Sewing machine

Abstract

The invention provides a sewing machine which suppresses reduction of feeding force of a feeding foot. The sewing machine includes: a needle bar that holds a sewing machine needle and is driven in a vertical direction; and an upper feeding mechanism which is linked with the action of the needle rod, contacts with the cloth from above and conveys the cloth in the feeding direction. The upper feeding mechanism comprises an upper feeding rod which swings, and a feeding foot which is arranged at the lower end part of the upper feeding rod. The feeding foot is provided with a main body which is arranged at the lower end part of the upper feeding rod; a center member protruding downward from the main body, capable of moving up and down with respect to the main body, and in contact with a stitch formed on the cloth by a sewing machine needle; and a pair of side members which protrude downward from the main body, are movable in the vertical direction with respect to the main body, have feeding teeth which come into contact with the cloth, and are disposed on both sides of the center member. When the center member moves upward, the side members move downward. When the center member moves downward, the side members move upward.

Description

Technical Field

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

[0002] In the technical field of sewing machines, a sewing machine equipped with an upper feeding mechanism as disclosed in Patent Document 1 is known.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: German Utility Model Specification No. 8433111 Summary of the Invention

[0006] (I) Technical Problem to be Solved

[0007] The upper feeding mechanism includes a feeding foot that contacts the fabric from above. The feeding foot has: a central member that contacts the stitch, and a pair of side members that contact the fabric. When the amount of protrusion of the stitch from the fabric is large, when the central member contacts the stitch, the side members may not contact the fabric sufficiently. If the side members do not contact the fabric sufficiently, the feeding force of the feeding foot on the fabric may decrease.

[0008] The object of the technology disclosed in this specification is to suppress a decrease in the feeding force of the feeding foot.

[0009] (II) Technical Solution

[0010] This specification discloses a sewing machine. The sewing machine includes: a needle bar that holds a sewing needle and is driven in the vertical direction; an upper feeding mechanism that is linked to the movement of the needle bar, contacts the fabric from above, and conveys the fabric in the feeding direction. The upper feeding mechanism includes: an upper feeding bar that swings; a feeding foot provided at the lower end of the upper feeding bar. The feeding foot has: a main body that is mounted at the lower end of the upper feeding bar; a central member that protrudes downward from the main body and can move in the vertical direction relative to the main body, and contacts the stitch formed in the fabric by the sewing needle; a pair of side members that protrude downward from the main body and can move in the vertical direction relative to the main body, have feeding teeth that contact the fabric, and are arranged on both sides of the central member. When the central member moves upward, the side members move downward. When the central member moves downward, the side members move upward.

[0011] (III) Advantageous Effects

[0012] According to the technology disclosed in this specification, it is possible to suppress a decrease in the feeding force of the feeding foot. Brief Description of the Drawings

[0013] Figure 1 It is a side view showing the sewing machine of the embodiment.

[0014] Figure 2 is a side view schematically showing the internal structure of a sewing machine according to an embodiment.

[0015] Figure 3 is a schematic diagram for explaining the upper feed mechanism and the lower feed mechanism according to an embodiment.

[0016] Figure 4 is a perspective view showing the feed foot of the upper feed mechanism according to an embodiment and the periphery of the feed foot.

[0017] Figure 5 is a perspective view showing the feed foot according to an embodiment.

[0018] Figure 6 is an exploded perspective view showing the feed foot according to an embodiment.

[0019] Figure 7 is a diagram for explaining the operation of the feed foot according to an embodiment.

[0020] Figure 8 is a diagram for explaining the operation of the feed foot according to an embodiment.

[0021] Explanation of reference numerals

[0022] 1: Sewing machine; 2: Sewing machine body; 2A: First arm; 2B: Base; 2C: Second arm; 2D: Head; 3: Needle bar; 3A: Sewing machine needle; 4: Thread take-up lever; 5: Upper feed mechanism; 6: Lower feed mechanism; 7: Needle hole; 8: Needle plate; 8A: Opening; 9: Bend needle; 10: Upper thread regulator; 11: Lower thread regulator; 12: Actuator; 13: Power transmission device; 13A: Arm shaft; 13B: Base shaft; 13C: Bend needle shaft; 13C1: Swing arm; 13D: Pulley; 13E: Pulley; 13F: Timing belt; 13G: Head transmission mechanism; 13H: Power transmission mechanism; 13J: Upper feed transmission mechanism; 13J1: Eccentric cam; 13J2: Swing rod; 13K: Lower feed transmission mechanism; 13K1: Lower shaft; 13K2: Lower shaft; 13K3: Swing arm; 13K4: Swing arm; 13K5: Transmission part; 13K6: Transmission part; 14: Upper thread guide bar; 15: Upper thread guide; 16: Lower thread guide; 17: Presser foot for fabric; 17A: Presser foot part; 18: Biasing mechanism; 18A: Compression coil spring; 31: Upper feed bar; 32: Feed foot; 33: Support shaft; 41: Main body; 41A: Fixed part; 41B: Support part; 41C: Insertion hole; 41D: Central guide part; 41E: Notch part; 41F: Side guide part; 41G: Block part; 41Gt: Lower end face (stopping part); 41H: Threaded hole; 42: Central component; 42A: Presser foot part; 42At: Upper end face; 42B: Mounting part; 42C: Pin part; 43: Side component; 43A: Presser foot part; 43B: Mounting part; 43C: Pin part; 43D: Feed teeth; 44: Cover; 44A: Central recess; 44B: Receiving recess; 44C: Opening; 45: Screw; 46: Rotating body; 46A: First recess; 46B: Second recess; 61: Lower feed component; 62: Feed table; AX: Axis of rotation; D: Spacing; LT: Lower thread; MS: Fabric; P: Needle drop position; SL: Stitch; UT: Upper thread. Detailed implementation mode

[0023] The embodiments will be described below with reference to the accompanying drawings of the specification. In the embodiments, an XYZ orthogonal coordinate system is set, and the positional relationships of the respective parts are described with reference to this XYZ orthogonal coordinate system. The direction parallel to the X-axis within a specified plane is taken as the X-axis direction. The direction parallel to the Y-axis within the specified plane is taken as the Y-axis direction, where the Y-axis is orthogonal to the X-axis. The direction parallel to the Z-axis is taken as the Z-axis direction, where the Z-axis is orthogonal to the specified plane. In addition, the rotational direction or tilting direction centered on the X-axis is taken as the θX direction. The rotational direction or tilting direction centered on the Y-axis is taken as the θY direction. The rotational direction or tilting direction centered on the Z-axis is taken as the θZ direction. In addition, the plane containing the X-axis and the Y-axis is suitably referred to as the XY plane. The plane containing the X-axis and the Z-axis is suitably referred to as the XZ plane. The plane containing the Y-axis and the Z-axis is suitably referred to as the YZ plane. The XY plane is parallel to the specified plane. The XY plane, the XZ plane, and the YZ plane are orthogonal. In addition, in the embodiments, it is assumed that the XY plane is parallel to the horizontal plane. The Z-axis direction is the up-and-down direction. The +Z direction is the upward direction, and the -Z direction is the downward direction. In addition, the XY plane may be inclined with respect to the horizontal plane.

