Thread trimming device of sewing machine and sewing machine comprising thread trimming device

Abstract

The utility model discloses a thread trimming device of a sewing machine and the sewing machine with the thread trimming device, which belong to the technical field of sewing machine accessories, and comprise a blade, a first-stage oscillating bar mechanism, a second-stage oscillating bar mechanism, a third-stage oscillating bar mechanism and a telescopic component which are arranged in a panel of the sewing machine and are connected in sequence, the first-stage oscillating bar mechanism, the second-stage oscillating bar mechanism, the third-stage oscillating bar mechanism and the telescopic component are all connected with the sewing machine panel; the blade is arranged on one side above a bobbin case in the sewing machine panel; the sewing machine comprises a machine head and a sewing machine panel, the thread trimming device is installed in the sewing machine panel, and the blade is arranged on the lower right portion of feed dogs at the end of the sewing machine panel. The telescopic component drives the first-stage swing rod mechanism, the second-stage swing rod mechanism and the third-stage swing rod mechanism to drive the blade to swing, a sewing thread between a machine needle and a bobbin case can be cut off after sewing is finished, the downtime is shortened, the working efficiency is improved, and the labor intensity of workers is reduced; and the original sewing machine can be reformed, so that the production cost is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of sewing machine accessories, and particularly relates to a sewing machine thread cutting device and a sewing machine containing the thread cutting device. Background Art

[0002] With the increasing automation of sewing machines, automatic sewing machines have been widely promoted and applied. However, since most existing sewing machines require manual thread cutting after sewing to replace another product. This operation method will waste time, have low work efficiency, and also increase the labor intensity of workers, and is not suitable for mass production. If more advanced sewing equipment is purchased, the production cost will increase. Therefore, R & D personnel have modified the existing sewing machines and developed a thread cutting device to use mechanical thread cutting instead of manual thread cutting. Content of the Utility Model

[0003] In order to solve the above problems, the utility model provides a sewing machine thread cutting device and a sewing machine containing the thread cutting device.

[0004] To achieve the above object, the technical solutions adopted by the utility model are as follows:

[0005] A sewing machine thread cutting device, the thread cutting device includes a blade, a first-level swing rod mechanism, a second-level swing rod mechanism, a third-level swing rod mechanism and a telescopic component arranged inside the sewing machine panel, and the first-level swing rod mechanism, the second-level swing rod mechanism, the third-level swing rod mechanism and the telescopic component are all connected to the sewing machine panel; the blade is arranged above one side of the bobbin case inside the sewing machine panel and is connected to the free end of the first-level swing rod mechanism, the first-level swing rod mechanism, the second-level swing rod mechanism and the third-level swing rod mechanism are connected in sequence, the third-level swing rod mechanism is rotationally connected to the driving end of the telescopic component, and the telescopic component drives the third-level swing rod mechanism, the second-level swing rod mechanism and the first-level swing rod mechanism to swing in sequence for driving the blade to cut the sewing thread between the sewing needle and the bobbin case.

[0006] Further, the blade includes an arc-shaped blade body and a barb-shaped blade head, the blade head is arranged below the end of the blade body, the cutting edge of the blade head is arranged in a groove, the rear part of the blade body is a stepped connecting seat, the front part is an arc-shaped blade rod, the arc-shaped groove of the blade rod faces the direction of the bobbin case, and a limiting plate connected to the sewing machine panel is arranged on the side of the blade head.

[0007] Further, the limiting plate is a special-shaped connecting plate connected to the sewing machine panel, the upper end of the limiting plate is upturned and provided with an inward bend for tightly pressing against the outside of the blade head; a horizontal mounting platform is arranged at the lower end of the limiting plate, and the mounting platform is connected to the inner wall of the sewing machine panel through bolts.

[0008] Further, the first swing rod mechanism includes a first swing rod, a first rotating shaft, and a first cam. The movable end of the first swing rod is connected to the blade, the fixed end of the first swing rod is fixedly connected to the upper end of the first rotating shaft, the lower end of the first rotating shaft is fixedly connected to the fixed end of the first cam, and the movable end of the first cam is rotatably connected to the free end of the second swing rod mechanism; the first rotating shaft is rotatably engaged with the positioning groove inside the sewing machine panel.

