Sewing machine

Abstract

A sewing machine (1) comprises: a needle bar (6) that holds a sewing machine needle (4) and that moves vertically to lower the needle onto an object to be sewn (MS); under the needle bar (6), a needle plate (7) that supports the object to be sewn (MS) from below; a lower feeding mechanism (9) that feeds, from a lower side, the object to be sewn (MS) supported by the needle plate (7); and hook (13) that is disposed below the needle plate (7) and supplies bobbin thread to the object to be sewn (MS). The lower feeding mechanism (9) includes: a feeding tooth (31) that feeds and moves the object to be sewn (MS); a feeding tooth base (32) that holds the feeding tooth (31) and moves along a feeding track; and a receiving member (33) that is provided on the feeding tooth base (32) and is disposed laterally with respect to a needle lowering path of the sewing machine needle (4). The receiving member (33) includes a receiving surface (34) that faces the needle lowering path (NP) and can be positionally adjusted in an adjustment direction approaching or separating from the needle lowering path (NP).

Description

sewing machine

[0001] The present disclosure relates to sewing machines.

[0002] Patent Document 1 discloses a sewing machine in which a sewing needle penetrates the sewing object while the sewing object is fed by a feed dog, and a horizontal shuttle is used to entangle the upper thread with the lower thread to perform sewing.

[0003] Japanese Patent No. 4913575

[0004] When sewing thick sewing objects or hard sewing objects such as leather or resin, the sewing machine needle may bend during needle penetration. If the sewing machine needle is bent, the needle tip position after penetrating the sewing object will deviate from the correct position. Therefore, a bent sewing machine needle can cause poor stitching such as skipped stitches in some parts of the stitches, or thread breakage. Here, a skipped stitch refers to a stitch not being formed because the bobbin thread is not entangled with the upper thread. There is a need to achieve stable sewing even under conditions where bending of the sewing machine needle occurs.

[0005] An object of the present disclosure is to achieve stable sewing even under conditions that may cause bending of the sewing machine needle.

[0006] According to one aspect of the present disclosure, there is provided a sewing machine comprising: a needle bar that holds a sewing needle and moves up and down to drop the needle into an object to be sewn; a needle plate that supports the object to be sewn from below below the needle bar; a bottom feed mechanism that feeds the object to be sewn supported by the needle plate from below; and a shuttle that is arranged below the needle plate and supplies a bobbin thread to the object to be sewn; the bottom feed mechanism includes a feed dog that feeds and moves the object to be sewn; a feed dog base that holds the feed dog and moves along a feed orbit; and a receiving member that is provided on the feed dog base and is arranged to the side of the needle drop path of the sewing needle; and the receiving member has a receiving surface that faces the needle drop path and can be adjusted in a direction to move closer to or away from the needle drop path.

[0007] According to the present disclosure, stable sewing can be achieved even under conditions that would cause bending of the sewing machine needle.

[0008] FIG. 1 is a perspective view of a sewing machine according to an embodiment, as seen from the upper left rear. FIG. 2 is an enlarged perspective view of the interior of a sewing machine frame according to an embodiment, as seen from the upper left rear. FIG. 3 is a schematic view illustrating the operation of a sewing needle and a shuttle. FIG. 4 is a schematic view illustrating feeding of the sewing machine. FIG. 5 is a perspective view of a bottom feed mechanism, as seen from the upper left rear. FIG. 6 is a perspective view of a bottom feed mechanism, as seen from the upper right rear. FIG. 7 is a plan view showing a receiving member attached to a feed dog base. FIG. 8 is a right side view showing the bottom feed mechanism and the sewing needle. FIG. 9 is a cross-sectional view of the bottom feed mechanism, the sewing needle, and the shuttle, as seen from the rear to the front. FIG. 10 is a schematic view showing a comparative example in which a receiving member is not provided. FIG. 11 is a schematic view showing this embodiment in which a receiving member is provided.

[0009] Hereinafter, an embodiment will be described with reference to the drawings. In this embodiment, an XYZ Cartesian coordinate system is set, and the positional relationships of each part will be described with reference to this XYZ Cartesian coordinate system. This XYZ Cartesian coordinate system is a relative direction set for the sewing machine 1 illustrated in FIGS. 1 to 11 . The direction parallel to the X axis within a predetermined plane is defined as the X-axis direction. The direction parallel to the Y axis within a predetermined plane, which is perpendicular to the X axis, is defined as the Y-axis direction. The direction parallel to the Z axis, which is perpendicular to the predetermined plane, is defined as the Z-axis direction. Furthermore, the direction of rotation or tilt around the X axis is defined as the θX direction. The direction of rotation or tilt around the Y axis is defined as the θY direction. The direction of rotation or tilt around the Z axis is defined as the θZ direction. Furthermore, the plane including the X axis and the Y axis will be referred to as the XY plane as appropriate. The plane including the X axis and the Z axis will be referred to as the XZ plane as appropriate. The plane including the Y axis and the Z axis will be referred to as the YZ plane as appropriate. The XY plane is parallel to the predetermined plane. The XY plane, the XZ plane, and the YZ plane are perpendicular to each other.

