Sewing machine

Abstract

The invention provides a sewing machine, which can adjust the timing of changing the acting force which is linked with a motor of the sewing machine and is applied to a presser foot arranged at the lower end of a pressing rod according to a sewed object through simpler operation than in the prior art. The sewing machine is provided with a needle plate, feed teeth, a pressure lever (8), a pressure lever hoop (82), an adjusting part (65), a pressing spring (81), a limiting part (67) and a changing component (70). The changing member (70) has a first member (71) and a second member (72), and changes the position of the restricting portion (67) in the vertical direction in accordance with the distance between the first member (71) and the second member (72). In a first condition in which the upper end of the feed tooth is positioned above the upper end of the needle plate and the adjustment part (65) is separated from the restriction part (67), the biasing force of the pressing spring (81) is transmitted to the pressure lever (8). In a second condition in which the upper end of the feed tooth is positioned below the upper end of the needle plate and the adjustment section (65) is in contact with the restriction section (67), the biasing force of the pressing spring (81) is not transmitted to the pressure lever (8).

Description

Technical Field

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

[0002] The presser foot device of an existing sewing machine has a connecting member, a moving member and an elastic member (for example, refer to Patent Document 1). The connecting member is connected to the main shaft of the sewing machine and swings. The moving member moves in the up and down direction as the connecting member swings. The elastic member is arranged between the moving member and the pressure rod, and the elastic force applied to the pressure rod is changed by the movement of the moving member. In the presser foot device, when the feed tooth rises from the needle plate, the moving member is moved to increase the force of the elastic member compared to when the feed tooth is located on the lower surface of the needle plate, thereby interlocking with the main shaft of the sewing machine to change the force applied to the presser foot provided at the lower end of the pressure rod. In order to absorb the changes corresponding to the thickness and hardness of the sewing object, the user can adjust the initial setting of the sewing machine.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-187288 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the existing presser foot device of a sewing machine, the structure for changing the pressing force applied by the presser foot to the workpiece is complex, and the adjustment operation for linking with the sewing machine motor to adjust the timing of the force applied to the presser foot installed at the lower end of the presser bar to correspond to the workpiece is complicated.

[0008] The object of the present invention is to provide a sewing machine which can adjust the timing of the change of the force applied to the presser foot installed at the lower end of the presser bar in accordance with the sewing object by simpler operation than before in conjunction with the sewing machine motor.

[0009] Means for solving problems

[0010] A sewing machine according to one embodiment of the present invention comprises: a sewing machine motor; a needle bar capable of mounting a machine needle at the lower end and moving in the up-and-down direction according to the driving of the sewing machine motor; a needle plate formed with a needle hole for the machine needle to pass through; a feed tooth protruding from or retracting into an opening formed in the needle plate according to the driving of the sewing machine motor and conveying the sewn material placed on the needle plate; a pressure rod capable of mounting a presser foot at the lower end and moving in the up-and-down direction synchronously with the driving of the feed tooth; a pressure rod clamp fixed to the pressure rod; an adjustment part capable of moving in the up-and-down direction; a pressing spring capable of applying force to the pressure rod downward via the adjustment part and the pressure rod clamp; and a limiting part limiting the pressure spring from pressing the pressure rod downward when contacting with the adjustment part. The rod transmits the force; and a change member, which has a first member and a second member supported so as to be movable relative to the first member, and changes the position of the limiting portion in the up-down direction according to the distance between the first member and the second member. In the first condition where the upper end of the feed tooth, i.e., the upper end of the tooth, is located above the upper end of the needle plate, i.e., the upper end of the plate, and the adjustment portion is separated from the limiting portion, the adjustment portion and the pressure rod clamp abut against each other, and the force of the pressing spring is transmitted to the pressure rod. In the second condition where the upper end of the tooth is located below the upper end of the plate and the adjustment portion abuts against the limiting portion, the adjustment portion and the pressure rod clamp are separated in the up-down direction, and the force of the pressing spring is not transmitted to the pressure rod. The sewing machine of this scheme enables the user to adjust the timing of switching the force of the pressing spring to be transmitted to the pressure rod or not to be transmitted to the pressure rod by a relatively simple operation such as changing the distance between the first member and the second member. Therefore, the contribution of the sewing machine is that the operation of adjusting the timing of changing the force applied to the presser foot mounted on the lower end of the presser bar in conjunction with the sewing machine motor according to the workpiece is simpler than before. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a perspective view of the sewing machine 1 .

[0012] Figure 2 (A) is a stereoscopic view of the pressure rod 8, the pressure rod clamp 82, the adjustment mechanism 68 and the change component 70 under the first condition F1 in which the first wall 61 of the adjustment part 65 abuts against the limiting part 67 in the up-down direction, and (B) is a stereoscopic view of the pressure rod 8, the pressure rod clamp 82, the adjustment mechanism 68 and the change component 70 under the second condition F2 in which the first wall 61 of the adjustment part 65 and the limiting part 67 are separated in the up-down direction.

[0013] Figure 3Figure (A) is a right view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the first condition F1, and figure (B) is a right view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the second condition F2.

[0014] Figure 4 Figure (A) is a rear view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the first condition F1, and figure (B) is a rear view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the second condition F2.

[0015] Figure 5 Figure (A) is a perspective view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the first condition F1, and figure (B) is a perspective view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 under the second condition F2.

[0016] Figure 6 is a front view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68 with the limiting part 67 disposed at the reference position, and the modification member 70.

[0017] Figure 7 is a front view of the adjustment mechanism 68 and the modification member 70 in which the limiting part 67 is moved to a position 4 mm above the reference position.

[0018] Figure 8 is a front view of the pressure bar 8, the pressure bar hoop 82, the adjustment mechanism 68, and the modification member 70 in a state where the convex part 93 of the rod 90 abuts against the pressure bar hoop 82.

[0019] Figure 9 Figure (A) is a sectional view of the modification member 70 under the first condition F1, and figure (B) is a sectional view of the modification member 70 under the second condition F2.