[0009] Further, the second swing rod mechanism includes a second swing rod, a second rotating shaft, and a second cam. The free end of the second swing rod is rotatably connected to the first cam, the connecting end of the second swing rod is rotatably connected to the movable end of the second cam, and the driving end of the second cam is rotatably connected to the movable end of the third swing rod mechanism; the second rotating shaft is rotatably engaged with the middle part of the second cam, and the upper end of the second rotating shaft is connected to the sewing machine panel through a mounting block.

[0010] Further, the third swing rod mechanism includes a connecting rod, a third swing rod, a third rotating shaft, and a third cam. One end of the connecting rod is rotatably connected to the driving end of the second cam, a long hole for the pin shaft to move is provided at the other end of the connecting rod, the pin shaft is arranged at the free end of the third swing rod, the fixed end of the third swing rod is fixedly connected to the upper part of the third rotating shaft, the lower part of the third rotating shaft is fixedly connected to the fixed end of the third cam, and the movable end of the third cam is rotatably connected to the driving end of the telescopic member.

[0011] Further, the middle part of the third rotating shaft is connected to the sewing machine panel through a mounting plate, and the telescopic member is connected to the sewing machine panel through an L-shaped connecting plate.

[0012] Further, the telescopic member is an electric push rod or a cylinder.

[0013] A sewing machine includes a machine head and a sewing machine panel. The above-mentioned thread cutting device is arranged inside the sewing machine panel, and the blade is arranged at the lower right of the feed dog at the end of the sewing machine panel.

[0014] Compared with the prior art, the technical progress achieved by the present invention is as follows:

[0015] By installing a blade driven by a telescopic member, a first swing rod mechanism, a second swing rod mechanism, and a third swing rod mechanism inside the sewing machine panel, the present invention can cut the sewing thread between the sewing needle and the bobbin case after sewing is completed, eliminating the need for manual thread cutting. Mechanized operation reduces downtime, improves work efficiency, and reduces the labor intensity of workers. The present invention can be modified based on the original sewing machine. The first swing rod mechanism with a blade is sequentially connected to the second swing rod mechanism, the third swing rod mechanism, and the telescopic member, and installed on the top of the sewing machine panel, eliminating the need for additional equipment purchase and reducing production costs. Description of the Drawings

[0016] The accompanying drawings are used to provide a further understanding of the present utility model and form a part of the description. They are used together with the embodiments of the present utility model to explain the present utility model and do not constitute a limitation to the present utility model.

[0017] In the accompanying drawings:

[0018] Figure 1 is a schematic structural view of a thread trimming device for a sewing machine provided by an embodiment of the present utility model;

[0019] Figure 2 is Figure 1 a top view of the thread trimming device in

[0020] Figure 3 is Figure 1 an installation schematic view of the thread trimming device in

[0021] Figure 4 is a schematic structural view of a blade in an embodiment of the present utility model;

[0022] Figure 5 is a schematic structural view of a limit plate in an embodiment of the present utility model;

[0023] Figure 6 is a schematic structural view of a sewing machine including a thread trimming device provided by an embodiment of the present utility model;

[0024] In the figure: 00 - machine head, 01 - sewing machine panel, 02 - bobbin case, 03 - sewing needle, 04 - mounting plate, 05 - L-shaped connecting plate, 06 - feed dog; 07 - mounting block; 08 - cover plate; 09 - bobbin case mounting hole;

[0025] 1 - blade, 11 - tool body, 12 - tool tip, 13 - cutting edge; 2 - telescopic member; 3 - limit plate, 30 - mounting table, 31 - bend;

[0026] 100 - first swing rod mechanism, 101 - first swing rod, 102 - first rotating shaft, 103 - first cam;

[0027] 200 - second swing rod mechanism, 201 - second swing rod, 202 - second rotating shaft, 203 - second cam;

[0028] 300 - third swing rod mechanism, 301 - connecting rod, 302 - third swing rod, 303 - third rotating shaft, 304 - third cam, 305 - long slot. Detailed implementation manners