[0010] In this embodiment, the XY plane and the horizontal plane are parallel. The horizontal direction includes the front-to-rear direction and the left-to-right direction. Note that the above phrase "the XY plane and the horizontal plane are parallel" does not intend to limit the XY plane to being parallel to the horizontal plane. In the present disclosure, the XY plane may be inclined with respect to the horizontal plane. Furthermore, the X-axis direction is the front-to-rear direction. The Y-axis direction is the left-to-right direction. The Z-axis direction is the up-down direction. The +X direction is the forward direction, and the -X direction is the backward direction. The +Y direction is the leftward direction, and the -Y direction is the rightward direction. The +Z direction is the upward direction, and the -Z direction is the downward direction.

[0011] [Overview of Sewing Machine] Fig. 1 is a perspective view of a sewing machine 1 according to an embodiment, seen from the upper left rear. Fig. 1 illustrates only the main structure of the sewing machine 1, and omits details. In this embodiment, the sewing machine 1 is an industrial sewing machine. The sewing machine 1 is a so-called lock stitch sewing machine that forms seams by intertwining an upper thread and a bobbin thread. As shown in Fig. 1, the sewing machine 1 has a sewing machine frame 3.

[0012] The sewing machine frame 3 has an arm 3A, a bed 3B, a base 3C, and a head 3D. The arm 3A is long in the left-right direction of the sewing machine 1. The bed 3B is arranged below the arm 3A. The bed 3B is long in the left-right direction of the sewing machine 1. The bed 3B is arranged so as to face the arm 3A in the up-down direction. The base 3C is arranged so as to connect the right end of the arm 3A and the bed 3B. The base 3C is long in the up-down direction of the sewing machine 1. The head 3D is provided at the left end of the arm 3A. The head 3D is provided so as to protrude downward from the left end of the arm 3A.

[0013] 1, the sewing machine 1 includes a thread take-up lever 5, a needle bar 6, a needle plate 7, a presser foot 8, a thread tensioner, a lower feed mechanism 9, a sewing machine motor 10, a pulley 11, an upper feed mechanism 12, and a shuttle 13 (see FIG. 2). The sewing machine 1 also includes a controller that controls each part of the sewing machine 1, and a pedal and an operation panel that accept operational inputs to the sewing machine 1.

[0014] 2 is an enlarged perspective view of the interior of the sewing machine frame 3 according to this embodiment, as seen from the upper left rear. In FIG. 2, only the main structure is shown, and details are omitted.

[0015] As shown in FIGS. 1 and 2 , the needle bar 6 holds the sewing needle 4. The needle bar 6 holds the sewing needle 4 so that it is parallel to the Z-axis. The needle bar 6 moves back and forth in the vertical direction. The needle bar 6 is supported by the head 3D. The needle bar 6 moves up and down to make a needle entry into the sewing workpiece MS. The sewing needle 4 has a threading hole through which the upper thread UT (see FIG. 3 ) passes. The sewing needle 4 holds the upper thread UT on the inner surface of the threading hole. As the needle bar 6 moves back and forth in the vertical direction, the sewing needle 4 moves back and forth in the vertical direction while holding the upper thread UT. The needle bar 6 also moves back and forth in the front-to-back direction (X-axis direction) as well as up and down. The needle bar 6 moves in a trajectory linked to the operation of the bottom feed mechanism 9 and the top feed mechanism 12 by a combination of up and down and back-to-back movement. As the needle bar 6 moves, the sewing needle 4 moves in a predetermined needle feed trajectory in the XZ plane.

[0016] The thread take-up lever 5 (see Figure 1) supplies the upper thread UT to the sewing machine needle 4. The thread take-up lever 5 moves back and forth in the vertical direction. The thread take-up lever 5 is supported by the arm 3A. The thread take-up lever 5 moves back and forth in the vertical direction while holding the upper thread UT. The thread take-up lever 5 has a holding hole through which the upper thread UT passes. The thread take-up lever 5 holds the upper thread UT on the inner surface of the holding hole. By moving back and forth in the vertical direction, the thread take-up lever 5 pays out and pulls up the upper thread UT used to sew the sewing object MS. The thread tensioner applies tension to the upper thread UT supplied to the sewing machine needle 4 between the thread take-up lever 5 and the needle bar 6. The thread tensioner is supported by the head 3D.

[0017] The needle plate 7 is disposed below the needle bar 6. The needle plate 7 supports the sewing object MS from below. The needle plate 7 supports the sewing object MS below the needle bar 6. The sewing machine needle 4 held by the needle bar 6 and the needle plate 7 face each other. The needle plate 7 has an opening through which the feed dog 31 of the lower feed mechanism 9 can pass.

[0018] The presser foot 8 presses down on the sewing object MS supported by the needle plate 7 from above. The presser foot 8 is arranged at least partially around the sewing needle 4. The presser foot 8 is fixed to the lower end of the presser foot bar 8A (see FIG. 2). The presser foot bar 8A is supported by the head 3D. The presser foot bar 8A is movable in the vertical direction. The presser foot 8 is pressed down on the sewing object MS from above by the elastic force generated by a presser foot spring provided in the head 3D. The presser foot 8 has a pair of pressing pieces that branch off from the tip that comes into contact with the sewing object MS. One pressing piece is arranged in the +Y direction relative to the sewing needle 4, and the other pressing piece is arranged in the -Y direction relative to the sewing needle 4.

