Sewing machine

Abstract

To provide a sewing machine capable of adjusting the feed amount with good operability.SOLUTION: A sewing machine includes a feed dog that feeds a sewing object, a knee lever that is operated with the knee of an operator so as to be pushed in a prescribed direction from an initial position, a lever sensor that detects the push-in amount of the knee lever from the initial position, and a controller that outputs the control command to change the feed amount of the feed dog based on a detection signal of the lever sensor.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] In the technical field related to sewing machines, there is known a sewing machine as disclosed in Patent Document 1, in which the feed amount of feed teeth can be adjusted. Also, there is known a sewing machine having a presser lifter for raising the presser as disclosed in Patent Document 2. Further, there is known a sewing machine provided with a knee lever as disclosed in Patent Document 3.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology disclosed in this specification aims to provide a sewing machine capable of operably adjusting the feed amount.

Means for Solving the Problems

[0005] This specification discloses a sewing machine. The sewing machine includes feed teeth for feeding a sewing object, a knee lever that is operated to be pushed in a predetermined direction from an initial position by an operator's knee, a lever sensor that detects the amount of pushing of the knee lever from the initial position, and a controller that outputs a control command for changing the feed amount of the feed teeth based on the detection signal of the lever sensor.

Effects of the Invention

[0006] According to the technology disclosed in this specification, a sewing machine capable of operably adjusting the feed amount is provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings. In the embodiments, the terms left, right, front, rear, top, and bottom are used to describe the positional relationships of the respective parts. These terms indicate the relative positions or directions with respect to the center of the sewing machine 1.

[0009] [First Embodiment] The first embodiment will be described.

[0010] <Sewing Machine> FIG. 1 is a perspective view showing the sewing machine 1 according to the present embodiment. FIG. 2 is a block diagram showing the sewing machine 1 according to the present embodiment. In the present embodiment, the sewing machine 1 is an industrial sewing machine. The sewing machine 1 is a so-called straight stitch sewing machine.

[0011] The sewing machine 1 includes a sewing machine frame 3, a needle bar 5, a balance 6, a needle plate 7, a presser 8, a thread conditioner 9, feed teeth 10, a bobbin 11, a sewing machine motor 12, a feed motor 13, a presser motor 14, a sewing machine power transmission mechanism 15, a feed amount adjustment mechanism 16, a presser lifting mechanism 17, a pedal 18, an operation panel 19, a knee lever 20, a lever sensor 21, and a controller 22.

[0012] The sewing machine frame 3 is installed on the upper surface of the sewing machine table 2. The sewing machine table 2 is supported by table legs. A chair is installed on the rear side of the sewing machine table 2. The operator operates the sewing machine 1 while sitting on the chair.

[0013] The needle bar 5 holds the sewing machine needle 4. The needle bar 5 reciprocates in the vertical direction. The needle bar 5 is supported by the sewing machine frame 3. The sewing machine needle 4 has a thread passage hole through which the upper thread passes. The sewing machine needle 4 holds the upper thread on the inner surface of the thread passage hole. As the needle bar 5 reciprocates in the vertical direction, the sewing machine needle 4 reciprocates in the vertical direction while holding the upper thread.

[0014] The balance 6 supplies the upper thread to the sewing needle 4. The balance 6 reciprocates in the vertical direction. The balance 6 is supported by the sewing machine frame 3. The balance 6 reciprocates in the vertical direction while holding the upper thread. The balance 6 has a holding hole through which the upper thread passes. The balance 6 holds the upper thread on the inner surface of the holding hole. By reciprocating in the vertical direction, the balance 6 pays out the upper thread used for sewing the object to be sewn or pulls up the upper thread.

[0015] The needle plate 7 supports the object to be sewn from below. The needle plate 7 supports the object to be sewn below the needle bar 5. The needle plate 7 is disposed below the needle bar 5. The sewing needle 4 held by the needle bar 5 and the needle plate 7 face each other. The needle plate 7 has a needle hole through which the sewing needle 4 can pass. The sewing needle 4 passing through the object to be sewn supported by the needle plate 7 passes through the needle hole.

[0016] The presser 8 presses the object to be sewn supported by the needle plate 7 from above. The presser 8 is disposed at least partially around the sewing needle 4. The presser 8 is supported by the sewing machine frame 3. The presser 8 is movable in the vertical direction. A presser spring is disposed around the upper end of the presser 8. The presser spring generates an elastic force that moves the presser 8 downward. The presser 8 is pressed against the object to be sewn from above by the elastic force generated by the presser spring.

[0017] The thread tensioner 9 applies tension to the upper thread supplied to the sewing needle 4 between the balance 6 and the needle bar 5. The thread tensioner 9 is supported by the sewing machine frame 3.

[0018] The feed teeth 10 operate to feed the object to be sewn supported by the needle plate 7 forward or backward. The feed teeth 10 feed the object to be sewn by moving along a predetermined feed path. The feed teeth 10 are disposed below the needle plate 7. The feed teeth 10 move along the feed path and protrude upward from the upper surface of the needle plate 7 through an opening provided in the needle plate 7. When feeding the object to be sewn, at least a part of the feed teeth 10 protrudes upward from the upper surface of the needle plate 7 through the opening provided in the needle plate 7.

[0019] The bobbin case 11 supplies the lower thread to the sewing target. The bobbin case 11 is disposed below the feed dog 10. The bobbin case 11 is rotatable.