[0029] The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0030] As shown in Figure 1 , Figure 2 and Figure 3 , a thread cutting device for a sewing machine provided by an embodiment of the present invention includes a blade 1, a first-level swing rod mechanism 100, a second-level swing rod mechanism 200, a third-level swing rod mechanism 300, and a telescopic member 2 disposed inside the sewing machine panel 01. The first-level swing rod mechanism 100, the second-level swing rod mechanism 200, the third-level swing rod mechanism 300, and the telescopic member 2 are all connected to the sewing machine panel 1. The blade 2 is disposed above one side of the bobbin case 02 inside the sewing machine panel 1 and is connected to the free end of the first-level swing rod mechanism 100. The first-level swing rod mechanism 100, the second-level swing rod mechanism 200, and the third-level swing rod mechanism 300 are connected in sequence. The third-level swing rod mechanism 300 is rotationally connected to the driving end of the telescopic member 2. After sewing is completed, the telescopic member 2 is started. The telescopic member 2 drives the third-level swing rod mechanism 300, the second-level swing rod mechanism 200, and the first-level swing rod mechanism 100 to swing in sequence, which can drive the blade 1 to swing, and then cut the sewing thread (not shown in the figure) between the sewing needle 03 and the bobbin case 02. Adopting this solution can reduce the downtime, reduce the auxiliary labor time and workload, improve the work efficiency, and is especially suitable for mass production.

[0031] In a specific embodiment of the present invention, as shown in Figure 4 , the blade 1 includes an arc-shaped blade body 11 and an inverted hook-shaped blade head 12. The blade head 12 is disposed below the end of the blade body 11. The cutting edge 13 of the blade head 12 is disposed in a groove. The rear part of the blade body 11 is connected to the first-level swing rod mechanism 100. The arc-shaped groove of the blade body 11 faces the direction of the bobbin case 02. A limiting plate 3 connected to the sewing machine panel 01 is provided on the side of the blade head 12. When the blade 1 swings with the first-level swing rod mechanism 100, the sewing thread can enter the groove of the blade head 12 and contact the cutting edge 3 during the return process of the blade 1, and the sewing thread can be quickly cut.

[0032] As a preferred structure, as shown in Figure 5 , the limiting plate 3 is a special-shaped connecting plate connected to the sewing machine panel 01. The upper end of the limiting plate 3 is upturned and provided with an inward bend 31 for tightly pressing against the outside of the blade head 12. The lower end of the limiting plate 3 is provided with a horizontal mounting platform 30. The mounting platform 30 is connected to the inner wall of the sewing machine panel 01 by bolts. When the blade 1 moves towards the feed dog 06, the limiting plate 3 can limit the blade 1 to avoid excessive outward swing amplitude resulting in a change in the return trajectory.

[0033] In a specific embodiment of the present utility model, as Figure 1 , 2 shown, the first-level swing rod mechanism 100 includes a first-level swing rod 101, a first-level rotating shaft 102, and a first-level cam 103. The movable end of the first-level swing rod 101 is connected to the step connection seat 110 of the blade 1. The fixed end of the first-level swing rod 101 is fixedly connected to the upper end of the first-level rotating shaft 102. The lower end of the first-level rotating shaft 102 is fixedly connected to the fixed end of the first-level cam 103. The movable end of the first-level cam 103 is rotatably connected to the free end of the second-level swing rod mechanism 200. The first-level rotating shaft 101 is rotationally matched with the positioning groove inside the sewing machine panel 01. During application, the first-level cam 103 can swing left and right under the drive of the second-level swing rod mechanism 200, and drive the first-level swing rod 101 and the blade 1 at its end to rotate around the central axis of the first-level rotating shaft 102, so as to achieve the purpose of the blade 1 swinging back and forth relative to the sewing thread under the feed dog 06.

