sliding groove, and the swing block is hinged to the connecting block via a pin that passes through and slides in the groove. This thread-picking device, driven by a cylinder, has advantages such as stable and precise thread picking, powerful thread picking, and low manufacturing cost.

[0004] However, the above-mentioned thread-shifting device has the following drawbacks: on the one hand, the drive structure for driving the lever, which consists of a rotating shaft, a swing block, a connecting block, a cylinder, etc., requires a relatively large installation space; on the other hand, the lever is driven by a rotating shaft, and the space required for the lever to swing is also relatively large; at the same time, the above-mentioned thread-shifting device is set outside the machine casing, which means that such a thread-shifting device will encroach on the sewing space at the sewing machine head, interfere with the sewing work of the sewing machine, and affect work efficiency. Utility Model Content

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a thread-pulling device for sewing machines. The technical problem this invention aims to solve is how to prevent the thread-pulling device from interfering with the sewing process.

[0006] The objective of this utility model can be achieved through the following technical solution: a thread-picking device for a sewing machine, the sewing machine including a machine housing, the thread-picking device including a lever, a driving component, and a transmission structure connecting the two, characterized in that the transmission structure is disposed within the machine housing and includes a sheet-shaped support plate, a sheet-shaped linkage plate, and a vertically arranged connecting rod, the support plate being parallel to the end face of the machine housing and fixedly connected within the machine housing, the linkage plate being stacked parallel to the support plate and hinged to the support plate, and being able to swing relative to the support plate under the drive of the driving component, the support plate having an arc-shaped hole, the linkage plate having a strip-shaped hole intersecting the arc-shaped hole, a pulley fixed on the connecting rod, the pulley being located within the strip-shaped hole and the arc-shaped hole and slidingly engaging with both, a guide structure being provided within the machine housing, the connecting rod being able to remain vertical during movement through the guide structure, the lower end of the connecting rod extending out of the machine housing and fixedly connected to the lever.

[0007] Unlike existing thread-picking devices that require excessive installation space and cannot be concealed within the machine housing, this invention improves upon the existing sewing machine housing structure by flattening the transmission structure of the thread-picking device. This allows the transmission structure to be concealed within the housing, thus preventing the thread-picking device from interfering with sewing operations. Specifically, due to the limited internal space of existing sewing machine housings, especially along the length, this invention designs the transmission structure to include a sheet-like support plate, a sheet-like linkage plate, and a vertically positioned connecting rod. The support plate is parallel to the end face of the housing, and the linkage plate is parallel to and hinged to the support plate. Both are sheet-like structures, and the vertically positioned connecting rod utilizes the vertical space of the housing. This design significantly reduces the installation space required for these transmission components along the length of the housing. Furthermore, by creating arc-shaped holes in the support plate and strip-shaped holes in the linkage plate, and then fixing pulleys to the connecting rod... The sliding cooperation between the two not only achieves the linkage design of the support plate, linkage plate, and connecting rod, but also utilizes the space of the support plate and linkage plate themselves, thus saving overall installation space. Furthermore, since the space in the width direction of the machine housing is also very limited, the design allows the connecting rod to maintain a vertical guiding structure during movement, thus transforming the overall movement of the connecting rod into an arc-shaped translational motion, ensuring that the connecting rod can move within the limited space of the machine housing. Therefore, through the above ingenious flattening design of the transmission structure, the installation space required for the transmission structure is greatly reduced, allowing the transmission structure to be hidden inside the machine housing, thereby avoiding interference with the sewing machine's sewing operations.

[0008] In the thread-picking device of the sewing machine described above, the guiding structure includes a guide seat fixed to a support plate, a guide shaft rotatably connected to the guide seat, and a guide hole penetrating the outer circumference of the guide shaft. The upper end of the connecting rod has a guide portion that is arc-shaped and bends in the opposite direction to the arc-shaped hole. The guide portion passes through the guide hole and slides in cooperation with it. Through this guide structure design, when the pulley carries the connecting rod along the arc-shaped hole, the sliding cooperation between the guide portion and the guide hole ensures that the connecting rod remains in its initial vertical state. This transforms the overall movement of the connecting rod into an arc-shaped translational motion, ensuring that the connecting rod can move within the limited space of the machine housing. Furthermore, it allows the transmission structure to be concealed within the machine housing, preventing the thread-picking device from interfering with the sewing operation.

