Cutting structure of sewing machine

Abstract

The utility model provides a kind of cutting structure of sewing machine belongs to sewing machine technical field.It solves the problem of low reliability of cutting structure in the cutting process of existing cutting structure.The cutting structure of this sewing machine, including base and the presser foot of being set in the upper of base, the rear end of base is equipped with the fixed knife platform located in the rear of presser foot, the movable knife bar of being able to swing up and down is rotatably connected on base, one end of movable knife bar is connected with movable knife that can be close to fixed knife platform, the rear end of presser foot is fixedly connected with the presser foot rear guard plate of being L-shaped, the lower surface of presser foot rear guard plate is close to base setting, and there is gap between lower surface and base, and the lower end of presser foot rear guard plate is close to fixed knife platform setting.The cutting structure of this sewing machine makes the fabric after sewing between existing presser foot and fixed knife platform can pass through the lower pressure limit of newly added presser foot rear guard plate, reduce the bulging of fabric, and then improve the reliability of cutting.

Description

Technical Field

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

[0002] After the sewing machine finishes sewing, the connecting thread between the sewing machine and the product needs to be cut with scissors. For overlock sewing machines, not only the connecting thread needs to be cut, but also the fabric being overlocked needs to be cut, making the cutting process more difficult.

[0003] Existing sewing machine cutting structures, such as the Chinese patent application [Authorization Announcement No.: CN206616349U], disclose a rear cutter thread trimming device for a sewing machine. A thread trimming step or groove is provided on the frame behind the needle plate. A fixed blade is installed on the side wall of the thread trimming step or groove. A blade bar is rotatably mounted on the frame on one side of the thread trimming step or groove, and a moving blade is mounted on the blade bar, which is close to the fixed blade. A drive mechanism is provided on the lower side of the frame to drive the blade bar to rotate. A crossbar is provided on the frame, and a drive mechanism is provided on the frame at the rear end of the crossbar. The drive mechanism drives the crossbar to perform a transverse reciprocating motion. A rack portion is provided at the front end of the crossbar, and the rack portion meshes with the end teeth at the rear of the blade bar.

[0004] The above structure uses a rack and toothed section to control the rotation of the cutter bar, which in turn drives the moving cutter to swing relative to the fixed cutter, thus cutting the connecting thread. However, during the sewing process, it is usually necessary to cut the fabric and the connecting thread simultaneously. The existing method simply uses the presser foot to hold the fabric in place, while the moving and fixed cutters are located at the rear end of the presser foot. This allows the sewn fabric to be fed to the rear end along with the needle plate and cut by the moving and fixed cutters. Since the fabric has a certain degree of elasticity, it is easy for it to return to its original position after detaching from the presser foot during the feeding process, which reduces the reliability of the cutting. Utility Model Content

[0005] The purpose of this utility model is to address the aforementioned problems in existing technologies by proposing a cutting structure for sewing machines. The technical problem to be solved by this utility model is: how to solve the problem of low reliability in cutting during the cutting process of existing cutting structures.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] A cutting structure for a sewing machine includes a machine base and a lifting presser foot disposed above the machine base. The rear end of the machine base is provided with a fixed blade table located behind the lifting presser foot. A movable blade rod capable of swinging up and down is rotatably connected to the machine base. One end of the movable blade rod is connected to a movable blade that can be pressed against the fixed blade table. The lifting presser foot is characterized in that an L-shaped presser foot rear guard plate is fixedly connected to the rear end of the lifting presser foot. The lower surface of the presser foot rear guard plate is disposed close to the machine base, and there is a gap between the lower surface and the machine base. The lower end of the presser foot rear guard plate is disposed near the fixed blade table.

[0008] When cutting the sewn fabric and connecting thread, the presser foot, in conjunction with the needle plate on the machine base, moves the sewn fabric and connecting thread backward. The moving blade and fixed blade holder are both located behind the presser foot. An L-shaped presser foot rear guard plate is fixed to the presser foot. When the presser foot moves, the presser foot rear guard plate moves synchronously with the presser foot, and the lower surface of the presser foot rear guard plate is set close to the machine base. This allows the sewn fabric to move from the gap between the lower surface of the presser foot rear guard plate and the machine base to the moving blade and fixed blade holder after sewing. The presser foot rear guard plate can press down and limit the sewn fabric. This allows the sewn fabric located between the existing presser foot and fixed blade holder to be reduced from bulging by the pressure limit of the newly added presser foot rear guard plate, thereby improving the reliability of cutting.

[0009] In the cutting structure of the sewing machine described above, the upper end of the presser foot rear guard plate is fixedly connected to the presser foot, and the lower end of the presser foot rear guard plate is inclined downward from front to back.

[0010] This design allows the presser foot back plate to exert greater pressure on the fabric as it gets closer to the fixed cutter table, further improving the reliability of cutting.

