Sewing machine

Abstract

The present invention addresses the problem of stably feeding an object to be sewed. A sewing machine (100) includes a feeding device (40) that feeds an object to be sewn by means of conveyance belts (41, 42) that come into contact with the object to be sewn, the sewing machine (100) including: belt guides (43, 44) that are swingably supported above a needle plate (101) by a support member (71) and by a fulcrum shaft (431) along a direction orthogonal to a feeding direction; and feed rollers (432, 442) which are provided at the rear ends of the belt guides (43, 44) and which fold back the belt in such a manner that the conveying direction is the front side at the bottom of the belt guides (43, 44), and in the sewing machine (100), a conveying path for conveying the belt (41, 42) is formed in such a manner that the conveying path passes through the upstream side in the conveying direction of the feed rollers (432, 442) and the lower side of the fulcrum shafts (431) of the belt guides (43, 44).

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 tape that contacts and feeds a workpiece on a throat plate from above, a tape guide that conveys the tape on the workpiece on the throat plate is swingably supported by a support member via a shaft along the left-right direction.

[0003] The tape guide swings up and down at the rear end portion with the downstream side in the feeding direction at the front, and presses the tape passing at the rear end portion to apply a conveying force to the sewn material (for example, refer to Patent Document 1).

[0004] The belt guide extends forward and backward, is supported in a swingable manner in the middle of the forward and backward direction, and is provided with a roller for guiding the belt at the rear end. The belt is conveyed in the following path: it is conveyed from the motor side as a driving source toward the rear obliquely downward, passes through the rear end roller of the belt guide from the upper side toward the lower side, moves toward the front at the bottom of the belt guide, and then returns toward the front obliquely upward.

[0005] [Prior art literature]

[0006] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2017-221644 Summary of the invention

[0008] [Problems to be solved by the invention]

[0009] As described above, the tape guide is supported by the support member so as to be swingable, and the tape passing through the rear end portion feeds the sewn material forward.

[0010] However, when the belt-feed sewing machine is used to reverse feed the sewn material, the roller is pulled backward by the belt conveyed in the reverse direction, whereby the rear end of the belt guide floats up, making it impossible to properly reverse feed, which may cause sewing deviation or feeding failure.

[0011] An object of the present invention is to perform appropriate sewing.

[0012] [Technical means to solve the problem]

[0013] The present invention is a sewing machine.

[0014] The sewing machine comprises a feeding device for feeding the sewn article by means of a conveyor belt abutting against the sewn article, and is characterized in that it comprises:

[0015] The tape guide is supported by the support member above the needle plate so as to be swingable by a support shaft extending in a direction perpendicular to the feeding direction; and

[0016] The guide part is provided at the rear end of the belt guide, and the conveyor belt is folded back at the bottom of the belt guide so that the conveying direction becomes the front side, and in the sewing machine,

[0017] A conveyance path of the conveyor belt is formed so as to pass through the belt guide at a position upstream of the guide portion in a conveyance direction and at a position below the support shaft.

[0018] [Effects of the Invention]

[0019] The sewing machine of the present invention can suppress the lifting of the tape guide and perform appropriate sewing by the above-mentioned structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a rear view of the sewing machine which is an embodiment of the invention.

[0021] Figure 2 This is a left side view of a sewing machine.

[0022] Figure 3 It is a three-dimensional diagram of a sewing machine.

[0023] 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.

[0024] Figure 5 It is a three-dimensional view of the guide frame of the lower feed mechanism.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] Fig. 9 This is a left side view of the upper feed mechanism and its surroundings of the needle drop position.

[0029] Fig.10 is from Fig. 9 The left side view of the state after the left belt guide is removed from the structure of the upper feed mechanism.

[0030] Fig.11 This is a perspective view of a shaft member that locks a tension spring.

[0031] Fig.12 This is a left side view of the vicinity of the presser foot in which the shaft member is mounted in a state where the distance between the shaft portion to which both ends of the tension spring are connected and the locking shaft is lengthened.

[0032] Fig.13 This is a left side view of the vicinity of the presser foot in which the shaft member is mounted in a state where the distance between the shaft portion to which both ends of the tension spring are connected and the locking shaft is shortened.

[0033] Fig.14 It is a left side view of the vicinity of a tape guide of a comparative example which does not constitute the characteristic conveyance path of the upper tape of the sewing machine of the present embodiment.

[0034] Fig.15 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.

