Sewing machine

Abstract

The invention provides a sewing machine capable of adjusting feeding amount with good operability. The sewing machine according to the present invention comprises: feeding teeth for conveying a sewing object; a knee lever which is operated by the knee of the operator so as to be pressed in from an initial position in a prescribed direction; a lever sensor that detects the amount of press-in of the knee lever from the initial position; and a controller that outputs a control command for changing the feeding amount of the feeding teeth on the basis of a detection signal from the lever sensor.

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 capable of adjusting the feed amount of a feed tooth as disclosed in Patent Document 1. Also, there is known a sewing machine including a push-up device for raising a presser foot as disclosed in Patent Document 2. Also, there is known a sewing machine including a knee lever as disclosed in Patent Document 3.

[0003] [Prior art literature] [Patent Document] [Patent Document 1] Japanese Patent Application Publication No. 2019-055108; [Patent Document 2] Japanese Patent Publication No. 2011-092523; [Patent document 3] Japanese Patent Utility Model Publication No. 39-24853. Summary of the invention

[0004] [Problems to be solved by the invention] An object of the technology disclosed in this specification is to provide a sewing machine capable of adjusting a feed amount with good operability.

[0005] [Technical means to solve the problem] The present specification discloses a sewing machine. The sewing machine comprises: a feed tooth for conveying a sewing object; a knee lever operated by an operator's knee in a manner of being pressed in from an initial position to a predetermined direction; a lever sensor for detecting the amount of the knee lever pressed in from the initial position; and a controller for outputting a control instruction for changing the feed amount of the feed tooth based on a detection signal of the lever sensor.

[0006] [Effects of the Invention] According to the technology disclosed in this specification, a sewing machine capable of adjusting the feed amount with good operability is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a perspective view showing a sewing machine according to a first embodiment; Figure 2 is a block diagram showing a sewing machine according to a first embodiment; Figure 3 is a diagram showing a knee lever according to a first embodiment; Figure 4 It is a figure used to explain the method of adjusting the feed amount of the feed tooth of the first embodiment; Figure 5 It is a diagram for explaining the relationship between the amount of pressing of the knee lever and the amount of feeding of the feed tooth in the first embodiment; Figure 6 It is a figure used to explain the stitches formed in the sewing object of the first embodiment; Figure 7 It is a figure used to explain the method of adjusting the feed amount of the feed tooth of the second embodiment; Figure 8 (A) to (C) are diagrams for explaining a method for adjusting a feed amount of a feed tooth according to a third embodiment; Fig. 9 It is a diagram for explaining a method for adjusting a feed amount of a feed tooth and a method for raising a presser foot according to a fourth embodiment; Fig.10 It is a diagram for explaining the relationship between the pressing amount of the knee lever, the feeding amount of the feed tooth and the action of the presser foot in the fourth embodiment; Fig.11 is a diagram for explaining the rotation load of the knee lever according to the fourth embodiment; Fig.12 It is a figure for demonstrating the method of raising the presser foot in 5th embodiment.

[0008] Explanation of symbols: 1. Sewing machine 2: Sewing machine table 3: Sewing machine frame 4: Sewing machine needle 5: Needle bar 6: Thread take-up lever 7: Needle plate 8: Presser foot 9: Line regulator 10: Feeding teeth 11: Shuttle 12: Sewing machine motor 13: Conveying motor 14: Presser foot motor 15: Sewing machine power transmission mechanism 16: Feeding amount adjustment mechanism 17: Push-up mechanism 18: Pedal 19: Operation panel 20: Knee Pole 20A: Pad 20B: Rod 20C: Bracket 20D: Support shaft 20E: Torsion spring 21: Rod sensor 22: Controller Lm, Sm: Maximum Pi: Direction switching position Pm: Maximum position Po: initial position Pt: Action switching position Si, St: Intermediate value DETAILED DESCRIPTION Hereinafter, the embodiment will be described with reference to the drawings. In the embodiment, the terms left, right, front, rear, top, and bottom are used to describe the positional relationship of each part. These terms indicate relative positions or directions with respect to the center of the sewing machine 1 as a reference.

[0009] [First embodiment] A first embodiment will be described.

[0010] <Sewing Machine> Figure 1 It is a perspective view showing the sewing machine 1 according to the present embodiment. Figure 2 1 is a block diagram showing a 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 lockstitch sewing machine.

[0011] The sewing machine 1 includes: a sewing machine frame 3, a needle bar 5, a thread take-up lever 6, a needle plate 7, a presser foot 8, a thread regulator 9, a feed tooth 10, a shuttle 11, a sewing machine motor 12, a conveying motor 13, a presser foot motor 14, a sewing machine power transmission mechanism 15, a feed amount adjustment mechanism 16, a push-up 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 arranged on the upper surface of the sewing machine table 2. The sewing machine table 2 is supported by table legs. A chair is arranged at 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 moves back and forth in the up-down direction. The needle bar 5 is supported by the sewing machine frame 3. The sewing machine needle 4 includes a threading hole for the upper thread to pass through. The sewing machine needle 4 holds the upper thread with the inner surface of the threading hole. As the needle bar 5 moves back and forth in the up-down direction, the sewing machine needle 4 moves back and forth in the up-down direction while holding the upper thread.

