Sewing machine

Abstract

The invention provides a sewing machine which can reduce the burden of replacing a belt. The sewing machine (100) comprises a feeding device (40), the feeding device (40) feeds an object to be sewn through conveying belts (41, 42) abutting against the object to be sewn, and in the sewing machine (100), conveying force is applied to the conveying belts (41, 42) through power transmission belts (411, 421) from motors (45, 46) serving as driving sources for feeding the object to be sewn. By dividing the belt into the conveying belt and the power transmission belt, for example, even if the distance from the motor to the needle dropping position is far away, the length of each belt can be shortened, so that the replacement operation becomes easy.

Description

Technical Field

[0001] The present invention relates to a sewing machine with belt feeding. Background Art

[0002] In a conventional sewing machine having a belt that feeds the sewn material on a needle plate from above, an endless ring-shaped belt is stretched long and laid between a pulley of a motor serving as a driving source, a belt guide, and a roller of a belt feed foot near a needle drop position (see, for example, Patent Document 1).

[0003] [Prior art literature] [Patent Document] [Patent Document 1] Japanese Patent Application Publication No. 2006-158497 Summary of the invention [Problems to be solved by the invention] As described above, in the case of a belt span and a long path, when replacing the belt, the operation of removing from the entire path or installing on the entire path becomes very complicated, and the workload is heavy. This becomes particularly significant when part or all of the path on the motor side becomes the inner side of the frame or cover.

[0004] An object of the present invention is to facilitate belt replacement.

[0005] [Technical means to solve the problem] The present invention is a sewing machine comprising a feeding device, wherein the feeding device feeds the sewn object through a conveyor belt abutting against the sewn object, and the sewing machine is characterized in that: A conveying force is applied to the conveyor belt from a motor serving as a driving source for feeding the sewn article via a power transmission belt.

[0006] [Effects of the Invention] The sewing machine of the present invention can easily replace the belt due to the above-mentioned structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a rear view of the sewing machine which is an embodiment of the invention.

[0008] Figure 2 It is the left side view of the sewing machine.

[0009] Figure 3 It is a three-dimensional diagram of a sewing machine.

[0010] Figure 4 It is a perspective view showing the upper surface of the left end portion of the sewing machine base portion in which the presser foot is omitted.

[0011] Figure 5It is a three-dimensional view of the guide frame of the lower feed mechanism.

[0012] Figure 6 It is a three-dimensional diagram of the feeding mechanism in which the four conveyor belts are in a front-rear differential feeding state.

[0013] Figure 7 It is a three-dimensional diagram of the feeding mechanism in which the four conveyor belts are in a left-right differential feeding state.

[0014] Figure 8 This is a perspective view of the periphery of a cloth pressing mechanism that presses the sewn material from above on the needle plate.

[0015] Fig. 9 It is from Figure 8 A three-dimensional view of the periphery of the cloth pressing mechanism viewed from different directions.

[0016] Fig.10 This is a perspective view showing an enlarged view of the periphery of a pair of third tension rollers.

[0017] Fig.11 This is a side view of one of the third tensioning rollers viewed from the left.

[0018] Fig.12 This is a perspective view showing an example in which a needle hole is directly formed in a needle plate and showing the upper surface of the left end portion of a sewing machine base.

[0019] [Explanation of Symbols] 11: Stitches 12: Needle bar 13: Needle hole (needle drop position) 20: Lower feeding mechanism (feeding device) 21: Rear lower left belt (conveyor belt) 22: Front left lower belt (conveyor belt) 23: Front right lower belt (conveyor belt) 24: Rear right lower belt (conveyor belt) 25: First Motor 26: Second Motor 31: First pulley 32: Second pulley 33: First pressurizing mechanism 34: Second pressurizing mechanism 40: Upper feeding mechanism (feeding device) 41: Upper left belt 42: Upper right belt 43, 44: With guide 45: Upper left motor (conveyor belt) 46: Upper right motor (conveyor belt) 47: Guidance Agency 49: The third tension roller (tension adjustment mechanism) 100: Sewing machine 101: Needle plate 331: Left pressure roller 332: Right pressure roller 341: Left pressure roller 342: Right pressure roller 411, 421: Power transmission belt 431: Axis 432, 442: Feed roller 452, 462: Motor pulley 471: First tension roller 472: Second tension roller 481, 482: Relay roller 491, 492: rolling element 493: Shaft component (eccentric shaft) 493a: shaft 493b: Eccentric support shaft DETAILED DESCRIPTION [Overview of Embodiments of the Invention] Hereinafter, the sewing machine 100 as an embodiment of the present invention will be described in detail.

[0020] Figure 1 1 shows a rear view of the sewing machine 100, Figure 2 1 shows a left side view of the sewing machine 100, Figure 3 A perspective view showing the sewing machine 100 is shown.

[0021] The following is the sewn material (refer to Fig.12 ) is set as "front", and the upstream side of the feeding direction is set as "rear". When facing forward, the left hand side is set as "left", the right hand side is set as "right", the vertically above is set as "up", and the vertically below is set as "down". The front-to-back direction, the left-right direction, and the up-down direction are orthogonal to each other.

[0022] In the following description, it is assumed that the sewing machine 100 is installed on a horizontal plane, and the front-rear direction and the left-right direction are horizontal.

[0023] As the sewing machine 100 as the embodiment of the present invention, a so-called lockstitch sewing machine is exemplified.

[0024] The sewing machine 100 includes a sewing machine frame 110, a needle up-and-down moving mechanism, a lower feeding mechanism 20, an upper feeding mechanism 40, a cloth pressing mechanism 70 as a pressing mechanism, and a shuttle mechanism.

[0025] The needle vertical movement mechanism imparts a vertical movement action to the sewing needle 11 .

[0026] The lower feeding mechanism 20 applies a feeding action to the workpiece on the needle plate 101 from below.

[0027] The upper feeding mechanism 40 applies a feeding operation to the sewn material on the needle plate 101 from above.

[0028] The cloth pressing mechanism 70 applies a pressing pressure to the sewn material on the needle plate 101 .

[0029] The shuttle mechanism captures the thread loop of the upper thread from the sewing needle 11 and winds the lower thread to form a stitch.

[0030] In addition, the sewing machine 100 includes various structures such as a balance mechanism and a thread adjuster included in a general lockstitch sewing machine. Since these are well-known components, their description is omitted.

[0031] [Sewing machine stand] The sewing machine frame 110 supports or accommodates various structures of the sewing machine 100 .

