JP2014188354A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine capable of adequately cutting threads.SOLUTION: A sewing machine includes a bed part, a post part, an arm part, a thread cutter 16 which cuts a thread, and a link mechanism 20 which transmits a rotating power of an upper shaft to the thread cutter. The link mechanism 20 includes a rod-like second link 22, a rocking mechanism 40 which rocks along with movement of the second link 22, and a rod-like blade side link 23 which moves in a drawing direction along with the rocking of the rocking mechanism 40. The rocking mechanism 40 includes a rod-like shaft part 412, a body member 41 equipped with a fixing lever part 411 which connects with the blade side link 23 by extending from one end of the shaft part 412 in a direction crossing an axial direction of the shaft part 412, and a movable lever member 42 which connects with the other end of the shaft part 412 of the body member 41 in a rotatable manner and links with the second link 22. The rocking mechanism 40 supports a space of the shaft part 412 between the fixing lever part 411 and the movable lever member 42 to the bed part in a rocking manner.

Description

  The present invention relates to a sewing machine having a thread trimming mechanism.

  There is a sewing machine provided with a thread trimming mechanism that cuts a thread by using the rotating force of the upper shaft. Patent Document 1 discloses a sewing machine provided with a thread trimming mechanism including a movable blade and a fixed blade provided on the lower side of a needle plate and a link mechanism. In the sewing machine of Patent Document 1, the link mechanism transmits the rotating force of the upper shaft to the movable blade. The link mechanism includes a first link, a second link, a third link, and a swing mechanism. The first link extends in the vertical direction within the pedestal. The first link moves in the stretching direction as the upper shaft rotates. The second link extends in the front-rear direction within the bed portion. The second link moves in the extending direction as the first link moves. The swing mechanism is connected to the second link and the third link, and swings as the second link moves. The third link moves in the front-rear direction as the swing mechanism swings. The third link is connected to the movable blade. The third link drives the movable blade, and the movable blade cooperates with the fixed blade to cut the yarn.

  The swing mechanism includes a support shaft, a swing lever, a first swing arm, and a second swing arm. The support shaft extends downward from the lower end of the swing lever. The support shaft supports the swing lever so as to be swingable. The first swing arm extends in the horizontal direction from the upper end of the swing lever. A third link is connected to the tip of the first swing arm. The second swing arm extends in the extending direction from the lower end of the swing lever. A second link is connected to the tip of the second swing arm. The swing mechanism swings about the support shaft as the swing center when the second link moves in the horizontal direction. The swing mechanism adjusts the drive timing of the movable blade by changing the swing range with respect to the movement of the second link.

JP 2008-229082 A

  In the swing mechanism, the second link and the third link are connected to the upper side of the support shaft. When the sewing machine cuts the yarn, a force acts on the second link and the third link. Therefore, since the force acts only on the upper side of the support shaft, the swing shaft is easily deformed when an extremely large force is applied to the second link and the third link. The sewing machine has a problem that when the support shaft is deformed, the swing mechanism cannot swing properly with respect to the movement of the second link, and the driving state of the third link becomes unstable, so that the yarn cannot be cut appropriately. .

  The objective of this invention is providing the sewing machine which can cut | disconnect a thread | yarn appropriately.

  The sewing machine according to the first aspect of the present invention includes a bed portion, a leg column portion that extends upward from one end portion of the bed portion, and an upper shaft that extends from the upper end of the leg column portion to face the bed portion. Is disposed on the other end of the bed and on the lower side of the needle plate, and transmits the thread cutting blade for cutting the thread and the rotating force of the upper shaft to the thread cutting blade. In the sewing machine having a link mechanism, the link mechanism is connected to the upper shaft side link that moves in the extending direction along with the rotation of the upper shaft, and the upper shaft side link to move the upper shaft side link. A swing mechanism that swings along with the blade, and a blade-side link that has one end connected to the swing mechanism and the other end extending to the thread cutting blade, and moves in the extending direction as the swing mechanism swings. The swinging mechanism includes a shaft portion extending in a direction intersecting the extending direction of the upper shaft side link, And a main body member provided with a fixing lever portion extending from one end portion of the shaft portion in a direction intersecting the axial direction of the shaft portion and connected to the blade side link, and the other end portion of the shaft portion of the main body member And a movable lever member that extends in a direction intersecting the axial direction and is connected to the upper shaft side link, wherein the swing mechanism includes the fixed lever portion and the fixed lever portion of the shaft portion. The movable lever member is supported by the bed portion so as to be swingable.

  The sewing machine which concerns on a 1st aspect supports a rocking | fluctuation mechanism so that rocking | fluctuation is possible by the axial part between a fixed lever part and a movable lever member. When the sewing machine cuts the yarn, a force acts on both ends of the swing mechanism provided with the fixed lever portion and the movable lever member. Since the forces acting on the swing mechanism are balanced, the swing of the swing mechanism is stable. Therefore, since the thread cutting blade is appropriately driven as the swinging mechanism swings, the sewing machine can appropriately cut the thread.

  The movable lever member of the sewing machine according to the first aspect is connected to the other end portion of the shaft portion and the upper shaft side link, and extends to extend in a direction intersecting the axial direction of the shaft portion, A frame portion connected to an end portion of the extension portion on the shaft portion side and provided with a hole that rotatably supports the extension portion on the shaft portion, and the frame portion cannot be rotated with respect to the shaft portion You may provide the fixing | fixed part to fix. The movable lever member of the sewing machine can be adjusted to a plurality of states in which the extending direction of the extending portion differs with respect to the main body member by rotating the frame portion with respect to the shaft portion. The fixed portion can fix the movable lever member to the main body member in a plurality of states in which the extending portions extend differently from the main body member. The swinging mechanism of the swinging mechanism changes in accordance with the extending direction of the extending portion, and the driving range of the thread cutting blade changes. Therefore, the sewing machine can easily adjust the drive range of the thread cutting blade by adjusting the extending direction of the extending portion with respect to the main body member so that the timing at which the thread cutting blade cuts the thread is appropriate.

  The frame part of the sewing machine according to the first aspect includes a cylindrical first frame part having the hole on an inner peripheral surface, a second frame part provided on an outer periphery of the cylinder of the first frame part, and the first A slit groove provided over the frame portion and the second frame portion and extending along the axis of the hole, and the second frame portion extends in a direction perpendicular to the direction in which the slit groove extends to extend the slit. A screw hole that penetrates the groove, and the fixing portion includes a screw that is inserted into the screw hole and narrows the width of the slit groove by passing through the slit groove, and the screw is inserted into the screw hole. By narrowing the width of the slit groove, the inner diameter of the hole of the first frame portion may be narrowed so as to be in close contact with the outer peripheral surface of the shaft portion and fixed unrotatable. The sewing machine can adjust the diameter of the hole by adjusting the degree to which the screw is tightened. The sewing machine can adjust the extending direction of the extending portion of the movable lever member with respect to the main body member to a plurality of states only by loosening the screw. The sewing machine can fix the movable lever member to the main body member simply by tightening the screw. Therefore, the operator can easily change the extending direction of the extending portion of the movable lever member with respect to the main body member.

