Sewing machine

Abstract

To suppress deterioration in a feeding force by a feed foot.SOLUTION: A sewing machine includes: a needle bar driven in the vertical direction by holding a sewing needle; and a top feed mechanism interlocked with the motion of the needle bar, and for feeding fabric in the feed direction by coming into contact with the fabric from above. The top feed mechanism includes: a top fed bar that swings; and a feed foot provided at a lower end part of the top feed bar. The feed foot includes: a body mounted on the lower end part of the top feed bar; a center member protruding downward from the body, movable in the vertical direction with respect to the body, and for coming into contact with seams formed in the fabric by the sewing needle; and a pair of side members protruding downward from the body, movable in the vertical direction with respect to the body, having a feed dog coming into contact with the fabric, and arranged 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.SELECTED DRAWING: Figure 8

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, a sewing machine equipped with a feed mechanism as disclosed in Patent Document 1 is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The feed mechanism includes a feed foot that contacts the fabric from above. The feed foot has a center member that contacts the seam and a pair of side members that contact the fabric. When the protruding amount of the seam from the fabric is large, when the center member contacts the seam, the side members may not sufficiently contact the fabric. When the side members do not sufficiently contact the fabric, the feeding force of the fabric by the feed foot may decrease.

[0005] The technology disclosed in this specification aims to suppress a decrease in the feeding force by the feed foot.

[0006] This specification discloses a sewing machine. The sewing machine includes a needle bar that holds a sewing needle and is driven vertically, and a feed mechanism that operates in conjunction with the movement of the needle bar, contacts the fabric from above, and feeds the fabric in the feeding direction. The feed mechanism includes a rocking feed bar and a feed foot provided at the lower end of the feed bar. The feed foot includes a body attached to the lower end of the feed bar, a center member that protrudes downward from the body, is movable vertically with respect to the body, and contacts the seam formed in the fabric by the sewing needle, and a pair of side members that protrude downward from the body, are movable vertically with respect to the body, have feed teeth that contact the fabric, 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.

Advantages of the Invention

[0007] According to the technology disclosed in this specification, a decrease in the feeding force by the feed foot is suppressed.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described with reference to the drawings. In the embodiments, an XYZ orthogonal coordinate system is set, and the positional relationship of each part will be described with reference to this XYZ orthogonal coordinate system. The direction parallel to the X-axis in a predetermined plane is defined as the X-axis direction. The direction parallel to the Y-axis in the predetermined plane orthogonal to the X-axis is defined as the Y-axis direction. The direction parallel to the Z-axis orthogonal to the predetermined plane is defined as the Z-axis direction. Also, the rotational direction or tilting direction about the X-axis is defined as the θX direction. The rotational direction or tilting direction about the Y-axis is defined as the θY direction. The rotational direction or tilting direction about the Z-axis is defined as the θZ direction. Also, the plane including the X-axis and the Y-axis is appropriately referred to as the XY plane. The plane including the X-axis and the Z-axis is appropriately referred to as the XZ plane. The plane including the Y-axis and the Z-axis is appropriately referred to as the YZ plane. The XY plane is parallel to the predetermined plane. The XY plane, the XZ plane, and the YZ plane are orthogonal to each other. Also, in the embodiments, it is assumed that the XY plane is parallel to the horizontal plane. The Z-axis direction is the vertical direction. The +Z direction is the upward direction and the -Z direction is the downward direction. Note that the XY plane may be inclined with respect to the horizontal plane.

[0010] [Sewing Machine] FIG. 1 is a side view showing a sewing machine 1 according to an embodiment. FIG. 2 is a side view schematically showing the internal structure of the sewing machine 1 according to the embodiment. In the embodiment, the sewing machine 1 is a double-loop sewing machine that performs double-loop sewing.

[0011] As shown in FIGS. 1 and 2, the sewing machine 1 includes a sewing machine body 2, a needle bar 3 that holds a sewing machine needle 3A and is driven in the vertical direction, an upper feed mechanism 5 that is interlocked with the operation of the needle bar 3, contacts the fabric MS (see FIG. 5) from above, and feeds the fabric MS in the feed direction, and a lower feed mechanism 6 that contacts the fabric MS from below and sandwiches and feeds the fabric MS in the feed direction together with the upper feed mechanism 5. In the embodiment, the feed direction of the fabric MS is the +Y direction.

[0012] Further, the sewing machine 1 includes a balance 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, scoops up the upper thread from the sewing needle 3A that has passed through the fabric MS and the needle hole 7, and entwines it with the lower thread (looper thread), and a fabric presser 17 (see FIG. 3) that presses the fabric MS against the needle plate 8 from above.

[0013] The sewing machine 1 further includes an upper thread conditioner 10 to which the upper thread is supplied from a thread supply source, a lower thread conditioner 11 to which the lower thread is supplied 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 each of the needle bar 3 and the looper 9.

[0014] The sewing machine body 2 is a structure in which each member including the needle bar 3, the upper feed mechanism 5, and the lower feed mechanism 6 is provided. The sewing machine body 2 includes a first arm 2A on which the actuator 12 is provided, a bed 2B facing the first arm 2A, a second arm 2C connecting one end portion on the +X side of the first arm 2A and the bed 2B, and a head 2D provided at the other end portion on the -X side of the first arm 2A and supporting the needle bar 3.

[0015] The first arm 2A extends in the X-axis direction. The bed 2B is disposed in the -Z direction relative to 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 bed 2B. The head 2D protrudes in the -Z direction from the other end portion on the -X side of the first arm 2A.