[0009] In the thread-feeding device of the sewing machine described above, the two inner walls of the guide hole in the radial direction of the guide shaft are convex arc surfaces. This design allows the guide part to slide more smoothly within the guide hole, thus ensuring that the connecting rod remains stably vertical during movement.

[0010] In the thread-picking device of the sewing machine described above, the machine housing includes a main head housing and a cover located at one end of the main head housing. A sheet-like mounting plate is fixedly connected to the end face of the main head housing near the cover. The transmission structure is disposed between the mounting plate and the cover, and a support plate is fixed parallel to the mounting plate. This sheet-like mounting plate design facilitates the installation of the transmission structure without excessively occupying installation space along the length of the machine housing.

[0011] In the aforementioned thread-picking device of the sewing machine, the driving component is a cylinder or a linear motor. The driving component is fixed inside the machine housing. The drive shaft of the driving component is vertically downwards, and a vertically arranged connecting rod is provided between it and the linkage plate. The upper end of the connecting rod is fixedly connected to the drive shaft of the driving component, and the lower end is hinged to the linkage plate. By incorporating the driving component into the machine housing and using a vertical arrangement for both the driving component and the connecting rod, the relatively ample vertical space within the machine housing is utilized effectively, without requiring additional installation space. This allows the entire thread-picking device to be essentially completely concealed within the machine housing, further preventing interference with the sewing process.

[0012] In the thread-picking device of the sewing machine described above, the connecting rod includes an upper connecting rod and a lower connecting rod. The pulley is fixed to the upper connecting rod, and the upper end of the lower connecting rod has a vertically arranged strip-shaped hole. A screw passes through the strip-shaped hole, and the lower connecting rod is fixedly connected to the upper connecting rod by the screw. The lower end of the lower connecting rod is fixedly connected to the picking lever. Through the split design of the connecting rod and the strip-shaped hole, the overall length of the connecting rod is adjustable, thereby improving the applicability of this thread-picking device.

[0013] As an alternative, in the thread-picking device of the sewing machine described above, the guiding structure includes a guide groove on the machine housing. The guide groove is arc-shaped and its direction is consistent with the arc-shaped hole. A guide pin is fixed to the upper end of the connecting rod, and the guide pin slides in conjunction with the guide groove. Through this guide structure design, when the pulley carries the connecting rod along the arc-shaped hole, the sliding engagement of the guide pin and the guide groove ensures that the connecting rod remains in its initial vertical state. This transforms the overall movement of the connecting rod into an arc-shaped translational motion, thereby ensuring that the connecting rod can move within the limited space of the machine housing. Furthermore, this allows the transmission structure to be concealed within the machine housing, preventing the thread-picking device from interfering with the sewing operation.

[0014] Compared with existing technologies, the thread-picking device of this sewing machine has the following advantages: Through the ingenious design of flattening the transmission structure and making reasonable use of the vertical space inside the machine casing, the thread-picking device greatly reduces the installation space required for the thread-picking device, allowing the thread-picking device to be almost completely hidden inside the machine casing, thereby avoiding interference with the sewing operation of the sewing machine and improving the efficiency of the sewing operation. Attached Figure Description

[0015] Figure 1 This is an exploded structural diagram of the sewing machine in Embodiment 1.

[0016] Figure 2 This is a schematic diagram of the installation structure of the wire-pulling device in Embodiment 1. Figure 1 .

[0017] Figure 3 This is a schematic diagram of the installation structure of the wire-pulling device in Embodiment 1. Figure 2 .

[0018] Figure 4 This is an exploded structural diagram of the wire-pulling device in Embodiment 1.

[0019] Figure 5 This is a schematic diagram of the guide structure in this embodiment two.