[0020] Figure 10 is an explanatory diagram of the vertical position of the needle bar 31, the vertical position of the feed teeth 19, the vertical position of the pressure bar hoop 82, the pressing force applied by the presser foot 5 to the workpiece C, and the vertical interval between the limiting part 67 and the first wall 61 of the adjustment part 65 corresponding to the rotation angle of the sewing machine motor 2. Detailed Embodiments

[0021] The embodiments of the present invention will be described with reference to the accompanying drawings. Refer to Figures 1 to 9The following description (B) explains the physical structure of the sewing machine 1. The sewing machine 1 of the present embodiment is a sewing machine having the following function: by mechanically changing the pressing force applied to the presser foot 5 at a prescribed timing during one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction, curve sewing is made easier. The sewing machine 1 has a structure capable of easily switching the pressing force applied to the presser foot 5 between a pressing force suitable for curve sewing and a pressing force suitable for normal (straight) sewing. Figure 1 The vertical direction, lower right, upper left, lower left, and upper right directions are respectively the vertical direction, right side, left side, front side, and rear side of the sewing machine 1 on which the presser foot device 9 is mounted. The extending direction of the column 12 is the vertical direction of the sewing machine 1. The base 11 and the arm 13 extend from the column 12 in the left direction.

[0022] As Figure 1 shown, the sewing machine 1 has a base 11, a column 12, an arm 13, and a head 14. The base 11 is the base of the sewing machine 1 extending in the left-right direction and has a needle plate 3. The needle plate 3 is provided on the upper surface of the base 11. The needle plate 3 is a horizontally extending plate-shaped member and is formed with a needle insertion hole 25 for inserting a sewing needle 35 (described later) and an opening 26 extending in the front-rear direction. The base 11 has a feed tooth 19, Figure 6 as shown, a bobbin mechanism 20, and a feed mechanism 23 below the needle plate 3. The feed tooth 19 projects or retracts from the opening 26 formed in the needle plate 3 to convey the workpiece C placed on the needle plate 3. The feed mechanism 23 drives the feed tooth 19 according to the drive of a sewing motor 2 (described later) to convey the workpiece C backward or forward. As Figure 6 shown, the bobbin mechanism 20 has a lower shaft 21 and a horizontal bobbin 22. The horizontal bobbin 22 rotates according to the rotation of the lower shaft 21 and tangles the upper thread (not shown) and the bobbin thread (not shown) below the needle plate 3.

[0023] As Figure 1 shown, the column 12 is erected upward from the right end portion of the base 11. A sewing motor 2 is provided inside the upper part of the column 12. An LCD 15 is provided on the front surface of the column 12. A switch 16 is provided below the LCD 15. A pulley 28 is provided on the right surface of the column 12.

[0024] The arm 13 is opposite to the machine base 11 and extends to the left from the upper end of the column 12. The head 14 is a portion connected to the left front end of the arm 13. The head 14 is provided with a thread take-up lever 36, a needle bar 31, a needle bar mechanism (not shown), a pressure rod 8, and an adjustment mechanism 68. The thread take-up lever 36 lifts the surface thread entangled between the shuttle and the bottom line according to the drive of the sewing machine motor 2. The needle bar 31 can be equipped with a needle 35 at the lower end and move in the up-down direction according to the drive of the sewing machine motor 2. A needle bar clamp is fixed to the lower end of the needle bar 31. The needle bar clamp fixes the needle 35 in a detachable manner. The needle bar mechanism moves the needle bar 31 in the up-down direction according to the drive of the sewing machine motor 2. The needle bar 31 also moves in the up-down direction when the pulley 28 is rotated by the user.

[0025] The pressure rod 8 extends in the vertical direction behind the needle bar 31, and moves in the vertical direction synchronously with the driving of the sewing machine motor 2, more specifically, the feed tooth 19. Figure 2 As shown in (A), the pressure rod 8 is provided with a pressing spring 81, a pressure rod clamp 82 and a rod 90. The pressing spring 81 is a coil spring externally inserted into the pressure rod 8. The pressure rod clamp 82 is fixed to the pressure rod 8 and contacts the lower end of the pressing spring 81 to limit the lower end position of the pressing spring 81. The pressing spring 81 can apply force to the pressure rod 8 downward via the adjustment part 65 and the pressure rod clamp 82. Figure 3 As shown in A, the pressure rod clamp 82 has a receiving portion 85, which receives the lower end portion of the adjustment spring 84 and is recessed downward by the first length L1. The acting force of the adjustment spring 84 is smaller than that of the pressing spring 81. The adjustment spring 84 in this example is a coil spring. The adjustment spring 84 is received in the receiving portion 85 in a state of being inserted into the pressure rod 8. In the up and down directions, the lower end of the adjustment spring 84 is defined by the bottom surface of the receiving portion 85. The upper end of the adjustment spring 84 is defined by the adjustment portion 65 described later, which is arranged above the pressure rod clamp 82.

[0026] like Figure 2 As shown in A, the rod 90 is manually switched to change the position of the pressure rod 8 in the up and down directions. The rod 90 includes a shaft 91, convex parts 92, 93 and an operating part 94. The shaft 91 is provided inside the head 14. The convex parts 92, 93 are parts protruding from the vicinity of the shaft 91 to a side away from the shaft 91. The operating part 94 is the part farthest from the shaft 91. By operating the operating part 94 with an operating body such as a finger, the user can rotate the rod 90 in a clockwise direction or a counterclockwise direction when viewed from the front with the shaft 91 as the center, and switch the pressure rod 8 between the raised position and the lowered position. Figure 2 (A) to Figure 7 The operation portion 94 is shown in the state where it is arranged below the shaft portion 91 and the pressure rod 8 is in the lowered position. Figure 6When rotating in the counterclockwise direction when viewed from the front, and when the operation portion 94 is disposed in the upper right with respect to the shaft portion 91, the convex portion 93 of the lever 90 abuts against the lower surface 83 of the presser bar clamp 82, causing the presser bar 8 to move to the raised position. Figure 8 It shows a state where the operation portion 94 is disposed in the upper right with respect to the shaft portion 91 and the presser bar 8 is in the raised position. When the user has the presser bar 8 disposed in the raised position, the user performs the operation of disposing or retrieving the workpiece C to be sewn.

[0027] As Figure 3 As shown in A, a hole 86 penetrating in the left - right direction is formed at the lower end portion of the presser bar 8. The presser foot device 9 is detachably attached to the lower end portion of the presser bar 8 by a screw 41 passing through the hole 86. The presser foot device 9 supports the presser foot 5 so as to be swingable about an axis 53 extending in the left - right direction. The presser foot 5 is a rectangular plate - shaped that is long in the front - rear direction when viewed from above. The front end portion and the rear end portion of the presser foot 5 are bent upward respectively. As Figure 1 shown, a notch portion 59 is formed at the front portion of the presser foot 5. The presser foot device 9 that supports the presser foot 5 is attached to the lower end of the presser bar 8. When the sewing machine 1 is driven, the sewing needle 35 is inserted through the rear end portion of the notch portion 59. When the presser bar 8 is in the lowered position, the presser foot 5 contacts the workpiece C placed on the needle plate 3 and presses the workpiece C downward. The sewing machine 1 of this example can switch whether to change the pressing force transmitted to the presser foot 5 during one reciprocation of the needle bar 31 of the sewing machine 1 in the up - down direction by operating a change member 70 of an adjustment mechanism 68 described later.

