Sewing machine

Abstract

In a two-needle sewing machine using a semi-rotating kettle, the interval between two sewing machine needles is close to each other. The sewing machine includes: a needle bar that holds a sewing machine needle on which an upper thread is hung and reciprocates in an up-down direction; a needle plate disposed below the needle rod and having a needle hole into which a sewing machine needle is inserted; a kettle which is disposed below the needle plate and supplies the lower line; and a thread cutting device that cuts the upper thread and the lower thread in a state where the sewing machine needle is disposed above the needle plate. The thread cutting device is provided with a fixed cutter which is fixed on the lower surface of the needle plate; the movable cutter can rotate between a standby position and an in-out position with a pivot shaft arranged on the lower surface of the needle plate as the center. The movable cutter is provided with a processing part, and the processing part enters an upper thread ring formed below the needle hole by rotating towards the in-out position so as to divide the upper thread ring into a needle side part and a stitch side part. The processing part enters the upper thread ring in a manner that the needle side part is arranged closer to the radial outer side of the pivot than the stitch side part and the lower thread.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a sewing machine. Background Art

[0002] In the technical field of sewing machines, a sewing machine with a thread cutting device as disclosed in Patent Document 1 is known.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-236280 Summary of the Invention

[0006] (1) Technical issues to be resolved

[0007] The thread cutting device of a sewing machine has a fixed cutter and a movable cutter. When cutting the upper thread and the lower thread, the upper thread and the lower thread extending downward from the needle hole of the needle plate are hooked by the movable cutter. After hooking the upper thread and the lower thread, the movable cutter rotates so as to be close to the fixed cutter, thereby cutting the upper thread and the lower thread. In the thread cutting device of a sewing machine using a semi-rotating kettle as in Patent Document 1, the structure is as follows: Figure 1 When looking from the left (front) of the Figure 7 (a) to Figure 8 As shown in (e), the movable cutter moves from the front, enters the loop of the needle thread, and cuts both the needle and the lower thread as it reverses and returns. Therefore, space is required on the front side of the kettle to accommodate the movable cutter and the fixed cutter. Furthermore, in a double-needle sewing machine where the semi-rotating kettles are positioned opposite each other, the movable cutter and the fixed cutter are placed between the kettles, making it impossible to bring the two kettles closer together. This inevitably makes it difficult to close the gap between the two sewing machine needles.

[0008] The purpose of the technology disclosed in this specification is to reduce the distance between two sewing machine needles in a double-needle sewing machine using a semi-rotary kettle.

[0009] (2) Technical solution

[0010] This specification discloses a sewing machine. The sewing machine includes: a needle bar that holds a sewing needle with an upper thread suspended thereon and reciprocates in the vertical direction; a needle plate that is disposed below the needle bar and has a needle hole into which the sewing needle is inserted; a bobbin that is disposed below the needle plate and supplies a lower thread; and a thread cutting device that cuts the upper thread and the lower thread in a state where the sewing needle is disposed above the needle plate. The thread cutting device has: a fixed cutter that is fixed to the lower surface of the needle plate; and a movable cutter that can rotate between a standby position and an advancing / retreating position about a pivot provided on the lower surface of the needle plate. The movable cutter has a processing portion (Japanese: 捌き部), and by rotating toward the advancing / retreating position, the processing portion enters an upper thread loop formed below the needle hole and divides the upper thread loop into a needle-side portion and a stitch-side portion. The processing portion enters the upper thread loop such that the needle-side portion is disposed radially outside the pivot relative to the stitch-side portion and the lower thread.

[0011] (III) Advantageous Effects

[0012] According to the technology disclosed in this specification, it is possible to reduce the distance between two sewing needles in a double-needle sewing machine using a semi-rotary bobbin. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a perspective view of the sewing machine according to the embodiment.

[0014] Figure 2 is a diagram for explaining the operation of the semi-rotary bobbin according to the embodiment.

[0015] Figure 3 is a diagram for explaining the operation of the semi-rotary bobbin according to the embodiment.

[0016] Figure 4 is a diagram for explaining the operation of the semi-rotary bobbin according to the embodiment.

[0017] Figure 5 is a diagram for explaining the operation of the semi-rotary bobbin according to the embodiment.

[0018] Figure 6 is a perspective view of the thread cutting device according to the embodiment as viewed from above.

[0019] Figure 7 is a view of the thread cutting device according to the embodiment as viewed from the right.

