Lower thread trimming mechanism for automatic thread trimming of sewing machine

Abstract

The utility model provides an automatic lower thread trimming mechanism of a sewing machine, which comprises a cutterhead main body, a swing rod, a fixed cutter and a movable cutter, the swing rod, the fixed cutter and the movable cutter are fixed on the cutterhead main body, the swing rod is used for being connected with a starting device to drive the mechanism to work, and the fixed cutter and the movable cutter are used for trimming threads. The fixed cutter is detachably fixed on the fixed cutter frame, the movable cutter is detachably fixed on the movable cutter frame, the fixed cutter frame and the movable cutter frame are connected through a cutter frame connecting rod and then are connected with the cutter head main body through the cutter frame connecting rod, and the movable cutter is provided with a first wire cutting blade, a second wire cutting blade, a third wire pulling hook and a fourth wire collecting fork. The third wire drawing hook is arranged below the second wire cutting blade, the side lines of the third wire drawing hook are smooth and free of blades, and the fourth wire winding fork is arranged below the outer portion of the third wire drawing hook, and the side lines of the fourth wire winding fork are smooth and free of blades. The thread trimming device is reasonable in structure, high in thread trimming quality, stable in performance and convenient to use, and solves the problem that thread trimming quality is poor due to the fact that stitches on cloth are too short and sewn cloth is split.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewing machine spare part's manufacturing improvement technical field especially relates to a sewing machine automatic thread cutting down cutting mechanism. BACKGROUND

[0002] The existing sewing machine automatic thread cutting down cutting mechanism does not have the thread cutting function on the machine or although it can realize the sewing machine automatic thread cutting function in theory, but lacks the necessary stability and reliability in actual operation. And the moving knife of the existing sewing machine automatic thread cutting is composed of two thread cutting blades, which can only be applied to simple sewing thread or low density fabric sewing. When the specifications of the sewing thread or fabric change, the existing sewing machine leaves too short thread on the fabric after finishing sewing, and the sewn clothes will be off-thread. It needs to consume a lot of manpower and time to recondition, and the manufacturing cost of the finished clothes is high.

[0003] In actual operation, an automatic thread cutting down cutting mechanism of a sewing machine with reasonable structure, high thread cutting quality, stable performance and convenient use is urgently needed to solve the problem of poor thread cutting quality caused by the off-thread of the sewn clothes when the specifications of the sewing thread or fabric change and the existing sewing machine leaves too short thread on the fabric after finishing sewing. SUMMARY

[0004] To solve the above technical problems, the utility model provides a sewing machine automatic thread cutting down cutting mechanism which is composed of a knife disc main body, a swing lever, a fixed knife and a moving knife fixed on the knife disc main body, the swing lever is used for connecting a starting device to drive the mechanism to work, and the fixed knife and the moving knife are used for thread cutting, characterized in that:

[0005] The knife disc main body is provided with a detachable fixed knife holder and a moving knife holder, the fixed knife is fixed on the fixed knife holder and can be detached, the moving knife is fixed on the moving knife holder and can be detached, and the fixed knife holder and the moving knife holder are connected through a knife holder connecting rod and then connected with the knife disc main body through the knife holder connecting rod.

[0006] The moving knife is provided with a first thread cutting blade, a second thread cutting blade, a third thread pulling hook and a fourth thread collecting fork, the third thread pulling hook is arranged below the second thread cutting blade, the edges of the third thread pulling hook are smooth and have no blade, and are used for pulling the thread to the designed length standard and keeping the thread unbroken before the second thread cutting blade cuts the thread, the fourth thread collecting fork is arranged below and outward of the third thread pulling hook, the edges of the fourth thread collecting fork are smooth and have no blade, and are used for collecting all the thread into the third thread pulling hook and keeping the thread unbroken before the third thread pulling hook pulls the thread.

[0007] The moving knife is fixed on the moving knife holder through a moving knife fixing screw and a thread loosening piece.

[0008] The fixed knife is fixed on the fixed knife frame through a fixed knife fixing screw, a fixed knife fixing block and a thread clamping piece.

[0009] The fixed knife frame and the movable knife frame are fixed on the knife frame connecting rod through a knife frame fixing sleeve and an external hexagonal screw.

[0010] The knife frame connecting rod is further fixed on the cutter disc main body through a rotating sleeve screw and a rotating sleeve.

[0011] The number of the knife frame fixing sleeve, the external hexagonal screw, the knife frame connecting rod, the rotating sleeve screw and the rotating sleeve is two sets.

[0012] The fixed knife frame is further provided with a pad and a pressure piece through a pressure piece fixing screw.

[0013] The fixed knife frame is further provided with a pressure adjusting plate and a pressure adjusting screw through a pressure adjusting plate fixing screw.

[0014] The cutter disc main body is further provided with a return spring through a return spring fixing screw.

[0015] The cutter disc main body is further provided with a movable knife frame limiting plate and a movable knife frame baffle through a limiting plate fixing screw.

[0016] The cutter disc main body is further provided with a limiting pressure plate and a fixed knife frame limiting plate through a limiting pressure plate fixing screw.