[0020] The sewing machine motor 12 generates power for operating each of the needle bar 5, the feed dog 10, and the bobbin case 11. The sewing machine motor 12 generates power for reciprocating the needle bar 5 in the vertical direction. The sewing machine motor 12 generates power for rotating the bobbin case 11. The sewing machine motor 12 generates power for moving the feed dog 10 along the feed track. The sewing machine motor 12 includes a servo motor. The sewing machine motor 12 is supported by the right portion of the sewing machine frame 3.

[0021] The feed motor 13 generates power for changing the feed amount of the feed dog 10. The feed motor 13 includes a pulse motor. The feed motor 13 is disposed inside the sewing machine frame 3.

[0022] The presser motor 14 generates power for raising the presser 8. The presser motor 14 is disposed inside the sewing machine frame 3.

[0023] The sewing machine power transmission mechanism 15 operates each of the needle bar 5, the feed dog 10, and the bobbin case 11 based on the power generated by the sewing machine motor 12. The sewing machine power transmission mechanism 15 transmits the power generated by the sewing machine motor 12 to each of the needle bar 5, the feed dog 10, and the bobbin case 11.

[0024] The needle bar 5 and the sewing machine needle 4 held by the needle bar 5 reciprocate in the vertical direction based on the power generated by the sewing machine motor 12. The bobbin case 11 rotates so that the lower thread is supplied to the sewing target in synchronization with the reciprocating movement of the needle bar 5 in the vertical direction. The feed dog 10 swings in the front-rear direction and the vertical direction so as to feed the sewing target forward or backward in synchronization with the reciprocating movement of the needle bar 5 in the vertical direction. The sewing machine 1 sews the sewing target by the cooperation of the sewing machine needle 4 held by the needle bar 5 and the bobbin case 11.

[0025] The feed amount adjustment mechanism 16 changes the feed amount of the feed teeth 10 based on the power generated by the feed motor 13. When the feed teeth 10 are moving based on the power generated by the sewing machine motor 12, the feed amount of the feed teeth 10 is changed by changing the amplitude of the feed teeth 10 in the front-rear direction.

[0026] The presser lifting mechanism 17 raises the presser 8 based on the power generated by the presser motor 14. The presser lifting mechanism 17 transmits the power generated by the presser motor 14 to the presser 8.

[0027] The pedal 18 is operated by the operator of the sewing machine 1. The operator operates the pedal 18 with the foot. Based on the operation state of the pedal 18, the sewing machine motor 12 is driven or stopped. The operation signal generated by operating the pedal 18 is transmitted to the controller 22.

[0028] The operation panel 19 includes a flat panel display and a touch panel. The operation panel 19 is operated by the operator of the sewing machine 1. The operation panel 19 is provided on the sewing machine frame 3. The operator operates the operation panel 19 with a finger. The operation panel 19 is an example of an input device. The input signal generated by operating the operation panel 19 is transmitted to the controller 22.

[0029] The knee lever 20 is operated by the operator. The knee lever 20 is rotatably supported under the sewing machine table 2. The knee lever 20 is rotatable within a predetermined rotation range. The knee lever 20 rotates substantially to the right or left. The operator operates the knee lever 20 with the knee. For example, the operator operates the knee lever 20 by pushing it to the right with the knee of the right foot.

[0030] In the present embodiment, the operator can change the feed amount of the feed teeth 10 by operating the knee lever 20. The operator can switch the feed direction of the feed teeth 10 by operating the knee lever 20. The feed direction of the feed teeth 10 is forward or backward.

[0031] The lever sensor 21 detects the amount of depression of the knee lever 20. The amount of depression of the knee lever 20 includes the amount of rotation of the knee lever 20. The lever sensor 21 detects the direction of rotation of the knee lever 20. The direction of rotation of the knee lever 20 is to the right or left. The lever sensor 21 detects the position of the knee lever 20 within the range of rotation of the knee lever 20. The detection signal of the lever sensor 21 is transmitted to the controller 22.

[0032] The controller 22 has a processor such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface including an input / output circuit capable of inputting and outputting signals and data. The controller 22 controls each of the sewing machine motor 12, the feed motor 13, and the presser motor 14. The operation signal from the pedal 18, the input signal from the operation panel 19, and the detection signal of the lever sensor 21 are input to the controller 22.

[0033] The controller 22 controls the sewing machine motor 12 based on the operation signal from the pedal 18. When the pedal 18 is operated so that the front part of the pedal 18 moves downward, the controller 22 drives the sewing machine motor 12. When the sewing machine motor 12 is driven, the sewing target is sewn. When the sewing target is sewn, the presser 8 presses the sewing target from above. When the pedal 18 is operated so that the rear part of the pedal 18 moves downward, the controller 22 stops the sewing machine motor 12.

[0034] Based on the detection signal of the lever sensor 21, the controller 22 controls the feed motor 13 so that the feed amount of the feed teeth 10 changes. The controller 22 outputs a control command for changing the feed amount of the feed teeth 10 to the feed motor 13 based on the detection signal of the lever sensor 21. Based on the detection signal of the lever sensor 21, the controller 22 controls the feed motor 13 so that the feed direction of the feed teeth 10 is switched. The controller 22 outputs a control command for switching the feed direction of the feed teeth 10 to the feed motor 13 based on the detection signal of the lever sensor 21.

[0035] <Knee lever> FIG. 3 is a view showing the knee lever 20 according to the present embodiment. The knee lever 20 is disposed below the sewing machine table 2. The knee lever 20 is rotatably supported by the sewing machine table 2. The knee lever 20 includes a pad 20A, a rod 20B, a bracket 20C, a support shaft 20D, and a torsion spring 20E.