  The swing mechanism of the sewing machine according to the first aspect may include a fixed member that fixes the movable lever member to the opposite side of the fixed lever portion with respect to the shaft portion of the main body member. The fixed member suppresses the movement of the movable lever member in the axial direction in a state where the movable lever member is not fixed to the main body member. The movable lever member prevents the position of the shaft portion from shifting in the vertical direction even if the fixing to the main body member is loosened when adjusting the extending direction of the extending portion. Therefore, the operator can reliably connect the movable lever member to the predetermined position of the main body member when adjusting the extending direction of the extending portion.

  The sewing machine according to the second aspect of the present invention includes a bed portion, a leg column portion that extends upward from one end portion of the bed portion, and an upper shaft that extends from the upper end of the leg column portion to face the bed portion. Is disposed on the other end of the bed and on the lower side of the needle plate, and transmits the thread cutting blade for cutting the thread and the rotating force of the upper shaft to the thread cutting blade. In the sewing machine having a link mechanism, the link mechanism is connected to the upper shaft side link that moves in the extending direction along with the rotation of the upper shaft, and the upper shaft side link to move the upper shaft side link. A swing mechanism that swings along with the blade, and a blade-side link that has one end connected to the swing mechanism and the other end extending to the thread cutting blade, and moves in the extending direction as the swing mechanism swings. The swinging mechanism includes a shaft portion extending in a direction intersecting the extending direction of the upper shaft side link, And a main body member having a fixing lever portion extending from one end portion of the shaft portion in a direction intersecting the axial direction of the shaft portion and connected to the upper shaft side link, and the other end of the shaft portion of the main body member A movable lever member connected to the blade side link and extending in a direction intersecting the axial direction, and the swing mechanism includes the fixed lever portion and the fixed lever portion of the shaft portion. The movable lever member is fixed to the bed portion so as to be swingable.

  The sewing machine which concerns on a 2nd aspect supports a rocking | fluctuation mechanism so that rocking | fluctuation is possible by the axial part between a fixed lever part and a movable lever member. When the sewing machine cuts the yarn, a force acts on both ends of the swing mechanism provided with the fixed lever portion and the movable lever member. Since the forces acting on the swing mechanism are balanced, the swing of the swing mechanism is stable. Therefore, since the thread cutting blade is appropriately driven as the swinging mechanism swings, the sewing machine can appropriately cut the thread.

The perspective view of the sewing machine 1. FIG. The right view of the sewing machine 1. FIG. FIG. The bottom view of the sewing machine 1. FIG. The perspective view of the link mechanism 20 and the transmission mechanism 70. FIG. The top view of the transmission mechanism 70. FIG. The top view of the transmission mechanism 70. FIG. The expansion perspective view of the connection part 24. FIG. FIG. 3 is an enlarged perspective view of a swing mechanism 40. The perspective view of the main body member 41. FIG. The perspective view of the movable lever member 42. FIG. The perspective view of the movable lever member 42. FIG. The perspective view of the thread cutting blade 16 and the rocking | fluctuation mechanism 40. FIG. The top view of the thread trimming blade 16 in a 1st state. The top view of the thread trimming blade 16 in a 2nd state. 16 is a plan view of the thread trimmer in the third state. The right view of the connection part 24. FIG. The perspective view of the rocking | swiveling mechanism 40 and the thread trimming blade 16. FIG. The right view of the connection part 24. FIG. The perspective view of the rocking | swiveling mechanism 40 and the thread trimming blade 16. FIG. The top view at the time of changing the drive range of the movable blade 18. FIG. The perspective view of the rocking | swiveling mechanism 40 and the thread cutting blade 16 in a modification.

  Hereinafter, a sewing machine 1 according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the diagonally lower left, diagonally upper right, diagonally upper left, and diagonally lower right in FIG. 1 are defined as the front, rear, left, and right sides of the sewing machine 1, respectively. The X-axis direction is the left-right direction of the sewing machine 1. The Y-axis direction is the front-rear direction of the sewing machine 1.

  The structure of the sewing machine 1 will be described with reference to FIGS. The sewing machine 1 includes a bed 2, a pedestal 3, and an arm 4. The bed portion 2 extends in the front-rear direction. The bed portion 2 includes a first bed portion 8 and a second bed portion 9. The first bed portion 8 is located behind the sewing machine 1, and the second bed portion 9 is located in front of the first bed portion 8. The shape of the first bed portion 8 is a substantially rectangular parallelepiped box shape. The first bed portion 8 includes a lower shaft 7, a gear mechanism 10 and the like inside. The gear mechanism 10 is disposed in the vicinity of the rear end of the lower shaft 7. As shown in FIG. 8, the gear mechanism 10 includes a gear 101, a gear shaft portion 102, and a connecting portion 103. The gear 101 has a substantially fan shape centered on the gear shaft portion 102 and meshes with a gear 701 provided at the rear end of the lower shaft 7. The gear 101 can swing around the gear shaft portion 102. The connecting portion 103 is integrally formed with the gear 101 and can swing around the gear shaft portion 102. The connecting portion 103 is connected to the eccentric shaft 62 of the upper shaft 6 via a crank rod (not shown). The gear mechanism 10 transmits the rotational driving force of an upper shaft motor (not shown) transmitted through the eccentric shaft 62 of the upper shaft 6 and the crank rod to the lower shaft 7. A lubricant is applied to the gear mechanism 10 via a felt (not shown). The lower shaft 7 drives the shuttle mechanism 11.

  The second bed portion 9 includes a needle plate support portion 91 and a storage portion 92. The accommodating portion 92 is located in front of the first bed portion 8. The shape of the accommodating part 92 is a substantially rectangular parallelepiped box shape. The length of the storage portion 92 in the left-right direction is longer than the length of the first bed portion 8 in the left-right direction. The vertical length of the accommodating portion 92 is substantially the same as the vertical length of the first bed portion 8. The accommodating portion 92 includes the lower shaft 7, a cloth feeding mechanism (not shown), and the like. The lower shaft 7 extends in a straight line in the front-rear direction at the substantially left and right center of the housing portion 92. A connecting portion between the front side surface of the first bed portion 8 and the rear side surface of the accommodating portion 92 forms a wall portion 96. The wall portion 96 separates the first bed portion 8 and the accommodating portion 92. A shaft hole 97 is provided in the wall portion 96. The shaft hole 97 passes through the wall portion 96. The diameter of the shaft hole 97 is large enough to allow the lower shaft 7 to be inserted. The lower shaft 7 passes through the shaft hole 97 and extends between the first bed portion 8 and the second bed portion 9 (the needle plate support portion 91 and the accommodating portion 92).

