Sewing machine

Abstract

To dispose a positioning ruler near a needle location.SOLUTION: A sewing machine comprises: an upper feeding mechanism 40 to feed a sewn article by conveyor belts 41, 42 from above a needle plate 101; and a positioning ruler 50 to position a side end part of the sewn article C with respect to a direction intersecting with a feeding direction of the sewn article C. The upper feeding mechanism 40 has the conveyor belts 41, 42 and belt guides 43, 44 individually on both sides of a needle location 13, and also has a retreating mechanism 60 to hold the conveyor belt 42 and the belt guide 44 on the positioning ruler 50 side with respect to at least the needle location 13 at a retreat position spaced away from the needle location 13.SELECTED DRAWING: Figure 12

Description

[Technical field]

[0001] The present invention relates to a sewing machine that uses a belt feed. [Background technology]

[0002] There is a sewing machine that is equipped with an upper feed mechanism that feeds the workpiece by contacting a belt with the workpiece from above the needle plate, and feeds the workpiece on the lower side and the workpiece on the upper side (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-221644 A Summary of the Invention [Problem to be solved by the invention]

[0004] Sewing machines equipped with a belt-type upper feed mechanism may use a positioning ruler to position the side edge of the workpiece in a direction perpendicular to the feed direction in order to maintain a constant distance from the side edge of the workpiece while sewing. In conventional sewing machines, a presser foot having a belt roller is arranged around the needle drop position, so that a positioning ruler cannot be arranged close to the needle drop position.

[0005] An object of the present invention is to place a positioning ruler close to the needle drop position. [Means for solving the problem]

[0006] The present invention relates to a sewing machine, an upper feed mechanism that feeds the workpiece from above the needle plate using a conveyor belt; a positioning ruler for positioning a side edge of the workpiece in a direction intersecting a feed direction of the workpiece; Equipped with the upper feed mechanism has the conveyor belt and the belt guide on each side of the needle drop position, The sewing machine is characterized in that it has a retraction mechanism that holds at least the conveyor belt and the belt guide on the side of the positioning ruler relative to the needle drop position at a retracted position separated from the needle drop position. Effect of the Invention

[0007] With the above-described configuration, the sewing machine of the present invention makes it possible to dispose the positioning ruler near the needle drop position. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a rear view of the sewing machine according to the embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. 2 is a perspective view showing the top surface of the left end portion of the bed of the sewing machine with the presser foot not shown. [Diagram 5] FIG. 4 is a perspective view of a guide frame of the lower feed mechanism. [Figure 6] FIG. 2 is a perspective view of a feed mechanism in which four conveyor belts are in a front-rear differential feed state. [Figure 7] 1 is a perspective view of a feed mechanism in which four conveyor belts are in a left-right differential feed state; [Figure 8] 4 is a perspective view of the vicinity of a cloth presser mechanism that presses a sewing material from above on the needle plate. FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. 2 is a perspective view of the positioning ruler and its surrounding structure in a non-use position. [Figure 12] FIG. 2 is a perspective view of the positioning ruler and its surrounding structure in a use position. [Figure 13] FIG. [Figure 14] FIG. [Figure 15] FIG. 11 is a perspective view of the periphery of a holding member in a released position in the second embodiment. [Figure 16] 13 is a right side view of the periphery of the holding member in the released position. FIG. [Figure 17] FIG. 4 is a perspective view of the periphery of the holding member in the holding position. [Figure 18] 13 is a right side view of the periphery of the holding member in the holding position. FIG. [Figure 19] FIG. [Figure 20] FIG. [Figure 21] FIG. [Figure 22] FIG. 13 is a right side view showing the configuration around the retraction mechanism in the third embodiment. [Figure 23] FIG. 13 is a right side view showing the configuration around the retraction mechanism in the fourth embodiment. [Figure 24] FIG. 13 is a right side view of the belt guide of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [First embodiment] A sewing machine 100 according to a first embodiment of the present invention will be described in detail below. FIG. 1 is a rear view of the sewing machine 100, FIG. 2 is a left side view of the sewing machine 100, and FIG. Hereinafter, the downstream side in the feed direction of the sewing workpiece C (see FIG. 12) will be referred to as the "front", the upstream side in the feed direction will be referred to as the "rear", the left hand side when facing forward will be referred to as the "left", the right hand side will be referred to as the "right", the vertically upward will be referred to as the "upper", and the vertically downward will be referred to as the "lower". The front-to-rear direction, the left-to-right direction, and the up-to-down direction are perpendicular to each other. In the following description, it is assumed that the sewing machine 100 is placed on a horizontal surface, and the front-to-back and left-to-right directions are horizontal.

[0010] As an example of a sewing machine 100 according to an embodiment of the present invention, a so-called lock stitch sewing machine is shown. The sewing machine 100 includes a sewing machine frame 110, a needle up-down movement mechanism, a lower feed mechanism 20, an upper feed mechanism 40, a presser mechanism 70 as a presser mechanism, a shuttle mechanism, a positioning ruler 50 (see FIG. 11), and a retraction mechanism 60 (see FIG. 11). The needle up-down movement mechanism imparts an up-down movement to the sewing needle 11 . The bottom feed mechanism 20 applies a feed operation to the workpiece C on the needle plate 101 from below. The upper feed mechanism 40 applies a feed operation to the workpiece C on the needle plate 101 from above. The cloth presser mechanism 70 applies a presser pressure to the workpiece C on the needle plate 101 . The shuttle mechanism captures the loop of upper thread from the sewing needle 11 and entangles the bobbin thread to form a stitch. The sewing machine 100 is equipped with various components such as a thread take-up mechanism and thread tensioner that are equipped in a typical lock stitch sewing machine, but as these are well known, a description thereof will be omitted.

[0011] [Sewing machine frame] The sewing machine frame 110 supports or houses each component of the sewing machine 100 described above. The sewing machine frame 110 has a sewing machine bed portion 111 , a vertical body portion 112 , and a sewing machine arm portion 113 . The sewing machine bed portion 111 is located at the bottom of the sewing machine 100 and extends in the left-right direction. The upright body portion 112 stands upright from the right end portion of the sewing machine bed portion 111 . The sewing machine arm portion 113 extends leftward from the upper end portion of the upright body portion 112 .

[0012] [Needle vertical movement mechanism] FIG. 4 is a perspective view showing the upper surface of the left end portion of the sewing machine bed portion 111, with the presser foot, which will be described later, omitted. As shown in Figs. 1 to 4, the needle up-down movement mechanism is disposed inside the sewing machine arm portion 113, is rotationally driven by the sewing machine motor, and has an upper shaft along the left-right direction. The needle up-down movement mechanism further comprises a needle bar 12 which holds the sewing needle 11 at its lower end, and a crank mechanism which converts the rotational force of the upper shaft into a reciprocating driving force for up-down movement and transmits it to the needle bar. The upper shaft and crank mechanism are not shown in the figure because they are well known.

[0013] Needle bar 12 extends in the vertical direction and is supported at the lower left end of sewing machine arm portion 113 so as to be movable up and down. Sewing needle 11 is held at the lower end of needle bar 12 and moves up and down together with needle bar 12. A needle plate 101 made of a horizontal flat plate is provided below needle bar 12 on the upper surface of sewing machine bed portion 111.

[0014] 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, a pinhole member 30 having a pinhole 13 and a rear left lower belt 21, a front left lower belt 22, a front right lower belt 23 and a rear right lower belt 24 of a lower feed mechanism 20 described later are arranged so as to be exposed upward. In other words, the composite opening 102 has a shape in which a plurality of rectangular openings through which the pinhole member 30 and the lower belts 21 to 24 are exposed are integrally combined.