[0036] The pad 20A is a member against which the operator's knee is applied. The rod 20B supports the pad 20A. The pad 20A is fixed to the lower end of the rod 20B. The bracket 20C is fixed to at least a part of the sewing machine table 2. The support shaft 20D is rotatably supported by the bracket 20C. The upper end of the rod 20B is fixed to the support shaft 20D. The support shaft 20D rotatably supports the pad 20A via the rod 20B. The torsion spring 20E is disposed around the support shaft 20D. At least a part of the torsion spring 20E is connected to the bracket 20C.

[0037] The operator operates to push the knee lever 20 to the right with, for example, the knee of the right foot applied to the pad 20A. By the pushing operation of the knee lever 20 by the operator, the knee lever 20 rotates to the right.

[0038] The knee lever 20 is rotatable within a predetermined range of rotation. When the knee lever 20 is not being operated by the operator, it is positioned at the initial position Po. The initial position Po is the left end of the rotation range of the knee lever 20. The knee lever 20 is operated to be pushed rightward from the initial position Po by the operator's knee.

[0039] The torsion spring 20E generates an elastic force that moves the knee lever 20 to the initial position Po. The torsion spring 20E generates a biasing force that biases the knee lever 20 to the left. When the knee lever 20 is not being operated by the operator, it is positioned at the initial position Po by the biasing force of the torsion spring 20E. Incidentally, when the knee lever 20 is not being operated by the operator, a stopper (not shown) is provided to maintain the position of the knee lever 20 at the initial position Po. When the operator wants to change the feed amount of the feed teeth 10, the operator performs a pushing operation to push the knee lever 20 rightward against the biasing force of the torsion spring 20E.

[0040] <Adjustment method> Figure 4 is a diagram for explaining the method of adjusting the feed amount of the feed teeth 10 according to the present embodiment. In the graph shown in Figure 4, the horizontal axis indicates the amount of pushing of the knee lever 20 from the initial position Po. The vertical axis indicates the feed amount of the feed teeth 10.

[0041] The knee lever 20 is rotatable within a rotation range between the initial position Po and the maximum position Pm. The initial position Po is the left end of the rotation range of the knee lever 20. The maximum position Pm is the right end of the rotation range of the knee lever 20. The amount of pushing of the knee lever 20 at the initial position Po is 0. The amount of pushing of the knee lever 20 from the initial position Po at the maximum position Pm is the maximum value Sm.

[0042] In addition, a direction switching position Pi is defined between an initial position Po and a maximum position Pm within the rotation range of the knee lever 20. The direction switching position Pi is in the middle of the rotation range of the knee lever 20. The amount of depression of the knee lever 20 from the initial position Po at the direction switching position Pi is the intermediate value Si. In the rotation range of the knee lever 20, the distance between the direction switching position Pi and the maximum position Pm is shorter than the distance between the direction switching position Pi and the initial position Po. The difference between the intermediate value Si and the maximum value Sm is smaller than the intermediate value Si.

[0043] The feed teeth 10 feed the sewing target forward or backward. In the following description, the forward direction is appropriately referred to as the positive direction, and the backward direction is appropriately referred to as the reverse direction. Also, feeding the sewing target forward is appropriately referred to as forward feeding, and feeding the sewing target backward is appropriately referred to as reverse feeding.

[0044] The feed teeth 10 can perform forward feeding for feeding the sewing target in the positive direction and reverse feeding for feeding the sewing target in the reverse direction.

[0045] In the graph shown in FIG. 4, when the feed amount is a positive value greater than 0, it means that the sewing target is in a forward feeding state where it is fed forward. When the feed amount is a negative value smaller than 0, it means that the sewing target is in a reverse feeding state where it is fed backward. When the feed amount is 0, it means that the sewing target is not being fed.

[0046] As shown in FIG. 4, the controller 22 reduces the feed amount of the feed teeth 10 as the amount of depression of the knee lever 20 from the initial position Po increases, based on the detection signal of the lever sensor 21. The controller 22 increases the rate of change of the feed amount of the feed teeth 10 as the amount of depression of the knee lever 20 from the initial position Po increases, based on the detection signal of the lever sensor 21.

[0047] The rate of change of the feed amount refers to the amount of change in the feed amount per unit amount of depression of the knee lever 20. When the feed amount for forward feeding is a positive value and the feed amount for reverse feeding is a negative value, reducing the feed amount means reducing the absolute value of the feed amount for forward feeding and increasing the absolute value of the feed amount for reverse feeding.

[0048] When the knee lever 20 is disposed at the initial position Po, the feed amount of the feed teeth 10 is set to the initial value NF. The initial value NF is set, for example, by operating the operation panel 19. The controller 22 sets the initial value NF based on the input signal from the operation panel 19. When the knee lever 20 is disposed at the initial position Po, the sewing target is forward-fed by the feed teeth 10 at the feed amount of the initial value NF.

[0049] The controller 22 switches from forward feed to reverse feed based on the amount of depression from the initial position Po. The controller 22 switches from forward feed to reverse feed when the knee lever 20 moves from the initial position Po to the direction switching position Pi.

[0050] Between the initial position Po and the direction switching position Pi, the controller 22 decreases the forward feed amount as the amount of depression increases. In forward feed, the controller 22 increases the change rate of the feed amount as the amount of depression increases. As the position of the knee lever 20 approaches the direction switching position Pi, the controller 22 rapidly decreases the forward feed amount.