[0024] [Sewing Machine]

[0025] Figure 1 is a side view showing the sewing machine 1 of the embodiment. Figure 2 is a side view schematically showing the internal structure of the sewing machine 1 of the embodiment. In the embodiment, the sewing machine 1 is a double-loop sewing machine that performs double-loop sewing.

[0026] As Figure 1 and Figure 2 shown, the sewing machine 1 includes: a sewing machine body 2; a needle bar 3 that holds the sewing needle 3A and is driven in the up-and-down direction; an upper feeding mechanism 5 that is linked to the movement of the needle bar 3, contacts the fabric MS (refer to Figure 5 from above and conveys the fabric MS in the feeding direction; a lower feeding mechanism 6 that contacts the fabric MS from below and, together with the upper feeding mechanism 5, clamps the fabric MS and conveys it in the feeding direction. In the embodiment, the feeding direction of the fabric MS is the +Y direction.

[0027] In addition, the sewing machine 1 includes: a thread take-up lever 4 that supplies the upper thread to the sewing needle 3A; a needle plate 8 that has a needle hole 7 through which the sewing needle 3A can pass and supports the fabric MS; a looper 9 that swings about a rotation axis AX parallel to the Y-axis, picks up the upper thread from the sewing needle 3A that has passed through the fabric MS and the needle hole 7, and winds it with the lower thread (looper thread); a fabric presser foot 17 (refer to Figure 3 ) that presses the fabric MS against the needle plate 8 from above.

[0028] In addition, the sewing machine 1 includes: an upper thread regulator 10 that supplies the upper thread from a thread supply source; a lower thread regulator 11 that supplies the lower thread from a thread supply source; an actuator 12 that generates power; and a power transmission device 13 that transmits the power generated by the actuator 12 to the needle bar 3 and the looper 9 respectively.

[0029] The sewing machine body 2 is a structure provided with various components including a needle bar 3, an upper feed mechanism 5, and a lower feed mechanism 6. The sewing machine body 2 has: a first arm 2A on which the actuator 12 is provided; a base 2B opposed to the first arm 2A; a second arm 2C that connects one end portion on the +X side of the first arm 2A and the base 2B; and a head 2D that is provided at the other end portion on the -X side of the first arm 2A and supports the needle bar 3.

[0030] The first arm 2A extends in the X-axis direction. The base 2B is arranged to be closer to the -Z direction than the first arm 2A and extends in the X-axis direction. The second arm 2C extends in the Z-axis direction and connects one end portion on the +X side of the first arm 2A and one end portion on the +X side of the base 2B. The head 2D projects from the other end portion on the -X side of the first arm 2A toward the -Z direction.

[0031] The needle bar 3 holds the sewing needle 3A. The needle bar 3 holds one or more sewing needles 3A. In the embodiment, the sewing machine 1 can mount two sewing needles 3A on the needle bar 3 and form stitches in parallel using each sewing needle 3A.

[0032] The needle bar 3 holds the sewing needle 3A in such a manner that the sewing needle 3A is parallel to the Z axis. The needle bar 3 reciprocates in the Z-axis direction. The needle bar 3 is supported by the head 2D. The sewing needle 3A has a thread-passing hole through which the upper thread UT passes. The sewing needle 3A holds the upper thread UT on the inner surface of the thread-passing hole. The upper thread UT for each sewing needle 3A is supplied separately. By the reciprocating movement of the needle bar 3 in the Z-axis direction, the sewing needle 3A reciprocates in the Z-axis direction while holding the upper thread UT.

[0033] The thread take-up lever 4 supplies the upper thread UT to the sewing needle 3A. The thread take-up lever 4 is inserted with the number of upper threads UT corresponding to each sewing needle 3A (two threads) and operates in conjunction with the needle bar 3. The thread take-up lever 4 reciprocates in the Z-axis direction. In the embodiment, the thread take-up lever 4 is a so-called needle bar thread take-up lever that is fixed to the needle bar 3 and reciprocates integrally with the needle bar 3. The thread take-up lever 4 reciprocates in the Z-axis direction while holding each upper thread UT. By the reciprocating movement of the thread take-up lever 4 in the Z-axis direction, the upper thread UT for sewing the fabric MS is drawn out or the upper thread UT is pulled up.

[0034] The needle plate 8 supports the fabric MS. The needle plate 8 is arranged to be in the -Z direction relative to the needle bar 3. The sewing machine needle 3A held by the needle bar 3 faces the needle plate 8. The needle plate 8 has a needle hole 7 through which the sewing machine needle 3A can pass. The sewing machine needle 3A that has penetrated the fabric MS supported by the needle plate 8 passes through the needle hole 7.

[0035] The curved needle 9 picks up the upper thread UT from the sewing machine needle 3A that has penetrated the fabric MS supported by the needle plate 8 and passed through the needle hole 7 of the needle plate 8. The curved needle 9 is arranged to be in the -Z direction relative to the needle plate 8. The curved needle 9 is arranged inside the base 2B. The curved needle 9 is rotatably supported in the θY direction inside the base 2B by the base 2B. The curved needle 9 holds the lower thread LT that is wound with the upper thread UT to form a stitch. The curved needle 9 is provided in the same number as the sewing machine needles 3A. For convenience, only one curved needle 9 is shown in Figure 2 However, in the embodiment, two curved needles 9 are provided corresponding to two sewing machine needles 3A.

[0036] As Figure 1 shown, the upper thread regulator 10 imparts tension to the upper thread UT supplied to the sewing machine needle 3A. The upper thread regulator 10 is supported by the first arm 2A. The upper thread regulator 10 is provided for each upper thread UT. The upper thread regulator 10 is arranged between the upper thread guide bar 14 and the thread take-up lever 4. An upper thread guide 15 is arranged between the thread take-up lever 4 and the sewing machine needle 3A. The upper thread guide 15 is provided on the head 2D. The upper thread guide 15 has a plurality of holes through which the respective upper threads UT are inserted. The upper thread guide 15 guides the respective upper threads UT to the corresponding sewing machine needles 3A.