[0014] The thread take-up lever 6 supplies the upper thread to the sewing machine needle 4. The thread take-up lever 6 moves back and forth in the up-down direction. The thread take-up lever 6 is supported by the sewing machine frame 3. The thread take-up lever 6 moves back and forth in the up-down direction while holding the upper thread. The thread take-up lever 6 includes a holding hole for the upper thread to pass through. The thread take-up lever 6 holds the upper thread with the inner surface of the holding hole. The thread take-up lever 6 reciprocates in the up-down direction to wind out the upper thread used for sewing the sewing object or pull up the upper thread.

[0015] The needle plate 7 supports the sewing object from below. The needle plate 7 supports the sewing object below the needle bar 5. The needle plate 7 is arranged below the needle bar 5. The sewing machine needle 4 held by the needle bar 5 faces the needle plate 7. The needle plate 7 includes a needle hole through which the sewing machine needle 4 can pass. The sewing machine needle 4 that passes through the sewing object supported by the needle plate 7 passes through the needle hole.

[0016] The presser foot 8 pushes the sewing object supported by the needle plate 7 from above. The presser foot 8 is arranged at least a part of the periphery of the sewing machine needle 4. The presser foot 8 is supported by the sewing machine frame 3. The presser foot 8 can move in the up-down direction. A presser foot spring is arranged around the upper end of the presser foot 8. The presser foot spring generates an elastic force that moves the presser foot 8 downward. The presser foot 8 is pressed against the sewing object from above by the elastic force generated by the presser foot spring.

[0017] The thread regulator 9 applies tension to the upper thread supplied to the sewing machine needle 4 between the thread take-up lever 6 and the needle bar 5. The thread regulator 9 is supported by the sewing machine frame 3.

[0018] The feed tooth 10 works in a manner of feeding the sewing object supported by the needle plate 7 forward or backward. The feed tooth 10 feeds the sewing object by moving along a predetermined conveying track. The feed tooth 10 is arranged below the needle plate 7. The feed tooth 10 moves along the conveying track and enters and exits from the opening provided in the needle plate 7. When feeding the sewing object, at least a part of the feed tooth 10 protrudes upward from the upper surface of the needle plate 7 through the opening provided in the needle plate 7.

[0019] The shuttle 11 supplies the lower thread to the sewing object. The shuttle 11 is arranged below the feed dog 10. The shuttle 11 can rotate.

[0020] The sewing machine motor 12 generates power for operating the needle bar 5, the feed tooth 10, and the shuttle 11, respectively. The sewing machine motor 12 generates power for moving the needle bar 5 back and forth in the up and down directions. The sewing machine motor 12 generates power for rotating the shuttle 11. The sewing machine motor 12 generates power for moving the feed tooth 10 along the conveying track. The sewing machine motor 12 includes a servo motor. The sewing machine motor 12 is supported by the right part of the sewing machine frame 3.

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

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

[0023] The sewing machine power transmission mechanism 15 operates the needle bar 5, the feed tooth 10, and the shuttle 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 the needle bar 5, the feed tooth 10, and the shuttle 11, respectively.

[0024] The needle bar 5 and the sewing needle 4 held by the needle bar 5 move back and forth in the up-down direction based on the power generated by the sewing machine motor 12. The shuttle 11 rotates in synchronization with the up-down movement of the needle bar 5 to supply the lower thread to the sewing object. The feed tooth 10 swings in the front-to-back direction and the up-to-down direction in synchronization with the up-to-down movement of the needle bar 5 to feed the sewing object forward or backward. The sewing machine 1 sews the sewing object by the cooperative action of the sewing needle 4 held by the needle bar 5 and the shuttle 11.

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

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

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

[0029] The knee lever 20 is operated by the operator. The knee lever 20 is supported by the lower part of the sewing machine table 2 in a rotatable manner. The knee lever 20 can rotate within a prescribed rotation range. The knee lever 20 rotates substantially to the right or left. The operator operates the knee lever 20 with his knee. For example, the operator operates the knee lever 20 by pressing the knee lever 20 to the right with the knee of his right leg.

[0030] In this embodiment, the operator can operate the knee lever 20 to change the feed amount of the feed dog 10. The operator can operate the knee lever 20 to switch the feed direction of the feed dog 10. The feed direction of the feed dog 10 is forward or backward.

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

[0032] The controller 22 includes a processor such as a central processing unit (CPU), a memory such as a read only memory (ROM) or a random access memory (RAM), and an input / output interface including an input / output circuit capable of inputting and outputting signals and data. The controller 22 controls the sewing machine motor 12, the conveying motor 13, and the presser foot motor 14, respectively. 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. If the pedal 18 is operated in such a manner that the front portion of the pedal 18 moves downward, the controller 22 drives the sewing machine motor 12. The sewing machine motor 12 is driven to sew the sewing object. When the sewing object is sewn, the presser foot 8 presses the sewing object from above. If the pedal 18 is operated in such a manner that the rear portion of the pedal 18 moves downward, the controller 22 stops the sewing machine motor 12.

