Sewing machine

Abstract

And adjusting the stitch shape. The sewing machine includes: a frame including a bed portion having an upper surface; a cylinder portion protruding from the bed portion toward one side in a first direction of a predetermined surface parallel to the upper surface, the cylinder portion having a size smaller than that of the bed portion in a second direction orthogonal to the first direction on the predetermined surface; a body section extending upward from the bed section in a third direction orthogonal to the predetermined surface; the arm part extends from the upper end of the machine body part to one side of the first direction; a head portion protruding downward from the arm portion; a needle rod movably supported on the head, holding a sewing machine needle, and reciprocating in a third direction, the sewing machine needle holding an upper thread; a pressing member that presses a sewing object disposed at a sewing position directly below the sewing machine needle; an annular first lower feeding belt which is arranged on one side of the sewing position in the first direction and moves and feeds the sewing object in the second direction; and an annular second lower feeding belt which is arranged on the other side of the sewing position and moves and feeds the sewing object in the second direction independently from the first lower feeding belt. The first lower feeding belt and the second lower feeding belt are arranged in the cylinder part.

Description

TECHNICAL FIELD

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

[0002] In the technical field of sewing machines, a cylinder-type sewing machine disclosed in Patent Literature 1 is known.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2014-057758 SUMMARY

[0006] (1) Problem to be Solved by the Invention

[0007] A sewing machine forms a stitch while feeding a sewing object in a prescribed feed direction to manufacture a sewn product. For example, in order to improve the designability of the sewn product, a technique capable of arbitrarily adjusting the stitch shape is desired.

[0008] The technology disclosed in this specification aims to adjust the stitch shape.

[0009] (2) Solution to Problem

[0010] The present specification discloses a sewing machine. The sewing machine includes a frame having a bed portion having an upper surface, a cylinder portion protruding from the bed portion to one side in a first direction of a prescribed surface parallel to the upper surface, a dimension in a second direction orthogonal to the first direction on the prescribed surface being smaller than the bed portion, a body portion extending from an upper end portion of the bed portion to an upper side in a third direction orthogonal to the prescribed surface, an arm portion extending from an upper end portion of the body portion to one side in the first direction, and a head portion protruding from the arm portion to a lower side, a needle bar supported to the head portion in a movable manner, reciprocating in the third direction in a state of holding a sewing machine needle that holds an upper thread, a presser member that presses a sewing object disposed at a sewing position directly below the sewing machine needle, a first lower feed belt that is annular, disposed at one side of the sewing position in the first direction, and moves in a manner of feeding the sewing object in the second direction, and a second lower feed belt that is annular, disposed at the other side of the sewing position in the first direction, and moves in a manner of feeding the sewing object in the second direction independently of the first lower feed belt. The first lower feed belt and the second lower feed belt are disposed in an inner space of the cylinder portion.

[0011] (3) Effects of the Invention

[0012] According to the present disclosure, the stitch shape can be adjusted. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a perspective view from the left upper rear side showing the sewing machine of the first embodiment.

[0014] Figure 2 is a left side view obtained by partially cutting the sewing machine of the first embodiment.

[0015] Figure 3 is a perspective view from the left upper rear side showing the inside space of the bobbin case of the first embodiment.

[0016] Figure 4 is a perspective view from the left upper rear side showing a part of the lower feed mechanism of the first embodiment.

[0017] Figure 5 is a plan view showing the lower feed mechanism of the first embodiment.

[0018] Figure 6 is a left side view showing the lower feed mechanism of the first embodiment.

[0019] Figure 7 is a perspective view from the left upper rear side showing the lower feed mechanism of the first embodiment.

[0020] Figure 8 is a block diagram showing the controller of the sewing machine of the embodiment.

[0021] Figure 9 is a diagram for explaining a stitch formed in the sewing object of the embodiment.

[0022] Figure 10 is a plan view showing the lower feed mechanism of the second embodiment.

[0023] Figure 11 is a perspective view from the left upper rear side showing the lower feed mechanism of the second embodiment.

[0024] Figure 12 is a plan view showing the lower feed mechanism of the third embodiment.

[0025] Figure 13 is a left side view showing the lower feed mechanism of the third embodiment.

[0026] Figure 14 is a perspective view from the left upper rear side showing the lower feed mechanism of the third embodiment.

[0027] Figure 15 is a rear view showing a part of the lower feed mechanism of the embodiment.

[0028] Figure 16 is a sectional view showing a part of the lower feed mechanism of the embodiment.

[0029] Figure 17 is a bottom view of the lower feed mechanism.

[0030] Figure 18 is a bottom view of the lower feed mechanism.

[0031] Figure 19 is a bottom view of the lower feed mechanism.

[0032] Figure 20 is a bottom view of the lower feed mechanism.

[0033] BRIEF DESCRIPTION OF REFERENCE NUMERALS

[0034] 1…sewing machine, 2…frame, 3…sewing needle, 4…needle bar, 5…thread take-up lever, 6…thread clamp, 7…needle plate, 8…presser, 9…bobbin case, 10…upper feed mechanism, 11A…lower feed mechanism, 11B…lower feed mechanism, 11C…lower feed mechanism, 12…sewing machine motor, 13…first upper feed belt, 14…second upper feed belt, 15…first upper feed motor, 15A…first upper feed sprocket, 16…second upper feed motor, 16A…second upper feed sprocket, 17…belt support mechanism, 17A…pulley, 17B…support, 18…motor support mechanism, 18A…support, 18B…fixing mechanism, 19…bobbin case shaft, 20…bed portion, 20A…upper surface, 21…cylinder portion, 21A…upper surface, 21C…cylinder portion, 21X…first portion, 21Y…second portion, 22…machine body portion, 23…arm portion, 24…head portion, 30…guide member, 31…first lower feed belt, 31A…first lower feed belt, 31B…first lower feed belt, 32…second lower feed belt, 32A…second lower feed belt, 32B…second lower feed belt, 33…first lower feed sprocket, 34…second lower feed sprocket, 35…first lower feed motor, 35A…stator, 35B…rotor shaft, 36…second lower feed motor, 36A…stator, 36B…rotor shaft, 37…first lower feed shaft, 37A…first input shaft, 37B…first output shaft, 37C…first transmission mechanism, 37D…first input sprocket, 37E…first output sprocket, 38…second lower feed shaft, 38A…second input shaft, 38B…second output shaft, 38C…second transmission mechanism, 38D…second input sprocket, 38E…second output sprocket, 39…first coupling, 40…second coupling, 41…first bearing, 42…second bearing, 50…controller, 51…processor, 52…main memory, 53…storage device, 54…input / output interface, 55…operation panel, 70…needle hole, 71…opening, 71A…opening, 71B…opening, 72…opening, 72A…opening, 72B…opening, 210…main body portion, 210A…front plate portion, 210B…rear plate portion, 210C…upper plate portion, 210D…lower plate portion, 211…cover portion, 211A…left plate portion, 211B…upper plate portion, 381…second input shaft, 382…output sprocket, 383…input sprocket, 384…transmission mechanism, CX1…rotation axis, CX2…rotation axis, DX1…rotation axis, DX2…rotation axis, PS…stitch position, SE…stitch. DETAILED DESCRIPTION

[0035] Hereinafter, the embodiments will be described with reference to the drawings. The constituent elements of each of the embodiments described below can be appropriately combined. In addition, there are cases where a part of the constituent elements is not used.