[0032] The sewing machine frame 110 includes a sewing machine base portion 111 , a vertical cylinder portion 112 , and a sewing machine arm portion 113 .

[0033] The sewing machine base 111 is located at the lower portion of the sewing machine 100 and extends in the left-right direction.

[0034] The vertical cylinder portion 112 is provided upright from the right end portion of the sewing machine base portion 111 .

[0035] The sewing machine arm portion 113 extends toward the left from the upper end portion of the vertical cylinder portion 112 .

[0036] [Needle up and down movement mechanism] Figure 4 It is a perspective view showing the upper surface of the left end portion of the sewing machine base portion 111 in which a presser foot described later is omitted from the illustration.

[0037] The needle vertical movement mechanism includes an upper shaft which is disposed inside the sewing machine arm portion 113 in a state along the left-right direction and is rotationally driven by the sewing machine motor.

[0038] Furthermore, if Figure 1 to Figure 4 As shown, the needle up and down movement mechanism includes: a needle bar 12, which holds the sewing needle 11 at the lower end; and a crank mechanism, which converts the rotation force of the upper shaft into a reciprocating driving force for up and down movement and transmits it to the needle bar.

[0039] In addition, the upper shaft and the crank mechanism are well known, and thus illustration thereof is omitted.

[0040] The needle bar 12 extends in the up-down direction and is supported at the lower left end of the sewing machine arm 113 so as to be able to move up and down.

[0041] The sewing needle 11 is held at the lower end of the needle bar 12 and moves up and down together with the needle bar 12. A needle plate 101 including a horizontal flat plate is provided below the needle bar 12 on the upper surface of the sewing machine base 111.

[0042] Furthermore, a composite opening 102 is formed at the needle drop position of the sewing needle 11 relative to the needle plate 101. In the composite opening 102 of the needle plate 101, the needle hole member 30 having the needle hole 13 and the rear left lower belt 21, the front left lower belt 22, the front right lower belt 23, and the rear right lower belt 24 of the lower feed mechanism 20 described later are arranged to be exposed upward. That is, the composite opening 102 is a shape in which the needle hole member 30 and the plurality of rectangular openings in which the lower belts 21 to 24 are exposed are integrally composited.

[0043] [Shuttle mechanism] like Figure 2 and Figure 3 As shown, the shuttle mechanism includes an inner shuttle 14 and an outer shuttle 15 provided below the needle hole member 30 of the needle plate 101 , and a shuttle shaft (not shown) for rotating the outer shuttle 15 .

[0044] The shuttle shaft is supported rotatably in the horizontal direction in the sewing machine base 111. The shuttle shaft is rotated about the horizontal axis at twice the speed of the upper shaft via a gear mechanism or a belt mechanism.

[0045] The inner shuttle 14 is accommodated inside the outer shuttle 15. Furthermore, the inner shuttle 14 accommodates a thread spool (not shown) for supplying a lower thread therein.

[0046] The outer shuttle 15 is connected to the left end of the shuttle shaft and rotates around the inner shuttle 14. The inner shuttle 14 is restricted from rotating together with the outer shuttle 15. The outer shuttle 15 has a tip on the outer periphery for catching the thread loop of the upper thread from the sewing needle 11. The outer shuttle 15 can catch the thread loop of the upper thread with the tip by rotating and pass the lower thread drawn from the inner side of the inner shuttle 14.

[0047] The outer shuttle 15 and the inner shuttle 14 are arranged in a stored state inside a substantially cylindrical guide frame 29 of a lower feed mechanism 20 to be described later.

[0048] [Lower feed mechanism] Figure 5 is a perspective view of the guide frame 29 of the lower feed mechanism 20, Figure 6 and Figure 7 It is a perspective view of the lower feeding mechanism 20 . Figure 6 and Figure 7 The following diagram shows a case where the installation states of the lower belts 21 to 24 described later are different.

[0049] The following is based on Figure 1 to Figure 7 The lower feeding mechanism 20 will be described in detail.

[0050] As shown in the drawings, the lower feeding mechanism 20 includes lower belts 21 to 24 as conveying belts, a first motor 25 , a second motor 26 , a rotating shaft 27 , a rotating shaft 28 , a first pulley 31 , and a second pulley 32 .

[0051] Furthermore, the lower feeding mechanism 20 includes a guide frame 29 for guiding the lower belts 21 to 24 so as to contact the lower surface of the sewn object, a first pressing mechanism 33 , and a second pressing mechanism 34 .

[0052] The first motor 25 and the second motor 26 are motors capable of arbitrarily controlling the amount of movement, such as stepping motors or servo motors. Encoders may also be provided in conjunction with each motor 25 and 26. The first motor 25 and the second motor 26 are arranged in a front-to-back manner on the inner side of the right end of the sewing machine base 111, with the output shaft facing leftward.

[0053] A first pulley 31 is connected to the output shaft of the first motor 25 on the front side via a rotating shaft 27 .

[0054] A second pulley 32 is connected to the output shaft of the second motor 26 on the rear side via the rotating shaft 28 .

[0055] The rotating shafts 27 and 28 are both parallel to the left-right direction and are rotatably supported in the sewing machine base 111 .

[0056] The first pulley 31 and the second pulley 32 are supported rotatably around axes along the left and right directions in the left end of the sewing machine base 111. The first pulley 31 and the second pulley 32 are rotated by the first motor 25 and the second motor 26 via the rotating shaft 27 and the rotating shaft 28, respectively.

[0057] The first pulley 31 and the second pulley 32 are arranged to overlap when viewed from the front-rear direction, that is, at the same height and at the same position in the left-right direction. In addition, the first pulley 31 is arranged on the front side of the second pulley 32.

[0058] The first pulley 31 and the second pulley 32 can be laid over all of the lower belts 21 , 22 , 23 , and 24 arranged in parallel in the left-right direction.

[0059] That is, the first pulley 31 has a left groove 311 for laying the rear left lower belt 21 and the front left lower belt 22 , and a right groove 312 for laying the front right lower belt 23 and the rear right lower belt 24 , on its outer peripheral surface.

[0060] The second pulley 32 has a left groove 321 for laying the rear left lower belt 21 and the front left lower belt 22 , and a right groove 322 for laying the front right lower belt 23 and the rear right lower belt 24 , on its outer peripheral surface.

[0061] The widths of the lower belts 21 to 24 are equal, and the left grooves 311 and 321 and the right grooves 312 and 322 all have at least a width corresponding to two belts.