[0028] As Figure 2 (A) and Figure 5As shown in (A), the adjustment mechanism 68 includes an adjustment portion 65, a restriction portion 67, and a change member 70. The adjustment portion 65 is movable in the vertical direction and defines the lower end of the pressing spring 81 and the upper end of the adjustment spring 84. The adjustment portion 65 is formed, for example, by bending a metal plate. The adjustment portion 65 is a plate-shaped member formed with a first insertion portion 42 through which a change shaft 66 of the change member 70 described later is inserted and a second insertion portion 43 through which the pressure lever 8 is inserted. The adjustment portion 65 includes a first wall 61, a second wall 62, a third wall 63, and a fourth wall 64. The first wall 61 is a plate-shaped member that horizontally extends to the left of the pressure lever 8. The first insertion portion 42 is formed in the first wall 61. The first insertion portion 42 is a hole that penetrates the first wall 61 in the vertical direction and is circular in plan view. The first wall 61 defines the lower end of the movement range of the adjustment portion 65 by abutting against the restriction portion 67. The second wall 62 is provided at a position lower than the first wall 61 and is a plate-shaped member that horizontally extends to the right of the first wall 61. The second insertion portion 43 is formed in the second wall 62. The second insertion portion 43 is a hole that penetrates the second wall 62 in the vertical direction and is circular in plan view, through which the pressure lever 8 is inserted. The third wall 63 connects the first wall 61 and the second wall 62 in the vertical direction. The third wall 63 is a plate-shaped member that extends in the vertical direction to the left of the pressure lever 8 and connects the right end portion of the first wall 61 and the second wall 62. The first wall 61, the second wall 62, and the third wall 63 of the adjustment portion 65 have a crank shape that is Z-shaped in front view.

[0029] The fourth wall 64 is connected to the third wall 63 and extends parallel to the pressure lever 8. The fourth wall 64 extends rightward from the rear end portion of the third wall 63. In the left-right direction, the left end portion of the fourth wall 64 is located to the left of the pressure lever 8, and the right end portion of the fourth wall 64 is located to the right of the pressure lever 8. As shown in Figure 2 (A) and Figure 4As shown in (A), the fourth wall 64 has a pair of upper and lower pins 78 protruding rearward. A plate-like portion 100 extending parallel to the fourth wall 64 is provided behind the fourth wall 64. The plate-like portion 100 extends in the vertical and horizontal directions over a larger range than the fourth wall 64. Slits 101 and 102 extending in the vertical direction and penetrating in the front-rear direction are formed in the plate-like portion 100. The slit 101 is formed behind the pressure lever 8. The pair of pins 78 are inserted through the slit 101 of the plate-like portion 100. The slit 101 guides the vertical movement of the adjustment portion 65. The slit 102 is formed behind the change axis 66 and at a position above the slit 101. The plate-like portion 100 also includes insertion portions 103 and 104 in which holes (not shown) penetrating in the vertical direction are formed. The insertion portions 103 and 104 are portions formed by bending the plate-like portion 100 forward, and the change axis 66 is inserted through the holes. A restricting member 75 is fixed to the upper left portion of the plate-like portion 100 by a screw 77. The restricting member 75 is a leaf spring extending in the left-right direction. The right end portion of the restricting member 75 has a convex portion 76 protruding forward. The convex portion 76 is a portion where the leaf spring is bent into a V shape when viewed from above.

[0030] As Figure 2 shown in A, when the restricting portion 67 abuts against the adjustment portion 65, it restricts the transmission of the acting force of the pressing spring 81 to the pressure lever 8. The restricting portion 67 is a rectangular parallelepiped fixed to the lower end portion of the change axis 66. The restricting portion 67 is disposed below the first wall 61 of the adjustment portion 65 and abuts against the lower surface of the first wall 61 in a manner that allows contact and separation, thereby restricting the movement range of the adjustment portion 65.

[0031] As Figure 2 shown in A to Figure 5 B, the change member 70 includes a change axis 66, a first member 71, a second member 72, an abutted portion 73, a first stopper 45, a second stopper 46, and a cover 74. The change axis 66 is a shaft-like member extending parallel to the pressure lever 8 to the left of the pressure lever 8, and supports the adjustment portion 65 so as to be movable in the vertical direction. The change axis 66 is inserted through the first insertion portion 42 of the first wall 61. The change axis 66 includes an abutting portion 69 and a shaft 49. As Figure 5 shown in A, the abutting portion 69 is a rod-like member extending perpendicular to the change axis 66 provided at the upper end portion of the change axis 66. The abutting portion 69 extends forward from the change axis 66. The shaft 49 is a rod-like member extending perpendicular to the change axis 66 provided below the abutting portion 69. As Figure 4 shown in A, the shaft 49 extends rearward from the change axis 66 and is inserted through the slit 102. The slit 102 guides the vertical movement of the change axis 66 and restricts the rotation of the change axis 66 about an axis extending in the vertical direction.

[0032] The first member 71 has a first surface 51 that extends in a horizontal direction orthogonal to the vertical direction. The first surface 51 is exposed to the outside of the cover 17. The vertical position of the first surface 51 in the present embodiment is substantially the same as the vertical position of the upper surface of the cover 17 of the sewing machine 1. The portion of the upper surface of the cover 17 that is adjacent to the first surface 51 in the left-right direction, which is the longitudinal direction of the arm 13, extends horizontally in parallel with the first surface 51. The change axis 66 extends in parallel with the presser bar 8 and is connected to the restricting portion 67. The first member 71 is formed with a hole 56 through which the change axis 66 is inserted, and the hole 56 penetrates in the vertical direction. The first member 71 is a disk-shaped portion that is externally inserted into the change axis 66 when viewed from above. The first member 71 includes a cylindrical portion 87, a flange 88, a dial 89, and a cylindrical portion 95. A recess 80 (see Figure 3 of (B)) that extends in the vertical direction and is recessed toward the change axis 66 is formed on the outer periphery of the cylindrical portion 87. The flange 88 projects horizontally from the lower end of the cylindrical portion 87. The outer periphery of the flange 88 is circular when viewed from above.