  A link placement portion 921 is provided on the lower surface of the housing portion 92. The link placement portion 921 is formed in a groove shape with the lower surface of the housing portion 92 recessed upward. The link placement portion 921 extends in a straight line in the front-rear direction at the substantially left and right center of the housing portion 92. The link placement portion 921 extends from the front end to the rear end of the lower surface of the storage portion 92. A second link 22 to be described later is arranged in the link arrangement unit 921. Four base feet 922 are provided on the lower surface of the housing portion 92. Each of the four base legs 922 has a substantially cylindrical shape. The four base feet 922 protrude downward from the four corners of the lower surface of the housing portion 92. The base leg 922 is a base that supports the sewing machine 1 with its lower surface in contact with a table (not shown).

  The throat plate support 91 protrudes forward from the front side of the accommodating portion 92 and from the substantially right and left center. The shape of the throat plate support 91 is a box shape in which the lower side of the substantially rectangular parallelepiped is curved. The length of the needle plate support 91 in the vertical direction is substantially half of the length of the storage portion 92 in the vertical direction. The upper surface of the needle plate support portion 91 is positioned slightly above the upper surface of the accommodation portion 92. The throat plate support 91 and the accommodating portion 92 communicate with each other without being separated by a wall. The throat plate support 91 includes the lower shaft 7, the shuttle mechanism 11, the thread cutting blade 16, and the like. The lower shaft 7 extends in the throat plate support 91 in the front-rear direction. The shuttle mechanism 11 is connected to the front end of the lower shaft 7. The work table 5 is provided on the upper surface of the needle plate support 91. The workbench 5 includes a needle plate 12 substantially at the center. The needle plate 12 is provided with a needle hole (not shown) at substantially the center.

  The pedestal part 3 extends upward from the upper part of the first bed part 8. The arm portion 4 extends forward from the upper end of the pillar portion 3 so as to face the bed portion 2. The upper shaft 6 extends in the front-rear direction inside the arm portion 4 and the leg column portion 3. The rear end of the upper shaft 6 is connected to an upper shaft motor (not shown), and a transmission mechanism 70 is provided on the front side of the upper shaft motor. The eccentric shaft 62 described above is provided in front of the transmission mechanism 70 in the upper shaft 6. The arm part 4 includes a tip part 111 at the front end part. The upper surface of the needle plate 12 faces the lower end of the tip 111. The tip 111 includes a needle bar drive mechanism 61, a needle bar, a presser bar (not shown), and the like. A sewing needle (not shown) is connected to the tip of the needle bar. A presser foot (not shown) is connected to the tip of the presser bar. The needle bar drive mechanism 61 is connected to the front end of the upper shaft 6. The upper shaft 6 drives the needle bar drive mechanism 61 to move the needle bar up and down.

  The bed part 2 is provided with a cloth presser mechanism 93 on the upper side. A cloth feed mechanism (not shown) provided inside the accommodating portion 92 is connected to the cloth presser mechanism 93. The presser foot mechanism 93 includes a presser frame 94 and a sandwiching frame 95. The presser frame 94 is a frame member having an opening having a substantially rectangular shape in plan view. The presser frame 94 can be moved up and down by driving a presser up and down movement mechanism (not shown). The sandwiching frame 95 is located below the presser frame 94 and has an opening having substantially the same shape as the opening of the presser frame 94. The cloth presser mechanism 93 holds a work cloth (not shown) between the presser frame 94 and the sandwiching frame 95 and holds it on the work table 5. The cloth feed mechanism supports the cloth presser mechanism 93 so as to be movable in the X-axis direction and the Y-axis direction. The sewing needle reciprocates up and down as the upper shaft 6 rotates. The upper shaft 6 is driven by an upper shaft motor. As described above, the shuttle mechanism 11 is driven as the lower shaft 7 is driven. The lower shaft 7 is driven by the driving force of the upper shaft motor. The control device of the sewing machine 1 controls the cloth feeding mechanism based on the sewing data. The cloth feed mechanism drives the cloth presser mechanism 93 in the X-axis direction and the Y-axis direction. The work cloth moves on the work table 5 in the X-axis direction and the Y-axis direction. The sewing machine 1 drives the shuttle mechanism 11 while moving the sewing needle up and down to move the work cloth. Therefore, the sewing machine 1 can form a seam on the work cloth.

  The structure of the thread cutting blade 16, the link mechanism 20, and the transmission mechanism 70 will be described with reference to FIGS. The transmission mechanism 70 transmits the rotational force of the upper shaft 6 to the link mechanism 20. The link mechanism 20 transmits the rotational force of the upper shaft 6 to the movable blade 18 of the thread cutting blade 16. The thread cutting blade 16 cuts the thread.

  As shown in FIG. 5, the transmission mechanism 70 is disposed in the pedestal 3 at the rear of the arm 4. The transmission mechanism 70 includes a cam plate 71, a drive lever 72, a solenoid 73, and a rotation plate 75. The cam plate 71 is connected behind the eccentric shaft 62 and in front of the upper shaft motor. The shape of the cam plate 71 is a circular plate shape, and the upper shaft 6 passes through the axis of the cam plate 71. The cam plate 71 rotates as the upper shaft 6 rotates. A cam groove 71 </ b> A is provided on the front side surface of the cam plate 71. The cam groove 71A is a groove formed on the entire circumference so as to be recessed backward from the front side surface of the cam plate 71.

  The drive lever 72 is provided in front of the cam plate 71 and above the upper shaft 6. The shape of the drive lever 72 is a plate shape long in the left-right direction, and the upper end of the first link 21 is connected to the right end. As shown in FIG. 6, the direction in which the first link 21 extends slightly inclines backward from the right end of the drive lever 72 with respect to the downward vertical direction. As shown in FIGS. 6 and 7, the drive lever 72 is provided with a projecting portion 72 </ b> A projecting rearward on the left side from the right end. The protruding portion 72A has a cam groove 71A located behind and can engage with the cam groove 71A. The drive lever 72 includes a restricting portion 72B that protrudes forward at the upper right end of the protruding portion 72A. The restricting portion 72B comes into contact with a restricting piece (not shown) provided on the arm portion 4 from below, and restricts the upward swing of the drive lever 72. The position of the drive lever 72 regulated by the regulating part 72B and the regulating piece is a position where the projecting part 72A is reliably engaged with the cam groove 71A. The drive lever 72 has a through hole (not shown) extending in the front-rear direction on the right side of the left end. A rod-shaped shaft 74 extending in the front-rear direction is inserted through the through hole. The drive lever 72 can rotate about the shaft 74 and can move in the front-rear direction along the shaft 74. A spring (not shown) is wound around the shaft 74 behind the drive lever 72. The spring biases the drive lever 72 forward.

  The solenoid 73 is provided in front of the left end of the drive lever 72. As shown in FIGS. 6 and 7, the solenoid 73 includes a main body portion 731 and a plunger 732. The main body 731 has a substantially cylindrical shape. The plunger 732 extends in the front-rear direction. The plunger 732 is inserted into a hole provided at the axial center position of the main body portion 731. A cylindrical portion 733 is provided at the rear end of the plunger 732. The cylindrical portion 733 extends upward from the plunger 732. The solenoid 73 can move the plunger 732 in the front-rear direction by switching between energization and non-energization.