[0051] Between the direction switching position Pi and the maximum position Pm, the controller 22 increases the reverse feed amount as the amount of depression increases. In reverse feed, the controller 22 increases the change rate of the feed amount as the amount of depression increases. As the position of the knee lever 20 approaches the maximum position Pm, the controller 22 rapidly increases the reverse feed amount.

[0052] When the knee lever 20 is disposed at the maximum position Pm, the feed amount of the feed teeth 10 is set to the initial value RF. The initial value RF is set, for example, by operating the operation panel 19. The controller 22 sets the initial value RF based on the input signal from the operation panel 19. When the knee lever 20 is disposed at the maximum position Pm, the sewing target is reverse-fed by the feed teeth 10 at the feed amount of the initial value RF.

[0053] The absolute value of the initial value NF and the absolute value of the initial value RF may be set to the same value or different values. In the present embodiment, the absolute value of the initial value NF and the absolute value of the initial value RF are set to the same value.

[0054] The rate of change of the feed amount during reverse feed is greater than the rate of change of the feed amount during forward feed. The operator can finely adjust the feed amount during forward feed. The operator can increase the feed amount during reverse feed with a slight pushing amount.

[0055] <Sewing method> FIG. 5 is a diagram for explaining the relationship between the pushing amount of the knee lever 20 and the feed amount of the feed dog 10 according to the present embodiment. FIG. 6 is a diagram for explaining the seam formed in the sewing object according to the present embodiment.

[0056] When the feed amount of the feed dog 10 is large, the seam pitch formed in the sewing object is large. When the feed amount of the feed dog 10 is small, the seam pitch formed in the sewing object is small.

[0057] For example, when performing straight sewing (ordinary sewing), the operator operates the knee lever 20 so that the sewing object is fed forward. As shown in FIG. 6, for example, when reinforcing the end of the sewing object, the operator forms a straight sewing seam to the end of the sewing object and then performs backstitching. When performing backstitching, the operator operates the knee lever 20 so that the sewing object is fed backward. Also, so that the last seam of the straight sewing is formed at the target position of the end of the sewing object, the operator reduces the seam pitch at the end stage of the straight sewing. When reducing the seam pitch, the operator operates the knee lever 20 so that the feed amount becomes small.

[0058] When starting to sew the object to be sewn, the object to be sewn is held by the presser 8. When starting straight stitching, the operator operates the pedal 18 so that the sewing machine motor 12 is driven without operating the knee lever 20. By driving the sewing machine motor 12, straight stitching is started. As shown in FIG. 5, in the state Ta where the knee lever 20 is not pushed in, the feed dog 10 feeds the object to be sewn forward at the feed amount of the initial value NF.

[0059] When the stitch of the straight stitch is formed near the end of the object to be sewn, the operator starts operating the knee lever 20 so that the last stitch of the straight stitch is formed at the target position of the end of the object to be sewn. As shown in FIG. 5, in the state Tb where the knee lever 20 is pushed to the right from the initial position Po and has not reached the direction change position Pi, the feed dog 10 feeds the object to be sewn forward at a feed amount smaller than the initial value NF. By reducing the feed amount, the stitch pitch becomes smaller. The operator can gradually reduce the stitch pitch by pushing the knee lever 20 to the right. The operator can finely adjust the stitch pitch by slowly pushing the knee lever 20. As shown in FIG. 6, since the stitch pitch can be finely adjusted, the operator can form the last stitch of the straight stitch at the target position of the end of the object to be sewn.

[0060] After the last stitch of the straight stitch is formed at the target position of the end of the object to be sewn, the operator further pushes the knee lever 20 to the right so that the feed amount becomes 0. As shown in FIG. 5, in the state Tc where the knee lever 20 reaches the direction change position Pi, the feed amount of the feed dog 10 becomes 0.

[0061] After the feed amount becomes 0, the operator further pushes the knee lever 20 to the right so that reverse stitching is started. As shown in FIG. 5, in the state Td where the knee lever 20 passes through the direction change position Pi and reaches the maximum position Pm, the feed dog 10 feeds the object to be sewn backward at the feed amount of the initial value RF.

[0062] In this way, the operator can continuously change from the state Ta in which straight stitching is performed to the state Td in which backstitching is performed through the state Tb in which the stitch pitch in straight stitching is finely adjusted and the state Tc in which the feed amount becomes zero by operating so as to push the knee lever 20 rightward from the initial position Po.

[0063] <Effect> As described above, the sewing machine 1 according to the present embodiment includes a feed dog 10 that feeds a sewing target, a knee lever 20 that is operated so as to be pushed rightward in a predetermined direction (rightward) from the initial position Po by the operator's knee, a lever sensor 21 that detects the pushing amount of the knee lever 20 from the initial position Po, and a controller 22 that outputs a control command for changing the feed amount of the feed dog 10 based on the detection signal of the lever sensor 21.

[0064] According to the present embodiment, the operator can adjust the feed amount of the feed dog 10 by operating so as to push the knee lever 20 rightward only by moving the right knee rightward while sitting on the chair. The operator can adjust the feed amount of the feed dog 10 with good operability.

[0065] The controller 22 makes the feed amount smaller as the pushing amount from the initial position Po is larger. Thereby, after performing straight stitching while feeding the sewing target forward at the feed amount of the initial value NF, the operator can gradually reduce the stitch pitch at the end of the sewing target by gradually pushing the knee lever 20 rightward.