[0034] The controller 22 controls the conveying motor 13 in such a manner that the feed amount of the feed tooth 10 changes based on the detection signal of the rod sensor 21. The controller 22 outputs a control command to change the feed amount of the feed tooth 10 to the conveying motor 13 based on the detection signal of the rod sensor 21. The controller 22 controls the conveying motor 13 in such a manner that the conveying direction of the feed tooth 10 is switched based on the detection signal of the rod sensor 21. The controller 22 outputs a control command to switch the conveying direction of the feed tooth 10 to the conveying motor 13 based on the detection signal of the rod sensor 21.

[0035] <Knee bar> Figure 3 2 is a diagram showing a knee lever 20 of 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 for the operator's knee to contact. 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 portion of the sewing machine table 2. The support shaft 20D is supported by the bracket 20C in a rotatable manner. The upper end of the rod 20B is fixed to the support shaft 20D. The support shaft 20D supports the pad 20A in a rotatable manner via the rod 20B. The torsion spring 20E is arranged around the support shaft 20D. At least a portion of the torsion spring 20E is connected to the bracket 20C.

[0037] The operator operates the knee lever 20 to push the knee lever 20 to the right, for example, with the right knee abutting against the pad 20A. The knee lever 20 is rotated to the right by the operator's pushing action of the knee lever 20.

[0038] The knee lever 20 can rotate within a predetermined rotation range. The knee lever 20 is arranged at an initial position Po when not operated by the operator. The initial position Po is the left end of the rotation range of the knee lever 20. The knee lever 20 is operated by the operator's knee so as to be pushed in to the right from the initial position Po.

[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 an urging force that pushes the knee lever 20 to the left. When the knee lever 20 is not operated by the operator, the knee lever 20 is arranged at the initial position Po by the urging force of the torsion spring 20E. In addition, a stopper, not shown in the figure, is provided to maintain the position of the knee lever 20 at the initial position Po when the knee lever 20 is not operated by the operator. When the feed amount of the feed tooth 10 is changed, the operator resists the urging force of the torsion spring 20E and performs a pressing action to press the knee lever 20 to the right.

[0040] <Adjustment method> Figure 4 1 is a diagram for explaining a method for adjusting the feed amount of the feed tooth 10 according to the present embodiment. Figure 4 In the graph shown, the horizontal axis represents the amount of the knee lever 20 pushed in from the initial position Po, and the vertical axis represents the feed amount of the feed dog 10 .

[0041] The knee lever 20 can rotate within a rotation range between an initial position Po and a 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 pressure of the knee lever 20 at the initial position Po is 0. The amount of pressure of the knee lever 20 at the maximum position Pm from the initial position Po is the maximum value Sm.

[0042] In addition, within the rotation range of the knee lever 20, a direction switching position Pi is specified between the initial position Po and the maximum position Pm. The direction switching position Pi is the middle part of the rotation range of the knee lever 20. The amount of the knee lever 20 pressed from the initial position Po at the direction switching position Pi is the intermediate value Si. Within 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] Feeding tooth 10 sends the sewing object forward or backward. In the following description, the front is appropriately called the positive direction, and the rear is appropriately called the reverse direction. In addition, sending the sewing object forward is appropriately called the forward conveying, and sending the sewing object backward is appropriately called the reverse conveying.

[0044] The feed dog 10 can perform forward conveyance of conveying the sewing object in the forward direction and reverse conveyance of conveying the sewing object in the reverse direction.

[0045] exist Figure 4 In the curve graph shown, when the feed amount is a positive value greater than 0, it means a state of forward conveyance where the sewing object is conveyed forward. When the feed amount is a negative value less than 0, it means a state of reverse conveyance where the sewing object is conveyed backward. When the feed amount is 0, it means a state where the sewing object is not conveyed.

[0046] like Figure 4 As shown, the controller 22 reduces the feeding amount of the feed tooth 10 as the amount of the knee lever 20 is pressed in from the initial position Po based on the detection signal of the lever sensor 21. The controller 22 increases the rate of change of the feeding amount of the feed tooth 10 as the amount of the knee lever 20 is pressed in from the initial position Po based on the detection signal of the lever sensor 21.

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

[0048] When the knee lever 20 is arranged at the initial position Po, the feed amount of the feed dog 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 an input signal from the operation panel 19. When the knee lever 20 is arranged at the initial position Po, the sewing object is forwardly fed by the feed dog 10 at the feed amount of the initial value NF.

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

[0050] The controller 22 reduces the feed amount of the forward conveying more when the amount of the push-in is greater between the initial position Po and the direction switching position Pi. The controller 22 increases the rate of change of the feed amount more when the amount of the push-in is greater during the forward conveying. The closer the position of the knee lever 20 is to the direction switching position Pi, the more rapidly the controller 22 reduces the feed amount of the forward conveying.