[0017] The swing rod is connected to the cutter disc main body through a swing rod pad, a swing rod fixing screw, and the swing rod is connected to a starting device through a swing rod connecting screw.

[0018] The utility model discloses the beneficial effect lies in:

[0019] The sewing machine automatic thread cutting and cutting mechanism can realize the function of trimming the thread on the machine after each sewing, reasonably trims the length of the thread end on the garment fabric without thread falling, has good sewing effect, avoids the process of manual thread cutting of the sewing machine operator, improves the quality of the garment, stabilizes the overall quality of the garment, thus greatly improves the work efficiency of the operator, has very reliable stability, makes the comprehensive work efficiency of the existing production process at least 4 times higher than the original production process, and can be more widely applicable to the thickness and texture of the sewing thread.

[0020] The sewing machine automatic thread cutting and cutting mechanism has reasonable structure, simple and convenient machine trimming and obvious effect, and has important significance in actual production. DRAWINGS:

[0021] Fig. 1 It is a whole structure exploded view of the utility model.

[0022] Fig. 2 It is the exploded structural schematic view of the movable cutter holder of the utility model.

[0023] Fig. 3 It is the structural schematic view of the movable cutter of the utility model.

[0024] The figure mark:

[0025] 1, cutter disc main body 2, swing rod 3, fixed cutter 4, movable cutter 5, fixed cutter holder 6, movable cutter holder

[0026] 7, cutter holder connecting rod 8, movable cutter fixing screw 9, line releasing piece 10, fixed cutter fixing screw

[0027] 11, fixed cutter fixing block 12, line clamping piece 13, cutter holder fixing sleeve 14, outer hexagonal screw

[0028] 15, rotating sleeve screw 16, rotating sleeve 17, pressure piece fixing screw 18, gasket

[0029] 19, pressure piece 20, pressure adjusting plate fixing screw 21, pressure adjusting plate

[0030] 22, pressure adjusting screw 23, reset spring fixing screw 24, reset spring

[0031] 25, limiting plate fixing screw 26, movable cutter holder limiting plate 27, movable cutter holder baffle

[0032] 28, limiting pressure plate fixing screw 29, limiting pressure plate 30, fixed cutter holder limiting plate

[0033] 31, swing rod gasket 32, swing rod fixing screw 33, swing rod connecting screw

[0034] 4-1, first tangent cutter edge 4-2, second tangent cutter edge

[0035] 4-3, third wire pulling hook 4-4, fourth wire collecting fork. Specific implementation:

[0036] The utility model will be further explained in detail as follows: the embodiment is implemented under the premise of the utility model technical scheme, and detailed implementation modes are given, but the protection scope of the utility model is not limited to the following examples.

[0037] For example, Figs. 1-3The utility model provides a kind of automatic thread cutting down cutting mechanism of sewing machine, it is composed of cutter main body 1 and swing lever 2, fixed knife 3 and moving knife 4 fixed on the cutter main body 1, the swing lever 2 is used to connect starting device driving mechanism work, the fixed knife 3 and the moving knife 4 are used to cut thread, it is characterized by: the cutter main body 1 is provided with detachable fixed knife holder 5 and moving knife holder 6, the fixed knife 3 is fixed on the fixed knife holder 5 and can be detached, the moving knife 4 is fixed on the moving knife holder 6 and can be detached, the fixed knife holder 5 is connected with the moving knife holder 6 by knife holder connecting rod 7, then it is connected with the cutter main body 1 by the knife holder connecting rod 7.

[0038] The moving knife 4 is provided with first thread cutting edge 4-1, second thread cutting edge 4-2, third thread pulling hook 4-3 and fourth thread collecting fork 4-4, the third thread pulling hook 4-3 is arranged below the second thread cutting edge 4-2, the edge of the third thread pulling hook 4-3 is smooth, without blade, for pulling the thread to the designed length standard and not breaking before the second thread cutting edge 4-2 cuts thread, the fourth thread collecting fork 4-4 is arranged below the third thread pulling hook 4-3, the edge of the fourth thread collecting fork 4-4 is smooth, without blade, for collecting all threads into the third thread pulling hook 4-3 and not breaking before the third thread pulling hook 4-3 pulls thread.

[0039] The moving knife 4 is fixed on the moving knife holder 6 by moving knife fixing screw 8 and thread loosening piece 9, the fixed knife 3 is fixed on the fixed knife holder 5 by fixed knife fixing screw 10, fixed knife fixing block 11 and thread clamping piece 12.

[0040] The fixed knife holder 5 and the moving knife holder 6 are fixed on the knife holder connecting rod 7 by knife holder fixing sleeve 13 and external hexagonal screw 14, and the knife holder connecting rod 7 is fixed on the cutter main body 1 by rotating sleeve screw 15 and rotating sleeve 16.

[0041] The number of the knife holder fixing sleeve 13, external hexagonal screw 14, knife holder connecting rod 7, rotating sleeve screw 15 and rotating sleeve 16 is two sets.