[0019] The bottom feed mechanism 9 is disposed below the needle plate 7. The bottom feed mechanism 9 feeds the sewing workpiece MS supported by the needle plate 7 from below. The bottom feed mechanism 9 includes a feed dog 31 and a feed dog base 32. The feed dog 31 feeds and moves the sewing workpiece MS forward. The feed dog 31 is disposed below the needle plate 7. The top surface of the feed dog 31 is formed with sawtooth teeth to increase frictional resistance with the sewing workpiece MS. The feed dog base 32 holds the feed dog 31. The feed dog base 32 moves (swings) in conjunction with the needle bar 6. The feed dog 31 moves along a predetermined feed orbit in conjunction with the movement of the feed dog base 32, and appears and disappears through an opening provided in the needle plate 7. When feeding the sewing workpiece MS, at least a portion of the feed dog 31 protrudes upward from the top surface of the needle plate 7 through the opening provided in the needle plate 7.

[0020] The upper feed 12 is disposed above the needle plate 7. The upper feed 12 feeds the sewing workpiece MS supported by the needle plate 7 from above. The upper feed 12 is disposed at least partially around the sewing machine needle 4. The upper feed 12 is located between a pair of pressure pieces provided at the tip of the presser foot 8. The upper feed 12 is fixed to the lower end of the upper feed rod 12A. The upper feed rod 12A is supported by the head 3D. The upper feed rod 12A moves (oscillates) in conjunction with the needle bar 6. The upper feed 12 moves in a predetermined upper feed orbit in conjunction with the movement of the upper feed rod 12A. The lower surface of the upper feed 12 is formed with sawtooth teeth to increase frictional resistance with the sewing workpiece MS.

[0021] The shuttle 13 supplies the lower thread to the sewing workpiece MS. The shuttle 13 is disposed below the feed dog 31. In this embodiment, the shuttle 13 is a so-called horizontal shuttle, with its rotation axis oriented in the Z-axis direction. In other words, the shuttle 13 is rotatable in the θZ direction. The shuttle 13 has an inner shuttle that stores a bobbin that holds the lower thread, and an outer shuttle that rotates in the θZ direction. The shuttle 13 is supported by a shuttle holder 14.

[0022] The sewing machine motor 10 (see FIG. 1) generates power to operate the needle bar 6, feed dog 31, top feed 12, and shuttle 13. The sewing machine motor 10 generates power to move the needle bar 6 along the needle feed orbit. The sewing machine motor 10 generates power to rotate the shuttle 13 in the θZ direction. The sewing machine motor 10 generates power to move the feed dog 31 along the feed orbit. The sewing machine motor 10 generates power to move the top feed 12 along the top feed orbit. The sewing machine motor 10 includes a pulse motor. The sewing machine motor 10 is supported on the right portion of the arm 3A.

[0023] The sewing machine motor 10 is connected to the needle bar 6, the feed dog 31, the top feed 12, and the shuttle 13 via a sewing machine power transmission mechanism. The sewing machine power transmission mechanism operates each of the needle bar 6, the feed dog 31, the top feed 12, and the shuttle 13 based on the power generated by the sewing machine motor 10. The sewing machine power transmission mechanism transmits the power generated by the sewing machine motor 10 to each of the needle bar 6, the feed dog 31, the top feed 12, and the shuttle 13.

[0024] Specifically, an upper shaft extending in the Y-axis direction is disposed inside arm 3A. Sewing machine motor 10 is connected to the -Y end of the upper shaft. The +Y end of the upper shaft is connected to needle bar 6 via a swing link mechanism disposed inside head 3D. Operation of sewing machine motor 10 rotates the upper shaft. Power generated by sewing machine motor 10 is transmitted to needle bar 6 via the upper shaft and swing link mechanism. Needle bar 6 and sewing machine needle 4 held by needle bar 6 reciprocate (swing) up and down and back and forth along a needle feed orbit based on the power generated by sewing machine motor 10.

[0025] The upper shaft is connected to the upper feed rod 12A via a swing link mechanism disposed inside the head 3D. Power generated by the sewing machine motor 10 is transmitted to the upper feed rod 12A via the upper shaft and the swing link mechanism. The upper feed rod 12A and the upper feed 12 held by the upper feed rod 12A reciprocate (swing) up and down and back and forth on the upper feed track based on the power generated by the sewing machine motor 10.

[0026] A timing belt extending in the Z-axis direction is disposed inside the base 3C. Furthermore, a bed shaft 20 (see FIG. 2) extending in the Y-axis direction is disposed inside the bed 3B. Pulleys are disposed on both the upper shaft and the bed shaft 20. A timing belt is wound around the pulley disposed on the upper shaft and the pulley disposed on the bed shaft 20. The upper shaft and the bed shaft 20 are connected via the timing belt.

[0027] 2, the bed shaft 20 is connected via a bevel gear to a shuttle shaft that is provided on the shuttle holder 14 and extends in the Z-axis direction so as to transmit power. Operation of the sewing machine motor 10 causes the upper shaft and the bed shaft 20 to rotate. Power generated by the sewing machine motor 10 is transmitted to the shuttle 13 via the upper shaft, timing belt, bed shaft 20, and shuttle shaft. As a result, the shuttle 13 rotates in the θZ direction in synchronization with the movement of the needle bar 6 so that the bobbin thread is supplied to the sewing workpiece MS.