[0033] The diameter of the dial 89 is smaller than the diameter of the flange 88. The outer peripheral portion of the dial 89 is provided with a plurality of recesses 79 that extend in the vertical direction and are recessed toward the change axis 66. One of the plurality of recesses 79 of the first member 71 engages with a convex portion 76 of a restricting member 75 provided behind the change member 70 in a manner that allows engagement or disengagement. The restricting member 75 restricts the rotational movement of the first member 71 and fixes the change member 70 at an arbitrary position. The cylindrical portion 95 extends downward from the dial 89 in a cylindrical shape. The diameter of the cylindrical portion 95 is shorter than the diameter of the cylindrical portion 87.

[0034] The first member 71 has a portion to be abutted 73 that abuts against the abutting portion 69, and the position of the portion to be abutted 73 that abuts against the abutting portion 69 is changed to change the vertical position of the restricting portion 67. As shown in Figure 5 of (A), the portion to be abutted 73 is a cam surface of an end face cam that extends spirally and obliquely around the change axis 66 along the inner periphery of the second member 72. The portion to be abutted 73 abuts against the abutting portion 69 of the change axis 66. The lower end of the cylindrical portion 95 of the first member 71 abuts against the upper surface of the insertion portion 103 of the plate-like portion 100. The first member 71 is clamped in the vertical direction by the abutting portion 69 of the change axis 66 and the insertion portion 103 of the plate-like portion 100. Therefore, the vertical position of the first member 71 is a fixed position.

[0035] As shown in Figure 2 from (A) to Figure 5As shown in (B), the second member 72 is cylindrical with a hole 55 formed therein through which the change shaft 66 is inserted, and the hole 55 penetrates in the vertical direction. The second member 72 has a cylindrical portion 57 and a flange 58 that projects horizontally from the lower end of the cylindrical portion 57. The second member 72 is supported by the change shaft 66 so as to be movable relative to the first member 71. The second member 72 is movable in the vertical direction. The second member 72 is exposed to the outside of the cover 17. The second member 72 has a second surface 52 that extends horizontally and faces the first surface 51. The second surface 52 is the lower surface of the second member 72 and has a larger area than the upper surface 54 of the second member 72. The second surface 52 is the lower surface of the flange 58. The upper surface 54 is the upper surface of the cylindrical portion 57. The area of the second surface 52 is larger than the area of the upper surface 50 of the cover 74 that covers the upper surface 54 of the second member 72. The outer diameter of the outer periphery of the second surface 52 is larger than the outer diameter of the outer periphery of the upper surface 54. The outer diameter of the outer periphery of the second surface 52 is the same as the outer diameter of the flange 88 of the first member 71. A recess 47 that is circular in a top view and recessed upward is formed in the second surface 52 (see Figure 9 ). A convex portion 48 that projects toward the hole 55 side and extends in the vertical direction is provided on the outer periphery of the recess 47. The cylindrical portion 87 of the first member 71 is fitted into the recess 47. The convex portion 48 engages with a recess 80 formed in the cylindrical portion 87 of the first member 71. Therefore, the second member 72 rotates together with the first member 71 about the change shaft 66.

[0036] As Figure 9 shown, the first stopper 45 is a pin that is inserted through the change shaft 66 below the second member 72. The second stopper 46 is fixed at a position above the first stopper 45. The second stopper 46 and the first stopper 45 clamp the second member 72 together, thereby fixing the second member 72 relative to the change shaft 66 in the vertical direction. The second stopper 46 in this example is a snap ring. The second stopper 46 abuts against the upper surface 54 of the second member 72 from above and is externally inserted into the change shaft 66. The second member 72 is clamped by the first stopper 45 and the second stopper 46 so as to be rotatable relative to the change shaft 66.

[0037] As Figure 4 shown in (A) and Figure 4 (B), the restricting portion 67 moves in the vertical direction according to the vertical movement of the second member 72. The restricting portion 67 moves in the vertical direction together with the change shaft 66 according to the rotation of the second member 72. The restricting portion 67 moves in the vertical direction by an amount corresponding to the vertical movement amount of the second member 72. The cover 74 covers the second member 72 from above. The cover 74 is engaged with the second member 72 in a manner that allows engagement or disengagement and can rotate together with the second member 72.

[0038] The changing member 70 changes the vertical position of the restricting portion 67 according to the distance between the first member 71 and the second member 72. More specifically, the changing member 70 changes the vertical position of the restricting portion 67 according to the vertical distance between the first surface 51 and the second surface 52. The changing member 70 functions as a dial that can rotate about the changing axis 66 in a plan view. Specifically, when the user changes the vertical position of the restricting portion 67, the user operates the second member 72 of the changing member 70 that is exposed to the outside of the hood 17 of the sewing machine 1. The user can also remove the hood 17 of the sewing machine 1 and operate the first member 71. The user places the workpiece C between the first surface 51 of the first member 71 and the second surface 52 of the second member 72, and rotates the second member 72 so that the second surface 52 abuts against the upper surface of the workpiece C. When the first member 71 rotates, the second member 72 also rotates together with the first member 71. Since the shaft 49 of the changing axis 66 is inserted through the slit 102, the changing axis 66 does not rotate according to the rotation of the changing member 70. At this time, the portion of the abutted portion 73 that abuts against the abutting portion 69 can be changed, and the vertical position of the abutting portion 69 can be changed. In this way, the abutting portion 69 moves in the vertical direction according to the vertical position of the portion of the abutted portion 73 against which the abutting portion 69 abuts. According to the rotation operation of the changing member 70 by the user, the changing axis 66 moves in the vertical direction while being guided by the slit 102.

[0039] In this way, the abutted portion 73 changes the vertical position of the restricting portion 67 fixed to the lower end portion of the changing axis 66 by changing the abutting position against the abutting portion 69. The lower end of the moving range of the restricting portion 67 is defined by the insertion portion 104 through which the changing axis 66 is inserted below the restricting portion 67. The rotational positions of the first member 71 and the second member 72 are fixed by the engagement of the convex portion 76 with any one of the plurality of concave portions 79 formed at the lower end portion of the first member 71. In this way, the vertical position of the restricting portion 67 is changed to a position corresponding to the thickness of the workpiece C. The user removes the workpiece C from between the first member 71 and the second member 72, places the workpiece C on the needle plate 3, and forms a stitch on the workpiece C, so that a stitch can be formed on the workpiece C under the condition that the vertical position of the restricting portion 67 is adjusted according to the thickness of the workpiece C.