[0034] In a specific embodiment of the present utility model, as Figures 1 - 3 shown, the second-level swing rod mechanism 200 includes a second-level swing rod 201, a second-level rotating shaft 202, and a second-level cam 203. The free end of the second-level swing rod 201 is rotatably connected to the first-level cam 103. The connecting end of the second-level swing rod 201 is rotatably connected to the movable end of the second-level cam 203. The driving end of the second-level cam 203 is rotatably connected to the movable end of the third-level swing rod mechanism 300. The second-level rotating shaft 202 is rotationally matched with the middle part of the second-level cam 203. The upper end of the second-level rotating shaft 202 is connected to the sewing machine panel 01 through the mounting block 07. During application, the second-level cam 203 rotates around the second-level rotating shaft 202 under the drive of the third-level swing rod mechanism 300, and then drives the second-level swing rod 201 to move left and right relative to the bobbin case 02 and the feed dog 06 direction. The second-level cam 203 then drives the second-level swing rod 201 to move left and right, and further drives the first-level cam 103 to swing left and right.

[0035] In a specific embodiment of the present utility model, as Figures 1 - 3As shown in the figure, the three-stage swing rod mechanism 300 includes a connecting rod 301, a three-stage swing rod 302, a three-stage rotating shaft 303 and a three-stage cam 304. One end of the connecting rod 301 is rotatably connected to the driving end of the second-stage cam 203. The other end of the connecting rod 301 is provided with a long slot 305 for the movement of a pin shaft (not shown in the figure). The pin shaft is arranged at the free end of the three-stage swing rod 302. The fixed end of the three-stage swing rod 302 is fixedly connected to the upper part of the three-stage rotating shaft 303. The lower part of the three-stage rotating shaft 303 is fixedly connected to the fixed end of the three-stage cam 304. The movable end of the three-stage cam 304 is rotatably connected to the driving end of the telescopic member 2. Among them, the middle part of the three-stage rotating shaft 303 is connected to the sewing machine panel 01 through a mounting plate 04. The telescopic member 2 is connected to the sewing machine panel 01 through an L-shaped connecting plate 05. A connecting ear is provided at the end of the three-stage cam 304, and a connecting shaft matching with the connecting ear is provided at the driving end of the telescopic member 2. During application, when the telescopic member is started, it can drive the three-stage cam 304 to swing left and right around the three-stage rotating shaft 303. The three-stage rotating shaft 303 then drives the three-stage swing rod 302 to rotate. During the rotation of the three-stage swing rod 302, it will drive the second-stage cam 203 to rotate around the second-stage rotating shaft 202 through the connecting rod 301.

[0036] During specific design, the telescopic member 2 can be selected as an electric push rod or a cylinder. The button for controlling the start and stop of the telescopic member can be installed on the sewing machine head or the sewing machine panel. If the sewing machine is an automatic sewing machine controlled by a computer, the telescopic member can be connected to the controller of the sewing machine, and the automatic thread cutting operation can be realized.

[0037] As Figure 6 As shown in the figure, the present invention also provides a sewing machine, including a sewing machine head 00 and a sewing machine panel 01. The above-mentioned thread cutting device is arranged inside the sewing machine panel 01. The blade 1 is arranged right below the feed dog 06 at the end of the sewing machine panel 01. All sewing machines containing the above-mentioned thread cutting device are within the protection scope of the present invention.

[0038] To sum up, the present invention has the effects of simple and compact structure and fast thread cutting. It can utilize the internal space of the original sewing machine panel. After successively connecting the telescopic member, the first-stage swing rod mechanism, the second-stage swing rod mechanism, the third-stage swing rod mechanism and the blade, and then installing them inside the sewing machine panel, there is no need to purchase additional equipment, reducing the production cost. By starting the telescopic member, the swing of the blade can be realized, and the sewing thread between the sewing needle and the bobbin case can be automatically cut off after sewing is completed, without manually cutting the sewing thread. This mechanized operation reduces the downtime, saves the auxiliary time for manual thread cutting, improves the work efficiency, and reduces the workload and labor intensity of the staff.

[0039] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the scope of protection of the claims of the present utility model.