[0062] Thus, each of the lower belts 21 to 24 can be installed by appropriately selecting the first pulley 31 and the second pulley 32 .

[0063] Each of the lower belts 21 , 22 , 23 , 24 is in an endless ring shape and is mounted between the guide frame 29 and the first pulley 31 or between the guide frame 29 and the second pulley 32 .

[0064] In addition, the lower belts 21, 22, 23, and 24 are arranged in order from left to right.

[0065] like Figure 2 As shown, the guide frame 29 (guide member) is arranged to be substantially aligned with the pulleys 31 and 32 in the left-right direction and between the pulleys 31 and 32 in the front-back direction. Furthermore, the guide frame 29 is arranged above the pulleys 31 and 32 and directly below the needle plate 101 .

[0066] like Figure 5 As shown, the guide frame 29 includes a bracket portion 295 for being fixed in the sewing machine base portion 111 and a cylindrical main body portion 296 for guiding each of the lower belts 21 to 24.

[0067] The guide frame 29 is disposed directly below the needle plate 101 with the central axis of the main body 296 facing the left-right direction.

[0068] A fitting groove 297 along the front-rear direction is formed at the left-right center of the outer peripheral surface upper portion of the main body 296. A pinhole member 30 elongated in the front-rear direction is arranged inside the fitting groove 297. The pinhole member 30 has a pinhole 13 penetrating vertically formed at the needle drop position.

[0069] The needle hole member 30 is connected to a needle up-and-down moving mechanism (not shown), which uses the sewing machine motor as a driving source and moves up and down in the same cycle as the sewing needle 11. The needle hole member 30 moves up and down in a phase opposite to the sewing needle 11 through the needle up-and-down moving mechanism. That is, the formation surface of the needle hole 13 of the needle hole member 30 is at the highest position at the same height as or slightly higher than the upper surface of the needle plate 101 when the phase becomes the lower dead point of the sewing needle 11, and is at the lowest position that is most descended from the upper surface of the needle plate 101 when the phase becomes the upper dead point of the sewing needle 11.

[0070] In addition, the main body 296 slides each lower belt 21 to 24 in the circumferential direction on the upper part of its outer peripheral surface to feed the sewn material. Therefore, the first guide part 291, the second guide part 292, the third guide part 293, and the fourth guide part 294 for guiding each lower belt 21 to 24 are provided on the upper part of the outer peripheral surface of the main body 296.

[0071] The first guide portion 291 is disposed at the left rear of the needle hole 13 , the second guide portion 292 is disposed at the left front of the needle hole 13 , the third guide portion 293 is disposed at the right front of the needle hole 13 , and the fourth guide portion 294 is disposed at the right rear of the needle hole 13 .

[0072] Each guide portion 291 to 294 is a convex strip extending in the front-to-back direction, and its width in the left-to-right direction is equal to or slightly wider than that of each lower belt 21 to 24. The rear end portion of each guide portion 291 to 294 forms a slope whose protrusion amount toward the outside in the radial direction relative to the outer peripheral surface of the main body 296 gradually increases toward the front. In addition, the front end portion of each guide portion 291 to 294 forms a slope whose protrusion amount toward the outside in the radial direction relative to the outer peripheral surface of the main body 296 gradually decreases toward the front.

[0073] The first guide portion 291 is located on the left side of the pinhole 13 and is located on the rear side of the center of the pinhole 13 over substantially the entire length.

[0074] The first guide portion 291 has a flat and horizontal guide surface 291a ( Figure 5 The guide surface 291a is configured to face the composite opening portion 102 of the needle plate 101 when viewed from above.

[0075] Furthermore, the guide surface 291 a is set so that the outer side surface of the rear left lower belt 21 slidingly passing thereon is slightly higher than the upper surface of the needle plate 101 .

[0076] The guide surface 291 a is formed so that its front end portion is located slightly behind the center of the needle hole 13 , and the rear left lower belt 21 abuts against the workpiece at a position further behind the center of the needle hole 13 .

[0077] The second guide portion 292 is located on the left side of the pinhole 13 and on the right side of the first guide portion 291 , and is located on the front side of the center of the pinhole 13 over substantially the entire length.

[0078] The second guide portion 292 has a flat and horizontal guide surface 292a ( Figure 5 The guide surface 292a is configured to face the composite opening portion 102 of the needle plate 101 when viewed from above.

[0079] Moreover, the guide surface 292 a is set so that the outer side surface of the front left lower belt 22 that slides and passes thereon is slightly higher than the upper surface of the needle plate 101 .

[0080] The guide surface 292 a is formed so that its rear end portion is located slightly forward of the center of the needle hole 13 , and the front left lower belt 22 abuts against the workpiece further forward than the center of the needle hole 13 .

[0081] The third guide portion 293 is located on the right side of the pinhole 13 and is located on the front side of the center of the pinhole 13 over substantially the entire length.

[0082] The third guide portion 293 has a flat and horizontal guide surface 293a ( Figure 5 The guide surface 293a is configured to face the composite opening portion 102 of the needle plate 101 when viewed from above.

[0083] Moreover, the guide surface 293 a is set so that the outer side surface of the front right lower belt 23 slidingly passing thereon is slightly higher than the upper surface of the needle plate 101 .

[0084] The guide surface 293 a is formed so that its rear end portion is located slightly forward of the center of the needle hole 13 , and the front right lower belt 23 abuts against the workpiece further forward than the center of the needle hole 13 .

[0085] The fourth guide portion 294 is located on the right side of the pinhole 13 and the third guide portion 293 and is located on the rear side of the center of the pinhole 13 over substantially the entire length.

[0086] The fourth guide portion 294 has a flat and horizontal guide surface 294a ( Figure 5 The guide surface 294a is configured to face the composite opening portion 102 of the needle plate 101 when viewed from above.

[0087] Moreover, the guide surface 294 a is set so that the outer side surface of the rear right lower belt 24 that slides and passes thereon is slightly higher than the upper surface of the needle plate 101 .

[0088] The guide surface 294 a is formed so that its front end portion is located slightly behind the center of the needle hole 13 , and the rear right lower belt 24 abuts against the workpiece further behind the center of the needle hole 13 .

