JP7768014B2 - sewing machine - Google Patents

Description

The present invention relates to a sewing machine.

Sewing machines are known that move 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 eccentric pin mechanism converts the rotational drive of the stepping motor into forward and backward drive. The eccentric pin mechanism engages with a sleeve. The sleeve pivots on 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.

Japanese Patent Application Publication No. 11-226285

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 equipped 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. As a result, the rotary hook shaft becomes longer in the axial direction, which could result in the sewing machine becoming larger.

The 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.

One aspect of the present invention relates to a sewing machine comprising: a shuttle mechanism that captures the upper thread inserted into a sewing needle that moves up and down and intertwines it with the bobbin thread; a shuttle shaft that supports the shuttle, extending in an axial direction intersecting the vertical direction and rotatable about an axis parallel to the axial direction; external teeth formed on the shuttle shaft and 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 having internal teeth on its inner circumferential surface that mesh with the external teeth; and a rotor that has a hole that opens in the axial direction and transmits external power to rotate about the axis, wherein at least a portion of the spline nut is embedded in the hole.

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. Furthermore, 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 rotation hole. Therefore, the sewing machine can be made smaller in size in the axial direction while still being equipped with a mechanism that rotates the shuttle shaft about an axis parallel to the axial direction and a moving mechanism that moves the shuttle shaft in the axial direction.

The movement 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 a 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 movement mechanism. Therefore, when there is no need to move the shuttle mechanism by the movement mechanism, the sewing machine can easily suppress axial movement of the shuttle mechanism by not energizing the motor.

The movement 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 movement mechanism includes a cam, when there is no need to move the shuttle mechanism by the movement mechanism, the motor's rotation shaft rotates less easily than if there was no cam. Therefore, the sewing machine can reduce the load on the motor's rotation shaft when there is no need to move the shuttle mechanism by the movement mechanism.

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.

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 intersecting 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 transmits the driving force of the motor in the axial direction to the locking portion. In the sewing machine, the cross-engagement portion moves while being guided by the cross-engaged portion, thereby converting the rotational motion of the motor's rotating shaft into the axial direction. 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.

The movement mechanism may include a bearing portion that supports the shuttle shaft rotatably around the axis, an axis engaging portion that extends in the axis direction of the bearing portion, and an axis engaged portion that is fixed to the sewing machine frame, extends toward the axis engaging portion, and engages with the axis engaging portion at its other end. The bearing portion may rotate slightly around an axis parallel to the axis 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 sewing machine frame, prevents the bearing portion from rotating around an axis parallel to the axis direction. Therefore, the sewing machine can prevent the bearing portion from rotating around an axis parallel to the axis direction with a simple configuration.

FIG. 2 is a perspective view of the sewing machine 1 on the table 100. FIG. FIG. 2 is a perspective view of the shuttle mechanism 18, the shuttle support portion 20, and the moving mechanism 60. FIG. 2 is a plan view of the shuttle mechanism 18, the shuttle support portion 20, and the moving mechanism 60. 5 is a cross-sectional view taken along line AA of FIG. 4, viewed from the direction of the arrows. FIG. 2 is an exploded perspective view of the shuttle mechanism 18, the shuttle support portion 20, and the block member 83. FIG. FIG. FIG. FIG. FIG. FIG. FIG. FIG. 15 is a cross-sectional view taken along line BB in FIG. 14, viewed from the direction of the arrows.

One 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 back, and top and bottom.

Sewing machine 1 is a gate-type sewing machine capable of sewing on a sewing object. As shown in Figure 1, 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 housing 10.

The bed section 2 has a base 121, a pair of front and rear rails, and a frame 122. The base 121 is approximately rectangular. The upper surface of the base 121 forms a flat holding surface 121A extending horizontally. A holding plate 123 extending forward along the holding surface 121A is provided at the front end of the base 121. A bellows 121R extending in the front-rear direction is provided near the right end of the holding surface 121A. A bellows 121L extending 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 the 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. The bed section 2 has a lower rail (not shown) and the shuttle container 10 (described below) located below the base 121. The lower rail extends in the left-right direction and supports the shuttle container 10 so that it can move left-right.

The pair of pillars 3, 4 each have a roughly rectangular pillar shape. Pillar 3 extends upward from the right end of the base 121 of the bed 2, a position 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 the left end of the base 121 of the bed 2, a position 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.

The beam 5 is installed between each of 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 each 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. The bellows 152 is installed at 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 (described below). The bellows 152 covers the front side of the upper rail.