[0011] In the cutting structure of the sewing machine described above, a pressure seat is connected to the machine base and located above the fixed blade table. The pressure seat has at least one air blowing channel, and the outlet of the air blowing channel is set towards the fixed blade table.

[0012] By setting up a pressure seat and connecting an external air pump to the air blowing channel, the gas from the air blowing channel of the pressure seat will blow and press the sewn fabric close to the fixed blade table onto the fixed blade table during cutting, thereby improving the reliability of cutting.

[0013] In the cutting structure of the sewing machine described above, the pressure plate is Z-shaped, the fixed blade is located directly below the pressure plate, the pressure plate is located at the rear end of the presser foot guard plate, and an air blowing space is formed between the lower end face of the pressure plate and the fixed blade.

[0014] The shape of the pressure seat ensures that it does not affect the movement of the presser foot's rear guard plate, and it can also stably blow gas into the air blowing space, pressing the sewn fabric onto the fixed platform with the blown gas, further improving the stability of cutting.

[0015] In the cutting structure of the sewing machine described above, the lower end face of the pressure seat has a guide wall that is inclined toward the direction of the moving blade, and the outlet of the air blowing channel is opened on the guide wall.

[0016] This structure ensures that the outlet of the air blowing channel is directly opposite the cutting position, which facilitates blowing and pressing the fabric onto the fixed blade table, thereby improving the reliability of cutting.

[0017] In the cutting structure of the sewing machine described above, a driving component is fixedly connected to the machine base, a rack arranged laterally is fixedly connected to the drive shaft of the driving component, and the rear end of the moving cutter bar has a swing tooth, the rack meshing with the swing tooth.

[0018] The combination of the rack and pinion teeth makes the movement of the moving blade more stable and smooth, resulting in better cutting performance.

[0019] In the cutting structure of the sewing machine described above, a moving knife guide seat is connected to the machine base. The top surface of the moving knife guide seat is recessed to form a guide groove. The rack is rectangular and slidably connected in the guide groove. The swing tooth is located on the upper side of the rack. The driving component is fixed on the moving knife guide seat.

[0020] The cooperation between the guide groove and the rack makes the drive component more stable when pushing the rack, so that the moving cutter bar can only move laterally back and forth, and cannot deviate in the forward and backward directions, thus ensuring that the moving cutter is close to the fixed cutter table and ensuring the stability of cutting.

[0021] Compared with the prior art, the present invention has the following advantages: After sewing, the fabric moves from the gap between the lower surface of the presser foot rear guard plate and the machine base to the moving knife and the fixed knife table. The presser foot rear guard plate can press down and limit the sewn fabric, so that the sewn fabric located between the existing presser foot and the fixed knife table can be reduced by the pressure limit of the newly added presser foot rear guard plate, thereby improving the reliability of cutting. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the assembled structure of this utility model.

[0023] Figure 2 This is a structural schematic diagram of the present invention from another direction after assembly.

[0024] Figure 3 This is a partial side view of the assembled version of this utility model.

[0025] Figure 4 This is a schematic diagram of the structure of the pressure foot rear guard plate in this utility model.

[0026] Figure 5 This is a schematic diagram of the structure of the pressure material holder in this utility model.

[0027] Figure 6 This is a vertical sectional view of the pressure seat in this utility model.

[0028] In the diagram, 1 is the machine base; 11 is the fixed knife table; 2 is the lifting pressure foot; 3 is the moving knife rod; 31 is the moving knife; 32 is the swing tooth; 4 is the pressure foot rear guard plate; 5 is the clearance; 6 is the pressure seat; 61 is the air blowing channel; 61a is the outlet; 62 is the guide wall; 7 is the air blowing space; 8 is the driving component; 81 is the drive shaft; 82 is the rack; 9 is the moving knife guide seat; 91 is the guide groove. Detailed Implementation

[0029] 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.

[0030] like Figure 2 As shown, the cutting structure of this sewing machine includes a base 1 and a lifting presser foot 2 located above the base 1. The rear end of the base 1 is provided with a fixed blade table 11 located behind the lifting presser foot 2. A movable blade rod 3 that can swing up and down is rotatably connected to the base 1. One end of the movable blade rod 3 is connected to a movable blade 31 that can be pressed against the fixed blade table 11.

[0031] Specifically, such as Figure 1-3 As shown, an L-shaped rear guard plate 4 is fixedly connected to the rear end of the lifting presser foot 2. The lower surface of the rear guard plate 4 is close to the machine base 1, and there is a gap 5 between the lower surface and the machine base 1. The lower end of the rear guard plate 4 is close to the fixed tool table 11. The upper end of the rear guard plate 4 is fixedly connected to the lifting presser foot 2. The lower end of the rear guard plate 4 is inclined downward from front to back.

