Sewing machine with automatic thread cutting device

Abstract

The invention provides a sewing machine with an automatic thread cutting device. The sewing machine comprises a machine body; the wire tightening unit is arranged on the machine body; the rocker arm unit is pivotally arranged on the machine body; the thread hooking unit is arranged on the rocker arm unit and comprises a thread hooking seat, an outer thread hooking piece, a rotating shuttle and an inner thread hooking piece; and the wire cutting unit is arranged on the rocker arm unit and comprises an inner wire cutter and an outer wire cutter. The inner thread can be automatically cut off by matching the rotation action of an inner thread hooking piece of the thread hooking unit with the telescopic action of an inner thread cutter of the thread cutting unit; in addition, the action of tightening the outer thread through the thread tightening unit is matched with the rotation action of an outer thread hooking piece of the thread hooking unit and the telescopic action of an outer thread cutter of the thread cutting unit, so that the outer thread is automatically cut off, sewing operation interruption is avoided, the sewing operation time is effectively saved, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to a sewing machine, in particular to a sewing machine with an automatic thread cutting device. Background Art

[0002] When the sewing machine completes the sewing operation, the sewing thread left on the material to be sewn must be cut off before the material to be sewn can be removed. However, the operator must pull out the material to be sewn by hand, and at the same time pull out the sewing thread and reserve a section of the sewing thread to facilitate the next sewing operation, and finally use scissors to cut the sewing thread.

[0003] This method of manually cutting the suture thread will seriously affect the sewing speed and production capacity for production lines that perform a large number of sewing operations. In addition, it is not easy to leave a fixed length of suture thread ends on the needle bar by manually cutting the suture thread. Once the suture thread ends left are too long, the defect of waste of suture material will be highlighted. Once the suture thread ends left are too short, the suture thread will easily fall off the needle bar and need to be re-threaded, resulting in interruption of sewing operations, wasted time and reduced work efficiency.

[0004] For the relevant actuation methods of the sewing machine, reference may be made to Taiwan Application No. 107119370 “Lower thread supply device and sewing method for sewing machine”, Taiwan Application No. 099219194 “Improved structure of sewing machine”, etc. Summary of the invention

[0005] The object of the present invention is to provide a sewing machine with an automatic thread trimming device which can solve one of the above problems.

[0006] To achieve the aforementioned purpose, the present invention provides a sewing machine with an automatic thread cutting device, comprising: a machine body; a thread tensioning unit, which is arranged on the machine body and allows an outer thread to pass through, and the thread tensioning unit can be actuated between a tightening position and a releasing position. When the thread tensioning unit is in the tightening position, the thread tensioning unit tightens the outer thread, and when the thread tensioning unit is in the releasing position, the thread tensioning unit releases the outer thread; a rocker unit, which can be pivotally arranged on the machine body; a thread hooking unit, which is arranged on the rocker unit and includes a thread hooking seat, an outer thread hook, a rotary shuttle, and an inner thread hook; the thread hooking seat is fixed on the rocker unit and allows the outer thread to pass through; the outer thread hook can be rotatably arranged in the thread hooking seat between an outer thread cutting preparation position and an outer thread cutting position, and has an outer thread hook portion for hooking the outer thread; the rotary shuttle can be eccentrically rotatably arranged in the thread hooking seat and provides an inner thread; the inner thread hook can be rotatably arranged in the hooking seat The invention discloses a wire holder, wherein the wire holder has an inner wire hook part for hooking the inner wire to an inner wire cutting position; and a wire cutting unit, which is arranged on the rocker arm unit and includes an inner wire cutter and an outer wire cutter; the inner wire cutter is arranged on the rocker arm unit so as to be movable between a first initial position and a first wire cutting position, and has an inner wire blade part for cutting the inner wire, and when the inner wire hook part hooks the inner wire to the inner wire cutting position and the inner wire cutter is at the first wire cutting position, the inner wire blade part cuts the inner wire; the outer wire cutter is arranged on the rocker arm unit so as to be movable between a second initial position and a second wire cutting position, and has an outer wire blade part for cutting the outer wire, and when the outer wire cutter is at the second wire cutting position and the outer wire hook part hooks the outer wire to the outer wire cutting position and the wire tensioning unit is at the tightening position, the outer wire cutter is controlled to be moved from the second wire cutting position to the second initial position, and the outer wire blade part cuts the outer wire.