[0089] The guide surfaces 291a and 294a are arranged at the rear side of the center of the needle hole 13, and the guide surfaces 292a and 293a are arranged at the front side of the center of the needle hole 13. Therefore, when a speed difference (transport amount difference) is set between the rear left lower belt 21 and the rear right lower belt 24 on the rear side and the front left lower belt 22 and the front right lower belt 23 on the front side, each lower belt 21 to 24 does not interfere with each other, and a transport force based on the front and rear feed speed difference (transport amount difference) can be applied to the sewn material. Therefore, it is possible to form a stitch as the target in the differential feed in the front and rear directions, and to achieve an improvement in sewing quality.

[0090] The first pressing mechanism 33 applies tension to all of the lower belts 21 to 24 that are stretched between the guide frame 29 and the first pulley 31 to suppress the occurrence of slack.

[0091] like Figure 2 , Figure 3 and Figure 6 As shown, the first pressing mechanism 33 includes a left pressing roller 331 , a right pressing roller 332 , a support plate 333 , and a base block 334 .

[0092] The support plate 333 is in the shape of a flat plate that is long along the front-rear and top-bottom directions, and is supported on the base block 334 in a state where the longitudinal direction thereof faces the front obliquely upward direction.

[0093] Furthermore, the support plate 333 supports the left pressure roller 331 and the right pressure roller 332 concentrically and rotatably using the left and right surfaces of the upper end thereof. The support plate 333 is arranged so that the left pressure roller 331 and the right pressure roller 332 abut against the outer side surface of the belt spanning between the guide frame 29 and the first pulley 31 from the rear and lower part.

[0094] The base block 334 is shared by the second pressurizing mechanism 34 described later, and supports the structures of the first pressurizing mechanism 33 and the second pressurizing mechanism 34. The base block 334 is fixedly mounted below the guide frame 29 in the sewing machine bed 111.

[0095] The support plate 333 has a long hole along its length direction, and is fastened to the base block 334 by two bolts inserted into the long hole. The length direction of the support plate 333 is oriented in a direction substantially orthogonal to the belt mounted on the first pulley 31. Therefore, by loosening the bolts and moving the support plate 333 along the long hole, the pressing force of the left pressure roller 331 and the right pressure roller 332 on the belt can be adjusted. In other words, the tension of the belt spanning between the guide frame 29 and the first pulley 31 can be adjusted.

[0096] The left pressure roller 331 and the right pressure roller 332 have the same outer diameter and are supported by the support plate 333 so as to be rotatable around the same axis along the left-right direction. In addition, the left and right widths of the left and right pressure rollers 331 and 332 are both twice or more than the width of each lower belt 21 to 24.

[0097] Thus, the left pressure roller 331 can come into contact with any one of the rear left lower belt 21 and the front left lower belt 22 that are stretched between the guide frame 29 and the first pulley 31 .

[0098] Similarly, the right pressure roller 332 may come into contact with any one of the front right lower belt 23 and the rear right lower belt 24 which are stretched between the guide frame 29 and the first pulley 31 .

[0099] The second pressing mechanism 34 applies tension to all of the lower belts 21 to 24 that are stretched between the guide frame 29 and the second pulley 32 to suppress the occurrence of slack.

[0100] like Figure 2 , Figure 3 and Figure 6 As shown, the second pressing mechanism 34 includes a left pressing roller 341 , a right pressing roller 342 , a support plate 343 , and the base block 334 .

[0101] The support plate 343 has the same structure as the support plate 333 , and is supported on the base block 334 in a state where the longitudinal direction thereof faces the rearward and upward direction.

[0102] The support plate 343 supports the left pressure roller 341 and the right pressure roller 342 concentrically and rotatably using the left and right surfaces of the upper end of the support plate 343. The support plate 343 is arranged so that the left pressure roller 341 and the right pressure roller 342 abut against the outer side surface of the belt spanning between the guide frame 29 and the second pulley 32 from the rear and upper part.

[0103] The support plate 343 also has a long hole, and the support plate 343 can be moved along the long hole. Thus, the pressing force of the left pressure roller 341 and the right pressure roller 342 on the belt mounted on the second pulley 32 can be adjusted. Therefore, the tension of the belt between the guide frame 29 and the second pulley 32 can be adjusted.

[0104] The left pressure roller 341 and the right pressure roller 342 have the same outer diameter and are supported by the support plate 343 so as to be rotatable around the same axis along the left and right directions. In addition, the left and right pressure rollers 341 and 342 have a width twice or more than that of each lower belt 21 to 24.

[0105] Thus, the left pressure roller 341 can come into contact with any one of the rear left lower belt 21 and the front left lower belt 22 that are stretched between the guide frame 29 and the second pulley 32 .

[0106] Similarly, the right pressure roller 342 may come into contact with any one of the front right lower belt 23 and the rear right lower belt 24 which are stretched between the guide frame 29 and the second pulley 32 .

[0107] The left pressure roller 331 of the first pressure mechanism 33 and the left pressure roller 341 of the second pressure mechanism 34 can both abut against the rear left lower belt 21 and the front left lower belt 22. Similarly, the right pressure roller 332 of the first pressure mechanism 33 and the right pressure roller 342 of the second pressure mechanism 34 can both abut against the front right lower belt 23 and the rear right lower belt 24.

[0108] Therefore, even when each of the lower belts 21 to 24 is stretched over any one of the first pulley 31 and the second pulley 32 , tension is applied by any one of the first pressurizing mechanism 33 and the second pressurizing mechanism 34 .

[0109] Figure 6 The figure shows a state where the front left lower belt 22 and the front right lower belt 23 feeding the front side of the needle drop position are stretched on the first pulley 31, and the rear left lower belt 21 and the rear right lower belt 24 feeding the rear side are stretched on the second pulley 32.

[0110] Figure 7 The figure shows a state where the rear left lower belt 21 and the front left lower belt 22 fed to the left side of the needle drop position are stretched over the first pulley 31 , and the front right lower belt 23 and the rear right lower belt 24 are stretched over the second pulley 32 .

[0111] When the bolts are loosened and the pressure rollers 331 , 332 , 341 , 342 are retracted, the lower belts 21 to 24 can be easily removed from the pulleys 31 , 32 and re-mounted.

[0112] Therefore, it is easy to select and Figure 6 Sewing and Figure 7 Sewing in the erected state.

[0113] For example, in Figure 6 In the erected state (set to the front and rear differential feeding state), the so-called pleating sewing can be performed in which the part closer to the front side than the needle drop position is fed faster than the part closer to the rear side than the needle drop position.

[0114] In addition, in the front-rear differential feeding state, it is also possible to sew by feeding the part on the front side of the needle drop position more slowly than the part on the rear side of the needle drop position, thereby applying tension to the sewn material.