[0037] The lower thread regulator 11 imparts tension to the lower thread LT supplied to the curved needle 9. The lower thread regulator 11 is supported by the first arm 2A. The lower thread regulator 11 is provided for each lower thread LT. A plurality of lower thread guides 16 are provided on the second arm 2C. Each lower thread guide 16 guides each lower thread LT along the path from the lower thread regulator 11 to the curved needle 9. Each lower thread LT is guided from the lower thread regulator 11 along the second arm 2C in the -Z direction through the lower thread guide 16 and introduced into the base 2B. Each lower thread LT is supplied to the corresponding curved needle 9 via a lower thread guide (not shown) inside the base 2B.

[0038] As Figure 2 shown, the actuator 12 generates the power for reciprocally moving the needle bar 3 in the Z-axis direction. In addition, the actuator 12 generates the power for swinging the curved needle 9 in the θY direction. The actuator 12 includes a pulse motor. The actuator 12 is supported by the first arm 2A.

[0039] The power transmission device 13 transmits the power generated by the actuator 12 to the needle bar 3 and the bent needle 9 respectively. The power generated by the actuator 12 is transmitted to the needle bar 3 via the power transmission device 13. Thus, the needle bar 3, the thread take-up lever 4 fixed to the needle bar 3, and the sewing machine needle 3A held by the needle bar 3 reciprocate in the Z-axis direction. In addition, the power generated by the actuator 12 is transmitted to the bent needle 9 via the power transmission device 13. Thus, the bent needle 9 swings in the θY direction synchronously with the reciprocating movement of the needle bar 3 in the Z-axis direction. The sewing machine 1 sews the fabric MS through the cooperation of the sewing machine needle 3A held by the needle bar 3 and the bent needle 9.

[0040] Figure 2 The schematic structure of the power transmission device 13 is shown. As Figure 2 shown, the power transmission device 13 has: an arm shaft 13A disposed inside the first arm 2A, a base shaft 13B disposed inside the base 2B, and a bent needle shaft 13C disposed inside the base 2B.

[0041] In addition, the power transmission device 13 has: a pulley 13D provided on the arm shaft 13A, a pulley 13E provided on the base shaft 13B, and a timing belt 13F stretched between the pulley 13D and the pulley 13E.

[0042] The arm shaft 13A extends in the X-axis direction. The actuator 12 is connected to one end portion on the +X side of the arm shaft 13A. By the actuation of the actuator 12, the arm shaft 13A rotates in the θX direction.

[0043] The other end portion on the -X side of the arm shaft 13A is connected to the needle bar 3 via the head transmission mechanism 13G. The power generated by the actuator 12 is transmitted to the needle bar 3 via the arm shaft 13A and the head transmission mechanism 13G. Thus, the needle bar 3, the thread take-up lever 4, and the sewing machine needle 3A reciprocate in the Z-axis direction.

[0044] The base shaft 13B extends in the X-axis direction. The base shaft 13B is disposed parallel to the arm shaft 13A. The base shaft 13B can rotate in the θX direction. The power of the actuator 12 is transmitted to the base shaft 13B via the pulley 13D provided on the arm shaft 13A, the pulley 13E provided on the base shaft 13B, and the timing belt 13F stretched between the pulley 13D and the pulley 13E.

[0045] The other end of the -X side of the base shaft 13B is connected to the bent needle shaft 13C via a power transmission mechanism 13H. The power generated by the actuator 12 is transmitted to the bent needle shaft 13C via the arm shaft 13A, the base shaft 13B, and the power transmission mechanism 13H. The power transmission mechanism 13H is an eccentric cam mechanism. The power transmission mechanism 13H connects the swing arm 13C1 and the base shaft 13B, where the swing arm 13C1 is connected to the bent needle shaft 13C. The power transmission mechanism 13H reciprocates the front end portion of the swing arm 13C1 up and down by the power generated by the actuator 12.

[0046] The bent needle shaft 13C is arranged closer to the +Z direction than the base shaft 13B. The bent needle shaft 13C extends in the Y-axis direction. The bent needle shaft 13C can rotate in the θY direction. The bent needle shaft 13C is supported by the base 2B. The swing arm 13C1 extends in the radial direction from the bent needle shaft 13C. The bent needle shaft 13C reciprocates within a specified angular range as the front end portion of the swing arm 13C1 reciprocates in the up and down directions.

[0047] The bent needle 9 is fixed to the bent needle shaft 13C. Thus, the bent needle 9 reciprocates within a specified angular range integrally with the bent needle shaft 13C about the rotation axis AX (in the θY direction). The rotation axis AX is the central axis of the bent needle shaft 13C. The bent needle 9 reciprocates in such a manner that the locus of the up and down reciprocating motion of the front end portion with respect to the sewing machine needle 3A intersects in the X direction. The bent needle 9 has a hook-shaped front end portion. The bent needle 9 has a thread passing hole through which the lower thread LT passes at the front end portion. The bent needle 9 holds the lower thread LT on the inner surface of the thread passing hole. Each bent needle 9 is supplied with its own lower thread LT.

[0048] [Upper feeding mechanism and lower feeding mechanism]

[0049] Figure 3 It is a schematic diagram for explaining the upper feeding mechanism 5 and the lower feeding mechanism 6 of the embodiment. Figure 3 It is a view of the upper feeding mechanism 5 and the lower feeding mechanism 6 observed from the -X side. In addition, in Figure 2 the mechanism for operating the needle bar 3 and the bent needle 9 is shown, and the mechanism for operating the upper feeding mechanism 5 and the lower feeding mechanism 6 is omitted. Figure 3 It represents the mechanism for operating the upper feeding mechanism 5 and the lower feeding mechanism 6, and the mechanism for operating the needle bar 3 and the bent needle 9 is omitted.

[0050] The upper feeding mechanism 5 is provided on the head 2D. The upper feeding mechanism 5 includes: an upper feeding rod 31 that swings, and a feeding foot 32 provided at the lower end of the upper feeding rod 31. The upper feeding rod 31 holds the feeding foot 32. The upper feeding rod 31 is swingably supported on the head 2D. The upper feeding rod 31 extends in the Z-axis direction. The upper end of the upper feeding rod 31 is rotatably mounted on a support shaft 33. The support shaft 33 is connected to the upper feeding transmission mechanism 13J to swing the upper feeding rod 31. The feeding foot 32 is a contact portion that contacts the fabric MS from above and conveys it in the feeding direction. The feeding foot 32 is arranged in the +Z direction of the needle plate 8. The feeding foot 32 is opposed to the lower feeding mechanism 6 in the Z-axis direction via an opening 8A formed in the needle plate 8. The feeding foot 32 moves along a prescribed upper feeding locus in the YZ plane as the upper feeding rod 31 swings.