The needle bar mechanism 106 is located on the front side of the beam 5. The needle bar mechanism 106 is equipped with a needle bar (not shown). The needle bar extends in the vertical direction and can be fitted with a sewing needle. The needle bar is movable in the vertical direction. The needle bar mechanism 106 is movable left and right along the front end of the beam 5, along an upper rail within the beam 5. The bellows 152 expands and contracts as the needle bar mechanism 106 moves back and forth left and right along the upper rail.

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 has connecting portions 211 and 212. The lower left end of connecting portion 211 is positioned on the front-to-rear rail on the left side of the bed portion 2. The lower right end of connecting portion 212 is positioned 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 vertically relative to the lower frame 182 using air cylinders 183 and 184 as drive sources.

As shown in Figure 2, the shuttle housing 10 includes a lower machine frame 11, a sewing machine motor 6, a shuttle support 20, a shuttle mechanism 18, and a movement mechanism 60. The lower machine frame 11 is box-shaped and houses the shuttle support 20, the shuttle mechanism 18, and the movement mechanism 60.

The sewing machine motor 6 is mounted at the lower end of the shuttle housing 10. The rotation shaft of the sewing machine motor 6 extends in the left-right direction. A connecting pulley 12 is mounted to the right of the sewing machine motor 6. The rotation shaft of the sewing machine motor 6 is fixed to the connecting pulley 12.

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

The structure of the shuttle support section 20 will be described with reference to Figures 3 to 7. The left end of the shuttle support section 20 supports the shuttle mechanism 18. The shuttle support section 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.

Pulley 22 comprises cylinders 23, 24, and 25. The axes of cylinders 23, 24, and 25 extend parallel to the left-right direction. The axes of cylinders 23, 24, and 25 are aligned. The diameter of the bottom surface of cylinder 23 is larger than the diameter of the bottom surface of cylinder 24. The diameter of the bottom surface of cylinder 24 is larger than the diameter of the bottom surface of cylinder 25. Cylinder 23 is connected to the right end of cylinder 25. Cylinder 24 is connected to the right end of cylinder 23.

External teeth 28 are formed on the side of the 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 the external teeth 28, as shown in Figure 2. The belt is driven by the rotation of the pulley 14, and the pulley 22 rotates around the axis of the cylinders 23, 24, and 25.

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.

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.

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 penetrates 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 penetrates the lower machine frame 11 in the left-right direction. The support members 30, 32 can rotate using the lower machine frame 11 as a sliding bearing.

A through-hole 31 is formed in the center of the bottom surface of the shaft support member 30, penetrating the shaft support 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 shaft support member 32, penetrating the shaft support 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 shaft support members 30 and 32 of the transmission mechanism 21 rotate together around the axis.

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

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 rotates due to the drive of the sewing machine motor 6, the shuttle shaft 37 rotates integrally with the transmission mechanism 21 around its axis. The shuttle shaft 37 is able to translate left and right, with its external teeth 38 guided by the internal teeth 36 of the through-hole 35.

As shown in Figure 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. Clamp 40 is connected to the right end of clamp 41. The left end of the shuttle shaft 37 is fixed by clamp 40 of the connecting clamp 39.

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

The shuttle shaft 47 passes 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 into 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 passes 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.

The right end of the shuttle mechanism 18 is connected to shaft 19. Shaft 19 extends left and right. 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 the needle plate 13, shuttle mechanism 18 captures the loop of needle thread inserted into the sewing needle. This allows the sewing machine 1 to stitch the fabric placed on the needle plate 13.

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, and 77, an eccentric pin 72, a square piece 81, and a block member 83.

The stepping motor 50 is provided behind the shuttle mechanism 18 (see Figure 4). The stepping motor 50 has a built-in electromagnetic brake that operates when not energized. As shown in Figure 9, the rotating shaft 50A of the stepping motor 50 extends vertically. 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.

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 is formed in the bottom surface of the disk 52, recessed upward. A cylinder 55 protrudes downward from the center of a central portion 53 of the disk 52, which is defined inside the groove 54. 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 is formed in the bottom surface of the cylinder 55, recessed upward. The rotating shaft 50A of the 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.

As shown in Figures 4 and 9, the fulcrum pin 61 is located 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 located to the left and in front of the fulcrum pin 61 and behind the shuttle support portion 20. More specifically, the shoulder bolt 65 is located behind the block member 83 through which the shuttle shaft 37 passes.