[0036] In the embodiment, the positional relationship of each part is described using the terms "left", "right", "front", "back", "upper", and "lower". These terms indicate relative positions or directions with the center of the sewing machine 1 as a reference. The left-right direction is a first direction parallel to the left-right axis of the local coordinate system defined by the sewing machine 1. The front-back direction is a second direction parallel to the front-back axis of the local coordinate system defined by the sewing machine 1. The up-down direction is a third direction parallel to the up-down axis of the local coordinate system defined by the sewing machine 1. The left-right axis (first direction), the front-back axis (second direction), and the up-down axis (third direction) are orthogonal to each other. One side of the first direction is the left side, and the other side of the first direction is the right side. One side of the second direction is the front side, and the other side of the second direction is the back side. One side of the third direction is the upper side, and the other side of the third direction is the lower side. The third direction is orthogonal to the defined plane including the left-right axis (first direction) and the front-back axis (second direction). In the embodiment, the defined plane is parallel to the horizontal plane. In addition, the defined plane can be inclined with respect to the horizontal plane.

[0037] [First Embodiment]

[0038] The first embodiment will be described.

[0039] [Outline of Sewing Machine]

[0040] Figure 1 is a perspective view of a sewing machine 1 according to the embodiment, as viewed from the left upper back side. Figure 2 is a left side view of the sewing machine 1 according to the embodiment, obtained by partially cutting the sewing machine 1. In the embodiment, the sewing machine 1 is a cylinder type sewing machine.

[0041] As shown in Figure 1 and Figure 2 , the sewing machine 1 includes a frame 2, a needle bar 4, a thread take-up lever 5, a thread clamp 6, a needle plate 7, a presser member 8, a bobbin 9, a sewing machine motor 12, an upper feed mechanism 10, and a lower feed mechanism 11A.

[0042] The frame 2 is a structure that supports the needle bar 4, the thread take-up lever 5, the thread clamp 6, the needle plate 7, the presser member, the bobbin 9, the upper feed mechanism 10, and the lower feed mechanism 11A, respectively. The frame 2 has a bed portion 20, a cylinder portion 21, a body portion 22, an arm portion 23, and a head portion 24.

[0043] The bed portion 20 is disposed at the lower portion of the frame 2. The bed portion 20 has an upper surface 20A. The upper surface 20A is parallel to a defined plane including the left-right direction (first direction) and the front-back direction (second direction). The bed portion 20 has an internal space.

[0044] The tubular portion 21 protrudes to the left side from the left end portion of the bed portion 20. The tubular portion 21 has an upper surface 21A. In the left-right direction, the size of the tubular portion 21 is smaller than the size of the bed portion 20. In the front-rear direction, the size of the tubular portion 21 is smaller than the size of the bed portion 20. In the up-down direction, the size of the tubular portion 21 is smaller than the size of the bed portion 20.

[0045] The upper surface 20A of the bed portion 20 and the upper surface 21A of the tubular portion 21 are arranged in the same plane. That is, the upper surface 20A of the bed portion 20 is coplanar with the upper surface 21A of the tubular portion 21. In the up-down direction, the upper surface 20A of the bed portion 20 and the upper surface 21A of the tubular portion 21 are arranged at the same position. The lower surface of the tubular portion 21 is arranged at a position more upward than the lower surface of the bed portion 20. The front surface of the tubular portion 21 is arranged at a position more rearward than the front surface of the bed portion 20. The rear surface of the tubular portion 21 is arranged at a position more forward than the rear surface of the bed portion 20.

[0046] The outer shape of the tubular portion 21 is substantially rectangular parallelepiped. The size of the tubular portion 21 in the left-right direction is larger than the size of the tubular portion 21 in the front-rear direction and the up-down direction. The size of the tubular portion 21 in the front-rear direction is larger than the size of the tubular portion 21 in the up-down direction. The size of the tubular portion 21 in the front-rear direction can also be smaller than the size of the tubular portion 21 in the up-down direction. The size of the tubular portion 21 in the front-rear direction can also be the same as the size of the tubular portion 21 in the up-down direction.

[0047] The tubular portion 21 has an internal space. The tubular portion 21 has a main body portion 210 and a cover portion 211. The cover portion 211 is arranged to close an opening of the main body portion 210. The cover portion 211 is detachable with respect to the main body portion 210.

[0048] The main body portion 210 has a front plate portion 210A, a rear plate portion 210B, an upper plate portion 210C, and a lower plate portion 210D. The front plate portion 210A is arranged at a position more forward than the rear plate portion 210B. The front plate portion 210A and the rear plate portion 210B are opposed with a gap therebetween. A front end portion of the upper plate portion 210C is connected to an upper end portion of the front plate portion 210A. A rear end portion of the upper plate portion 210C is connected to an upper end portion of the rear plate portion 210B. The lower plate portion 210D is arranged on the lower side of the upper plate portion 210C. The upper plate portion 210C and the lower plate portion 210D are opposed with a gap therebetween. A front end portion of the lower plate portion 210D is connected to a lower end portion of the front plate portion 210A. A rear end portion of the lower plate portion 210D is connected to a lower end portion of the rear plate portion 210B. A left end portion of the lower plate portion 210D is arranged at a position more leftward than a left end portion of the upper plate portion 210C. An opening is provided at the left end portion of the main body portion 210. An opening is provided at the left portion of the upper end portion of the main body portion 210.

[0049] The cover portion 211 is configured to close the opening of the main body portion 210. The cover portion 211 has a left plate portion 211A that closes the opening of the left end portion of the main body portion 210 and an upper plate portion 211B that closes the opening of the left portion of the upper end portion of the main body portion 210. The upper end portion of the left plate portion 211A is connected to the left end portion of the upper plate portion 211B.

[0050] The upper surface 21A of the cylinder portion 21 includes the upper surface of the upper plate portion 210C of the main body portion 210 and the upper surface of the upper plate portion 211B of the cover portion 211. The upper surface of the upper plate portion 210C and the upper surface of the upper plate portion 211B of the cover portion 211 are configured in the same plane. That is, the upper surface of the upper plate portion 210C is coplanar with the upper surface of the upper plate portion 211B of the cover portion 211.

[0051] The body portion 22 extends upward from the right end portion of the bed portion 20. The arm portion 23 extends leftward from the upper end portion of the body portion 22. The head portion 24 protrudes downward from the left end portion of the arm portion 23. The body portion 22 connects the right end portion of the bed portion 20 and the right end portion of the arm portion 23. The bed portion 20 and the cylinder portion 21 are disposed below the arm portion 23 and the head portion 24. The arm portion 23 opposes at least a portion of the bed portion 20. The head portion 24 opposes at least a portion of the cylinder portion 21.

[0052] The needle bar 4 is supported to the head portion 24 so as to be movable in the up-down direction. The needle bar 4 reciprocates in the up-down direction while holding the sewing machine needle 3. The needle bar 4 holds the sewing machine needle 3 so that the sewing machine needle 3 is parallel to the up-down axis. The needle bar 4 is disposed above the needle plate 7 so as to be able to oppose the surface of the object to be sewn. The upper thread is hung on the sewing machine needle 3. The sewing machine needle 3 has a threading hole through which the upper thread passes. The sewing machine needle 3 holds the upper thread on the inner surface of the threading hole. The sewing machine needle 3 reciprocates in the up-down direction while holding the upper thread, by the needle bar 4 reciprocating in the up-down direction.

[0053] The thread take-up lever 5 feeds the upper thread to the sewing machine needle 3. The thread take-up lever 5 is supported to the head portion 24. The thread take-up lever 5 has a thread take-up lever hole through which the upper thread passes. The thread take-up lever 5 holds the upper thread on the inner surface of the thread take-up lever hole. The thread take-up lever 5 reciprocates in the up-down direction while holding the upper thread. The thread take-up lever 5 reciprocates in conjunction with the needle bar 4. The thread take-up lever 5 feeds or pulls the upper thread by reciprocating in the up-down direction.