[0020] In the diagram, 1. Housing; 1a. Main housing of the machine head; 1b. Cover; 1c. Guide groove; 2. Lever; 3. Drive component; 4. Support plate; 41. Arc-shaped hole; 5. Linkage plate; 51. Strip hole; 6. Connecting rod; 61. Upper connecting rod; 62. Lower connecting rod; 621. Strip vertical hole; 6a. Guide part; 6b. Guide pin; 7. Pulley; 8. Guide seat; 9. Guide shaft; 91. Guide hole; 10. Mounting plate; 11. Connecting rod; a. Transmission structure. 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] Specifically, such as Figure 1 As shown, the sewing machine includes a housing 1 and a thread-shifting device. The housing 1 includes a main head housing 1a and a cover 1b located at one end of the main head housing 1a. A sheet-like mounting plate 10 is fixedly connected to the end face of the main head housing 1a near the cover 1b. The thread-shifting device includes a lever 2, a drive component 3, and a transmission structure a that connects the two. The drive component 3 is a cylinder or a linear motor and is fixed inside the housing 1. The transmission structure a is disposed between the mounting plate 10 and the cover 1b, forming a flat mounting cavity. The transmission structure a is located within the mounting cavity. For example... Figure 2 and Figure 3 As shown, the transmission structure a includes a sheet-like support plate 4, a sheet-like linkage plate 5, and a vertically arranged connecting rod 6. The support plate 4 is parallel to the end face of the housing 1 and fixed on the mounting plate 10. The linkage plate 5 is stacked parallel to the support plate 4 and hinged to the support plate 4. The drive shaft of the drive member 3 is vertically downward and a vertically arranged connecting rod 11 is provided between it and the linkage plate 5. The upper end of the connecting rod 11 is fixedly connected to the drive shaft of the drive member 3, and the lower end is hinged to the linkage plate 5. The linkage plate 5 can swing relative to the support plate 4 under the drive of the drive member 3. The support plate 4 has an arc-shaped hole 41, and the linkage plate 5 has a strip-shaped hole 51 that intersects with the arc-shaped hole 41. A pulley 7 is fixed on the connecting rod 6. The pulley 7 is located in the strip-shaped hole 51 and the arc-shaped hole 41 and slides with both. The housing 1 has a guide structure. The connecting rod 6 can remain vertical during movement through the guide structure. The lower end of the connecting rod 6 extends out of the housing 1 and is fixedly connected to the lever 2.

[0024] More specifically, such as Figure 3 and Figure 4 As shown, in this embodiment, the guide structure includes a guide seat 8 fixed on the support plate 4, a guide shaft 9 rotatably connected to the guide seat 8, a guide hole 91 penetrating through the outer circumferential surface of the guide shaft 9, the two inner walls of the guide hole 91 in the radial direction of the guide shaft 9 being outwardly convex arc surfaces, and the upper end of the connecting rod 6 having a guide part 6a in the shape of an arc rod with a bending direction opposite to that of the arc hole 41, the guide part 6a penetrating the guide hole 91 and slidingly engaging with the guide hole 91.

[0025] In addition, in this embodiment, the connecting rod 6 adopts a split adjustable structure. The connecting rod 6 includes an upper connecting rod 61 and a lower connecting rod 62. The pulley 7 is fixed on the upper connecting rod 61, and the guide part 6a is located on the upper connecting rod 61. The upper end of the lower connecting rod 62 has a vertically arranged strip-shaped hole 621, and a screw passes through the strip-shaped hole 621. The lower connecting rod 62 is fixed to the upper connecting rod 61 by the screw, and the lower end of the lower connecting rod 62 is fixed to the lever 2.

[0026] The working principle of this wire-picking device is as follows: When a wire-picking action is required, the driving component 3 drives the connecting rod 11 to move upward. The connecting rod 11 will then drive the linkage plate 5 to swing downward relative to the support plate 4. At this time, the linkage plate 5 will exert force to drive the pulley 7 through the sliding cooperation between the strip hole 51 on it and the pulley 7, and make the pulley 7 slide downward along the arc hole 41 on the support plate 4. This causes the connecting rod 6 connected to the pulley 7 to also move downward in an arc. At the same time, the guide part 6a on the connecting rod 6 will slide in the guide hole 91, so that the upper end of the connecting rod 6 is guided and limited, ensuring that the connecting rod 6 remains vertical. Finally, the connecting rod 6 can make a vertical arc translation movement, thereby avoiding the connecting rod 6 tilting or swinging itself, which would cause the space occupied by the movement trajectory to expand, so that the connecting rod 6 can move within the small and limited space of the housing 1.

[0027] Example 2:

[0028] The technical solution in this embodiment is basically the same as that in Embodiment 1, except that, as Figure 5 As shown, in this embodiment, the guide structure includes a guide groove 1c provided on the housing 1. The guide groove 1c is arc-shaped and its direction is consistent with the arc-shaped hole 41. A guide pin 6b is fixed at the upper end of the connecting rod 6, and the guide pin 6b slides with the guide groove 1c.