[0028] A pair of lower shafts 21A and 21B extending in the Y-axis direction are disposed inside the bed 3B. The lower shafts 21A and 21B are each connected to the upper shaft via a cam mechanism that passes through the base 3C. The lower shaft 21A is disposed on the front side (+X direction) of the bed 3B. The lower shaft 21A is connected to the front end of the feed dog table 32 via an arm portion 22A extending in the radial direction. The lower shaft 21B is disposed on the rear side (-X direction) of the bed 3B. The lower shaft 21B is connected to the rear end of the feed dog table 32 via an arm portion 22B extending in the radial direction. Operation of the sewing machine motor 10 rotates the upper shaft, and the lower shafts 21A and 21B each undergo periodic motion via the cam mechanism. Power generated by the sewing machine motor 10 is transmitted to the feed dog table 32 via the upper shaft, the cam mechanism, the lower shaft 21A, and the lower shaft 21B. As a result, feed dog table 32 swings in synchronization with the movement of needle bar 6. As feed dog table 32 swings, feed dog 31 moves (swings) back and forth in the up-down direction and the back-and-forth direction on the feed track.

[0029] With this configuration, the sewing machine 1 sews the sewing object MS through cooperation between the sewing needle 4 held by the needle bar 6 and the shuttle 13. The sewing machine 1 feeds the sewing object MS forward (in the +X direction) through cooperation between the upper feed 12, the feed dog 31, and the sewing needle 4.

[0030] FIG. 3 is a schematic diagram illustrating the operation of the sewing needle 4 and the shuttle 13. During sewing, the sewing needle 4 holding the upper thread UT descends in the -Z direction, penetrating the sewing object MS (see FIG. 1) from above. The sewing needle 4 descends to the bottom dead center position in the Z axis direction and then ascends. When the sewing needle 4 begins to ascend, the upper thread UT loosens between the threading hole of the sewing needle 4 and the sewing object MS, forming a loop in the upper thread UT. The shuttle 13 rotates in the Zθ direction in conjunction with the movement of the sewing needle 4, and the point 13A of the outer shuttle enters and captures the loop in the upper thread UT. The shuttle 13 continues to rotate while capturing the loop in the upper thread UT, causing the inner shuttle to pass through the loop. As a result, the shuttle 13 inserts the bobbin thread (not shown) pulled out of the inner shuttle into the loop in the upper thread UT and entangles it, forming a stitch.

[0031] FIG. 4 is a schematic diagram illustrating the feed of the sewing machine 1. During sewing, the feed dog 31 oscillates on the bottom feed orbit, the top feed mechanism 12 oscillates on the top feed orbit, and the needle bar 6 (sewing needle 4) oscillates on the needle feed orbit within the XZ plane. The bottom feed orbit, top feed orbit, and needle feed orbit are circular orbits along the feed direction (X-axis direction), e.g., elliptical orbits. The top feed mechanism 12 and feed dog 31 sandwich the sewing workpiece MS from above and below and move in the feed direction (+X direction), thereby moving the sewing workpiece MS in the feed direction. At this time, the needle bar 6 (sewing needle 4) moves in the feed direction (+X direction) in conjunction with the top feed mechanism 12 and feed dog 31, with the sewing needle 4 remaining pierced through the sewing workpiece MS. In this way, the sewing machine 1 is an integrated feed sewing machine in which the feed dog 31 of the bottom feed mechanism 9, the top feed mechanism 12, and the needle bar 6 operate on mutually linked feed orbits. The integrated feed is a feed method that can increase the feed force of the sewing object MS, and is suitable for sewing a thick sewing object MS.

[0032] The controller controls the sewing machine motor 10. The controller has a processor such as a CPU (Central Processing Unit), a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), and an input / output interface including an input / output circuit that can input and output signals and data.

[0033] The pedal is operated by an operator of the sewing machine 1. The operator operates the pedal with his foot. An operation signal generated by operating the pedal is sent to the controller. The sewing machine motor is driven or stopped based on the operation state of the pedal. The operation panel includes a flat panel display and a touch panel. The operation panel is operated by an operator of the sewing machine 1. The operation panel is provided on at least a part of the sewing machine frame 3. The operator operates the operation panel with his finger to make settings related to the operation of the sewing machine 1.

[0034] [Bottom Feed Mechanism] Next, a detailed description will be given of the structure of the bottom feed mechanism 9. Fig. 5 is a perspective view of the bottom feed mechanism 9 as seen from the upper left rear. Fig. 6 is a perspective view of the bottom feed mechanism 9 as seen from the upper right rear.

[0035] As shown in Figures 5 and 6, the feed dog 31 is fixed to the upper end of the feed dog table 32 at the center in the X-axis direction. The feed dog 31 has a fixed portion 31A attached to the feed dog table 32, a wall portion 31B rising upward from the fixed portion 31A, and a top surface portion 31C provided at the upper end of the wall portion 31B and contacting the sewing workpiece MS. The wall portion 31B is located at the right end of the fixed portion 31A. The wall portion 31B has an upright plate-like shape along the XZ plane. The top surface portion 31C protrudes to the right (-Y direction) from the upper end of the wall portion 31B. The top surface portion 31C is provided with saw-tooth teeth 31D and a needle hole 31E. The needle hole 31E penetrates the top surface portion 31C vertically at a position offset to the right (-Y direction) from the wall portion 31B. When the sewing needle 4 descends, the sewing needle 4 penetrates the sewing object MS and passes through the needle eye 31E.