[0007] The utility model has the advantages that the inner thread can be automatically cut off by the rotation of the inner thread hook of the thread hook unit and the extension and retraction of the inner thread cutter of the thread cutting unit; in addition, the outer thread can be automatically cut off by the action of tightening the outer thread of the thread tensioning unit and the rotation of the outer thread hook of the thread hook unit and the extension and retraction of the outer thread cutter of the thread cutting unit, thereby avoiding the interruption of sewing operation, effectively saving the sewing operation time and improving the work efficiency.

[0008] Preferably, the wire-tensioning unit includes a wire-tensioning seat, a wire-tensioning pressure cylinder and a wire-tensioning block; the wire-tensioning seat is fixed to the machine body and has a wire-tensioning space, the wire-tensioning pressure cylinder has a wire-tensioning cylinder body fixed to the wire-tensioning seat, and a wire-tensioning piston rod provided on the wire-tensioning cylinder body and capable of moving between the tightening position and the release position; the wire-tensioning block is fixed to the wire-tensioning piston rod and has a wire-tensioning through hole for the outer wire to pass through, when the wire-tensioning unit is in the tightening position, the wire-tensioning piston rod brings the wire-tensioning block to the wire-tensioning space, so that the outer wire is clamped between the wire-tensioning block and the wire-tensioning seat, and when the wire-tensioning unit is in the release position, the wire-tensioning piston rod brings the wire-tensioning block away from the wire-tensioning space, so that the outer wire is not clamped by the wire-tensioning block and the wire-tensioning seat.

[0009] Preferably, the outer thread hook has a ring portion, a receiving space surrounded by the ring portion and for receiving the rotary hook, a ring groove recessed around the ring portion and for receiving part of the inner thread, and the outer thread hook portion disposed on the ring portion.

[0010] Preferably, the inner wire hook has a driven portion, an inner wire hook portion arranged on the driven portion, the inner wire hook portion is arc-shaped and has a first arc end, a second arc end opposite to the first arc end, and an arc-shaped groove recessed between the first arc end and the second arc end; when the inner wire hook hooks the inner wire to the inner wire cutting position, the inner wire portion is located in the annular groove of the outer wire hook, and the inner wire portion is located in the arc-shaped groove of the inner wire hook.

[0011] Preferably, the second arc end of the inner wire hook is at a distance from the ring portion of the outer wire hook, and the inner wire portion is spanned between the second arc end and the ring portion.

[0012] Preferably, the inner wire hook portion of the inner wire hook member is axially spaced a distance from the outer wire hook portion of the outer wire hook member, and when the outer wire cutter is at the second cutting position, the outer wire blade portion is located between the inner wire hook portion and the outer wire hook portion.

[0013] Preferably, when the outer thread cutter is at the second thread cutting position and the outer thread hook moves the outer thread to the outer thread cutting position, the outer thread is located below the outer thread blade portion.

[0014] Preferably, the cutting unit also has a first pressure cylinder and a second pressure cylinder, the first pressure cylinder is fixed to the rocker unit and is connected to drive the inner wire cutter to move between a first initial position and a first cutting position, and the second pressure cylinder is fixed to the rocker unit and is connected to drive the outer wire cutter to move between a second initial position and a second cutting position.

[0015] Preferably, the inner wire cutting tool has a first inner blade segment connected to the first pressure cylinder, and a second inner blade segment connected between the first inner blade segment and the inner wire blade portion and bent at an angle to the first inner blade segment; the outer wire cutting tool has a first outer blade segment connected to the second pressure cylinder, and a second outer blade segment connected between the first outer blade segment and the outer wire blade portion and bent at an angle to the first outer blade segment; the cutting unit also has a first cutting knife guide seat and a second cutting knife guide seat; the first cutting knife guide seat is fixedly mounted on the rocker arm unit, and has a first inner blade guide groove for the first inner blade segment and a first outer blade guide groove for the first outer blade segment; the second cutting knife guide seat is fixedly mounted on the rocker arm unit, and has a second inner blade guide groove for the second inner blade segment and a second outer blade guide groove for the second outer blade segment.

[0016] Preferably, the second inner blade segment of the inner wire cutting knife and the second outer blade segment of the outer wire cutting knife are both flexible.