[0020] Figure 8 is a view of the thread cutting device according to the embodiment as viewed from below. [[ID=4l]]

[0021] Figure 9 is a perspective view of the movable cutter according to the embodiment as viewed from above.

[0022] Figure 10 is a diagram showing the operation of the movable cutter according to the embodiment.

[0023] Figure 11 This is a perspective view for explaining the operation of the movable knife according to the embodiment.

[0024] Figure 12 This is a diagram showing the thread cutting device according to the embodiment as viewed from below.

[0025] Figure 13 This is a diagram showing the thread cutting device according to the embodiment as viewed from below.

[0026] Figure 14 This is a diagram showing the thread cutting device according to the embodiment as viewed from below.

[0027] Figure 15 This is a diagram for explaining the effects of the thread cutting device according to the embodiment.

[0028] Description of reference numerals:

[0029] 1: Sewing machine; 2: Sewing machine table; 3: Sewing machine frame; 4: Sewing machine needle; 4A: Threading hole; 5: Needle bar; 6: Thread take-up lever; 7: Needle plate; 7A: Needle hole; 7B: Pivot; 8: Presser foot; 9: Thread regulator; 10: Semi-rotating kettle; 10A: Tip; 11: Spool box; 20: Thread trimmer; 21: Fixed cutter; 21A: Main body; 21B: Blade; 22: Movable cutter; 22A: Main body; 22B: Bending section; 22C: Processing section; 22 D: Rotation hole; 22E: Tip portion; 22F: Blade portion; 22G: First guide portion; 22H: Second guide portion; 22J: First recess; 22K: Second recess; 22L: Pin hole; 23: Elastic component; 24: Screw; 25: Rotation pin; 26: Operating lever; 50: Upper thread; 51: Upper thread ring; 51A: Needle side portion; 51B: Stitch side portion; 60: Lower thread; 100: Fabric; 101: Stitch; Pa: Standby position; Pb: In and out position. DETAILED DESCRIPTION

[0030] The following describes the embodiment with reference to the accompanying drawings. In the embodiment, the terms left, right, front, back, top, and bottom are used to describe the positional relationship of each part. These terms represent relative positions or directions based on the operator operating the sewing machine 1.

[0031] [Sewing machine]

[0032] Figure 1 This is a perspective view of a sewing machine 1 according to an embodiment. In the embodiment, the sewing machine 1 is an industrial sewing machine. It is a double-needle, semi-rotary, lockstitch sewing machine. The sewing machine 1 includes a sewing machine frame 3, a needle bar 5, a thread take-up lever 6, a needle plate 7, and a presser foot 8.

[0033] The sewing machine frame 3 is provided on the upper surface of the sewing machine table 2. An operator operates the sewing machine 1 from the front side of the sewing machine table 2.

[0034] The needle bar 5 holds the sewing needle 4, to which the needle thread 50 is attached, and reciprocates in the vertical direction. The needle bar 5 is supported by the sewing machine frame 3. Two sewing needles 4 are provided. The needle bar 5 holds the two sewing needles 4. The two sewing needles 4 are arranged in the front-to-back direction. The sewing needle 4 has a threading hole 4A through which the needle thread 50 passes. The sewing needle 4 holds the needle thread 50 on the inner surface of the threading hole 4A. As the needle bar 5 reciprocates in the vertical direction, the sewing needle 4 reciprocates in the vertical direction while holding the needle thread 50.

[0035] The thread take-up lever 6 supplies the needle thread 50 to the sewing machine needle 4. The thread take-up lever 6 reciprocates vertically. The thread take-up lever 6 is supported by the sewing machine frame 3. The thread take-up lever 6 reciprocates vertically while holding the needle thread 50. The thread take-up lever 6 has a retaining hole through which the needle thread 50 passes. The thread take-up lever 6 retains the needle thread 50 on the inner surface of the retaining hole. The thread take-up lever 6 reciprocates vertically to feed the needle thread 50 used for sewing the fabric 100 or to pick up the needle thread 50.

[0036] The needle plate 7 supports the fabric 100 from below. The needle plate 7 is positioned below the needle bar 5. The sewing machine needle 4, held by the needle bar 5, faces the needle plate 7. Two needle plates 7 are provided, corresponding to the two sewing machine needles 4. The two needle plates 7 are arranged in the front-to-back direction. The needle plate 7 has a needle hole 7A for inserting the sewing machine needle 4. The sewing machine needle 4, which penetrates the fabric 100 supported by the needle plate 7, is inserted into the needle hole 7A.

