sewing machine

Abstract

To provide a sewing machine that can be downsized in an axial direction of a hook shaft.SOLUTION: A shuttle mechanism is moved by a moving mechanism in right and left directions through a hook shaft 37. A transfer mechanism 21 has a pulley 22 and a spline nut 34. A hole 26 is formed on the pulley 22. The spline nut 34 is entirely buried in the hole 26. A through hole 35 is formed at a center of a bottom face of the spline nut 34. An internal tooth 36 is formed in parallel with the right-left directions on an inner peripheral surface specified by the through hole 35. An external tooth 38 is formed in parallel with the right-left directions on a lateral face of the hook shaft 37. The external tooth 38 is engaged with the internal tooth 36. The pulley 22, the spline nut 34, and the hook shaft 37 are driven by a sewing machine motor to integrally rotate around a shaft center. The external tooth 38 is guided to the internal tooth 36 when the hook shaft 37 is moved in the right-left directions by the moving mechanism.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a sewing machine. [Background technology]

[0002] There is a known sewing machine that moves a rotary hook horizontally to adjust the clearance between the sewing needle and the rotary hook's point. The rotary hook movement adjustment device for a sewing machine described in Patent Document 1 includes a stepping motor and an eccentric pin mechanism. When the stepping motor is driven, the rotational drive of the stepping motor is converted into forward and backward drive by the eccentric pin mechanism. The eccentric pin mechanism engages with a sleeve. The sleeve pivotally supports the rotary hook shaft. The rotary hook is moved forward and backward via the sleeve by the drive of the rotary hook movement adjustment device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-226285 Summary of the Invention [Problem to be solved by the invention]

[0004] In a sewing machine, the rotary hook rotates the rotary hook shaft around its axis so that the rotary hook can capture the thread loop. The sewing machine is equipped with a transmission mechanism that transmits external power to rotate the rotary hook shaft. The rotary hook shaft is provided with a transmission mechanism that transmits external power and a sleeve that transmits the drive of the stepping motor of the rotary hook movement adjustment device. Therefore, the rotary hook shaft becomes longer in the axial direction, which may result in an increase in the size of the sewing machine.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide a sewing machine that can be made smaller in size in the axial direction of the shuttle shaft. [Means for solving the problem]

[0006] A sewing machine according to one aspect of the present invention includes a shuttle mechanism that captures an upper thread passed through a sewing needle that moves up and down and intertwines it with a bobbin thread; a shuttle shaft that extends in an axial direction that intersects the up-and-down direction and is rotatable about an axis parallel to the axial direction and supports the shuttle; external teeth that are formed on the shuttle shaft and that are formed in a direction parallel to the axial direction; a moving mechanism that moves the shuttle in the axial direction via the shuttle shaft; a spline nut into which the shuttle shaft is inserted and that has internal teeth on its inner peripheral surface that mesh with the external teeth; and a rotor that has a hole that opens in the axial direction and that transmits external power to rotate about the axis, wherein at least a portion of the spline nut is embedded in the hole.

[0007] In a sewing machine, rotation of the rotating body causes the shuttle shaft to rotate about an axis parallel to the axial direction via the spline nut. When the moving mechanism moves the shuttle mechanism in the axial direction via the shuttle shaft, the spline nut guides the shuttle shaft in the axial direction with its internal teeth. At least a portion of the spline nut is embedded in the hole of the rotary shaft. Therefore, the sewing machine can be made compact in the axial direction while still having a mechanism for rotating the shuttle shaft about an axis parallel to the axial direction and a moving mechanism for moving the shuttle shaft in the axial direction.

[0008] The moving mechanism may include a motor and a brake mechanism that suppresses rotation of the motor's rotary shaft when the motor is not energized. In the sewing machine, when the motor is not energized, the brake mechanism suppresses rotation of the motor's rotary shaft, thereby suppressing axial movement of the shuttle mechanism by the moving mechanism. Therefore, when there is no need to move the shuttle mechanism by the moving mechanism in the sewing machine, the axial movement of the shuttle mechanism can be easily suppressed by not energizing the motor.

[0009] The moving mechanism may include a motor and a cam that rotates when driven by the motor and has a second hole that opens in a second intersecting direction that intersects with the rotation shaft of the motor. Because the moving mechanism includes the cam, when there is no need to move the shuttle mechanism by the moving mechanism, the rotation shaft of the motor rotates less easily than in a case where there is no cam. Therefore, the load on the rotation shaft of the motor can be reduced when there is no need to move the shuttle mechanism by the moving mechanism.

[0010] The movement mechanism may include a motor, a first link member that swings when driven by the motor, a second link member that swings when the first link member swings, and an eccentric pin that connects the first link member to the first link member. In the sewing machine, the first link member and the second link member are connected by the eccentric pin. By rotating the eccentric pin, the position of the fulcrum for the swing of the second link member relative to the first link member can be adjusted. Therefore, the sewing machine can adjust the axial movement of the shuttle mechanism by the movement mechanism with a simple configuration.