[0054] The thread tensioner 6 applies tension to the upper thread. The thread tensioner 6 adjusts the tension of the upper thread. The upper thread is fed to the thread tensioner 6 from a thread supply source. The thread take-up lever 5 is disposed between the sewing machine needle 3 and the thread tensioner 6 in a path through which the upper thread passes. The thread tensioner 6 adjusts the tension of the upper thread fed to the sewing machine needle 3 via the thread take-up lever 5.

[0055] The needle plate 7 supports a sewing object. The needle plate 7 is supported to the tubular portion 21. In the left-right direction, the needle plate 7 is disposed between the upper plate portion 210C of the main body portion 210 and the upper plate portion 211B of the cover portion 211. The sewing machine needle 3 held to the needle bar 4 opposes the needle plate 7. The needle plate 7 has a needle hole 70 through which the sewing machine needle 3 can pass. The sewing machine needle 3 that penetrates the sewing object supported to the needle plate 7 passes through the needle hole 70 of the needle plate 7.

[0056] The presser member 8 presses the sewing object disposed at the sewing position PS directly below the sewing machine needle 3. The sewing position PS includes a so-called drop position at which the sewing machine needle 3 penetrates the sewing object. The sewing position PS includes the needle hole 70 of the needle plate 7. The presser member 8 is disposed on the upper side of the needle plate 7. The presser member 8 opposes the needle plate 7. The presser member 8 presses the sewing object from the upper side. The presser member 8 holds the sewing object between the presser member 8 and the needle plate 7.

[0057] The bobbin 9 holds a bobbin (not shown) housed in a bobbin case. The bobbin case is housed in the bobbin 9. The bobbin 9 is disposed in the inside space of the tubular portion 21. The bobbin 9 is disposed on the lower side of the needle plate 7. The bobbin 9 rotates in conjunction with the needle bar 4. The bobbin 9 feeds the upper thread to the lower thread. The bobbin 9 hooks (Japanese: sukuinagiru) the upper thread from the sewing machine needle 3 that penetrates the sewing object supported to the needle plate 7 through the needle hole of the needle plate 7.

[0058] The sewing machine motor 12 generates power. The sewing machine motor 12 is disposed at the right end portion of the arm portion 23. The power generated by the sewing machine motor 12 is transmitted to the needle bar 4, the thread take-up lever 5, and the bobbin 9, respectively, via a power transmission mechanism (not shown). The needle bar 4, the thread take-up lever 5, and the bobbin 9 are linked. The power generated by the sewing machine motor 12 is transmitted to the needle bar 4, whereby the needle bar 4 and the sewing machine needle 3 held to the needle bar 4 move reciprocally in the up-down direction. The power generated by the sewing machine motor 12 is transmitted to the thread take-up lever 5, whereby the thread take-up lever 5 moves reciprocally in the up-down direction in conjunction with the needle bar 4. The power generated by the sewing machine motor 12 is transmitted to the bobbin 9, whereby the bobbin 9 rotates in conjunction with the needle bar 4 and the thread take-up lever 5. The sewing machine 1 sews the sewing object by the cooperative action of the sewing machine needle 3 held to the needle bar 4 and the bobbin 9.

[0059] <Upper Feed Mechanism>

[0060] The upper feed mechanism 10 feeds the sewing object in the front-rear direction. The upper feed mechanism 10 is disposed at a position more on the upper side than the tubular portion 21. At least a portion of the upper feed mechanism 10 opposes the upper surface 21A of the tubular portion 21. At least a portion of the upper feed mechanism 10 opposes the upper surface of the needle plate 7. The upper feed mechanism 10 includes the presser member 8.

[0061] The upper feed mechanism 10 has a first upper feed belt 13, a second upper feed belt 14, a first upper feed motor 15, a second upper feed motor 16, a belt support mechanism 17, and a motor support mechanism 18.

[0062] The first upper feed belt 13 and the second upper feed belt 14 are each annular. The first upper feed belt 13 and the second upper feed belt 14 are each a so-called endless belt. The first upper feed belt 13 and the second upper feed belt 14 are arranged in the left-right direction. The first upper feed belt 13 is arranged on the left side of the sewing machine needle 3. The second upper feed belt 14 is arranged on the right side of the sewing machine needle 3. The lower end portion of the first upper feed belt 13 is arranged on the left side of the sewing position PS directly below the sewing machine needle 3. The lower end portion of the second upper feed belt 14 is arranged on the right side of the sewing position PS directly below the sewing machine needle 3. The lower end portions of the first upper feed belt 13 and the second upper feed belt 14 each contact the upper surface of the sewing object. The first upper feed belt 13 and the second upper feed belt 14 each move in a manner to feed the sewing object in the forward direction. In a state in which the lower end portion of the first upper feed belt 13 contacts the upper surface of the sewing object, the first upper feed belt 13 rotates, whereby the first upper feed belt 13 can feed the sewing object. In a state in which the lower end portion of the second upper feed belt 14 contacts the upper surface of the sewing object, the second upper feed belt 14 rotates, whereby the second upper feed belt 14 can feed the sewing object.

[0063] The second upper feed belt 14 can independently of the first upper feed belt 13 move in a manner to feed the sewing object in the forward direction. The second upper feed belt 14 can feed the sewing object at a different feed amount (feed speed) than the feed amount (feed speed) of the sewing object based on the first upper feed belt 13.

[0064] The first upper feed motor 15 generates a rotational force for moving the first upper feed belt 13. The second upper feed motor 16 generates a rotational force for moving the second upper feed belt 14. The first upper feed sprocket 15A is connected to the first upper feed motor 15. The second upper feed sprocket 16A is connected to the second upper feed motor 16. The upper end portion of the first upper feed belt 13 is hung on the first upper feed sprocket 15A. The upper end portion of the second upper feed belt 14 is hung on the second upper feed sprocket 16A.

[0065] The belt support mechanism 17 supports the first upper feed belt 13 and the second upper feed belt 14. The belt support mechanism 17 includes a plurality of pulleys 17A movably supporting the first upper feed belt 13 and the second upper feed belt 14, and a bracket 17B supporting the pulleys 17A. The pressing member 8 is supported at the lower end portion of the bracket 17B.

[0066] The motor support mechanism 18 supports the first upper feed motor 15 and the second upper feed motor 16, respectively. The motor support mechanism 18 supports the first upper feed sprocket 15A and the second upper feed sprocket 16A, respectively. The motor support mechanism 18 includes a bracket 18A that supports the first upper feed motor 15, the second upper feed motor 16, the first upper feed sprocket 15A, and the second upper feed sprocket 16A, respectively, and a fixing mechanism 18B that fixes the bracket 18A to the rear surface of the head 24. The upper portion of the bracket 17B of the belt support mechanism 17 is fixed to the lower portion of the bracket 18A of the motor support mechanism 18. The first upper feed belt 13 and the second upper feed belt 14 are supported to the head 24 via the belt support mechanism 17 and the motor support mechanism 18.

[0067] The first upper feed motor 15 is driven to rotate the first upper feed sprocket 15A in one direction, whereby the first upper feed belt 13 is rotated in one direction. The first upper feed belt 13 is rotated in one direction, and the lower surface of the lower end portion of the first upper feed belt 13 that contacts the upper surface of the sewing object is moved to the front side, whereby the sewing object is fed to the front side by the first upper feed belt 13.

[0068] The second upper feed motor 16 is driven to rotate the second upper feed sprocket 16A in one direction, whereby the second upper feed belt 14 is rotated in one direction. The second upper feed belt 14 is rotated in one direction, and the lower surface of the lower end portion of the second upper feed belt 14 that contacts the upper surface of the sewing object is moved to the front side, whereby the sewing object is fed to the front side by the second upper feed belt 14.

