Thread trimming mechanism and sewing machine

Abstract

The utility model provides a kind of thread trimming mechanism and sewing machine, belong to sewing equipment technical field.The thread trimming mechanism includes mounting seat, mounting seat is provided with rotatable dynamic cutter one and dynamic cutter two, dynamic cutter one has recess, dynamic cutter two has the line-pressing portion extending outward, and the line-pressing portion can be abutted with the groove wall of recess.The thread trimming mechanism in the process of dynamic cutter one and dynamic cutter two thread trimming, dynamic cutter one and dynamic cutter two can press line, prevent thread breakage when sewing, press line and complete thread trimming in the case of simplifying structure.

Description

Technical Field

[0001] This utility model belongs to the field of sewing equipment technology, and relates to a thread-cutting mechanism and a sewing machine. Background Technology

[0002] The thread-cutting mechanism of existing sewing machines generally consists of a fixed blade, a moving blade, a connecting rod, and a drive shaft. The fixed blade is fixedly mounted on the machine housing, and the moving blade is mounted on the moving blade holder. The drive shaft drives the connecting rod, which in turn drives the moving blade holder, causing the moving blade to move toward the fixed blade to cut the thread.

[0003] Some thread-cutting mechanisms include two moving blades and a driving component that can rotate in opposite directions. For example, the thread-cutting mechanism of a sewing machine provided in patent document with application number 201710451937.4, in which the thread-cutting mechanism drives the linkage mechanism by swinging the thread-cutting drive shaft, thereby realizing the engagement of the active blade and the auxiliary blade and completing the thread-cutting action.

[0004] After a sewing machine begins sewing (the initial stitch), the loose threads on the fabric need to be trimmed; otherwise, bird's nests (where the threads wrinkle and bunch together, forming a clump) can easily form. After the initial stitch, the thread needs to be held down; if it's not, it can easily be pulled out by the needle, causing fraying. To prevent fraying, an additional pressing structure is often used to tighten the thread at the initial stitch, making the sewing machine's structure more complex. Summary of the Invention

[0005] This utility model addresses the aforementioned problems in the existing technology by providing a wire-cutting mechanism. The technical problem this utility model aims to solve is: how to perform wire pressing.

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

[0007] A wire cutting mechanism includes a mounting base on which two rotatable movable blades, namely a first movable blade and a second movable blade, are mounted. The first movable blade has a groove, and the second movable blade has an outwardly extending pressing portion that abuts against the groove wall.

[0008] Its working principle is as follows: During operation, the motor drives the first and second moving blades to rotate in opposite directions. After the machine needle sews the first stitch on the fabric, when the pressing part on the second moving blade abuts against the groove wall, the pressing part presses the thread end tightly onto the groove. Then the machine needle sews another stitch on the fabric. After that, the motor drives the first and second moving blades to continue rotating and interlocking, and the first and second moving blades cut the thread end. Then the motor drives the first and second moving blades to rotate in opposite directions, and the first and second moving blades gradually separate. At this time, the pressing part gradually detaches from the groove wall. At this point, two to three stitches have been sewn on the fabric. The pressing part no longer needs to press the thread down, and the thread will not come loose, so normal sewing can be carried out.

[0009] In this thread-cutting mechanism, the thread-pressing part and the groove form a thread-pressing structure. The thread-pressing part and the groove are respectively set on the second moving blade and the first moving blade. During the process of the second moving blade cutting the thread end, the first moving blade and the second moving blade can press the thread down themselves to prevent the thread from coming off when starting to sew. There is no need to set up additional thread-pressing plates or other structures. The thread pressing and cutting are completed with a simplified structure.

[0010] In the above-mentioned wire cutting mechanism, the outer end of the moving blade has an inclined guide surface, and the outer end of the pressing part can contact the guide surface.

[0011] When the first moving blade rotates towards the second moving blade, the pressing part first contacts the guide surface of the first moving blade. The guide surface is set at an angle, which plays a guiding role, so that the first moving blade and the second moving blade can make better contact and cooperate.

[0012] In the aforementioned wire-cutting mechanism, the wire-pressing part is elongated and extends towards the moving blade.

[0013] The elongated, strip-shaped creasing section saves material and easily produces slight elastic deformation, elastically pressing the thread for better creasing.

[0014] In the above-mentioned wire cutting mechanism, the outer side of the groove wall is arc-shaped, and the wire pressing part can abut against the outer side of the groove wall.