[0040] Under the condition that the presser bar clamp 82 and the bar 90 are separated in the vertical direction, the vertical positions of the presser bar clamp 82 and the presser bar 8 change according to the vertical position of the feed teeth 19. The presser foot device 9 adjusts the vertical position of the restricting portion 67 to a position where the first wall 61 of the adjusting portion 65 abuts against the restricting portion 67 during one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction by operating the changing member 70. During one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction, the first wall 61 of the adjusting portion 65 abuts against the restricting portion 67. When the adjusting portion 65 cannot move further downward, the second wall 62 of the adjusting portion 65 is separated from the presser bar clamp 82 in the vertical direction, and the acting force of the pressing spring 81 is not transmitted to the presser bar clamp 82. The acting force of the adjusting spring 84 is transmitted to the presser bar clamp 82.

[0041] Refer to Figure 2 (A) to Figure 7 , a case where the vertical position of the restricting portion 67 is changed under the condition that the presser bar 8 is disposed at the lowered position will be described. As Figure 2 (A), Figure 3 (A), Figure 4 (A) and Figure 5 (A), Figure 6 and Figure 9 shown in (A), when the pressing force applied to the presser foot 5 is set to a pressing force suitable for normal sewing, the user disposes the restricting portion 67 at the reference position (first condition F1) under the condition that the upper end of the feed teeth 19 is located above the needle plate 3 and no workpiece C is disposed between the needle plate 3 and the presser foot 5. Under the first condition F1, the presser bar clamp 82 is separated from the bar 90 in the vertical direction and abuts against the second wall 62 of the adjusting portion 65. Under the first condition F1, the adjusting spring 84 is in the most contracted state in the vertical direction, and the second length L2 of the adjusting spring 84 in the vertical direction is less than or equal to the first length L1 of the accommodating portion 85 that accommodates the lower end portion of the adjusting spring 84 in the vertical direction. Under the first condition F1, when sewing with the workpiece C disposed between the needle plate 3 and the presser foot 5, the acting force from the pressing spring 81 is always transmitted to the presser foot 5 during one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction.

[0042] As Figure 2 (B), Figure 3 (B), Figure 4 (B) and Figure 5 (B), Figure 7 and Figure 9As shown in (B), when the pressing force applied to the presser foot 5 is set to a pressing force suitable for curved sewing, the user operates the changing member 70 from the first condition F1, so that the restricting portion 67 rises by an amount corresponding to the thickness of the workpiece C (e.g., 4 mm) from the reference position (second condition F2). Under the second condition F2, the presser bar clamp 82 is separated in the vertical direction of the bar 90 and is also separated from the second wall 62 of the adjusting portion 65 in the vertical direction. Under the second condition F2, when sewing with a workpiece C having a thickness of 4 mm disposed between the needle plate 3 and the presser foot 5, during the period when the restricting portion 67 and the first wall 61 of the adjusting portion 65 are separated in the vertical direction during one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction, the acting force from the pressing spring 81 is transmitted to the presser foot 5. On the other hand, during the period when the restricting portion 67 and the first wall 61 of the adjusting portion 65 are in contact with each other in the vertical direction, the acting force from the pressing spring 81 is not transmitted to the presser foot, and the acting force of the adjusting spring 84 is transmitted to the presser foot 5. By operating the changing member 70 according to the thickness of the workpiece C, the user adjusts the vertical position of the restricting portion 67, whereby it is possible to change the pressing force applied to the workpiece C during one reciprocation of the needle bar 31 of the sewing machine 1 in the vertical direction.

[0043] Refer to Figure 8 , the case where the presser bar 8 is disposed at the raised position will be described. As Figure 8 shown, when operating the lever 90 from the Figure 6 first condition F1 such that the convex portion 93 of the lever 90 abuts against the presser bar clamp 82, the presser bar clamp 82 and the presser bar 8 are pushed upward by the convex portion 93, and the presser foot 5 is separated from the needle plate 3 in the vertical direction. In this state, the user performs the operation of disposing the workpiece C between the needle plate 3 and the presser foot 5, and performs the operation of attaching the presser foot device 9 to the lower end of the presser bar 8 or detaching the presser foot device 9 from the lower end of the presser bar 8.

[0044] Refer to Figure 10 , the relationship between the vertical position of the needle bar 31, the vertical position of the feed teeth 19, the vertical position of the presser bar clamp 82, the pressing force applied by the presser foot 5 to the workpiece C, and the vertical interval between the restricting portion 67 and the first wall 61 of the adjusting portion 65 corresponding to the rotation angle of the sewing machine motor 2 will be described. In the sewing machine 1 of the present embodiment, when the sewing machine motor 2 rotates one week, the needle bar 31 of the sewing machine 1 reciprocates once in the vertical direction. In Figure 10 the "presser foot pressing force", minute change amounts caused by the displacement amount of the adjusting spring 84 accompanying the vertical movement of the feed teeth 19 and the displacement amount of the pressing spring 81 are ignored. In Figure 10In this case, the pressing force applied to the presser foot 5 during period P1 is set to 100, and the pressing force applied to the presser foot 5 during period P2 is shown. Period P1 is a period during which the first wall 61 of the adjustment unit 65 and the restricting unit 67 are separated in the vertical direction. Period P2 is a period during which the first wall 61 of the adjustment unit 65 and the restricting unit 67 are in contact with each other in the vertical direction. The pressing force applied to the presser foot 5 during period P2 is smaller than the pressing force applied to the presser foot 5 during period P1. During period P2, the presser bar clamp 82 descends downward relative to the second wall 62 of the adjustment unit 65 by the acting force of the adjustment spring 84 to a position where the presser foot 5 comes into contact with the workpiece C to be sewn. As a result, the second wall 62 and the presser bar clamp 82 are separated from each other in the vertical direction. During period P1, the presser foot 5 is lifted by the feed teeth 19, and the presser bar 8 is pressed upward. As a result, the presser bar clamp 82 moves upward against the acting force of the adjustment spring 84 and comes into contact with the second wall 62 in the vertical direction. Since the adjustment unit 65 can move upward, the presser bar clamp 82 moves upward together with the adjustment unit 65 having the second wall 62.