[0051] The lower feeding mechanism 6 is provided on the base 2B. The lower feeding mechanism 6 is arranged in the -Z direction of the needle plate 8. The lower feeding mechanism 6 has: a lower feeding member 61, and a feeding table 62 that supports the lower feeding member 61. The lower feeding member 61 is a contact portion that contacts the fabric MS from below. The lower feeding member 61 clamps the fabric MS together with the upper feeding mechanism 5. The lower feeding member 61 moves along a prescribed lower feeding locus as the feeding table 62 swings. The lower feeding member 61 protrudes in and out from the opening 8A of the needle plate 8 during the movement along the lower feeding locus. The feeding table 62 holds the lower feeding member 61. The feeding table 62 is swingably supported on the base 2B. The feeding table 62 extends in the Y-axis direction. One end and the other end of the feeding table 62 in the Y-axis direction are respectively connected to a lower shaft 13K1 and a lower shaft 13K2. The feeding table 62 and the lower shaft 13K1 are connected by a swing arm 13K3, and the feeding table 62 and the lower shaft 13K2 are connected by a swing arm 13K4.

[0052] The power transmission device 13 transmits the power generated by the actuator 12 to the upper feeding mechanism 5 and the lower feeding mechanism 6 respectively. The power generated by the actuator 12 is transmitted to the upper feeding mechanism 5 and the lower feeding mechanism 6 via the power transmission device 13. Thus, the upper feeding mechanism 5 and the lower feeding mechanism 6 swing along prescribed feeding loci respectively. The sewing machine 1 conveys the fabric MS in the feeding direction through the cooperation of the upper feeding mechanism 5 and the lower feeding mechanism 6.

[0053] The power transmission device 13 includes: an upper feed transmission mechanism 13J that transmits power to the upper feed mechanism 5; and a lower feed transmission mechanism 13K that transmits power to the lower feed mechanism 6. On the arm shaft 13A, a swing rod 13J2 is installed via an eccentric cam 13J1. The arm shaft 13A is connected to the upper feed transmission mechanism 13J via the swing rod 13J2. The upper feed transmission mechanism 13J is provided on the head 2D and is connected to the support shaft 33 of the upper feed mechanism 5. The power generated by the actuator 12 is transmitted to the support shaft 33 of the upper feed mechanism 5 via the arm shaft 13A and the upper feed transmission mechanism 13J. Thus, the upper feed mechanism 5 moves in conjunction with the movement of the needle bar 3 (sewing machine needle 3A) to perform a feeding action.

[0054] The upper feed transmission mechanism 13J causes the support shaft 33 to move up and down in the Z-axis direction through a cam mechanism, and causes the upper feed rod 31 to reciprocate in the Y-axis direction like a pendulum with the support shaft 33 as a fulcrum. The feed foot 32 provided at the lower end of the upper feed rod 31 performs a revolving motion along an upper feed trajectory through the synthesis of the up-and-down motion and the pendulum motion in the Y-axis direction. The upper feed trajectory is an elliptical (or rectangular) rotational motion in the θX direction in the YZ plane. The upper feed trajectory is composed of an outward path that conveys the fabric MS in the feed direction (+Y direction) and a return path that leaves the fabric MS and returns to the feed start position. In the outward path, the feed foot 32 moves from the feed start position to the feed end position in the feed direction (+Y direction) in a state of being in contact with the fabric MS (a state of descending in the -Z direction). In the return path, the feed foot 32 returns from the feed end position to the -Y direction to the feed start position in a state of moving away from the fabric MS in the +Z direction. The feed start position is a position at or near the -Y direction end of the upper feed trajectory of the feed foot 32. The feed end position is a position at or near the +Y direction end of the upper feed trajectory of the feed foot 32.

[0055] In addition, the upper feed transmission mechanism 13J is also connected to the presser foot 17. The power generated by the actuator 12 is transmitted to the presser foot 17 via the upper feed transmission mechanism 13J. The upper feed transmission mechanism 13J causes the presser foot 17 to move up and down in conjunction with the upper feed mechanism 5 through a cam mechanism. For the presser foot 17, different from the feeding action of the upper feed mechanism 5, the presser foot 17 reciprocates in the Z-axis direction. The upper feed rod 31 and the presser foot 17 operate in an alternating up-and-down manner through the upper feed transmission mechanism 13J. That is, when the upper feed mechanism 5 conveys the fabric MS in the outward path of the upper feed trajectory, the pressing portion 17A of the presser foot 17 rises to move away from the fabric MS. When the upper feed mechanism 5 moves upward away from the fabric MS in the return path of the upper feed trajectory, the pressing portion 17A of the presser foot 17 descends to press the fabric MS. In this way, the sewing machine 1 of the embodiment has an alternating up-and-down mechanism in which the upper feed mechanism 5 and the presser foot 17 move up and down alternately.

[0056] In addition, the sewing machine 1 is provided with a biasing mechanism 18 that biases the upper feed mechanism 5 in the -Z direction. The biasing mechanism 18 includes a compression coil spring 18A. The biasing mechanism 18 biases the support shaft 33 in the -Z direction by using the compression coil spring 18A. The biasing mechanism 18 biases the support shaft 33 via the upper feed transmission mechanism 13J. The upper feed transmission mechanism 13J resists the acting force of the biasing mechanism 18 in the return path of the upper feed trajectory, and raises the upper feed bar 31 and the feed foot 32 in the +Z direction. The biasing mechanism 18 is compressed when raising the upper feed bar 31 and the feed foot 32 in the +Z direction. The biasing mechanism 18 biases the feed foot 32 against the lower feed member 61 via the upper feed bar 31 in the forward path of the upper feed trajectory. In the forward path of the upper feed trajectory, even when the feed foot 32 and the lower feed member 61 are relatively displaced in the Z-axis direction along their respective feed trajectories, the biasing mechanism 18 maintains the contact state (clamping state) between the feed foot 32 and the lower feed member 61 via the fabric MS by the acting force. In addition, the biasing mechanism 18 biases the presser foot 17 for fabric in the -Z direction by using the compression coil spring 18A. Therefore, when the presser foot 17 for fabric descends, the contact state between the presser foot portion 17A and the fabric MS is maintained.