[0051] The controller 22 increases the reverse feed amount as the amount of push-in increases between the direction switching position Pi and the maximum position Pm. The controller 22 increases the rate of change of the feed amount as the amount of push-in increases during reverse feed. The closer the position of the knee lever 20 is to the maximum position Pm, the more rapidly the controller 22 increases the reverse feed amount.

[0052] When the knee lever 20 is arranged at the maximum position Pm, the feed amount of the feed tooth 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 an input signal from the operation panel 19. When the knee lever 20 is arranged at the maximum position Pm, the sewing object is reversely fed by the feed tooth 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 in the reverse direction is greater than that in the forward direction. The operator can fine-tune the feed amount in the forward direction. The operator can increase the feed amount in the reverse direction by a small amount of pressing.

[0055] <Sewing method> Figure 5 This is a diagram for explaining the relationship between the push-in amount of the knee lever 20 and the feed amount of the feed dog 10 in this embodiment. Figure 6 It is a figure for demonstrating the stitch formed in the sewing object of this embodiment.

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

[0057] For example, when performing straight sewing (general sewing), the operator operates the knee lever 20 in a manner of forwardly conveying the sewing object. Figure 6 As shown, for example, in the case of reinforcing the end of the sewing object, the operator performs reverse stitching after forming the stitches of the straight stitch to the end of the sewing object. In the case of performing reverse stitching, the operator operates the knee lever 20 in a manner of feeding the sewing object in the reverse direction. In addition, the operator reduces the stitch spacing at the end of the straight stitch so that the last stitch of the straight stitch is formed at the target position of the end of the sewing object. In the case of reducing the stitch spacing, the operator operates the knee lever 20 in a manner of reducing the feeding amount.

[0058] When starting to sew the sewing object, the sewing object is pushed by the presser foot 8. When starting to sew straight, the operator operates the pedal 18 to drive the sewing machine motor 12 without operating the knee lever 20. Straight sewing is started by driving the sewing machine motor 12. Figure 5 As shown, in the state Ta where the knee lever 20 is not pressed in, the feed dog 10 forwardly feeds the sewing object at a feed amount of the initial value NF.

[0059] When the stitches of the straight seam are formed to the vicinity of the end of the sewing object, the operator starts the operation of the knee lever 20 so as to form the last stitch of the straight seam at the target position of the end of the sewing object. Figure 5 As shown, when the knee lever 20 is pressed to the right of the initial position Po and has not reached the direction switching position Pi, the feed tooth 10 forwardly feeds the sewing object at a feed amount less than the initial value NF. As the feed amount decreases, the stitch spacing decreases. The operator can gradually reduce the stitch spacing by pressing the knee lever 20 to the right. The operator can fine-tune the stitch spacing by slowly pressing the knee lever 20. Figure 6 As shown, since the stitch pitch can be finely adjusted, the operator can form the last stitch of the straight seam at the target position of the end of the sewing object.

[0060] After the last stitch of the straight seam is formed at the target position at the end of the sewing object, the operator presses the knee lever 20 further to the right to make the feed amount zero. Figure 5 As shown, in the state Tc where the knee lever 20 reaches the direction switching position Pi, the feed amount of the feed dog 10 becomes zero.

[0061] After the feed amount becomes 0, the operator pushes the knee lever 20 further to the right to start backstitching. Figure 5 As shown, in the state Td where the knee lever 20 passes through the direction switching position Pi and reaches the maximum position Pm, the feed dog 10 reversely conveys the sewing object at a feed amount of the initial value RF.

[0062] As described above, the operator can press the knee rod 20 to the right from the initial position Po to continuously change from the state Ta of implementing straight stitching, through the state Tb of fine-tuning the stitch spacing in the straight stitching and the state Tc of 0 feed amount, to the state Td of implementing reverse stitching.

[0063] <Effect> As described above, the sewing machine 1 of the present embodiment includes: a feed tooth 10 for conveying a sewing object; a knee lever 20, which is operated by the operator's knee in a manner of being pressed in from an initial position Po to the right as a prescribed direction; a lever sensor 21, which detects the amount of the knee lever 20 pressed in from the initial position Po; and a controller 22, which outputs a control instruction for changing the feed amount of the feed tooth 10 based on the detection signal of the lever sensor 21.

[0064] According to this embodiment, the operator can adjust the feed amount of the feed dog 10 by simply moving the right knee to the right while sitting on the chair, thereby pressing the knee lever 20 to the right. The operator can adjust the feed amount of the feed dog 10 with good operability.

[0065] The greater the amount of pressing from the initial position Po, the more the controller 22 reduces the feed amount. Thus, the operator can gradually reduce the stitch spacing at the end of the sewing object by gradually pressing the knee lever 20 to the right after performing straight sewing while forward feeding the sewing object at the feed amount of the initial value NF.