[0035] [Explanation of Symbols]

[0036] 11: Stitches

[0037] 12: Needle bar

[0038] 13: Pinhole

[0039] 20: Lower feeding mechanism

[0040] 21: Rear lower left belt (conveyor belt)

[0041] 22: Front left lower belt (conveyor belt)

[0042] 23: Front right lower belt (conveyor belt)

[0043] 24: Rear right lower belt (conveyor belt)

[0044] 25: First Motor

[0045] 26: Second Motor

[0046] 40: Upper feeding mechanism (feeding device)

[0047] 41: Upper left belt (conveyor belt)

[0048] 42: Upper right belt (conveyor belt)

[0049] 43, 44: with guide

[0050] 431: Axis

[0051] 432, 442: Feed roller

[0052] 433, 443: Extension spring

[0053] 434, 444: shaft

[0054] 45: Upper left motor

[0055] 46: Upper right motor

[0056] 47: Guidance Agency

[0057] 70: Pressing mechanism

[0058] 71: Presser foot (support member)

[0059] 711: Base plate

[0060] 712: Connection

[0061] 72: Pressure rod

[0062] 74: Installation table

[0063] 741: Fitting recess

[0064] 75, 76: shaft components

[0065] 100: Sewing machine

[0066] 101: Needle plate DETAILED DESCRIPTION

[0067] [Overview of Embodiments of the Invention]

[0068] Hereinafter, the sewing machine 100 as an embodiment of the present invention will be described in detail.

[0069] Figure 1 1 shows a rear view of the sewing machine 100, Figure 2 A left side view showing the sewing machine 100, Figure 3 A perspective view showing the sewing machine 100 is shown.

[0070] The following is the sewing object (refer to Fig.12 ) is set as "front", and the upstream side of the feeding direction is set as "rear". In the forward state, 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.

[0071] 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.

[0072] As the sewing machine 100 as the embodiment of the present invention, a so-called lockstitch sewing machine is exemplified.

[0073] 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.

[0074] The needle vertical movement mechanism imparts a vertical movement action to the sewing needle 11 .

[0075] The lower feeding mechanism 20 applies a feeding action to the workpiece on the needle plate 101 from below.

[0076] The upper feeding mechanism 40 applies a feeding operation to the sewn material on the needle plate 101 from above.

[0077] The cloth pressing mechanism 70 applies a pressing pressure to the sewn material on the needle plate 101 .

[0078] 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.

[0079] 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, but since these are well-known structures, the description thereof is omitted.

[0080] [Sewing machine stand]

[0081] The sewing machine frame 110 supports or accommodates various structures of the sewing machine 100 .

[0082] The sewing machine frame 110 includes a sewing machine base portion 111 , a vertical cylinder portion 112 , and a sewing machine arm portion 113 .

[0083] The sewing machine base 111 is located at the lower portion of the sewing machine 100 and extends in the left-right direction.

[0084] The vertical cylinder portion 112 is provided upright from the right end portion of the sewing machine base portion 111 .

[0085] The sewing machine arm portion 113 extends toward the left from the upper end portion of the vertical cylinder portion 112 .

[0086] [Needle up and down movement mechanism]

[0087] 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.

[0088] The needle vertical movement mechanism includes an upper shaft which is disposed inside the sewing machine arm portion 113 in a state extending along the left-right direction and is rotationally driven by the sewing machine motor.

[0089] Furthermore, if Figure 1 to Figure 4 As shown, the needle up and down movement mechanism includes: a needle bar 12 that holds the sewing needle 11 at the lower end, and a crank mechanism that converts the rotational force of the upper shaft into a reciprocating driving force for up and down movement and transmits it to the needle bar.

[0090] In addition, since the upper shaft and the crank mechanism are well-known components, their illustration is omitted.

[0091] The needle bar 12 extends in the up-down direction and is supported by the lower left end of the sewing machine arm 113 so as to be able to move up and down.

[0092] 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.

[0093] 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 exposed and arranged above. That is, the composite opening 102 is a shape in which a plurality of rectangular openings where the needle hole member 30 and the lower belts 21 to 24 are exposed are integrally composited.

[0094] [Shuttle mechanism]

[0095] 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 .

[0096] The shuttle shaft is rotatably supported 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 from the upper shaft.

[0097] The inner shuttle 14 is accommodated inside the outer shuttle 15. Furthermore, the inner shuttle 14 accommodates a bobbin (not shown) for supplying a lower thread therein.

[0098] 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.

[0099] 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.

[0100] [Lower feed mechanism]

[0101] 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.

[0102] The following is based on Figure 1 to Figure 7 The lower feeding mechanism 20 will be described in detail.

[0103] 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 .

[0104] 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 .

[0105] 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, 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.

[0106] A first pulley 31 is connected to the output shaft of the first motor 25 on the front side via a rotating shaft 27 .

[0107] A second pulley 32 is connected to the output shaft of the second motor 26 on the rear side via the rotating shaft 28 .

[0108] The rotating shafts 27 and 28 are both parallel to the left-right direction and are rotatably supported in the sewing machine base 111 .

[0109] The first pulley 31 and the second pulley 32 are supported rotatably around axes along the left-right direction 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.

[0110] The first pulley 31 and the second pulley 32 are arranged in an overlapping manner when viewed from the front-rear direction, that is, they are 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.

[0111] The first pulley 31 and the second pulley 32 can be laid over all of the lower belts 21 , 22 , 23 , and 24 that are arranged in parallel in the left-right direction.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] Thus, each of the lower belts 21 to 24 can be installed by appropriately selecting the first pulley 31 and the second pulley 32 .

[0116] 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 .

[0117] In addition, the lower belts 21, 22, 23, and 24 are arranged in order from left to right.