[0015] [Kettle mechanism] The shuttle mechanism has an outer shuttle 14 and an inner shuttle 15 provided below the needle hole member 30 of the needle plate 101, and a shuttle shaft (not shown) that rotates the inner shuttle 15, as shown in FIGS. The shuttle shaft is supported rotatably along the left-right direction within the sewing machine bed portion 111. Rotation about an axis along the left-right direction, which is accelerated twice as fast as that of the upper shaft, is input to the shuttle shaft from the above-mentioned upper shaft via a gear mechanism or a belt mechanism.

[0016] The inner hook 15 is housed inside the outer hook 14. Furthermore, the inner hook 15 houses therein a bobbin (not shown) for supplying a lower thread. The outer hook 14 is connected to the left end of the hook shaft and rotates around the inner hook 15. The inner hook 15 is restricted from rotating together with the outer hook 14. The outer hook 14 has a point on its outer periphery for capturing the loop of the upper thread from the sewing needle 11. By rotating, the outer hook 14 can capture the loop of the upper thread with the point and pass the bobbin thread that is being paid out from inside the inner hook 15 through it. The outer hook 14 and the inner hook 15 are arranged in a housed state inside a substantially cylindrical guide frame 29 of the lower feed mechanism 20, which will be described later.

[0017] [Downfeed mechanism] Fig. 5 is a perspective view of a guide frame 29 of the lower feed mechanism 20, and Figs. 6 and 7 are perspective views of the lower feed mechanism 20. Figs. 6 and 7 show different cases in which lower belts 21 to 24, which will be described later, are hung in different states. The lower feed mechanism 20 will be described in detail below with reference to FIGS.

[0018] The lower feed mechanism 20 includes lower belts 21 to 24 as conveyor belts, a first motor 25, a second motor 26, rotating shafts 27 and 28, a first pulley 31, and a second pulley 32, as shown in the respective drawings. Furthermore, the lower feed mechanism 20 includes a guide frame 29 that guides the lower belts 21 to 24 so that they come into contact with the lower surface of the workpiece C, a first pressure mechanism 33, and a second pressure mechanism .

[0019] The first and second motors 25 and 26 are both motors whose operation amount can be arbitrarily controlled, such as a stepping motor or a servo motor. The first and second motors 25 and 26 are arranged in a line up in front and rear, inside the right end portion of the sewing machine bed portion 111, and have their output shafts facing leftward. A first pulley 31 is connected to the output shaft of the first motor 25 on the front side via a rotating shaft 27 . A second pulley 32 is connected to the output shaft of the second motor 26 on the rear side via a rotating shaft 28 .

[0020] The rotary shafts 27 and 28 are both parallel to each other in the left-right direction and are rotatably supported within the sewing machine bed portion 111. The first and second pulleys 31, 32 are supported rotatably around axes extending in the left-right direction within the left end portion of the sewing machine bed portion 111. Rotational motions are imparted to the first and second pulleys 31, 32 by the first motor 25 and the second motor 26 via the rotary shafts 27, 28, respectively. The first and second pulleys 31, 32 are arranged to overlap each other when viewed from the front-rear direction, i.e., they are at the same height and in the same position in the left-right direction.

[0021] The first and second pulleys 31, 32 are each capable of looping over all of the lower belts 21, 22, 23, 24 that are arranged in parallel in the left-right direction. That is, the first pulley 31 has, on its outer circumferential surface, a left groove 311 for passing the rear left lower belt 21 and the front left lower belt 22 therethrough and a right groove 312 for passing the front right lower belt 23 and the rear right lower belt 24 therethrough. The second pulley 32 has, on its outer circumferential surface, a left groove 321 for passing the rear left lower belt 21 and the front left lower belt 22 therethrough, and a right groove 322 for passing the front right lower belt 23 and the rear right lower belt 24 therethrough. The lower belts 21 to 24 have the same width, and the left and right grooves 311, 312, 321, 322 each have a width of at least two belts. As a result, each of the lower belts 21 to 24 can be stretched over the first pulley 31 and the second pulley 32 by appropriately selecting them.

[0022] Each of the lower belts 21 , 22 , 23 , 24 is an endless loop, and is stretched between the guide frame 29 and the first pulley 31 or between the guide frame 29 and the second pulley 32 . The lower belts 21, 22, 23, and 24 are arranged in parallel in order from left to right.

[0023] 2, the guide frame 29 (guide member) is disposed so as to substantially coincide with the pulleys 31, 32 in the left-right direction and to be between the pulleys 31, 32 in the front-rear direction. Furthermore, the guide frame 29 is disposed above the pulleys 31, 32 and immediately below the needle plate 101. As shown in FIG. 5, the guide frame 29 has a bracket portion 295 for fixing it to the inside of the sewing machine bed portion 111, and a cylindrical main body portion 296 for guiding each of the lower belts 21-24.

[0024] The guide frame 29 is disposed directly below the needle plate 101 with the central axis of the main body 296 oriented in the left-right direction. A fitting groove 297 is formed along the front-rear direction in the left-right center of the upper outer circumferential surface of the main body 296. A plate-shaped pinhole member 30 that is long in the front-rear direction is disposed inside the fitting groove 297. The pinhole member 30 has a pinhole 13 that penetrates vertically at the needle drop position. The needle hole member 30 is connected to a needle up-down movement mechanism (not shown) which uses the above-mentioned sewing machine motor as a drive source to move it up and down at the same cycle as the sewing needle 11. This needle up-down movement mechanism moves the needle hole member 30 up and down in the opposite phase to the sewing needle 11. That is, the surface of the needle hole member 30 where the needle hole 13 is formed is at the same height as or slightly higher than the top surface of the needle plate 101 in the phase where the sewing needle 11 is at its bottom dead point, and is at the lowest position where it is lowered furthest from the top surface of the needle plate 101 in the phase where the sewing needle 11 is at its top dead point.

[0025] The main body 296 slides the lower belts 21-24 in the circumferential direction on the upper part of its outer circumferential surface to feed the workpiece C. For this reason, first to fourth guide portions 291, 292, 293, and 294 for guiding the lower belts 21-24 are provided on the upper part of the outer circumferential surface of the main body 296. The first guide portion 291 is provided to the left rear of the needle hole 13, the second guide portion 292 is provided to the left front of the needle hole 13, the third guide portion 293 is provided to the right front of the needle hole 13, and the fourth guide portion 294 is provided to the right rear of the needle hole 13. Each of the guide portions 291-294 is a protruding strip extending in the front-rear direction, and its width in the left-right direction is equal to or slightly wider than that of each of the lower belts 21-24. The rear end of each of the guide portions 291-294 forms a slope such that the amount of protrusion radially outward from the outer circumferential surface of the main body portion 296 gradually increases toward the front. Also, the front end of each of the guide portions 291-294 forms a slope such that the amount of protrusion radially outward from the outer circumferential surface of the main body portion 296 gradually decreases toward the front.

[0026] The first guide portion 291 is located to the left of the needle hole 13 and rearward of the center of the needle hole 13 over substantially the entire length. The first guide portion 291 has a flat and horizontal guide surface 291a (patterned portion in FIG. 5) forward of the maximum radially outward protrusion of the main body portion 296. The guide surface 291a is disposed so as to face the composite opening 102 of the needle plate 101 when viewed from above. The guide surface 291 a is set so that the outer surface of the rear left lower belt 21 that passes over it in sliding contact therewith is slightly higher than the upper surface of the needle plate 101 . The guide surface 291a is formed so that its front end is located slightly rearward of the center of the needle hole 13 and the rear left lower belt 21 comes into contact with the workpiece C rearward of the center of the needle hole 13.

[0027] The second guide portion 292 is located to the left of the needle hole 13 and to the right of the first guide portion 291, and is located forward of the center of the needle hole 13 over substantially the entire length. The second guide portion 292 has a flat and horizontal guide surface 292a (patterned portion in FIG. 5 ) behind the maximum radially outward protrusion of the main body portion 296. The guide surface 292a is disposed so as to face the composite opening 102 of the needle plate 101 when viewed from above. The guide surface 292 a is set so that the outer surface of the front left lower belt 22 that passes over and slides thereon is slightly higher than the upper surface of the needle plate 101 . The guide surface 292a is formed such that its rear end is located slightly forward of the center of the needle hole 13 and the front left lower belt 22 abuts against the workpiece C forward of the center of the needle hole 13.