[0057] The lower feed transmission mechanism 13K includes swing arms 13K3 and 13K4 respectively provided on the lower shaft 13K1 and the lower shaft 13K2. As Figure 2 shown, the lower shaft 13K1 is connected to the arm shaft 13A through a transmission portion 13K5. The transmission portion 13K5 includes: an eccentric cam provided on the arm shaft 13A, an arm provided on the lower shaft 13K1, and a connecting rod connecting the eccentric cam and the arm. The lower shaft 13K1 reciprocally swings within a specified angular range by the power generated by the actuator 12. The lower shaft 13K2 is connected to the base shaft 13B through a transmission portion 13K6. The transmission portion 13K6 includes: an eccentric cam provided on the base shaft 13B, an arm provided on the lower shaft 13K2. The lower shaft 13K2 reciprocally swings within a specified angular range by the power generated by the actuator 12 and via the base shaft 13B.

[0058] As Figure 3As shown, the swing arm 13K3 reciprocally rotates within a specified angular range integrally with the lower shaft 13K1, thereby swinging one end portion of the feed table 62. The swing arm 13K4 reciprocally swings within a specified angular range integrally with the lower shaft 13K2, thereby swinging the other end portion of the feed table 62. The feed table 62 swings the lower feed member 61 in a substantially elliptical lower feed trajectory by swinging one end portion and the other end portion. The lower feed trajectory is an elliptical rotational movement in the θX direction within the YZ plane. The lower feed trajectory is composed of an onward path for conveying the fabric MS in the feed direction (+Y direction) and a return path for returning from the fabric MS to the feed start position. In the onward path, the lower feed member 61 moves from the feed start position to the feed end position in the feed direction (+Y direction) while being in contact with the fabric MS (in a state of rising in the +Z direction). In the onward path, the lower feed member 61 protrudes upward from the opening 8A of the needle plate 8 and rises to a position where it contacts the lower surface of the feed foot 32 of the upper feed mechanism 5. Therefore, the fabric MS on the needle plate 8 is clamped between the feed foot 32 and the lower feed member 61. In the return path, the lower feed member 61 returns from the feed end position to the feed start position in the -Y direction while being separated from the fabric MS in the -Z direction. In the return path, the lower feed member 61 is arranged below the opening 8A of the needle plate 8.

[0059] At the moment when the sewing machine needle 3A rises and disengages from the fabric MS, the upper feed mechanism 5 and the lower feed mechanism 6 perform the feed operation for the onward path. The feed foot 32 and the lower feed member 61 clamp the fabric MS at the feed start position and move in the feed direction (+Y direction) in a clamped state. At the moment when the sewing machine needle 3A descends and penetrates the fabric MS, the upper feed mechanism 5 and the lower feed mechanism 6 perform the operation for the return path. The feed foot 32 and the lower feed member 61 separate from the fabric MS at the feed end position and move to the feed start position in the -Y direction. By repeatedly performing the feed operations of the upper feed mechanism 5 and the lower feed mechanism 6 in conjunction with the vertical movement of the sewing machine needle 3A, stitches are formed one by one.

[0060] [Feed foot]

[0061] Figure 4 is a perspective view showing the feed foot 32 of the upper feed mechanism 5 of the embodiment and the periphery of the feed foot 32. Figure 5 is a perspective view showing the feed foot 32 of the embodiment. Figure 6 is an exploded perspective view showing the feed foot 32 of the embodiment. Figure 7 is a diagram for explaining the operation of the feed foot 32 of the embodiment. Figure 8 is a diagram for explaining the operation of the feed foot 32 of the embodiment.

[0062] The feed foot 32 has: a main body 41 mounted on the lower end of the upper feed bar 31, a central member 42 movably supported by the main body 41, a pair of side members 43 movably supported by the main body 41, a cover 44 covering the main body 41 from the -Y direction, a screw 45 fixing the main body 41 and the cover 44, and a rotating body 46 rotatably supported by the main body 41.

[0063] The main body 41 has: a fixing portion 41A fixed to the lower end of the upper feed bar 31, and a supporting portion 41B supporting the central member 42 and the side members 43 respectively. The fixing portion 41A is arranged closer to the +Z side than the supporting portion 41B. An insertion hole 41C is provided on the upper surface of the fixing portion 41A. The insertion hole 41C extends from the upper surface of the fixing portion 41A in the -Z direction. The lower end of the upper feed bar 31 is fixed to the fixing portion 41A by a screw (not shown) in a state of being inserted into the insertion hole 41C.

[0064] The central member 42 can move relative to the main body 41 in the vertical direction. The central member 42 projects downward from the main body 41. The central member 42 has a presser foot portion 42A, a mounting portion 42B, and a pin portion 42C. The presser foot portion 42A is the lower part of the central member 42. The mounting portion 42B is the upper part of the central member 42. The presser foot portion 42A projects downward from the lower surface of the main body 41. The mounting portion 42B is supported by the main body 41. The pin portion 42C projects in the -Y direction from the surface of the mounting portion 42B facing the -Y direction.

[0065] The presser foot portion 42A extends in the Z-axis direction. A part of the presser foot portion 42A is arranged in a cutout portion 41E provided in the lower part of the main body 41. The presser foot portion 42A extends in the -Z direction from the cutout portion 41E. The presser foot portion 42A is arranged on the +Y side of the sewing machine needle 3A. The presser foot portion 42A is arranged in the feed direction (+Y direction) with respect to the sewing machine needle 3A. The lower end of the presser foot portion 42A contacts the stitch SL formed in the fabric MS by the sewing machine needle 3A. The lower end of the presser foot portion 42A is a flat surface. The presser foot portion 42A presses the stitch SL from above and conveys it in the feed direction during the feed operation. The presser foot portion 42A clamps the stitch SL together with a part of the lower feed member 61 and conveys it in the feed direction during the forward path (feed operation) of the feed foot 32.

[0066] The mounting portion 42B is connected to the upper end of the presser foot portion 42A. A pair of mounting portions 42B are provided in the X-axis direction. The mounting portions 42B are arranged to branch from the +Z side end of the presser foot portion 42A in the +X direction and the -X direction respectively. The -X side mounting portion 42B extends from the +Z side end of the presser foot portion 42A in the -X direction and then bends and extends in the +Z direction. The +X side mounting portion 42B extends from the +Z side end of the presser foot portion 42A in the +X direction and then bends and extends in the +Z direction.

[0067] The main body 41 has a central guide portion 41D that guides the central member 42 in the vertical direction. The central guide portion 41D is a guide groove for disposing the mounting portion 42B. The central guide portion 41D extends in the Z-axis direction. A pair of central guide portions 41D are provided in the X-axis direction. The -X side mounting portion 42B is disposed inside the central guide portion 41D on the -X side, and the +X side mounting portion 42B is disposed inside the central guide portion 41D on the +X side. A block portion 41G of the main body 41 is disposed between the pair of central guide portions 41D.