[0066] The controller 22 increases the rate of change of the feed amount as the pushing-in amount from the initial position Po increases. When the knee lever 20 is pushed to the right, the posture of the operator is such that the knees of the left and right legs are separated. That is, when the knee lever 20 is pushed to the right, the posture of the operator is such that both knees are spread apart. A large pushing-in amount from the initial position Po means that the posture of the operator is such that both knees are widely spread. In a posture where both knees are widely spread, it may be difficult for the operator to push the knee lever 20 to the right. In the present embodiment, the rate of change of the feed amount increases as the pushing-in amount from the initial position Po increases. That is, in a range where the pushing-in amount from the initial position Po is large within the rotation range of the knee lever 20, the feed amount changes even when the knee lever 20 is moved slightly. The operator can change the feed amount by simply moving the knee lever 20 even in a posture where both knees are widely spread. The operator can operate the knee lever 20 without discomfort.

[0067] The feed teeth 10 can perform forward feeding that feeds the sewing target forward in the positive direction and reverse feeding that feeds the sewing target backward in the reverse direction. The controller 22 switches from forward feeding to reverse feeding based on the pushing-in amount from the initial position Po. Thereby, the operator can continuously change from the state Ta where straight sewing is performed to the state Td where backstitching is performed through the state Tb where the stitch pitch in straight sewing is finely adjusted and the state Tc where the feed amount becomes 0 by operating the knee lever 20 to push it to the right from the initial position Po.

[0068] In the rotation range of the knee lever 20, the distance between the direction switching position Pi and the maximum position Pm is shorter than the distance between the direction switching position Pi and the initial position Po. The rate of change of the feed amount in reverse feeding is larger than the rate of change of the feed amount in forward feeding. Thereby, the operator can finely adjust the feed amount in forward feeding and can finely adjust the stitch pitch. The operator can increase the feed amount in reverse feeding with a small pushing-in amount.

[0069] [Second Embodiment] The second embodiment will be described. In the following description, components that are the same as or equivalent to those in the above-described embodiment are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0070] FIG. 7 is a diagram for explaining a method of adjusting the feed amount of the feed teeth 10 according to the present embodiment. In the graph shown in FIG. 7, the horizontal axis represents the amount of depression of the knee lever 20 from the initial position Po. The vertical axis represents the feed amount of the feed teeth 10.

[0071] As shown in FIG. 7, the controller 22 decreases the feed amount of the feed teeth 10 as the amount of depression of the knee lever 20 from the initial position Po increases. The feed teeth 10 can perform forward feeding that feeds the sewing target forward in the positive direction and reverse feeding that feeds the sewing target backward in the reverse direction. The controller 22 decreases the forward feed amount as the amount of depression of the knee lever 20 increases between the initial position Po and the direction switching position Pi, and increases the reverse feed amount as the amount of depression of the knee lever 20 increases between the direction switching position Pi and the maximum position Pm. In the rotation range of the knee lever 20, the distance between the direction switching position Pi and the maximum position Pm is shorter than the distance between the direction switching position Pi and the initial position Po.

[0072] In the present embodiment, as shown in FIG. 7, the controller 22 makes the change rate of the feed amount of the feed teeth 10 constant. The controller 22 makes the change rate of the feed amount of the feed teeth 10 constant for each of forward feeding and reverse feeding. That is, the amount of depression of the knee lever 20 from the initial position Po and the feed amount of the feed teeth 10 are in a proportional relationship. The change rate of the reverse feed amount is larger than the change rate of the forward feed amount.

[0073] The operator can adjust the feed amount of the feed teeth 10 by operating to push the knee lever 20 to the right by simply moving the right knee to the right while sitting on the chair. The operator can adjust the feed amount of the feed teeth 10 with good operability.

[0074] [Third Embodiment] The third embodiment will be described. In the following description, components that are the same as or equivalent to those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0075] FIG. 8 is a diagram for explaining a method of adjusting the feed amount of the feed tooth 10 according to the present embodiment. In the graph shown in FIG. 8, the horizontal axis represents the amount of depression of the knee lever 20 from the initial position Po. The vertical axis represents the feed amount of the feed tooth 10.

[0076] In the present embodiment, the controller 22 changes the direction switching position Pi based on an input signal from the operation panel 19 which is an input device. FIGS. 8(A) and 8(B) show an example in which, within the rotation range of the knee lever 20, the distance Wa between the direction switching position Pi and the maximum position Pm is shorter than the distance between the direction switching position Pi and the initial position Po. The distance Wa shown in FIG. 8(A) is shorter than the distance Wa shown in FIG. 8(B). FIG. 8(C) shows an example in which, within the rotation range of the knee lever 20, the distance Wa between the direction switching position Pi and the maximum position Pm is longer than the distance between the direction switching position Pi and the initial position Po.

[0077] In this way, the operator can change the direction switching position Pi within the rotation range of the knee lever 20 and can change the distance Wa by operating the operation panel 19. The operator can change the distance Wa according to, for example, his or her preference.

[0078] [Fourth Embodiment] The fourth embodiment will be described. In the following description, components that are the same as or equivalent to those in the above-described embodiments are denoted by the same reference numerals, and the description of those components will be simplified or omitted.

[0079] In the present embodiment, the operator can operate the knee lever 20 to raise the presser 8. The controller 22 controls the presser motor 14 based on the detection signal from the lever sensor 21 so that the presser 8 rises. The controller 22 outputs an ascending command to raise the presser 8 based on the detection signal of the lever sensor 21.

[0080] FIG. 9 is a diagram for explaining a method of adjusting the feed amount of the feed tooth 10 and a method of raising the presser 8 according to the present embodiment. In the graph shown in FIG. 9, the horizontal axis represents the amount of depression of the knee lever 20 from the initial position Po. The first vertical axis represents the feed amount of the feed tooth 10. The second vertical axis represents the amount of rise of the presser 8.