  The rotating plate 75 is provided behind the cylindrical portion 733 and in front of the left end of the drive lever 72. The shape of the rotating plate 75 is a plate shape. As shown in FIG. 6, a hole 751 penetrating in the vertical direction is provided on the left end side of the rotation plate 75. A step screw 752 extending in the vertical direction is inserted into the hole 751. The step screw 752 is fastened to the arm portion 4. The rotating plate 75 includes projecting portions 753 and 754. The protruding portion 753 protrudes rearward at the right end portion of the rotating plate 75. The protruding portion 754 protrudes forward at the front end portion of the rotating plate 75. The rotating plate 75 can be rotated with a step screw 752 as a fulcrum, and the protrusion 753 on the right end side of the rotating plate 75 can swing. The protruding portion 754 contacts the cylindrical portion 733, and the protruding portion 753 contacts the front side surface of the left end of the drive lever 72.

  As shown in FIG. 6, when the solenoid 73 is not energized, the plunger 732 is positioned forward. When the plunger 732 is positioned forward, the left end of the drive lever 72 contacts the protrusion 753 of the rotating plate 75 and pushes the protrusion 753 forward by the biasing force of the spring provided on the shaft 74. The rotating plate 75 rotates until the protruding portion 754 comes into contact with the cylindrical portion 733. The drive lever 72 moves forward along the shaft 74. The protrusion 72A of the drive lever 72 is separated from the cam groove 71A. Therefore, the drive lever 72 does not swing even when the upper shaft 6 rotates. In this state, the right end of the drive lever 72 is disposed above the swing range.

  As shown in FIG. 7, when the solenoid 73 is energized, the plunger 732 moves backward. When the plunger 732 moves backward, the cylindrical portion 733 pushes the protruding portion 754 of the rotating plate 75 backward. The rotating plate 75 rotates, and the projecting portion 753 contacts the left end of the driving lever 72 to push the driving lever 72 backward. The drive lever 72 moves rearward along the shaft 74. The protrusion 72A engages with the cam groove 71A. Therefore, when the upper shaft 6 rotates, the protrusion 72A moves along the cam groove 71A. The protrusion 72A moves in the vertical direction, and the right end of the drive lever 72 swings about the shaft 74 as a fulcrum.

  As shown in FIGS. 5 to 8, the link mechanism 20 includes a first link 21, a connection portion 24, a second link 22, a swing mechanism 40, and a blade side link 23 (see FIG. 9). The first link 21, the connection portion 24, and the second link 22 are interposed between the swing mechanism 40 and the transmission mechanism 70. The blade side link 23 is interposed between the swing mechanism 40 and the thread cutting blade 16. The first link 21 is a rod-shaped member. The first link 21 extends in the vertical direction over the pedestal 3 and the first bed 8 (see FIG. 1) of the bed 2. The first link 21 passes to the right of the upper shaft 6. The upper end of the first link 21 is connected to the right end of the drive lever 72 of the transmission mechanism 70. The first link 21 is movable in the extending direction (vertical direction) with the swing of the right end of the drive lever 72.

  As shown in FIG. 8, the connecting portion 24 is disposed in the first bed portion 8 and below the gear mechanism 10. The connection unit 24 includes a rotation unit 241 and a shaft unit 242. The rotating part 241 includes a cylindrical part 245, a first arm part 243, and a second arm part 244. The cylindrical portion 245 has a cylindrical shape extending in the left-right direction. The first arm portion 243 has a plate shape extending rearward from the right side of the cylindrical portion 245. The second arm portion 244 has a plate shape extending downward from the left side of the cylindrical portion 245. The lower end of the first link 21 is connected to the rear end of the first arm portion 243. The first link 21 extends upward from the rear end of the first arm portion 243 through the right side of the gear mechanism 10. The rear end of the second link 22 is connected to the lower end of the second arm portion 244. The second arm portion 244 includes a protruding portion 247 (see FIG. 17) that protrudes rearward from a substantially central portion in the vertical direction. The protrusion 247 has a hole 246 (see FIG. 17) at the rear end. The hole 246 can be attached to one end of a spring (not shown). The spring fixes the other end to the first bed portion 8. The shaft portion 242 has a rod shape with a circular cross section, and penetrates the cylindrical portion 245 in the left-right direction. The shaft portion 242 is a shaft that rotatably supports the rotating portion 241. The rotating part 241 can rotate with the cylindrical part 245 as a fulcrum as the first link 21 moves in the extending direction. The rotating part 241 is always urged counterclockwise as viewed from the right side by a spring. Due to the urging, the first link 21 moves upward, and the drive lever 72 swings upward until the restricting portion 72B contacts the restricting piece of the arm portion 4.

  As shown in FIG. 5, the second link 22 extends in the front-rear direction. The shape of the second link 22 is a rod shape extending in a straight line. The rear end of the second link 22 is connected to the lower end of the second arm portion 244 (see FIG. 8) of the rotating portion 241. The second link 22 extends below the lower shaft 7. As shown in FIG. 4, the second link 22 extends forward from the first bed portion 8. The second link 22 passes through the link placement portion 921 on the lower surface of the housing portion 92. Therefore, the second link 22 does not protrude downward from the lower surface of the housing portion 92. The front end of the second link 22 protrudes forward from the front end of the link placement portion 921.

  As shown in FIG. 4, the swing mechanism 40 is provided at a connection portion between the needle plate support portion 91 and the accommodating portion 92 and below the connection portion. As shown in FIG. 9, the swing mechanism 40 includes a main body member 41, a movable lever member 42, and a fixed member 44. The main body member 41 includes a fixed lever portion 411 and a shaft portion 412. The shaft portion 412 has a rod shape with a circular cross section. The shaft portion 412 extends in the vertical direction. The fixed lever portion 411 is provided at the upper end of the shaft portion 412. The fixed lever portion 411 extends from the upper end of the shaft portion 412 to the right and in a direction orthogonal to the extending direction (vertical direction) of the shaft portion 412. As shown in FIG. 10, the fixed lever portion 411 and the shaft portion 412 are integrally formed. The fixed lever portion 411 has a hole 413 at the tip. The hole 413 penetrates the distal end of the fixed lever portion 411 in the vertical direction. As shown in FIG. 9, the blade link 23 is connected to the distal end of the fixed lever portion 411. The screw 414 inserted through the hole 413 connects the blade side link 23 to the distal end of the fixed lever portion 411 so as to be rotatable.

  The main body member 41 has a movable lever member 42 detachably provided below the shaft portion 412. The movable lever member 42 includes an extending portion 421, a frame portion 43, and a fixed portion 422. The movable lever member 42 attaches / detaches the frame portion 43 to / from the shaft portion 412.