[0118] like Figure 2 As shown, the guide frame 29 (guide member) is arranged so as 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.

[0119] 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 the lower belts 21 to 24 .

[0120] 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.

[0121] A fitting groove 297 is formed along the front-rear direction at the left-right center of the upper portion of the outer peripheral surface of the main body 296. A pinhole member 30 having a long plate shape in the front-rear direction is disposed inside the fitting groove 297. The pinhole member 30 has a pinhole 13 penetrating vertically formed at the needle drop position.

[0122] 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.

[0123] 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 are provided on the upper part of the outer peripheral surface of the main body 296 to guide each lower belt 21 to 24.

[0124] 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 .

[0125] 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 forward. 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.

[0126] The first guide portion 291 is located on the left side of the pinhole 13 and its approximate total length is located on the rear side of the center of the pinhole 13 .

[0127] Furthermore, the first guide portion 291 has a flat and horizontal guide surface 291a ( Figure 5 The guide surface 291a is arranged to face the composite opening 102 of the needle plate 101 when viewed from above.

[0128] 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 .

[0129] The guide surface 291 a is formed such that its front end portion is located slightly rearward of the center of the needle hole 13 , and the rear left lower belt 21 abuts against the workpiece further rearward than the center of the needle hole 13 .

[0130] The second guide portion 292 is located on the left side of the needle hole 13 and on the right side of the first guide portion 291 , and its approximate total length is located on the front side of the center of the needle hole 13 .

[0131] Furthermore, 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.

[0132] 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 .

[0133] The guide surface 292 a is formed such 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 sewn object further forward than the center of the needle hole 13 .

[0134] The third guide portion 293 is located on the right side of the pinhole 13 and its approximate total length is located on the front side of the center of the pinhole 13 .

[0135] Furthermore, 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.

[0136] 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 .

[0137] The guide surface 293 a is formed such 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 sewn object further forward than the center of the needle hole 13 .

[0138] The fourth guide portion 294 is located to the right of the pinhole 13 and the third guide portion 293 , and its approximate total length is located to the rear of the center of the pinhole 13 .

[0139] Furthermore, 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 102 of the needle plate 101 when viewed from above.

[0140] 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 .

[0141] The guide surface 294 a is formed such that its front end portion is located slightly rearward of the center of the needle hole 13 , and the rear right lower belt 24 abuts against the sewn object further rearward than the center of the needle hole 13 .

[0142] 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 will not interfere with each other, and the transport force based on the front and rear feed speed difference (transport amount difference) can be applied to the sewn object. 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.

[0143] 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.

[0144] 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 .

[0145] 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 obliquely upward and forward.

[0146] Furthermore, the left and right surfaces of the upper end of the support plate 333 support the left and right pressure rollers 331 and 332 concentrically and rotatably. The support plate 333 is configured so that the left and right pressure rollers 331 and 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.

[0147] 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.

[0148] 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 to move 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.

[0149] 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 and right directions. 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.

[0150] Thus, the left pressure roller 331 can come into contact with either the rear left lower belt 21 or the front left lower belt 22 that is stretched between the guide frame 29 and the first pulley 31 .

[0151] 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 that are stretched between the guide frame 29 and the first pulley 31 .

[0152] 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.

[0153] 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 .

[0154] The support plate 343 has the same structure as the support plate 333 , and is supported on the base block 334 with its length direction facing rearward and obliquely upward.

[0155] The support plate 343 supports the left pressure roller 341 and the right pressure roller 342 on the left and right surfaces of the upper end thereof so as to be concentric and rotatable. 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.

[0156] 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.

[0157] 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.

[0158] Thus, the left pressure roller 341 can come into contact with either the rear left lower belt 21 or the front left lower belt 22 that is stretched between the guide frame 29 and the second pulley 32 .

[0159] Likewise, 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 that are stretched between the guide frame 29 and the second pulley 32 .

[0160] 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.

[0161] Therefore, even when each of the lower belts 21 to 24 is stretched over either the first pulley 31 or the second pulley 32 , tension can be applied by either the first pressurizing mechanism 33 or the second pressurizing mechanism 34 .

[0162] 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.

[0163] 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 .

[0164] When the bolts are loosened to retract the pressure rollers 331 , 332 , 341 , 342 , the lower belts 21 to 24 can be easily removed from the pulleys 31 , 32 and re-installed.

[0165] Therefore, it is easy to select and Figure 6 Sewing and Figure 7 Sewing in the erected state.

[0166] For example, in Figure 6 In the erected state (set to the front and rear differential feeding state), the so-called shrinkage sewing can be performed in which the part closer to the front side of the needle drop position is fed faster than the part closer to the rear side of the needle drop position.

[0167] In addition, in the front-rear differential feeding state, sewing can also be performed by feeding the part closer to the front side than the needle drop position more slowly than the part closer to the rear side of the needle drop position to apply tension to the sewn material.

[0168] exist Figure 7 In the setting state (set to the left and right differential feed state), if the left side is fed quickly, right-bent curve sewing can be performed, and if the right side is fed quickly, left-bent curve sewing can be performed.