[0016] The needle bar 3 holds the sewing needle 3A. The needle bar 3 holds one or a plurality of sewing needles 3A. In the embodiment, the sewing machine 1 can attach two sewing needles 3A to the needle bar 3 and form stitches in parallel with each sewing needle 3A.

[0017] The needle bar 3 holds the sewing needle 3A such that the sewing needle 3A and the Z-axis are parallel. 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 passage hole through which the upper thread UT passes. The sewing needle 3A holds the upper thread UT on the inner surface of the thread passage hole. Separate upper threads UT are supplied to each sewing needle 3A. As the needle bar 3 reciprocates in the Z-axis direction, the sewing needle 3A reciprocates in the Z-axis direction while holding the upper thread UT.

[0018] The thread carrier 4 supplies the upper thread UT to the sewing needle 3A. The thread carrier 4 has the number (two) of upper threads UT corresponding to each sewing needle 3A inserted therethrough and operates in conjunction with the needle bar 3. The thread carrier 4 reciprocates in the Z-axis direction. In the embodiment, the thread carrier 4 is fixed to the needle bar 3 and reciprocates integrally with the needle bar 3, which is a so-called needle bar thread carrier. The thread carrier 4 reciprocates in the Z-axis direction while holding each upper thread UT. By reciprocating in the Z-axis direction, the thread carrier 4 pays out the upper thread UT used for sewing the fabric MS or pulls up the upper thread UT.

[0019] The needle plate 8 supports the fabric MS. The needle plate 8 is disposed in the -Z direction relative to the needle bar 3. The sewing needle 3A held by the needle bar 3 and the needle plate 8 face each other. The needle plate 8 has a needle hole 7 through which the sewing needle 3A can pass. The sewing needle 3A passing through the fabric MS supported by the needle plate 8 passes through the needle hole 7.

[0020] The looper 9 scoops up the upper thread UT from the sewing needle 3A that has passed through the fabric MS supported by the needle plate 8 and through the needle hole 7 of the needle plate 8. The looper 9 is disposed in the -Z direction relative to the needle plate 8. The looper 9 is disposed inside the bed 2B. The looper 9 is supported by the bed 2B so as to be rotatable in the θY direction inside the bed 2B. The looper 9 holds the lower thread LT that is intertwined with the upper thread UT to form a stitch. The number of loopers 9 provided is the same as the number of sewing needles 3A. For the sake of convenience, only one looper 9 is shown in FIG. 2, but in the embodiment, two loopers 9 are provided corresponding to two sewing needles 3A.

[0021] As shown in FIG. 1, the upper thread regulator 10 applies tension to the upper thread UT supplied to the sewing 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 disposed between the upper thread guide rod 14 and the balance 4. An upper thread guide 15 is disposed between the balance 4 and the sewing needle 3A. The upper thread guide 15 is provided on the head 2D. The upper thread guide 15 has a plurality of holes for individually inserting each upper thread UT. The upper thread guide 15 guides each upper thread UT to the corresponding sewing needle 3A.

[0022] The lower thread regulator 11 applies tension to the lower thread LT supplied to the looper 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 looper 9. Each lower thread LT is guided by the lower thread guide 16 from the lower thread regulator 11 along the second arm 2C in the -Z direction and introduced into the bed 2B. Each lower thread LT is supplied to the corresponding looper 9 through a lower thread guide (not shown) in the bed 2B.

[0023] As shown in FIG. 2, the actuator 12 generates power to reciprocate the needle bar 3 in the Z-axis direction. Further, the actuator 12 generates power to swing the looper 9 in the θY direction. The actuator 12 includes a pulse motor. The actuator 12 is supported by the first arm 2A.

[0024] The power transmission device 13 transmits the power generated by the actuator 12 to each of the needle bar 3 and the looper 9. The power generated by the actuator 12 is transmitted to the needle bar 3 via the power transmission device 13. Thereby, the needle bar 3, the balance 4 fixed to the needle bar 3, and the sewing needle 3A held by the needle bar 3 reciprocate in the Z-axis direction. Also, the power generated by the actuator 12 is transmitted to the looper 9 via the power transmission device 13. Thereby, the looper 9 swings in the θY direction in synchronization with the reciprocating movement of the needle bar 3 in the Z-axis direction. The sewing machine 1 sews the fabric MS by the cooperation of the sewing needle 3A held by the needle bar 3 and the looper 9.

[0025] FIG. 2 shows a schematic configuration of the power transmission device 13. As shown in FIG. 2, the power transmission device 13 includes an arm shaft 13A disposed inside the first arm 2A, a bed shaft 13B disposed inside the bed 2B, and a looper shaft 13C disposed inside the bed 2B.

[0026] Also, the power transmission device 13 includes a pulley 13D provided on the arm shaft 13A, a pulley 13E provided on the bed shaft 13B, and a timing belt 13F wound around the pulley 13D and the pulley 13E.

[0027] 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 operation of the actuator 12, the arm shaft 13A rotates in the θX direction.

[0028] 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. Thereby, the needle bar 3, the balance 4, and the sewing needle 3A reciprocate in the Z-axis direction.

[0029] The bed shaft 13B extends in the X-axis direction. The bed shaft 13B is arranged parallel to the arm shaft 13A. The bed shaft 13B is rotatable in the θX direction. The power of the actuator 12 is transmitted to the bed shaft 13B via a pulley 13D provided on the arm shaft 13A, a pulley 13E provided on the bed shaft 13B, and a timing belt 13F stretched between the pulley 13D and the pulley 13E.