[0032] When it is necessary to cut the sewn fabric and connecting thread, the presser foot 2, in conjunction with the needle plate on the machine base 1, moves the sewn fabric and connecting thread backward. The moving blade 31 and the fixed blade holder are both located behind the presser foot 2. An L-shaped presser foot rear guard plate 4 is fixed on the presser foot 2. When the presser foot 2 moves, the presser foot rear guard plate 4 moves synchronously with the presser foot 2. The lower surface of the presser foot rear guard plate 4 is set close to the machine base 1, so that the sewn fabric moves from the gap 5 between the lower surface of the presser foot rear guard plate 4 and the machine base 1 to the moving blade 31 and the fixed blade holder 11 after sewing. The presser foot rear guard plate 4 can press down and limit the sewn fabric, so that the sewn fabric located between the existing presser foot 2 and the fixed blade holder 11 can be reduced by the downward pressure of the newly added presser foot rear guard plate 4, thereby improving the reliability of cutting.

[0033] like Figure 3-6As shown, a pressure seat 6 is connected to the base 1 and located above the fixed knife table 11. The pressure seat 6 has at least one air blowing channel 61. The outlet 61a of the air blowing channel 61 is set towards the fixed knife table 11. The pressure seat 6 is Z-shaped. The fixed knife table 11 is located directly below the pressure seat 6. The pressure seat 6 is located at the rear end of the pressure foot rear guard plate 4. An air blowing space 7 is formed between the lower end face of the pressure seat 6 and the fixed knife table 11. The lower end face of the pressure seat 6 has a guide wall 62 that is inclined towards the moving knife 31. The outlet 61a of the air blowing channel 61 is opened on the guide wall 62.

[0034] like Figure 1 and Figure 2 As shown, a drive unit 8 is fixedly connected to the base 1. A rack 82 arranged in a transverse direction is fixedly connected to the drive shaft 81 of the drive unit 8. The rear end of the moving tool bar 3 has a swing tooth 32. The rack 82 meshes with the swing tooth 32. A moving tool guide seat 9 is connected to the base 1. The top surface of the moving tool guide seat 9 is recessed to form a guide groove 91. The rack 82 is rectangular and slidably connected in the guide groove 91. The swing tooth 32 is located on the upper side of the rack 82. The drive unit 8 is fixed on the moving tool guide seat 9.

[0035] 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 cutting structure for a sewing machine, comprising a machine base (1) and a lifting presser foot (2) disposed above the machine base (1), wherein a fixed blade table (11) is provided at the rear end of the machine base (1) behind the lifting presser foot (2), and a movable blade rod (3) rotatably connected to the machine base (1) is capable of swinging up and down, one end of the movable blade rod (3) being connected to a movable blade (31) capable of adhering to the fixed blade table (11), characterized in that, The rear end of the lifting foot (2) is fixedly connected to an L-shaped press foot rear guard plate (4). The lower surface of the press foot rear guard plate (4) is close to the machine base (1), and there is a gap (5) between the lower surface and the machine base (1). The lower end of the press foot rear guard plate (4) is close to the fixed tool table (11).

2. The material cutting structure of the sewing machine according to claim 1, characterized in that, The upper end of the presser foot rear guard plate (4) is fixedly connected to the presser foot (2), and the lower end of the presser foot rear guard plate (4) is inclined downward from front to back.

3. The material cutting structure of the sewing machine according to claim 1 or 2, characterized in that, The base (1) is connected to a pressure seat (6) located above the fixed knife table (11). The pressure seat (6) is provided with at least one air blowing channel (61), and the outlet (61a) of the air blowing channel (61) is set towards the fixed knife table (11).

4. The material cutting structure of the sewing machine according to claim 3, characterized in that, The pressure seat (6) is Z-shaped, the fixed knife table (11) is located directly below the pressure seat (6), the pressure seat (6) is located at the rear end of the pressure foot rear guard plate (4), and an air blowing space (7) is formed between the lower end face of the pressure seat (6) and the fixed knife table (11).

5. The material cutting structure of the sewing machine according to claim 3, characterized in that, The lower end face of the pressure seat (6) has a guide wall (62) inclined toward the moving knife (31), and the outlet (61a) of the air blowing channel (61) is opened on the guide wall (62).

6. The material cutting structure of the sewing machine according to claim 1 or 2, characterized in that, A drive member (8) is fixedly connected to the base (1), and a rack (82) arranged in a transverse direction is fixedly connected to the drive shaft (81) of the drive member (8). The rear end of the moving tool bar (3) has a swing tooth (32), and the rack (82) meshes with the swing tooth (32).

7. The material cutting structure of the sewing machine according to claim 6, characterized in that, The base (1) is connected to a moving tool guide seat (9). The top surface of the moving tool guide seat (9) is recessed to form a guide groove (91). The rack (82) is rectangular and slidably connected in the guide groove (91). The swing tooth (32) is located on the upper side of the rack (82). The drive member (8) is fixed on the moving tool guide seat (9).

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