[0069] A difference is provided between the feed amount (feed speed) of the sewing object based on the first upper feed belt 13 and the feed amount (feed speed) of the sewing object based on the second upper feed belt 14 by providing a difference between the rotational speed of the first upper feed motor 15 (the first upper feed sprocket 15A) and the rotational speed of the second upper feed motor 16 (the second upper feed sprocket 16A). The second upper feed belt 14 can feed the sewing object at a different feed amount (feed speed) from the feed amount (feed speed) of the sewing object based on the first upper feed belt 13.

[0070] In addition, the first upper feed belt 13 and the second upper feed belt 14 can also be moved in a manner that feeds the sewing object to the rear side, respectively.

[0071] <Lower Feed Mechanism>

[0072] Figure 3 FIG. 17 is a perspective view from the upper left rear side that shows the inside space of the cylinder portion 21 of the embodiment. Figure 4 FIG. 18 is a perspective view from the upper left rear side that shows a part of the lower feed mechanism 11A of the embodiment. Figure 5is a bottom view of the lower feed mechanism 11A of the embodiment. Figure 6 is a left side view of the lower feed mechanism 11A of the embodiment, corresponding to Figure 5 is an A-A line cross-sectional view of Figure 7 is a perspective view of the lower feed mechanism 11A of the embodiment, viewed from the left upper rear side.

[0073] The lower feed mechanism 11A feeds the sewing object in the front-rear direction. At least a part of the lower feed mechanism 11A is disposed in the internal space of the cylinder portion 21. At least a part of the lower feed mechanism 11A is disposed directly below the needle plate 7. At least a part of the lower feed mechanism 11A opposes the lower surface of the needle plate 7. At least a part of the lower feed mechanism 11A is disposed in the internal space of the bed portion 20.

[0074] The lower feed mechanism 11A has a first lower feed belt 31, a second lower feed belt 32, a first lower feed sprocket 33, a second lower feed sprocket 34, a first lower feed motor 35, a second lower feed motor 36, a first lower feed shaft 37, and a second lower feed shaft 38.

[0075] The first lower feed belt 31 and the second lower feed belt 32 are each annular. The first lower feed belt 31 and the second lower feed belt 32 are each a so-called endless belt. The first lower feed belt 31 and the second lower feed belt 32 are disposed in the left-right direction. The first lower feed belt 31 is disposed on the left side of the sewing machine needle 3. The second lower feed belt 32 is disposed on the right side of the sewing machine needle 3. The upper end portion of the first lower feed belt 31 is disposed at a position further to the left than the sewing position PS directly below the sewing machine needle 3. The upper end portion of the second lower feed belt 32 is disposed at a position further to the right than the sewing position PS directly below the sewing machine needle 3. The sewing position PS includes the needle hole 70 of the needle plate 7 through which the sewing machine needle 3 passes.

[0076] The upper end portion of the first lower feed belt 31 is disposed in the opening 71 provided in the needle plate 7. The upper end portion of the second lower feed belt 32 is disposed in the opening 72 provided in the needle plate 7. The opening 71 is provided at a position further to the left than the needle hole 70. The opening 72 is provided at a position further to the right than the needle hole 70. The upper end portion of the first lower feed belt 31 contacts the lower surface of the sewing object via the opening 71 of the needle plate 7. The upper end portion of the second lower feed belt 32 contacts the lower surface of the sewing object via the opening 72 of the needle plate 7.

[0077] The first lower feed belt 31 and the second lower feed belt 32 are each movable in a manner to feed the sewing object to the front side. The first lower feed belt 31 is rotatable in a state in which the upper end portion of the first lower feed belt 31 is in contact with the lower surface of the sewing object, and thus the first lower feed belt 31 can feed the sewing object. The second lower feed belt 32 is rotatable in a state in which the upper end portion of the second lower feed belt 32 is in contact with the lower surface of the sewing object, and thus the second lower feed belt 32 can feed the sewing object.

[0078] The second lower feed belt 32 is independently movable from the first lower feed belt 31 in a manner to feed the sewing object to the front side. The second lower feed belt 32 can feed the sewing object at a different feed amount (feed speed) than the feed amount (feed speed) of the sewing object based on the first lower feed belt 31.

[0079] The first lower feed belt 31 is provided in two. The first lower feed belt 31 includes a first lower feed belt 31A and a first lower feed belt 31B disposed at a position more to the left side than the first lower feed belt 31A. The first lower feed belt 31A and the first lower feed belt 31B are each disposed at a position more to the left side than the sewing position PS directly below the sewing machine needle 3. The opening 71 of the needle plate 7 includes an opening 71A in which the upper end portion of the first lower feed belt 31A is disposed and an opening 71B in which the upper end portion of the first lower feed belt 31B is disposed.

[0080] The second lower feed belt 32 is provided in two. The second lower feed belt 32 includes a second lower feed belt 32A and a second lower feed belt 32B disposed at a position more to the right side than the second lower feed belt 32A. The second lower feed belt 32A and the second lower feed belt 32B are each disposed at a position more to the right side than the sewing position PS directly below the sewing machine needle 3. The opening 72 of the needle plate 7 includes an opening 72A in which the upper end portion of the second lower feed belt 32A is disposed and an opening 72B in which the upper end portion of the second lower feed belt 32B is disposed.

[0081] The first lower feed belt 31 and the second lower feed belt 32 are disposed in the internal space of the cylinder portion 21. At least a portion of the first lower feed belt 31 is disposed directly below the needle plate 7. At least a portion of the second lower feed belt 32 is disposed directly below the needle plate 7.

[0082] The lower portion of the first lower feed belt 31 is hung on the first lower feed sprocket 33. The lower portion of the second lower feed belt 32 is hung on the second lower feed sprocket 34. The first lower feed sprocket 33 is rotatable in a state in which the first lower feed belt 31 is supported, and thus the first lower feed belt 31 is moved. The second lower feed sprocket 34 is rotatable in a state in which the second lower feed belt 32 is supported, and thus the second lower feed belt 32 is moved. The first lower feed sprocket 33 and the second lower feed sprocket 34 are disposed in the internal space of the cylinder portion 21.

[0083] The first lower feed sprocket 33 and the second lower feed sprocket 34 are arranged in the interior space of the cylinder portion 21 in the front-rear direction. The first lower feed sprocket 33 is arranged at a position more on the front side than the second lower feed sprocket 34. In the left-right direction, the position of the first lower feed sprocket 33 is the same as the position of at least a part of the second lower feed sprocket 34. In the up-down direction, the position of the first lower feed sprocket 33 is the same as the position of at least a part of the second lower feed sprocket 34.

[0084] The cauldron 9 is arranged in the interior space of the cylinder portion 21. The power generated by the sewing machine motor 12 is transmitted to the cauldron 9 via the cauldron shaft 19. The power generated by the sewing machine motor 12 is transmitted to the cauldron 9, whereby the cauldron 9 rotates in conjunction with the needle bar 4 and the thread take-up lever 5. A guide member 30 is arranged around the cauldron 9. The guide member 30 is circular ring-shaped. The guide member 30 supports the first lower feed belt 31 and the second lower feed belt 32 respectively. The first lower feed belt 31 is arranged around the guide member 30. The second lower feed belt 32 is arranged around the guide member 30. When the first lower feed sprocket 33 rotates, the first lower feed belt 31 rotates while being guided by the guide member 30. When the second lower feed sprocket 34 rotates, the second lower feed belt 32 rotates while being guided by the guide member 30. The cauldron 9 and the guide member 30 are arranged inside the first lower feed belt 31 and the second lower feed belt 32 which are ring-shaped.