[0169] In addition, since the curvature can be changed according to the magnitude of the speed difference (transport amount difference) between the left and right sides, various curved sewing can be performed.

[0170] [Cloth pressing mechanism]

[0171] Figure 8 It is a perspective view of the cloth pressing mechanism 70 which is a pressing mechanism for pressing the sewn object from above on the needle plate 101 .

[0172] 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).

[0173] 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.

[0174] 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 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.

[0175] The pressing motor also provides a lifting motion for switching between a pressing height at which the presser foot 71 presses the sewn object on the needle plate 101 and a release height at which the presser foot 71 moves away upward.

[0176] 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.

[0177] The presser foot 71 is mounted on the lower end of the press rod 72 via a mounting platform 74. The mounting platform 74 is a block whose upper surface and lower surface are horizontal and flat. The mounting platform 74 is formed with an insertion hole that can be inserted into the press rod 72. The mounting platform 74 is fixed to the lower end of the press rod 72 by tightening a screw, for example.

[0178] In addition, a lower end portion of a link member 474 of the upper feed mechanism 40 described later is connected to a front end portion of the mounting table 74 so as to be rotatable around an axis along the left-right direction.

[0179] The presser foot 71 is disposed above the composite opening 102 of the needle plate 101. The presser foot 71 presses the sewn article from above so that the conveying force of each lower belt 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 guide 43 and the belt guide 44 of the upper feed mechanism 40 so that they can be conveyed. That is, the presser foot 71 functions as a supporting member.

[0180] Furthermore, the presser foot 71 has a function of pressing the upper belts 41 and 42 against the sewn material to appropriately transmit the conveying force thereof to the sewn material.

[0181] like Figure 8 As shown, the presser foot 71 includes a bottom plate 711 for pressing a workpiece from above and a connecting portion 712 attached to the lower end of a press rod 72 .

[0182] 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.

[0183] The connecting portion 712 is vertically provided on the upper surface of the front end of the bottom plate 711, and is connected to the bottom plate 711 so as to be slightly swingable 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 by screwing, for example. In addition, the connecting portion 712 may be joined to the mounting platform 74 by welding or the like, or may be formed by integrating the connecting portion 712 and the mounting platform 74 into one member.

[0184] [Upper feed mechanism]

[0185] Fig. 9 It is a left side view of the needle drop position and the surrounding area of ​​the upper feed mechanism 40. Fig.10 is from Fig. 9 A left side view showing the state in which the left belt guide 43 is removed from the structure of the upper feed mechanism 40.

[0186] like Figure 1 , Figure 2 , Figure 8 to Figure 10 As shown, the upper feeding mechanism 40 includes: an upper left belt 41 and an upper right belt 42 serving as conveyor belts, the left and right belt guides 43, a belt guide 44, an upper left motor 45 serving as a driving source for feeding the upper left belt 41, an upper right motor 46 serving as a driving source for feeding the upper right belt 42, and a guiding mechanism 47 for guiding each upper belt 41, 42 from each upper motor 45, 46 to the presser foot 71.

[0187] The left and right tape guides 43 and 44 are mounted on the left and right sides of the presser foot 71 .

[0188] The belt guides 43 and 44 are rotatably mounted on left and right side surfaces of the lower portion of the connecting portion 712 of the presser foot 71 via a support shaft 431 extending in the left-right direction.

[0189] Each of the tape guides 43 and 44 has a shape in which the front end portion extends obliquely upward and forward, the front end portion is closest to the needle plate 101 in front of the rear end portion, and the rear end portion rises obliquely upward and backward when viewed from the side.

[0190] The left and right belt guides 43 and 44 have shapes that are symmetrical with each other on the basis of a plane along the front-back and top-bottom directions.

[0191] like Fig.10 As shown, the left and right tape guides 43 and 44 include feed rollers 432 and 442 as guides that are rotatable about axes extending in the left-right direction at rear ends thereof.

[0192] The left and right endless ring-shaped upper belts 41 and 42 are conveyed from the front oblique upper side of the belt guides 43 and 44 toward the rear oblique lower side, and are guided 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 respectively folded downward along the outer circumference from the upper part of the feed rollers 432 and 442 and guided to move forward toward the portion of each belt guide 43 and 44 closest to the needle plate 101, and then return to the front oblique upper direction. When each upper belt 41 and 42 moves forward along the portion 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.

[0193] The structure forming the conveyance path of the left and right tape guides 43 and 44 and the peripheries thereof and the left and right upper tapes 41 and 42 will be described in detail.

[0194] like Fig.10 As shown, on the left side surface of the right belt guide 44 (the surface on the presser foot 71 side), slightly in front of and slightly lower than the feed roller 442, a first guide piece 445 is erected toward the left and is in sliding contact with the upper right belt 42 conveyed upstream of the feed roller 442 from above.

[0195] In addition, in this specification, when the conveyance of each belt 21 to 24, 41, and 42 is referred to as "upstream" or "downstream", especially when there is no special explanation, "upstream" or "downstream" during forward feeding (forward feeding of the sewn material) is indicated.