[0066] The larger the amount of pressing from the initial position Po, the more the controller 22 increases the rate of change of the feed amount. The posture of the operator when pressing the knee lever 20 to the right becomes a posture of separating the knee of the left leg from the knee of the right leg. That is, the posture of the operator when pressing the knee lever 20 to the right becomes a posture of opening both knees. The large amount of pressing from the initial position Po means that the posture of the operator is a posture of opening both knees widely. In the posture of opening both knees widely, there is a possibility that it is difficult for the operator to press the knee lever 20 to the right. In this embodiment, the larger the amount of pressing from the initial position Po, the larger the rate of change of the feed amount. That is, within the range of the rotation range of the knee lever 20 where the amount of pressing from the initial position Po is large, the feed amount changes by an amount that causes the knee lever 20 to move slightly. Even in the posture of opening both knees widely, the operator can change the feed amount by an amount that causes the knee lever 20 to move slightly. The operator can operate the knee lever 20 without discomfort.

[0067] The feed tooth 10 can implement forward conveyance of the sewing object to the front as the positive direction, and reverse conveyance of the sewing object to the rear as the reverse direction. The controller 22 switches from forward conveyance to reverse conveyance based on the amount of pressing from the initial position Po. Thus, the operator can continuously change from the state Ta of implementing straight stitching, through the state Tb of finely adjusting the stitch spacing in the straight stitching and the state Tc of the feed amount becoming 0, to the state Td of implementing reverse stitching by operating in a manner of pressing the knee lever 20 to the right from the initial position Po.

[0068] Within 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 of the reverse conveying is greater than the rate of change of the feed amount of the forward conveying. Thus, the operator can fine-tune the feed amount of the forward conveying and can fine-tune the stitch pitch. The operator can increase the feed amount of the reverse conveying by a small amount of pressing.

[0069] [Second embodiment] In the following description, the same reference numerals are used for the same or equivalent components as those in the above-described embodiment, and the description of the components is simplified or omitted.

[0070] Figure 7 1 is a diagram for explaining a method for adjusting the feed amount of the feed tooth 10 according to the present embodiment. Figure 7 In the graph shown, the horizontal axis represents the amount of the knee lever 20 pushed in from the initial position Po, and the vertical axis represents the feed amount of the feed dog 10 .

[0071] like Figure 7 As shown, the greater the amount of the knee lever 20 is pressed in from the initial position Po, the more the controller 22 reduces the feed amount of the feed tooth 10. The feed tooth 10 can implement forward conveying of the sewing object to the front as the positive direction, and reverse conveying of the sewing object to the rear as the reverse direction. Between the initial position Po and the direction switching position Pi, the greater the amount of the knee lever 20 is pressed in, the more the controller 22 reduces the feed amount of the forward conveying, and between the direction switching position Pi and the maximum position Pm, the greater the amount of the knee lever 20 is pressed in, the more the controller 22 increases the feed amount of the reverse conveying. Within 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 this embodiment, if Figure 7As shown, the controller 22 sets the change rate of the feed amount of the feed tooth 10 to be constant. In each of the forward conveying and the reverse conveying, the controller 22 sets the change rate of the feed amount of the feed tooth 10 to be constant. That is, the amount of the knee lever 20 pressed from the initial position Po is proportional to the feed amount of the feed tooth 10. The change rate of the feed amount in the reverse conveying is greater than the change rate of the feed amount in the forward conveying.

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

[0074] [Third Embodiment] In the following description, the same reference numerals are used to denote components that are the same as or equivalent to those in the above-described embodiment, and descriptions of the components are simplified or omitted.

[0075] Figure 8 (A) to (C) are diagrams for explaining a method for adjusting the feed amount of the feed tooth 10 according to the present embodiment. Figure 8 In the graphs shown in (A) to (C) of FIG. 1 , the horizontal axis represents the amount of the knee lever 20 pushed in from the initial position Po, and the vertical axis represents the feed amount of the feed dog 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 as an input device. Figure 8 (A) and (B) show examples in which 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 within the rotation range of the knee lever 20 . Figure 8 The distance Wa shown in (A) is shorter than Figure 8 The distance Wa is shown in (B). Figure 8 (C) shows an example in which 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 within the rotation range of the knee lever 20 .

[0077] As described above, the operator can change the distance Wa by changing the direction switching position Pi within the rotation range of the knee lever 20 by operating the operation panel 19. The operator can change the distance Wa according to his / her own preference, for example.

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

[0079] In this embodiment, the operator can operate the knee lever 20 to raise the presser foot 8. The controller 22 controls the presser foot motor 14 to raise the presser foot 8 based on the detection signal from the lever sensor 21. The controller 22 outputs a raising command to raise the presser foot 8 based on the detection signal from the lever sensor 21.

[0080] Fig. 9 1 is a diagram for explaining a method for adjusting the feed amount of the feed tooth 10 and a method for raising the presser foot 8 according to the present embodiment. Fig. 9 In the graph shown, the horizontal axis represents the amount of the knee lever 20 pressed in from the initial position Po, the first vertical axis represents the amount of feed by the feed tooth 10, and the second vertical axis represents the amount of lift of the presser foot 8.