[0085] By detaching the cover portion 211 from the main body portion 210, the user of the sewing machine 1 can replace the bobbin of the cauldron 9, or rethread the first lower feed belt 31, or rethread the second lower feed belt 32.

[0086] The first lower feed motor 35 generates a rotational force for moving the first lower feed belt 31. The second lower feed motor 36 generates a rotational force for moving the second lower feed belt 32. In the embodiment, the first lower feed motor 35 generates a rotational force for rotating the first lower feed sprocket 33. The second lower feed motor 36 generates a rotational force for rotating the second lower feed sprocket 34. The first lower feed motor 35 and the second lower feed motor 36 are arranged in the interior space of the bed portion 20.

[0087] The first lower feed motor 35 has a stator 35A supported to the bed portion 20 and a rotor shaft 35B which rotates inside the stator 35A. The left end portion of the rotor shaft 35B protrudes to the left side from the stator 35A. The second lower feed motor 36 has a stator 36A supported to the bed portion 20 and a rotor shaft 36B which rotates inside the stator 36A. The left end portion of the rotor shaft 36B protrudes to the left side from the stator 36A.

[0088] The rotational axis CX1 of the rotor shaft 35B of the first lower feed motor 35 and the rotational axis CX2 of the rotor shaft 36B of the second lower feed motor 36 respectively extend in the left-right direction. The rotational axis CX1 is parallel to the rotational axis CX2.

[0089] The rotor shaft 35B of the first lower feed motor 35 is coupled with the first lower feed shaft 37 via the first coupling 39. The rotor shaft 36B of the second lower feed motor 36 is coupled with the second lower feed shaft 38 via the second coupling 40. The first lower feed shaft 37 and the second lower feed shaft 38 extend in the left-right direction, respectively. The first lower feed shaft 37 is rotatably supported by the first bearing 41. The second lower feed shaft 38 is rotatably supported by the second bearing 42. The first bearing 41 and the second bearing 42 are held by the bed portion 20, respectively.

[0090] The left end portion of the first lower feed shaft 37 is coupled with the first lower feed sprocket 33 in the internal space of the cylinder portion 21. The left end portion of the second lower feed shaft 38 is coupled with the second lower feed sprocket 34 in the internal space of the cylinder portion 21.

[0091] The rotation axis of the first lower feed shaft 37 and the rotation axis of the first lower feed sprocket 33 coincide with the rotation axis CX1 of the first lower feed motor 35. The rotation axis of the second lower feed shaft 38 and the rotation axis of the second lower feed sprocket 34 coincide with the rotation axis CX2 of the second lower feed motor 36.

[0092] The first lower feed motor 35 is driven to rotate the first lower feed shaft 37 in one direction, whereby the first lower feed sprocket 33 is rotated in one direction. By the first lower feed sprocket 33 being rotated in one direction, the first lower feed belt 31 is rotated in one direction. The upper surface of the upper end portion of the first lower feed belt 31, which contacts the lower surface of the sewing object, is moved to the front side by the first lower feed belt 31 being rotated in one direction, whereby the sewing object is fed to the front side by the first lower feed belt 31.

[0093] The second lower feed motor 36 is driven to rotate the second lower feed shaft 38 in one direction, whereby the second lower feed sprocket 34 is rotated in one direction. By the second lower feed sprocket 34 being rotated in one direction, the second lower feed belt 32 is rotated in one direction. The upper surface of the upper end portion of the second lower feed belt 32, which contacts the lower surface of the sewing object, is moved to the front side by the second lower feed belt 32 being rotated in one direction, whereby the sewing object is fed to the front side by the second lower feed belt 32.

[0094] By setting a difference between the rotation speed of the first lower feed motor 35 (the first lower feed sprocket 33) and the rotation speed of the second lower feed motor 36 (the second lower feed sprocket 34), a difference is set between the feed amount (feed speed) of the sewing object based on the first lower feed belt 31 and the feed amount (feed speed) of the sewing object based on the second lower feed belt 32. The second lower feed belt 32 can feed the sewing object at a different feed amount (feed speed) from the feed amount (feed speed) of the sewing object based on the first lower feed belt 31.

[0095] In addition, the first lower feed belt 31 and the second lower feed belt 32 can each be moved in a manner that feeds the sewing object to the rear side.

[0096] In the left-right direction, the first lower feed motor 35 and the second lower feed motor 36 are disposed at different positions. The second lower feed motor 36 is disposed at a position further to the left side than the first lower feed motor 35. In the left-right direction, the position of the first lower feed motor 35 is the same as the position of at least a portion of the body portion 22. In the left-right direction, the position of the second lower feed motor 36 is different from the position of the body portion 22. In a prescribed plane parallel to the upper surface 20A, the first lower feed motor 35 overlaps the body portion 22. The first lower feed motor 35 is disposed directly below the body portion 22. In the prescribed plane parallel to the upper surface 20A, the second lower feed motor 36 does not overlap the body portion 22. The second lower feed motor 36 is disposed at a position further to the left side than the body portion 22. The second lower feed motor 36 is disposed at a position closer to the cylinder portion 21 than the first lower feed motor 35.

[0097] In the front-rear direction, the position of the first lower feed motor 35 is the same as the position of at least a portion of the second lower feed motor 36. In the front-rear direction, the first lower feed motor 35 overlaps at least a portion of the second lower feed motor 36. In the front-rear direction, the position of the stator 35A of the first lower feed motor 35 is the same as the position of at least a portion of the stator 36A of the second lower feed motor 36. In the front-rear direction, the position of the rotor shaft 35B of the first lower feed motor 35 is different from the position of the rotor shaft 36B of the second lower feed motor 36.

[0098] In the up-down direction, the position of the first lower feed motor 35 is the same as the position of at least a portion of the second lower feed motor 36. The first lower feed motor 35 and the second lower feed motor 36 are disposed at the same height.

[0099] <Controller>

[0100] Figure 8 is a block diagram of the controller 50 of the sewing machine 1 according to the embodiment. The sewing machine 1 has the controller 50. The controller 50 includes a computer. The controller 50 controls at least the sewing machine motor 12, the first upper feed motor 15, the second upper feed motor 16, the first lower feed motor 35, and the second lower feed motor 36.

[0101] The controller 50 has a processor 51 such as a CPU (Central Processing Unit), a main memory 52 including a nonvolatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory), a storage device 53, and an input-output interface 54 including an input-output circuit. The functions of the controller 50 are stored in the storage device 53 as a computer program. The processor 51 reads out the computer program from the storage device 53 and expands it in the main memory 52, and performs processing according to the computer program. Further, the computer program can be transmitted to the controller 50 via a network.

[0102] The input-output interface 54 is connected to the sewing machine motor 12, the first upper feed motor 15, the second upper feed motor 16, the first lower feed motor 35, and the second lower feed motor 36, respectively. In addition, an operation panel 55 is connected to the input-output interface 54. The operation panel 55 has a function of a display device and an input device. The operation panel 55 includes a touch panel.

[0103] <Operation of the sewing machine>

[0104] Next, the operation of the sewing machine 1 will be described. The sewing object is a tubular shape. As the sewing object, a sleeve of a garment is exemplified. The user of the sewing machine 1 arranges the sewing object at the sewing position PS so that the tubular portion 21 is inserted into the inside of the tubular sewing object. The sewing object is pressed from the upper side by the pressing member 8 after being arranged at the sewing position PS. The sewing object is clamped by the first upper feed belt 13 and the first lower feed belt 31 on the left side of the sewing position PS. The sewing object is clamped by the second upper feed belt 14 and the second lower feed belt 32 on the left side of the sewing position PS. The first upper feed belt 13 contacts the upper surface of the sewing position PS at a position further to the left than the sewing position PS. The second upper feed belt 14 contacts the upper surface of the sewing position PS at a position further to the right than the sewing position PS. The first lower feed belt 31 contacts the lower surface of the sewing position PS at a position further to the left than the sewing position PS. The second lower feed belt 32 contacts the lower surface of the sewing position PS at a position further to the right than the sewing position PS.