[0028] The third guide portion 293 is located to the right of the needle hole 13 and forward of the center of the needle hole 13 over substantially the entire length. The third guide portion 293 has a flat and horizontal guide surface 293a (patterned portion in FIG. 5) behind the maximum radially outward protrusion of the main body portion 296. The guide surface 293a is disposed so as to face the composite opening 102 of the needle plate 101 when viewed from above. The guide surface 293 a is set so that the outer surface of the front right lower belt 23 that passes over and slides thereon is slightly higher than the upper surface of the needle plate 101 . The guide surface 293a is formed such that its rear end is located slightly forward of the center of the needle hole 13 and the front right lower belt 23 abuts against the workpiece C forward of the center of the needle hole 13.

[0029] The fourth guide portion 294 is located to the right of the needle hole 13 and the third guide portion 293 and rearward of the center of the needle hole 13 over substantially the entire length. The fourth guide portion 294 has a flat and horizontal guide surface 294a (patterned portion in FIG. 5 ) forward of the maximum radially outward protrusion of the main body portion 296. The guide surface 294a is disposed so as to face the composite opening 102 of the needle plate 101 when viewed from above. The guide surface 294a is set so that the outer surface of the lower rear right belt 24 that passes over it in sliding contact therewith is slightly higher than the upper surface of the needle plate 101. The guide surface 294a is formed so that its front end is located slightly rearward of the center of the needle hole 13 and the rear right lower belt 24 abuts against the workpiece C rearward of the center of the needle hole 13.

[0030] The guide surfaces 291a, 294a are provided behind the center of the needle hole 13, and the guide surfaces 292a, 293a are provided ahead of the center of the needle hole 13. Therefore, when a speed difference (conveyance difference) is provided between the rear left lower belt 21, rear right lower belt 24 on the rear side and the front left lower belt 22, front right lower belt 23 on the front side, the conveying force due to the front and rear feed speed difference (conveyance difference) can be applied to the sewn material C without interference between the lower belts 21-24. Therefore, a desired stitch is formed in the differential feed in the front and rear direction, and it is possible to improve the sewing quality.

[0031] The first pressure 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, thereby preventing slack from occurring. The first pressure mechanism 33, as shown in FIGS. 2, 3 and 6, has a left pressure roller 331, a right pressure roller 332, a support plate 333, and a base block 334.

[0032] The support plate 333 is a long flat plate extending in the front-rear and up-down directions, and is supported by a base block 334 with its longitudinal direction facing diagonally upward and forward. Furthermore, the support plate 333 supports the left pressure roller 331 and the right pressure roller 332 concentrically and rotatably on the left and right surfaces of the upper end portion thereof. The support plate 333 is disposed so that the left pressure roller 331 and the right pressure roller 332 abut against the outer surface of the belt extending between the guide frame 29 and the first pulley 31 from below the rear portion.

[0033] The base block 334 is shared with the second pressure mechanism 34, which will be described later, and supports the components of the first and second pressure mechanisms 33, 34. The base block 334 is fixedly mounted below the guide frame 29 within the sewing machine bed portion 111. The support plate 333 has an elongated hole along its longitudinal direction, and is fastened to the base block 334 by two bolts inserted into the elongated holes. The longitudinal direction of the support plate 333 is oriented in a direction substantially perpendicular to the belt stretched around the first pulley 31. Therefore, by loosening the bolts and moving the support plate 333 along the elongated holes, it is possible to adjust the pressure contact force of the left pressure roller 331 and the right pressure roller 332 against the belt. In other words, it is possible to adjust the tension of the belt passing between the guide frame 29 and the first pulley 31.

[0034] The left pressure roller 331 and the right pressure roller 332 have the same outer diameter, and are supported by a support plate 333 so as to be rotatable about the same axis along the left-right direction. In addition, the left pressure roller 331 and the right pressure roller 332 each have a width in the left-right direction that is twice or more the width of each of the lower belts 21-24. This allows the left pressure roller 331 to come into contact with both 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 . Similarly, the right pressure roller 332 can be brought into contact with either the front right lower belt 23 or the rear right lower belt 24 stretched between the guide frame 29 and the first pulley 31 .

[0035] The second pressure 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, thereby preventing slack from occurring. As shown in FIGS. 2, 3 and 6, the second pressure mechanism 34 has a left pressure roller 341, a right pressure roller 342, a support plate 343, and the above-mentioned base block 334.

[0036] The support plate 343 has the same structure as the support plate 333 described above, and is supported by the base block 334 with its longitudinal direction facing diagonally upward and rearward. The support plate 343 supports the left pressure roller 341 and the right pressure roller 342 concentrically and rotatably on the left and right surfaces of the upper end portion thereof. The support plate 343 is disposed such that the left pressure roller 341 and the right pressure roller 342 abut against the outer surface of the belt extending between the guide frame 29 and the second pulley 32 from above the rear portion.

[0037] The support plate 343 also has an elongated hole, and the support plate 343 can be moved along the elongated hole. This makes it possible to adjust the pressure contact force of the left pressure roller 341 and the right pressure roller 342 against the belt stretched around the second pulley 32. Therefore, the tension of the belt passing between the guide frame 29 and the second pulley 32 can be adjusted.

[0038] The left pressure roller 341 and the right pressure roller 342 have the same outer diameter, and are supported rotatably about the same axis along the left-right direction by a support plate 343. In addition, the left pressure roller 341 and the right pressure roller 342 each have a width twice or more that of each of the lower belts 21-24. This allows the left pressure roller 341 to come into contact with both 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 . Similarly, the right pressure roller 342 can be brought into contact with either the front right lower belt 23 or the rear right lower belt 24 stretched between the guide frame 29 and the second pulley 32 .

[0039] 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 be brought into contact with 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 be brought into contact with the front right lower belt 23 and the rear right lower belt 24. Therefore, regardless of whether each of the lower belts 21 to 24 is stretched around the first pulley 31 or the second pulley 32, tension is applied by either the first pressure mechanism 33 or the second pressure mechanism .

[0040] FIG. 6 shows the state in which the front left lower belt 22 and the front right lower belt 23, which are fed on the front side of the needle drop position, are hung around the first pulley 31, and the rear left lower belt and the rear right lower belt 21, 24, which are fed on the rear side, are hung around the second pulley 32. FIG. 7 shows the state in which the rear left lower belt 21 and the front left lower belt 22, which are fed to the left of the needle drop position, are hung on the first pulley 31, and the front right lower belt 23 and the rear right lower belt 24 are hung on the second pulley 32.

[0041] The lower belts 21 to 24 can be easily removed from the pulleys 31 and 32 and replaced by loosening the bolts and moving the pressure rollers 331, 332, 341, and 342 backward. Therefore, sewing in the hanging state of FIG. 6 and sewing in the hanging state of FIG. 7 can be easily selected.

[0042] For example, in the passing state of FIG. 6 (front and rear differential feed state), it is possible to perform so-called shirring stitches in which the front side of the needle drop position is fed faster than the rear side. In addition, in the front and rear differential feed state, the front side of the needle drop position is fed slower than the rear side, so that sewing can be performed with tension applied to the workpiece C.

[0043] In the crossover state of FIG. 7 (left and right differential feed state), if the left side is fed quickly, a curved stitch that curves to the right can be made, and if the right side is fed quickly, a curved stitch that curves to the left can be made. In addition, since the curvature can be changed according to the difference in speed (difference in conveying amount) between the left and right sides, it is possible to sew a variety of curved lines.