[0081] Similar to the above-described embodiment, the knee lever 20 is rotatable within a rotation range between the initial position Po and the maximum position Pm. In the rotation range of the knee lever 20, a direction switching position Pi is defined between the initial position Po and the maximum position Pm.

[0082] In the present embodiment, an operation switching position Pt is defined between the initial position Po and the maximum position Pm within the rotation range of the knee lever 20. The operation switching position Pt is defined between the direction switching position Pi and the maximum position Pm within the rotation range of the knee lever 20. The amount of depression of the knee lever 20 from the initial position Po at the operation switching position Pt is the intermediate value St. The intermediate value St is larger than the intermediate value Si. In the rotation range of the knee lever 20, the distance between the direction switching position Pi and the operation switching position Pt is shorter than the distance between the direction switching position Pi and the initial position Po. The difference between the intermediate value Si and the intermediate value St is smaller than the intermediate value Si.

[0083] Similar to the above-described embodiment, the controller 22 switches the feed direction of the feed tooth 10 from forward feed to reverse feed when the knee lever 20 moves from the initial position Po to the direction switching position Pi.

[0084] The controller 22 outputs a raising command for raising the presser 8 to the presser motor 14 when the knee lever 20 moves from the direction switching position Pi to the operation switching position Pt.

[0085] When the knee lever 20 is disposed at the initial position Po, the feed amount of the feed tooth 10 is set to the initial value NF. When the knee lever 20 is disposed at the initial position Po, the amount of rise of the presser 8 is set to 0. That is, when the knee lever 20 is disposed at the initial position Po, the presser 8 presses the sewing target from above.

[0086] Between the initial position Po and the direction change position Pi, the controller 22 decreases the forward feed amount as the pushing amount increases. In forward feed, the controller 22 increases the rate of change of the feed amount as the pushing amount increases. The controller 22 decreases the forward feed amount as the position of the knee lever 20 approaches the direction change position Pi.

[0087] Between the direction change position Pi and the operation change position Pt, the controller 22 increases the reverse feed amount as the pushing amount increases. In reverse feed, the controller 22 increases the rate of change of the feed amount as the pushing amount increases. The controller 22 increases the reverse feed amount as the position of the knee lever 20 approaches the operation change position Pt.

[0088] Between the operation change position Pt and the maximum position Pm, the controller 22 increases the rising amount of the presser 8 as the pushing amount increases. The controller 22 makes the rate of change of the rising amount of the presser 8 constant. That is, the pushing amount of the knee lever 20 from the operation change position Pt and the rising amount of the presser 8 are in a proportional relationship.

[0089] When the knee lever 20 is arranged at the maximum position Pm, the rising amount of the presser 8 is set to the maximum value Lm. The maximum value Lm is set, for example, by operating the operation panel 19. The controller 22 sets the maximum value Lm based on the input signal from the operation panel 19. When the knee lever 20 is arranged at the maximum position Pm, the presser 8 is arranged at the upper end position of the movable range of the presser 8.

[0090] FIG. 10 is a diagram for explaining the relationship between the pushing amount of the knee lever 20, the feed amount of the feed teeth 10, and the operation of the presser 8 according to the present embodiment.

[0091] When starting to sew the object to be sewn, the object to be sewn is held down by the presser 8. When starting straight stitching, the operator operates the pedal 18 so that the sewing machine motor 12 is driven without operating the knee lever 20. By driving the sewing machine motor 12, straight stitching is started. As shown in FIG. 10, in the state Te where the knee lever 20 is not pushed in, the feed dog 10 feeds the object to be sewn forward at the feed amount of the initial value NF.

[0092] When the stitch of the straight stitching is formed near the end of the object to be sewn, the operator starts operating the knee lever 20 so that the last stitch of the straight stitching is formed at the target position of the end of the object to be sewn. When the knee lever 20 is pushed to the right of the initial position Po and has not reached the direction change position Pi, the feed dog 10 feeds the object to be sewn forward at a feed amount smaller than the initial value NF. By reducing the feed amount, the stitch pitch becomes smaller. The operator can gradually reduce the stitch pitch by pushing the knee lever 20 to the right. The operator can finely adjust the stitch pitch by slowly pushing the knee lever 20. Since the stitch pitch can be finely adjusted, the operator can form the last stitch of the straight stitching at the target position of the end of the object to be sewn.

[0093] After the last stitch of the straight stitching is formed at the target position of the end of the object to be sewn, the operator further pushes the knee lever 20 to the right so that the feed amount becomes 0. As shown in FIG. 10, in the state Tf where the knee lever 20 has reached the direction change position Pi, the feed amount of the feed dog 10 becomes 0.

[0094] After the feed amount becomes 0, the operator further pushes the knee lever 20 to the right so that backstitching is started. As shown in FIG. 10, in the state Tg where the knee lever 20 has passed the direction change position Pi and reached the operation change position Pt, the feed dog 10 feeds the object to be sewn backward at the feed amount of the initial value RF.

[0095] After the reverse stitching is completed, the operator releases the operation of the pedal 18 so that the sewing machine motor 12 stops while maintaining the position of the knee lever 20 at the operation switching position Pt. When the sewing machine motor 12 stops, the sewing of the sewing target is completed. After the sewing machine motor 12 stops, the operator pushes the knee lever 20 from the operation switching position Pt to the maximum position Pm so that the presser 8 rises. As shown in FIG. 10, in the state Th where the knee lever 20 has passed through the operation switching position Pt and reached the maximum position Pm, the presser 8 rises to the maximum value Lm. When the presser 8 rises, the pressing of the sewing target by the presser 8 is released.