[0105] By operating an unillustrated operation member by the user, sewing of the sewing object is started. The controller 50 controls the sewing machine motor 12 to reciprocate the sewing machine needle 3 in the up-and-down direction and the bobbin case 9 to rotate. In addition, the controller 50 controls the first upper feed motor 15, the second upper feed motor 16, the first lower feed motor 35, and the second lower feed motor 36 respectively to adjust the respective feed amounts based on the first upper feed belt 13, the second upper feed belt 14, the first lower feed belt 31, and the second lower feed belt 32. The controller 50 controls the first upper feed motor 15 and the first lower feed motor 35 to make the feed amount based on the first upper feed belt 13 coincide with the feed amount based on the first lower feed belt 31. The controller 50 controls the second upper feed motor 16 and the second lower feed motor 36 to make the feed amount based on the second upper feed belt 14 coincide with the feed amount based on the second lower feed belt 32.

[0106] Figure 9 is a view for explaining a stitch formed in the sewing object of the embodiment. As shown in Figure 9 In a case where a linear stitch SE is formed in the sewing object, as shown in (A) of

[0107] In a case where a linear stitch SE is formed in the sewing object, as shown in (A) of Figure 9 In a case where a linear stitch SE is formed in the sewing object, as shown in (A) of

[0108] In a case where a linear stitch SE is formed in the sewing object, as shown in (A) of Figure 9 In a case where a linear stitch SE is formed in the sewing object, as shown in (A) of

[0109] The user of the sewing machine 1 can change the shape of the stitch SE by operating the operation panel 55. The controller 50 adjusts the feed amounts based on the first upper feed belt 13 and the first lower feed belt 31 and the feed amounts based on the second upper feed belt 14 and the second lower feed belt 32 based on an operation signal from the operation panel 55.

[0110] <Effects>

[0111] As explained above, in the embodiment, the sewing machine 1 is provided with: a frame 2 having: a bed portion 20 having an upper surface 20A; a cylinder portion 21 protruding from the bed portion 20 to the left side in the left-right direction of a prescribed surface parallel to the upper surface 20A, the dimension in the front-rear direction orthogonal to the left-right direction on the prescribed surface being smaller than the bed portion 20; a body portion 22 extending from the bed portion 20 to the upper side in the up-down direction orthogonal to the prescribed surface; an arm portion 23 extending from the upper end portion of the body portion 22 to the left side in the left-right direction; and a head portion 24 protruding from the arm portion 23 to the lower side; a needle bar 4 supported to the head portion 24 in a movable manner, reciprocating in the up-down direction in a state in which a sewing machine needle 3 holding upper thread is held, in which the sewing machine needle 3 holds the upper thread; a presser member 8 pressing a sewing object arranged at a sewing position PS directly below the sewing machine needle 3; a first lower feed belt 31 which is annular, arranged to the left side of the sewing position PS in the left-right direction, and moves in a manner of feeding the sewing object in the front-rear direction; and a second lower feed belt 32 which is annular, arranged to the right side of the sewing position PS in the left-right direction, and moves in a manner of feeding the sewing object in the front-rear direction independently of the first lower feed belt 31. The first lower feed belt 31 and the second lower feed belt 32 are arranged in the internal space of the cylinder portion 21.

[0112] According to the embodiment, the first lower feed belt 31 and the second lower feed belt 32 are arranged in the internal space of the cylinder portion 21, and thus, as explained above with reference to Figure 9 the shape of the stitch SE is adjusted by adjusting the feed amount of the first lower feed belt 31 and the feed amount of the second lower feed belt 32, respectively. Since the first lower feed belt 31 and the second lower feed belt 32 are arranged in the internal space of the cylinder portion 21, the sewing machine 1 is able to adjust the shape of the stitch SE formed in the sewing object of a sleeve-like cylinder shape.

[0113] The sewing machine 1 is provided with: a bobbin 9 which houses a bobbin case holding a bobbin on which lower thread is wound, and supplies the lower thread to the upper thread. The bobbin 9 is arranged inside the first lower feed belt 31 and inside the second lower feed belt 32 in the internal space of the cylinder portion 21.

[0114] Since the bobbin 9 is supplied to the internal space of the cylinder portion 21, the lower thread is smoothly supplied to the sewing object of a sleeve-like cylinder shape. Since the bobbin 9 is arranged inside the first lower feed belt 31 and inside the second lower feed belt 32, it is possible to suppress the enlargement of the cylinder portion 21.

[0115] The sewing machine 1 is provided with a first lower feed sprocket 33 that moves the first lower feed belt 31 by rotating while supporting the first lower feed belt 31, and a second lower feed sprocket 34 that moves the second lower feed belt 32 by rotating while supporting the second lower feed belt 32. The first lower feed sprocket 33 and the second lower feed sprocket 34 are disposed in the internal space of the cylinder portion 21.

[0116] Since the first lower feed sprocket 33 and the second lower feed sprocket 34 are disposed in the internal space of the cylinder portion 21, the first lower feed belt 31 and the second lower feed belt 32 can rotate while the size of the cylinder portion 21 is suppressed.

[0117] The first lower feed sprocket 33 and the second lower feed sprocket 34 are disposed in the front-rear direction. In the up-down direction, the position of the first lower feed sprocket 33 is the same as the position of at least a part of the second lower feed sprocket 34.

[0118] In the up-down direction, the position of the first lower feed sprocket 33 is the same as the position of at least a part of the second lower feed sprocket 34, so the up-down direction size of the cylinder portion 21 can be suppressed.

[0119] The sewing machine 1 is provided with a first lower feed motor 35 that generates a rotational force for rotating the first lower feed sprocket 33, and a second lower feed motor 36 that generates a rotational force for rotating the second lower feed sprocket 34. The first lower feed motor 35 and the second lower feed motor 36 are disposed in the internal space of the bed portion 20.

[0120] Since the first lower feed motor 35 and the second lower feed motor 36 are disposed in the internal space of the bed portion 20, not in the cylinder portion 21, the size of the cylinder portion 21 can be suppressed.

[0121] In the left-right direction, the first lower feed motor 35 and the second lower feed motor 36 are disposed at different positions.

[0122] In the left-right direction, the first lower feed motor 35 and the second lower feed motor 36 are disposed at different positions, so interference between the first lower feed motor 35 and the second lower feed motor 36 can be suppressed.

[0123] In the front-rear direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36.

[0124] In the front-rear direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36, and thus the front-rear direction of the bed portion 20 can be suppressed from being large-sized. In addition, in the front-rear direction, the stator 35A of the first lower feed motor 35 overlaps the stator 36A of the second lower feed motor 36, and thus the distance in the front-rear direction between the first lower feed sprocket 33 and the second lower feed sprocket 34 can be shortened. That is, in the front-rear direction, the first lower feed sprocket 33 and the second lower feed sprocket 34 can be brought close to each other. Thus, the front-rear direction of the cylinder portion 21 can be suppressed from being large-sized.

[0125] The first lower feed motor 35 is disposed directly below the body portion 22. The second lower feed motor 36 is disposed at a position closer to the cylinder portion 21 than the first lower feed motor.