[0037] The presser foot 8 presses the fabric 100 supported by the needle plate 7 from above. The presser foot 8 is positioned around at least a portion of the sewing machine needle 4. Two presser feet 8 are provided, corresponding to the two sewing machine needles 4. The two presser feet 8 are arranged along the front-to-back direction. The presser foot 8 is supported by the sewing machine frame 3. The presser foot 8 is movable in the vertical direction, the front-to-back direction, and the left-to-right direction.

[0038] The sewing machine 1 also includes a feed device that moves the fabric 100 in the front-to-back and left-to-right directions. The feed device includes a lower plate (not shown) that clamps the fabric 100 and a presser foot 8. The lower plate is positioned below the fabric 100, and the presser foot 8 is positioned above the fabric 100. The lower plate clamps the fabric 100 from below, and the presser foot 8 clamps the fabric 100 from above. The feed device forms a predetermined stitch on the fabric 100 by moving the fabric 100 in the front-to-back and left-to-right directions.

[0039] [Semi-rotating kettle]

[0040] Figure 2 、 Figure 3 、 Figure 4as well as Figure 5 Each of these is a diagram for explaining the operation of the semi-rotary kettle 10 according to the embodiment. Figure 2 、 Figure 3 、 Figure 4 as well as Figure 5 Each of these diagrams shows the semi-rotary kettle 10 as viewed from the front (operator's side). The sewing machine 1 includes the semi-rotary kettle 10, which is positioned below the needle plate 7. The semi-rotary kettle 10 supplies the bobbin thread 60. The semi-rotary kettle 10 is positioned directly below the sewing needle 4. Two semi-rotary kettles 10 are provided, corresponding to the two sewing needles 4. The two semi-rotary kettles 10 are arranged in the front-to-back direction. The two semi-rotary kettles 10 are positioned so as to face each other.

[0041] The semi-rotating kettle 10 has a tip 10A that catches the needle thread 50 from the lowered sewing machine needle 4. The semi-rotating kettle 10 houses a bobbin case 11. The bobbin case 11 houses the bobbin. The bobbin is wound around the bobbin. The semi-rotating kettle 10 reciprocates approximately half a revolution. For every one vertical reciprocating movement of the sewing machine needle 4, the semi-rotating kettle 10 reciprocates once. In the following description, a half-revolution of the semi-rotating kettle 10 in the forward direction is referred to as a forward rotation, and a half-revolution of the semi-rotating kettle 10 in the reverse direction is referred to as a return rotation.

[0042] like Figure 2 As shown, when the sewing machine needle 4 descends and penetrates the cloth 100, a loop of the needle thread 50 is formed below the cloth 100. The semi-rotating kettle 10 rotates in the forward direction so as to hook the loop of the needle thread 50 with the tip 10A.

[0043] like Figure 3 As shown, when the semi-rotary kettle 10 rotates forward and the sewing machine needle 4 rises and separates from the fabric 100, the loop of the needle thread 50 becomes larger. Furthermore, the forward rotation of the semi-rotary kettle 10 causes the needle thread 50 to move along the outer circumference of the spool box 11. In the following description, the loop of the needle thread 50 formed below the fabric 100 after the sewing machine needle 4 has risen and separated from the fabric 100 will be appropriately referred to as the needle thread loop 51.

[0044] Upper thread loop 51 is formed from stitch 101 formed on cloth 100 to threading hole 4A of sewing machine needle 4. Upper thread loop 51 includes needle side portion 51A between threading hole 4A and tip 10A and stitch side portion 51B between tip 10A and stitch 101.

[0045] like Figure 4 As shown, after the semi-rotating kettle 10 finishes its forward rotation and the upper thread loop 51 passes through the outer periphery of the spool box 11, the upper thread 50 is picked up by the thread take-up rod 6, thereby releasing the upper thread 50 from the tip 10A and winding the upper thread 50 with the lower thread 60.

[0046] like Figure 5 As shown, after the upper thread 50 is pulled down by the thread take-up lever 6, the cloth 100 is moved by the feeding device, thereby forming a stitch on the cloth 100. Figures 2 to 5 The described operation forms a predetermined stitch on the cloth 100 .

[0047] [Thread trimmer]

[0048] Figure 6 This is a perspective view of the thread cutting device 20 according to the embodiment as viewed from above. Figure 7 This is a diagram of the thread cutting device 20 according to the embodiment as viewed from the right. Figure 8 This is a diagram showing the thread cutting device 20 according to the embodiment as viewed from below.