[0030] The other end of the bed shaft 13B on the -X side is connected to the looper shaft 13C via a power transmission mechanism 13H. The power generated by the actuator 12 is transmitted to the looper shaft 13C via the arm shaft 13A, the bed shaft 13B, and the power transmission mechanism 13H. The power transmission mechanism 13H is an eccentric cam mechanism. The power transmission mechanism 13H connects a swing arm 13C1 connected to the looper shaft 13C and the bed shaft 13B. The power transmission mechanism 13H reciprocates the tip of the swing arm 13C1 up and down by the power generated by the actuator 12.

[0031] The looper shaft 13C is arranged in the +Z direction relative to the bed shaft 13B. The looper shaft 13C extends in the Y-axis direction. The looper shaft 13C is rotatable in the θY direction. The looper shaft 13C is supported by the bed 2B. The swing arm 13C1 extends radially from the looper shaft 13C. The looper shaft 13C reciprocally swings within a predetermined angular range as the tip of the swing arm 13C1 reciprocates in the vertical direction.

[0032] The looper 9 is fixed to the looper shaft 13C. As a result, the looper 9 swings back and forth within a predetermined angular range around the rotation axis AX (in the θY direction) integrally with the looper shaft 13C. The rotation axis AX is the central axis of the looper shaft 13C. The looper 9 swings back and forth such that the tip portion intersects the trajectory of the vertical reciprocating motion of the sewing needle 3A in the X direction. The looper 9 has a hook-shaped tip portion. The looper 9 has a thread passage hole through which the lower thread LT passes at the tip portion. The looper 9 holds the lower thread LT on the inner surface of the thread passage hole. Separate lower threads LT are supplied to each looper 9.

[0033] [Upper feed mechanism and lower feed mechanism] FIG. 3 is a schematic diagram for explaining the upper feed mechanism 5 and the lower feed mechanism 6 according to the embodiment. FIG. 3 is a view of the upper feed mechanism 5 and the lower feed mechanism 6 as seen from the -X side. In FIG. 2, the mechanisms for operating the needle bar 3 and the looper 9 are shown, and the mechanisms for operating the upper feed mechanism 5 and the lower feed mechanism 6 are omitted. FIG. 3 shows the mechanisms for operating the upper feed mechanism 5 and the lower feed mechanism 6, and omits the mechanisms for operating the needle bar 3 and the looper 9.

[0034] The upper feed mechanism 5 is provided in the head 2D. The upper feed mechanism 5 includes a swinging upper feed bar 31 and a feed foot 32 provided at the lower end of the upper feed bar 31. The upper feed bar 31 holds the feed foot 32. The upper feed bar 31 is swingably supported by the head 2D. The upper feed bar 31 extends in the Z-axis direction. The upper end of the upper feed bar 31 is rotatably attached to a support shaft 33. The support shaft 33 is connected to the upper feed transmission mechanism 13J to swing the upper feed bar 31. The feed foot 32 is a contact portion that contacts the fabric MS from above and feeds it in the feed direction. The feed foot 32 is disposed in the +Z direction of the needle plate 8. The feed foot 32 faces the lower feed mechanism 6 in the Z-axis direction through an opening 8A formed in the needle plate 8. The feed foot 32 moves along a predetermined upper feed trajectory within the YZ plane as the upper feed bar 31 swings.

[0035] The lower feed mechanism 6 is provided on the bed 2B. The lower feed mechanism 6 is arranged in the -Z direction of the needle plate 8. The lower feed mechanism 6 has a lower feed 61 and a feed base 62 that supports the lower feed 61. The lower feed 61 is a contact portion that contacts the fabric MS from below. The lower feed 61 clamps the fabric MS together with the upper feed mechanism 5. The lower feed 61 moves along a predetermined lower feed track as the feed base 62 swings. The lower feed 61 protrudes up and down from the opening 8A of the needle plate 8 during the movement along the lower feed track. The feed base 62 holds the lower feed 61. The feed base 62 is swingably supported by the bed 2B. The feed base 62 extends in the Y-axis direction. One end and the other end of the feed base 62 in the Y-axis direction are respectively connected to the lower shaft 13K1 and the lower shaft 13K2. The feed base 62 and the lower shaft 13K1 are connected by a swing arm 13K3, and the feed base 62 and the lower shaft 13K2 are connected by a swing arm 13K4.

[0036] The power transmission device 13 transmits the power generated by the actuator 12 to each of the upper feed mechanism 5 and the lower feed mechanism 6. The power generated by the actuator 12 is transmitted to the upper feed mechanism 5 and the lower feed mechanism 6 via the power transmission device 13. Thereby, the upper feed mechanism 5 and the lower feed mechanism 6 swing along predetermined feed tracks respectively. The sewing machine 1 feeds the fabric MS in the feed direction by the cooperation of the upper feed mechanism 5 and the lower feed mechanism 6.

[0037] 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. A swing rod 13J2 is attached to the arm shaft 13A 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. Thereby, the upper feed mechanism 5 performs a feed operation in conjunction with the operation of the needle bar 3 (sewing needle 3A).

[0038] The upward feed transmission mechanism 13J causes the support shaft 33 to reciprocate in the Y-axis direction like a pendulum with the support shaft 33 as a fulcrum while moving the support shaft 33 up and down in the Z-axis direction by a cam mechanism. The feed foot 32 provided at the lower end of the upward feed bar 31 performs a circular motion on the upward feed track by the combination of the vertical motion and the pendulum motion in the Y-axis direction. The upward feed track is an elliptical (or rectangular) rotational motion in the θX direction within the YZ plane. The upward feed track is composed of an outward path that feeds the fabric MS in the feed direction (+Y direction) and a return path that returns from the fabric MS to the feed start position. In the outward path, the feed foot 32 moves in the feed direction (+Y direction) from the feed start position to the feed end position while in contact with the fabric MS (in a state of descending in the -Z direction). In the return path, the feed foot 32 returns in the -Y direction from the feed end position to the feed start position while being separated from the fabric MS in the +Z direction. The feed start position is a position at or near the -Y direction end of the upward feed track of the feed foot 32. The feed end position is a position at or near the +Y direction end of the upward feed track of the feed foot 32.