[0126] The first lower feed motor 35 is disposed directly below the body portion 22, and the second lower feed motor 36 is disposed at a position closer to the cylinder portion 21 than the first lower feed motor, and thus interference between the first lower feed motor 35 and the second lower feed motor 36 can be suppressed.

[0127] In the up-down direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36.

[0128] In the up-down direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36, and thus the up-down direction of the bed portion 20 can be suppressed from being large-sized.

[0129] [Second Embodiment]

[0130] The second embodiment will be described. In the following description, the same reference numerals are attached to the same or equivalent components as those of the above-described embodiment, and the description of the components is simplified or omitted.

[0131] Figure 10 is a bottom view of the lower feed mechanism 11B of the embodiment. Figure 11 is a perspective view of the lower feed mechanism 11B of the embodiment as viewed from the left upper rear side.

[0132] The lower feed mechanism 11B has a first lower feed belt 31, a first lower feed sprocket 33 to which the first lower feed belt 31 is attached, a second lower feed belt 32, and a second lower feed sprocket 34 to which the second lower feed belt 32 is attached.

[0133] Further, the lower feed mechanism 11B has a first input shaft 37A coupled to the first lower feed sprocket 33, a first output shaft 37B coupled to a rotor shaft 35B of the first lower feed motor 35 via a first coupling 39, a second input shaft 38A coupled to the second lower feed sprocket 34, and a second output shaft 38B coupled to a rotor shaft 36B of the second lower feed motor 36 via a second coupling 40. The first input shaft 37A is rotatably supported by a first bearing 41. The second input shaft 38A is rotatably supported by a second bearing 42. The first bearing 41 and the second bearing 42 are supported by the bed portion 20, respectively.

[0134] Further, the lower feed mechanism 11B has a first transmission mechanism 37C that transmits a rotational force of the first output shaft 37B to the first input shaft 37A, and a second transmission mechanism 38C that transmits a rotational force of the second output shaft 38B to the second input shaft 38A.

[0135] The first transmission mechanism 37C includes a belt in a ring shape. The first transmission mechanism 37C includes a so-called endless belt. A first input sprocket 37D is fixed to a right end portion of the first input shaft 37A. A first output sprocket 37E is fixed to a left end portion of the first output shaft 37B. The belt of the first transmission mechanism 37C is hung on the first input sprocket 37D and the first output sprocket 37E.

[0136] The second transmission mechanism 38C includes a belt in a ring shape. The second transmission mechanism 38C includes a so-called endless belt. A second input sprocket 38D is fixed to a right end portion of the second input shaft 38A. A second output sprocket 38E is fixed to a left end portion of the second output shaft 38B. The belt of the second transmission mechanism 38C is hung on the second input sprocket 38D and the second output sprocket 38E.

[0137] In the front-rear direction, the distance between the first input shaft 37A and the second input shaft 38A is shorter than the distance between the first output shaft 37B and the second output shaft 38B.

[0138] The rotational axis CX1 of the first lower feed motor 35 is different from the rotational axis DX1 of the first lower feed sprocket 33. The rotational axis CX2 of the second lower feed motor 36 is different from the rotational axis DX2 of the second lower feed sprocket 34. In the front-rear direction, the distance between the rotational axis DX1 and the rotational axis DX2 is shorter than the distance between the rotational axis CX1 and the rotational axis CX2.

[0139] In the front-rear direction, the position of the first lower feed motor 35 is different from the position of the second lower feed motor 36. In the left-right direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36. In the up-down direction, the position of the first lower feed motor 35 is the same as the position of at least a part of the second lower feed motor 36.

[0140] As explained above, in the embodiment, the lower feed mechanism 11B is provided with: a first input shaft 37A coupled to the first lower feed sprocket 33; a second input shaft 38A coupled to the second lower feed sprocket 34; a first output shaft 37B coupled to the first lower feed motor 35; a second output shaft 38B coupled to the second lower feed motor 36; a first transmission mechanism 37C that transmits the rotational force of the first output shaft 37B to the first input shaft 37A; and a second transmission mechanism 38C that transmits the rotational force of the second output shaft 38B to the second input shaft 38A.

[0141] According to the embodiment, in the front-rear direction, even if the distance between the first lower feed motor 35 (the first output shaft 37B) and the second lower feed motor 36 (the second output shaft 38B) is long, the distance between the first lower feed sprocket 33 (the first input shaft 37A) and the second lower feed sprocket 34 (the second input shaft 38A) can be shortened. Thus, the front-rear direction of the tubular portion 21 can be prevented from being enlarged.

[0142] In addition, the first transmission mechanism 37C that transmits the rotational force of the first output shaft 37B to the first input shaft 37A can also include at least one gear. The second transmission mechanism 38C that transmits the rotational force of the second output shaft 38B to the second input shaft 38A can also include at least one gear.

[0143] [Third Embodiment]

[0144] The third embodiment will be described. In the following description, the same reference numerals are assigned to the same or equivalent constituent elements as those of the above-described embodiments, and the description of the constituent elements is simplified or omitted.

[0145] Figure 12 is a bottom view of the lower feed mechanism 11C of the embodiment. Figure 13 is a left side view of the lower feed mechanism 11C of the embodiment, which corresponds to Figure 12 a B-B line cross-sectional view of Figure 14 is a perspective view of the lower feed mechanism 11C of the embodiment, as viewed from the left upper rear side.

[0146] The lower feed mechanism 11C has: the first lower feed belt 31, the first lower feed sprocket 33 to which the first lower feed belt 31 is hung, the second lower feed belt 32, and the second lower feed sprocket 34 to which the second lower feed belt 32 is hung. The first lower feed belt 31, the first lower feed sprocket 33, the second lower feed belt 32, and the second lower feed sprocket 34 are respectively arranged in the internal space of the tubular portion 21C.

[0147] In the embodiment, the rotational axis DX1 of the first lower feed sprocket 33 coincides with the rotational axis DX2 of the second lower feed sprocket 34.

[0148] Further, the lower feed mechanism 11C has a first lower feed shaft 37 coupled with a rotor shaft 35B of the first lower feed motor 35 via a first coupling 39, and a second lower feed shaft 38 coupled with a rotor shaft 36B of the second lower feed motor 36 via a second coupling 40.

[0149] Figure 15 is a rear view of a portion of the lower feed mechanism 11C of the embodiment. Figure 16 is a sectional view of a portion of the lower feed mechanism 11C of the embodiment. Figure 15 corresponds to a view of the lower feed mechanism 11C of the embodiment as viewed from the rear side. Figure 14 The drawing of the lower feed mechanism 11C of the embodiment is omitted from Figure 15 In the drawing of the lower feed mechanism 11C of the embodiment, the drawing of the first bearing 41 is omitted. Figure 16 corresponds to a view of the lower feed mechanism 11C of the embodiment as viewed from the rear side. Figure 15 is a sectional view of the lower feed mechanism 11C of the embodiment.

[0150] The first lower feed sprocket 33 is fixed to a left end portion of the first lower feed shaft 37. The first lower feed shaft 37 functions as a first input shaft that rotates by a rotational force generated by the first lower feed motor 35.

[0151] The second lower feed sprocket 34 is fixed to a left end portion of a second input shaft 381. The second input shaft 381 rotates by a rotational force generated by the second lower feed motor 36. The second input shaft 381 is cylindrical. The second input shaft 381 is circular cylindrical. The first lower feed shaft 37 is disposed inside the second input shaft 381.