[0049] The thread trimmer 20 cuts the upper thread 50 and the lower thread 60 when the sewing machine needle 4 is positioned above the needle plate 7. The thread trimmer 20 is positioned below the needle plate 7. The thread trimmer 20 includes a fixed knife 21 fixed to the lower surface of the needle plate 7; a movable knife 22 pivotable about a pivot 7B provided on the lower surface of the needle plate 7; and an elastic member 23 that generates an elastic force that presses the movable knife 22 toward the fixed knife 21. The movable knife 22 is positioned below the fixed knife 21. When the upper thread 50 and the lower thread 60 are hooked on the movable knife 22, the movable knife 22 approaches the fixed knife 21, whereupon the blade 22F of the movable knife 22 and the blade 21B of the fixed knife 21 cut the upper thread 50 and the lower thread 60.

[0050] The fixed cutter 21 includes a main body 21A and a blade 21B. The blade 21B is provided at the rear end of the main body 21A. The left end of the main body 21A is fixed to the lower surface of the needle plate 7 by two screws 24.

[0051] The elastic member 23 is a leaf spring located below the needle plate 7. The elastic member 23 is positioned below the stationary knife 21. The left end of the elastic member 23 is secured to the lower surface of the needle plate 7 by two screws 24. The screws 24 secure the elastic member 23 and the stationary knife 21 to the needle plate 7, respectively. The elastic member 23 biases the movable knife 22 toward the needle plate 7.

[0052] Figure 9 This is a perspective view of the movable knife 22 according to the embodiment as viewed from above. The movable knife 22 includes a main body portion 22A, a bending portion 22B, and a treatment portion 22C.

[0053] The main body 22A is rotatably supported by the pivot 7B. The rotation axis of the pivot 7B extends in the vertical direction. The pivot 7B protrudes downward from the lower surface of the needle plate 7. The main body 22A has a rotation hole 22D for inserting the pivot 7B. The movable cutter 22 can rotate about the pivot 7B.

[0054] The main body 22A is connected to an operating lever 26 via a rotation pin 25. The rotation pin 25 is inserted into a pin hole 22L provided in the main body 22A. The operating lever 26 is moved in the front-to-back direction by the operation of an actuator (not shown). The front-to-back movement of the operating lever 26 causes the movable cutter 22 to rotate about the pivot 7B.

[0055] The curved portion 22B connects the main body portion 22A and the treatment portion 22C. The treatment portion 22C is connected to the main body portion 22A via the curved portion 22B.

[0056] The treatment portion 22C includes a tip portion 22E; a blade portion 22F adjacent to the tip portion 22E; a first guide portion 22G connected to the tip portion 22E; a second guide portion 22H connected to the tip portion 22E; a first recess 22J connected to the first guide portion 22G; and a second recess 22K connected to the second guide portion 22H. With the radial direction radiating from the pivot 7B as the center, the second guide portion 22K is positioned radially outward of the first guide portion 22G.

[0057] Figure 10 1 is a diagram showing the operation of the movable cutter 22 according to the embodiment. Figure 10 As shown, the movable knife 22 is capable of rotating between a standby position Pa and an advance / exit position Pb. The movable knife 22 rotates between the standby position Pa and the advance / exit position Pb below the fixed knife 21. When the movable knife 22 is in the standby position Pa, the curved portion 22B and a portion of the treatment portion 22C of the movable knife 22 are positioned between the elastic member 23 and the fixed knife 21. When the movable knife 22 is in the standby position Pa, the elastic member 23 contacts the lower surface of the movable knife 22. When the movable knife 22 is in the standby position Pa, the elastic member 23 generates an elastic force that presses the movable knife 22 toward the fixed knife 21. When the movable knife 22 is in the advance / exit position Pb, the movable knife 22 is pulled out from between the fixed knife 21 and the elastic member 23. When the movable knife 22 is in the advance / exit position Pb, the elastic member 23 faces the lower surface of the fixed knife 21. When the movable knife 22 is at the advancing position Pb, the elastic member 23 may contact the lower surface of the stationary knife 21. When the movable knife 22 is at the advancing position Pb, the elastic member 23 may generate an elastic force to press the stationary knife 21 toward the needle plate 7.

[0058] As described above, the cloth 100 moves in the left-right direction. The fixed cutter 21 and the movable cutter 22 arranged at the standby position Pa are each arranged in front of the needle hole 7A.