[0196] In addition, a second guide piece 446 is erected to the left below the first guide piece 445 and is in sliding contact with the upper right belt 42 conveyed downstream of the feed roller 442. The second guide piece 446 is arranged at the lowest position in the rear portion of the right belt guide 44, and when the upper right belt 42 passes below the second guide piece 446, it contacts the sewn material on the needle plate 101 and is fed.

[0197] As described above, since the left and right belt guides 43 and 44 have a symmetrical shape, a first guide piece (not shown in the figure) is erected toward the right on the right side surface (the surface on the presser foot 71 side) of the left belt guide 43, and the first guide piece (not shown in the figure) is vertically arranged toward the right, and slides from the top with the upper left belt 41 conveyed more upstream than the feed roller 432, and a second guide piece (not shown in the figure) is slidingly arranged from the top with the upper left belt 41 conveyed more downstream than the feed roller 432.

[0198] Furthermore, if Fig.10 As shown, on the left side surface (the surface with the guide 43 side) of the lower part of the connecting portion 712 of the presser foot 71, there is formed a guide protrusion 713 which protrudes cylindrically toward the left around the insertion hole of the support shaft 431, and on the front side thereof, there is provided a rolling body 714 which is supported and can rotate around an axis along the left-right direction.

[0199] The lower portion of the outer peripheral surface of the guide protrusion 713 comes into sliding contact from above with the upper left belt 41 conveyed upstream of the feed roller 432 and the first guide piece.

[0200] Furthermore, the lower portion of the outer peripheral surface of the rolling element 714 abuts against the upper left belt 41 conveyed downstream of the feed roller 432 and the second guide piece from above.

[0201] The lower portion of the connecting portion 712 of the presser foot 71 has a shape that is bilaterally symmetrical with respect to a plane extending along the front, rear, top and bottom directions.

[0202] Therefore, on the right side surface (the surface with the guide 44 side) of the lower part of the connecting portion 712 of the presser foot 71, a guide protrusion (not shown) is formed which protrudes cylindrically toward the right around the insertion hole of the support shaft 431, and a rolling body (not shown) is provided on the front side thereof so as to be supported so as to rotate around an axis along the left-right direction.

[0203] The lower portion of the outer peripheral surface of the guide protrusion slides from above against the upper right belt 42 conveyed upstream of the feed roller 442 and the first guide piece 445 .

[0204] Furthermore, the lower portion of the outer peripheral surface of the rolling element abuts from above against the upper right belt 42 conveyed downstream of the feed roller 442 and the second guide piece 446 .

[0205] In addition, it is also possible to configure a roller that rotates around the axis in the left-right direction around the support shaft 431 instead of the guide protrusions provided on the left and right side surfaces of the lower part of the connecting portion 712. That is, it is sufficient to provide a structure in which the left and right upper belts 41 and 42 can be guided in a manner that they pass through the lower side of the support shaft 431 at the upstream side of the feed roller 432 and the feed roller 442, respectively. Therefore, it is also possible to use a structure like the guide pieces 445 and 446.

[0206] In addition, the guide protrusion 713 may be provided on the right side surface of the tape guide 43 so as to protrude rightward. The same is true for the tape guide 44.

[0207] In addition, the rolling element 714 may be rotatably provided on the right side of the tape guide 43. The same applies to the tape guide 44.

[0208] 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.

[0209] 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.

[0210] As described above, each of the tape guides 43 and 44 is axially supported by the lower portion of the connection portion 712 of the presser foot 71 via the support shaft 431. One ends of the tension springs 433 and 443 as springs are connected to the shaft portions 434 and 444 provided at the front end portions of each of the tape guides 43 and 44. The other ends of each of the tension springs 433 and 443 are connected to the shaft members 75 and 76 respectively mounted on the left and right side portions of the mounting base 74, so that tension is applied upward to the front end portions of each of the tape guides 43 and 44.

[0211] Therefore, the rear end side of each tape guide 43, 44 is rotated downward, and a pressing force is applied to each upper tape 41, 42 that moves forward along the portion closest to the needle plate 101 toward the needle plate 101. Therefore, a pressing force is applied to each upper tape 41, 42 toward the sewn object on the needle plate 101.

[0212] Fig.11: is a three-dimensional view of the shaft member 75, the shaft member 76. The shaft member 75, the shaft member 76 comprises: a main body 751, the main body 761 which is a long plate in a predetermined direction; a locking shaft 752, the locking shaft 762 of the tension spring 433, the tension spring 443 which is vertically arranged on one plane of the main body 751, the main body 761; and a mounting shaft 753, the mounting shaft 763 for the mounting table 74 which is vertically arranged on the other plane of the main body 751, the main body 761.

[0213] The main body 751 and the main body 761 are elliptical, and a locking shaft 752 and a locking shaft 762 are provided on one plane of one end in the length direction thereof. In addition, a mounting shaft 753 and a mounting shaft 763 are provided on another plane of the other end in the length direction of the main body 751 and the main body 761.

[0214] Through the above structure, the locking shaft 752, the locking shaft 762 and the installation shaft 753, the installation shaft 763 clamp the main body 751, the main body 761 and protrude in opposite directions and are parallel to each other, and the center lines of each other are eccentric in the length direction of the main body 751, the main body 761.