[0042] The fixed knife holder 5 is also fixed with pad 18 and pressure piece 19 by pressure piece fixing screw 17, and the fixed knife holder 5 is also fixed with pressure adjusting plate 21 and pressure adjusting screw 22 by pressure adjusting plate fixing screw 20.

[0043] The cutter main body 1 is also fixed with return spring 24 by return spring fixing screw 23.

[0044] The cutter main body 1 is also fixed with moving knife holder limiting plate 26 and moving knife holder baffle 27 by limiting plate fixing screw 25, and the cutter main body 1 is also fixed with limiting pressure plate 29 and fixed knife holder limiting plate 30 by limiting pressure plate fixing screw 28.

[0045] The swing rod 2 is connected to the cutter head body 1 through a swing rod gasket 31 and a swing rod fixing screw 32, and the swing rod 2 is connected to an activating device through a swing rod connecting screw 33.

[0046] The lower thread cutting mechanism of the automatic thread cutter has reasonable structure and is simple and convenient to use. For example, the movable cutter 4 and the fixed cutter 3 are easy-to-damage parts, which are used for a long time and need to be frequently replaced. The movable cutter 4 and the fixed cutter 3 can be disassembled and replaced on the sewing machine without disassembling the entire lower thread cutting mechanism, which brings great convenience to the maintenance workers.

[0047] The above merely describes the preferred embodiments of the present application, and these embodiments are different implementations based on the overall concept of the present application. The protection scope of the present application is not limited to this, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A sewing machine automatic thread cutting mechanism, comprising a cutter body (1), a swing lever (2) fixed on the cutter body (1), a fixed cutter (3) and a moving cutter (4), the swing lever (2) is used for connecting a starting device to drive the mechanism to work, and the fixed cutter (3) and the moving cutter (4) are used for cutting thread, characterized in that: a detachable fixed cutter holder (5) and a moving cutter holder (6) are arranged on the cutter body (1), the fixed cutter (3) is detachably fixed on the fixed cutter holder (5), the moving cutter (4) is detachably fixed on the moving cutter holder (6), and the fixed cutter holder (5) and the moving cutter holder (6) are connected through a cutter holder connecting rod (7) and then connected to the cutter body (1) through the cutter holder connecting rod (7); the moving cutter (4) is provided with a first thread cutting blade (4-1), a second thread cutting blade (4-2), a third thread pulling hook (4-3) and a fourth thread collecting fork (4-4), the third thread pulling hook (4-3) is arranged below the second thread cutting blade (4-2), the edges of the third thread pulling hook (4-3) are smooth and have no blade, the third thread pulling hook (4-3) is used for pulling the thread to a designed length and keeping the thread unbroken before the second thread cutting blade (4-2) cuts the thread, the fourth thread collecting fork (4-4) is arranged below and outward of the third thread pulling hook (4-3), the edges of the fourth thread collecting fork (4-4) are smooth and have no blade, and the fourth thread collecting fork (4-4) is used for collecting all the thread into the third thread pulling hook (4-3) and keeping the thread unbroken before the third thread pulling hook (4-3) pulls the thread. The moving cutter (4) is fixed on the moving cutter holder (6) through a moving cutter fixing screw (8) and a thread releasing piece (9), and the fixed cutter (3) is fixed on the fixed cutter holder (5) through a fixed cutter fixing screw (10), a fixed cutter fixing block (11) and a thread clamping piece (12). The fixed cutter holder (5) and the moving cutter holder (6) are fixed on the cutter holder connecting rod (7) through a cutter holder fixing sleeve (13) and an external hexagonal screw (14), and the cutter holder connecting rod (7) is fixed on the cutter body (1) through a rotating sleeve screw (15) and a rotating sleeve (16).

2. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein The number of the cutter holder fixing sleeve (13), the external hexagonal screw (14), the cutter holder connecting rod (7), the rotating sleeve screw (15) and the rotating sleeve (16) is two sets.

3. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein The fixed cutter holder (5) is further provided with a spacer (18) and a pressure piece (19) fixed through a pressure piece fixing screw (17), and the fixed cutter holder (5) is further provided with a pressure adjusting plate (21) and a pressure adjusting screw (22) fixed through a pressure adjusting plate fixing screw (20).

4. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 3, wherein The cutter body (1) is further provided with a return spring (24) fixed through a return spring fixing screw (23).

5. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein The cutter body (1) is further provided with a moving cutter holder limiting plate (26) and a moving cutter holder baffle (27) fixed through a limiting plate fixing screw (25), and the cutter body (1) is further provided with a limiting pressure plate (29) and a fixed cutter holder limiting plate (30) fixed through a limiting pressure plate fixing screw (28).

6. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein ​ 7. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein ​ 8. The automatic thread trimming and cutting mechanism of a sewing machine according to claim 1, wherein, The swing rod (2) is connected on the cutter head main body (1) through a swing rod gasket (31) and a swing rod fixing screw (32), and the swing rod (2) is connected with a starting device through a swing rod connecting screw (33).

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