[0115] exist Figure 7 In the setting state (set to the left and right differential feed state), if the left side is quickly fed, right-turn curve sewing can be performed, and if the right side is quickly fed, left-turn curve sewing can be performed.

[0116] In addition, since the curvature can be changed according to the size of the speed difference (transport amount difference) between the left and right sides, various curved sewing can be performed.

[0117] [Cloth pressing mechanism] Figure 8 1 is a perspective view of a cloth pressing mechanism 70 as a pressing mechanism for pressing a sewn object from above on a needle plate 101. Fig. 9 It is from Figure 8 A perspective view of the cloth pressing mechanism 70 viewed from different directions.

[0118] The cloth pressing mechanism 70 includes a presser foot 71 , a press rod 72 , a mounting base 74 , a press motor (not shown), and a press height detection unit (not shown).

[0119] The pressure bar 72 is disposed in front of the needle bar 12 and is supported in the interior of the sewing machine arm portion 113 so as to be movable up and down in a state along the up and down direction.

[0120] The upper end of the press rod 72 is pushed downward by a press spring (not shown) inside the sewing machine arm 113. The expansion and contraction amount of the press spring can be adjusted by a press motor (not shown) that can arbitrarily control the amount of movement. Therefore, by controlling the press motor, the pressing pressure of the presser foot 71 can be arbitrarily set.

[0121] In addition, the pressing motor also provides a lifting action for switching the pressing height for the presser foot 71 to press the workpiece on the needle plate 101 and the release height to move away upward.

[0122] In addition, a pressing height detection unit (not shown) for detecting the height of the pressing rod 72 is provided. Therefore, after the pressing pressure of the presser foot 71 is set to a predetermined value, when the height of the presser foot 71 changes due to the change in the thickness of the sewn material, the pressing pressure can be maintained at a certain set value by controlling the pressing motor in such a way that the expansion and contraction amount of the pressing spring does not change.

[0123] The presser foot 71 is attached to the lower end portion of the press rod 72 via a mounting base 74 .

[0124] The rear portion of the mounting platform 74 is an insertion portion 741 through which the pressure rod 72 can be inserted and held, and the mounting platform 74 is fixed to the pressure rod 72 .

[0125] The front portion of the mounting platform 74 has a pair of forked extension arms 742. Each extension arm 742 faces forward, bends midway, and extends downward.

[0126] A part of the structure of the upper feed mechanism 40 described later is supported by the pair of extending arm portions 742 of the mounting table 74 and the presser foot 71 .

[0127] The presser foot 71 is arranged on the composite opening 102 of the needle plate 101. The presser foot 71 presses the sewn article from above so that the conveying force based on the lower belts 21 to 24 is appropriately transmitted to the sewn article. In addition, the presser foot 71 supports the upper left belt 41 and the upper right belt 42 via the belt guides 43 and 44 of the upper feed mechanism 40 so that they can be conveyed. Moreover, the presser foot 71 also has the function of pressing the upper belts 41 and 42 against the sewn article so that the conveying force thereof is appropriately transmitted to the sewn article.

[0128] like Figure 8-Figure 9 As shown, the presser foot 71 includes a bottom plate 711 for pressing a workpiece from above and a connecting portion 712 mounted on the lower end of a mounting base 74 .

[0129] The bottom plate 711 has a so-called boat shape in which the bottom surface is smooth and the upstream side (rear end portion) in the cloth feeding direction is tilted upward.

[0130] The connecting portion 712 is vertically disposed on the upper surface of the front end of the bottom plate 711, and is connected to the bottom plate 711 in a manner that allows it to slightly swing around an axis along the left-right direction. The upper portion of the connecting portion 712 abuts against the bottom surface of the mounting platform 74, and is fixed to the left side surface thereof by, for example, screwing. In addition, the connecting portion 712 may be joined to the mounting platform 74 by welding or the like, or may be composed of a single component in which the connecting portion 712 and the mounting platform 74 are integrated.

[0131] [Upper feed mechanism] like Figure 1 , Figure 2 , Figure 8 , Fig. 9 As shown, the upper feeding mechanism 40 includes: an upper left belt 41 and an upper right belt 42 serving as conveying belts, the left and right belt guides 43, a belt guide 44, an upper left motor 45 serving as a driving source for belt feeding of the upper left belt 41, an upper right motor 46 serving as a driving source for belt feeding of the upper right belt 42, a power transmission belt 411 for transmitting the conveying force from the upper left motor 45 to the upper left belt 41, a power transmission belt 421 for transmitting the conveying force from the upper right motor 46 to the upper right belt 42, and a guiding mechanism 47 for guiding the upper left belt 41, the upper right belt 42 and the power transmission belts 411 and 412.

[0132] The upper feed mechanism 40 also includes a cover (not shown) that covers the upper left motor 45 , the upper right motor 46 , and the middle of the guide arm 475 of the guide mechanism 47 .

[0133] The left and right belt guides 43 and 44 are mounted on the left and right sides of the presser foot 71 .

[0134] The belt guides 43 and 44 are rotatably mounted on left and right side surfaces of the lower portion of the connection portion 712 of the presser foot 71 via a support shaft 431 extending in the left-right direction.

[0135] Each belt guide 43, 44 is shaped as follows: when viewed from the side, the front end extends obliquely upward toward the front, the front end is closest to the needle plate 101, and the rear end floats obliquely upward toward the rear. In addition, each belt guide 43, 44 includes a feed roller 432 and a feed roller 442 at the rear end that can rotate along an axis in the left-right direction.

[0136] The left and right endless ring-shaped upper belts 41 and 42 are guided so as to pass between the left and right belt guides 43 and 44 and the side surface of the presser foot 71. That is, the left and right upper belts 41 and 42 are guided so as to be folded downward along the outer circumference from the upper part of the feed rollers 432 and 442 and to move forward toward the part of each belt guide 43 and 44 closest to the needle plate 101, and then pass forward in the obliquely upward direction. When each upper belt 41 and 42 moves forward along the part of each belt guide 43 and 44 closest to the needle plate 101, it contacts the sewn material on the needle plate 101 and is fed forward.

[0137] In addition, the contact position of the workpiece of the left upper belt 41 overlaps with the contact position of the workpiece of the front left lower belt 22 in a plan view, and the workpiece is fed so as to be sandwiched by these belts.

[0138] Similarly, the contact position of the workpiece of the right upper belt 42 overlaps with the contact position of the workpiece of the front right lower belt 23 in a plan view, and the workpiece is fed so as to be sandwiched by these belts.