[0011] The movement mechanism may include a motor, a locking portion that locks onto the shuttle shaft, a cross-engagement portion formed on the locking portion and extending in a direction crossing the axial direction, and a cross-engaged portion that moves in the cross direction guided by the cross-engagement portion when driven by the motor and transmits the driving force of the motor in the axial direction to the locking portion. The sewing machine converts the rotational motion of the motor's rotating shaft into the axial direction by the cross-engagement portion moving while being guided by the cross-engagement portion. The shuttle shaft moves in the axial direction via the locking portion when driven by the motor. Therefore, the sewing machine can move the shuttle shaft in the axial direction with a simple configuration.

[0012] The movement mechanism may include a bearing portion that supports the shuttle shaft rotatably about the axis, and an axis engaging portion that extends in the axial direction of the bearing portion, one end of which is fixed to a machine frame of the sewing machine, extends toward the axis engaging portion, and the other end of which is engaged with the axis engaging portion. The bearing portion may rotate slightly around an axis parallel to the axial direction due to friction with the shuttle shaft. In the sewing machine, engagement between the axis engaging portion and the axis engaged portion, one end of which is fixed to the machine frame of the sewing machine, prevents the bearing portion from rotating around the axis parallel to the axial direction. Therefore, the sewing machine can prevent the bearing portion from rotating around the axis parallel to the axial direction with a simple configuration. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of the sewing machine 1 on the table 100. [Figure 2] FIG. [Figure 3] FIG. 2 is a perspective view of the shuttle mechanism 18, the shuttle support portion 20, and the moving mechanism 60. [Figure 4] FIG. 2 is a plan view of the shuttle mechanism 18, the shuttle support portion 20, and the moving mechanism 60. [Figure 5] 5 is a cross-sectional view taken along line AA in FIG. 4, viewed from the direction of the arrow. [Figure 6] FIG. 2 is an exploded perspective view of the shuttle mechanism 18, the shuttle support portion 20, and the block member 83. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] 15 is a cross-sectional view taken along line BB in FIG. 14, viewed from the direction of the arrow. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to the drawings. In the following description, arrows in the drawings will be used to indicate left and right, front and rear, and top and bottom.

[0015] The sewing machine 1 is a gate-type sewing machine capable of sewing a workpiece. As shown in Fig. 1, the sewing machine 1 has a bed 2, a pair of pillars 3 and 4, a feed mechanism (not shown), a holding mechanism 8, a beam 5, a needle bar mechanism 106, and a shuttle container 10.

[0016] The bed 2 has a base 121, a pair of front and rear rails, and a frame 122. The base 121 is substantially rectangular. The upper surface of the base 121 forms a flat holding surface 121A that extends horizontally. A holding plate 123 that extends forward along the holding surface 121A is provided at the front end of the base 121. A bellows 121R that extends in the front-rear direction is provided near the right end of the holding surface 121A. A bellows 121L that extends in the front-rear direction is provided near the left end of the holding surface 121A. The pair of front and rear rails are provided below the bellows 121L, 121R. The front and rear rails support a holding mechanism 8 (described below) so that it can move in the front-rear direction. The bellows 121R, 121L expand and contract in response to the reciprocating movement of the holding mechanism 8 in the front-rear direction. The frame 122 is a lattice-shaped structure that supports the base 121 from below. In the bed portion 2, a lower rail (not shown) and a shuttle accommodating portion 10 (described later) are disposed below the base portion 121. The lower rail extends in the left-right direction and supports the shuttle accommodating portion 10 so that it can move in the left-right direction.

[0017] The pair of pillars 3, 4 are each shaped like a substantially rectangular pillar. Pillar 3 extends upward from a position at the right end of base 121 of bed 2 and forward of the center in the front-to-rear direction. Pillar 3 is located to the right of bellows 121R in the left-to-right direction. Pillar 4 extends upward from a position at the left end of base 121 of bed 2 and forward of the center in the front-to-rear direction. Pillar 4 is located to the left of bellows 121L in the left-to-right direction. Pillars 3, 4 are spaced apart in the left-to-right direction.

[0018] The beam 5 is installed between the pillars 3 and 4. The beam 5 extends in the left-right direction between the pair of pillars 3 and 4. The beam 5 has a housing 151. The housing 151 extends between the upper and rear ends of the pillars 3 and 4. An upper rail is provided in the space surrounded by the pillars 3 and 4 and the housing 151. The upper rail is installed between the pillars 3 and 4. The upper rail supports the needle bar mechanism 106 so that it can move left-right. A bellows 152 is installed across the front ends of the pillars 3 and 4 and the housing 151, and across both the left and right ends of the needle bar mechanism 106, which will be described later. The bellows 152 covers the front side of the upper rail.

[0019] The needle bar mechanism 106 is provided on the front side of the beam portion 5. The needle bar mechanism 106 is equipped with a needle bar (not shown). The needle bar extends in the vertical direction and a sewing needle can be attached to it. The needle bar is movable in the vertical direction. The needle bar mechanism 106 is movable in the left-right direction along an upper rail within the beam portion 5 and along the front end of the beam portion 5. The bellows 152 expands and contracts in response to the needle bar mechanism 106 moving back and forth in the left-right direction along the upper rail.