[0036] The feed dog table 32 is a plate-like member extending along the front-rear direction of the lower feed mechanism 9. A connecting portion 32A with the lower shaft 21A (arm portion 22A) is provided at the front end of the feed dog table 32. A connecting portion 32B with the lower shaft 21B (arm portion 22B) is provided at the rear end of the feed dog table 32. A holding portion 32C that holds the feed dog 31 is provided between the connecting portions 32A and 32B in the front-rear direction. A fixing portion 31A of the feed dog 31 is attached to the upper surface of the holding portion 32C.

[0037] In this embodiment, as shown in FIG. 6 , the bottom feed mechanism 9 includes a receiving member 33. The receiving member 33 is provided on the feed dog table 32. The receiving member 33 is provided on a side surface of the holder 32C of the feed dog table 32. The receiving member 33 is disposed laterally with respect to the needle path NP of the sewing machine needle 4. The receiving member 33 is disposed directly below the feed dog 31. The needle path NP is the path (trajectory) of movement of the sewing machine needle 4 relative to the bottom feed mechanism 9. The needle path NP is a path along the Z-axis direction that passes through the needle eye 31E. The receiving member 33 has a receiving surface 34 that faces the needle path NP. The receiving surface 34 is a side surface of the receiving member 33 on the right (-Y) side. The position of the receiving surface 34 can be adjusted in a direction that moves closer to or further away from the needle path NP. In this embodiment, the adjustment direction of the receiving surface 34 is the Y-axis direction.

[0038] Figure 7 is a plan view showing the receiving member 33 attached to the feed dog head 32. Figure 7 shows the state in which the feed dog 31 has been removed from the feed dog head 32. The receiving member 33 has a first portion 33A, a second portion 33B, and a third portion 33C. The receiving member 33 has a roughly inverted U-shape with the first portion 33A, the second portion 33B, and the third portion 33C. The receiving member 33 is a single article in which the first portion 33A, the second portion 33B, and the third portion 33C are integrally formed. The receiving member 33 is made of metal, for example, spring steel.

[0039] The first portion 33A forms the left side (+Y side) of the receiving member 33 and extends linearly in the front-to-rear direction. The first portion 33A is fixed to the feed dog carriage 32. Two through-holes (non-threaded holes) are formed in the first portion 33A for inserting mounting screws 35. The mounting screws 35 inserted into each through-hole are attached to threaded holes provided in the side of the holding portion 32C of the feed dog carriage 32. The receiving member 33 is fastened to the side of the holding portion 32C at the first portion 33A by the two mounting screws 35. Furthermore, the first portion 33A has an insertion hole 33D between the two through-holes for inserting an adjustment member 36 (see FIG. 5 ), which will be described later. The first portion 33A connects to the third portion 33C at its front end.

[0040] The second portion 33B forms the right side (-Y side, needle path NP side) of the receiving member 33 and extends linearly in the front-to-rear direction. A receiving surface 34 is formed on the second portion 33B. That is, the outer surface on the right side (-Y side) of the second portion 33B is the receiving surface 34. The second portion 33B extends rearward (in the -X direction) from the third portion 33C. The second portion 33B extends at least to a position rearward (in the -X direction) of the needle path NP. That is, the receiving surface 34 is formed in a range from a position on the +X side of the needle path NP to a position on the -X side of the needle path NP. In the example shown in FIG. 7, the length of the second portion 33B in the X direction is shorter than the length of the first portion 33A in the X direction.

[0041] The third portion 33C forms the front (+X side) side surface of the receiving member 33 and extends linearly in the left-right direction. The third portion 33C connects the first portion 33A and the second portion 33B. The left end of the third portion 33C connects to the first portion 33A, and the right end of the third portion 33C connects to the second portion 33B.

[0042] FIG. 8 is a right side view showing the bottom feed mechanism 9 and the sewing needle 4. The receiving surface 34 faces the side of the sewing needle 4 passing through the needle path NP in the Y-axis direction. The receiving member 33 moves up and down and back and forth along the feed track together with the feed dog 31 and the feed dog table 32. The receiving member 33 maintains a state of facing the side of the sewing needle 4 in the Y-axis direction near the bottom dead center of the sewing needle 4. As shown in FIG. 7 , the receiving surface 34 is positioned away from the needle path NP in the +Y direction. When the sewing needle 4 moves normally along the needle path NP, the receiving surface 34 does not contact the sewing needle 4. If the sewing needle 4 bends toward the feed dog 31 (i.e., in the +Y direction) during sewing, the receiving surface 34 comes into contact with the bent sewing needle 4. This allows the receiving surface 34 to restrict the sewing needle 4 from bending more than the allowable amount. The "bending" of the sewing needle 4 referred to here means a very small deformation that allows the sewing needle 4 to be inserted into and removed from the needle eye 31E, and is within a range that allows sewing to continue.

[0043] As shown in FIG. 7 , in this embodiment, the distance CL between the receiving surface 34 and the needle path NP (i.e., the sewing machine needle 4) in the adjustment direction (Y-axis direction) is adjustable depending on the position of the receiving surface 34. As described above, the receiving member 33 is formed from spring steel or the like, and has a spring property that allows the second portion 33B to be displaced in the adjustment direction (Y-axis direction) by elastic deformation. The lower feed mechanism 9 includes an adjustment member 36 that displaces the second portion 33B in the adjustment direction (Y-axis direction). The receiving member 33 can adjust the position of the receiving surface 34 by displacing the second portion 33B in the adjustment direction (Y-axis direction) using the adjustment member 36.