[0059] By moving the operating lever 26 in the front-to-back direction, the movable knife 22 rotates about the pivot 7B. By moving the operating lever 26 rearward, the movable knife 22 is positioned in the standby position Pa. By moving the operating lever 26 forward, the movable knife 22 is positioned in the forward-removal position Pb. During the rotation of the movable knife 22, the tip 22E passes directly below the needle hole 7A.

[0060] [action]

[0061] Next, the operation of the thread cutting device 20 will be described. Figure 11 This is a perspective view for explaining the operation of the movable knife 22 according to the embodiment. Figure 12 、 Figure 13 as well as Figure 14 Each of them is a diagram showing the thread cutting device 20 according to the embodiment as viewed from below.

[0062] like Figure 11 As shown, the thread cutting device 20 cuts the upper thread 50 and the lower thread 60 when the sewing machine needle 4 is raised and separated from the cloth 100. Figure 3 As described above, when the sewing machine needle 4 rises and separates from the cloth 100, the upper thread loop 51 is formed below the cloth 100. Figure 11 The upper thread loop 51 is substantially triangular in shape. The upper thread loop 51 includes a needle side portion 51A between the sewing machine needle 4 and the semi-rotating kettle 10 and a stitch side portion 51B between the semi-rotating kettle 10 and the stitch 101. Figure 12 As shown, in the radial direction of the pivot shaft 7B, the needle side portion 51A is arranged radially outward of the stitch side portion 51B and the bobbin thread 60 .

[0063] When cutting the upper thread 50 and the lower thread 60, the movable cutter 22 rotates from the standby position Pa toward the in-and-out position Pb. Figure 13 As shown, the movable cutter 22 rotates toward the in-and-out position Pb, and the tip 22E of the processing portion 22C enters the inner side of the upper thread loop 51. The processing portion 22C enters the inner side of the upper thread loop 51 and divides the upper thread loop 51 into a needle side portion 51A and a stitch side portion 51B. Figure 13 As shown, the processing portion 22C enters the upper thread loop 51 so that the needle side portion 51A is arranged radially outward of the pivot shaft 7B relative to the stitch side portion 51B and the lower thread 60 .

[0064] After the tip 22E enters the upper thread loop 51, the movable knife 22 further rotates toward the entry / exit position Pb, causing the stitch-side portion 51B and the bobbin thread 60 to contact the first guide portion 22G, and the needle-side portion 51A to contact the second guide portion 22H. With the stitch-side portion 51B and the bobbin thread 60 in contact with the first guide portion 22G, and the needle-side portion 51A in contact with the second guide portion 22H, the movable knife 22 rotates toward the entry / exit position Pb.

[0065] like Figure 14 As shown, when the movable knife 22 rotates toward the entry / exit position Pb, the stitch portion 51B and the bobbin thread 60 are positioned near the first recess 22J, while the needle portion 51A is positioned in the second recess 22K. In the embodiment, as the movable knife 22 rotates toward the entry / exit position Pb, the stitch portion 51B and the bobbin thread 60 are guided by the first guide 22G to be positioned near the first recess 22J, while the needle portion 51A is guided by the second guide 22H to be positioned in the second recess 22K. The second recess 22K is spaced a certain distance from the first recess 22J, ensuring that the needle portion 51A of the upper thread 50, which will be cut at the stitch portion 51B, remains a certain distance from the threading hole 4A of the sewing machine needle 4.

[0066] When the stitch side portion 51B and the lower line 60 are arranged near the first recess 22J, the movable cutter 22 is rotated from the entry and exit position Pb toward the standby position Pa, and the stitch side portion 51B and the lower line 60 are arranged in the first recess 22J, and the stitch side portion 51B and the lower line 60 are cut by the blade 21B of the fixed cutter 21 and the blade 22F of the movable cutter 22.

[0067] [Effect]

[0068] As described above, according to the embodiment, the upper thread loop 51 is divided into the needle-side portion 51A and the stitch-side portion 51B by the processing unit 22C. The stitch-side portion 51B is the portion of the upper thread loop 51 that should be cut. The needle-side portion 51A is the portion of the upper thread loop 51 that should not be cut. The processing unit 22C separates the upper thread loop 51 into the needle-side portion 51A and the stitch-side portion 51B, so that the needle-side portion 51A moves radially outward relative to the stitch-side portion 51B. The fixed cutter 21 and the movable cutter 22 are each positioned approximately to the left of the needle hole 7A.