[0045] That is, in the case of the first state where the upper end of the feed teeth 19, i.e., the tooth upper end 18, is located above the upper end of the needle plate 3, i.e., the plate upper end 27, and the adjustment unit 65 and the restricting unit 67 are separated, the adjustment unit 65 comes into contact with the presser bar clamp 82, and the acting force of the pressing spring 81 is transmitted to the presser bar 8. In the case of the first state, the sewing needle 35 is located above the workpiece C to be sewn. That is, while the sewing machine 1 conveys the workpiece C to be sewn in the conveying direction by the feed teeth 19, the pressing force of the pressing spring 81 is applied to the presser foot 5. As a result, the sewing machine 1 can stably convey the workpiece C to be sewn in the conveying direction while firmly clamping the workpiece C to be sewn in the vertical direction by the presser foot 5 and the feed teeth 19.

[0046] On the other hand, in the case of the second state where the tooth upper end 18 is located below the plate upper end 27 and the adjustment unit 65 and the restricting unit 67 are in contact with each other, the adjustment unit 65 and the presser bar clamp 82 are separated from each other in the vertical direction, and the acting force of the pressing spring 81 is not transmitted to the presser bar 8. The second state includes the period during which the sewing needle 35 pierces the workpiece C to be sewn. As a result, the sewing machine 1 can make the force applied to the presser foot 5 during period P2 when the sewing needle 35 pierces the workpiece C to be sewn smaller than that of conventional sewing machines. Therefore, compared with conventional sewing machines, the sewing machine 1 can more easily change the orientation of the workpiece C to be sewn during sewing and can more easily sew a curved portion.

[0047] In the above-described embodiment, the sewing machine 1, the sewing machine motor 2, the needle plate 3, the presser foot 5, the presser bar 8, the cover 17, the upper end of the teeth 18, the feed teeth 19, the needle insertion hole 25, the opening 26, the upper end of the plate 27, the needle bar 31, and the sewing needle 35 are respectively examples of the sewing machine, the sewing machine motor, the needle plate, the presser foot, the presser bar, the cover, the upper end of the teeth, the feed teeth, the needle insertion hole, the opening, the upper end of the plate, the needle bar, and the sewing needle of the present invention. The first stopper 45, the second stopper 46, the first surface 51, the second surface 52, the upper surface 54, the hole 55, the adjustment portion 65, the change shaft 66, the restricting portion 67, the abutting portion 69, the change member 70, the first member 71, the second member 72, the portion to be abutted 73, the pressing spring 81, and the adjustment spring 84 are respectively examples of the first stopper, the second stopper, the first surface, the second surface, the upper surface, the hole, the adjustment portion, the change shaft, the restricting portion, the abutting portion, the change member, the first member, the second member, the portion to be abutted, the pressing spring, and the adjustment spring.

[0048] The sewing machine 1 of the above-described embodiment includes a sewing machine motor 2, a needle bar 31, a needle plate 3, feed teeth 19, a presser bar 8, a presser bar clamp 82, an adjustment portion 65, a pressing spring 81, a restricting portion 67, and a change member 70. The needle bar 31 can be fitted with a sewing needle 35 at its lower end and moves in the vertical direction according to the drive of the sewing machine motor 2. The needle plate 3 is formed with a needle insertion hole 25 through which the sewing needle 35 passes. The feed teeth 19 project or retract from an opening 26 formed in the needle plate 3 according to the drive of the sewing machine motor 2, and convey the workpiece C placed on the needle plate 3. The presser bar 8 can be attached with a presser foot 5 at its lower end and moves in the vertical direction synchronously with the drive of the feed teeth 19. The presser bar clamp 82 is fixed to the presser bar 8. The adjustment portion 65 can move in the vertical direction. The pressing spring 81 can apply a downward force to the presser bar 8 via the adjustment portion 65 and the presser bar clamp 82. When the restricting portion 67 abuts against the adjustment portion 65, the restricting portion 67 restricts the pressing spring 81 from transmitting the acting force to the presser bar 8. The change member 70 has a first member 71 and a second member 72 that is supported so as to be movable relative to the first member 71, and changes the vertical position of the restricting portion 67 according to the distance between the first member 71 and the second member 72. When the upper end of the teeth 18, i.e., the upper end of the feed teeth 19, is located above the upper end of the needle plate 3, i.e., the upper end of the plate 27, and the adjustment portion 65 is separated from the restricting portion 67 in a first state, the adjustment portion 65 abuts against the presser bar clamp 82, and the acting force of the pressing spring 81 is transmitted to the presser bar 8. When the upper end of the teeth 18 is located below the upper end of the plate 27 and the adjustment portion 65 abuts against the restricting portion 67 in a second state, the adjustment portion 65 and the presser bar clamp 82 are separated in the vertical direction, and the acting force of the pressing spring 81 is not transmitted to the presser bar 8.

[0049] The sewing machine 1 enables the user to adjust the timing for switching whether to transmit the acting force of the pressing spring 81 to the presser bar 8 or not by a relatively simple operation of changing the distance between the first member 71 and the second member 72. Therefore, the contribution of the sewing machine 1 is that the operation of adjusting the timing for changing the acting force applied to the presser foot 5 installed at the lower end of the presser bar 8 in linkage with the sewing machine motor 2 according to the workpiece C to be sewn is simpler than before.

[0050] The sewing machine 1 is provided with an adjustment spring 84 which is disposed below the adjustment portion 65 and applies a downward force to the presser bar 8 via the presser bar clamp 82 at least in the second state. The acting force of the adjustment spring 84 is smaller than the acting force of the pressing spring 81. The sewing machine 1 can apply a downward force to the presser foot 5 installed at the lower end of the presser bar 8 with the acting force of the adjustment spring 84 which is smaller than the acting force of the pressing spring 81 at least in the second state. Therefore, the contribution of the sewing machine 1 is to achieve stable sewing by eliminating the state (period) in which the presser foot 5 is completely disengaged.

[0051] The first member 71 has a first surface 51 that extends in a horizontal direction orthogonal to the vertical direction. The second member 72 has a second surface 52 that extends in the horizontal direction and faces the first surface 51. The changing member 70 changes the vertical position of the restricting portion 67 according to the vertical distance between the first surface 51 and the second surface 52. The contribution of the first member 71 and the second member 72 of the sewing machine 1 is that the operation of adjusting the distance between the first surface 51 and the second surface 52 according to the workpiece C to be sewn is easier than the case where the first surface 51 and the second surface 52 are surfaces extending in the vertical direction.