[0020] The feed mechanism moves the holding mechanism 8, which holds the workpiece, back and forth relative to the needle bar mechanism 106 and the shuttle container 10. The feed mechanism is equipped with connecting portions 211 and 212. The lower left end of the connecting portion 211 is disposed on the front-to-rear rail on the left side of the bed portion 2. The lower right end of the connecting portion 212 is disposed on the front-to-rear rail on the right side of the bed portion 2. The connecting portions 211 and 212 are connected to the holding mechanism 8. The holding mechanism 8 can hold the workpiece. The holding mechanism 8 has an upper frame 181, a lower frame 182, and air cylinders 183 and 184. The upper frame 181 and the lower frame 182 are rectangular frames in a plan view, and sandwich the workpiece between them. The upper frame 181 opens and closes up and down relative to the lower frame 182 using the air cylinders 183 and 184 as drive sources.

[0021] 2, the shuttle accommodating section 10 includes a lower machine frame 11, a sewing machine motor 6, a shuttle support section 20, a shuttle mechanism 18, and a moving mechanism 60. The lower machine frame 11 is box-shaped and accommodates the shuttle support section 20, the shuttle mechanism 18, and the moving mechanism 60.

[0022] The sewing machine motor 6 is provided at the lower end of the shuttle container 10. The rotary shaft of the sewing machine motor 6 extends in the left-right direction. A connecting pulley 12 is provided to the right of the sewing machine motor 6. The rotary shaft of the sewing machine motor 6 is fixed to the connecting pulley 12.

[0023] The connecting pulley 12 includes pulleys 14 and 15. The pulleys 14 and 15 are cylindrical. The axes of the pulleys 14 and 15 extend parallel to the left-right direction. The axes of the pulleys 14 and 15 are aligned. The diameter of the bottom surface of the pulley 14 is larger than the diameter of the bottom surface of the pulley 15. The pulley 15 is connected to the right end of the pulley 14. An endless belt 16 is wound around the pulley 14. The endless belt 16 is further wound around a pulley 22 (see Figure 3), described below, of the shuttle support portion 20. An endless belt (not shown) is wound around the pulley 15. The endless belt wound around the pulley 15 is further wound around a pulley fixed to the upper shaft. The rotation of the pulley 15 drives the endless belt, causing the upper shaft to rotate. The rotation of the upper shaft causes the needle bar and sewing needle to move up and down.

[0024] The structure of the shuttle support part 20 will be described with reference to Figures 3 to 7. The left end of the shuttle support part 20 supports the shuttle mechanism 18. The shuttle support part 20 includes a transmission mechanism 21, shuttle shafts 37 and 47 (see Figure 6), and a connecting clamp 39. As shown in Figures 5 and 7, the transmission mechanism 21 includes a pulley 22, a spline nut 34, and shaft support members 30 and 32.

[0025] The pulley 22 includes cylinders 23, 24, and 25. The axes of the cylinders 23, 24, and 25 extend parallel to the left-right direction. The axes of the cylinders 23, 24, and 25 are aligned. The diameter of the bottom surface of the cylinder 23 is larger than the diameter of the bottom surface of the cylinder 24. The diameter of the bottom surface of the cylinder 24 is larger than the diameter of the bottom surface of the cylinder 25. The cylinder 23 is connected to the right end of the cylinder 25. The cylinder 24 is connected to the right end of the cylinder 23.

[0026] External teeth 28 are formed on the side of cylinder 23 in a direction parallel to the left-right direction. Although not shown in Figures 3 to 7, an endless belt 16 is wound around external teeth 28 as shown in Figure 2. The belt is driven by the rotation of pulley 14, and pulley 22 rotates around the axis of cylinders 23, 24, and 25.

[0027] A hole 26 recessed to the left is formed in the center of the right face of cylinder 24. Hole 26 extends from the right face of cylinder 24 to the left end of cylinder 23. A hole 27 (see Figure 5) recessed to the right is formed in the center of the left face of cylinder 25. Hole 27 extends from the left face of cylinder 25 to the left end of cylinder 23. The diameter of hole 27 is smaller than the diameter of hole 26 and is the same size as the diameter of shuttle shaft 37. Holes 26 and 27 communicate at the left end of cylinder 23.

[0028] As shown in Figure 7, the spline nut 34 is cylindrical. The axis of the spline nut 34 extends parallel to the left-right direction. The axis of the spline nut 34 coincides with the axis of the pulley 22. The diameter of the bottom surface of the spline nut 34 is the same as the diameter of the hole 26. The entire spline nut 34 is embedded in the hole 26. A through hole 35 is formed in the center of the bottom surface of the spline nut 34, penetrating the spline nut 34 in the left-right direction. Internal teeth 36 are formed on the inner circumferential surface of the spline nut 34 defined by the through hole 35, in a direction parallel to the left-right direction.

[0029] The support members 30, 32 are cylindrical. The axes of the support members 30, 32 extend parallel to the left-right direction. The axes of the support members 30, 32 coincide with the axis of the pulley 22. The diameters of the support members 30, 32 are the same as the diameter of the cylinder 23. The support member 30 is formed in the lower machine frame 11 and is inserted into a through-hole (not shown) that passes through the lower machine frame 11 in the left-right direction. The support member 32 is formed in the lower machine frame 11 and is inserted into a through-hole 110 (see Figure 2) that passes through the lower machine frame 11 in the left-right direction. The support members 30, 32 are rotatable with the lower machine frame 11 acting as a sliding bearing.