[0017] Preferably, the inner wire cutting blade of the inner wire cutting knife is V-shaped, and the outer wire cutting blade of the outer wire cutting knife is arc-shaped. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional combination diagram of an embodiment of the present invention;

[0019] Figure 2A is a partial cross-sectional view of an embodiment of the present invention, showing the state of the wire-tightening unit in the release position;

[0020] Figure 2B is a partial cross-sectional view of an embodiment of the present invention, showing the state of the wire-tightening unit in a tightening position;

[0021] Figure 3 It is a partial three-dimensional composite diagram of an embodiment of the present invention;

[0022] Figure 4 is a partial three-dimensional exploded view of an embodiment of the present invention;

[0023] Figure 5 is a partial three-dimensional exploded view of another viewing angle of an embodiment of the present invention;

[0024] Figure 6 is a schematic diagram of the operation of an embodiment of the present invention, showing the state of the inner line hook in the original position;

[0025] Fig. 7A is an actuation schematic diagram of an embodiment of the present invention, showing a state in which the inner wire hook member hooks the inner wire to an inner wire cutting position;

[0026] Figure 7B is a schematic side view of the embodiment of the present invention in operation, showing a state where the inner wire hook member hooks the inner wire to an inner wire cutting position;

[0027] Figure 7C is a schematic diagram of the operation of an embodiment of the present invention, showing the state where the inner thread cutter rises from a first initial position to a first cutting position;

[0028] Fig. 8A is an operation schematic diagram of an embodiment of the present invention, showing a state in which the outer thread hook member hooks the outer thread to the outer thread cutting preparation position, and the outer thread cutter rises from the second initial position to the second thread cutting position;

[0029] Figure 8B yes Fig. 8A Stereoscopic image of

[0030] Figure 8C is an operation schematic diagram of an embodiment of the present invention, showing a state where the outer line hook member hooks the outer line to an outer line cutting position; and

[0031] Fig.8D It is a schematic side view of the embodiment of the present invention, showing the state where the outer thread cutting knife descends from the second cutting position to the second initial position.

[0032] Description of symbols in the accompanying drawings:

[0033] 10…Body

[0034] 11…Head unit

[0035] 12…Transmission unit

[0036] 13…Pendulum drive

[0037] 14…Needle bar

[0038] 15…Presser foot

[0039] 20…Wire tensioning unit

[0040] 21…Wire tensioner

[0041] 211…Stretching Space

[0042] 22…Wire tensioning cylinder

[0043] 221…Wire tensioning cylinder

[0044] 222…Wire tensioning piston rod

[0045] 23…Wire tensioning block

[0046] 231…Wire perforation

[0047] 30…Rocker arm unit

[0048] 100…Hook line unit

[0049] 40…Hook wire seat

[0050] 41…First hook line housing

[0051] 42…Second hook wire housing

[0052] 43…Needle plate

[0053] 50…External hook

[0054] 51…Ring

[0055] 52… Accommodation space

[0056] 53…Ring groove

[0057] 54…Outside hook

[0058] 60…Hook

[0059] 70…Inner line hook

[0060] 71…The driven department

[0061] 72…Inner line hook

[0062] 721…First arc end

[0063] 722…Second arc end

[0064] 723…Arc groove

[0065] 80…Tangent unit

[0066] 81…Inner thread cutter

[0067] 811…Inner blade

[0068] 812…First inner blade segment

[0069] 813…Second inner blade segment

[0070] 82…External line cutter

[0071] 821…Outside blade

[0072] 822…First outer blade segment

[0073] 823…Second outer blade segment

[0074] 83…First cylinder

[0075] 84…Second pressure cylinder

[0076] 85…First cutter guide seat

[0077] 851…First inner knife guide groove

[0078] 852…First outer knife guide groove

[0079] 86…Second cutter guide seat

[0080] 861…Second inner knife guide groove

[0081] 862…Second outer knife guide groove

[0082] 87…First guide cover

[0083] 88…Second guide cover

[0084] 91…Things to be sewn

[0085] 95…External

[0086] 97…Inside

[0087] X…Axial DETAILED DESCRIPTION

[0088] Before presenting a detailed description, it should be noted that in the following description, similar components and part names are represented by the same number, and the directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used in the embodiments are used to illustrate and are not used to limit the present invention.