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 arranged 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 secures the lower end of the pin 70.

The link member 71 is a rod-shaped member extending forward and to the right from the grooved cam 51. A through-hole 71A that penetrates vertically is formed at the left end of the link member 71 (the grooved cam 51 side) in the left-right direction. A pin 70 is inserted into the through-hole 71A above the link member 68. The link member 71 is arranged 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 vertically is formed at the right end of the link member 71. An eccentric pin 72 is inserted into the through-hole 71B.

As shown in Figures 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.

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 on the upper surface of cylinder 75. Groove 76 can fit with a tool such as a screwdriver.

As shown in Figures 4, 9, and 10, the link member 77 is a rod-shaped member bent into an L-shape in 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 arranged to be swingable around the shoulder bolt 65.

The arm 79 is rod-shaped and extends from the base 78 toward the eccentric pin 72. A through-hole 79A that penetrates vertically is formed at the end of the arm 79 on the eccentric pin 72 side. The eccentric pin 72 passes through the through-hole 71B of the link member 71 and the through-hole 79A of the arm 79, starting from the bottom. The cylinder 74 of the eccentric pin 72 is inserted through the through-hole 71B. The link member 71 secures the cylinder 74. The cylinder 75 of the eccentric pin 72 is inserted through the through-hole 79A. The arm 79 is pivotable 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, when an operator rotates the eccentric pin 72 with a tool or the like, the distance from the through-hole 71A of the link member 71 to the through-hole 79A of the arm 79 changes.

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

The square piece 81 is rectangular. It is located below the end of the arm 80 that faces the block member 83. A downwardly recessed screw hole 81A is formed on the top surface of the square piece 81. The screw 82 is inserted from above through the through hole 80A and washer 80B in the arm 80 and is screwed into the screw hole 81A in the square piece 81.

As shown in Figures 6 and 8, the block member 83 is 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-to-rear direction. The groove 85 is formed over the entire area of the block member 83 in the front-to-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-to-rear direction.

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 from the front surface 86 in a side view 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 left-right area of the block member 83.

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

As shown in Figure 5, the shuttle shaft 37 passes 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. Due to the frictional force acting between the shuttle shaft 37 and the rolling bearings 56, 57, the shuttle shaft 37 can 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.

When the movement mechanism 60 moves the shuttle mechanism 18 left and right, 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 along 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. As the square piece 81 slides forward and backward along the groove 85, the force moving the block member 83 forward and backward is released. Therefore, a force moving the block member 83 left and right acts on it. In this way, the rotational drive of the stepping motor 50 is converted into a force moving the block member 83 left and right. 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.

A ball plunger 91 abuts against the block member 83 (see Figure 3). As shown in Figures 14 and 15, the ball plunger 91 has a cylinder 92 extending 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 Figure 2). A spring 97 and a ball 93 are housed inside a hole 96 recessed rearward from the front end of the cylinder 92, in that order from rear to rear. A portion 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 in the block member 83. The spring 97 urges the ball 93 rearward, causing the ball plunger 91 to abut against the groove 87.

As described above, the shuttle mechanism 18 is supported on 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 left-right about 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 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 driven by the sewing machine motor 6, the pulley 22, spline nut 34, and shuttle shaft 37 rotate together about their axis. When the shuttle shaft 37 is moved left and right by the movement mechanism 60, the external teeth 38 are guided by the internal teeth 36 of the through-hole 35. Because the spline nut 34 is entirely embedded in the hole 26, the sewing machine 1 can be made smaller left and right while still being equipped with the transmission mechanism 21 and the movement mechanism 60.

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 the sewing machine 1 does not need to move the shuttle mechanism 18 using the movement mechanism 60, it can easily prevent the shuttle mechanism 18 from moving left and right by not energizing the stepping motor 50. Furthermore, the sewing machine 1 can easily control the amount of left and right movement of the shuttle mechanism 18 by controlling the stepping motor 50.

The movement mechanism 60 includes a grooved cam 51. The grooved cam 51 rotates when driven by the stepping motor 50. 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. When there is no need to move the shuttle mechanism 18 using the movement mechanism 60, the rotating shaft 50A rotates more difficultly than if 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 using the movement mechanism 60.