[0030] A through hole 31 is formed in the center of the bottom surface of the pivotal member 30, penetrating the pivotal member 30 in the left-right direction. The diameter of the through hole 31 is the same as the diameter of the cylinder 24. The cylinder 24 is inserted into the through hole 31. A through hole 33 is formed in the center of the bottom surface of the pivotal member 32, penetrating the pivotal member 32 in the left-right direction. The diameter of the through hole 33 is the same as the diameter of the cylinder 25. The cylinder 25 is inserted into the through hole 33. When the sewing machine motor 6 is driven, the pulley 22, spline nut 34, and pivotal members 30 and 32 of the transmission mechanism 21 rotate integrally about the axis.

[0031] As shown in Figures 5 to 7, the axis of shuttle shaft 37 extends parallel to the left-right direction. External teeth 38 are formed on the side surface of shuttle shaft 37 in a direction parallel to the left-right direction. From the right, shuttle shaft 37 passes through through hole 35, through hole 33, clamp 42, and block member 83 (described later). Clamp 42 is fixed to shuttle shaft 37 on the left side of cylinder 25.

[0032] The external teeth 38 of the shuttle shaft 37 mesh with the internal teeth 36 of the through hole 35. When the transmission mechanism 21 is rotated by the driving of the sewing machine motor 6, the shuttle shaft 37 rotates integrally with the transmission mechanism 21 about its axis. The external teeth 38 of the shuttle shaft 37 are guided by the internal teeth 36 of the through hole 35, and the shuttle shaft 37 can move in translation in the left-right direction.

[0033] 5, a connecting clamp 39 is fixed to the left end of the shuttle shaft 37. The connecting clamp 39 includes clamps 40 and 41. The clamp 40 is connected to the right end of the clamp 41. The left end of the shuttle shaft 37 is fixed by the clamp 40 of the connecting clamp 39.

[0034] As shown in Figures 5 and 6, the axis of shuttle shaft 47 extends parallel to the left-right direction. The axes of shuttle shafts 37, 47 are aligned. The right end of shuttle shaft 47 is fixed by clamp 41 of connecting clamp 39. A hole 48 recessed to the right is formed in the center of the left surface of shuttle shaft 47.

[0035] The shuttle shaft 47 is inserted through the support member 43. The support member 43 is cylindrical. The axis of the support member 43 extends parallel to the left-right direction. The axis of the support member 43 coincides with the axis of the shuttle shaft 47. The support member 43 is formed in the lower machine frame 11 and is inserted through a through hole 111 (see Figure 2) that passes through the lower machine frame 11 in the left-right direction. A through hole 44 that passes through the support member 43 in the left-right direction is formed in the center of the bottom surface of the support member 43. The diameter of the through hole 44 is the same as the diameter of the shuttle shaft 47. The shuttle shaft 47 is inserted through the through hole 44 of the support member 43. The support member 43 is fixed to the shuttle shaft 47. The support member 43 can rotate integrally with the shuttle shaft 47, with the lower machine frame 11 acting as a sliding bearing.

[0036] The right end of shuttle mechanism 18 is connected to shaft 19. Shaft 19 extends in the left-right direction. Shaft 19 is embedded in hole 48 of shuttle shaft 47 (see Figure 5). When transmission mechanism 21 rotates, shuttle mechanism 18 rotates about its axis via shuttle shafts 37 and 47. Below needle plate 13, shuttle mechanism 18 captures the loop of needle thread inserted into the sewing needle. In this way, sewing machine 1 forms a stitch on the fabric placed on needle plate 13.

[0037] The structure of the movement mechanism 60 will be described with reference to Figures 3, 4, and 8 to 13. The movement mechanism 60 moves the shuttle mechanism 18 left and right via the shuttle shaft 37. The movement mechanism 60 adjusts the left and right position of the shuttle mechanism 18 relative to the sewing needle that has passed through the needle eye. The movement mechanism 60 includes a stepping motor 50, a grooved cam 51, a fulcrum pin 61, a shoulder bolt 65, link members 68, 71, 77, an eccentric pin 72, a square piece 81, and a block member 83.

[0038] The stepping motor 50 is provided behind the shuttle mechanism 18 (see FIG. 4). The stepping motor 50 has a built-in electromagnetic brake that operates when not energized. As shown in FIG. 9, the rotating shaft 50A of the stepping motor 50 extends in the vertical direction. When not energized, the rotating shaft 50A is prevented from rotating around its axis by the electromagnetic brake. A grooved cam 51 is provided above the stepping motor 50. The rotating shaft 50A of the stepping motor 50 is fixed to the grooved cam 51.

[0039] As shown in Figure 11, the grooved cam 51 has a disk 52. The axis of the disk 52 extends parallel to the vertical direction. An annular groove 54 that is recessed upward is formed in the bottom surface of the disk 52. A cylinder 55 is provided at the center of a central portion 53 of the disk 52, which is defined inside the groove 54, and protrudes downward. The axis of the cylinder 55 extends parallel to the vertical direction. The axis of the cylinder 55 coincides with the axis of the disk 52. A hole 55A that is recessed upward is formed in the bottom surface of the cylinder 55. A rotating shaft 50A of a stepping motor 50 (see Figure 9) is embedded in the hole 55A. When the stepping motor 50 is driven, the grooved cam 51 rotates around the axis.