[0139] As described above, each of the belt guides 43 and 44 is axially supported on the presser foot 71 by the support shaft 431. One ends of the tension springs 433 and 443 as springs are connected to the shafts 434 and 444 provided at the front ends of each of the belt guides 43 and 44. The other ends of each of the tension springs 433 and 443 are connected to the shafts 713 and 714 provided at the left and right side portions behind the upper end of the presser foot 71, respectively, to apply tension to the front ends of each of the belt guides 43 and 44 to the upper side.

[0140] Therefore, the rear end side of each belt guide 43, 44 is rotated downward, and the upper belts 41, 42 that move forward along the portion closest to the needle plate 101 are given a pressing force toward the needle plate 101. Therefore, the upper belts 41, 42 are given a pressing force toward the sewn object on the needle plate 101.

[0141] The upper left motor 45 and the upper right motor 46 use motors whose rotation speed can be controlled, such as a DC motor, an AC motor, a stepping motor, etc. An encoder may be provided in conjunction with each of the motors 45 and 46 .

[0142] The upper left motor 45 is supported on the front side of the left end portion of the sewing machine arm 113 via a motor bracket 451 in a state where the output shaft is directed to the left.

[0143] The upper right motor 46 is supported above the upper left motor 45 via a motor bracket 451 on the front side of the left end portion of the sewing machine arm 113 in a state where the output shaft is directed to the left.

[0144] Furthermore, a motor pulley 452 is attached to the output shaft of the upper left motor 45 , and one end of the power transmission belt 411 is wound around the motor pulley 452 .

[0145] Furthermore, a motor pulley 462 is attached to the output shaft of the upper right motor 46 , and one end of the power transmission belt 421 is wound around the motor pulley 462 .

[0146] The power transmission belt 411 and the upper left belt 41 are both endless loops, and one end of the power transmission belt 411 in a drawn loop state is mounted on the motor pulley 452 of the upper left motor 45, and the other end is mounted on the relay roller 481 described later. In addition, one end of the drawn loop state of the upper left belt 41 is mounted on the relay roller 481, and the other end is mounted on the feed roller 432 at the rear end of the belt guide 43.

[0147] The power transmission belt 421 and the upper right belt 42 are also endless loops, and one end of the power transmission belt 421 in a drawn loop state is mounted on the motor pulley 462 of the upper right motor 46, and the other end is mounted on the relay roller 482 described later. In addition, one end of the upper right belt 42 in a drawn loop state is mounted on the relay roller 482, and the other end is mounted on the feed roller 442 at the rear end of the belt guide 44.

[0148] The guiding mechanism 47 for guiding the upper left belt 41, the upper right belt 42 and the power transmission belt 411 and the power transmission belt 421 comprises: a pair of first tensioning rollers 471 arranged front to back, a pair of second tensioning rollers 472 arranged front to back, a pair of third tensioning rollers 49 arranged front to back, a guide arm 475 including upper and lower connecting rod members 473 and connecting rod member 474, and two guide rollers 476 rotatably arranged on the connecting rod member 473.

[0149] A pair of first tension rollers 471 are arranged in a front-to-rear arrangement below the motor pulley 452. The front and rear first tension rollers 471 each have a rolling body that abuts against the power transmission belt 411 on the left and the power transmission belt 421 on the right from the outside on the same rotation axis along the left-right direction. The pair of first tension rollers 471 press against both the power transmission belt 411 and the power transmission belt 421 from the outside and apply tension toward the inside to them.

[0150] In addition, the first tension roller 471 on the rear side is attached to the motor bracket 451 in a state where the position of the rotation axis can be adjusted in the front-rear direction.

[0151] Thus, the first tension roller 471 on the rear side can adjust the tension of the power transmission belt 411 and the power transmission belt 421 at the same time.

[0152] The pair of second tension rollers 472 are arranged in a front-to-rear arrangement between the motor pulley 452 and the pair of first tension rollers 471 .

[0153] The front and rear second tension rollers 472 are rotatable about axes extending in the left-right direction, and come into pressure contact with only the right power transmission belt 421 from the inside to apply tension toward the outside.

[0154] In addition, the right power transmission belt 421 is extended to the front and rear sides by the pair of second tension rollers 472, so that interference with the motor pulley 452 located in the middle of the path can be avoided.

[0155] Furthermore, the second front and rear tension rollers 472 are attached to the motor bracket 451 in a state where the positions of the rotation axes can be adjusted in the front-rear direction.

[0156] Thus, the second tension roller 472 can adjust the tension of only the power transmission belt 421 .

[0157] That is, the tension of the power transmission belt 411 is appropriately adjusted by the first tension roller 471 , and the tension of the power transmission belt 421 is appropriately adjusted by the first tension roller 471 and the second tension roller 472 .

[0158] The upper end of the upper link member 473 constituting the guide arm 475 is connected to the lower end of the motor bracket 451 in a manner that allows rotation around an axis along the left-right direction. In addition, the lower end of the upper link member 473 is connected to the upper end of the lower link member 474 in a manner that allows rotation around an axis along the left-right direction.

[0159] Furthermore, as described above, the lower end portion of the lower link member 474 is connected to the left and right side surfaces of the pair of extending arm portions 742 of the mounting base 74 so as to be rotatable around an axis extending in the left-right direction.

[0160] At the lower end of the upper link member 473 , two guide rollers 476 arranged in a front-rear arrangement are supported so as to be rotatable around an axis extending in the left-right direction.

[0161] Each of the front and rear guide rollers 476 has a rolling body that abuts against the left power transmission belt 411 and the right power transmission belt 421 on the same rotation axis along the left-right direction.

[0162] The lower end of the lower link member 474 is connected to the mounting platform 74. When the presser foot 71 is lifted to a release height for releasing the sewn object on the needle plate 101 by pressing the motor, the connecting parts of the upper link member 473 and the lower link member 474 are bent in a convex direction forward.

[0163] On the other hand, the front and rear guide rollers 476 contact the left and right power transmission belts 411 and 421 from the inner and outer sides of the ring, respectively, and bend the left and right power transmission belts 411 and 421 at the contact position. Moreover, each guide roller 476 is configured to contact the left and right power transmission belts 411 and 421 from the direction where the inner angle of the guide roller 476 side becomes smaller when the presser foot 71 is lifted to the release height of the sewing material on the needle plate 101 by pressing the motor.

