Thread trimming mechanism of sewing machine

Abstract

The utility model relates to the technical field of sewing machines, in particular to a thread trimming mechanism of a sewing machine, which comprises a thread trimming box arranged on a machine head of the sewing machine, a thread trimming cavity with an opening at the lower end is arranged in the thread trimming box along the height direction of the thread trimming box, a liftable cutter body is arranged in the thread trimming cavity, and the cutter body can extend out of the thread trimming cavity and move towards a sewing needle to cut a sewing thread. A driving assembly used for driving the cutter body to stretch out for cutting is arranged in the thread trimming cavity, and the thread trimming box is installed on a sewing machine head through a connecting assembly. By means of the structure, when an existing thread trimming structure fails, the cutter body can stretch out of the opening of the thread trimming cavity and move towards the thread, so that the thread is cut off, the existing thread trimming structure can be overhauled subsequently, and after thread trimming operation is completed, the driving assembly can drive the cutter body to reset so that the cutter body can be reused subsequently. Compared with an existing operation mode that tools such as scissors are used for trimming threads, the thread trimming mechanism is simple and convenient to trim the threads.

Description

Technical Field

[0001] The utility model relates to the technical field of sewing machines, and specifically, to a thread cutting mechanism of a sewing machine. Background Art

[0002] A sewing machine is a machine that forms one or more stitches on a sewing material with one or more sewing threads to interweave or sew together one or more layers of sewing materials. Currently, a thread cutting mechanism is configured in a sewing machine to cut the sewing threads (including the upper thread and the bobbin thread) after sewing.

[0003] The thread cutting structure of the existing sewing machine includes a movable knife and a fixed knife located below the needle plate and above the rotary hook. The fixed knife is fixed on the sewing machine base, and the movable knife is driven by a driving mechanism to rotate around the lower shaft, and the sewing threads are cut by the engagement of the movable knife and the fixed knife.

[0004] After the sewing machine is used for a long time, the movable knife and the fixed knife will be worn, which will affect their cutting of the sewing threads. At this time, the user needs to manually cut the sewing threads between the sewing needle and the sewing material with tools such as scissors for subsequent maintenance of the movable knife and the fixed knife. The method of manually cutting with scissors requires the user to find tools such as scissors, which is rather inconvenient and thus needs to be improved. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a thread cutting mechanism of a sewing machine to solve the problems raised in the above background art.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] A thread cutting mechanism of a sewing machine includes a thread cutting box arranged on the sewing machine head. A thread cutting cavity with an open lower end is arranged in the thread cutting box along its height direction. A knife body that can be lifted and lowered is arranged in the thread cutting cavity. The knife body can extend out of the thread cutting cavity and move towards the sewing needle to cut the sewing threads. A driving component for driving the knife body to extend out for cutting is arranged in the thread cutting cavity. The thread cutting box is installed on the sewing machine head through a connecting component.

[0008] Preferably, the driving component includes a moving plate that can be lifted and lowered in the thread cutting cavity. A positioning plate penetrating the moving plate is arranged on the top wall of the thread cutting cavity. The knife body is movably arranged on the moving plate through a sliding plate. A guiding groove is arranged on the positioning plate, and a sliding rod located in the guiding groove and sliding therein is arranged on the sliding plate. The lifting of the moving plate is used to drive the sliding rod to slide along the guiding groove, driving the sliding plate to drive the knife body to extend out of the thread cutting cavity and move towards the sewing threads to cut them.

[0009] Preferably, an electric push rod for driving the moving plate to lift and lower is arranged on the top wall of the thread cutting cavity.

[0010] Preferably, sliders are oppositely provided on the bottom side surface of the moving plate along the moving direction of the sliding plate, and sliding grooves are provided on the sliding plate for sliding on the corresponding sliders.