[0052] The second member 72 is movable in the vertical direction. The vertical position of the first member 71 is a fixed position. The contribution of the sewing machine 1 is that the operation of adjusting the timing for changing the acting force applied to the presser foot 5 provided at the lower end of the presser bar 8 in linkage with the sewing machine motor 2 according to the workpiece C to be sewn is set as a relatively simple operation of moving the position of the first member 71 in the vertical direction.

[0053] The restricting portion 67 moves in the vertical direction according to the vertical movement of the second member 72. The contribution of the sewing machine 1 is that the operation of adjusting the timing for changing the acting force applied to the presser foot 5 provided at the lower end of the presser bar 8 in linkage with the sewing machine motor 2 according to the workpiece C to be sewn is set as a relatively simple operation of moving the second member 72 in the vertical direction.

[0054] The second surface 52 is the lower surface of the second member 72, and has an area larger than that of the upper surface 54 of the second member 72. The contribution of the second member 72 of the sewing machine 1 is that, compared with the case where the area of the second surface 52 is equal to or smaller than the area of the upper surface 54 of the second member 72, it is easier to confirm the position of the second surface 52 and easier to adjust the distance between the first surface 51 and the second surface 52.

[0055] The change member 70 has a change shaft 66 that extends parallel to the presser bar 8 and is connected to the restricting portion 67. The second member 72 is provided so as to be rotatable relative to the change shaft 66. The restricting portion 67 moves in the vertical direction together with the change shaft 66 according to the rotation of the second member 72. The contribution of the second member 72 and the change shaft 66 of the sewing machine 1 is that the structure of the change member 70 is relatively simple.

[0056] A hole 55 through which the change shaft 66 is inserted is formed in the second member 72. The sewing machine 1 has a first stopper 45 and a second stopper 46. The first stopper 45 is inserted through the change shaft 66 below the second member 72. The second stopper 46 is fixed at a position above the first stopper 45 and fixes the second member 72 relative to the change shaft 66 in the vertical direction by clamping the second member 72 together with the first stopper 45. The contribution of the first stopper 45 and the second stopper 46 of the sewing machine 1 is that a structure for fixing the position of the second member 72 relative to the change shaft 66 in the vertical direction in a manner that allows the second member 72 to rotate relative to the change shaft 66 is achieved with a relatively simple structure.

[0057] The sewing machine 1 has an abutting portion 69 provided on the change shaft 66. The first member 71 has an abutting portion 73 that abuts against the abutting portion 69, and the position of the restricting portion 67 in the vertical direction is changed by changing the abutting position where the abutting portion 73 abuts against the abutting portion 69. The contribution of the abutting portion 69 and the abutting portion 73 of the sewing machine 1 is that a structure in which the restricting portion 67 moves in the vertical direction together with the change shaft 66 according to the rotation of the second member 72 is achieved with a relatively simple structure.

[0058] The sewing machine 1 has a cover 17 covering the sewing machine motor 2. The first surface 51 and the second member 72 are exposed to the outside of the cover 17. Compared with the case where the sewing machine 1 and the first surface 51 and the second member 72 are arranged inside the cover 17, the operation of adjusting the distance between the first surface 51 and the second surface 52 according to the workpiece C to be sewn is easier. By sandwiching the workpiece C to be sewn between the first surface 51 and the second surface 52, the sewing machine 1 can easily adjust the distance between the first surface 51 and the second surface 52 to a distance corresponding to the thickness of the workpiece C. The first surface 51 of the present embodiment extends in the horizontal direction, and the vertical position of the first surface 51 is the same as the vertical position of the upper surface of the cover 17. Therefore, compared with the case where the vertical position of the first surface 51 is different from the vertical position of the upper surface of the cover 17, the operation of clamping the workpiece C using the first surface 51 and the second surface 52 is easier.

[0059] The sewing machine of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, the following deformations can be appropriately applied.

[0060] The structures of the sewing machine 1 and the presser foot device 9 can be appropriately changed. The sewing machine 1 can also be an industrial sewing machine. The conveying direction of the workpiece C by the sewing machine 1 can be appropriately changed.

[0061] The types, arrangements, etc. of the pressing spring 81 and the adjusting spring 84 can be appropriately changed. The pressing spring 81 and the adjusting spring 84 can also be not externally inserted into the pressure bar 8 respectively. The lower end portion of the adjusting spring 84 may not be accommodated in the accommodating portion 85. The second length L2 in the vertical direction in the most contracted state of the adjusting spring 84 may also be larger than the first length L1. The adjusting spring 84 can also be omitted. The adjusting spring 84 only needs to be able to apply a downward force to the pressure bar 8 via the pressure bar hoop 82 at least in the second state. The structure of the adjusting mechanism 68 can be appropriately changed.

[0062] The structure of the changing member 70 can be appropriately changed. It can also be that the first member has a first surface extending in the vertical direction, and the second member has a second surface opposite to the first surface of the first member and extending in the vertical direction. In this case, it can also be that the changing member includes conversion members such as a rack and pinion, a bevel gear, and a worm and worm gear pair, and the horizontal movement of the first member and the second member is converted into vertical movement by the conversion members, so that the restricting portion 67 moves in the vertical direction. The vertical position of the second member 72 can be a fixed position, and the first member 71 provided below the second member 72 can also be movable in the vertical direction. In this case, the changing shaft 66, the abutting portion 69, and the abutted portion 73 can be omitted, and the restricting portion 67 can also move in the vertical direction according to the vertical movement of the first member 71.

[0063] The change member 70 may also include the change shaft 66 as the second member, and the second member 72 may be omitted. In this case, the first member 71 may be rotated around the change shaft 66 to adjust the upper surface of the sewn object C to a predetermined position of the change shaft 66 while the sewn object C is placed on the first surface 51, thereby moving the limiting portion 67 to a vertical position corresponding to the thickness of the sewn object C. The predetermined position may be set appropriately, for example, it may be a vertical position where the upper end of the change shaft 66 is the upper surface of the sewn object C, or it may be a position where the first stopper 45 inserted through the change shaft 66 abuts against the upper surface of the sewn object C. When the distance between the first member 71 and the second member 72 is changed, the sewn object C may not be arranged between the first surface 51 and the second surface 52. For example, when the distance between the first component 71 and the second component 72 is set to a distance corresponding to the sewing object C with a known thickness, the distance between the first component 71 and the second component 72 of the sewing machine 1 can be measured and adjusted, or the distance between the first component 71 and the second component 72 of the sewing machine 1 can be adjusted by referring to the memory provided in the change component 70.