[0069] Figure 15 1 is a diagram illustrating the effect of the thread cutting device 20 according to the embodiment. Figure 15As shown, in the case where the sewing machine is a double-needle sewing machine, a pair of needle plates 7 (7L, 7R) are provided in the sewing machine. A thread cutting device 20 is arranged below each of the pair of needle plates 7 (7L, 7R). Two thread cutting devices 20 are provided in a manner corresponding to the two sewing machine needles 4. The thread cutting device 20 includes a thread cutting device 20L arranged below the needle plate 7L and a thread cutting device 20R arranged below the needle plate 7R. The thread cutting device 20L has a fixed cutter 21L, a movable cutter 22L and an elastic component 23L. The thread cutting device 20R has a fixed cutter 21R, a movable cutter 22R and an elastic component 23R. As Figure 15 As shown, when the pair of needle plates 7 (7L, 7R) are aligned in the front-to-back direction, with the distance between the needle holes 7A in needle plates 7L and 7R shortened, the pair of movable knives 22 (22L, 22R) can rotate without interfering with each other or surrounding objects. On needle plate 7L, a fixed knife 21L is positioned to the right of needle hole 7A in needle plate 7L, and a movable knife 22L is positioned in a standby position Pa. On needle plate 7R, a fixed knife 21R is positioned to the left of needle hole 7A in needle plate 7R, and a movable knife 22R is positioned in a standby position Pa. Since the thread trimmer 20L is positioned to the right of the needle hole 7A and the thread trimmer 20R is positioned to the left of the needle hole 7A, interference between the thread trimmers 20L and 20R can be minimized, and the needle hole 7A of the needle plate 7L and the needle hole 7A of the needle plate 7R can be brought closer together. In a double-needle sewing machine, the distance between the pair of needle holes 7A can be shortened. In a double-needle sewing machine using a semi-rotary kettle, the distance between the two sewing needles 4 can be shortened.

Claims

1. A sewing machine comprising: A needle bar that holds a sewing machine needle with a needle thread hanging thereon and reciprocates in the vertical direction; a needle plate, which is arranged below the needle bar and has a needle hole for inserting the sewing machine needle; a kettle, which is arranged below the needle plate and supplies the lower wire; as well as a thread cutting device for cutting the upper thread and the lower thread when the sewing machine needle is arranged above the needle plate; The thread cutting device comprises: a fixed cutter fixed to the lower surface of the needle plate; and The movable cutter can rotate between a standby position and an in-and-out position around a pivot provided on the lower surface of the needle plate. The movable cutter has a processing portion, By rotating toward the in-and-out position, the processing portion enters an upper thread loop formed below the needle hole, dividing the upper thread loop into a needle side portion and a stitch side portion. The processing portion enters the upper thread loop such that the needle side portion is arranged radially outward of the pivot axis relative to the stitch side portion and the lower thread.

2. The sewing machine according to claim 1, characterized in that The processing unit has: a tip portion that enters the upper wire loop; a first guide portion connected to the tip portion; a second guide portion connected to the tip portion and arranged radially outward of the first guide portion; a first recessed portion connected to the first guide portion; as well as a second recessed portion connected to the second guide portion, The stitch side portion and the lower thread are guided by the first guide portion to be arranged in the first recessed portion. The needle-side portion is guided by the second guide portion to be arranged in the second recess.

3. The sewing machine according to claim 2, characterized in that When the movable knife rotates toward the standby position while the stitch side portion and the bobbin thread are arranged in the first recess, the stitch side portion and the bobbin thread are cut by the blades of the fixed knife and the movable knife.

4. The sewing machine according to claim 1, wherein The fixed cutter and the movable cutter disposed at the standby position are respectively disposed to the left of the needle hole.

5. The sewing machine according to claim 1, characterized in that The thread cutting device has an elastic component, The elastic member is provided below the needle plate and generates an elastic force for pressing the movable knife toward the fixed knife.

6. The sewing machine according to claim 5, characterized in that The movable cutter rotates between the standby position and the in-and-out position at a position lower than the fixed cutter. The elastic member presses the movable knife toward the fixed knife when the movable knife is located at the standby position.

7. The sewing machine according to claim 1, characterized in that The movable cutter has: a main body supported by the pivot; and A curved portion connects the main body portion and the processing portion.

8. The sewing machine according to claim 1, wherein The kettle is a semi-rotating kettle, The semi-rotating kettles are provided with two opposed to each other. The sewing machine needles are provided with two, There are two thread cutting devices.

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