[0039] Note that the upward feed transmission mechanism 13J is also connected to the fabric presser 17. The power generated by the actuator 12 is transmitted to the fabric presser 17 via the upward feed transmission mechanism 13J. The upward feed transmission mechanism 13J moves the fabric presser 17 up and down in conjunction with the upward feed mechanism 5 by a cam mechanism. Unlike the feeding operation of the upward feed mechanism 5, the fabric presser 17 reciprocates in the Z-axis direction. The upward feed bar 31 and the fabric presser 17 operate to move up and down alternately by the upward feed transmission mechanism 13J. That is, when the upward feed mechanism 5 is feeding the fabric MS in the outward path of the upward feed track, the pressing portion 17A of the fabric presser 17 rises and separates from the fabric MS. When the upward feed mechanism 5 is separated upward from the fabric MS in the return path of the upward feed track, the pressing portion 17A of the fabric presser 17 descends and presses the fabric MS. Thus, the sewing machine 1 of the embodiment has an alternating up-and-down mechanism in which the upward feed mechanism 5 and the fabric presser 17 move up and down alternately.

[0040] Further, the sewing machine 1 includes a biasing mechanism 18 that biases the upward 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 the compression coil spring 18A. The biasing mechanism 18 biases the support shaft 33 via the upward feed transmission mechanism 13J. In the return path of the upward feed track, the upward feed transmission mechanism 13J raises the upward feed bar 31 and the feed foot 32 in the +Z direction against the biasing force of the biasing mechanism 18. The biasing mechanism 18 is compressed when raising the upward feed bar 31 and the feed foot 32 in the +Z direction. In the forward path of the upward feed track, the biasing mechanism 18 biases the feed foot 32 against the downward feed 61 via the upward feed bar 31. In the forward path of the upward feed track, the biasing mechanism 18 maintains the contact state (clamping state) via the fabric MS between the feed foot 32 and the downward feed 61 by the biasing force even when the feed foot 32 and the downward feed 61 are relatively displaced in the Z-axis direction according to their respective feed tracks. Note that the biasing mechanism 18 biases the fabric presser 17 in the -Z direction by the compression coil spring 18A. Therefore, the contact state between the pressing portion 17A and the fabric MS is maintained when the fabric presser 17 descends.

[0041] The downward feed transmission mechanism 13K includes a swing arm 13K3 and a swing arm 13K4 provided on the lower shaft 13K1 and the lower shaft 13K2, respectively. As shown in FIG. 2, the lower shaft 13K1 is connected to the arm shaft 13A by 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 is reciprocally swung within a predetermined angular range by the power generated by the actuator 12. The lower shaft 13K2 is connected to the bed shaft 13B by a transmission portion 13K6. The transmission portion 13K6 includes an eccentric cam provided on the bed shaft 13B and an arm provided on the lower shaft 13K2. The lower shaft 13K2 is reciprocally swung within a predetermined angular range via the bed shaft 13B by the power generated by the actuator 12.

[0042] As shown in Fig. 3, the swing arm 13K3 rotates reciprocally within a predetermined angular range integrally with the lower shaft 13K1 to swing one end of the feed table 62. The swing arm 13K4 rotates reciprocally within a predetermined angular range integrally with the lower shaft 13K2 to swing the other end of the feed table 62. The feed table 62 swings the lower feed 61 in a substantially elliptical lower feed orbit by the swinging of one end and the other end. The lower feed orbit is an elliptical rotational motion in the θX direction within the YZ plane. The lower feed orbit is composed of an outward path that feeds the fabric MS in the feed direction (+Y direction) and a return path that returns from the fabric MS to the feed start position. In the outward path, the lower feed 61 moves in the feed direction (+Y direction) from the feed start position to the feed end position while being in contact with the fabric MS (in a state of rising in the +Z direction). In the outward path, the lower feed 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 61. In the return path, the lower feed 61 returns in the -Y direction from the feed end position to the feed start position while being separated from the fabric MS in the -Z direction. In the return path, the lower feed 61 is disposed below the opening 8A of the needle plate 8.

[0043] At the timing when the sewing needle 3A rises and detaches from the fabric MS, the upper feed mechanism 5 and the lower feed mechanism 6 perform the feeding operation in the outward path. The feed foot 32 and the lower feed 61 clamp the fabric MS at the feed start position and move in the feed direction (+Y direction) while being clamped. At the timing when the sewing needle 3A descends and penetrates the fabric MS, the upper feed mechanism 5 and the lower feed mechanism 6 perform the operation in the return path. The feed foot 32 and the lower feed 61 separate from the fabric MS at the feed end position and move in the -Y direction to the feed start position. In conjunction with the vertical movement of the sewing needle 3A, the feeding operations of the upper feed mechanism 5 and the lower feed mechanism 6 are repeated, thereby forming stitches one by one.

[0044] [Feed foot] FIG. 4 is a perspective view showing the feed foot 32 of the upward feeding mechanism 5 according to the embodiment and the periphery of the feed foot 32. FIG. 5 is a perspective view showing the feed foot 32 according to the embodiment. FIG. 6 is an exploded perspective view showing the feed foot 32 according to the embodiment. FIG. 7 is a diagram for explaining the operation of the feed foot 32 according to the embodiment. FIG. 8 is a diagram for explaining the operation of the feed foot 32 according to the embodiment.