[0081] As in the above embodiment, the knee lever 20 can rotate within a rotation range between the initial position Po and the maximum position Pm. Within 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, within the rotation range of the knee lever 20, the action switching position Pt is specified between the initial position Po and the maximum position Pm. The action switching position Pt is specified between the direction switching position Pi and the maximum position Pm within the rotation range of the knee lever 20. The amount of the knee lever 20 pressed in from the initial position Po at the action switching position Pt is the intermediate value St. The intermediate value St is greater than the intermediate value Si. Within the rotation range of the knee lever 20, the distance between the direction switching position Pi and the action 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, when the knee lever 20 moves from the initial position Po to the direction switching position Pi, the controller 22 switches the conveying direction of the feed dog 10 from the forward conveying direction to the reverse conveying direction.

[0084] When the knee lever 20 moves from the direction switching position Pi to the operation switching position Pt, the controller 22 outputs a lifting command to the presser foot motor 14 to lift the presser foot 8 .

[0085] When the knee lever 20 is arranged at the initial position Po, the feed amount of the feed dog 10 is set to the initial value NF. When the knee lever 20 is arranged at the initial position Po, the lifting amount of the presser foot 8 is set to 0. That is, when the knee lever 20 is arranged at the initial position Po, the presser foot 8 presses the sewing object from above.

[0086] Between the initial position Po and the direction switching position Pi, the larger the amount of push-in, the more the controller 22 reduces the feed amount of the forward conveying. In the forward conveying, the larger the amount of push-in, the more the controller 22 increases the rate of change of the feed amount. The closer the position of the knee lever 20 is to the direction switching position Pi, the more the controller 22 reduces the feed amount of the forward conveying.

[0087] Between the direction switching position Pi and the action switching position Pt, the larger the amount of push-in, the more the controller 22 increases the feed amount of the reverse conveying. During the reverse conveying, the larger the amount of push-in, the more the controller 22 increases the rate of change of the feed amount. The closer the position of the knee lever 20 is to the action switching position Pt, the more the controller 22 increases the feed amount of the reverse conveying.

[0088] Between the action switching position Pt and the maximum position Pm, the larger the amount of pressing, the more the controller 22 increases the amount of lifting of the presser foot 8. The controller 22 sets the rate of change of the amount of lifting of the presser foot 8 to be constant. That is, the amount of pressing of the knee lever 20 from the action switching position Pt is proportional to the amount of lifting of the presser foot 8.

[0089] When the knee lever 20 is arranged at the maximum position Pm, the lifting amount of the presser foot 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 foot 8 is arranged at the upper end position of the movable range of the presser foot 8.

[0090] Fig.10 This is a diagram for explaining the relationship between the pushing amount of the knee lever 20, the feeding amount of the feed dog 10, and the movement of the presser foot 8 in this embodiment.

[0091] When starting to sew the sewing object, the sewing object is pushed by the presser foot 8. When starting to sew straight, the operator operates the pedal 18 to drive the sewing machine motor 12 without operating the knee lever 20. Straight sewing is started by driving the sewing machine motor 12. Fig.10 As shown, in the state Te where the knee lever 20 is not pressed in, the feed dog 10 forwardly feeds the sewing object at a feed amount of the initial value NF.

[0092] When the stitches of the straight seam are formed to the vicinity of the end of the sewing object, the operator starts to operate the knee lever 20 so as to form the last stitch of the straight seam at the target position at the end of the sewing object. When the knee lever 20 is pressed to the right of the initial position Po and has not reached the direction switching position Pi, the feed tooth 10 forwardly conveys the sewing object at a feed amount less than the value of the initial value NF. As the feed amount decreases, the stitch spacing decreases. The operator can gradually reduce the stitch spacing by pressing the knee lever 20 to the right. The operator can fine-tune the stitch spacing by slowly pressing the knee lever 20. Since the stitch spacing can be fine-tuned, the operator can form the last stitch of the straight seam at the target position at the end of the sewing object.

[0093] After the last stitch of the straight seam is formed at the target position at the end of the sewing object, the operator presses the knee lever 20 further to the right to make the feed amount zero. Fig.10 As shown, in the state Tf where the knee lever 20 reaches the direction switching position Pi, the feed amount of the feed dog 10 becomes zero.

[0094] After the feed amount becomes 0, the operator pushes the knee lever 20 further to the right to start backstitching. Fig.10 As shown, in the state Tg where the knee lever 20 passes through the direction switching position Pi and reaches the action switching position Pt, the feed dog 10 reversely conveys the sewing object at the feed amount of the initial value RF.

[0095] After the reverse stitching is finished, the operator releases the pedal 18 while maintaining the position of the knee lever 20 at the action switching position Pt to stop the sewing machine motor 12. The sewing of the sewing object is finished by stopping the sewing machine motor 12. After the sewing machine motor 12 stops, the operator presses the knee lever 20 from the action switching position Pt to the maximum position Pm to raise the presser foot 8. Fig.10 As shown, in the state Th where the knee lever 20 passes through the action switching position Pt and reaches the maximum position Pm, the presser foot 8 rises to the maximum value Lm. As the presser foot 8 rises, the presser foot 8 releases the pressure on the sewing object.