  As shown in FIGS. 11 and 12, the frame portion 43 includes a first frame portion 431, a second frame portion 432, a slit groove 433, and a hole 434. The shape of the first frame portion 431 is cylindrical. The axial direction of the first frame portion 431 is directed in the vertical direction. The hole 434 is provided in the first frame portion 431. The hole 434 penetrates the first frame portion 431 in the axial direction. The inner diameter of the hole 434 is slightly larger than the diameter of the shaft portion 412 of the fixed lever portion 411. The second frame part 432 is provided on the outer peripheral wall of the first frame part 431. The second frame portion 432 is substantially cylindrical and extends in a direction orthogonal to the direction in which the hole 434 extends.

  The slit groove 433 is provided over the first frame portion 431 and the second frame portion 432. The slit groove 433 extends along the axial direction of the first frame portion 431, in other words, along the direction in which the hole 434 extends. The slit groove 433 has a slit shape. Two wall surfaces 435 forming the slit groove 433 are opposed to each other. The first frame part 431 side of the slit groove 433 communicates with the hole 434 and forms a gap in the first frame part 431. The slit groove 433 divides the second frame portion 432 into two parts. Each of the two portions of the second frame portion 432 faces each other with the slit groove 433 interposed therebetween. As shown in FIG. 12, one of the two portions of the second frame portion 432 includes a screw hole 436 extending in the axial direction. The screw hole 436 extends in a direction orthogonal to the direction in which the hole 434 of the first frame portion 431 extends.

  As shown in FIG. 11, the fixing portion 422 is a screw and can be tightened into the screw hole 436 of the second frame portion 432. By tightening the fixing portion 422 in the screw hole 436, the width between the two wall surfaces 435 forming the slit groove 433 is narrowed. Therefore, the inner diameter of the hole 434 of the first frame portion 431 is reduced.

  The extending portion 421 extends from the side of the first frame portion 431 of the frame portion 43 opposite to the side where the second frame portion 432 is provided, in a direction orthogonal to the direction in which the hole 434 extends. The length of the extending portion 421 in the extending direction is substantially the same as the length of the fixing lever portion 411 (see FIG. 9) of the main body member 41 in the extending direction. The extending portion 421 has a hole 425 extending in the vertical direction at the tip. As shown in FIG. 9, the front end of the second link 22 is pivotally connected to the distal end of the extending portion 421. A screw 426 inserted through the hole 425 connects the front end of the second link 22 to the tip of the extending portion 421.

  When the movable lever member 42 is fixed to the main body member 41, the fixing portion 422 is fastened to the screw hole 436 while the shaft portion 412 of the fixing lever portion 411 is passed through the hole 434 of the first frame portion 431. In this case, since the inner diameter of the hole 434 is reduced, the inner peripheral surface of the hole 434 is in close contact with the outer peripheral surface of the shaft portion 412. The movable lever member 42 cannot rotate with respect to each other in a state in which the extending portion 421 extends in substantially the same direction as the direction in which the fixed lever portion 411 of the main body member 41 extends.

  The fixed member 44 is provided at the lower end of the shaft portion 412 of the main body member 41 and below the movable lever member 42 fixed to the shaft portion 412. The shape of the fixing member 44 is cylindrical. The size of the fixing member 44 in the radial direction is substantially the same as the size of the first frame portion 431 in the radial direction. The fixing member 44 includes a hole penetrating along the axis. The shaft portion 412 is inserted through the hole. As shown in FIG. 11, a plurality of screws 441 are inserted from the outer peripheral wall of the fixing member 44 toward the center. By tightening the screw 441, the tip of the screw 441 protrudes inward from the inner wall of the hole of the fixing member 44. The fixing member 44 is fixed to the shaft portion 412 by tightening the screw 441 in a state where the shaft portion 412 is inserted into the hole. The fixed member 44 restricts the downward movement of the movable lever member 42 disposed above.

  As shown in FIG. 4, the second bed portion 9 is provided with a through hole 923 extending in the vertical direction at a connection portion between the needle plate support portion 91 and the accommodating portion 92. The through hole 923 is provided on the left side of the throat plate support portion 91 from the substantially left and right center. The shaft portion 412 of the main body member 41 of the swing mechanism 40 is inserted into the through hole 923. The through hole 923 supports a portion of the shaft portion 412 between the fixed lever portion 411 and the movable lever member 42 so as to be rotatable. Therefore, the fixed lever portion 411 and the movable lever member 42 of the swing mechanism 40 can swing. The fixed lever portion 411 is located at the upper end of the through hole 923, and the movable lever member 42 is located at the lower end of the through hole 923. The fixed lever portion 411 and the movable lever member 42 sandwich the second bed portion 9 from the vertical direction of the through hole 923. The lower surface of the movable lever member 42 is disposed at substantially the same height as the lower side surface of the housing portion 92. The extending portion 421 extends rightward from the shaft portion 412, and the tip is disposed in front of the front end of the link disposing portion 921. The second link 22 extends in a straight line along the link placement portion 921, and the front end projects forward from the front end of the link placement portion 921. The front end of the second link 22 is connected to the tip of the extending portion 421.

  As shown in FIG. 3, the fixing lever portion 411 is located inside the connecting portion between the needle plate support portion 91 and the accommodating portion 92. The fixed lever portion 411 extends rightward from the shaft portion 412, and the tip is located above the lower shaft 7. The blade side link 23 extends forward from the distal end of the fixed lever portion 411, and is located in the needle plate support portion 91 and at the upper right of the lower shaft 7.

  As shown in FIG. 13, the shape of the blade side link 23 is a plate shape long in the front-rear direction. The blade side link 23 extends in the horizontal direction, bends obliquely downward and forward in the vicinity of the front end, and further bends in the horizontal direction and extends forward. The front end of the blade side link 23 is located above the shuttle mechanism 11. A thread cutting blade 16 is provided in the vicinity of the front end of the blade side link 23. The thread cutting blade 16 is located above the shuttle mechanism 11 and below the needle plate 12. The thread cutting blade 16 includes a fixed blade 17 and a movable blade 18. The front end of the blade side link 23 is connected to the movable blade 18.

  The structure of the thread cutting blade 16 will be described with reference to FIGS. 14 to 16 are different in the rotating state of the movable blade 18. Hereinafter, the state of the movable blade 18 illustrated in FIG. 14 is referred to as a “first state”, the state of the movable blade 18 illustrated in FIG. 15 is referred to as a “second state”, and the state of the movable blade 18 illustrated in FIG. Three states.

  The fixed blade 17 is fixed to the lower surface of the needle plate 12 and the left side of the needle hole (not shown). The fixed blade 17 includes a base end portion 17A, an extending portion 17B, and a blade portion 17C. The shape of the base end portion 17A and the extending portion 17B is a plate shape. The proximal end portion 17 </ b> A includes two long holes 171. The upper surface of the base end portion 17A is in contact with the lower surface of the needle plate 12. The screw 172 is inserted into each of the two long holes 171 and fixed to the needle plate 12. The screw 172 fixes the fixed blade 17 to the needle plate 12. The fixed blade 17 can change the fixing position with respect to the needle plate 12 within the range of the length of the long hole 171 in the longitudinal direction. The extending portion 17B slightly extends downward from the right end of the base end portion 17A, and extends substantially horizontally rearward at the lower end. The extending portion 17B is located below the proximal end portion 17A with respect to the needle plate 12. The rear end of the extended portion 17B protrudes to the vicinity of the needle plate 12 below the needle hole. The extending portion 17B is provided with a blade portion 17C at the rear end. The blade portion 17C has a sharp tip, and can cut the yarn at the position of the blade portion 17C. The fixed blade 17 can change the position of the blade portion 17 </ b> C by changing the fixed position with respect to the needle plate 12 within the range of the length of the long hole 171 in the longitudinal direction.