[0089] See also Figures 1 to 6 As shown, a sewing machine with an automatic thread trimming device provided in an embodiment of the present invention is suitable for sewing a to-be-sewn object 91. The sewing machine with an automatic thread trimming device is composed of a machine body 10, a thread stretching unit 20, a rocker unit 30, a thread hooking unit 100, and a thread cutting unit 80, wherein:

[0090] The machine body 10 is fixed on a base (not shown) and is provided with a head device 11, a transmission unit 12, a pendulum transmission device 13, a needle bar 14 for an outer thread 95 to pass through, a presser foot 15, etc. Since the various devices or parts on the machine body 10 are all conventional components and their operating methods are the same as those of the conventional ones, and are not the focus of the invention, the detailed structures and operating methods of these components are not described in detail.

[0091] Related References Figure 2A and Figure 2B As shown, the wire-tightening unit 20 is disposed on the body 10 and is provided with an outer wire 95 for passing through. The wire-tightening unit 20 can be in a tightening position (such as Figure 2B ) and a release position (such as Figure 2A) between the two, when the wire-tensioning unit 20 is in the tightening position, the wire-tensioning unit 20 tightens the outer wire 95, and when the wire-tensioning unit 20 is in the releasing position, the wire-tensioning unit 20 releases the outer wire 95; in this embodiment, the wire-tensioning unit 20 includes a wire-tensioning seat 21, a wire-tensioning cylinder 22 and a wire-tensioning block 23; the wire-tensioning seat 21 is fixedly mounted on the machine body 10 and has a wire-tensioning space 211, the wire-tensioning cylinder 22 has a wire-tensioning cylinder body 221 fixedly mounted on the wire-tensioning seat 21, and a wire-tensioning cylinder body 221 and capable of being in the tightening position (such as Figure 2B ) and the release position (such as Figure 2A ) between the wire-tensioning piston rod 222; the wire-tensioning block 23 is fixedly mounted on the wire-tensioning piston rod 222, and has a wire-tensioning through hole 231 for the outer wire 95 to pass through. When the wire-tensioning unit 20 is in the tightening position, the wire-tensioning piston rod 222 brings the wire-tensioning block 23 to the wire-tensioning space 211, so that the outer wire 95 is clamped between the wire-tensioning block 23 and the wire-tensioning seat 21. When the wire-tensioning unit 20 is in the releasing position, the wire-tensioning piston rod 222 brings the wire-tensioning block 23 away from the wire-tensioning space 211, so that the outer wire 95 is not clamped by the wire-tensioning block 23 and the wire-tensioning seat 21.

[0092] The rocker unit 30 is pivotally mounted on the body 10 . The rocker unit 30 is a conventional component, and its actuation is the same as the conventional one, and is not the focus of the invention. Therefore, the detailed structure and actuation of the component will not be described in detail.

[0093] Related References Figures 3 to 6 As shown, the thread hooking unit 100 is disposed on the rocker unit 30 and includes a thread hooking seat 40, an outer thread hook 50, a rotary hook 60, and an inner thread hook 70;

[0094] The thread hooking seat 40 is fixed on the rocker unit 30 and is used for the outer thread 95 to pass through. In this embodiment, the thread hooking seat 40 is composed of a first thread hooking housing 41 and a second thread hooking housing 42, and a needle plate 43 is provided above the second thread hooking housing 42 for the needle bar 14 to pass through.

[0095] The outer line hook 50 can be in an outer line cutting preparation position (such as Fig. 8A ) and an external line cut-off position (such as Figure 8C ) is rotatably disposed in the thread hook seat 40 and has an outer thread hook portion 54 for hooking the outer thread 95; in this embodiment, the outer thread hook member 50 has a ring portion 51, a receiving space 52 surrounded by the ring portion 51 and for receiving the rotary hook 60, a ring groove 53 recessed around the ring portion 51 and for receiving part of the inner thread 97, and the outer thread hook portion 54 disposed on the ring portion 51;

[0096] The rotary hook 60 is disposed in the accommodating space 52 of the outer thread hook 50, so as to be eccentrically rotatable in the thread hook seat 40, and the rotary hook 60 provides an inner thread 97 (such as Figure 6 ); The rotary shuttle 60 is a conventional component, and its actuation mode is the same as the conventional one, and is not the focus of the invention, so the detailed structure and actuation mode of the component are not described in detail.