[0096] As described above, the operator can press the knee lever 20 from the initial position Po to the right to continuously change from the state Te of implementing straight sewing, through the state of fine-tuning the stitch spacing in the straight sewing, the state Tf of the feed amount becoming 0, and the state Tg of implementing reverse sewing, to the state Th of the presser foot 8 rising.

[0097] As described above, in this embodiment, a series of operations of straight sewing, reverse sewing, and pushing up are continuously performed by operating the knee lever 20. Therefore, the operator can perform the adjustment of the feed amount and pushing up with good operability.

[0098] Fig.11 This is a diagram for explaining the rotation load of the knee lever 20 of this embodiment. Within the rotation range of the knee lever 20, the rotation load of the knee lever 20 between the initial position Po and the action switching position Pt is different from the rotation load of the knee lever 20 between the action switching position Pt and the maximum position Pm. Fig.11 In the example shown, the rotation load of the knee lever 20 between the initial position Po and the action switching position Pt is lighter than the rotation load of the knee lever 20 between the action switching position Pt and the maximum position Pm. By changing the rotation load of the knee lever 20 with the action switching position Pt as the boundary, the operator can recognize the change from the state of adjusting the feed amount to the state of raising the presser foot 8. By changing the rotation load of the knee lever 20 with the action switching position Pt as the boundary, the operating feel of the knee lever 20 is improved.

[0099] When the knee lever 20 rotates from the initial position Po to the action 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 action switching position Pt to the maximum position Pm, in addition to the biasing force of the torsion spring 20E, the biasing force of the second biasing member acts on the knee lever 20, thereby making the rotation load of the knee lever 20 between the action switching position Pt and the maximum position Pm heavier than the rotation load of the knee lever 20 between the initial position Po and the action switching position Pt. As the second biasing member, a second torsion spring, a coil spring, and a leaf spring can be exemplified.

[0100] Furthermore, the rotation load of the knee lever 20 between the initial position Po and the action switching position Pt may be lighter than the rotation load of the knee lever 20 between the action switching position Pt and the maximum position Pm.

[0101] [Fifth Embodiment] In the following description, the same reference numerals are used to denote the same or equivalent components as those in the above-described embodiment, and the description of the components will be simplified or omitted.

[0102] In this embodiment, when the sewing machine motor 12 is driven, the controller 22 switches the conveying direction of the feed tooth 10 from forward conveying to reverse conveying based on the amount of the knee lever 20 pressed from the initial position Po. When the sewing machine motor 12 is stopped, the controller 22 outputs a rising instruction to raise the presser foot 8 based on the amount of the knee lever 20 pressed from the initial position Po.

[0103] The controller 22 outputs a drive command to the sewing machine motor 12, and the sewing machine motor 12 is driven. The controller 22 does not output a drive command, and the sewing machine motor 12 is stopped. The sewing machine motor 12 is driven, which means that the sewing machine 1 is sewing an object to be sewn. The sewing machine motor 12 is stopped, which means that the sewing machine 1 is stopped.

[0104] When outputting a driving command for driving the sewing machine motor 12, the controller 22 switches the conveying direction of the feed tooth 10 from forward conveying to reverse conveying based on the detection signal from the lever sensor 21. That is, in driving the sewing machine motor 12, the controller 22 switches the conveying direction of the feed tooth 10 from forward conveying to reverse conveying based on the amount of pressing of the knee lever 20 as described in the first embodiment, the second embodiment, and the third embodiment.

[0105] The presser foot 8 does not rise while the sewing machine motor 12 is being driven. The presser foot motor 14 does not drive while the sewing machine motor 12 is being driven. The amount of rise of the presser foot 8 is 0 while the sewing machine motor 12 is being driven, and the presser foot 8 continues to press the sewing object.

[0106] Fig.12 The figure used to explain the method of raising the presser foot 8 of this embodiment. Fig.12 In the graph shown, the horizontal axis represents the amount of the knee lever 20 pressed in from the initial position Po. The vertical axis represents the amount of the presser foot 8 raised. As in the above embodiment, the knee lever 20 can rotate within the range of rotation between the initial position Po and the maximum position Pm. The operator can operate the knee lever 20 to raise the presser foot 8.

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

[0108] When the sewing machine motor 12 is stopped, when the knee lever 20 is arranged at the initial position Po, the amount of rise of the presser foot 8 is 0. When the sewing machine motor 12 is stopped, between the initial position Po and the maximum position Pm, the greater the amount of pressing, the more the controller 22 increases the amount of rise of the presser foot 8. The controller 22 sets the rate of change of the amount of rise of the presser foot 8 to a constant. That is, the amount of pressing of the knee lever 20 from the initial position Po is proportional to the amount of rise of the presser foot 8. When the knee lever 20 is arranged at the maximum position Pm, the amount of rise of the presser foot 8 is set to the maximum value Lm.