[0064] The change member 70 may include a cam surface that guides the abutment portion fixed to the change shaft 66, or may include an abutment portion composed of a cam surface and a cam groove on the change shaft 66, and the change member 70 may include a cam that abuts against the abutment portion of the change shaft 66 as an abutted portion. The change member 70 may also be a structure other than the abutment portion and the abutted portion. For example, the change member 70 may also be composed of a pinion and a rack fixed to the change shaft 66 and engaged with the pinion. In addition to the turntable shape, the change member 70 may also be a rod or the like. The structure of the limiting member 75 that limits the rotation of the change member 70 may be appropriately changed according to the structure of the change member 70. The configuration of the change member 70 relative to the pressure rod 8 may be appropriately changed. The change member 70 is preferably arranged in a place that is easy for the user to operate and does not interfere with the sewing operation.

[0065] The area of ​​the second surface 52 may not be larger than the area of ​​the upper surface 54 of the second member 72. The change shaft 66 may be omitted, and may not extend parallel to the pressure rod 8. The hole 55 through which the change shaft 66 is inserted may not be formed in the second member 72, and the second member 72 may not be provided to be rotatable relative to the change shaft 66. The sewing machine 1 may not have at least one of the first stopper 45 and the second stopper 46. The second member 72 may not be clamped by the first stopper 45 and the second stopper 46. The first surface 51 and the second member 72 may not be exposed to the outside of the cover 17. The upper surface of the cover 17 may function instead of the first surface 51 of the first member 71, and the first surface 51 of the first member 71 may not be provided separately from the upper surface of the cover 17.

[0066] The shape of the adjustment part 65 can be appropriately changed, and it can be in a flat plate shape, a cuboid shape, a spherical shape, etc., instead of a crank shape. In the adjustment part 65, the shape of at least any one of the first wall 61 to the fourth wall 64 can be changed, and at least any one of the first wall 61 to the fourth wall 64 can be appropriately omitted. The structure for changing the vertical position of the change restricting part 67 can be appropriately changed. The presser bar clamp 82 may not have the accommodating part 85, and the second length L2 may be greater than the first length L1.

[0067] Explanation of reference numerals

[0068] 1: Sewing machine, 2: Sewing machine motor, 3: Needle plate, 5: Presser foot, 8: Presser bar, 17: Cover, 18: Upper end of tooth, 19: Feed tooth, 25: Needle hole, 26: Opening, 27: Upper end of plate, 31: Needle bar, 35: Needle, 45: First stopper, 46: Second stopper, 51: First surface, 52: Second surface, 54: Upper surface, 55: Hole, 65: Adjustment part, 66: Change shaft, 67: Restricting part, 69: Contact part, 70: Change member, 71: First member, 72: Second member, 73: Contacted part, 81: Pressing spring, 84: Adjustment spring.

Claims

1. A sewing machine, characterized in that: have: Sewing machine motors; A needle bar, which can be equipped with a needle at the lower end and moves in the up and down direction according to the driving of the sewing machine motor; A needle plate, formed with a needle hole for the needle to penetrate; A feed tooth protrudes from or retracts into the opening formed in the needle plate according to the driving of the sewing machine motor, so as to feed the sewn object placed on the needle plate; A pressure rod, capable of mounting a pressure foot at the lower end thereof, and moving in the up-down direction synchronously with the driving of the feed teeth; A pressure rod clamp, fixed to the pressure rod; an adjusting portion, capable of moving along the up-down direction; A pressing spring can apply force to the pressure rod downward via the adjusting portion and the pressure rod clamp; a limiting portion, which, when in contact with the adjusting portion, limits the force transmitted by the pressing spring to the pressing rod; as well as a changing member having a first member and a second member movable relative to the first member, and changing the vertical position of the limiting portion according to the distance between the first member and the second member; In the first condition where the upper end of the feed tooth, i.e., the upper end of the tooth, is located above the upper end of the needle plate, i.e., the upper end of the plate, and the adjustment portion is separated from the limiting portion, the adjustment portion abuts against the pressure rod clamp, and the force of the pressing spring is transmitted to the pressure rod. In the second condition where the upper end of the tooth is located below the upper end of the plate and the adjustment portion abuts against the restriction portion, the adjustment portion and the pressure rod clamp are separated in the vertical direction and the urging force of the pressure spring is not transmitted to the pressure rod.

2. The sewing machine according to claim 1, characterized in that: The device further comprises an adjustment spring, which is arranged below the adjustment portion, and at least in the case of the second condition, the adjustment spring applies force to the pressure rod downward via the pressure rod clamp. The acting force of the adjustment spring is smaller than the acting force of the pressing spring.

3. The sewing machine according to claim 1, characterized in that: The first member has a first surface extending in a horizontal direction perpendicular to the up-down direction. The second member has a second surface extending in the horizontal direction and facing the first surface, The changing member changes the position of the restriction portion in the up-down direction according to the distance between the first surface and the second surface in the up-down direction.

4. The sewing machine according to claim 3, characterized in that: The second member is movable in the up-down direction. The position of the first member in the up-down direction is a fixed position.

5. The sewing machine according to claim 4, characterized in that The restriction portion moves in the up-down direction according to the up-down movement of the second member.

6. The sewing machine according to claim 5, characterized in that The second surface is a lower surface of the second member, and an area of ​​the second surface is larger than an upper surface of the second member.

7. The sewing machine according to claim 3, characterized in that: The changing member has a changing shaft extending parallel to the pressure rod and connected to the restricting portion. The second member is arranged to be rotatable relative to the change axis, The restricting portion moves in the up-down direction together with the change shaft in accordance with the rotation of the second member.

8. The sewing machine according to claim 7, characterized in that The second member has a hole formed therein through which the change shaft is inserted. The sewing machine also has: a first stopper inserted through the change shaft below the second member; and The second stopper is fixed above the first stopper, and fixes the second member relative to the change axis in the up-down direction by clamping the second member together with the first stopper.

9. The sewing machine according to claim 8, characterized in that The sewing machine further comprises a contact portion provided on the change shaft. The first member includes an abutted portion that abuts against the abutting portion, and the abutted portion changes a position of the restricting portion in the up-down direction by changing a contact position with the abutting portion.

10. The sewing machine according to claim 3, characterized in that The sewing machine further comprises a cover covering the sewing machine motor. The first surface and the second member are exposed to the outside of the cover.

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