[0097] The inner wire hook 70 is rotatably disposed in the wire hook seat 40 and has a function of moving the inner wire 97 from its original position (such as Figure 6 ) to an inner line cutting position (such as Fig. 7A ) of the inner line hook portion 72; in this embodiment, the inner line hook member 70, the rotary shuttle 60 and the outer line hook member 50 rotate synchronously. In this embodiment, the inner line hook member 70, the rotary shuttle 60 and the outer line hook member 50 are driven by a servo system (not shown in the figure), but not limited to this. At the same time, the inner line hook member 70 has a driven portion 71, an inner line hook portion 72 provided on the driven portion 71, and the inner line hook portion 72 is arc-shaped and has a first arc end 721, a second arc end 722 opposite to the first arc end 721, and an arc-shaped groove 723 concavely provided between the first arc end 721 and the second arc end 722. When the inner line hook member 70 hooks the inner line 97 to the inner line cutting position (such as Fig. 7A ), the inner wire 97 is partially located in the annular groove 53 of the outer wire hook 50, and the inner wire 97 is partially located in the arc groove 723 of the inner wire hook 70, and the second arc end 722 of the inner wire hook 70 is separated from the ring portion 51 of the outer wire hook 50 by a distance in the axial direction X, and the inner wire 97 is partially straddled between the second arc end 722 and the ring portion 51 (such as Figure 7B ).

[0098] The cutting unit 80 is disposed on the rocker unit 30 and includes an inner cutting knife 81 and an outer cutting knife 82. The inner cutting knife 81 can be in a first initial position (such as Fig. 7A ) and a first tangent position (such as Figure 7C ) is movably disposed on the rocker arm unit 30 and has an inner wire blade portion 811 for cutting the inner wire 97. In this embodiment, the inner wire blade portion 811 of the inner wire cutter 81 is V-shaped, and the blade edge of the inner wire blade portion 811 faces upward; see FIG. Figure 7C As shown, when the inner wire hook 70 hooks the inner wire 97 to the inner wire cutting position and the inner wire cutter 81 is at the first cutting position, the inner wire blade 811 cuts the inner wire 97; the outer wire cutter 82 can be at a second initial position (such as Figure 6 ) and a second tangent position (such as Fig. 8A) is movably disposed on the rocker arm unit 30 and has an outer wire cutting blade portion 821 for cutting the outer wire 95. In this embodiment, the outer wire cutting blade portion 821 of the outer wire cutting knife 82 is arc-shaped, and the blade of the outer wire cutting blade portion 821 faces downward; when the outer wire cutting knife 82 is at the second cutting position (such as Figure 8C ), and the outer line hook 50 hooks the outer line 95 to the outer line cutting position (such as Figure 8C ), and the wire-tightening unit 20 is in the tightening position (such as Figure 2A ), the outer thread cutter 82 is controlled to move from the second cutting position to the second initial position (such as Fig.8D ), the outer wire blade 821 cuts the outer wire 95; in this embodiment, the cutting unit 80 also has a first pressure cylinder 83 and a second pressure cylinder 84, the first pressure cylinder 83 is fixedly installed on the rocker unit 30 and is connected to drive the inner wire cutter 81 to move between the first initial position and the first cutting position, the second pressure cylinder 84 is fixedly installed on the rocker unit 30 and is connected to drive the outer wire cutter 82 to move between the second initial position and the second cutting position; the inner wire cutter 81 has a first pressure cylinder 83 connected to the first pressure cylinder 84. The outer cutter 82 comprises a first inner cutter segment 822 connected to the second pressure cylinder 84, a second inner cutter segment 822 connected to the outer cutter segment 821 and bent at an angle to the first outer cutter segment 822, and a first inner cutter segment 813 connected between the first inner cutter segment 812 and the inner cutter blade portion 811 and bent at an angle to the first inner cutter segment 812. In this embodiment, the second inner cutter segment 813 of the inner cutter 81 is flexible; the outer cutter 82 comprises a first outer cutter segment 822 connected to the second pressure cylinder 84, a second inner cutter segment 813 connected between the first inner cutter segment 812 and the inner cutter blade portion 811 and bent at an angle to the first outer cutter segment 822. The outer blade segment 823, in this embodiment, the second outer blade segment 823 of the outer blade 82 is flexible; the cutting unit 80 also has a first blade guide seat 85 and a second blade guide seat 86; the first blade guide seat 85 is fixed to the rocker unit 30, and has a first inner blade guide groove 851 for the first inner blade segment 812 and a first outer blade guide groove 852 for the first outer blade segment 822, and is covered by a first guide cover 87 on the first blade guide seat 85 to prevent the inner thread cutter 81 and the outer thread cutter 82 from detaching from the first cutter guide seat 85; the second cutter guide seat 86 is fixedly mounted on the rocker unit 30, and has a second inner knife guide groove 861 for the second inner knife segment 813 and a second outer knife guide groove 862 for the second outer knife segment 823. At the same time, a second guide cover 88 is covered on the second cutter guide seat 86 to prevent the inner thread cutter 81 and the outer thread cutter 82 from detaching from the second cutter guide seat 86.