[0015] The connection between the groove wall and the second moving blade is smoothly transitioned by an arc. When the pressing part abuts against the outer side of the groove wall, it can press the line. When the first moving blade continues to rotate, the pressing part slides on the first moving blade without interference, allowing the first moving blade to continue rotating smoothly and complete the line cutting smoothly.

[0016] In the above-mentioned wire cutting mechanism, the moving blade is provided with a first wire-passing hole and a second wire-passing hole, and the groove is located between the first wire-passing hole and the second wire-passing hole.

[0017] The first and second thread holes are used for the needle to pass through. When the first thread hole is opposite to the needle, the needle sews one or two stitches on the fabric. The moving blade continues to rotate. When the second thread hole is opposite to the needle, the needle sews another stitch on the fabric. During the thread cutting process, the needle is ensured to sew the fabric smoothly.

[0018] In the above-mentioned wire cutting mechanism, the groove is provided on the outer side of the first moving blade, and the wire pressing part is provided on the outer side of the second moving blade.

[0019] In the above-mentioned wire cutting mechanism, the mounting base is provided with a rotating ring and a mounting plate, both of which are rotatable. The first moving blade is mounted on the edge of the rotating ring, and the second moving blade is mounted on the edge of the mounting plate.

[0020] The rotating ring and mounting plate are driven to rotate by a motor and linkage mechanism. The first moving blade rotates with the rotating ring, and the second moving blade rotates with the mounting plate. When the first moving blade and the second moving blade mesh, the wire pressing and cutting are completed.

[0021] This utility model also provides a sewing machine, which includes a worktable on which any of the above-mentioned thread-cutting mechanisms are installed.

[0022] Compared with the prior art, the advantages of this utility model are as follows:

[0023] In this thread-cutting mechanism, the pressing part and the groove are respectively set on the second moving blade and the first moving blade. During the process of the first moving blade and the second moving blade cutting the thread end, the first moving blade and the second moving blade can press the thread to prevent the thread from coming off when starting to sew. The pressing and cutting of the thread are completed with a simplified structure. The structure is simple and does not require the addition of other extra parts. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the wire-cutting mechanism installed on the workbench;

[0025] Figure 2 This is a schematic diagram of the wire-cutting mechanism;

[0026] Figure 3 This is a structural schematic diagram of the moving blade;

[0027] Figure 4 This is a schematic diagram of the second moving blade.

[0028] In the diagram: 1 Mounting base, 2 Moving blade 2, 3 Moving blade 1, 4 Groove, 5 Wire pressing part, 6 Guide surface, 7 Wire through hole 1, 8 Wire through hole 2, 9 Mounting plate, 10 Rotary ring, 11 Worktable, 12 Motor, 13 Linkage mechanism. Detailed Implementation

[0029] The following are specific embodiments of the present invention, and the technical solution of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0030] like Figure 2-4 As shown, the wire cutting mechanism includes a mounting base 1, on which are mounted a first movable blade 3 and a second movable blade 2, both of which are rotatable. The first movable blade 3 has a groove 4, and the second movable blade 2 has an outwardly extending pressing part 5, which can abut against the groove wall of the groove 4.

[0031] During operation, motor 12 drives moving blade 3 and moving blade 2 to rotate in opposite directions. After the machine needle sews the first stitch on the fabric, when the pressing part 5 on moving blade 2 comes into contact with the groove wall of the groove 4, the pressing part 5 presses the thread end tightly onto the groove 4. Then the machine needle sews another stitch on the fabric. After that, motor 12 drives moving blade 3 and moving blade 2 to continue rotating and engage with moving blade 2. Moving blade 3 and moving blade 2 cut the thread end. Then motor 12 drives moving blade 3 and moving blade 2 to rotate in opposite directions, and moving blade 3 and moving blade 2 gradually separate. At this time, the pressing part 5 gradually detaches from the groove wall of the groove 4. At this point, two to three stitches have been sewn on the fabric. The pressing part 5 no longer needs to press the thread and will not come loose, so normal sewing can be carried out.

[0032] like Figure 3 As shown, in this embodiment, the outer end of the moving blade 3 has an inclined guide surface 6, and the outer end of the pressing part 5 can contact the guide surface 6.

[0033] When the first moving blade 3 rotates toward the second moving blade 2, the pressing part 5 first contacts the guide surface 6 of the first moving blade 3. The guide surface 6 is set at an angle, which plays a guiding role, so that the first moving blade 3 and the second moving blade 2 can make better contact and cooperate.