[0044] The adjustment member 36 is a feed screw attached to the feed dog head 32 so as to abut against the second portion 33B and is provided so as to be movable forward and backward in the adjustment direction (Y-axis direction). As shown in FIG. 5, the adjustment member 36 is inserted into a threaded hole formed in the holding portion 32C of the feed dog head 32 via the insertion hole 33D of the first portion 33A. The threaded hole formed in the holding portion 32C penetrates the holding portion 32C in the Y-axis direction. As shown in FIGS. 6 and 7, the adjustment member 36 penetrates the holding portion 32C in the -Y direction and abuts against the side surface of the second portion 33B on the +Y side. The adjustment member 36 presses the second portion 33B in the -Y direction.

[0045] FIG. 7 shows the adjustment member 36 in the standard position. In its natural state, when not pressed by the adjustment member 36, the second portion 33B is bent toward the +Y side from the standard position shown in FIG. 7. The second portion 33B is positioned in the position shown in FIG. 7 by being pushed in the -Y direction by the adjustment member 36 to the standard position. By turning the adjustment member 36 in the screw hole of the holding portion 32C and feeding the adjustment member 36 in the -Y direction, the second portion 33B deforms in the -Y direction from the standard position, displacing the receiving surface 34 in the -Y direction. As a result, the distance CL between the receiving surface 34 and the needle drop path NP decreases. Conversely, when the adjustment member 36 is fed in the +Y direction from the standard position, the second portion 33B returns to its original position in the +Y direction due to its spring property, displacing the receiving surface 34 in the +Y direction. As a result, the distance CL between the receiving surface 34 and the needle drop path NP increases.

[0046] 9 is a cross-sectional view of the lower feed mechanism 9, the sewing machine needle 4, and the shuttle 13, seen from the rear to the front. The position of the receiving surface 34 can be adjusted between a position closer to the needle path NP than the side surface 31F of the wall portion 31B on the needle path NP side, and a position farther from the needle path NP than the side surface 31F of the feed dog 31. In other words, the receiving surface 34 can be displaced to a position further in the -Y direction than the side surface 31F. The receiving surface 34 can also be displaced to a position further in the +Y direction than the side surface 31F.

[0047] Incidentally, the sewing needle 4 may bend in the -Y direction during sewing. Therefore, as shown in FIG. 3 , the shuttle 13 has a needle receiver 13B that comes into contact with the bent needle 4 when it bends in the -Y direction, preventing it from bending more than the allowable amount. The needle receiver 13B is provided on the outer shuttle of the shuttle 13 and rotates together with the point 13A. The receiving surface 34 of the receiving member 33 faces the needle receiver 13B of the shuttle 13 in the adjustment direction (Y-axis direction). The receiving surface 34 is located on the +Y side of the needle path NP, and the needle receiver 13B is located on the -Y side of the needle path NP. Therefore, in the sewing machine 1, whether the sewing needle 4 bends in the +Y direction or the -Y direction, its bending is limited to within the allowable range.

[0048] [Operation] Next, the operation of the sewing machine 1 according to this embodiment will be described. FIG. 10 is a schematic diagram showing a comparative example in which the receiving member 33 is not provided. FIG. 11 is a schematic diagram showing this embodiment in which the receiving member 33 is provided. Bending of the sewing needle 4 typically occurs when the sewing object MS is thick or contains a hard material (such as leather or resin) due to external forces acting on the sewing needle 4 during sewing. Assume that the sewing needle 4 is bent in the +Y direction in which the lower feed mechanism 9 is located. Without the receiving member 33, as in the comparative example of FIG. 10 , deformation of the sewing needle 4 is not prevented, and the distance D between the sewing needle 4 and the point 13A increases. In this case, depending on the shape of the loop in the upper thread UT, the point 13A may not be able to capture the loop, potentially failing to entangle the upper thread UT with the bobbin thread. If the point 13A cannot capture the loop, a skipped stitch may occur at that needle point or the upper thread UT may break. A skipped stitch is when a stitch is not formed.

[0049] In the comparative example, in order to prevent skipped stitches and thread breakage, it is conceivable to adjust the positions of the shuttle 13 and the shuttle holder 14, for example. That is, by adjusting the position of the point 13A in consideration of the amount of bending deformation of the sewing machine needle 4, the distance D is adjusted to be appropriate. However, adjusting the positions of the shuttle 13 and the shuttle holder 14 requires partial disassembly of the connection points with the sewing machine power transmission mechanism, including the bed shaft 20 and the shuttle shaft, which is cumbersome and requires a large workload.

[0050] Furthermore, in the sewing machine 1, the sewing needle 4 is replaced with one of a different thickness (diameter) depending on the sewing object MS. The amount of bending deformation of the sewing needle 4 also changes depending on the thickness of the sewing needle 4 and the sewing object MS. In other words, when the thickness of the sewing needle 4 changes, the distance D between the sewing needle 4 and the point 13A also changes. Therefore, it may become necessary to adjust the positions of the shuttle 13 and the shuttle holder 14 every time the thickness of the sewing needle 4 is changed.

[0051] 11, in this embodiment, when the sewing needle 4 bends in the +Y direction, the receiving surface 34 of the receiving member 33 comes into contact with the bent sewing needle 4. The sewing needle 4 is prevented from further bending deformation by contact with the receiving surface 34. Since the distance D between the sewing needle 4 and the point 13A is prevented from increasing beyond the allowable range, the possibility that the point 13A will fail to capture the loop of the upper thread UT is reduced.