Claims

1. A thread trimming device for a sewing machine, characterized in that: The thread cutting device comprises a blade, a primary rocking rod mechanism, a secondary rocking rod mechanism, a tertiary rocking rod mechanism and a telescopic component arranged inside a sewing machine panel, wherein the primary rocking rod mechanism, the secondary rocking rod mechanism, the tertiary rocking rod mechanism and the telescopic component are all connected to the sewing machine panel; the blade is arranged on one side above the bobbin case inside the sewing machine panel and is connected to the free end of the primary rocking rod mechanism, the primary rocking rod mechanism, the secondary rocking rod mechanism and the tertiary rocking rod mechanism are connected in sequence, the tertiary rocking rod mechanism is rotationally connected to the driving end of the telescopic component, and the telescopic component drives the tertiary rocking rod mechanism, the secondary rocking rod mechanism and the primary rocking rod mechanism to swing in sequence, so as to drive the blade to cut the sewing thread between the needle and the bobbin case.

2. A thread trimming device for a sewing machine according to claim 1, characterized in that: The blade includes an arc-shaped blade body and a barbed-hook blade head, wherein the blade head is arranged below the end of the blade body, and the blade of the blade head is arranged in a groove. The rear part of the blade body is connected to a primary rocker mechanism, and the arc-shaped groove of the blade body faces the direction of the shuttle housing. A limiting plate connected to a sewing machine panel is provided on the side of the blade head.

3. A thread trimming device for a sewing machine according to claim 2, characterized in that: The limiting plate is a special-shaped connecting plate connected to the sewing machine panel. The upper end of the limiting plate is raised and has an inward bend for pressing against the outer side of the cutter head. The lower end of the limiting plate is provided with a horizontal mounting platform, which is connected to the inner wall of the sewing machine panel by bolts.

4. A thread trimming device for a sewing machine according to claim 1, characterized in that: The primary rocker mechanism includes a primary rocker, a primary rotating shaft and a primary cam. The movable end of the primary rocker is connected to the blade, the fixed end of the primary rocker is fixedly connected to the upper end of the primary rotating shaft, the lower end of the primary rotating shaft is fixedly connected to the fixed end of the primary cam, and the movable end of the primary cam is rotationally connected to the free end of the secondary rocker mechanism; the primary rotating shaft is rotationally matched with the sewing machine panel.

5. A thread trimming device for a sewing machine according to claim 4, characterized in that: The secondary rocker mechanism includes a secondary rocker, a secondary rotating shaft and a secondary cam. The free end of the secondary rocker is rotationally connected to the primary cam, the connecting end of the secondary rocker is rotationally connected to the movable end of the secondary cam, and the driving end of the secondary cam is rotationally connected to the movable end of the tertiary rocker mechanism; the secondary rotating shaft is rotationally matched with the middle part of the secondary cam, and the upper end of the secondary rotating shaft is connected to the sewing machine panel.

6. A thread trimming device for a sewing machine according to claim 5, characterized in that: The three-stage rocker mechanism includes a connecting rod, a three-stage rocker, a three-stage rotating shaft and a three-stage cam. One end of the connecting rod is rotatably connected to the driving end of the two-stage cam, and the other end of the connecting rod is provided with a long hole for the movement of the pin shaft. The pin shaft is arranged at the free end of the three-stage rocker. The fixed end of the three-stage rocker is fixedly connected to the upper part of the three-stage rotating shaft, and the lower part of the three-stage rotating shaft is fixedly connected to the fixed end of the three-stage cam. The movable end of the three-stage cam is rotatably connected to the driving end of the telescopic component.

7. A thread trimming device for a sewing machine according to claim 6, characterized in that: The middle part of the three-stage rotating shaft is connected to the sewing machine panel through a mounting plate, and the telescopic component is connected to the sewing machine panel through an L-shaped connecting plate.

8. A thread trimming device for a sewing machine according to claim 1, characterized in that: The telescopic component is an electric push rod or a cylinder.

9. A sewing machine, characterized in that: It comprises a machine head and a sewing machine panel, wherein the interior of the sewing machine panel is provided with a thread trimming device as described in any one of claims 1 to 8, and the blade is arranged at the lower right side of the feed dog at the end of the sewing machine panel.

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