[0045] The feed foot 32 includes a body 41 attached to the lower end of the upward feed bar 31, a center member 42 movably supported by the body 41, a pair of side members 43 movably supported by the body 41, a cover 44 covering the body 41 from the -Y direction, a screw 45 fixing the body 41 and the cover 44, and a rotating body 46 rotatably supported by the body 41.

[0046] The body 41 has a fixing portion 41A fixed to the lower end of the upward feed bar 31 and a support portion 41B supporting each of the center member 42 and the side members 43. The fixing portion 41A is disposed on the +Z side of the support portion 41B. An insertion hole 41C is provided on the upper surface of the fixing portion 41A. The insertion hole 41C extends in the -Z direction from the upper surface of the fixing portion 41A. The lower end of the upward 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.

[0047] The center member 42 is movable in the vertical direction with respect to the body 41. The center member 42 protrudes downward from the body 41. The center member 42 has a pressing portion 42A, a mounting portion 42B, and a pin portion 42C. The pressing portion 42A is the lower part of the center member 42. The mounting portion 42B is the upper part of the center member 42. The pressing portion 42A protrudes downward from the lower surface of the body 41. The mounting portion 42B is supported by the body 41. The pin portion 42C protrudes in the -Y direction from the surface of the mounting portion 42B facing the -Y direction.

[0048] The pressing part 42A extends in the Z-axis direction. A part of the pressing part 42A is disposed in a notch 41E provided at the lower part of the body 41. The pressing part 42A extends in the -Z direction from the notch 41E. The pressing part 42A is disposed on the +Y side of the sewing needle 3A. The pressing part 42A is disposed in the feeding direction (+Y direction) with respect to the sewing needle 3A. The lower end part of the pressing part 42A contacts the seam SL formed in the fabric MS by the sewing needle 3A. The lower end part of the pressing part 42A is a flat surface. In the feeding operation, the pressing part 42A presses the seam SL from above and feeds it in the feeding direction. In the forward path (feeding operation) of the feeding foot 32, the pressing part 42A sandwiches the seam SL together with a part of the lower feed 61 and feeds it in the feeding direction.

[0049] The mounting part 42B is connected to the upper end part of the pressing part 42A. A pair of mounting parts 42B are provided in the X-axis direction. The mounting parts 42B are provided so as to branch from the +Z side end part of the pressing part 42A in the +X direction and the -X direction respectively. The mounting part 42B on the -X side extends from the +Z side end part of the pressing part 42A in the -X direction, bends, and then extends in the +Z direction. The mounting part 42B on the +X side extends from the +Z side end part of the pressing part 42A in the +X direction, bends, and then extends in the +Z direction.

[0050] The body 41 has a center guide part 41D for guiding the center member 42 in the vertical direction. The center guide part 41D is a guide groove in which the mounting part 42B is disposed. The center guide part 41D extends in the Z-axis direction. A pair of center guide parts 41D are provided in the X-axis direction. The mounting part 42B on the -X side is disposed inside the center guide part 41D on the -X side, and the mounting part 42B on the +X side is disposed inside the center guide part 41D on the +X side. A block part 41G of the body 41 is disposed between the pair of center guide parts 41D.

[0051] The pin part 42C is columnar. The pin part 42C protrudes in the -Y direction from the surface of the mounting part 42B facing the -Y direction. One pin part 42C is provided on each of the pair of mounting parts 42B.

[0052] The side member 43 is movable in the vertical direction with respect to the body 41. A pair of side members 43 are provided. The pair of side members 43 are arranged on both sides of the center member 42 in the X-axis direction. One side member 43 is arranged on the -X side of the center member 42. The other side member 43 is arranged on the +X side of the center member 42. The side member 43 protrudes downward from the body 41. The side member 43 has a pressing portion 43A, a mounting portion 43B, a pin portion 43C, and a feed tooth 43D. The pressing 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 portion 43A protrudes downward from the lower surface of the body 41. The mounting portion 43B is supported by the 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 tooth 43D is provided on the lower surface of the pressing portion 43A.

[0053] The pressing portion 43A extends in the -Y direction toward the -Z direction. The pressing portions 43A are arranged on both sides of the pressing portion 42A in the X-axis direction. The pair of pressing portions 43A are arranged on the -Y side of the pressing portion 42A. The lower end portion of the pressing portion 43A contacts the fabric MS. The feed tooth 43D is provided on the lower surface of the pressing portion 43A. The feed tooth 43D contacts the fabric MS. In the feeding operation, the pressing portion 43A presses the fabric MS from above and feeds it in the feeding direction. In the forward path (feeding operation) of the feed foot 32, the pressing portion 43A sandwiches the fabric MS together with a part of the downward feed 61 and feeds it in the feeding direction.

[0054] The mounting portion 43B is connected to the upper end portion of the pressing portion 43A. In the -X side side member 43, the mounting portion 43B extends in the -X direction from the +Z side end portion of the pressing portion 43A and then extends in the +Z direction after bending. In the +X side side member 43, the mounting portion 43B extends in the +X direction from the +Z side end portion of the pressing portion 43A and then extends in the +Z direction after bending.

[0055] The 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 in which the mounting portions 43B are disposed. 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.

[0056] The pin portion 43C is cylindrical. The pin portion 43C protrudes in the -Y direction from the surface of the mounting portion 43B facing the -Y direction. The pin portion 43C is provided one by one on each of the pair of mounting portions 43B.