[0034] like Figure 4 As shown, in this embodiment, the pressure part 5 is elongated and extends toward the moving blade 3.

[0035] The elongated pressing section 5 saves materials and easily produces slight elastic deformation, which elastically presses the thread for better pressing.

[0036] like Figure 3 As shown, in this embodiment, the outer side of the groove wall of the groove 4 is arc-shaped, and the pressure part 5 can abut against the outer side of the groove wall of the groove 4.

[0037] The connection between the groove wall of the groove 4 and the moving blade 2 is smoothly transitioned by an arc. When the pressing part 5 abuts against the outer side of the groove wall of the groove 4, it can press the line. When the moving blade 3 continues to rotate, the pressing part 5 slides on the moving blade 3 without interference, so that the moving blade 3 can continue to rotate smoothly and complete the line cutting smoothly.

[0038] like Figure 3 As shown, in this embodiment, the moving blade 3 is provided with a wire-passing hole 7 and a wire-passing hole 8, and the groove 4 is located between the wire-passing hole 7 and the wire-passing hole 8.

[0039] Thread guide hole 7 and thread guide hole 8 are used for the needle to pass through. When thread guide hole 7 is opposite to the needle, the needle sews one or two stitches on the fabric. The moving knife 3 continues to rotate. When thread guide hole 8 is opposite to the needle, the needle sews another stitch on the fabric. During the thread cutting process, the needle is ensured to sew the fabric smoothly.

[0040] like Figure 3 and 4 As shown, in this embodiment, the groove 4 is provided on the outer side of the moving blade 3, and the pressing part 5 is provided on the outer side of the moving blade 2.

[0041] like Figure 2 As shown, in this embodiment, the mounting base 1 is provided with a rotating ring 10 and a mounting plate 9, both of which are rotatable. The first moving blade 3 is mounted on the edge of the rotating ring 10, and the second moving blade 2 is mounted on the edge of the mounting plate 9.

[0042] The rotating ring 10 and the mounting plate 9 are driven to rotate by the motor 12 and the linkage mechanism 13. The first moving blade 3 rotates with the rotating ring 10, and the second moving blade 2 rotates with the mounting plate 9. When the first moving blade 3 and the second moving blade 2 mesh, the wire pressing and cutting are completed.

[0043] like Figure 1 As shown, this utility model also provides a sewing machine, which includes a worktable 11 on which any of the above-mentioned thread-cutting mechanisms are installed.

[0044] 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 wire-cutting mechanism, the wire-cutting mechanism comprising a mounting base (1), wherein the mounting base (1) is provided with a rotatable moving blade one (3) and a moving blade two (2), characterized in that, The first moving blade (3) has a groove (4), and the second moving blade (2) has an outwardly extending pressing part (5), which can abut against the groove wall of the groove (4).

2. The wire-cutting mechanism according to claim 1, characterized in that, The outer end of the moving blade (3) has an inclined guide surface (6), and the outer end of the pressing part (5) can contact the guide surface (6).

3. The wire-cutting mechanism according to claim 1, characterized in that, The pressure part (5) is elongated and extends toward the moving knife (3).

4. A wire-cutting mechanism according to claim 1, characterized in that, The outer side of the groove wall of the groove (4) is arc-shaped, and the pressure part (5) can abut against the outer side of the groove wall of the groove (4).

5. A wire-cutting mechanism according to claim 1, 2, 3, or 4, characterized in that, The moving blade (3) is provided with a wire hole (7) and a wire hole (8), and the groove (4) is located between the wire hole (7) and the wire hole (8).

6. A wire-cutting mechanism according to claim 1, 2, 3, or 4, characterized in that, The groove (4) is located on the outer side of the first moving blade (3), and the pressing part (5) is located on the outer side of the second moving blade (2).

7. A wire-cutting mechanism according to claim 1 or 2, characterized in that, The mounting base (1) is provided with a rotating ring (10) and a mounting plate (9), both of which are rotatable. The first moving blade (3) is mounted on the edge of the rotating ring (10), and the second moving blade (2) is mounted on the edge of the mounting plate (9).

8. A sewing machine, the sewing machine comprising a worktable (11), characterized in that, The workbench (11) is equipped with a wire-cutting mechanism as described in any one of claims 1-7.

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