[0068] The pin portion 42C is cylindrical. The pin portion 42C protrudes in the -Y direction from the surface of the mounting portion 42B facing the -Y direction. The pin portions 42C are provided one by one on the pair of mounting portions 42B.

[0069] The side members 43 can move relative to the main body 41 in the vertical direction. A pair of side members 43 are provided. The pair of side members 43 are disposed on both sides of the central member 42 in the X-axis direction. One side member 43 is disposed on the -X side of the central member 42. The other side member 43 is disposed on the +X side of the central member 42. The side members 43 protrude downward from the main body 41. The side members 43 have pressing foot portions 43A, mounting portions 43B, pin portions 43C, and feed teeth 43D. The pressing foot portion 43A is the lower part of the side member 43. The mounting portion 43B is the upper part of the side member 43. The pressing foot portion 43A protrudes downward from the lower surface of the main body 41. The mounting portion 43B is supported by the main body 41. The pin portion 43C protrudes in the -Y direction from the surface of the mounting portion 43B facing the -Y direction. The feed teeth 43D are provided on the lower surface of the pressing foot portion 43A.

[0070] The pressing foot portion 43A faces the -Z direction and extends in the -Y direction. The pressing foot portions 43A are disposed on both sides of the pressing foot portion 42A in the X-axis direction. The pair of pressing foot portions 43A are disposed closer to the -Y side than the pressing foot portion 42A. The lower end portion of the pressing foot portion 43A contacts the fabric MS. The feed teeth 43D are provided on the lower surface of the pressing foot portion 43A. The feed teeth 43D contact the fabric MS. The pressing foot portion 43A presses the fabric MS from above and conveys it in the feed direction during the feed operation. The pressing foot portion 43A clamps the fabric MS together with a part of the lower feed member 61 and conveys it in the feed direction during the forward path (feed operation) of the feed foot 32.

[0071] The mounting portion 43B is connected to the upper end portion of the pressing foot portion 43A. In the side member 43 on the -X side, the mounting portion 43B extends from the +Z side end portion of the pressing foot portion 43A in the -X direction and then bends and extends in the +Z direction. In the side member 43 on the +X side, the mounting portion 43B extends from the +Z side end portion of the pressing foot portion 43A in the +X direction and then bends and extends in the +Z direction.

[0072] The main body 41 has side guide portions 41F that guide the side members 43 in the vertical direction. The side guide portions 41F are guide grooves for disposing the mounting portions 43B. The side guide portions 41F extend in the Z-axis direction. A pair of side guide portions 41F are provided in the X-axis direction. The -X side mounting portion 43B is disposed inside the -X side side guide portion 41F, and the +X side mounting portion 43B is disposed inside the +X side side guide portion 41F.

[0073] The pin portions 43C are cylindrical. The pin portions 43C project in the -Y direction from the surface of the mounting portion 43B facing the -Y direction. The pin portions 43C are respectively provided one by one on the pair of mounting portions 43B.

[0074] The cover 44 is fixed to the end face of the support portion 41B facing the -Y direction so as to cover the center guide portion 41D and the side guide portion 41F from the -Y direction. On the opposing surface of the cover 44 opposing the support portion 41B, there are provided: a central concave portion 44A into which the block portion 41G is inserted, and a pair of receiving concave portions 44B for receiving the rotating body 46. The outer shape of the cover 44 is rectangular. Openings 44C are respectively provided at the four corners of the cover 44.

[0075] The screw 45 fixes the support portion 41B and the cover 44. After the screw 45 is inserted into the opening 44C of the cover 44, it is inserted into the threaded hole 41H provided in the support portion 41B. The thread teeth of the screw 45 are engaged with the thread grooves of the threaded hole 41H, thereby fixing the support portion 41B and the cover 44. In the embodiment, the support portion 41B and the cover 44 are fixed by four screws 45.

[0076] The rotating body 46 is disposed in the space between the support portion 41B and the cover 44. The rotating body 46 is disposed in the receiving concave portion 44B of the cover 44. The rotation axis of the rotating body 46 extends in the Y-axis direction. The rotation axis of the rotating body 46 passes through the center of the rotating body 46.

[0077] The rotating body 46 connects the mounting portion 42B of the center member 42 and the mounting portion 43B of the side member 43. A pair of rotating bodies 46 are provided. The pair of rotating bodies 46 are disposed in the X-axis direction. The -X side rotating body 46 connects the -X side mounting portion 42B and the -X side mounting portion 43B. The +X side rotating body 46 connects the +X side mounting portion 42B and the +X side mounting portion 43B.

[0078] The mounting portion 42B of the center member 42 is mounted on the first portion of the rotating body 46 on one side of the rotation axis of the rotating body 46 in the X-axis direction. The mounting portion 43B of the side member 43 is mounted on the second portion of the rotating body 46 on the other side of the rotation axis of the rotating body 46 in the X-axis direction.

[0079] The rotating body 46 has a first concave portion 46A and a second concave portion 46B. The first concave portion 46A and the second concave portion 46B are respectively arranged to be recessed from the outer peripheral surface of the rotating body 46 toward the radially inner side of the rotation axis. The first concave portion 46A and the second concave portion 46B are point-symmetrical with respect to the rotation axis of the rotating body 46. The first part of the rotating body 46 is disposed in the first concave portion 46A of the rotating body 46. The second part of the rotating body 46 is disposed in the second concave portion 46B of the rotating body 46.

[0080] By disposing the pin portion 42C provided at the upper portion of the central member 42, i.e., the mounting portion 42B, inside the first concave portion 46A, the mounting portion 42B of the central member 42 is mounted on the rotating body 46. By disposing the pin portion 43C provided at the upper portion of the side member 43, i.e., the mounting portion 43B, inside the second concave portion 46B, the mounting portion 43B of the side member 43 is mounted on the rotating body 46.

[0081] In the rotating body 46 on the -X side, the first concave portion 46A is arranged closer to the +X side than the second concave portion 46B. The pin portion 42C of the mounting portion 42B on the -X side is disposed in the first concave portion 46A of the rotating body 46 on the -X side. The pin portion 43C of the mounting portion 43B on the -X side is disposed in the second concave portion 46B of the rotating body 46 on the -X side.

[0082] In the rotating body 46 on the +X side, the first concave portion 46A is arranged closer to the -X side than the second concave portion 46B. The pin portion 42C of the mounting portion 42B on the +X side is disposed in the first concave portion 46A of the rotating body 46 on the +X side. The pin portion 43C of the mounting portion 43B on the +X side is disposed in the second concave portion 46B of the rotating body 46 on the +X side.