[0011] Preferably, a connecting groove is provided at the lower end surface of the sewing machine head; a connecting portion extending into the connecting groove is provided on the thread trimming box, and a connecting hole is provided on the connecting portion; an installation groove communicating with the connecting groove is provided on one side of the sewing machine head, the connecting assembly includes a connecting shell arranged in the installation groove, a connecting cavity with one end open is arranged in the connecting shell, a plug ring is threadedly connected at the opening of the connecting cavity, a moving plate fitting with the inner wall thereof is further arranged in the connecting cavity, a guide rod extending out of the connecting cavity through the plug ring is arranged on one side of the moving plate, a spring is sleeved on the guide rod, and a connecting rod capable of extending into the connecting hole is arranged on the other side of the moving plate.

[0012] Preferably, a holding rod is provided at the extending end of the guide rod.

[0013] Preferably, holding grooves are oppositely provided on one end surface of the plug ring.

[0014] Preferably, a step groove is provided at the opening of the connecting groove, and a convex platform portion lapped in the step groove is provided on the connecting shell.

[0015] Preferably, a step groove is provided at the opening of the connecting groove, and a convex platform portion extending into the step groove is provided on the connecting shell.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] 1. In the present utility model, through the liftable setting of the cutter body in the thread trimming cavity, when the existing thread trimming structure fails, the cutter body can be extended from the lower end opening of the thread trimming cavity, and the cutter body can be moved towards the sewing thread, so as to cut the sewing thread, so as to facilitate the subsequent maintenance of the existing thread trimming structure. After the thread trimming operation is completed, the driving assembly can drive the cutter body to reset, so that it can be located in the thread trimming cavity for subsequent reuse. Compared with the existing method of using tools such as scissors for thread trimming operation, the thread trimming mechanism in the present utility model is simple and convenient for cutting the sewing thread.

[0018] 2. In the present utility model, through the setting of the connecting assembly, the thread trimming mechanism can be quickly disassembled and assembled on the sewing machine head, which is beneficial to actual use. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of a thread trimming mechanism for a sewing machine in the present utility model.

[0020] Figure 2 It is a schematic diagram of the structure of the sewing machine head and the second thread trimming assembly in the present utility model.

[0021] Figure 3This is a schematic structural diagram of an exploded view of a partial sewing machine head and a thread cutting box in the present utility model.

[0022] Figure 4 This is a schematic structural diagram of an electric push rod, a guide rod, and a sliding plate in the present utility model after removing a part of the thread cutting box.

[0023] Figure 5 This is a schematic structural diagram of the guide rod and the sliding plate from another perspective in the present utility model after removing a part of the thread cutting box.

[0024] Figure 6 This is an exploded view of a partial sewing machine head and a connection shell in the present utility model.

[0025] Figure 7 This is a schematic sectional view of the connection shell in the present utility model

[0026] The meanings of the reference numerals in the figure are as follows:

[0027] 100, workbench; 101, leg; 110, sewing machine head;

[0028] 200, sewing needle; 210, thread cutting box; 220, connection shell;

[0029] 300, connection groove; 310, connection part; 311, connection hole; 320, thread cutting cavity;

[0030] 400, moving plate; 401, slider; 410, sliding plate; 412, cutter body; 420, electric push rod; 430, positioning plate; 431, guide groove; 440, connection block; 441, sliding rod;

[0031] 500, moving groove;

[0032] 600, installation groove; 610, step groove; 620, plug ring; 621, holding groove; 630, convex part; 640, holding rod;

[0033] 700, connection cavity; 710, moving circular plate; 711, connecting rod; 720, guide rod; 730, spring. Detailed implementation manners

[0034] To further understand the content of the present utility model, the present utility model will be described in detail in combination with the accompanying drawings and embodiments. It should be understood that the embodiments are only for explaining the present utility model and not for limiting it.

[0035] The following combines the attached Figures 1-7 This embodiment will be further described in detail.