[0099] It is worth noting that, see Figure 8BAs shown in FIG. 1 , the inner wire hook portion 72 of the inner wire hook member 70 and the outer wire hook portion 54 of the outer wire hook member 50 are spaced apart from each other in the axial direction X. When the outer wire cutter 82 is at the second cutting position, the outer wire blade 821 is located between the inner wire hook portion 72 and the outer wire hook portion 54. In addition, when the outer wire cutter 82 is at the second cutting position and the outer wire hook member 50 hooks the outer wire 95 to the outer wire cutting position, the outer wire 95 is located below the outer wire blade 821 (as shown in FIG. 1 ). Figure 8C ).

[0100] The above is the configuration description of each major component of the embodiment of the present invention. The operation mode and effect of the present invention are described as follows.

[0101] Internal line automatic cut-off: The following instructions only show the internal line.

[0102] First, the operator triggers the automatic thread trimming device to operate. Figure 6 As shown, the needle bar 14 automatically returns to the origin, the inner thread hook 70 automatically rotates to the origin, and the inner thread cutter 81 is at the first initial position. At this time, one end of the inner thread 97 is sewn on the object to be sewn 91, and the other end of the inner thread 97 is inside the rotary hook 60.

[0103] See also Fig. 7A and Figure 7B As shown, the inner thread hook 70 then automatically rotates 360 degrees clockwise, allowing the inner thread hook 70 to hook the inner thread 97 to the inner thread cutting position. At this time, the inner thread hook 70 hooks the inner thread 97 through the inner thread hook portion 72, and the inner thread 97 is output by the rotary shuttle 60, so that a portion of the inner thread 97 is located in the annular groove 53 of the outer thread hook 50, and a portion of the inner thread 97 is located in the arc groove 723 of the inner thread hook 70, and a portion of the inner thread 97 is placed between the second arc end 722 of the inner thread hook 70 and the ring portion 51 of the outer thread hook 50. At this time, the portion of the inner thread 97 is located above the inner thread blade portion 811 of the inner thread cutter 81 and within the rising stroke range of the inner thread cutter 81.

[0104] See also Figure 7C As shown, the inner thread cutter 81 then automatically rises, that is, the inner thread cutter 81 moves from the first initial position (such as Fig. 7A ) rises to the first tangent position (such as Figure 7C ), the inner wire cutter 81 after rising cuts the inner wire 97 by means of the V-shaped inner wire blade 811, thereby completing the automatic cutting operation of the inner wire 97; then the inner wire cutter 81 is automatically controlled to descend back to the first initial position to wait for the automatic cutting operation of the outer wire to be performed.

[0105] Automatic disconnection of external lines: The following instructions show only external lines.

[0106] It should be explained first that one end of the outer thread 95 is interwoven with the inner thread 97 and sewn onto the object to be sewn 91, and the other end of the outer thread 95 passes through the interior of the thread hook seat 40 and then passes out, and sequentially passes through the needle bar 14 and the thread through hole 231 of the thread tensioning unit 20, and is finally wound around the sewing thread seat (not shown in the figure).

[0107] See also Fig. 8A and Figure 8B As shown, the outer thread hook 50 is controlled to rotate counterclockwise by an angle, so that the outer thread hook 50 brings the outer thread 95 to the outer thread cutting preparation position through the outer thread hook portion 54, and at the same time controls the outer thread cutter 82 to rise from the second initial position to the second cutting position.

[0108] See also Figure 8C As shown, the outer wire hook 50 is controlled to rotate counterclockwise by an angle, so that the outer wire hook 50 brings the outer wire 95 to the outer wire cutting position through the outer wire hook portion 54. At this time, the outer wire 95 is partially located below the outer wire blade portion 821 of the outer wire cutter 82 and within the descending stroke range of the outer wire cutter 82.