[0040] As shown in Figures 4 and 9, the fulcrum pin 61 is provided behind the shuttle mechanism 18 and in front of the grooved cam 51. The fulcrum pin 61 includes a fixed barrel 62 and a cantilever pin 63. The fixed barrel 62 is cylindrical. One end of the cantilever pin 63 is fixed to the fixed barrel 62. The shoulder bolt 65 is provided to the left and front of the fulcrum pin 61 and behind the shuttle support part 20. More specifically, the shoulder bolt 65 is provided behind the block member 83 through which the shuttle shaft 37 passes.

[0041] As shown in Figures 9 and 10, the link member 68 is a rod-shaped member extending horizontally from the fulcrum pin 61 toward the grooved cam 51. A through hole 68A that penetrates in the vertical direction is formed in the end of the link member 68 on the fulcrum pin 61 side. A cantilever pin 63 is inserted into the through hole 68A. The cantilever pin 63 is fixed to the lower machine frame 11 below the link member 68. The link member 68 is provided so as to be able to swing around the fulcrum pin 61. A through hole 68B that penetrates in the vertical direction is formed in the end of the link member 68 on the grooved cam 51 side. A pin 70 that extends in the vertical direction is inserted into the through hole 68B. The link member 68 fixes the lower end of the pin 70.

[0042] The link member 71 is a rod-shaped member extending from the grooved cam 51 to the right and front. In the left-right direction, a through hole 71A that penetrates in the vertical direction is formed at the end of the left side of the link member 71 (the grooved cam 51 side). A pin 70 is inserted into the through hole 71A above the link member 68. The link member 71 is provided so as to be able to swing around the pin 70. The pin 70 protrudes above the link member 71. The upper end of the pin 70 fits into the groove 54 of the grooved cam 51. A through hole 71B that penetrates in the vertical direction is formed at the end of the right side of the link member 71. An eccentric pin 72 is inserted into the through hole 71B.

[0043] 12 and 13, the eccentric pin 72 has cylinders 73, 74, and 75. The axes of the cylinders 73, 74, and 75 extend parallel to the vertical direction. The axes of the cylinders 73 and 74 are aligned. The axis C2 of the cylinder 75 is eccentric with respect to the axis C1 of the cylinder 74.

[0044] The diameter of the bottom surface of cylinder 73 is larger than the diameter of the bottom surface of cylinder 74. The diameter of the bottom surface of cylinder 74 is larger than the diameter of the bottom surface of cylinder 75. Cylinder 74 is connected to the upper end of cylinder 73. Cylinder 75 is connected to the upper end of cylinder 74. A groove 76 that is recessed downward is formed in the upper surface of cylinder 75. Groove 76 can be fitted with a tool such as a screwdriver.

[0045] As shown in Figures 4, 9 and 10, the link member 77 is a rod-shaped member bent into an L-shape in a plan view. The link member 77 has a base 78 and arms 79 and 80. The base 78 is cylindrical. The axis of the base 78 extends parallel to the vertical direction. A through hole 78A that penetrates in the vertical direction is formed in the bottom surface of the base 78. A shoulder bolt 65 is inserted into the through hole 78A. The lower end of the shoulder bolt 65 is fixed to the lower machine frame 11 below the base 78. The link member 77 is provided so as to be able to swing around the shoulder bolt 65.

[0046] Arm 79 is rod-shaped and extends from base 78 toward eccentric pin 72. A through-hole 79A that penetrates vertically is formed in the end of arm 79 on the eccentric pin 72 side. Eccentric pin 72 is inserted, from bottom to top, through through-hole 71B of link member 71 and through-hole 79A of arm 79. Cylinder 74 of eccentric pin 72 is inserted through through-hole 71B. Link member 71 fixes cylinder 74. Cylinder 75 of eccentric pin 72 is inserted through through-hole 79A. Arm 79 is provided so as to be able to swing around cylinder 75. In eccentric pin 72, axis C2 of cylinder 75 is eccentric with respect to axis C1 of cylinder 74. Therefore, when an operator rotates eccentric pin 72 with a tool or the like, the distance from through-hole 71A of link member 71 to through-hole 79A of arm 79 changes.

[0047] Arm 80 is rod-shaped and extends from base 78 toward shuttle support part 20. More specifically, arm 80 extends toward block member 83 through which shuttle shaft 37 passes. The extension direction of arm 80 is bent horizontally relative to the extension direction of arm 79. A through-hole 80A that penetrates in the vertical direction is formed in the end of arm 80 on the side of block member 83.

[0048] The square piece 81 is shaped like a rectangular parallelepiped. The square piece 81 is provided below the end of the arm 80 on the side of the block member 83. A screw hole 81A that is recessed downward is formed on the top surface of the square piece 81. The screw 82 is inserted from above through the through hole 80A in the arm 80 and through the washer 80B, and is screwed into the screw hole 81A in the square piece 81.

[0049] As shown in Figures 6 and 8, the block member 83 is in the shape of a rectangular tube. The axis of the block member 83 extends parallel to the left-right direction. A groove 85 that is U-shaped when viewed from the front is formed at the upper end of the block member 83. The groove 85 extends in the front-rear direction. The groove 85 is formed over the entire area of ​​the block member 83 in the front-rear direction. A rectangular piece 81 is fitted into the groove 85. The rectangular piece 81 is guided by the groove 85 and can slide in the front-rear direction.