  The movable blade 18 is disposed on the right side of the fixed blade 17. The movable blade 18 includes a circular plate-shaped main body 181, a protrusion 182 that protrudes from the main body 181 on one side, and a protrusion 183 that protrudes on the other side. The main body 181 is provided with a hole 184 substantially at the center. As shown in FIG. 13, the shaft 191 is disposed on the right side of the fixed blade 17 and is inserted into the hole 184 from below. The movable blade 18 is rotatable about the shaft 191 as a fulcrum. As shown in FIGS. 14 to 16, the protrusion 183 has a hole 185 at the end in the protrusion direction that extends on the opposite side of the main body 181. The pin 192 is inserted into a hole and a hole 185 provided at the front end of the blade side link 23 to connect the movable blade 18 and the blade side link 23 so as to be rotatable. The movable blade 18 rotates as the blade side link 23 moves in the extending direction, and the protrusion 182 swings about the shaft 191 as a fulcrum.

  The state of the movable blade 18 when the blade side link 23 moves rearward is the first state (see FIG. 14). The state of the movable blade 18 when the blade-side link 23 moves to the front and rear substantially center is the second state (see FIG. 15). The state of the movable blade 18 when the blade side link 23 moves forward is the third state (see FIG. 16).

  As shown in FIG. 14, in the first state, the protrusion 182 is located in front of the main body 181, and the protrusion 183 is located behind the main body 181. The protruding portion 182 is spaced forward from the extending portion 17B of the fixed blade 17. As shown in FIG. 15, in the second state, the main body 181 and the protrusions 182 and 183 are aligned in the left-right direction. The protruding portion 182 is located below the extending portion 17B and the blade portion 17C of the fixed blade 17. The protruding portion 182 contacts the blade portion 17C from below. As shown in FIG. 16, in the third state, the protrusion 182 is located behind the main body 181, and the protrusion 183 is located in front of the main body 181. The protruding portion 182 is separated rearward from the extending portion 17 </ b> B of the fixed blade 17.

  The projecting portion 182 includes a first side 182A, a second side 182B, a third side 182D, and a fourth side 182E on the outer peripheral side in the projecting direction extending on the opposite side to the main body unit 181. The first side 182 </ b> A is a side closer to the fixed blade 17 in the first state (see FIG. 14) among the two sides extending in the protruding direction of the protruding portion 182. The first side 182A extends in a direction intersecting with the protruding direction of the protruding portion 182 and in a direction from the inside toward the outside. The second side 182B is adjacent to the tip side of the first side 182A. The second side 182B protrudes in the swing direction when the protrusion 182 swings from the first state to the third state, and the tip is sharp. The fourth side 182E is the side that is separated from the fixed blade 17 in the first state, out of the two sides that extend in the protruding direction of the protruding portion 182. The fourth side 182E is bent toward the second side 182B. The third side 182D is provided on the side between the second side 182B and the fourth side 182E, and is curved to the side opposite to the main body 181.

  The protrusion 182 includes a hole 182C and a recess 182F. The hole 182C is a through hole provided inside the second side 182B and penetrating in the vertical direction. The concave portion 182F is a concave groove provided on the upper surface of the protruding portion 182. The recess 182F extends from the fourth side 182E toward the hole 182C.

  An operation in which the sewing machine 1 cuts the yarn with the yarn cutting blade 16 will be described. When the sewing machine 1 performs sewing, the plunger 732 of the solenoid 73 moves forward as shown in FIG. The drive lever 72 moves forward along the shaft 74 by the biasing force of a spring provided on the shaft 74. The protrusion 72A of the drive lever 72 is separated from the cam groove 71A. Therefore, the drive lever 72 does not rotate even when the upper shaft 6 rotates. In this state, the first link 21 is stationary while being moved upward by the biasing force of the spring attached to the rotating portion 241.

  As shown in FIG. 17, as the first link 21 moves upward, the connection portion 24 rotates counterclockwise as viewed from the right side with the shaft portion 242 as a fulcrum. As the connecting portion 24 rotates, the tip end of the first arm portion 243 tilts slightly upward from the horizontal direction, and the tip end of the second arm portion 244 tilts slightly rearward from the vertical direction. Therefore, the 2nd link 22 stops in the state which moved back. As shown in FIG. 18, as the second link 22 moves rearward, the swing mechanism 40 rotates counterclockwise in plan view with the shaft portion 412 as a fulcrum. The distal end of the fixed lever portion 411 and the distal end of the extending portion 421 are stationary while swinging backward. Therefore, the blade side link 23 stops in a state of moving backward. As the blade side link 23 moves rearward, the movable blade 18 rotates about the shaft 191 and stops in the first state (see FIG. 14).

  When the sewing machine 1 finishes sewing and is instructed to cut the thread, the plunger 732 moves rearward as shown in FIG. The drive lever 72 moves rearward along the shaft 74 against the biasing force of the spring. The protrusion 72A of the drive lever 72 engages with the cam groove 71A. Therefore, as the upper shaft 6 rotates, the projecting portion 72A moves in the vertical direction along the cam groove 71A, and the right end of the drive lever 72 swings up and down around the shaft 74 as a fulcrum.

  First, the right end of the drive lever 72 swings downward. As the right end of the drive lever 72 moves downward, the first link 21 moves downward. As shown in FIG. 19, as the first link 21 moves downward, the connection portion 24 rotates clockwise about the shaft portion 242 as a fulcrum. As the connecting portion 24 rotates, the tip end of the first arm portion 243 tilts slightly downward from the horizontal direction, and the tip end of the second arm portion 244 tilts slightly forward from the vertical direction. Therefore, the second link 22 moves forward. As shown in FIG. 20, as the second link 22 moves forward, the swing mechanism 40 rotates clockwise in plan view with the shaft portion 412 as a fulcrum. The distal end of the fixed lever portion 411 and the distal end of the extending portion 421 swing forward. Therefore, the blade side link 23 moves forward. As the blade side link 23 moves forward, the movable blade 18 rotates about the shaft 191 as a fulcrum. The state of the movable blade 18 changes from the first state (see FIG. 14) to the third state (see FIG. 16) through the second state (see FIG. 15).

  At this time, the upper thread extending downward from the sewing needle (not shown) through the needle hole (not shown) forms a loop below the needle hole. The side of the upper thread loop opposite to the side extending toward the sewing needle extends through the needle hole toward the cloth on the needle plate 12. The lower thread extending from the cloth on the needle plate 12 extends through the needle hole to the shuttle mechanism 11 below the thread cutting blade 16. When the movable blade 18 rotates from the first state (see FIG. 14) to the second state (see FIG. 15), the protrusion 182 moves from the front to the rear. The second side 182B passes under the needle hole from the front toward the rear, and enters the upper thread loop. Thereafter, the side of the upper thread loop extending toward the sewing needle is hooked on the first side 182A.