[0057] The cover 44 is fixed to the end surface 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 facing the support portion 41B, a central recess 44A into which the block portion 41G is inserted and a pair of accommodation recesses 44B in which the rotating body 46 is accommodated are provided. The outer shape of the cover 44 is rectangular. Openings 44C are provided at each of the four corners of the cover 44.

[0058] The screw 45 fixes the support portion 41B and the cover 44. After being inserted into the opening 44C of the cover 44, the screw 45 is inserted into a screw hole 41H provided in the support portion 41B. The support portion 41B and the cover 44 are fixed by the engagement of the thread of the screw 45 and the thread groove of the screw hole 41H. In the embodiment, the support portion 41B and the cover 44 are fixed by four screws 45.

[0059] 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 accommodation recess 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.

[0060] 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 arranged in the X-axis direction. The rotating body 46 on the -X side connects the mounting portion 42B on the -X side and the mounting portion 43B on the -X side. The rotating body 46 on the +X side connects the mounting portion 42B on the +X side and the mounting portion 43B on the +X side.

[0061] The mounting portion 42B of the center member 42 is attached to 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 attached to 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.

[0062] The rotating body 46 has a first concave portion 46A and a second concave portion 46B. Each of the first concave portion 46A and the second concave portion 46B is provided so as 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 portion of the rotating body 46 is the first concave portion 46A provided on the rotating body 46. The second portion of the rotating body 46 is the second concave portion 46B provided on the rotating body 46.

[0063] The pin portion 42C provided on the mounting portion 42B which is the upper part of the center member 42 is arranged inside the first concave portion 46A, whereby the mounting portion 42B of the center member 42 is attached to the rotating body 46. The pin portion 43C provided on the mounting portion 43B which is the upper part of the side member 43 is arranged inside the second concave portion 46B, whereby the mounting portion 43B of the side member 43 is attached to the rotating body 46.

[0064] In the rotating body 46 on the -X side, the first concave portion 46A is arranged on the +X side of the second concave portion 46B. The pin portion 42C of the mounting portion 42B on the -X side is arranged 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 arranged in the second concave portion 46B of the rotating body 46 on the -X side.

[0065] In the rotating body 46 on the +X side, the first recess 46A is arranged on the -X side of the second recess 46B. In the first recess 46A of the rotating body 46 on the +X side, the pin portion 42C of the mounting portion 42B on the +X side is arranged. In the second recess 46B of the rotating body 46 on the +X side, the pin portion 43C of the mounting portion 43B on the +X side is arranged.

[0066] The side member 43 is interlocked with the center member 42. The side member 43 moves in a direction opposite to the moving direction of the center member 42. When the center member 42 moves upward, the side member 43 moves downward. When the center member 42 moves downward, the side member 43 moves upward. When the side member 43 moves downward, the center member 42 moves upward. When the side member 43 moves upward, the center member 42 moves downward.

[0067] When the center member 42 moves upward with respect to the body 41, the rotating body 46 connected to the center member 42 via the pin portion 42C rotates in the forward direction. When the rotating body 46 rotates in the forward direction, the side member 43 connected to the rotating body 46 via the pin portion 43C moves downward.

[0068] When the center member 42 moves downward with respect to the body 41, the rotating body 46 connected to the center member 42 via the pin portion 42C rotates in the reverse direction. When the rotating body 46 rotates in the reverse direction, the side member 43 connected to the rotating body 46 via the pin portion 43C moves upward.

[0069] As shown in FIG. 5, a gap D in the X-axis direction is provided between the pressing portions 43A of the pair of side members 43. The center member 42 is disposed in the region of the gap D. Further, as shown in FIG. 4, the feed foot 32 is attached to the upper feed bar 31 such that the sewing needle 3A is disposed between the pair of side members 43 in the X-axis direction. The sewing needle 3A is disposed in the region of the gap D between the pair of side members 43 and at the position in the -Y direction of the center member 42. FIG. 5 shows the needle drop position P of the sewing needle 3A. The sewing needle 3A passes vertically through the needle drop position P. The center member 42 is disposed on a straight line extending in the +Y direction from the needle drop position P (sewing needle 3A).

[0070] As shown in FIG. 5, when the sewing operation is performed by the sewing needle 3A while feeding the fabric MS in the +Y direction, a seam SL extending in the +Y direction from the needle drop position P is formed in the fabric MS. The center member 42, together with the lower feed 61 of the lower feed mechanism 6, presses and clamps the formed portion of the seam SL. Thereby, the center member 42 has a function of pressing so that the upper thread UT of the formed portion of the seam SL is not pulled back along with the vertical movement of the sewing needle 3A and the feed movement of the fabric MS at the needle drop position P. That is, the upper thread UT is supplied to the sewing needle 3A by pulling out a new portion of the upper thread UT from the balance 4 side (a thread supply source set on an upper thread stand not shown) by the tension acting on the upper thread UT, and is used for forming the seam SL. At this time, the tension also acts on the portion of the upper thread UT that has already formed the seam SL. When the upper thread UT of the portion of the seam SL is pulled out, it causes sewing shrinkage and the like. Therefore, the center member 42 presses the formed seam SL to suppress the upper thread UT from being pulled out from the seam SL side.

[0071] In FIG. 4, a pressing portion 17A of the fabric presser 17 is disposed in a region of the interval D between a pair of side members 43 (see FIG. 5). Although not shown, the pressing portion 17A of the fabric presser 17 is provided with a through hole for passing the sewing needle 3A and a through hole for passing the center member 42, respectively. Therefore, the sewing needle 3A and the feed foot 32 operate without interfering with the fabric presser 17.