[0215] On the other hand, at the rear end portions of the left and right side surfaces of the mounting platform 74, mounting holes (not shown) are formed extending along the left and right directions, and around the mounting holes on the left and right side surfaces of the mounting platform 74, groove-shaped mating recesses 741 are formed along the rear oblique upward direction.

[0216] The shaft members 75 and 76 can be mounted on the rear end portions of the left and right side surfaces of the mounting base 74 in two different forms.

[0217] Fig.12 and Fig.13 The figure shows a state in which the mounting shaft 753 of the shaft member 75 is inserted into the mounting hole at the rear end portion of the left side surface of the mounting base 74 , and the main body 751 is fitted into the fitting recess 741 .

[0218] Fig.12 The main body 751 is shown in a state where the locking shaft 752 is oriented upward relative to the mounting shaft 753 of the shaft member 75 and the main body 751 is fitted into the fitting recess 741. Fig.13 The figure shows a state where the main body 751 is fitted into the fitting recess 741 with the locking shaft 752 facing downward relative to the mounting shaft 753 .

[0219] Know that in Fig.12 In the embodiment, the distance between the shaft 434 connected to the two ends of the tension spring 433 (not shown) and the locking shaft 752 becomes longer. Fig.13 The interaxial distance between the middle axis portion 434 and the locking axis 752 is shortened.

[0220] In this way, the shaft members 75, 76 and the mounting base 74 can be installed so that the lengths of the left and right tension springs 433, 443 can be replaced in two stages, and have the function of adjusting the tension of the tension springs 433, 443.

[0221] In addition, on the surfaces of the main body 751 and the main body 761 of the shaft member 75 and the shaft member 76 on the side of the locking shaft 752 and the locking shaft 762, there are operating grooves 751a and 761a for inserting the top end of a tool such as a screwdriver to allow the shaft member 75 and the shaft member 76 to rotate around the installation shaft 753 and the installation shaft 763.

[0222] In addition, screw holes penetrating to the left and right mounting holes are formed on the front surface or upper surface side of the mounting base 74, and set screws such as fixing screws with hexagonal holes are screwed in to prevent the mounting shafts 753 and 763 from accidentally falling off.

[0223] The upper motors 45 and 46 on the left and right use motors whose rotation speed can be controlled, such as DC motors, AC motors, stepping motors, etc. Each motor 45 and 46 may also be provided with an encoder.

[0224] Moreover, if Figure 2 As shown, 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.

[0225] 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.

[0226] Furthermore, a motor pulley 452 is attached to the output shaft of the upper left motor 45 , and one end of the upper left belt 41 is wound around the motor pulley 452 .

[0227] Furthermore, a motor pulley 462 is attached to the output shaft of the upper right motor 46 , and one end of the upper right belt 42 is wound around the motor pulley 462 .

[0228] The upper left belt 41 is in an endless loop, and one end of the belt is stretched over the motor pulley 452 of the upper left motor 45 , while the other end is stretched over the feed roller 432 of the belt guide 43 .

[0229] The upper right belt 42 is also endless, and one end of the belt is stretched on the motor pulley 462 of the upper right motor 46 , and the other end is stretched on the feed roller 442 at the rear end of the belt guide 44 .

[0230] Furthermore, when viewed from the left and right directions, the path from the motor pulley 452 of the upper left belt 41 to the feed roller 432 and the path from the motor pulley 462 of the upper right belt 42 to the feed roller 442 are repeated except for the peripheries of the motor pulley 452 and the motor pulley 462. In addition, the upper right belt 42 is arranged on the right side relative to the upper left belt 41.

[0231] The guide mechanism 47 guides the upper left belt 41 and the upper right belt 42 along the respective paths.

[0232] The guiding mechanism 47 comprises: a pair of first tensioning rollers 471 arranged on the left and right, a pair of second tensioning rollers 472 arranged on the left and right, a guiding arm 475 including upper and lower link members 473 and 474, and a plurality of guiding rollers 476 rotatably arranged at respective parts on the paths of the upper belts 41 and 42.

[0233] The pair of first tension rollers 471 is disposed below the motor pulley 452. In addition, the pair of second tension rollers 472 is disposed between the motor pulley 452 and the pair of first tension rollers 471.

[0234] The pair of first tension rollers 471 is rotatable about an axis along the left-right direction and has a wide axial width. The pair of first tension rollers 471 is pressed against both the left upper belt 41 and the right upper belt 42 from the outside and applies tension to the inside.

[0235] The pair of second tension rollers 472 can rotate around an axis along the left-right direction and has a narrow axial width. The pair of second tension rollers 472 is pressed against only the right upper belt 42 from the inside and applies tension to the belt toward the outside.

[0236] In addition, the upper right belt 42 is expanded 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.

[0237] One end of the upper link member 473 constituting the guide arm 475 is rotatably connected to the lower end of the motor bracket 451 about an axis along the left-right direction. In addition, the other end of the upper link member 473 is rotatably connected to one end of the lower link member 474 about an axis along the left-right direction.