[0096] In this way, the operator can continuously change from the state Te in which straight stitching is performed to the state in which the stitch pitch in straight stitching is finely adjusted, the state Tf in which the feed amount becomes 0, and the state Tg in which reverse stitching is performed, and then to the state Th in which the presser 8 rises by operating the knee lever 20 so as to push it rightward from the initial position Po.

[0097] As described above, in the present embodiment, when the knee lever 20 is operated, a series of operations of straight stitching, reverse stitching, and raising the presser are continuously performed. Therefore, the operator can perform the adjustment of the feed amount and the raising of the presser with good operability.

[0098] FIG. 11 is a diagram for explaining the rotational load of the knee lever 20 according to the present embodiment. In the rotation range of the knee lever 20, the rotational load of the knee lever 20 between the initial position Po and the operation switching position Pt is different from the rotational load of the knee lever 20 between the operation switching position Pt and the maximum position Pm. In the example shown in FIG. 11, the rotational load of the knee lever 20 between the initial position Po and the operation switching position Pt is lighter than the rotational load of the knee lever 20 between the operation switching position Pt and the maximum position Pm. By changing the rotational load of the knee lever 20 with the operation switching position Pt as a boundary, the operator can recognize that the state has changed from the state in which the feed amount is adjusted to the state in which the presser 8 rises. By changing the rotational load of the knee lever 20 with the operation switching position Pt as a boundary, the operating feeling of the knee lever 20 is improved.

[0099] When the knee lever 20 rotates from the initial position Po to the operation switching position Pt, the biasing force of the torsion spring 20E acts on the knee lever 20. When the knee lever 20 rotates from the operation switching position Pt to the maximum position Pm, in addition to the biasing force of the torsion spring 20E, by applying the biasing force of the second biasing member to the knee lever 20, the rotational load of the knee lever 20 between the operation switching position Pt and the maximum position Pm can be made heavier than the rotational load of the knee lever 20 between the initial position Po and the operation switching position Pt. Examples of the second biasing member include a second torsion spring, a coil spring, and a leaf spring.

[0100] Note that the rotational load of the knee lever 20 between the initial position Po and the operation switching position Pt may be lighter than the rotational load of the knee lever 20 between the operation switching position Pt and the maximum position Pm.

[0101] [Fifth Embodiment] The fifth embodiment will be described. In the following description, components that are the same as or equivalent to those of the above-described embodiment are denoted by the same reference numerals, and the description of those components is simplified or omitted.

[0102] In the present embodiment, the controller 22 switches the feed direction of the feed teeth 10 from forward feed to reverse feed based on the amount of depression of the knee lever 20 from the initial position Po during the driving of the sewing machine motor 12. The controller 22 outputs an elevation command to raise the presser 8 based on the amount of depression of the knee lever 20 from the initial position Po during the stop of the sewing machine motor 12.

[0103] When a drive command is output from the controller 22 to the sewing machine motor 12, the sewing machine motor 12 is driven. When a drive command is not output from the controller 22, the sewing machine motor 12 stops. The fact that the sewing machine motor 12 is driving means that the sewing machine 1 is sewing the sewing target. The fact that the sewing machine motor 12 is stopped means that the sewing machine 1 is stopped.

[0104] When the controller 22 outputs a drive command to drive the sewing machine motor 12, it switches the feed direction of the feed teeth 10 from forward feed to reverse feed based on the detection signal from the lever sensor 21. That is, during the driving of the sewing machine motor 12, as described in the above-described first embodiment, second embodiment, and third embodiment, the controller 22 switches the feed direction of the feed teeth 10 from forward feed to reverse feed based on the amount of depression of the knee lever 20.

[0105] While the sewing machine motor 12 is driving, the presser 8 does not rise. While the sewing machine motor 12 is driving, the presser motor 14 does not drive. While the sewing machine motor 12 is driving, the amount of rise of the presser 8 is 0, and the presser 8 continues to press the sewing object.

[0106] FIG. 12 is a diagram for explaining the method of raising the presser 8 according to the present embodiment. In the graph shown in FIG. 12, the horizontal axis represents the amount of depression of the knee lever 20 from the initial position Po. The vertical axis represents the amount of rise of the presser 8. Similar to the above-described embodiment, the knee lever 20 is rotatable within a rotation range between the initial position Po and the maximum position Pm. The operator can operate the knee lever 20 to raise the presser 8.

[0107] While the sewing machine motor 12 is stopped, the controller 22 controls the presser motor 14 so that the presser 8 rises based on the detection signal from the lever sensor 21. The controller 22 outputs a raise command to raise the presser 8 based on the detection signal of the lever sensor 21.

[0108] When the sewing machine motor 12 is stopped and the knee lever 20 is disposed at the initial position Po, the lifting amount of the presser 8 is 0. When the sewing machine motor 12 is stopped, the controller 22 increases the lifting amount of the presser 8 as the pushing amount is larger between the initial position Po and the maximum position Pm. The controller 22 makes the change rate of the lifting amount of the presser 8 constant. That is, the pushing amount of the knee lever 20 from the initial position Po and the lifting amount of the presser 8 are in a proportional relationship. When the knee lever 20 is disposed at the maximum position Pm, the lifting amount of the presser 8 is set to the maximum value Lm.