[0050] A front surface 86 extending in the left-right and up-down directions is formed at the front end of the block member 83. A groove 87 recessed in an inverted C shape in a side view from the front surface 86 of the block member 83 is formed. The groove 87 is formed in the center of the front surface 86 in the up-down direction. The groove 87 extends in the left-right direction. The groove 87 is formed across the entire area of ​​the block member 83 in the left-right direction.

[0051] A hole 88 recessed to the left is formed in the center of the right side surface of block member 83. A rolling bearing 57 is embedded in hole 88 (see FIG. 5). The diameter of the inner ring of rolling bearing 57 is the same as the diameter of shuttle shaft 37. A hole 89 recessed to the right is formed in the center of the left side surface of block member 83. A rolling bearing 56 is embedded in hole 89 (see FIG. 5). The diameter of the inner ring of rolling bearing 56 is the same as the diameter of shuttle shaft 37. A through hole 84 penetrating block member 83 in the left-right direction is formed in the center of the bottom surfaces of holes 88 and 89. The diameter of through hole 84 is the same as the diameter of shuttle shaft 37.

[0052] 5, the shuttle shaft 37 is inserted through the rolling bearings 56, 57 and the through-hole 84 of the block member 83 between the clamp 42 and the connecting clamp 39 in the left-right direction. The frictional force acting between the shuttle shaft 37 and the rolling bearings 56, 57 allows the shuttle shaft 37 to move translationally in the left-right direction together with the block member 83. The rolling bearings 56, 57 allow the shuttle shaft 37 to rotate about its axis relative to the block member 83.

[0053] When the moving mechanism 60 moves the shuttle mechanism 18 in the left-right direction, it drives the stepping motor 50. Driven by the stepping motor 50, the grooved cam 51 rotates. The rotation of the grooved cam 51 causes the pin 70 to slide in the groove 54 of the grooved cam 51. Link members 68, 71, and 77 are driven in conjunction with the sliding of the pin 70. The arm 80 of the link member 77 swings around the shoulder bolt 65, and the square piece 81 slides forward and backward along the groove 85. The square piece 81 slides forward and backward along the groove 85, dissipating the force that would move the block member 83 forward and backward. Therefore, a force that moves the block member 83 in the left-right direction acts on the block member 83. In this way, the rotational drive of the stepping motor 50 is converted into a force that moves the block member 83 in the left-right direction. The shuttle shaft 37 is translated left and right together with the block member 83 due to the frictional force acting between the rolling bearings 56 and 57.

[0054] A ball plunger 91 abuts against the block member 83 (see FIG. 3). As shown in FIGS. 14 and 15, the ball plunger 91 has a cylinder 92 that extends in the front-to-rear direction. The rear of the cylinder 92 is fixed to the lower machine frame 11 by a nut 94 (see FIG. 2). A spring 97 and a ball 93 are housed, in that order from rear, inside a hole 96 recessed rearward from the front end of the cylinder 92. A part of the ball 93 protrudes from an opening 95 at the front end of the hole 96. The ball 93 is fitted into a groove 87 of the block member 83. The spring 97 urges the ball 93 rearward, causing the ball plunger 91 to abut against the groove 87.

[0055] As described above, the shuttle mechanism 18 is supported by the shuttle shaft 47 via the shuttle shaft 37. The axis of the shuttle shaft 37 extends in the left-right direction. The shuttle mechanism 18 is moved in the left-right direction of the shuttle shaft 37 by the moving mechanism 60 via the shuttle shaft 37. The transmission mechanism 21 includes a pulley 22 and a spline nut 34. The pulley 22 has a hole 26 formed in the cylinder 24 of the pulley 22. The spline nut 34 is entirely embedded in the hole 26. The inner circumferential surface of the spline nut 34, defined by the through-hole 35, has internal teeth 36 formed in a direction parallel to the left-right direction. The side surface of the shuttle shaft 37 has external teeth 38 formed in a direction parallel to the left-right direction. The external teeth 38 of the shuttle shaft 37 mesh with the internal teeth 36 of the spline nut 34. When the sewing machine motor 6 is driven, the pulley 22, spline nut 34, and shuttle shaft 37 rotate together about their axis. When the shuttle shaft 37 is moved in the left-right direction by the moving mechanism 60, the external teeth 38 are guided by the internal teeth 36 of the through-hole 35. Since the spline nut 34 is entirely embedded in the hole 26, the sewing machine 1 can be made smaller in the left-right direction while still comprising the transmission mechanism 21 and the moving mechanism 60.

[0056] The stepping motor 50 of the movement mechanism 60 has a built-in electromagnetic brake that operates when not energized. The electromagnetic brake prevents the rotation of the rotary shaft 50A of the stepping motor 50 around its axis when not energized. A grooved cam 51 is provided above the stepping motor 50. The rotary shaft 50A of the stepping motor 50 is fixed to the grooved cam 51. Therefore, when there is no need for the sewing machine 1 to move the shuttle mechanism 18 by the movement mechanism 60, the sewing machine 1 can easily prevent the shuttle mechanism 18 from moving in the left-right direction by not energizing the stepping motor 50. Furthermore, the sewing machine 1 can easily control the amount of left-right movement of the shuttle mechanism 18 by controlling the stepping motor 50.