[0238] Furthermore, as described above, the other end of the lower link member 474 is connected to the front end of the mounting base 74 so as to be rotatable around an axis along the left-right direction.

[0239] At the connection portion between the upper link member 473 and the lower link member 474, there are provided a guide roller 476 that abuts against the inner side of the ring from the front side relative to the upper left belt 41 and the upper right belt 42, and a guide roller (not shown) that abuts against the outer side of the ring from the front side.

[0240] Thus, the left and right upper belts 41 and 42 are conveyed through a path along the upper link member 473 and a path along the lower link member 474 .

[0241] Therefore, even if the presser foot 71 rises and falls due to the change in thickness or unevenness of the sewn material, and the bending angles of the upper link member 473 and the lower link member 474 change, the left and right upper belts 41 and 42 maintain the path along the upper link member 473 and the path along the lower link member 474. Therefore, the path length of each upper belt 41 and 42 is maintained constant, and the change of tension can be suppressed.

[0242] [Retreat Agency]

[0243] Figure 8 to Figure 10 The symbol 60 shown is a retraction mechanism for maintaining the right-side belt guide 44 in the retraction position when using a positioning ruler (not shown in the figure), and the positioning ruler is used to maintain a certain width (edge ​​width) from the side end (for example, the right side end) of the sewn object to perform edge sewing with a dropped needle.

[0244] The positioning ruler has a touch plate for making the right end of the sewn object touch the left side during sewing. The positioning ruler supports the touch plate, which is at a position with a pre-adjusted edge width relative to the needle drop position and is arranged on the right side of the needle drop position, so as to be switchable between a non-use position retreating upward and a use position close to the needle plate.

[0245] The touch plate is arranged close to the needle drop position when the edge width after adjustment is small. In the case described, since the rear end of the belt guide 44 on the right side may interfere with the touch plate, the belt guide 44 is rotated around the support shaft 431, and the rear end is retreated upward.

[0246] The retraction mechanism 60 is a mechanism for maintaining the rear end portion of the tape guide 44 in a state of being retracted upward.

[0247] The retracting mechanism 60 has a holding member 61 whose upper end is axially supported by a support shaft 62 extending in the left-right direction. The holding member 61 rotates so that a recess formed at its lower end engages and holds the shaft 444 of the front end side that moves downward when the rear end of the belt guide 44 is retracted upward.

[0248] Thereby, the holding member 61 of the retracting mechanism 60 can hold the rear end portion of the tape guide 44 in a state of being retracted upward.

[0249] Reference numeral 63 denotes a torsion coil spring which applies force in a direction to rotate the lower end of the retaining member 61 forward, and when the belt guide 44 is not retained, the lower end of the retaining member 61 is retracted rearward without interfering with the belt guide 44 .

[0250] [Use of sewing machine]

[0251] The sewing machine 100 having the above-described structure can perform sewing with upper tape feeding and lower tape feeding.

[0252] In the case described, the lower feeding mechanism 20 is 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.

[0253] 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.

[0254] Next, based on Fig. 9 , Fig.10 and Fig.14 The behavior of the left and right belt guides 43 and 44 when the upper feeding mechanism 40 performs forward feeding (feeding the sewn material forward) and reverse feeding (feeding the sewn material backward) will be described.

[0255] Fig.14 This is a left side view of the belt guide 43 and its surroundings of a comparative example which does not constitute the conveying path of the upper belt which is characteristic of the sewing machine 100 of the present embodiment. In the structure of the comparative example, the guide protrusion 713 and the rolling element 714 are not included. Therefore, the conveying path is constituted so that the upper belts 41 and 42 on the left and right sides conveyed upstream of the feed rollers 432, 442 and the first guide piece pass through the upper side of the shaft portion of the support shaft 431.

[0256] When being fed forward, the left and right upper belts 41 and 42 are conveyed along a conveyance path in which they descend obliquely downward and rearward from the left and right upper motors 45 and 46 and reach the left and right belt guides 43 and 44 .

[0257] Moreover, when the rotation direction of the left and right upper motors 45 and 46 is switched from forward feeding to reverse feeding, the left and right upper belts 41 and 42 act on the rear ends of the left and right belt guides 43 and 44 via the feed rollers 432, 442, the first guide piece and the second guide piece to lift them upward, thereby causing levitation.

[0258] Therefore, the left and right tape guides 43 and 44 cannot appropriately reverse feed the sewn article, and the sewn article may not be fed at a target value, causing feeding failure, fabric deviation, and the like.

[0259] On the other hand, in the sewing machine 100 of the present embodiment, Fig. 9 and Fig.10 As shown, the left and right upper belts 41 and 42 are transported according to the following transport path when feeding in the forward direction: they descend from the left and right upper motors 45 and 46 to the rear and downward direction via the guide mechanism 47, pass under the guide protrusion 713 (the shaft portion of the support shaft 431), and pass under the first guide piece 445, bypass the rear portion of the left and right feed rollers 432 and 442 from top to bottom, and then pass under the second guide piece 446, pass under the rolling body 714, and return to the left and right upper motors 45 and 46 to the front and upward direction via the guide mechanism 47.