[0036] Please refer to Figures 1-3, A thread cutting mechanism in this embodiment includes a thread cutting box 210 provided on a sewing machine head 110. A thread cutting cavity 320 with an open lower end is provided in the thread cutting box 210 along its height direction. A liftable cutter body 412 is provided in the thread cutting cavity 320. The cutter body 412 can extend out of the thread cutting cavity 320 and move towards the sewing needle 200 to cut the sewing thread. A driving assembly for driving the cutter body 412 to extend and cut is provided in the thread cutting cavity 320. The thread cutting box 210 is installed on the sewing machine head 110 through a connecting assembly.

[0037] In this embodiment, the sewing machine head 110 is of an existing structure. It is arranged on a workbench 100. A thread cutting structure is arranged in the workbench 100 at a position below the sewing machine head 110. This thread cutting structure can adopt the structure disclosed in Chinese Patent No. CN109234928B, which can cut the sewing thread. The thread cutting mechanism in this embodiment can cut the sewing thread between the sewing needle 200 and the sewing material on the workbench 100 when the thread cutting structure fails, so as to perform subsequent maintenance and repair on the failed thread cutting structure;

[0038] Among them, legs 101 are relatively provided at the four corners at the bottom of the workbench 100, and the legs 101 can support the workbench 100;

[0039] Among them, through the liftable setting of the cutter body 412 in the thread cutting cavity 320, when thread cutting operation is required, the cutter body 412 can be extended from the lower end opening of the thread cutting cavity 320, and the cutter body 412 can be moved towards the sewing thread to cut the sewing thread. After the thread cutting operation is completed, the driving assembly can drive the cutter body 412 to reset so that it can be located in the thread cutting cavity 320 for subsequent reuse;

[0040] Among them, through the setting of the connecting assembly, the disassembly and assembly of this thread cutting mechanism on the sewing machine head 110 can be carried out quickly.

[0041] As Figures 3-5 shown, in this embodiment, the driving assembly includes a moving plate 400 that is liftably arranged in the thread cutting cavity 320. A positioning plate 430 penetrating the moving plate 400 is provided on the top wall of the thread cutting cavity 320. The cutter body 412 is movably arranged on the moving plate 400 through a sliding plate 410. A guiding groove 431 is provided on the positioning plate 430. A sliding rod 441 located in the guiding groove 431 is provided on the sliding plate 410. The lifting of the moving plate 400 is used to drive the sliding rod 441 to slide along the guiding groove 431, driving the sliding plate 410 to drive the cutter body 412 to extend out of the thread cutting cavity 320 and move towards the sewing thread to cut it.

[0042] In this embodiment, as Figure 4As shown, an electric push rod 420 for driving the lifting of the moving plate 400 is provided on the top wall of the wire cutting cavity 320. The electric push rod 420 is used to drive the sliding plate 410 to move towards the opening direction of the wire cutting cavity 320, so that the sliding rod 441 slides in the guiding groove 431, and then the cutter body 412 extends out of the wire cutting cavity 320 and moves towards the sewing thread, so that the sewing thread is cut off;

[0043] As Figure 4 and Figure 5 shown, the guiding groove 431 includes a vertical groove and an inclined groove arranged along the length direction of the positioning plate 430. The upper end of the inclined groove is communicated with the lower end of the vertical groove. At the same time, the sliding plate 410 is fixedly connected to the sliding rod 441 through a connecting block 440. A moving groove 500 for the connecting block 440 to penetrate is arranged on the moving plate 400 along the sliding direction of the sliding plate 410. Thus, when the sliding rod 441 slides downward from the vertical groove, it can drive the connecting block 440, the sliding plate 410 and the cutter body 412 to extend out of the opening of the wire cutting cavity 320. At this time, when the moving plate 400 continues to move downward and the sliding rod 441 slides from the vertical groove into the inclined groove, it can drive the connecting block 440, the sliding plate 410 and the cutter body 412 to move towards the sewing thread, and finally the cutter body 412 can cut off the sewing thread; Thus, the cutting of the sewing thread is completed. Compared with the existing manual wire cutting, the wire cutting in this embodiment is more convenient; after the wire cutting is completed, the electric push rod 420 drives the moving plate 400 to reset, and the sliding plate 410 and the cutter body 412 can be retracted into the wire cutting cavity 320, which is convenient for the next wire cutting operation;

[0044] As Figure 4 shown, in this embodiment, sliding blocks 401 are relatively arranged on the bottom side surface of the moving plate 400 along the moving direction of the sliding plate 410, and sliding grooves for sliding on the corresponding sliding blocks 401 are arranged on the sliding plate 410.