[0109] See also Figure 2A and Figure 2B As shown, the wire tensioning unit 20 is then controlled to move from the release position to the tightening position, so that the outer wire 95 is clamped between the wire tensioning block 23 and the wire tensioning seat 21. At this time, the outer wire 95 is not only located below the outer wire blade portion 821 of the outer wire cutter 82, but is also in a tightened state.

[0110] See also Fig.8D As shown, the outer thread cutter 82 is then controlled to automatically rise downward, that is, the outer thread cutter 82 is moved from the second cutting position (such as Figure 8C ) drops to the second initial position (such as Fig.8D ), the outer wire cutter 82 after being lowered cuts off the outer wire 95 by means of the arc-shaped outer wire blade portion 821, thereby completing the automatic cutting operation of the outer wire 95; then the wire hooking unit 100 is automatically controlled to return to the origin and the wire stretching unit 20 is automatically controlled to return to the release position to release the outer wire 95, thereby completing the automatic cutting operation of the inner wire 97 and the outer wire 95.

[0111] Accordingly, the present invention can automatically cut off the inner thread 97 by the rotational action of the inner thread hook 70 of the thread hook unit 100 and the telescopic action of the inner thread cutter 81 of the thread cutting unit 80; in addition, the outer thread 95 can be automatically cut off by the action of the thread tensioning unit 20 to tighten the outer thread 95, the rotational action of the outer thread hook 50 of the thread hook unit 100, and the telescopic action of the outer thread cutter 82 of the thread cutting unit 80, thereby avoiding interruption of sewing operation, effectively saving sewing operation time and improving work efficiency.

[0112] It is worth mentioning that the present invention specifically designs the inner wire blade portion 811 of the inner wire cutter 81 to be V-shaped, and the blade edge of the inner wire blade portion 811 faces upward and toward the inner wire 97. Therefore, when the inner wire cutter 81 moves from bottom to top, the inner wire 97 will be guided and restricted by the V-shaped inner wire blade portion 811 to ensure that the inner wire 97 can be cut by the inner wire cutter 81.

[0113] Similarly, the present invention specifically designs the outer wire blade portion 821 of the outer wire cutter 82 to be arc-shaped, and the blade edge of the outer wire blade portion 821 faces downward and toward the outer wire 95. Therefore, when the outer wire cutter 82 moves from top to bottom, the outer wire 95 will be guided and restricted by the arc-shaped outer wire blade portion 821 to ensure that the outer wire 95 can be cut by the outer wire cutter 82.

Claims

1. A sewing machine with an automatic thread trimming device, characterized in that: The sewing machine with automatic thread cutting device comprises: One organism; a wire-tightening unit, disposed on the machine body and allowing an external wire to pass through, the wire-tightening unit being able to move between a tightening position and a releasing position, when the wire-tightening unit is in the tightening position, the wire-tightening unit tightens the external wire, and when the wire-tightening unit is in the releasing position, the wire-tightening unit releases the external wire; A rocker unit, pivotally mounted on the machine body; A thread hooking unit is arranged on the rocker unit, and comprises a thread hooking seat, an outer thread hook, a rotary shuttle, and an inner thread hook; the thread hooking seat is fixed on the rocker unit, and the outer thread is passed through; the outer thread hook can be rotatably arranged in the thread hooking seat between an outer thread cutting preparation position and an outer thread cutting position, and has an outer thread hook part for hooking the outer thread; the rotary shuttle can be eccentrically rotatably arranged in the thread hooking seat, and provides an inner thread; the inner thread hook can be rotatably arranged in the thread hooking seat, and has an inner thread hook part for hooking the inner thread to an inner thread cutting position; as well as A cutting unit, which is arranged on the rocker unit and includes an inner cutting knife and an outer cutting knife; The inner thread cutter can be movably arranged on the rocker unit between a first initial position and a first tangent position, and has an inner thread blade portion for cutting the inner thread. When the inner thread hook hooks the inner thread to the inner thread cutting position and the inner thread cutter is at the first tangent position, the inner thread blade portion cuts the inner thread; the outer thread cutter can be movably arranged on the rocker unit between a second initial position and a second tangent position, and has an outer thread blade portion for cutting the outer thread. When the outer thread cutter is at the second tangent position, the outer thread hook hooks the outer thread to the outer thread cutting position, and the tensioning unit is at the tightening position, the outer thread cutter is controlled to be actuated from the second tangent position to the second initial position, and the outer thread blade portion cuts the outer thread.