[0164] Thereby, when the presser foot 71 is lifted, the left and right power transmission belts 411 and 421 are prevented from being loosened, thereby suppressing the change of the tension force.

[0165] In addition, when the presser foot 71 rises and falls due to changes in the thickness or unevenness of the sewn material, and the bending angle of the upper connecting rod member 473 and the lower connecting rod member 474 changes, the left and right power transmission belts 411 and 421 can also be prevented from loosening, thereby suppressing changes in the tension force.

[0166] The lower link member 474 includes a pair of long plates of the same shape when viewed from the left and right directions. As described above, the upper end of the lower link member 474 is connected to the lower end of the upper link member 473 in a manner that allows rotation about the left and right directions. In addition, the lower end of the lower link member 474 is connected to the left and right surfaces of the pair of extension arm portions 742 of the mounting platform 74 in a manner that allows rotation about the left and right directions.

[0167] The lower link member 474 supports the relay rollers 481 and 482 arranged in the left and right between the pair of long plates at the middle portion thereof so as to be rotatable on the same axis along the left-right direction.

[0168] The left relay roller 481 is provided to stretch the lower end of the left power transmission belt 411 being stretched, and is provided to stretch the upper end of the left upper belt 41 being stretched. Thus, the relay roller 481 can impart a conveying force from the power transmission belt 411 to the left upper belt 41.

[0169] The right relay roller 482 is provided to stretch the lower end of the right power transmission belt 421 being stretched, and is provided to stretch the upper end of the right upper belt 42 being stretched. Thus, the conveying force can be given from the power transmission belt 421 to the right upper belt 42 through the relay roller 482.

[0170] One of the pair of third tension rollers 49 is supported rotatably around an axis along the left-right direction between the pair of extending arm portions 742 at a connection position of the lower link member 474 of the pair of extending arm portions 742 of the mounting base 74 .

[0171] In addition, the other of the pair of third tension rollers 49 is supported between the extending end portions of the pair of extending arm portions 742 of the mounting base 74 so as to be rotatable about an axis extending in the left-right direction.

[0172] The pair of third tension rollers 49 functions as a conveyor belt tension adjustment mechanism.

[0173] Fig.10 4 is a perspective view showing an enlarged view of the periphery of a pair of third tension rollers 49. Fig.11 This is a side view of one of the third tension rollers 49 as seen from the left.

[0174] Each of the third tension rollers 49 arranged front and rear has a rolling element 491 abutting against the upper left belt 41, a rolling element 492 abutting against the upper right belt 42, and a shaft member 493 as an eccentric shaft that supports the left and right rolling elements 491 and 492 concentrically and rotatably.

[0175] The shaft member 493 has shaft portions 493a at both left and right ends, and the shaft portions 493a penetrate through each of the pair of extension arm portions 742 of the mounting base 74 in the left-right direction and are rotatable relative to the pair of extension arm portions 742. Furthermore, the left and right shaft portions 493a of the shaft member 493 are concentric, and an eccentric support shaft 493b is included between the left shaft portion 493a and the right shaft portion 493a.

[0176] The left and right shaft portions 493a and the eccentric support shaft 493b are both along the left-right direction.

[0177] The eccentric support shaft 493b supports the left and right rolling elements 491 and 492 concentrically and rotatably. Fig.11 As shown by the double-dotted line, by rotating the shaft 493a, the left and right rolling elements 491 and 492 can be moved around the shaft 493a. Thus, each rolling element 491 and 492 can be moved in the direction of contacting with or separating from the upper left belt 41 or the upper right belt 42, so that the tension applied to the upper left belt 41 and the upper right belt 42 can be increased or decreased.

[0178] The pair of extension arms 742 are each formed with a through hole for the shaft 493a to pass through. Furthermore, a threaded hole (not shown) is formed that passes from the outside to the through hole along a radial direction centered on the through hole. A set screw with a hexagonal hole, for example, can be screwed into the threaded hole to fix the shaft 493a.

[0179] In addition, a groove for inserting a negative screwdriver is formed at the head of the shaft portion 493a, which can easily rotate the shaft member 493. In addition, the head of the shaft portion 493a is not limited to a negative screwdriver, and a structure that can be rotated by other tools such as a groove or a hexagonal hole of a positive screwdriver can also be set.

[0180] With these structures, the shaft member 493 can be easily rotated by a tool by loosening the set screw with the hexagonal hole, thereby adjusting the tension applied to the upper left belt 41 and the upper right belt 42. And after adjustment, the adjusted tension can be maintained by tightening the set screw with the hexagonal hole.

[0181] The third tension rollers 49 at the front and rear sides contact the left and right upper belts 41 and 42 from the inner and outer sides of the ring, respectively, and bend the left and right upper belts 41 and 42 at the contact position. Furthermore, the third tension rollers 49 are configured to contact the left and right upper belts 41 and 42 in the direction where the inner angle of the third tension roller 49 side becomes smaller when the presser foot 71 is lifted to the release height of the sewn object on the needle plate 101 by pressing the motor.

[0182] Thereby, when the presser foot 71 is lifted, the left and right upper belts 41 and 42 are prevented from being loosened.

[0183] Furthermore, even when the presser foot 71 is raised or lowered due to a change in thickness or unevenness of the sewn material, the left and right upper belts 41 and 42 are prevented from loosening, thereby suppressing a change in tension.

[0184] [Use of sewing machine] The sewing machine 100 having the above-described structure can perform sewing with upper tape feeding and lower tape feeding.

[0185] In this case, the lower feeding mechanism 20 is fed by Figure 6 The lower belts 21 to 24 are arranged in a certain form, and can be fed and sewn at different speeds on the front and rear sides of the needle hole 13.

[0186] In addition, the lower feeding mechanism 20 is Figure 7 The lower belts 21 to 24 are arranged in a certain form, and can be fed and sewn at different speeds on the left and right sides of the needle hole 13.

[0187] Furthermore, during sewing, the upper feed mechanism 40 conveys the left and right power transmission belts 411 and 421 by driving the upper left motor 45 and the upper right motor 46 .

[0188] The left and right power transmission belts 411 and 421 transmit torque from the motor pulleys 452 and 462 to the relay rollers 481 and 482 .

[0189] Furthermore, the relay rollers 481 and 482 convey the left and right upper belts 41 and 42 .

[0190] As a result, the workpiece on the needle plate 101 abutted by the upper belts 41 and 42 is given a conveying force from above and is fed at a predetermined feed pitch.