[0083] The side member 43 interlocks with the central member 42. The side member 43 moves in a direction opposite to the moving direction of the central member 42. When the central member 42 moves upward, the side member 43 moves downward. When the central member 42 moves downward, the side member 43 moves upward. When the side member 43 moves downward, the central member 42 moves upward. When the side member 43 moves upward, the central member 42 moves downward.

[0084] When the central member 42 moves upward relative to the main body 41, the rotating body 46 connected to the central member 42 via the pin portion 42C rotates in the positive direction. Since the rotating body 46 rotates in the positive direction, the side member 43 connected to the rotating body 46 via the pin portion 43C moves downward.

[0085] When the central member 42 moves downward relative to the main body 41, the rotating body 46 connected to the central member 42 via the pin portion 42C rotates in the opposite direction. Since the rotating body 46 rotates in the opposite direction, the side member 43 connected to the rotating body 46 via the pin portion 43C moves upward.

[0086] As Figure 5 shown, an interval D in the X-axis direction is provided between the presser foot portions 43A of the pair of side members 43. In the region of the interval D, the central member 42 is disposed. Further, as Figure 4 shown, the feed foot 32 is attached to the upper feed bar 31 such that the sewing machine needle 3A is disposed between the pair of side members 43 in the X-axis direction. The sewing machine needle 3A is disposed in the region of the interval D between the pair of side members 43 and is disposed at a position in the -Y direction of the central member 42. In Figure 5 , the needle drop position P of the sewing machine needle 3A is shown. The sewing machine needle 3A passes up and down through the needle drop position P. The central member 42 is disposed on a straight line extending from the needle drop position P (sewing machine needle 3A) in the +Y direction.

[0087] As Figure 5 shown, when the sewing operation of the sewing machine needle 3A is performed while feeding the fabric MS in the +Y direction, a stitch SL extending in the +Y direction from the needle drop position P is formed on the fabric MS. The central member 42 presses and holds a part of the formed stitch SL together with the lower feed member 61 of the lower feed mechanism 6. Accordingly, the central member 42 has a pressing function such that the upper thread UT of the part of the formed stitch SL is not pulled back as the sewing machine needle 3A moves up and down at the needle drop position P and the fabric MS is fed. That is, by the tension acting on the upper thread UT, a new part of the upper thread UT is pulled out from the thread take-up lever 4 side (thread supply source provided on an upper thread spool not shown) and supplied to the sewing machine needle 3A, thereby forming the stitch SL. At this time, the tension also acts on the part of the upper thread UT that has already formed the stitch SL. If the upper thread UT of the part of the stitch SL is pulled out, it causes wrinkles or the like. Therefore, the central member 42 presses the formed stitch SL to suppress the upper thread UT from being pulled out from the stitch SL side.

[0088] In addition, in Figure 4 , the presser foot portion 17A of the fabric presser foot 17 is disposed in the region of the interval D between the pair of side members 43 (see Figure 5 ). Although not shown, through holes for passing the sewing machine needle 3A and through holes for passing the central member 42 are respectively provided in the presser foot portion 17A of the fabric presser foot 17. Therefore, the sewing machine needle 3A and the feed foot 32 operate without interfering with the fabric presser foot 17.

[0089] Moreover, in the embodiment, the central member 42 and the side members 43 are movably mounted to the main body 41 respectively, so as to suppress the central member 42 from leaving the stitch SL or the side members 43 from leaving the fabric MS during the feeding operation.

[0090] As Figure 7 shown, when there is no stitch SL on the fabric MS, the feeding foot 32 presses the fabric MS from above, so that the lower end portions of the central member 42 and the side members 43 are in contact with the fabric MS respectively.

[0091] As Figure 8 shown, when there is a stitch SL on the fabric MS, if the lower end portion of the central member 42 contacts the stitch SL in a manner of pressing the stitch SL from above, the central member 42 moves upward relative to the main body 41. If the central member 42 moves upward, the rotating body 46 rotates forward, so that the side members 43 move downward, and the lower end portions of the side members 43 contact the fabric MS in a manner of pressing the fabric MS from above.

[0092] Based on the protruding amount of the stitch SL from the fabric MS, the upward movement amount of the central member 42 relative to the main body 41 is determined. When the protruding amount of the stitch SL from the fabric MS is small, the upward movement amount of the central member 42 is small. When the protruding amount of the stitch SL from the fabric MS is large, the upward movement amount of the central member 42 relative to the main body 41 is large.

[0093] The side members 43 are interlocked with the central member 42. The side members 43 move in the direction opposite to the moving direction of the central member 42. The movement amount of the central member 42 relative to the main body 41 corresponds to the movement amount of the side members 43 relative to the main body 41 one by one. The larger the upward movement amount of the central member 42 is, the larger the downward movement amount of the side members 43 is. The smaller the upward movement amount of the central member 42 is, the smaller the downward movement amount of the side members 43 is.

[0094] When the central member 42 presses the stitch SL from above, the side members 43 are interlocked with the central member 42 and press the fabric MS from above. As Figure 8 shown, during the feeding operation, the central member 42 moves upward and the side members 43 move downward, so that the central member 42 is in sufficient contact with the stitch SL and the side members 43 are in sufficient contact with the fabric MS. In a state where the central member 42 is in sufficient contact with the stitch SL and the side members 43 are in sufficient contact with the fabric MS, the feeding foot 32 performs the feeding operation, so that it is possible to suppress the reduction of the feeding force of the feeding foot 32 on the fabric MS.

[0095] As Figure 8As shown, when the central member 42 moves upward by a predetermined height relative to the main body 41, the lower end surface 41Gt of the block portion 41G comes into contact with the upper end surface 42At of the pressing foot portion 42A. By the contact between the lower end surface 41Gt of the block portion 41G and the upper end surface 42At of the pressing foot portion 42A, the movement of the central member 42 relative to the main body 41 to a position higher than the predetermined height is restricted. The lower end surface 41Gt of the block portion 41G functions as a stopper to restrict the movement of the central member 42 relative to the main body 41 to a position higher than the predetermined height.