2. The sewing machine with automatic thread trimming device according to claim 1, characterized in that: The wire-tensioning unit includes a wire-tensioning seat, a wire-tensioning pressure cylinder and a wire-tensioning block; the wire-tensioning seat is fixedly mounted on the machine body and has a wire-tensioning space, the wire-tensioning pressure cylinder has a wire-tensioning cylinder body fixedly mounted on the wire-tensioning seat, and a wire-tensioning piston rod arranged on the wire-tensioning cylinder body and capable of moving between the tightening position and the releasing position; the wire-tensioning block is fixedly mounted on the wire-tensioning piston rod and has a wire-tensioning through hole for the outer wire to pass through, when the wire-tensioning unit is in the tightening position, the wire-tensioning piston rod brings the wire-tensioning block to the wire-tensioning space so that the outer wire is clamped between the wire-tensioning block and the wire-tensioning seat, and when the wire-tensioning unit is in the releasing position, the wire-tensioning piston rod brings the wire-tensioning block away from the wire-tensioning space so that the outer wire is not clamped by the wire-tensioning block and the wire-tensioning seat.

3. The sewing machine with automatic thread trimming device according to claim 1, characterized in that: The outer thread hook has a ring portion, a containing space surrounded by the ring portion and for containing the rotary hook, a ring groove recessed around the ring portion and for part of the inner thread to be arranged, and the outer thread hook portion arranged on the ring portion.

4. The sewing machine with automatic thread trimming device according to claim 3, characterized in that: The inner wire hook has a driven portion and an inner wire hook portion arranged on the driven portion, the inner wire hook portion is arc-shaped and has a first arc end, a second arc end opposite to the first arc end, and an arc-shaped groove recessed between the first arc end and the second arc end, when the inner wire hook hooks the inner wire to the inner wire cutting position, the inner wire portion is located in the annular groove of the outer wire hook, and the inner wire portion is located in the arc-shaped groove of the inner wire hook.

5. The sewing machine with automatic thread trimming device according to claim 4, characterized in that: The second arc end of the inner line hook is at a distance from the ring portion of the outer line hook, and the inner line portion is spanned between the second arc end and the ring portion.

6. The sewing machine with automatic thread trimming device according to claim 1, characterized in that: The inner wire hook portion of the inner wire hook member is axially spaced a distance from the outer wire hook portion of the outer wire hook member; when the outer wire cutter is at the second tangent position, the outer wire blade portion is located between the inner wire hook portion and the outer wire hook portion; when the outer wire cutter is at the second tangent position and the outer wire hook member hooks the outer wire to the outer wire cutting position, the outer wire is located below the outer wire blade portion.

7. The sewing machine with automatic thread trimming device according to claim 1, characterized in that: The cutting unit also has a first pressure cylinder and a second pressure cylinder. The first pressure cylinder is fixedly arranged on the rocker unit and is connected to drive the inner wire cutter to move between a first initial position and a first cutting position. The second pressure cylinder is fixedly arranged on the rocker unit and is connected to drive the outer wire cutter to move between a second initial position and a second cutting position.

8. The sewing machine with automatic thread trimming device according to claim 7, characterized in that: The inner wire cutting tool has a first inner blade segment connected to the first pressure cylinder, and a second inner blade segment connected between the first inner blade segment and the inner wire blade portion and bent at an angle to the first inner blade segment; the outer wire cutting tool has a first outer blade segment connected to the second pressure cylinder, and a second outer blade segment connected between the first outer blade segment and the outer wire blade portion and bent at an angle to the first outer blade segment; the cutting unit also has a first cutting knife guide seat and a second cutting knife guide seat; the first cutting knife guide seat is fixedly mounted on the rocker arm unit, and has a first inner blade guide groove for setting the first inner blade segment and a first outer blade guide groove for setting the first outer blade segment; the second cutting knife guide seat is fixedly mounted on the rocker arm unit, and has a second inner blade guide groove for setting the second inner blade segment and a second outer blade guide groove for setting the second outer blade segment.

9. The sewing machine with automatic thread trimming device according to claim 8, characterized in that: The second inner blade segment of the inner wire cutting knife and the second outer blade segment of the outer wire cutting knife are both flexible.

10. The sewing machine with automatic thread trimming device according to claim 1, characterized in that: The inner wire cutting blade of the inner wire cutting knife is V-shaped, and the outer wire cutting blade of the outer wire cutting knife is arc-shaped.

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