[0044] [Fabric holding mechanism] Fig. 8 is a perspective view of the presser mechanism 70 as a presser mechanism for pressing down the sewing material C on the needle plate 101 from above, Fig. 9 is a rear view, and Fig. 10 is a right side view. Note that Figs. 8 and 10 omit illustration of a positioning ruler 50 and its support mechanism 53, which will be described later.

[0045] The cloth presser mechanism 70 includes a presser foot 71, a presser bar 72, a mounting base 74, a presser motor (not shown), and a presser height detector (not shown). The presser bar 72 is disposed adjacent to the front of the needle bar 12 and is supported within the sewing machine arm portion 113 so as to be vertically movable along the vertical direction.

[0046] The upper end of the presser bar 72 is pressed downward by a presser spring (not shown) inside the sewing machine arm portion 113. The amount of expansion and contraction of the presser spring can be adjusted by a presser motor, the amount of movement of which can be controlled as desired. Therefore, by controlling the presser motor, the presser pressure of the presser foot 71 can be set as desired. The presser motor also performs a lifting operation to switch between a presser height at which the presser foot 71 presses the sewing workpiece C on the needle plate 101 and a release height at which the presser foot 71 is spaced upward.

[0047] In addition, a presser height detector (not shown) for detecting the height of the presser bar 72 is provided together with the presser bar 72. Therefore, after the presser pressure of the presser foot 71 is set to a specified value, if the height of the presser foot 71 changes due to a change in the thickness of the workpiece C, the presser pressure can be maintained at a constant set value by controlling the presser motor so that the amount of expansion and contraction of the presser spring does not change.

[0048] The presser foot 71 is attached to the lower end of the presser bar 72 via a mounting base 74. The mounting base 74 is a block with horizontal and flat upper and lower surfaces. The mounting base 74 has an insertion hole formed therethrough from top to bottom, into which the presser bar 72 can be inserted. The mounting base 74 is fixed to the lower end of the presser bar 72 by, for example, fastening with screws. Further, a lower end of a link member 474 of the upper feed mechanism 40 (described later) is connected to the front end of the mounting base 74 so as to be rotatable about an axis extending in the left-right direction.

[0049] The presser foot 71 is disposed above the composite opening 102 of the needle plate 101. The presser foot 71 presses the workpiece C from above, and appropriately transmits the conveying force of the lower belts 21-24 to the workpiece C. The presser foot 71 also supports the upper left belt 41 and the upper right belt 42 of the upper feed mechanism 40 so that they can be conveyed. The presser foot 71 also has the function of pressing the upper belts 41, 42 against the workpiece C, and appropriately transmitting the conveying force to the workpiece C.

[0050] As shown in FIGS. 8 to 10, the presser foot 71 has a bottom plate 711 that presses down the sewing material C from above, and a connecting portion 712 that is attached to the lower end of the presser bar 72.

[0051] The bottom plate 711 has a smooth bottom surface and an upstream side (rear end) in the cloth feeding direction that is curved upward to form a so-called boat shape. The connecting part 712 is erected on the upper surface of the front end part of the bottom plate 711, and is connected to the bottom plate 711 so as to be able to swing somewhat around an axis along the left-right direction. An upper part of the connecting part 712 is fixed to the underside of the mounting base 74, for example, by screwing. The connecting part 712 may be joined to the mounting base 74 by welding or the like, or the connecting part 712 and the mounting base 74 may be configured as a single integrated member.

[0052] [Upper feed mechanism] As shown in Figures 1, 2, and 8 to 10, the upper feed mechanism 40 includes an upper left belt 41 and an upper right belt 42 as conveying belts, the left and right belt guides 43, 44 mentioned above, an upper left motor 45 that serves as a drive source for belt feed of the upper left belt 41, an upper right motor 46 that serves as a drive source for belt feed of the upper right belt 42, and a guide mechanism 47 that guides each of the upper belts 41, 42 from each of the upper motors 45, 46 to the presser foot 71.

[0053] The left and right belt guides 43, 44 are provided on the left and right sides of the presser foot 71. The belt guides 43 and 44 are rotatably attached to the left and right side surfaces of the lower part of the connecting portion 712 of the presser foot 71 by means of a support shaft (not shown) that extends in the left-right direction.

[0054] In a side view, each of the belt guides 43, 44 has a front end that extends obliquely upward toward the front, a rear end that is closest to the needle plate 101, and a rear end that rises obliquely upward toward the rear. Each of the belt guides 43, 44 is provided at its rear end with a feed roller 432, 442 that can rotate about a shaft extending in the left-right direction. The left and right endless annular upper belts 41, 42 are guided to pass between the left and right belt guides 43, 44 and the side surfaces of the presser foot 71. That is, the left and right upper belts 41, 42 are folded back downward from above the feed rollers 432, 442 along the outer periphery, and are guided to proceed forward along the portion of each belt guide 43, 44 that is closest to the needle plate 101, and then pass through in an obliquely upward forward direction. As each upper belt 41, 42 proceeds forward along the portion of each belt guide 43, 44 that is closest to the needle plate 101, it abuts against the workpiece C on the needle plate 101 and feeds it forward. In addition, the contact position of the upper left belt 41 with the workpiece C overlaps with the contact position of the front left lower belt 22 with the workpiece C in a plan view, and the workpiece C is fed so as to be sandwiched between these belts. Similarly, the contact position of the upper right belt 42 with the workpiece C overlaps with the contact position of the front right lower belt 23 with the workpiece C in a plan view, and the workpiece C is fed so as to be sandwiched between these belts.

[0055] As described above, each belt guide 43, 44 is pivotally supported by a support shaft on the presser foot 71. One end of the tension spring 433, 443 is connected to the shaft 434, 444 provided at the front end of each belt guide 43, 44. The other end of each tension spring 433, 443 is connected to the shaft 745, 746 provided on the left and right side portions of the mounting base 74, respectively, and applies upward tension to the front end of each belt guide 43, 44. As a result, the rear end sides of the belt guides 43, 44 are urged to rotate downward, and a pressing force is applied to each of the upper belts 41, 42 moving forward along the portion closest to the needle plate 101 toward the needle plate 101. As a result, a pressing force is applied to each of the upper belts 41, 42 against the workpiece C on the needle plate 101.

[0056] The left and right upper motors 45, 46 are motors whose rotation speed can be controlled, such as a DC motor, an AC motor, or a stepping motor. The upper left motor 45 is supported on the front side of the left end of the sewing machine arm portion 113 via a motor bracket 451 with the output shaft facing leftward. 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 of the sewing machine arm portion 113 with its output shaft facing leftward.

[0057] 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. Further, a motor pulley 462 is provided on 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.

[0058] The upper-left belt 41 is an endless loop, and one end of the loop is stretched out and hung around the motor pulley 452 of the upper-left motor 45 , and the other end is hung around the feed roller 432 of the belt guide 43 . The upper right belt 42 is also an endless loop, and one end of the loop is stretched out and hung around the motor pulley 462 of the upper right motor 46, and the other end is hung around the feed roller 442 at the rear end of the belt guide 44 mentioned above.

[0059] The path of the upper left belt 41 from the motor pulley 452 to the feed roller 432 and the path of the upper right belt 42 from the motor pulley 462 to the feed roller 442 overlap each other when viewed from the left-right direction, except for the periphery of the motor pulleys 452, 462. The upper right belt 42 is disposed on the right side of the upper left belt 41.

[0060] The guide mechanism 47 guides the upper left belt 41 and the upper right belt 42 along the respective paths described above. The guide mechanism 47 has a pair of first tension rollers 471 lined up on the left and right, a pair of second tension rollers 472 lined up on the left and right, a guide arm 475 consisting of upper and lower link members 473, 474, and a plurality of guide rollers 476 rotatably mounted at various portions on the path of each of the upper belts 41, 42.