[0260] In the above case, the left and right upper belts 41 and 42 pass under the support shaft 431. Therefore, even if the rotation direction of the left and right upper motors 45 and 46 is switched from forward feeding to reverse feeding, the force applied to the feed rollers 432 and 442, the first guide piece, and the second guide piece from the left and right upper belts 41 and 42 acts in a direction that causes the rear ends of the left and right belt guides 43 and 44 to face downward, with the support shaft 431 as the center.

[0261] Therefore, the left and right upper tapes 41 and 42 are pressed toward the workpiece at the rear ends of the left and right tape guides 43 and 44, and the feeding operation can be stably performed at the target feeding amount even in the case of reverse feeding.

[0262] In addition, even when switching from reverse feeding to forward feeding, the left and right upper belts 41 and 42 are pressed to the side of the sewn object at the rear ends of the left and right belt guides 43 and 44, and the feeding action can be stably performed at the target feed amount.

[0263] [Technical Effects of Embodiments of the Invention]

[0264] In the sewing machine 100 , the conveying paths of the left and right upper belts 41 and 42 are formed so as to pass through the lower side of the support shaft 431 of the belt guide 43 and the belt guide 44 at the upstream side of the feed rollers 432 and 442 in the conveying direction.

[0265] Therefore, when the upper feeding mechanism 40 is switched from forward feeding to reverse feeding, the rotational force acting on each of the belt guides 43 and 44 by the tension of the left and right upper belts 41 and 42 is in a direction that causes the rear end portions of the belt guides 43 and 44 to rotate downward via the support shaft 431. Therefore, it is possible to suppress the rear end portions of the belt guides 43 and 44 being fed from floating up from the sewn material, and to perform stable feeding at a target feed amount.

[0266] Therefore, it is possible to provide a sewing machine that maintains high sewing quality and has high reliability.

[0267] In addition, the sewing machine 100 includes a tension spring 433 and a tension spring 443 for pressing the rear end side of the tape guide 43 and the tape guide 44 against the needle plate 101. Therefore, the rear end of the tape guide 43 and the tape guide 44 can be stably suppressed from floating up from the sewn object regardless of the forward feed or the reverse feed. Furthermore, when switching between the forward feed and the reverse feed, the influence on the behavior of the rear end of the tape guide 43 and the tape guide 44 can also be suppressed.

[0268] Therefore, it is possible to provide a sewing machine that maintains higher sewing quality and has high reliability.

[0269] In the sewing machine 100 , the shaft members 75 and 76 , which are connecting portions of the tension springs 433 and 443 on the presser foot 71 side, have a function of adjusting the tension of the tension springs 433 and 443 .

[0270] Therefore, the pressing force of the left and right upper belts 41 and 42 of the left and right belt guides 43 and 44 on the workpiece can be increased or decreased as needed, so that appropriate feeding according to the workpiece can be achieved.

[0271] [other]

[0272] The above describes various embodiments of the present invention. However, the present invention is not limited to the embodiments. For example, in the embodiments, a structural component formed integrally by a single member can be replaced by a structural component divided into a plurality of members and connected or fixed to each other. In addition, a structural component formed by connecting a plurality of members can also be replaced by a structural component 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.

[0273] For example, the tape guides 43 and 44 of the upper feed mechanism 40 are supported by the presser foot 71 , but the present invention is not limited thereto. Other members that support the tape guides 43 and 44 while maintaining a certain height from the needle plate 101 may be used.

[0274] In addition, as the guide part, the feed roller 432 and the feed roller 442 are illustrated, but it is not limited to this. For example, a structure that guides the left and right upper belts 41 and 42 without rolling but sliding along the outer peripheral surface may be adopted.

[0275] In the above-described embodiment, a lockstitch sewing machine is exemplified as the sewing machine. However, the structure separated into a conveyor belt and a power transmission belt may be applied to sewing machines other than the lockstitch sewing machine using a belt-based feeding mechanism.

[0276] 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 to this. Fig.15 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 for feeding a workpiece by means of a conveyor belt abutting against the workpiece, the sewing machine comprising: The tape guide is supported by the support member above the needle plate so as to be swingable by a support shaft extending in a direction perpendicular to the feeding direction; and The guide part is provided at the rear end of the belt guide, and the conveyor belt is folded back at the bottom of the belt guide so that the conveying direction becomes the front side, and in the sewing machine, A conveyance path of the conveyor belt is formed so as to pass through the belt guide at a position upstream of the guide portion in a conveyance direction and at a position below the support shaft.

2. The sewing machine according to claim 1, characterized in that: The guide portion is a rollable feed roller.

3. The sewing machine according to claim 1, characterized in that include: The rear end portion of the tape guide is brought into pressure contact with the spring on the needle plate side.

4. The sewing machine according to claim 3, characterized in that: The spring is a tension spring, one end of which is connected to the belt guide, and the other end of which is connected to the support member. The connecting portion on the other end side of the tension spring has a function of adjusting the tension of the tension spring.

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