  Furthermore, the movable blade 18 rotates from the second state (see FIG. 15) to the third state (see FIG. 16). The first side 182A further moves rearward with the upper thread hooked, and guides the side of the upper thread loop extending toward the sewing needle to the rear. When the movable blade 18 is rotated to the third state (see FIG. 16), the side of the upper thread loop that extends toward the sewing needle contacts the first side 182A of the protrusion 182 and passes upward through the needle hole. It will be in the extended state.

  Next, the right end of the drive lever 72 moves upward as the cam plate 71 rotates. The first link 21 moves upward, and the second link 22 moves backward. The swing mechanism 40 rotates with the shaft portion 412 as a fulcrum, and the distal end of the fixed lever portion 411 and the distal end of the extending portion 421 swing backward. The blade side link 23 moves backward. The movable blade 18 rotates about the shaft 191 and the state of the movable blade 18 returns from the third state (see FIG. 16) to the first state (see FIG. 16) through the second state (see FIG. 15).

  In the process in which the state of the movable blade 18 returns from the third state (see FIG. 16) to the second state (see FIG. 15), the bent portion provided on the fourth side 182E extends toward the cloth in the loop of the upper thread. The side and lower thread are guided to the center of the fourth side 182E. The side of the upper thread loop extending toward the cloth and the lower thread extend from the fourth side 182E toward the hole 182C along the recess 182F. When the state of the movable blade 18 rotates from the second state to the first state, the blade portion 17C of the fixed blade 17 and the hole 182C of the movable blade 18 overlap in the vertical direction. The blade portion 17C and the hole 182C sandwich the side of the upper thread loop that extends toward the cloth and the lower thread. The blade portion 17C cooperates with the movable blade 18 to cut the side of the upper thread loop extending toward the cloth and the lower thread. Further, the movable blade 18 rotates until it reaches the first state. The movable blade 18 returns to the original state (first state), and the cutting of the yarn is finished.

  In this embodiment, the movable lever member 42 is loosely fixed to the main body member 41, and the frame portion 43 and the shaft portion 412 are relatively rotated to thereby extend the extending portion 421 and the main body member 41. The extending direction of the fixed lever portion 411 can be different. By changing the extending direction of the extending portion 421 and the extending direction of the fixed lever portion 411, the driving range of the thread cutting blade 16 changes. For example, when the direction in which the fixed lever portion 411 extends is shifted in the clockwise direction in plan view with respect to the direction in which the extending portion 421 extends, the blade side link 23 moves forward. As indicated by the one-dot chain line in FIG. 21, when the blade side link 23 moves forward, the movable blade 18 rotates clockwise in plan view with the shaft 191 as a fulcrum, and the protrusion 182 moves in the direction of the second state. . That is, the driving range of the movable blade 18 that is driven from the first state to the third state is changed, and the timing for cutting the yarn is changed in cooperation with the blade portion 17C. Therefore, the sewing machine 1 can appropriately adjust the timing for cutting the yarn by adjusting the driving range of the movable blade 18.

  As described above, in the sewing machine 1, the through hole 923 rotatably supports the shaft portion 412 between the fixed lever portion 411 and the movable lever member 42. In the sewing machine 1, when the thread cutting blade 16 cuts the thread, a force acts on both ends of the swing mechanism 40 provided with the fixed lever portion 411 and the movable lever member 42. Since the forces acting on the swing mechanism 40 are balanced, the position of the shaft portion 412 is stable, and the swing of the swing mechanism 40 is stable. Therefore, since the sewing machine 1 appropriately drives the thread cutting blade 16 as the swing mechanism 40 swings, the thread can be cut appropriately.

  The sewing machine 1 can be adjusted to a plurality of states in which the extending direction of the extending portion 421 is different from the main body member 41 by rotating the frame portion 43 of the movable lever member 42 with respect to the shaft portion 412. The fixed member 44 can fix the movable lever member 42 to the main body member 41 in a plurality of states in which the extending portions 421 extend in different directions with respect to the main body member 41. The swinging mechanism 40 changes its swinging range according to the direction in which the extending portion 421 extends, and the driving range of the movable blade 18 changes. Therefore, the sewing machine 1 can easily adjust the driving range of the movable blade 18 by adjusting the extending direction of the extending portion 421 relative to the main body member 41. Therefore, the sewing machine 1 can easily adjust the driving range of the movable blade 18 so that the timing at which the movable blade 18 cuts the yarn in cooperation with the fixed blade 17 is appropriate.

  The diameter of the hole 431 can be adjusted by adjusting the degree to which the sewing machine 1 tightens the fixing portion 422 with respect to the screw hole 436. The sewing machine 1 can be adjusted to a plurality of states in which the extending direction of the extending portion 421 differs from the main body member 41 only by loosening the fixing portion 422. The sewing machine 1 can fix the movable lever member 42 to the main body member 41 simply by tightening the fixing portion 422. Therefore, the operator can easily change the extending direction of the extending portion 421 of the movable lever member 42 with respect to the main body member 41.

  In the sewing machine 1, the fixed member 44 suppresses the vertical movement of the movable lever member 42 in a state where the movable lever member 42 is not fixed to the main body member 41. The movable lever member 42 prevents the position of the shaft portion 412 from shifting in the vertical direction even if the fixing to the main body member 41 is loosened when the extending direction of the extending portion 421 is adjusted. Therefore, the operator can reliably connect the movable lever member 42 to a predetermined position of the main body member 41 when adjusting the extending direction of the extending portion 421.

  In addition, this invention is not limited to the said embodiment, A various change is possible. In the above embodiment, the second link 22 is connected to the movable lever member 42 of the swing mechanism 40, and the blade side link 23 is connected to the fixed lever portion 411. In the sewing machine 1, the second link 22 may be connected to the fixed lever portion 411 of the swing mechanism 40, and the blade side link 23 may be connected to the movable lever member 42.

  A modification of the present invention will be described with reference to FIG. The swing mechanism 40 in the modification is different from the above embodiment in that the fixed lever portion 411 of the main body member 41 is provided at the lower end of the shaft portion 412 and the movable lever member 42 is fixed to the upper end of the shaft portion 412. In this case, the fixed member 44 regulates the downward movement of the movable lever member 42 by being fixed to the upper side of the shaft portion 412 and below the movable lever member 42. The shapes of the fixed lever portion 411 and the shaft portion 412 of the main body member 41, the protruding direction of the fixed lever portion 411, the extending direction of the shaft portion 412 with respect to the second link 22, and the structure of the movable lever member 42 are the same as in the above embodiment. Therefore, explanation is omitted.