[0045] In this embodiment, the sliding block 401 is in an I shape, and the sliding groove can be clamped therein. Thus, the sliding installation of the sliding plate 410 on the lower side surface of the moving plate 400 is realized.

[0046] As Figures 1-7As shown, in this embodiment, a connection groove 300 is provided at the lower end surface of the sewing machine head 110. A connection portion 310 extending into the corresponding connection groove 300 is provided on the thread trimming box 210. A connection hole 311 is provided on the connection portion 310. An installation groove 600 communicating with the connection groove 300 is provided on one side of the sewing machine head 110. The connection assembly includes a connection shell 220 provided in the installation groove 600. A connection cavity 700 with one end open is provided in the connection shell 220. A plug ring 620 is threadedly connected to the opening of the connection cavity 700. A moving circular plate 710 fitting against the inner wall of the connection cavity 700 is further provided in the connection cavity 700. A guide rod 720 passing through the plug ring 620 and extending out of the connection cavity 700 is provided on one side of the moving circular plate 710. A spring 730 is sleeved on the guide rod 720. A connecting rod 711 that can extend into the connection hole 311 is provided on the other side of the moving circular plate 710.

[0047] In this embodiment, when the thread trimming box 210 and the sewing machine head 110 need to be connected, first, pull the guide rod 720 to drive the moving circular plate 710 to compress the spring 730, so that the connecting rod 711 retracts into the connection cavity 700. Insert the connection portion 310 into the connection groove 300. Release the guide rod 720. Under the thrust of the spring 730, the moving circular plate 710 and the connecting rod 711 move towards the direction close to the connection portion 310, and the connecting rod 711 extends into the connection hole 311 to complete the connection between the thread trimming box 210 and the sewing machine head 110. When the connection between the thread trimming box 210 and the sewing machine head 110 needs to be released, pull the guide rod 720 to make the connecting rod 711 retract into the connection cavity 700, and then the thread trimming box 210 can be removed. This process is relatively rapid and efficient.

[0048] Among them, during assembly, first place the connecting rod 711, the moving circular plate 710 and the guide rod 720 in the connection cavity 700, then sleeve the spring 730 on the guide rod 720, and finally, threadedly connect the plug ring 620 to the opening of the connection cavity 700.

[0049] As Figures 6-7 shown, in this embodiment, a holding rod 640 is provided at the extending end of the guide rod 720.

[0050] In this embodiment, through the arrangement of the holding rod 640, when moving the guide rod 720, the guide rod 720 can be driven to move by pulling the holding rod 640, which is more convenient to use.

[0051] As Figure 6 shown, in this embodiment, a holding groove 621 is provided opposite to one end face of the plug ring 620.

[0052] In this embodiment, through the provision of the holding groove 621, when connecting the plug ring 620 to the opening of the connection cavity 700, a finger can be inserted into the holding groove 621 to drive the rotation of the plug ring 620, thereby realizing the disassembly and assembly of the plug ring 620 at the opening of the connection cavity 700.

[0053] As Figures 2-6 shown, in this embodiment, a stepped groove 610 is provided at the opening of the connection groove 300, and a boss portion 630 that overlaps the stepped groove 610 is provided on the connection shell 220.

[0054] In this embodiment, through the provision of the boss portion 630 and the stepped groove 610, when the connection shell 220 is installed in the connection groove 300, the boss portion 630 can be overlapped on the stepped groove 610, and the connection shell 220 can be installed in the stepped groove 610 by screwing a screw through the boss portion 630.