[0109] Note that when the sewing machine motor 12 is stopped, the feed motor 13 operates so that the feed amount of the feed teeth 10 becomes the initial value NF. Thereby, when switching from the state where the sewing machine motor 12 is stopped to the driving state, the feed teeth 10 can feed the sewing target forward by the initial value NF.

[0110] Note that when switching from the state where the sewing machine motor 12 is driven to the stopped state while the knee lever 20 is being pushed, the feed motor 13 operates so that the feed amount of the feed teeth 10 becomes the initial value NF from the feed amount corresponding to the pushing amount of the knee lever 20, and the presser motor 14 operates so that the presser 8 rises by the lifting amount corresponding to the pushing amount of the knee lever 20.

[0111] The state where the knee lever 20 is being pushed while the sewing machine motor 12 is driven is a state where the feed amount of the feed teeth 10 is made smaller and the stitch pitch is finely adjusted to be smaller. When switching to the state where the sewing machine motor 12 stops while the stitch pitch is finely adjusted, the operator can immediately raise the presser 8 by pushing the knee lever 20.

[0112] Note that when switching from the state where the sewing machine motor 12 is stopped to the driving state while the knee lever 20 is being pushed, the feed motor 13 operates so that the feed amount of the feed teeth 10 becomes the initial value NF, and the presser motor 14 operates so that the lifting amount of the presser 8 becomes 0.

[0113] As described above, in the present embodiment, when the sewing machine motor 12 changes from the driven state to the stopped state, the operator can immediately raise the presser 8 by pushing in the knee lever 20. Further, in the present embodiment, since the rotatable range of the knee lever 20 when raising the presser 8 is increased, the operator can finely adjust the amount of rise of the presser 8.

Explanation of Signs

[0114] 1... Sewing machine, 2... Sewing machine table, 3... Sewing machine frame, 4... Sewing machine needle, 5... Needle bar, 6... Balance, 7... Needle plate, 8... Presser, 9... Thread tension, 10... Feed teeth, 11... Bobbin, 12... Sewing machine motor, 13... Feed motor, 14... Presser motor, 15... Sewing machine power transmission mechanism, 16... Feed amount adjustment mechanism, 17... Presser raising mechanism, 18... Pedal, 19... Operation panel, 20... Knee lever, 20A... Pad, 20B... Rod, 20C... Bracket, 20D... Support shaft, 20E... Torsion spring, 21... Lever sensor, 22... Controller, Lm... Maximum value, Pi... Direction switching position, Pm... Maximum position, Po... Initial position, Pt... Operation switching position, Si... Intermediate value, Sm... Maximum value, St... Intermediate value.

Claims

1. A feed dog for feeding the sewing object; a knee lever that is operated by an operator's knee so as to be pushed in a predetermined direction from an initial position; a lever sensor for detecting an amount of depression of the knee lever from the initial position; and a controller that outputs a control command to change a feed amount of the feed dog based on a detection signal of the lever sensor. sewing machine.

2. The controller reduces the feed amount as the pushing amount increases.

2. The sewing machine according to claim 1.

3. The controller increases a rate of change of the feed amount as the pushing amount increases.

3. The sewing machine according to claim 2.

4. The controller keeps the rate of change of the feed rate constant.

3. The sewing machine according to claim 2.

5. The feed dog can perform forward feed for feeding the sewing object in a forward direction and reverse feed for feeding the sewing object in a reverse direction, The controller switches from the forward feed to the reverse feed based on the amount of depression.

2. The sewing machine according to claim 1.

6. The knee lever is rotatable within a rotation range between the initial position and a maximum position, a direction switching position is defined between the initial position and the maximum position in the rotation range, The controller switches from the forward feed to the reverse feed when the knee lever moves from the initial position to the direction switching position.

6. The sewing machine according to claim 5.

7. the controller reduces the forward feed amount as the pushing amount increases between the initial position and the direction switching position, and increases the reverse feed amount as the pushing amount increases between the direction switching position and the maximum position.

7. The sewing machine according to claim 6.

8. In the rotation range, a distance between the direction switching position and the maximum position is shorter than a distance between the direction switching position and the initial position.

8. The sewing machine according to claim 7.

9. a rate of change in the reverse feed amount is greater than a rate of change in the forward feed amount; 9. The sewing machine according to claim 8.

10. the controller increases a rate of change of the feed amount as the pushing amount increases in each of the forward feed and the reverse feed.

10. The sewing machine according to claim 9.

11. The controller keeps the rate of change of the feed amount constant in each of the forward feed and the reverse feed.

10. The sewing machine according to claim 9.

12. An input device is provided, The controller changes the direction switching position based on an input signal from the input device.

7. The sewing machine according to claim 6.

13. A presser that presses the sewing object is provided, The knee lever is rotatable within a rotation range between the initial position and a maximum position, An operation switching position is defined between the initial position and the maximum position, The controller: When the knee lever moves from the initial position to the motion switching position, a lift command is output to lift the presser foot.

4. The sewing machine according to claim 3.

14. In the rotation range, a rotation load of the knee lever between the initial position and the motion switching position is different from a rotation load of the knee lever between the motion switching position and the maximum position.

14. The sewing machine according to claim 13.

15. a needle bar for holding a sewing needle; a sewing machine motor that operates each of the needle bar and the feed dog; A presser that presses the sewing object, The knee lever is rotatable within a rotation range between the initial position and a maximum position, The controller: while the sewing machine motor is being driven, switching from the forward feed to the reverse feed based on the amount of depression; outputting a lift command for lifting the presser foot based on the pressing amount while the sewing machine motor is stopped; 6. The sewing machine according to claim 5.

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