[0152] As shown in Figure 12 and Figure 14 , an output sprocket 382 is fixed to the second lower feed shaft 38. An input sprocket 383 is fixed to the second input shaft 381. A rotational force of the output sprocket 382 is transmitted to the input sprocket 383 via a transmission mechanism 384. The transmission mechanism 384 includes a belt that is hung on the output sprocket 382 and the input sprocket 383. The belt is annular. The belt is a so-called endless belt. Further, the transmission mechanism 384 can include at least one gear.

[0153] As shown in Figure 13 , the kettle 9 is disposed on an upper side of the first lower feed shaft 37.

[0154] The second input shaft 381 is rotatably supported by the first bearing 41. The second lower feed shaft 38 is rotatably supported by the second bearing 42. The first bearing 41 and the second bearing 42 are respectively supported to the bed portion 20.

[0155] When the first lower feed motor 35 is driven and the first lower feed shaft 37 rotates, the first lower feed sprocket 33 fixed to the left end portion of the first lower feed shaft 37 rotates. The first lower feed sprocket 33 rotates on the inner side of the second input shaft 381. By the rotation of the first lower feed sprocket 33, the first lower feed belt 31 moves in a manner to feed the sewing object.

[0156] When the second lower feed motor 36 is driven and the second lower feed shaft 38 rotates, the output sprocket 382 fixed to the second lower feed shaft 38 rotates. The rotation force of the output sprocket 382 is transmitted to the input sprocket 383 via the transmission mechanism 384. The input sprocket 383 rotates by the rotation force of the output sprocket 382. When the input sprocket 383 rotates, the second input shaft 381 to which the input sprocket 383 is fixed rotates. The second input shaft 381 and the first lower feed shaft 37 can relatively rotate. When the second input shaft 381 rotates, the second lower feed sprocket 34 fixed to the left end portion of the second input shaft 381 rotates. By the rotation of the second lower feed sprocket 34, the second lower feed belt 32 moves in a manner to feed the sewing object.

[0157] As described above, according to the embodiment, the second input shaft 381 is cylindrical. The first lower feed shaft 37 (first input shaft) is disposed on the inner side of the second input shaft 381. The second input shaft 381 and the first lower feed shaft 37 can relatively rotate.

[0158] According to the embodiment, the lower feed mechanism 11C is suppressed from being large-sized, and the cylindrical portion 21C is suppressed from being large-sized.

[0159] [Modified Example]

[0160] Figure 17 、 Figure 18 、 Figure 19 and Figure 20 are each a bottom view of the lower feed mechanism of the modified example.

[0161] As shown in Figure 17 , in the left-right direction, the position of the first lower feed motor 35 is different from the position of the second lower feed motor 36. In a prescribed plane parallel to the upper surface 20A, the first lower feed motor 35 overlaps the body portion 22. In the prescribed plane parallel to the upper surface 20A, at least a portion of the second lower feed motor 36 can also overlap the body portion 22.

[0162] As shown in Figure 18 , in the left-right direction, the position of the first lower feed motor 35 can also be the same as the position of the second lower feed motor 36. The first lower feed motor 35 and the second lower feed motor 36 are disposed in the front-rear direction. In a prescribed plane parallel to the upper surface 20A, the first lower feed motor 35 and the second lower feed motor 36 each overlap the body portion 22.

[0163] As Figure 19 indicated, the size of the tub portion 21 can also be larger than that of the bed portion 20 in the left-right direction.

[0164] As Figure 20 indicated, the tub portion 21 can also include a first portion 21X protruding to the left side from the left end portion of the bed portion 20 and a second portion 21Y protruding to the rear side or the front side from the left end portion of the first portion 21X.

Claims

1. A sewing machine, characterized in that, have: A frame having: a bed portion having an upper surface; a cylindrical portion protruding to one side from the bed portion in a first direction on a predetermined plane parallel to the upper surface, wherein the dimension of a second direction orthogonal to the first direction on the predetermined plane is smaller than that of the bed portion; and a body portion extending upward from the bed portion in a third direction orthogonal to the predetermined plane. An arm that extends from the upper end of the body portion toward one side in the first direction; And the head, which protrudes downward from the arm; A needle bar, which is movably supported on the head, reciprocates upward on the third side while holding a sewing machine needle, wherein the sewing machine needle holds the thread. The pressing component presses down on the sewing object located at the sewing position directly below the sewing machine needle; A first feed belt, which is annular, is disposed on one side of the sewing position in the first direction to move the sewing object in a feeding manner in the second direction; and The second lower feed belt, which is loop-shaped, is disposed on the other side of the sewing position in the first direction, and moves independently of the first lower feed belt in a manner that feeds the sewing object in the second direction. The first and second lower feed belts are disposed in the internal space of the cylinder.

2. The sewing machine as described in claim 1, characterized in that, The apparatus includes a vessel housing a spool housing for supplying a lower wire to the upper wire, wherein the spool housing holds a spool wound with the lower wire. The reactor is located within the internal space of the cylindrical section, inside the first lower feed belt and inside the second lower feed belt.

3. The sewing machine as described in claim 1, characterized in that, have: The first lower feed sprocket moves the first lower feed belt by rotating while supporting it; and The second lower feed sprocket moves the second lower feed belt by rotating while the second lower feed belt is supported. The first and second lower feed sprockets are disposed in the internal space of the cylinder.

4. The sewing machine as described in claim 3, characterized in that, The first and second lower feed sprockets are configured in the second direction. In the third direction, the position of the first lower feed sprocket is the same as the position of at least a portion of the second lower feed sprocket.

5. The sewing machine as described in claim 3, characterized in that, have: A first downfeed motor generates a rotational force to rotate the first downfeed sprocket; and The second downfeed motor generates rotational force to rotate the second downfeed sprocket. The first and second down feed motors are disposed in the internal space of the bed section.

6. The sewing machine as described in claim 5, characterized in that, In the first direction, the first down feed motor and the second down feed motor are configured in different positions.

7. The sewing machine as described in claim 6, characterized in that, In the second direction, the position of the first downfeed motor is the same as the position of at least a portion of the second downfeed motor.

8. The sewing machine as described in claim 6, characterized in that, The first downfeed motor is located directly below the body section. The second downfeed motor is positioned closer to the cylinder than the first downfeed motor.

9. The sewing machine as described in any one of claims 5-8, characterized in that, In the third direction, the position of the first down feed motor is the same as the position of at least a portion of the second down feed motor.

10. The sewing machine according to claim 5, characterized in that, have: The first input shaft is connected to the first lower feed sprocket; The second input shaft is connected to the second lower feed sprocket; The first output shaft is connected to the first down feed motor; The second output shaft is connected to the second downfeed motor; A first transmission mechanism transmits the rotational force of the first output shaft to the first input shaft; as well as The second transmission mechanism transmits the rotational force of the second output shaft to the second input shaft.

11. The sewing machine according to claim 5, characterized in that, have: A first input shaft, fixed to the first lower feed sprocket, rotates by the rotational force generated by the first lower feed motor; and The second input shaft is fixed to the second lower feed sprocket and rotates by the rotational force generated by the second lower feed motor. The second input shaft is cylindrical. The first input shaft is disposed inside the second input shaft.

12. The sewing machine according to claim 11, characterized in that, The apparatus includes a vessel housing a spool housing for supplying a lower wire to the upper wire, wherein the spool housing holds a spool wound with the lower wire. The vessel is positioned above the first input shaft.

13. The sewing machine according to claim 1, characterized in that, have: A first upper feed belt, which is looped, is disposed on one side of the sewing position in the first direction so that the sewing object moves in a feeding manner in the second direction; as well as The second upper feed belt, which is loop-shaped, is disposed on the other side of the sewing position in the first direction, and moves independently of the first upper feed belt in a manner that feeds the sewing object in the second direction. The first and second upper feed belts are supported on the head.

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