[0061] The pair of first tension rollers 471 are disposed below the motor pulley 452. The pair of second tension rollers 472 are disposed between the motor pulley 452 and the pair of first tension rollers 471. 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 press against both the upper left belt 41 and the upper right belt 42 from the outside to apply inward tension to them. The pair of second tension rollers 472 is rotatable about an axis along the left-right direction and has a narrow axial width. The pair of second tension rollers 472 presses against only the upper right belt 42 from the inside to apply outward tension. In addition, the upper right belt 42 is expanded to the left and right sides by the pair of second tension rollers 472, so that interference with the motor pulley 452 located midway along the path can be avoided.

[0062] An upper link member 473 constituting a guide arm 475 has one end connected to a lower end of the motor bracket 451 so as to be rotatable about an axis along the left-right direction. The other end of the upper link member 473 is connected to one end of the lower link member 474 so as to be rotatable about an axis along the left-right direction. 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 about an axis extending in the left-right direction.

[0063] At the connection between the upper link member 473 and the lower link member 474, a guide roller 476 is provided that contacts the inside of the loop from the front side for the upper left belt 41 and the upper right belt 42, and a guide roller (not shown) is provided that contacts the outside of the loop from the front side. As a result, the left and right upper belts 41, 42 are transported along a path along the upper link member 473 and a path along the lower link member 474. Therefore, even if the presser foot 71 rises and falls due to a change in thickness or unevenness of the sewing material C, causing a change in the bending angle between the upper link member 473 and the lower link member 474, the left and right upper belts 41, 42 maintain a path along the upper link member 473 and a path along the lower link member 474. Therefore, the path length of each upper belt 41, 42 is maintained constant, and fluctuations in tension can be suppressed.

[0064] [Positioning ruler] The positioning ruler 50 is for positioning the side end of the workpiece C in a direction (left-right direction) perpendicular to the feed direction of the workpiece C. The direction in which the positioning ruler 50 is positioned is preferably perpendicular to the feed direction of the workpiece C, but is not limited thereto, and may be inclined to some extent with respect to the perpendicular direction. FIG. 11 is a perspective view of the positioning ruler 50 and its surrounding structure in the non-use position, and FIG. 12 is a perspective view of the positioning ruler 50 and its surrounding structure in the use position. As shown in FIGS. 9, 11 and 12, the positioning ruler 50 is supported by a support mechanism 53.

[0065] The positioning ruler 50 is an abutment plate against which a side edge (the right edge in this embodiment) of the sewing workpiece C on the needle plate 101 is abutted, thereby performing sewing (so-called edge stitching) at regular intervals along the side edge. In the following description, the regular interval of the edge stitching performed along the side edge of the sewing workpiece C is referred to as the "edge stitch width."

[0066] The positioning ruler 50 is switched by a support mechanism 53 between a use position in which it is close to or in contact with the upper surface of the needle plate 101 and a non-use position in which it is spaced upward from the upper surface of the needle plate 101. Here, the position and orientation of each part of the positioning ruler 50 will be described assuming that it is in the use position.

[0067] The positioning ruler 50 has an abutment plate 51 against which the side end of the sewing workpiece C abuts, and a connecting portion 52 extending from the abutment plate 51 toward the support mechanism 53. The abutment plate 51 and the connecting portion 52 are formed by bending a single metal plate.

[0068] The abutment plate 51 is a flat plate parallel to the front-rear and up-down directions, and its left surface serves as an abutment surface for the sewing workpiece C. The abutment plate 51 is generally rectangular in shape when viewed from the side, and is long in the front-rear direction. The lower edge of the abutment plate 51 is straight and, in the use position, the lower edge is horizontal along the front-to-rear direction and can abut or come close to the upper surface of the needle plate 101 over the entire length of the lower edge.

[0069] In the use position, the front end of the abutment plate 51 is preferably at the same position as the pinhole 13 or further forward in the front-rear direction. The width of the edge stitch during sewing is the left-right distance from the center of the needle hole 13 to the left surface of the abutment plate 51. The left-right distance from the center of the needle hole 13 to the left surface of the abutment plate 51 can be adjusted by the support mechanism 53. The abutment plate 51 is disposed so that its left surface is to the right of the center of the needle hole 13. The position of the abutment plate 51 can be adjusted so that its left surface approaches the closest position to the center of the needle hole 13 in the left-right direction, within a range that does not interfere with the sewing needle 11 or the presser foot 71.

[0070] The connecting part 52 extends rightward from the upper front edge of the abutment plate 51 and has a crank shape when viewed from the front-rear direction. Due to this crank shape, the right end of the connecting part 52 is one step higher than the end on the abutment plate 51 side. The right end of the connecting part 52 is connected to a support mechanism 53, and the entire positioning ruler 50 is supported by the support mechanism 53. The arrangement and shape of the connecting portion 52 are not limited to those described above. For example, the connecting portion 52 may be arranged in any position relative to the abutment plate 51 so long as it does not prevent the side end of the sewn material C from being abutted against the abutment surface, and may be connected to any of the outer edges of the abutment plate 51. The connecting portion 52 does not have to be flat, and furthermore, it does not have to be integral with the abutment plate 51.

[0071] The support mechanism 53 has a holding shaft 54 ​​that holds the positioning ruler 50, a cylindrical body 55 through which the holding shaft 54 ​​is inserted, a rotating arm 56 that holds the cylindrical body 55, and an actuator (not shown) as a drive source that imparts a rotating motion to the rotating arm 56. The support mechanism 53 rotates the positioning ruler 50 to switch between the use position and the non-use position.

[0072] The holder shaft 54 ​​has a round bar-shaped shaft portion 541 extending in the left-right direction, and a holder block 542 fixedly provided to the left end portion of the shaft portion 541. Holding block 542 is a substantially rectangular parallelepiped extending leftward from the left end of shaft portion 541. The left end of the upper surface of holding block 542 has a stepped portion with a downward drop, and the right end of connecting portion 52 is connected to the upper surface of the stepped portion with its lower surface abutting thereon by a fastening member such as a bolt.

[0073] The shaft portion 541 of the holder shaft 54 ​​has a uniform outer diameter over its entire length in the left-right direction, and its right end portion is inserted into the cylindrical body 55 . The cylindrical body 55 is disposed along the left-right direction, and is fixed by embracing the holding shaft 54 ​​with a fastening member such as a bolt. Therefore, by loosening the fastening member, the holding shaft 54 ​​and the positioning ruler 50 can be rotated around an axis along the left-right direction to adjust the orientation.

[0074] The rotating arm 56 has an extendable shaft 561 that holds the cylindrical body 55, and a cylindrical arm portion 562 into which the extendable shaft 561 can be inserted. The base end of the cylindrical arm 562 is supported by a sewing machine frame or other support structure so as to be rotatable about an axis along the left-right direction. The cylindrical arm 562 extends in a radial direction centered on the rotation axis of the base end. Specifically, the cylindrical arm 562 extends generally rearward from the base end.

[0075] The tubular arm 562 is cylindrical in shape into which the telescopic shaft 561 can be inserted, and holds the telescopic shaft 561 with a fastening member such as a bolt. The tubular arm 562 can adjust the position of the telescopic shaft 561 along the insertion direction by loosening the fastening member. That is, the rotating arm 56 expands and contracts the telescopic shaft 561 along the direction of the rotation radius of the tubular arm 562, making it possible to adjust the rotation radius in the rotation operation of the positioning ruler 50. This allows the positioning of the positioning ruler 50 in the front-rear direction at the usage position to be adjusted.

[0076] The telescopic shaft 561 holds the cylindrical body 55 facing in the left-right direction at the rotating end on the rear end side. An adjustment screw 563 is provided at the rotating end of the telescopic shaft 561. By rotating the adjustment screw 563, the position of the cylindrical body 55 can be adjusted in the left-right direction. Therefore, the position of the positioning ruler 50 can be adjusted in the left-right direction by the adjustment screw 563 through the cylindrical body 55 and the holding shaft 54, thereby adjusting the edge stitch width.