[0072] In the embodiment, since each of the center member 42 and the side members 43 is movably attached to the body 41, in the feeding operation, it is possible to suppress the center member 42 from moving away from the seam SL or the side members 43 from moving away from the fabric MS.

[0073] As shown in FIG. 7, when there is no seam SL in the fabric MS, the feed foot 32 presses the fabric MS from above, so that the lower ends of the center member 42 and the side members 43 come into contact with the fabric MS, respectively.

[0074] As shown in FIG. 8, when there is a seam SL in the fabric MS, when the lower end of the center member 42 contacts the seam SL so as to press the seam SL from above, the center member 42 moves upward with respect to the body 41. When the center member 42 moves upward, the rotating body 46 rotates forward, so that the side members 43 move downward, and the lower ends of the side members 43 come into contact with the fabric MS so as to press the fabric MS from above.

[0075] Based on the protruding amount of the seam SL from the fabric MS, the upward movement amount of the center member 42 with respect to the body 41 is determined. When the protruding amount of the seam SL from the fabric MS is small, the upward movement amount of the center member 42 is small. When the protruding amount of the seam SL from the fabric MS is large, the upward movement amount of the center member 42 with respect to the body 41 is large.

[0076] The side member 43 is interlocked with the center member 42. The side member 43 moves in a direction opposite to the moving direction of the center member 42. The amount of movement of the center member 42 relative to the body 41 and the amount of movement of the side member 43 relative to the body 41 correspond one-to-one. The greater the upward movement amount of the center member 42, the greater the downward movement amount of the side member 43. The smaller the upward movement amount of the center member 42, the smaller the downward movement amount of the side member 43.

[0077] When the center member 42 presses the seam SL from above, the side member 43 is interlocked with the center member 42 so as to press the fabric MS from above. As shown in FIG. 8, in the feeding operation, since the center member 42 moves upward and the side member 43 moves downward, the center member 42 comes into sufficient contact with the seam SL and the side member 43 comes into sufficient contact with the fabric MS. In a state where the center member 42 is in sufficient contact with the seam SL and the side member 43 is in sufficient contact with the fabric MS, the feed foot 32 performs a feeding operation, so that a decrease in the feeding force of the fabric MS by the feed foot 32 is suppressed.

[0078] As shown in FIG. 8, when the center member 42 moves upward by a predetermined height with respect to the body 41, the lower end surface 41Gt of the block portion 41G and the upper end surface 42At of the pressing portion 42A come into contact. Due to the contact between the lower end surface 41Gt of the block portion 41G and the upper end surface 42At of the pressing portion 42A, the center member 42 is restricted from moving upward relative to the body 41 by more than the predetermined height. The lower end surface 41Gt of the block portion 41G functions as a stopper portion that restricts the center member 42 from moving upward relative to the body 41 by more than the predetermined height.

[0079] As described above, the upward feed path is composed of an outward path that feeds the fabric MS in the feed direction (+Y direction) and a return path that returns from the fabric MS to the feed start position. In the outward path, the feed foot 32 moves in the feed direction (+Y direction) from the feed start position to the feed end position while in contact with the seam SL (in a state of descending in the -Z direction). In the return path, the feed foot 32 returns in the -Y direction from the feed end position to the feed start position while being separated from the fabric MS in the +Z direction. In the return path, when the feed foot 32 rises so as to be separated from the fabric MS, due to the action of gravity, the side member 43 moves downward. When the side member 43 moves downward, the center member 42 moves upward. Since the lower end surface 41Gt of the block portion 41G restricts the center member 42 from moving upward beyond a predetermined height, it is possible to suppress the side member 43 from protruding too far downward from the body 41 or falling from the body 41. In the return path of the upward feed path, it is possible to suppress the side member 43 from contacting the fabric MS.

[0080] The feed foot 32 that has moved to the feed start position descends so as to approach the fabric MS. When the feed foot 32 approaches the fabric MS, the center member 42 first contacts the seam SL and moves upward with respect to the body 41, and the side member 43 moves downward with respect to the body 41 so as to contact the fabric MS. The feed foot 32 can perform the feed operation in a state where the center member 42 is in sufficient contact with the seam SL and the side member 43 is in sufficient contact with the fabric MS.

[0081] [Effect] As described above, according to the embodiment, the sewing machine 1 includes a needle bar 3 that holds the sewing needle 3A and is driven in the vertical direction, and an upper feed mechanism 5 that operates in conjunction with the operation of the needle bar 3 and contacts the fabric MS from above to feed the fabric MS in the feeding direction. The upper feed mechanism 5 includes a swingable upper feed bar 31 and a feed foot 32 provided at the lower end of the upper feed bar 31. The feed foot 32 includes a body 41 attached to the lower end of the upper feed bar 31, a center member 42 that protrudes downward from the body 41 and is movable in the vertical direction with respect to the body 41 and contacts the seam SL formed in the fabric MS by the sewing needle 3A, and a pair of side members 43 that protrude downward from the body 41 and are movable in the vertical direction with respect to the body 41 and have feed teeth 43D that contact the fabric MS and are disposed on both sides of the center member 42. When the center member 42 moves upward, the side members 43 move downward. When the center member 42 moves downward, the side members 43 move upward.