[0052] Furthermore, even when the sewing needle 4 is replaced with one of a different thickness (diameter), the distance CL between the receiving surface 34 and the needle path NP (sewing needle 4) can be easily adjusted simply by adjusting the feed rate of the adjusting member 36. In other words, rather than adjusting the passing position of the point 13A in accordance with the bending deformation of the sewing needle 4, the allowable range of bending deformation of the sewing needle 4 can be adjusted in accordance with the passing position of the point 13A. As a result, it is possible to prevent skipped stitches and thread breakage by simply adjusting the position of the receiving surface 34, without having to adjust the positions of the shuttle 13 and shuttle holder 14.

[0053] [Effects] As described above, the sewing machine 1 according to this embodiment includes the needle bar 6 that holds the sewing needle 4 and moves up and down to drop the needle on the sewing workpiece MS, the needle plate 7 that supports the sewing workpiece MS from below below the needle bar 6, the bottom feed mechanism 9 that feeds the sewing workpiece MS supported by the needle plate 7 from below, and the shuttle 13 that is disposed below the needle plate 7 and supplies a bobbin thread to the sewing workpiece MS. The bottom feed mechanism 9 includes the feed dog 31 that moves and feeds the sewing workpiece MS, the feed dog base 32 that holds the feed dog 31 and moves along a feed path, and the receiving member 33 that is provided on the feed dog base 32 and disposed to the side of the needle path NP of the sewing needle 4. The receiving member 33 faces the needle path NP and has a receiving surface 34 that can be adjusted in an adjustment direction (Y-axis direction) to move toward or away from the needle path NP.

[0054] According to this embodiment, even if the sewing needle 4 is bent, the amount of bending deformation of the sewing needle 4 can be limited by bringing the receiving surface 34 into contact with the bent sewing needle 4. Then, by adjusting the position of the receiving surface 34 relative to the needle penetration path NP, the allowable range of bending deformation of the sewing needle 4 can be adjusted to a range that can prevent skipped stitches and thread breakage. As a result, stable sewing can be achieved even under conditions where bending of the sewing needle 4 occurs.

[0055] In this embodiment, the receiving member 33 has a first portion 33A fixed to the feed dog table 32, a second portion 33B on which the receiving surface 34 is formed, and a third portion 33C connecting the first portion 33A and the second portion 33B. The receiving member 33 has a spring property that allows the second portion 33B to be displaced in the adjustment direction (Y-axis direction) by elastic deformation. The lower feed mechanism 9 includes an adjustment member 36 that displaces the second portion 33B in the adjustment direction (Y-axis direction). This allows the position of the receiving surface 34 to be adjusted with a simple structure by utilizing the elastic deformation of the second portion 33B of the receiving member 33. Furthermore, even when the receiving surface 34 is displaced in the +Y direction away from the needle drop path NP, the elasticity (restoring force) of the second portion 33B can be utilized to prevent the receiving surface 34 from shifting out of position.

[0056] In this embodiment, the adjustment member 36 is a feed screw that is attached to the feed dog table 32 so as to abut against the second portion 33B and is provided so as to be movable back and forth in the adjustment direction (Y-axis direction). This allows the position of the receiving surface 34 to be adjusted by the extremely simple task of simply adjusting the feed amount of the feed screw. Therefore, even if the position of the receiving surface 34 is adjusted every time the thickness of the sewing machine needle 4 is changed, the burden and complexity of the adjustment task can be reduced.

[0057] In this embodiment, the position of the receiving surface 34 can be adjusted between a position closer to the needle path NP than the side surface 31F of the wall portion 31B on the needle path NP side, and a position farther from the needle path NP than the side surface 31F. This allows the position adjustment range of the receiving surface 34 to be sufficiently large.

[0058] In this embodiment, the receiving surface 34 of the receiving member 33 faces the needle receiving portion 13B of the shuttle 13 in the adjustment direction (Y-axis direction). This makes it possible to limit the amount of bending deformation of the sewing needle 4 within an allowable range both when the sewing needle 4 bends toward the feed dog 31 (+Y direction) and when the sewing needle 4 bends toward the shuttle 13 (-Y direction).

[0059] In this embodiment, the sewing machine 1 is an integrated feed sewing machine in which the feed dog 31 of the lower feed mechanism 9, the upper feed mechanism 12, and the needle bar 6 are operated on feed trajectories that are linked to one another. This improves the feed force and enables sewing of thicker sewing objects MS. Bending of the sewing needle 4 is particularly likely to occur when sewing thicker sewing objects MS. Therefore, the integrated feed sewing machine can achieve stable sewing even when sewing thick materials, which are prone to bending of the sewing needle 4.

[0060] [Other Embodiments] In the above-described embodiment, the sewing machine 1 is an integrated feed sewing machine, but the feeding method of the sewing machine is not particularly limited. The feeding method of the sewing machine may be bottom feed only, feed and needle feed, or up-down feed (up-down feed and down-down feed), etc. Therefore, the sewing machine 1 does not need to be provided with the top feed 12, and the needle bar 6 does not need to move along a needle feed path. The needle bar 6 may move only up and down.

[0061] In the above embodiment, the hook 13 is a horizontal hook, but the hook may be a vertical hook whose central axis of rotation is oriented horizontally.