[0077] The actuator is composed of a motor, a rotary air cylinder, etc., which rotates the rotating arm 56. Also, a plunger of a direct acting air cylinder may be connected to the rotating arm 56 to rotate it. The actuator applies an action of moving the positioning ruler 50 toward or away from the needle plate 101 through the rotation of the rotating arm 56. In this way, the actuator applies an action of switching the position of the positioning ruler 50 between the use position and the non-use position.

[0078] In the non-use position, the pivot arm 56 is generally horizontally aligned in the front-to-rear direction, the pivot end on the positioning ruler 50 side faces rearward, and the positioning ruler 50 is spaced upward from the needle plate 101. Then, by driving the actuator, the rotating arm 56 rotates at its rotating end diagonally downward and forward, and the positioning ruler 50 descends to the use position where it abuts on or is close to the upper surface of the needle plate 101. Furthermore, when the actuator is driven in the opposite direction to the above, the pivot arm 56 pivots in the opposite direction to the above, and the positioning ruler 50 moves from the use position to the non-use position. There is no restriction on the height of the positioning ruler 50 in the unused position, but it is preferable that the height be such that it does not interfere with other components of the sewing machine 100 and does not hinder the sewing operation.

[0079] [Evacuation mechanism] The left and right belt guides 43, 44 are located at feeding positions where the bottoms of their rear ends are at the same height as the upper surface of the needle plate 101 when feeding the sewing material. When sewing using the positioning ruler 50, the retraction mechanism 60 moves the right-side belt guide 44 and feed roller 442, which are on the side of the positioning ruler 50 relative to the needle hole 13, and the upper right belt 42, which is guided by these, to a retracted position in order to position the positioning ruler 50. As described above, the positioning ruler 50 is arranged in the use position so that the front end of the positioning ruler 50 in the front-rear direction is located at the same position as the needle hole 13 or further forward than the needle hole 13. Furthermore, the positioning ruler 50 may be arranged so that the left surface of the abutment plate 51 is closest to the center of the needle hole 13 in the left-right direction, within a range that does not interfere with the sewing needle 11.

[0080] The right belt guide 44 is disposed so that its rear end, which is the part closest to the needle hole 13 (the needle drop position), overlaps with the needle hole 13 in the front-to-rear direction. The right belt guide 44, the feed roller 442, and the upper right belt 42 guided by them are disposed adjacent to the right of the needle hole 13 in the left-to-right direction. For this reason, there is a risk of interference between the right-side belt guide 44 and the feed roller 442, and the upper right belt 42 and positioning ruler 50 guided by them, if one attempts to position the positioning ruler 50 close to the pinhole 13 in the usage position. For this reason, the retraction mechanism 60 moves the rear end of the belt guide 44 to a retracted position spaced upward from the needle plate 101, thereby avoiding interference between the right-side belt guide 44 and feed roller 442 and the upper right belt 42 and positioning ruler 50 that are guided by them.

[0081] Fig. 13 is a perspective view of the periphery of the retraction mechanism 60, and Fig. 14 is a right side view. The positioning ruler 50 and its support mechanism 53 are omitted from Figs. As shown in Figures 8, 10, 13 and 14, the retraction mechanism 60 has a retaining member 61 that retains the right-side belt guide 44 in the retracted position, a support shaft 62 that rotatably supports the upper end of the retaining member 61, and a torsion coil spring (torsion spring) 63 as an elastic member that biases the retaining member 61 toward a predetermined position.

[0082] The upper end of the holding member 61 is supported on the right side surface of the mounting base 74 by a support shaft 62 made of a stepped screw so as to be rotatable about an axis in the left-right direction. The holding member 61 is made of a rectangular flat plate, and extends in a radial direction with its lower end serving as a rotating end, centered on the support shaft 62. A substantially semicircular recess 611 is formed in the lower end of the holding member 61. Further, on the front side of the lower end of the holding member 61, an operation piece 612 is formed which is bent and raised to the right.

[0083] 8 and 10, the lower end of the holding member 61 is biased forward by a torsion coil spring 63. The lower end of the holding member 61 is pressed against the head of a bolt that connects the lower end of the link member 474 to the mounting base 74, and is maintained in a release position spaced forward from the front end of the belt guide 44. When the holding member 61 is in the release position, it does not interfere with the belt guide 44, and the belt guide 44 maintains the feeding position.

[0084] 13 and 14, when the operation piece 612 at the lower end of the holding member 61 is pressed and rotated rearward while the front end is pressed down so that the belt guide 44 is in the retracted position, the shaft portion 444 can be fitted into the recess 611 from below. The position where the shaft portion 444 is fitted into the recess 611 is determined as the holding position of the holding member 61. When the holding member 61 is in the holding position, the holding member 61 faces substantially vertically downward. In this case, the front end of the belt guide 44 maintains a state in which the shaft portion 444 is fitted in the recess 611 due to the upward tension of the tension spring 443. This allows the holding member 61 to maintain the holding position against the torsion coil spring 63. Therefore, the belt guide 44 is held in the retracted position.

[0085] To return the belt guide 44 to the sending position, the front end of the belt guide 44 is pushed down or the rear end is pulled up. This disengages the shaft 444 from the recess 611, and the holding member 61 is returned to the release position by the torsion coil spring 63. Therefore, the belt guide 44 can also be returned to the sending position.

[0086] [Use of sewing machine] The sewing machine 100 having the above configuration is capable of performing sewing with upper belt feed and lower belt feed. In this case, the lower feed mechanism 20 can perform sewing by feeding the front side and rear side of the needle hole 13 at different speeds by looping the lower belts 21 to 24 in the manner shown in FIG. In addition, the lower feed mechanism 20 can perform sewing by feeding the left and right sides of the needle hole 13 at different speeds by looping the lower belts 21 to 24 in the manner shown in FIG.

[0087] On the other hand, when sewing the right edge of the sewing workpiece C, the front end of the right belt guide 44 is pressed down to move it from the feed position to the retreated position, as shown in Figs. Furthermore, the lower end of the holding member 61 is rotated rearward to switch it from the release position to the holding position, and the shaft portion 444 of the belt guide 44 is fitted into the recess 611. The holding member 61 holds the shaft portion 444 so that the distance therebetween is sufficiently longer than the distance between the shaft portion 444 and the shaft portion 746 of the belt guide 44 when the belt guide 44 is in the feed position, so that the belt guide 44 can be held in the retracted position. Then, the rear end portion of the belt guide 44 is separated upward from the needle plate 101, and a space is formed around the right side of the needle hole 13. Then, the actuator of the support mechanism 53 of the positioning ruler 50 is driven to move the positioning ruler 50 from the non-use position to the use position. As a result, the lower edge of the abutment plate 51 of the positioning ruler 50 comes into contact with or is close to the upper surface of the needle plate 101, with the abutment plate 51 aligned in the front-to-rear direction on the upper surface of the needle plate 101 and to the right of the needle hole 13. The left-to-right position of the abutment plate 51 is previously adjusted so that it is the target edge stitch width from the center of the needle hole 13.

[0088] As a result, sewing is performed while feeding the workpiece C so that the right end of the workpiece C always abuts against the left surface of the abutment plate 51 of the positioning ruler 50, thereby sewing with the targeted edge stitch width. In addition, in the case of this sewing, since the upper right belt 42 does not contribute to feeding the sewing workpiece C, it is preferable that the worker sews while manually operating the sewing workpiece C so that the sewing workpiece does not bend too far to the right.

[0089] Furthermore, the control device that controls the upper right motor 46, which is the drive source of the upper right belt 42, may perform control to restrict the upper right motor 46 from being driven during edge stitching. In this case, a sensor may be provided to detect any one of the movement of the belt guide 44 to the retracted position, the movement of the holding member 61 to the holding position, and the movement of the positioning ruler 50 to the use position, and the control device may perform control to restrict the drive of the upper right motor 46 in conjunction with the detection by the sensor. The control device may also be configured to perform control to restrict the driving of the upper right motor 46 in conjunction with the driving of the actuator that switches the position of the positioning ruler 50 to the use position.