The arm 79 of the link member 77 is located above the link member 71. The eccentric pin 72 is inserted, starting from the bottom, through the through-hole 71B of the link member 71 and the through-hole 79A of the arm 79. The cylinder 74 of the eccentric pin 72 is inserted through the through-hole 71B. The link member 71 secures the cylinder 74. The cylinder 75 of the eccentric pin 72 is inserted through the through-hole 79A. The arm 79 is pivotable around the cylinder 75. Because 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 pivots relative to the link member 77 by rotating the eccentric pin 72 with a tool or the like. Therefore, the sewing machine 1 allows the left-right movement of the shuttle mechanism 18 by the movement mechanism 60 to be adjusted with a simple configuration.

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 back and forth along the groove 85. As the square piece 81 slides back and forth along the groove 85, the force that moves the block member 83 back and forth is released. Therefore, a force that moves the block member 83 left and right 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 left and right. The shuttle shaft 37 moves left and right together with the block member 83 in translation due to the frictional force acting between the rolling bearings 56 and 57. Therefore, the sewing machine 1 can move the shuttle shaft 37 left and right using the movement mechanism 60 with a simple configuration.

The rear of the cylinder 92 of the ball plunger 91 is fixed to the lower machine frame 11 with a nut 94. The ball 93 provided at the front end of the ball plunger 91 abuts against a groove 87 in 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 friction acting between the shuttle shaft 37 and the rolling bearings 56 and 57. In the sewing machine 1, the ball plunger 91 fixed to the lower machine frame 11 abuts against the groove 87 in 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. Furthermore, because the groove 87 extends in the left-right direction, the ball plunger 91 does not interfere with the left-right translational movement of the block member 83.

In the above embodiment, the left-right direction is an example of the axial direction of the present invention. Hole 26 is an example of the hole portion of the present invention. Sewing machine motor 6 is an example of the external power source of the present invention. Pulley 22 is an example of the rotating body of the present invention. The electromagnetic brake of stepping motor 50 is an example of the brake mechanism of the present invention. Groove cam 51 is an example of the cam of the present invention. Link member 71 is an example of the first link member of the present invention. Link member 77 is an example of the second link member of the present invention. 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-to-rear direction is an example of the cross direction of the present invention. Groove 85 is an example of the cross engaging portion of the present invention. Square piece 81 is an example of the cross engaged portion of the present invention. Groove 87 is an example of the axial engaging portion of the present invention. Lower machine frame 11 is an example of the machine frame of the present invention. Ball plunger 91 is an example of the axial engaged portion of the present invention.

The present invention can be modified in various ways from the above 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 in the vertical direction, and are not limited to the horizontal direction. In the above embodiment, the transmission mechanism 21 includes a pulley 22, but it need only be configured to rotate around the axis of the shuttle shaft 37; for example, a gear or cam may be provided instead of the pulley 22. The spline nut 34 may be at least partially embedded in the hole 26. The spline nut 34 may also be embedded in the hole 27.

The motor that drives the movement mechanism 60 may not be a stepping motor 50, but may be, for example, a servo motor. 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.

The movement mechanism 60 does not have to include a 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, as 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 vertical direction.

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

In the above embodiment, the movement mechanism 60 applies a force to move the block member 83 left and right by combining the square piece 81 with 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 left and right by sliding the recess against the protrusion in the front-to-rear direction. The groove 85 does not have to extend in the front-to-rear direction, as long as it extends in a direction that intersects the left and right directions 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.

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 be provided with a cylinder whose axis extends in the front-to-rear direction and whose rear surface has a groove that is recessed forward and extends in the left-to-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-to-right direction. The groove 87 is not limited to extending in the front-to-rear direction, but may extend in a direction that intersects the left-to-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-to-right direction.

In the above embodiment, a gate-type sewing machine was used as an example, but the invention is not limited to large gate-type sewing machines and can be applied to small sewing machines as well.

REFERENCE SIGNS LIST 1 sewing machine 18 shuttle mechanism 22 pulley 34 spline nuts 37, 47 shuttle shaft 50 stepping motor 51 grooved cam 60 movement mechanism 71, 77 link member 72 eccentric pin 81 square piece 83 block member 91 ball plunger

Claims (6)

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. The sewing machine of claim 1, characterized in that the movement mechanism includes a motor and a brake mechanism that suppresses rotation of the motor's rotation shaft when the motor is not energized. The sewing machine of 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 that opens in a second intersecting direction that intersects with the rotation axis of the motor. A 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 to the second link member. A sewing machine according to any one of claims 1 to 4, characterized in that the movement mechanism comprises a motor, a locking portion that locks to the shuttle shaft, a cross-engagement portion formed on the locking portion and extending in a direction intersecting 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 in the axial direction to the locking portion. 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.