  The shaft portion 412 of the main body member 41 of the swing mechanism 40 is inserted into a through hole 923 provided at a connection portion between the needle plate support portion 91 and the accommodating portion 92. The through hole 923 supports a portion of the shaft portion 412 between the fixed lever portion 411 and the movable lever member 42 so as to be rotatable. The fixed lever portion 411 is disposed at substantially the same height as the lower surface of the accommodating portion 92. The fixed lever portion 411 extends rightward from the shaft portion 412, and the tip is disposed in front of the front end of the link placement portion 921. The distal end of the fixed lever portion 411 is connected to the front end of the second link 22.

  The extending portion 421 of the movable lever member 42 is disposed inside the connection portion between the needle plate support portion 91 and the accommodating portion 92. The extending portion 421 extends to the right from the shaft portion 412, and the tip is located on the upper right side of the lower shaft 7. The blade side link 23 extends forward from the distal end of the extending portion 421 and is located in the needle plate support portion 91 and on the upper right side of the lower shaft 7.

  As described above, also in the modified example, the sewing machine 1 supports the shaft portion 412 between the fixed lever portion 411 and the movable lever member 42 so that the through hole 923 can rotate as in the above-described embodiment. In the sewing machine 1, when the thread cutting blade 16 cuts the thread, a force acts on both ends of the swing mechanism 40 provided with the fixed lever portion 411 and the movable lever member 42. Since the forces acting on the swing mechanism 40 are balanced, the swing of the swing mechanism 40 is stable. Therefore, since the sewing machine 1 appropriately drives the thread cutting blade 16 as the swing mechanism 40 swings, the thread can be cut appropriately.

  The fixed lever portion 411 of the swing mechanism 40 and the extending portion 421 of the movable lever member 42 may protrude in opposite directions with respect to the shaft portion 412. The fixed lever portion 411 and the extending portion 421 need only protrude in a direction intersecting the shaft portion 412, and may not protrude in the vertical direction with respect to the shaft portion 412.

  The method for fixing the movable lever member 42 to the shaft portion 412 is not limited to the above embodiment. For example, a through hole extending toward the center may be provided in the first frame portion 431 of the movable lever member 42. A screw may be inserted through the through hole. The tip of the screw may be able to protrude into the hole 431. The movable lever member 42 may be fixed to the shaft portion 412 by tightening a screw inserted through the through hole.

  Instead of the fixing member 44, a groove may be provided in the shaft portion 412. The vertical position of the movable lever member 42 may be regulated by supporting the first frame portion 431 of the movable lever member 42 from below.

  The second link 22 corresponds to the “upper shaft side link” of the present invention.

DESCRIPTION OF SYMBOLS 1 Sewing machine 2 Bed part 3 Leg part 4 Arm part 6 Upper shaft 7 Lower shaft 8 First bed part 9 Second bed part 10 Gear mechanism 11 Hook mechanism 12 Needle plate 16 Thread trimmer 17 Fixed blade 18 Movable blade 20 Link mechanism 21 First link 22 Second link 23 Blade side link 24 Connecting portion 40 Oscillating mechanism 41 Main body member 42 Movable lever member 43 Frame portion 44 Fixing member 411 Fixing lever portion 412 Shaft portion 421 Extension portion 422 Fixing portion 425 Hole 431 First One frame part 432 Second frame part 433 Cutting groove 434 Hole 436 Screw hole 921 Link arrangement part

Claims (5)

The bed section,
A pedestal that extends upward from one end of the bed,
An arm portion extending from the upper end of the pedestal portion facing the bed portion, and having an upper shaft inside;
A thread cutting blade disposed on the other end of the bed part and below the needle plate to cut the thread;
In a sewing machine comprising a link mechanism that transmits the rotational force of the upper shaft to the thread cutting blade,
The link mechanism is
An upper shaft side link that moves in the stretching direction as the upper shaft rotates,
A swing mechanism connected to the upper shaft side link and swinging as the upper shaft side link moves;
A blade-side link having one end connected to the swing mechanism and the other end extending to the thread cutting blade and moving in the extending direction as the swing mechanism swings;
The swing mechanism is
A shaft portion extending in a direction intersecting the extending direction of the upper shaft side link, and a fixing lever portion extending from one end portion of the shaft portion in a direction intersecting the axial direction of the shaft portion and connected to the blade side link A body member comprising:
A movable lever member connected to the other end portion of the shaft portion of the main body member so as to be rotatable, extending in a direction intersecting the axial direction, and connected to the upper shaft side link;
The swing mechanism is a sewing machine that supports the bed portion so as to be swingable between the fixed lever portion and the movable lever member in the shaft portion. The movable lever member is
An extending portion connected to the other end portion of the shaft portion and the upper shaft side link and extending in a direction intersecting the axial direction of the shaft portion;
A frame portion that is connected to an end portion on the shaft portion side of the extension portion and includes a hole that rotatably supports the extension portion on the shaft portion;
The sewing machine according to claim 1, further comprising a fixing portion that fixes the frame portion to the shaft portion so that the frame portion cannot rotate. The frame is
A cylindrical first frame part having the hole on the inner peripheral surface, a second frame part provided on the outer periphery of the cylinder of the first frame part, and the first frame part and the second frame part A slit groove provided and extending along the axis of the hole,
The second frame part is
A screw hole extending in a direction orthogonal to the extending direction of the slit groove and penetrating the slit groove;
The fixing part is
A screw that narrows the width of the slit groove by inserting into the screw hole and penetrating the slit groove;
By inserting the screw into the screw hole and narrowing the width of the slit groove, the inner diameter of the hole of the first frame portion is narrowed and closely contacted with the outer peripheral surface of the shaft portion to be fixed unrotatable. The sewing machine according to claim 2, wherein the sewing machine is characterized in that: The swing mechanism is
The sewing machine according to claim 1, further comprising a fixing member that fixes the movable lever member to the opposite side of the fixed lever portion with respect to the shaft portion of the main body member. The bed section,
A pedestal that extends upward from one end of the bed,
An arm portion extending from the upper end of the pedestal portion facing the bed portion, and having an upper shaft inside;
A thread cutting blade disposed on the other end of the bed part and below the needle plate to cut the thread;
In a sewing machine comprising a link mechanism that transmits the rotational force of the upper shaft to the thread cutting blade,
The link mechanism is
An upper shaft side link that moves in the stretching direction as the upper shaft rotates,
A swing mechanism connected to the upper shaft side link and swinging as the upper shaft side link moves;
A blade-side link having one end connected to the swing mechanism and the other end extending to the thread cutting blade and moving in the extending direction as the swing mechanism swings;
The swing mechanism is
A shaft portion extending in a direction intersecting the extending direction of the upper shaft side link, and a fixing lever extending from one end portion of the shaft portion in a direction intersecting the axial direction of the shaft portion and connected to the upper shaft side link A body member having a portion;
A movable lever member connected to the other end portion of the shaft portion of the main body member so as to be rotatable, extending in a direction intersecting the axial direction, and connected to the blade side link;
The swing mechanism is a sewing machine that supports the bed portion so as to be swingable between the fixed lever portion and the movable lever member in the shaft portion.

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