[0062] In the above-described embodiment, an example was shown in which the position of the receiving surface 34 was adjusted by elastically deforming the receiving member 33. However, the structure for adjusting the position of the receiving surface 34 is not particularly limited. For example, a receiving member having a receiving surface may be attached to the tip of the feed screw, and the receiving member may be moved horizontally in the adjustment direction according to the amount of feed screw operation. Furthermore, the adjustment member is not limited to a feed screw, and may be, for example, an eccentric cam that adjusts the position of the receiving member. The receiving member may be provided with a plurality of insertion holes along the adjustment direction, and positioning pins inserted into the insertion holes may serve as the adjustment members. The receiving member may be provided with elongated holes along the adjustment direction, and screws may be provided as the adjustment members that are inserted into the elongated holes and fasten the receiving member so that the position can be adjusted within the range of the elongated holes.

[0063] The present disclosure includes the following aspects: (1) A sewing machine comprising: a needle bar that holds a sewing machine needle and moves up and down to drop the needle on a sewing object, a needle plate that supports the sewing object from below below the needle bar, a bottom feed mechanism that feeds the sewing object supported by the needle plate from below, and a shuttle that is arranged below the needle plate and supplies a bobbin thread to the sewing object, wherein the bottom feed mechanism includes: a feed dog that feeds the sewing object, a feed dog base that holds the feed dog and moves along a feed orbit, and a receiving member that is provided on the feed dog base and arranged to the side of a needle drop path of the sewing machine needle, and the receiving member has a receiving surface that faces the needle drop path and is positionable in an adjustment direction to move closer to or away from the needle drop path. (2) The sewing machine according to (1), wherein the receiving member has a first portion fixed to the feed dog base, a second portion on which the receiving surface is formed, and a third portion connecting the first portion and the second portion, and has spring properties that allow the second portion to be displaced in the adjustment direction by elastic deformation, and the lower feed mechanism includes an adjustment member that displaces the second portion in the adjustment direction. (3) The sewing machine according to (2), wherein the adjustment member is a feed screw that is attached to the feed dog base so as to abut against the second portion and is provided so as to be able to move forward and backward in the adjustment direction. (4) The sewing machine according to any one of (1) to (3), wherein the feed dog has a fixed portion fixed to the feed dog base, a wall portion extending upward from the fixed portion, and an upper surface portion provided at an upper end of the wall portion and that comes into contact with the sewing object, and the receiving surface is positionably adjustable between a position closer to the needle path than a side surface of the wall portion on the needle path side, and a position farther from the needle path than the side surface. (5) The sewing machine according to any one of (1) to (4), wherein the shuttle has a needle receiving portion, and the receiving surface of the receiving member faces the needle receiving portion of the shuttle in the adjustment direction. (6) The sewing machine according to any one of (1) to (5), further comprising an upper feed that feeds the sewing object supported by the needle plate from above, and wherein the feed dog of the lower feed mechanism, the upper feed, and the needle bar are operated on feed tracks that are linked to each other.

[0064] This application is based on Japanese Patent Application No. 2023-148190 filed on September 13, 2023, the contents of which are incorporated herein by reference.

Claims

1. A sewing machine comprising: a needle bar which holds a sewing needle and moves up and down to drop the needle on an object to be sewn; a needle plate which supports the object to be sewn from below below the needle bar; a bottom feed mechanism which feeds the object to be sewn supported by the needle plate from below; and a hook which is arranged below the needle plate and supplies a bobbin thread to the object to be sewn, wherein the bottom feed mechanism includes: a feed dog which feeds and moves the object to be sewn; a feed dog stand which holds the feed dog and moves according to a feed orbit; and a receiving member which is provided on the feed dog stand and is arranged to the side of the needle drop path of the sewing needle, and the receiving member has a receiving surface which faces the needle drop path and can be adjusted in a direction to approach or move away from the needle drop path.

2. The sewing machine described in claim 1, wherein the receiving member has a first portion fixed to the feed dog table, a second portion on which the receiving surface is formed, and a third portion connecting the first portion and the second portion, and has a spring property that enables the second portion to be displaced in the adjustment direction by elastic deformation, and the lower feed mechanism includes an adjustment member that displaces the second portion in the adjustment direction.

3. The sewing machine according to claim 2, wherein the adjustment member is a feed screw that is attached to the feed dog table so as to abut against the second portion and is provided so as to be movable forward and backward in the adjustment direction.

4. A sewing machine as claimed in any one of claims 1 to 3, wherein the feed dog has a fixed portion fixed to the feed dog table, a wall portion extending upward from the fixed portion, and an upper surface portion provided at the upper end of the wall portion and contacting the workpiece to be sewn, and the receiving surface is positionable between a position closer to the needle drop path than the side surface of the wall portion on the needle drop path side, and a position farther from the needle drop path than the side surface.

5. A sewing machine as claimed in any one of claims 1 to 3, wherein the shuttle has a needle receiving portion, and the receiving surface of the receiving member faces the needle receiving portion of the shuttle in the adjustment direction.

6. A sewing machine as claimed in any one of claims 1 to 3, further comprising an upper feed mechanism for feeding the sewing object supported by the needle plate from above, and which is an integrated feed sewing machine in which the feed dog of the lower feed mechanism, the upper feed mechanism and the needle bar are operated on a feed trajectory that is linked to one another.

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