[0090] [Technical effect of the first embodiment] The sewing machine 100 has a retraction mechanism 60 that holds the upper right belt 42 and the belt guide 44 on the side of the positioning ruler 50 relative to the needle hole 13, which is the needle drop position, in a retracted position away from the needle hole 13. This allows the positioning ruler 50 to be positioned on the needle plate 101 close to the needle hole 13 without interference from the upper right belt 42 and the belt guide 44, making it possible to sew a narrower edge stitch width.

[0091] In addition, since the retraction mechanism 60 retracts the upper right belt 42 and belt guide 44 upward, the positioning ruler 50 can be positioned without restrictions not only left and right but also in the front-to-back direction. By positioning the positioning ruler 50 so that it overlaps with the needle hole 13 in the front-to-back direction, better edge stitching can be performed.

[0092] In addition, since the retraction mechanism 60 has a retaining member 61 that retains the belt guide 44 in the retracted position after it has been rotated, the retaining state can be maintained by utilizing the restoring force of the tension spring 443 of the belt guide 44, thereby making it possible to simplify the configuration of the retraction mechanism 60 and reduce the number of parts.

[0093] In addition, since the positioning ruler 50 is supported by the support mechanism 53 so that it can be moved toward and away from the needle plate 101 or the needle hole 13, the positioning ruler 50 can be placed on the needle plate 101 only when necessary, such as when sewing on the edge, and the sewing machine 100 can perform a variety of sewing operations in addition to edge sewing.

[0094] In addition, since the support mechanism 53 has an actuator that moves the positioning ruler 50 toward or away from the needle plate 101 or the needle hole 13, the position of the positioning ruler 50 can be quickly changed when necessary, such as for edge stitching, thereby improving the efficiency of sewing work.

[0095] [Second embodiment] The second embodiment of the present invention will now be described in detail. In this embodiment, a sewing machine in which the retraction mechanism is constituted by a holding member 61A having a structure different from that of the holding member 61 described above is shown. Fig. 15 is a perspective view of the periphery of holding member 61A in the released position, Fig. 16 is a right side view of the same, Fig. 17 is a perspective view of the periphery of holding member 61A in the held position, Fig. 18 is a right side view of the same, Fig. 19 is a perspective view of holding member 61A, Fig. 20 is a plan view of the same, and Fig. 21 is a right side view of the same.

[0096] 19 to 21, the holding member 61A has a through hole 615A formed at one end into which can be inserted the shaft 444 for hanging the tension spring 443 provided at the front end of the belt guide 44. Unlike the holding member 61, one end of the holding member 61A is supported at the front end of the belt guide 44 so as to be rotatable about an axis along the left-right direction. A spring washer may be interposed between the holding member 61A and the belt guide 44 to add sliding resistance to the rotation operation.

[0097] Moreover, a substantially semicircular recess 611A is formed at the other end of the holding member 61A. Unlike the holding member 61 described above, this recess 611A is for fitting a shaft 746 for hanging a tension spring 443 provided on the presser mechanism 70 side. In the second embodiment, the shaft portion 746 is illustrated as being provided on the upper right side surface of the connecting portion 712 rather than on the mounting base 74, but the shaft portion 746 may be provided on the mounting base 74.

[0098] Furthermore, the holding member 61A is formed with a hook portion 614A extending in the thickness direction of the holding member 61A at a side edge portion in the middle portion in the longitudinal direction. 15 and 16, when the holding member 61A supported on the right side of the belt guide 44 is in the released position, if the rotating end side hangs down, it may get caught on the sewing workpiece C, interfere with other members, or damage the needle plate 101. Therefore, to prevent the holding member 61A from hanging down, the hook portion 614A is engaged with the upper surface of the belt guide 44 to function as a stopper.

[0099] [Use of sewing machine] In the case of the above configuration, when sewing the edge, as shown in Figures 15 and 16, with the holding member 61A in the release position, the front end of the right belt guide 44 is pressed down and rotated from the feed position to the retracted position. 17 and 18, the rotating end of the holding member 61A is rotated upward to switch from the release position to the holding position, and the shaft portion 746 of the belt guide 44 is fitted into the recess 611A. The holding member 61A is sufficiently longer than the distance between the shaft portion 444 and the shaft portion 746 of the belt guide 44 when the belt guide 44 is in the feed position, and therefore can hold the belt guide 44 in the retracted position. This allows the positioning ruler 50 to be positioned closer to the needle hole 13 on the right side of the needle hole 13 on the needle plate 101, thereby allowing the edge stitching to be performed.

[0100] [Technical effect of the second embodiment] A sewing machine equipped with a holding mechanism made up of holding member 61A has the same technical effects as sewing machine 100 of the first embodiment described above. Furthermore, the holding member 61A does not require a torsion coil spring or a shoulder screw, and the holding mechanism can be configured more simply. However, a spring may be provided to bias the rotating end of the holding member 61A downward.

[0101] [Third embodiment] In the third embodiment, a sewing machine is provided with a retraction mechanism 60B that switches between a feed position and a retracted position of a belt guide 44B by an actuator 65B. Fig. 22 is a right side view showing the configuration around the retraction mechanism 60B.

[0102] In this sewing machine, the belt guide 44B can be switched from the feed position to the retracted position by a pressing force, and a pressure receiving portion 445B for receiving the pressing force for switching the position is provided at the upper end of the belt guide 44B. The pressure receiving portion 445B is formed in a flat plate shape along the up-down and left-right directions. The belt guide 44B has the same configuration as the belt guide 44 described above, except for the pressure receiving portion 445B.

[0103] The retraction mechanism 60B has a bell crank-shaped holding member 64B having extensions 641B, 642B extending in two directions, and an actuator 65B that applies a rotational motion to the holding member 64B.

[0104] The holding member 64B is supported rotatably about an axis along the left-right direction on the right side surface of the mounting base 74. One extension portion 641B of the holding member 64B extends downward, and its tip portion faces the pressure-receiving portion 445B of the belt guide 44B on the rear side of the pressure-receiving portion 445B. The other extension 642B of the holding member 64B extends forward. An upward rotation motion is input to this extension 642B by the actuator 65B. When an upward rotation motion is input to the other extension portion 642B, one extension portion 641B rotates forward, and the upper end portion of the belt guide 44B is pressed forward through the pressure-receiving portion 445B, causing the rear end portion of the belt guide 44B to rotate upward and switch from the feed position to the retracted position.

[0105] Actuator 65B is an actuator that performs linear motion, and may be, for example, an air cylinder. Actuator 65B made of an air cylinder is disposed with plunger 651B facing downward, and the tip of plunger 651B is bent backward to form a hook shape. An upper surface of the hook-shaped tip of the plunger 651B faces a lower surface of the tip of the other extension portion 642B of the holding member 64B. This allows the plunger 651B of the actuator 65B to be retracted upward, thereby rotating the other extension portion 642B of the holding member 64B upward, and switching the belt guide 44B to the retracted position.

[0106] Furthermore, by appropriately setting the stroke of the plunger of the actuator 65B, which is an air cylinder, the belt guide 44B can be held in the retracted position. The presser foot 71 is lowered onto the needle plate 101 during sewing, but is pulled upward by the presser motor to release the workpiece C when sewing is being performed. In the retraction mechanism 60B, the upper surface of the tip of the plunger 651B faces the lower surface of the tip of the other extension 642B of the holding member 64B, so that the lifting operation of the presser foot 71 when released is not affected.