[0096] As described above, the upward feeding locus is composed of an outward path for conveying the fabric MS in the feeding direction (+Y direction) and a return path for returning from the fabric MS to the feeding start position. In the outward path, the feeding foot 32 moves from the feeding start position to the feeding end position in the feeding direction (+Y direction) while being in contact with the stitch SL (in a state of descending in the -Z direction). In the return path, the feeding foot 32 returns from the feeding end position to the feeding start position in the -Y direction while moving away from the fabric MS in the +Z direction. In the return path, when the feeding foot 32 rises in a manner of moving away from the fabric MS, due to the action of gravity, the side member 43 moves downward. If the side member 43 moves downward, the central member 42 moves upward. By the lower end surface 41Gt of the block portion 41G, the movement of the central member 42 to a position higher than the predetermined height is restricted. Therefore, it is possible to prevent the side member 43 from protruding excessively downward from the main body 41 or falling from the main body 41. In the return path of the upward feeding locus, it is possible to prevent the side member 43 from coming into contact with the fabric MS.

[0097] The feeding foot 32 that has moved to the feeding start position descends in a manner of approaching the fabric MS. When the feeding foot 32 approaches the fabric MS, the central member 42 first comes into contact with the stitch SL and moves upward relative to the main body 41, and the side member 43 moves downward relative to the main body 41 and comes into contact with the fabric MS. The feeding foot 32 can perform a feeding operation while the central member 42 is in sufficient contact with the stitch SL and the side member 43 is in sufficient contact with the fabric MS.

[0098] [Effect]

[0099] As described above, according to the embodiment, the sewing machine 1 includes: a needle bar 3 that holds a sewing needle 3A and is driven in the vertical direction; an upper feed mechanism 5 that is linked to the movement of the needle bar 3, contacts the fabric MS from above, and conveys the fabric MS in the feed direction. The upper feed mechanism 5 includes: an upper feed bar 31 that swings; a feed foot 32 provided at the lower end of the upper feed bar 31. The feed foot 32 has: a main body 41 that is mounted at the lower end of the upper feed bar 31; a central member 42 that projects downward from the main body 41 and is movable relative to the main body 41 in the vertical direction and contacts a stitch SL formed in the fabric MS by the sewing needle 3A; a pair of side members 43 that project downward from the main body 41 and are movable relative to the main body 41 in the vertical direction, have feed teeth 43D that contact the fabric MS, and are arranged on both sides of the central member 42. When the central member 42 moves upward, the side members 43 move downward. When the central member 42 moves downward, the side members 43 move upward.

[0100] According to the embodiment, during the feeding operation, when the feed foot 32 descends to contact the fabric MS at the start position of feeding, the central member 42 that contacts the stitch SL moves upward relative to the main body 41 based on the amount of protrusion of the stitch SL from the fabric MS, and the side members 43 move downward relative to the main body 41 in conjunction with the central member 42 and contact the fabric MS. The feed foot 32 can perform the feeding operation in a state where the central member 42 is in full contact with the stitch SL and the side members 43 are in full contact with the fabric MS. Thereby, it is possible to suppress a decrease in the feeding force of the feed foot 32 on the fabric MS.

[0101] For example, when double-loop sewing a thin and hard fabric MS such as an airbag with thick thread, the amount of protrusion of the stitch SL from the fabric MS may be large. When the amount of protrusion of the stitch SL from the fabric MS is large, when the central member 42 contacts the stitch SL, the side members 43 may not be in full contact with the fabric MS. According to the embodiment, corresponding to the amount of protrusion of the stitch SL from the fabric MS, the central member 42 that contacts the stitch SL moves upward relative to the main body 41, and the side members 43 move downward relative to the main body 41 in conjunction with the central member 42 and contact the fabric MS. Therefore, the central member 42 can be in full contact with the stitch SL, and the side members 43 can also be in full contact with the fabric MS. The feed foot 32 can convey the fabric MS in the feed direction with a high feeding force in a state where the central member 42 is in full contact with the stitch SL and the side members 43 are in full contact with the fabric MS.

[0102] The feed foot 32 has a rotating body 46 rotatably supported by the main body 41. The central member 42 has a pin portion 42C, and the pin portion 42C is disposed in a first recess 46A on one side of the rotating body 46 closer to the rotation axis. The side member 43 has a pin portion 43C, and the pin portion 43C is disposed in a second recess 46B on the other side of the rotating body 46 closer to the rotation axis. The rotating body 46 functions as a lever. When the central member 42 contacts the stitch SL and moves upward, the rotating body 46 rotates, and by the rotation of the rotating body 46, the pair of side members 43 move downward.

[0103] The main body 41 has a central guide portion 41D that guides the central member 42 in the vertical direction and a side guide portion 41F that guides the side member 43 in the vertical direction. Thus, the central member 42 and the side member 43 can move smoothly in the vertical direction, respectively.

[0104] The main body 41 has a lower end surface 41Gt that restricts the central member 42 from moving upward relative to the main body 41 to a position higher than a specified height. Thus, in the return path of the upper feed locus, it is possible to suppress the side member 43 from protruding excessively downward from the main body 41 or falling from the main body 41. In the return path of the upper feed locus, it is possible to suppress the side member 43 from contacting the fabric MS.

Claims

1. A sewing machine comprising: a needle bar which holds the sewing machine needle and is driven in the up and down directions; The upper feeding mechanism is linked to the movement of the needle bar, contacts the cloth from above and conveys the cloth in the feeding direction, The upper feeding mechanism comprises: An upper feed rod for swinging, and a feed foot provided at the lower end of the upper feed rod, The feed foot has: A main body, which is mounted on the lower end of the upper feed rod; a center member protruding downward from the main body, movable in the up-down direction relative to the main body, and contacting a stitch formed on the fabric by the sewing machine needle; a pair of side members, which protrude downward from the main body, are movable in the up-down direction relative to the main body, have feed teeth that contact the cloth, and are arranged on both sides of the central member, When the center member moves upward, the side members move downward, and when the center member moves downward, the side members move upward.

2. The sewing machine according to claim 1, characterized in that: The feed foot has a rotating body rotatably supported on the main body. The central component is mounted on a first portion of the rotating body closer to the rotating shaft. The side member is attached to a second portion of the rotating body on the other side of the rotating shaft.

3. The sewing machine according to claim 2, characterized in that: The first portion is a first recessed portion provided on the rotating body, The second portion is a second recessed portion provided on the rotating body, The pin portion provided on the upper portion of the central member is arranged in the first recess, so that the central member is mounted on the rotating body. The pin portion provided on the upper portion of the side member is arranged in the second recessed portion, so that the side member is attached to the rotating body.

4. The sewing machine according to claim 1, characterized in that: The subject has: a center guide portion that guides the center member in an up-down direction; The side guide portion guides the side member in the up-down direction.

5. The sewing machine according to claim 1, characterized in that: The main body has a stopper, The stopper restricts movement of the core member relative to the body to a position above a predetermined height.

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