[0057] The moving mechanism 60 includes a grooved cam 51. The grooved cam 51 is rotated by the driving of the stepping motor 50. The rotation of the grooved cam 51 causes a pin 70 to slide in a groove 54 of the grooved cam 51. Link members 68, 71, and 77 are driven in conjunction with the sliding of the pin 70. When there is no need to move the shuttle mechanism 18 by the moving mechanism 60, the rotating shaft 50A is less likely to rotate than when there is no grooved cam 51. Therefore, the sewing machine 1 can reduce the load on the stepping motor 50 when there is no need to move the shuttle mechanism 18 by the moving mechanism 60.

[0058] The arm 79 of the link member 77 is located above the link member 71. The eccentric pin 72 is inserted through a through hole 71B of the link member 71 and a through hole 79A of the arm 79, from below. The cylinder 74 of the eccentric pin 72 is inserted through the through hole 71B. The link member 71 fixes the cylinder 74. The cylinder 75 of the eccentric pin 72 is inserted through the through hole 79A. The arm 79 is provided to be swingable around the cylinder 75. Since the axis C2 of the cylinder 75 of the eccentric pin 72 is eccentric with respect to the axis C1 of the cylinder 74, an operator can adjust the position of the fulcrum around which the arm 79 of the link member 77 swings relative to the link member 77 by rotating the eccentric pin 72 with a tool or the like. Therefore, the sewing machine 1 can adjust the left-right movement of the shuttle mechanism 18 by the movement mechanism 60 with a simple configuration.

[0059] When the stepping motor 50 is driven, the arm 80 of the link member 77 swings around the shoulder bolt 65, and the square piece 81 slides in the front-to-rear direction while being guided by the groove 85. As the square piece 81 slides in the front-to-rear direction while being guided by the groove 85, the force that moves the block member 83 in the front-to-rear direction is released. Therefore, a force that moves the block member 83 in the left-to-right direction acts on the block member 83. In this way, the rotational drive of the stepping motor 50 is converted into a force that moves the block member 83 in the left-to-right direction. The shuttle shaft 37 moves in the left-to-right translation direction integrally with the block member 83 due to the frictional force acting between the rolling bearings 56 and 57. Therefore, the sewing machine 1 can move the shuttle shaft 37 in the left-to-right direction using the movement mechanism 60 with a simple configuration.

[0060] The rear portion of the cylinder 92 of the ball plunger 91 is fixed to the lower machine frame 11 by a nut 94. A ball 93 provided at the front end portion of the ball plunger 91 abuts against a groove 87 of the block member 83. The shuttle shaft 37 rotates about its axis when driven by the sewing machine motor 6. A force acts on the block member 83 to rotate about the axis of the shuttle shaft 37 due to frictional force acting between the shuttle shaft 37 and the rolling bearings 56, 57. In the sewing machine 1, the ball plunger 91 fixed to the lower machine frame 11 abuts against the groove 87 of the block member 83, so the block member 83 does not rotate relative to the shuttle shaft 37. Therefore, the sewing machine 1 can prevent the block member 83 from rotating relative to the shuttle shaft 37 with a simple configuration. In addition, because the groove 87 extends in the left-right direction, the ball plunger 91 does not interfere with the translational movement of the block member 83 in the left-right direction.

[0061] In the above embodiment, the left-right direction is an example of the axial direction of the present invention. The hole 26 is an example of the hole portion of the present invention. The sewing machine motor 6 is an example of the external power source of the present invention. The pulley 22 is an example of the rotating body of the present invention. The electromagnetic brake of the stepping motor 50 is an example of the brake mechanism of the present invention. The grooved cam 51 is an example of the cam of the present invention. The link member 71 is an example of the first link member of the present invention. The link member 77 is an example of the second link member of the present invention. The block member 83 is an example of the locking portion of the present invention and an example of the bearing portion of the present invention. The front-rear direction is an example of the cross direction of the present invention. The groove 85 is an example of the cross engaging portion of the present invention. The square piece 81 is an example of the cross engaged portion of the present invention. The groove 87 is an example of the axial engaging portion of the present invention. The lower machine frame 11 is an example of the machine frame of the present invention. The ball plunger 91 is an example of the axial engaged portion of the present invention.

[0062] The present invention can be modified in various ways from the above-described embodiment. The various modifications described below can be combined with each other as long as no contradictions arise. For example, the axes of the shuttle shafts 37, 47 need only intersect vertically, and are not limited to the left-right direction. In the above-described embodiment, the transmission mechanism 21 includes the pulley 22, but it is sufficient that it rotates around the axis of the shuttle shaft 37. For example, a gear or a cam may be provided instead of the pulley 22. It is sufficient that at least a portion of the spline nut 34 is embedded in the hole 26. The spline nut 34 may also be embedded in the hole 27.

[0063] The motor that drives the movement mechanism 60 may be, for example, a servo motor instead of the stepping motor 50. The stepping motor 50 does not need to be equipped with an electromagnetic brake. Instead of an electromagnetic brake, the stepping motor 50 may be, for example, a gripping unit that mechanically grips the rotating shaft 50A when the stepping motor 50 is not energized, thereby suppressing rotation of the rotating shaft 50A.