[0082] According to the embodiment, when the feed foot 32 descends so as to approach the fabric MS at the feed start position in the feeding operation, based on the protruding amount of the seam SL from the fabric MS, the center member 42 that contacts the seam SL moves upward with respect to the body 41, and the side members 43 move downward with respect to the body 41 so as to contact the fabric MS in conjunction with the center member 42. The feed foot 32 can perform the feeding operation in a state where the center member 42 sufficiently contacts the seam SL and the side members 43 sufficiently contact the fabric MS. Thereby, a decrease in the feeding force of the fabric MS by the feed foot 32 is suppressed.

[0083] For example, when double-ring sewing a thin and hard fabric MS such as an airbag with a thick thread, the protruding amount of the seam SL from the fabric MS may increase. When the protruding amount of the seam SL from the fabric MS is large, the side member 43 may not sufficiently contact the fabric MS when the center member 42 contacts the seam SL. According to the embodiment, according to the protruding amount of the seam SL from the fabric MS, the center member 42 that contacts the seam SL moves upward with respect to the body 41, and the side member 43 moves downward with respect to the body 41 so as to contact the fabric MS in conjunction with the center member 42. Therefore, the center member 42 can sufficiently contact the seam SL, and the side member 43 can also sufficiently contact the fabric MS. The feed foot 32 can feed the fabric MS in the feed direction with a high feed force in a state where the center member 42 sufficiently contacts the seam SL and the side member 43 sufficiently contacts the fabric MS.

[0084] The feed foot 32 has a rotating body 46 rotatably supported by the body 41. The center member 42 has a pin portion 42C disposed in a first recess 46A on one side of the rotation axis of the rotating body 46. The side member 43 has a pin portion 43C disposed in a second recess 46B on the other side of the rotation axis of the rotating body 46. The rotating body 46 functions as a seesaw. When the center member 42 contacts the seam SL and moves upward, the rotating body 46 rotates, and due to the rotation of the rotating body 46, the pair of side members 43 move downward.

[0085] The body 41 has a center guide portion 41D that guides the center member 42 in the vertical direction and a side guide portion 41F that guides the side member 43 in the vertical direction. From this, each of the center member 42 and the side member 43 can move smoothly in the vertical direction.

[0086] The body 41 has a lower end surface 41Gt that restricts the center member 42 from moving upward relative to the body 41 by more than a predetermined height. As a result, in the return path of the upper feed track, it is suppressed that the side member 43 protrudes downward too much from the body 41 or drops from the body 41. In the return path of the upper feed track, it is suppressed that the side member 43 contacts the fabric MS.

Explanation of Signs

[0087] 1... Sewing machine, 2... Sewing machine body, 2A... First arm, 2B... Bed, 2C... Second arm, 2D... Head, 3... Needle bar, 3A... Sewing machine needle, 4... Balance, 5... Upper feed mechanism, 6... Lower feed mechanism, 7... Needle hole, 8... Needle plate, 8A... Opening, 9... Looper, 10... Upper thread conditioner, 11... Lower thread conditioner, 12... Actuator, 13... Power transmission device, 13A... Arm shaft, 13B... Bed shaft, 13C... Looper 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 rod, 15... Upper thread guide, 16... Lower thread guide, 17... Fabric presser, 17A... Presser part, 18... Biasing mechanism, 18A... Compression coil spring, 31... Upper feed bar, 32... Feed foot, 33... Support shaft, 41... Body, 41A... Fixed part, 41B... Support part, 41C... Insertion hole, 41D... Center guide part, 41E... Notch, 41F... Side guide part, 41G... Block part, 41Gt... Lower end surface (stopper part), 41H... Thread hole, 42... Center member, 42A... Presser part, 42At... Upper end surface, 42B... Mounting part, 42C... Pin part, 43... Side member, 43A... Presser part, 43B... Mounting part, 43C... Pin part, 43D... Feed teeth, 44... Cover, 44A... Central recess, 44B... Accommodation recess, 44C... Opening, 45... Screw, 46... Rotating body, 46A... First recess, 46B... Second recess, 61... Lower feed, 62... Feed table, AX... Axis of rotation, D... Interval, LT... Lower thread, MS... Fabric, P... Needle drop position, SL... Seam, UT... Upper thread.

Claims

1. A needle bar that holds a sewing needle and is driven vertically, and an upper feed mechanism that is interlocked with the operation of the needle bar, contacts the fabric from above, and feeds the fabric in the feeding direction. The upper feed mechanism includes a swinging upper feed bar and a feed foot provided at the lower end of the upper feed bar. The feed foot has a body attached to the lower end of the upper feed bar, a center member that protrudes downward from the body, is movable vertically with respect to the body, and contacts the seam formed in the fabric by the sewing needle, and a pair of side members that protrude downward from the body, are movable vertically with respect to the body, have feed teeth that contact the fabric, and are disposed on both sides of the center member. When the center member moves upward, the side members move downward, and when the center member moves downward, the side members move upward. A sewing machine.

2. The feed foot has a rotating body rotatably supported by the body, the center member is attached to a first portion on one side of the rotation axis of the rotating body, and the side member is attached to a second portion on the other side of the rotation axis of the rotating body. The sewing machine according to Claim 1.

3. The first portion is a first recess provided in the rotating body, the second portion is a second recess provided in the rotating body, the center member is attached to the rotating body by disposing a pin portion provided at the upper portion of the center member in the first recess, and the side member is attached to the rotating body by disposing a pin portion provided at the upper portion of the side member in the second recess. The sewing machine according to Claim 2.

4. The body has a center guide portion that guides the center member vertically, and a side guide portion that guides the side member vertically. The sewing machine according to Claim 1.

5. The body has a stopper portion that restricts the center member from moving upward with respect to the body beyond a predetermined height. The sewing machine according to Claim 1.

Images