[0109] In addition, when the sewing machine motor 12 is stopped, the feeding motor 13 operates so that the feeding amount of the feed dog 10 becomes the initial value NF. Thus, when the sewing machine motor 12 is switched from the stopped state to the driven state, the feed dog 10 can forwardly feed the sewing object at the initial value NF.

[0110] In addition, when the state of being driven by the sewing machine motor 12 is switched to a stopped state with the knee lever 20 pressed in, the conveying motor 13 operates in such a manner that the feed amount of the feed tooth 10 changes from the feed amount corresponding to the pressed-in amount of the knee lever 20 to the initial value NF, and the presser foot motor 14 operates in such a manner that the presser foot 8 rises by an amount corresponding to the pressed-in amount of the knee lever 20.

[0111] The state in which the knee lever 20 is pressed in while the sewing machine motor 12 is driven is a state in which fine adjustment is performed in such a way that the feed amount of the feed tooth 10 is reduced and the stitch pitch is reduced. In the state in which the stitch pitch is finely adjusted, when the sewing machine motor 12 is switched to a stopped state, the operator can immediately raise the presser foot 8 by pressing in the knee lever 20.

[0112] In addition, when the knee lever 20 is pressed in and the sewing machine motor 12 is switched from a stopped state to a driven state, the feed motor 13 operates so that the feed amount of the feed tooth 10 becomes the initial value NF, and the presser foot motor 14 operates so that the rise amount of the presser foot 8 becomes 0.

[0113] As described above, in the present embodiment, when the sewing machine motor 12 is driven and then stopped, the operator can immediately raise the presser foot 8 by pressing the knee lever 20. In addition, in the present embodiment, the rotatable range of the knee lever 20 when raising the presser foot 8 is increased, so the operator can finely adjust the raising amount of the presser foot 8.

Claims

1. A sewing machine comprising: Feeding teeth, conveying sewing objects; A knee lever, which is operated by the operator's knee in such a way that it is pressed in from an initial position in a prescribed direction; a rod sensor for detecting an amount of depression of the knee rod from the initial position; and The controller outputs a control command for changing the feed amount of the feed dog based on the detection signal of the rod sensor.

2. The sewing machine according to claim 1, wherein The controller reduces the feeding amount as the pressing amount increases.

3. The sewing machine according to claim 2, wherein The controller increases the rate of change of the feed amount as the push-in amount increases.

4. The sewing machine according to claim 2, wherein The controller sets the change rate of the feed amount to be constant.

5. The sewing machine according to claim 1, wherein The feed tooth can implement forward conveying of the sewing object in a forward direction and reverse conveying of the sewing object in a reverse direction. The controller switches from the forward conveyance to the reverse conveyance based on the pushing amount.

6. The sewing machine according to claim 5, wherein The knee lever can rotate within a rotation range between the initial position and the maximum position, In the rotation range, a direction switching position is specified between the initial position and the maximum position, The controller switches from the forward conveyance to the reverse conveyance when the knee lever moves from the initial position to the direction switching position.

7. The sewing machine according to claim 6, wherein Between the initial position and the direction switching position, the greater the pressing amount, the more the controller reduces the feed amount of the forward conveying, and between the direction switching position and the maximum position, the greater the pressing amount, the more the controller increases the feed amount of the reverse conveying.

8. The sewing machine according to claim 7, wherein 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.

9. The sewing machine according to claim 8, wherein The change rate of the feed amount of the reverse conveying is greater than the change rate of the feed amount of the forward conveying.

10. The sewing machine according to claim 9, wherein In each of the forward conveyance and the reverse conveyance, the controller increases the change rate of the feed amount as the push amount increases.

11. The sewing machine according to claim 9, wherein In each of the forward conveyance and the reverse conveyance, the controller sets a change rate of the feed amount to be constant.

12. The sewing machine according to claim 6, comprising: Input device, The controller changes the direction switching position based on an input signal from the input device.

13. The sewing machine according to claim 3, comprising: The presser foot pushes the sewing object. The knee lever can rotate within a rotation range between the initial position and the maximum position, specifying an action switching position between the initial position and the maximum position, The controller When the knee lever moves from the initial position to the operation switching position, a raising command for raising the presser foot is output.

14. The sewing machine according to claim 13, wherein In the rotation range, a rotation load of the knee lever between the initial position and the action switching position is different from a rotation load of the knee lever between the action switching position and the maximum position.

15. The sewing machine according to claim 5, comprising: The needle bar, which holds the sewing machine needle; A sewing machine motor causes the needle bar and the feed gear to work respectively; and The presser foot pushes the sewing object. The knee lever can rotate within a rotation range between the initial position and the maximum position, The controller During the driving of the sewing machine motor, the forward conveying is switched to the reverse conveying based on the pushing amount. While the sewing machine motor is stopped, a raising command for raising the presser foot is output based on the pressing amount.

Images