[0107] It is preferable that the actuator 65B is configured so that its operation can be controlled by a control device through an electromagnetic valve, etc. This allows the actuator 65B to be controlled in response to an instruction input operation by an operator, and makes it possible to arbitrarily switch the belt guide 44B between the feed position and the retracted position. As a result, when the positioning ruler 50 is placed on the needle plate 101 to perform edge stitching, the position of the belt guide 44B can be quickly changed, thereby improving the efficiency of the sewing work.

[0108] [Fourth embodiment] The fourth embodiment also shows a sewing machine including a retraction mechanism 60C for switching between the feed position and the retracted position of the belt guide 44B by an actuator 65C. Fig. 23 is a right side view showing the configuration around the retraction mechanism 60C.

[0109] The retraction mechanism 60C has a bell crank-shaped holding member 64C having extensions 641C, 642C extending in two directions, an actuator 65C that imparts a rotational motion to the holding member 64C, and two link members 66C, 67C that connect the holding member 64C and the actuator 65C.

[0110] The holding member 64C has substantially the same configuration as the holding member 64B described above, and has one extension portion 641C that extends downward and the other extension portion 642C that extends forward. The front end of the other extension 642C is connected to an actuator 65C via two link members 66C and 67C.

[0111] The actuator 65C is an actuator that performs linear motion, similar to the actuator 65B described above, and may be, for example, an air cylinder. The lower end of a plunger 651C of an actuator 65C made up of an air cylinder is connected to the front end of the other extension 642C of the holding member 64C via two link members 66C and 67C.

[0112] The lower link member 66C has a lower end connected to a front end of the other extension 642C of the holding member 64C so as to be rotatable about an axis along the left-right direction, and an upper end of the link member 66C is connected to a lower end of the upper link member 67C so as to be rotatable about an axis along the left-right direction. The upper end of the upper link member 67C is connected to the lower end of a plunger 651C of the actuator 65C so as to be rotatable about an axis extending in the left-right direction.

[0113] In addition, in a state where one extension portion 641C of the holding member 64C faces downward and the other extension portion 642C faces forward (a state where the belt guide 44B is in the sending position), the lengths of the two link members 66C, 67C are set so that they are slightly bent at their connecting portions as shown in Fig. 23. Note that the lengths of the two link members 66C, 67C may be set so that they are linear in this state. On the other hand, the upward pulling stroke of the plunger 651C of the actuator 65C is set to a length sufficient to stretch the two link members 66C, 67C into a straight state and further rotate the holding member 64C to rotate the belt guide 44B from the feed position to the retracted position. As a result, by retracting the plunger 651C of the actuator 65C, the two link members 66C, 67C are stretched and the other extension portion 642C of the holding member 64C is rotated upward, thereby switching the belt guide 44B to the retracted position.

[0114] In the retraction mechanism 60C, the tip of the plunger 651C is connected to the holding member 64C via two slightly bent (or linearly connected) link members 66C, 67C, so that when the presser foot 71 is lifted to release it, the two link members 66C, 67C only bend significantly, and do not affect the lifting action of the presser foot 71.

[0115] It is preferable that the actuator 65C is configured so that its operation can be controlled by a control device. As a result, when the positioning ruler 50 is placed on the needle plate 101 to perform edge stitching, the position of the belt guide 44B can be quickly changed, thereby improving the efficiency of the sewing work.

[0116] [Fifth embodiment] The fifth embodiment illustrates a sewing machine including a belt guide 44D that can move from a feed position to a retreat position by forward movement. Fig. 24 is a right side view of the belt guide 44D. The belt guides 44, 44B described above are both configured to move their rear ends, which are in contact with or close to the workpiece C, upwardly and away from each other to switch to the retracted position. In the belt guide 44D of the fifth embodiment, a shaft hole 446D of a support shaft 431 that rotatably supports the belt guide 44D is an elongated hole along the front-rear direction, so that the belt guide 44D is rotatable and can move forward from the feed position. In this case, the retreated position of the belt guide 44D becomes the feed position, and the advanced position becomes the retreated position. When the belt guide 44D is mounted, the retracting mechanism is preferably configured to pull the belt guide 44D forward and hold it.

[0117] [others] Above, each embodiment of the present invention has been described. However, the present invention is not limited to the above-mentioned embodiments. For example, in the embodiments, a component integrally formed from a single member may be replaced with a component divided into a plurality of members and connected or fixed to each other. Also, a component formed by connecting a plurality of members may be replaced with a component integrally formed from a single member. In addition, the details shown in the embodiments can be appropriately changed without departing from the spirit of the invention.

[0118] For example, in each of the above embodiments, a configuration has been exemplified in which the right end portion of the workpiece C is abutted against the positioning ruler 50 to perform edge sewing, but the left end portion of the workpiece C may also be abutted against the positioning ruler to perform edge sewing. In this case, the positioning ruler is disposed to the left of the needle hole 13, and the left end of the workpiece C is brought into contact with the right surface of the abutment plate. Also, it is preferable to switch the left belt guide 43, rather than the right belt guide 44, from the feed position to the retracted position, and to dispose a holding member to the left of the presser foot 71.

[0119] In addition, in each of the above embodiments, a configuration has been exemplified in which only one side of the belt guides 44, 44D is switched to the retracted position to perform edge sewing. However, in cases where the presser foot is configured to press the sewn material C against the lower belts 21-24 and the feed function of the lower belts 21-24 can be maintained even when the upper belts 41, 42 are retracted, a configuration may be provided which includes a retraction mechanism that maintains both belt guides 43, 44 in the retracted position when the positioning ruler 50 is placed in the usage position.

[0120] Additionally, the positioning ruler 50 may be configured to be manually switched between the non-use position and the use position. In addition, the positioning ruler 50 may be configured to be detached and removed from the needle plate 101 when not in use, and to be attached to the needle plate 101 with screws or the like when in use. [Explanation of symbols]

[0121] 11 Sewing Needle 12 Needle bar 13 Needle hole (needle drop position) 20 Lower feed mechanism 21 Rear left lower belt 22 Front left lower belt 23 Front right lower belt 24 Rear right lower belt 40 Upper feed mechanism 41 Upper left belt (conveyor belt) 42 Upper right belt (conveyor belt) 43,44,44B,44D Belt guide 45 Upper left motor 46 Top Right Motor 50 Positioning Ruler 51 Stop plate 52 Connecting part 53 Support mechanism 60,60B,60C Evacuation mechanism 61, 61A, 64B, 64C Retaining member 63 Coil Spring 65B, 65C Actuator 66C, 67C Link members 70 Cloth presser mechanism 71 Presser foot 74 Mounting stand 100 Sewing Machine 101 Needle plate 611,611A Recess 612 Operation piece 614A Hook part 615A Through hole C Item to be sewn

Claims

1. an upper feed mechanism that feeds the workpiece from above the needle plate using a conveyor belt; a positioning ruler for positioning a side edge of the workpiece in a direction intersecting a feed direction of the workpiece; Equipped with the upper feed mechanism has the conveyor belt and the belt guide on each side of the needle drop position, A sewing machine comprising: a retraction mechanism that holds at least the conveyor belt and the belt guide on the side of the positioning ruler relative to the needle drop position at a retracted position separated from the needle drop position.

2. 2. The sewing machine according to claim 1, wherein the retraction mechanism retracts the conveyor belt and the belt guide upward.

3. The belt guide is rotatably supported by a pressing mechanism for pressing the sewing workpiece.

3. The sewing machine according to claim 1, wherein the retraction mechanism includes a holding member that holds the retracted belt guide in a retracted position by rotating the belt guide.

4. 2. The sewing machine according to claim 1, wherein the retraction mechanism includes an actuator for retracting the conveyor belt and the belt guide.

5. 2. The sewing machine according to claim 1, wherein the positioning ruler is supported by a support mechanism so as to be capable of being moved toward and away from the needle plate or the needle drop position.

6. 6. The sewing machine according to claim 5, wherein the support mechanism includes an actuator that moves the positioning ruler toward and away from the needle plate or the needle drop position.

Images