[0191] [Technical Effects of Embodiments of the Invention] The sewing machine 100 has a structure in which the upper feeding mechanism 40 applies a conveying force to the left and right upper belts 41 and 42 from the upper left motor 45 and the upper right motor 46 as the driving sources for upper feeding of the sewn material via the power transmission belts 411 and 421 .

[0192] Therefore, when it is necessary to replace any one of the belts 41, 42, 411, and 421, there is no need to remove or reinstall the belt for the entire path of the belt from the upper left motor 45 and the upper right motor 46 to the needle drop position, thereby reducing the burden of replacing the belts 41, 42, 411, and 421 and making it easier to do so.

[0193] In particular, the left and right upper belts 41 and 42 are in direct contact with the sewn material and are arranged outside the cover (not shown) provided in the upper feeding mechanism 40, and are easily deteriorated. Therefore, the replacement frequency of the left and right upper belts 41 and 42 is higher than that of the power transmission belts 411 and 421.

[0194] In addition, the left and right upper belts 41 and 42 may be replaced with upper belts 41 and 42 having different hardness or friction depending on the properties of the material of the sewn object.

[0195] According to these circumstances, the left and right upper belts 41 and 42 which are frequently replaced can be easily replaced, and therefore, it is possible to particularly reduce the workload.

[0196] In addition, by setting the structure of the upper belt 41, the upper belt 42 and the power transmission belt 411, the power transmission belt 421, it is easy to arrange the upper belt 41, the upper belt 42 on the outside of the cover of the upper feed mechanism 40, and the upper belt 41, the upper belt 42 can be easily replaced.

[0197] In addition, it is difficult to ensure space for arranging the upper left motor 45 and the upper right motor 46 in the upper feeding mechanism 40, and the belt path from the motor pulley 452 and the motor pulley 462 to the needle drop position tends to become longer. In contrast, since the belt of the upper feeding mechanism 40 is divided into the power transmission belt 411, the power transmission belt 421 and the left and right upper belts 41 and 42, the burden of replacing the belts 41, 42, 411 and 421 can be effectively reduced and can be carried out very easily.

[0198] In addition, the upper feed mechanism 40 is constructed as follows: an upper belt 41 and an upper belt 42 are respectively provided at multiple locations around the needle drop position, such as the left and right sides, and each upper belt 41 and upper belt 42 has an upper left motor 45, an upper right motor 46 and a power transmission belt 411, a power transmission belt 421 as a power source.

[0199] In the case of such a structure, the belts may be replaced simultaneously on both sides. However, the more belts are replaced, the easier it is to replace each belt one by one, so the workload can be effectively reduced.

[0200] In the upper feeding mechanism 40 , the belt lengths of the left and right upper belts 41 and 42 are set shorter than the left and right power transmission belts 411 and 421 .

[0201] As described above, upper belts 41 and 42 tend to be replaced more frequently than power transmission belts 411 and 421 , but by being shorter than power transmission belts 411 and 421 , they can be replaced more easily.

[0202] In addition, the upper feeding mechanism 40 has a pair of third tension rollers 49 that function as a tension adjustment mechanism for the left and right upper belts 41 and 42. The left and right upper belts 41 and 42 need to have their tension adjusted according to the type of sewn material, but since the tension can be adjusted by the pair of third tension rollers 49, it can be easily adjusted.

[0203] In particular, a pair of third tensioning rollers 49 are constructed to have left and right rolling bodies 491, 492 that abut against the left and right upper belts 41, 42 and an axis component 493 including an eccentric shaft. Therefore, by rotating the operating axis component 493, the tension of the left and right upper belts 41, 42 can be extremely easily adjusted.

[0204] [other] The above describes the various embodiments of the present invention. However, the present invention is not limited to the embodiments. For example, in the embodiments, a constituent element formed integrally by a single member can be replaced by a constituent element divided into a plurality of members and connected or fixed to each other. In addition, a constituent element formed by connecting a plurality of members can also be replaced by a constituent element formed integrally by a single member. In addition, the details shown in the embodiments can be appropriately changed within the scope of the main purpose of the invention.

[0205] For example, when the conveying paths of the belts 21 to 24 of the lower feed mechanism 20 become longer to a certain extent, the belts 21 to 24 may be replaced by conveying belts that come into contact with the sewn material and power transmission belts that transmit power from the motors 25 and 26 to the conveying belts.

[0206] In addition, in the case of the lower feeding mechanism 20, since two motors are provided for four conveyor belts, the number of power transmission belts for transmitting power to the four conveyor belts may be two.

[0207] In addition, the pair of first tension rollers 471 or the pair of second tension rollers 472 of the upper feeding mechanism 40 may also be configured as the same structure as the third tension roller 49. In addition, the first pressing mechanism 33 or the second pressing mechanism 34 of the lower feeding mechanism 20 may also be configured as the same structure as the third tension roller 49.

[0208] In the above-described embodiment, a lockstitch sewing machine is exemplified as the sewing machine. However, the structure separated into the conveyor belt and the power transmission belt may be applied to sewing machines of a type other than the lockstitch sewing machine using a feeding mechanism using a belt.

[0209] In addition, in the sewing machine 100, if Figure 4 As shown in FIG. 1 , the needle hole 13 is provided in the needle hole member 30 that moves up and down relative to the needle plate 101 at the same cycle as the sewing needle 11, but the present invention is not limited thereto. Fig.12 As shown, the needle hole 13 may be formed directly through the needle plate 101 and fixedly arranged without moving up and down.

Claims

1. A sewing machine comprising a feeding device, wherein the feeding device feeds the sewn material by means of a conveyor belt abutting against the sewn material, wherein the sewing machine is characterized in that: A conveying force is applied to the conveyor belt from a motor serving as a driving source for feeding the sewn article via a power transmission belt.

2. The sewing machine according to claim 1, characterized in that: The feeding device makes the conveyor belt come into contact with the sewn object on the needle plate from above.

3. The sewing machine according to claim 1, characterized in that: The conveyor belts are provided to contact the sewn article around the needle drop position. The motor and the power transmission belt are provided for each of the conveyor belts.

4. The sewing machine according to claim 1, characterized in that: The conveyor belt has a shorter belt length than the power transmission belt.

5. The sewing machine according to claim 1, characterized in that: A conveyor belt tension adjustment mechanism is provided.

6. The sewing machine according to claim 5, characterized in that The tension adjustment mechanism includes a rolling element that contacts the conveyor belt and an eccentric shaft around which the rolling element revolves.

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