[0029] 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.

[0030] Although this document frequently uses terms such as housing 1, main housing 1a, cover 1b, guide groove 1c, lever 2, drive component 3, support plate 4, arc-shaped hole 41, linkage plate 5, strip-shaped hole 51, connecting rod 6, upper connecting rod 61, lower connecting rod 62, strip-shaped vertical hole 621, guide part 6a, guide pin 6b, pulley 7, guide seat 8, guide shaft 9, guide hole 91, mounting plate 10, connecting rod 11, and transmission structure a, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any kind of additional limitation would contradict the spirit of this utility model.

Claims

1. A thread-picking device for a sewing machine, the sewing machine comprising a housing (1), the thread-picking device comprising a lever (2), a drive element (3), and a transmission structure (a) for drivingly connecting the two, characterized in that, The transmission structure (a) is set inside the housing (1) and includes a sheet-shaped support plate (4), a sheet-shaped linkage plate (5), and a vertically arranged connecting rod (6). The support plate (4) is parallel to the end face of the housing (1) and fixed inside the housing (1). The linkage plate (5) is stacked parallel to the support plate (4) and hinged to the support plate (4), and can swing relative to the support plate (4) under the drive of the driving member (3). An arc-shaped hole is provided on the support plate (4). (41) A strip hole (51) is provided on the linkage plate (5) and intersecting with the arc hole (41). A pulley (7) is fixed on the connecting rod (6). The pulley (7) is located in the strip hole (51) and the arc hole (41) and slides with both. A guide structure is provided in the housing (1). The connecting rod (6) can remain vertical during movement through the guide structure. The lower end of the connecting rod (6) extends out of the housing (1) and is fixedly connected to the lever (2).

2. The thread-feeding device of the sewing machine according to claim 1, characterized in that, The guide structure includes a guide seat (8) fixed on a support plate (4), a guide shaft (9) rotatably connected to the guide seat (8), a guide hole (91) is provided through the outer circumferential surface of the guide shaft (9), and the upper end of the connecting rod (6) has a guide part (6a) that is arc-shaped and the bending direction is opposite to that of the arc-shaped hole (41). The guide part (6a) passes through the guide hole (91) and slides with the guide hole (91).

3. The thread-picking device for a sewing machine according to claim 2, characterized in that, The two inner walls of the guide hole (91) in the radial direction of the guide shaft (9) are convex arc surfaces.

4. The thread-feeding device of a sewing machine according to claim 1, 2, or 3, characterized in that, The housing (1) includes a main housing (1a) and a cover (1b) located at one end of the main housing (1a). A sheet-shaped mounting plate (10) is fixedly connected to the end face of the main housing (1a) near the end of the cover (1b). The transmission structure (a) is disposed between the mounting plate (10) and the cover (1b). The support plate (4) is fixed parallel to the mounting plate (10).

5. The thread-feeding device of a sewing machine according to claim 1, 2, or 3, characterized in that, The driving component (3) is a cylinder or a linear motor. The driving component (3) is fixed inside the housing (1). The driving shaft of the driving component (3) is set vertically downward and a connecting rod (11) is arranged vertically between it and the linkage plate (5). The upper end of the connecting rod (11) is fixedly connected to the driving shaft of the driving component (3), and the lower end is hinged to the linkage plate (5).

6. The thread-feeding device of a sewing machine according to claim 1, 2, or 3, characterized in that, The connecting rod (6) includes an upper connecting rod (61) and a lower connecting rod (62). The pulley (7) is fixed on the upper connecting rod (61). The upper end of the lower connecting rod (62) has a vertically arranged strip hole (621). A screw passes through the strip hole (621). The lower connecting rod (62) is fixed to the upper connecting rod (61) by the screw. The lower end of the lower connecting rod (62) is fixed to the lever (2).

7. The thread-feeding device of the sewing machine according to claim 1, characterized in that, The guiding structure includes a guide groove (1c) provided on the housing (1). The guide groove (1c) is arc-shaped and its direction is consistent with the arc-shaped hole (41). The upper end of the connecting rod (6) is fixed with a guide pin (6b), and the guide pin (6b) slides with the guide groove (1c).

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