[0055] Working principle: When the existing thread cutting structure in the sewing machine fails, the electric push rod 420 can be activated to drive the sliding plate 410 to move towards the opening of the thread cutting cavity 320, so that the cutter body 412 extends out from the opening of the thread cutting cavity 320, and the cutter body 412 cuts the thread between the sewing material and the sewing needle 200; after the thread cutting operation is completed, the electric push rod 420 is activated to drive the sliding plate 410 to move away from the opening of the thread cutting cavity 320, which can drive the cutter body 412 to reset for another thread cutting; when the thread cutting box 210 needs to be removed from the sewing machine head 110, the guide rod 720 can be pulled to retract the connecting rod 711 into the connection cavity 700, and then the thread cutting box 210 can be removed.

Claims

1. A thread cutting mechanism for a sewing machine, characterized in that: It includes a thread cutting box (210) provided on the sewing machine head (110). Inside the thread cutting box (210), a thread cutting cavity (320) with an open lower end is provided along its height direction. Inside the thread cutting cavity (320), there is a liftable tool body (412). The tool body (412) can extend out of the thread cutting cavity (320) and move towards the sewing needle (200) to cut the sewing thread. Inside the thread cutting cavity (320), there is a driving component for driving the tool body (412) to extend and cut. The thread cutting box (210) is installed on the sewing machine head (110) through a connecting component.

2. The thread trimming mechanism of a sewing machine according to claim 1, characterized in that: The driving component includes a moving plate (400) that can be lifted and lowered inside the thread cutting cavity (320). On the top wall of the thread cutting cavity (320), there is a positioning plate (430) passing through the moving plate (400). The tool body (412) is movably arranged on the moving plate (400) through a sliding plate (410). On the positioning plate (430), there is a guiding groove (431). On the sliding plate (410), there is a sliding rod (441) sliding inside the guiding groove (431). The lifting of the moving plate (400) is used to drive the sliding rod (441) to slide along the guiding groove (431), driving the sliding plate (410) to drive the tool body (412) to extend out of the thread cutting cavity (320) and move towards the sewing thread to cut it.

3. The thread cutting mechanism of a sewing machine according to claim 2, characterized in that: On the top wall of the thread cutting cavity (320), there is an electric push rod (420) for driving the moving plate (400) to lift and lower.

4. The thread cutting mechanism of a sewing machine according to claim 2, characterized in that: On the bottom side surface of the moving plate (400), sliders (401) are relatively arranged along the moving direction of the sliding plate (410). On the sliding plate (410), there are sliding grooves sliding on the corresponding sliders (401).

5. The thread cutting mechanism of a sewing machine according to claim 1, characterized in that: At the lower end surface of the sewing machine head (110), there is a connecting groove (300); on the thread cutting box (210), there is a connecting part (310) extending into the connecting groove (300). On the connecting part (310), there is a connecting hole (311); on one side of the sewing machine head (110), there is an installation groove (600) communicating with the connecting groove (300). The connecting component includes a connecting shell (220) arranged inside the installation groove (600). Inside the connecting shell (220), there is a connecting cavity (700) with an open end. At the opening of the connecting cavity (700), there is a plug ring (620) threadedly connected. Inside the connecting cavity (700), there is also a moving circular plate (710) fitting with its inner wall. On one side of the moving circular plate (710), there is a guiding rod (720) passing through the plug ring (620) and extending out of the connecting cavity (700). A spring (730) is sleeved on the guiding rod (720). On the other side of the moving circular plate (710), there is a connecting rod (711) that can extend into the connecting hole (311).

6. The thread cutting mechanism of a sewing machine according to claim 4, characterized in that: At the extending end of the guiding rod (720), there is a holding rod (640).

7. The thread trimming mechanism of a sewing machine according to claim 5, characterized in that: On one end surface of the plug ring (620), holding grooves (621) are relatively arranged.

8. A thread cutting mechanism for a sewing machine according to claim 1, characterized in that: At the opening of the connecting groove (300), there is a step groove (610). On the connecting shell (220), there is a boss part (630) lapping inside the step groove (610).

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