[0064] The movement mechanism 60 does not have to include the grooved cam 51. The movement mechanism 60 may transmit the drive of the stepping motor 50 using, for example, a gear or a cam. The movement mechanism 60 may convert the rotational drive of the stepping motor 50 into a force that moves the block member 83 in the left-right direction by meshing a pinion fixed to the rotation shaft 50A of the stepping motor 50 with a rack provided on the block member 83. The groove 54 of the grooved cam 51 does not have to be annular in bottom view, and may be formed, for example, in a C-shape, a straight line, or a combination of a straight line and a curve in bottom view. The groove 54 of the grooved cam 51 may be replaced by a through-hole that passes through the disk 52 in the up-down direction.

[0065] The movement mechanism 60 does not have to include the link members 68, 71, 77. The number of link members is not limited to that in the above embodiment. The positions of the pivot points of the link members 68, 71, 77 may be changed as appropriate. The movement mechanism 60 does not have to include the eccentric pin 72. The number of eccentric pins is not limited to that in the above embodiment. The link members 68, 71 may be connected by an eccentric pin.

[0066] In the above embodiment, the movement mechanism 60 applies a force to move the block member 83 in the left-right direction by combining the square piece 81 and the groove 85 of the block member 83. However, this is not limited to this. A recess that is recessed upward and extends in the front-to-rear direction may be formed in the arm 80 of the link member 77, and a protrusion that engages with the recess may be formed at the upper end of the block member 83. In this case, the movement mechanism 60 applies a force to move the block member 83 in the left-to-right direction by sliding the recess against the protrusion in the front-to-rear direction. The groove 85 is not limited to extending in the front-to-rear direction, as long as it extends in a direction that intersects the left-to-right direction in a plan view. The groove 85 may be formed, for example, as a curve in a plan view or a combination of straight and curved lines.

[0067] In the above embodiment, the movement mechanism 60 suppresses the force that rotates the block member 83 around an axis parallel to the left-right direction by combining the ball plunger 91 and the groove 87 of the block member 83. However, instead of the ball plunger 91, the movement mechanism 60 may include a cylinder whose axis extends in the front-rear direction and whose rear surface has a groove recessed forward and extending in the left-right direction. In this case, the movement mechanism 60 may be formed with a convex portion that engages with the groove of the cylinder and extends in the left-right direction. The groove 87 is not limited to extending in the front-rear direction, but may extend in a direction intersecting the left-right direction in a plan view. Instead of the groove 87, a hole recessed rearward may be formed in the front surface 86 of the block member 83. The ball plunger 91 may be provided to be movable in the left-right direction.

[0068] In the above embodiment, a gate-type sewing machine has been described as an example, but the present invention is not limited to a gate-type large sewing machine, and can be similarly applied to a small sewing machine. [Explanation of symbols]

[0069] 1 sewing machine 18. Hook mechanism 22 Pulley 34 Spline nut 37, 47 Hook shaft 50 stepping motor 51 Groove cam 60 Moving mechanism 71, 77 Link members 72 Eccentric pin 81 Square piece 83 Block member 91 Ball plunger

Claims

1. a hook mechanism that captures the upper thread that passes through the sewing needle as it moves up and down and entangles it with the lower thread; a hook shaft that extends in an axial direction intersecting the vertical direction and is rotatable about an axis parallel to the axial direction, and that supports the hook; external teeth formed on the shuttle shaft in a direction parallel to the axial direction; a moving mechanism that moves the shuttle in the axial direction via the shuttle shaft; a spline nut into which the shuttle shaft is inserted and which has internal teeth on its inner peripheral surface that mesh with the external teeth; a rotating body having a hole opening in the axial direction and adapted to transmit external power to rotate around the axis, The sewing machine is characterized in that at least a portion of the spline nut is embedded in the hole.

2. 2. The sewing machine according to claim 1, wherein the movement mechanism includes a motor and a brake mechanism that suppresses rotation of a rotary shaft of the motor when the motor is not energized.

3. The sewing machine according to claim 1 or 2, characterized in that the movement mechanism includes a motor and a cam that rotates when driven by the motor and has a second hole portion that opens in a second intersecting direction that intersects with the rotation axis of the motor.

4. The sewing machine according to any one of claims 1 to 3, characterized in that the movement mechanism comprises a motor, a first link member that swings when driven by the motor, a second link member that swings when the first link member swings, and an eccentric pin that connects the first link member and the second link member.

5. 5. The sewing machine according to claim 1, wherein the movement mechanism comprises a motor, a locking portion that locks onto the shuttle shaft, a cross-engagement portion that is formed on the locking portion and extends in a cross direction that intersects with the axial direction, and a cross-engaged portion that moves in the cross direction while being guided by the cross-engagement portion when driven by the motor, and that transmits the driving force of the motor to the locking portion in the axial direction.

6. the moving mechanism includes a bearing portion that supports the shuttle shaft rotatably around the axis, and an axial center engaging portion that extends in the axial direction of the bearing portion, 6. The sewing machine according to claim 1, further comprising an axially engaged portion, one end of which is fixed to a machine frame of the sewing machine and extends toward the axially engaging portion, and the other end of which is engaged with the axially engaging portion.

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