Overlock sewing machine

Abstract

An overlock sewing machine (100) comprises an adjustment input unit (34) that, when moving a needle thread adjustment unit (24) by drawing in a midway portion of a first operation wire (321), controls or reduces the interlocking of a lower looper thread adjustment unit (25) and the upper looper thread adjustment unit (26), which accompanies the movement of the needle thread adjustment unit (24) by an adjustment interlocking unit (27) and the drawing in of a midway portion of a second operation wire (331).

Description

Overedge sewing machine

[0001] The present disclosure relates to an overedge sewing machine.

[0002] Conventional overedge sewing machines feed a predetermined amount of needle thread and looper thread from a thread supply source for each stitch. This allows conventional overedge sewing machines to sew while optimizing the thread tension of each thread. Furthermore, conventional overedge sewing machines automatically adjust the thread feed amount of each thread according to the stitch pitch, overlock width, and selected stitch type, thereby optimizing the thread tension of each thread (see, for example, Patent Document 1).

[0003] Japanese Patent Application Publication No. 10-272273

[0004] The conventional sewing machines described above have a structure in which various thread payout mechanisms are interlocked, and when the amount of thread payout from the needle thread is adjusted, the amount of thread payout from the looper thread is also adjusted accordingly. In this case, the burden of adjustment work can be reduced compared to when adjusting each thread individually, and it is convenient for users. However, conventional sewing machines could not meet requests such as changing the texture of the stitches by adjusting the thread tension of only the needle thread.

[0005] An object of the present disclosure is to enable the linked adjustment of the thread payout amounts of the needle thread and the looper thread, while also adjusting the thread tension of the needle thread by suppressing fluctuations in the thread tension of the looper thread.

[0006] One aspect of the present disclosure is an overedge sewing machine comprising: a needle up-down movement mechanism for moving a sewing needle having a needle thread passed therethrough up and down; a lower looper mechanism having a lower looper for passing a lower looper thread through a loop of the needle thread; an upper looper mechanism having an upper looper for passing an upper looper thread through a loop of the lower looper thread; a feed mechanism for feeding a workpiece; and a thread reeling mechanism for reeling out the needle thread, the lower looper thread and the upper looper thread from a thread supply source in synchronization with each needle drop, wherein the thread reeling mechanism comprises: an upstream guide section having thread introduction sections for respectively passing the needle thread, the upper looper thread and the lower looper thread; a downstream guide section having thread outlet sections for respectively passing the needle thread, the upper looper thread and the lower looper thread; a pull-out section that moves back and forth between the upstream guide section and the downstream guide section in a direction intersecting the needle thread, the upper looper thread, and the lower looper thread that pass from each of the introduction section to the outlet section, thereby pulling out the needle thread, the upper looper thread, and the lower looper thread from each supply source; a needle thread adjustment section that moves between the upstream guide section and the downstream guide section in the intersecting direction, thereby varying the path of the needle thread that passes from the introduction section to the outlet section, thereby adjusting the pull-out length of the needle thread by the pull-out section; and an upper looper thread adjustment section that moves between the upstream guide section and the downstream guide section in the intersecting direction, thereby varying the path of the upper looper thread that passes from the introduction section to the outlet section, thereby adjusting the pull-out length of the upper looper thread by the pull-out section. a lower looper thread adjusting section that moves along the cross direction between the upstream guide section and the downstream guide section to vary the path of the lower looper thread from the introduction section to the withdrawal section, thereby adjusting the length of the lower looper thread pulled out by the pull-out section; a first input section that moves the needle thread adjusting section along the cross direction through a first operating wire; a second input section that moves the upper looper thread adjusting section and the lower looper thread adjusting section along the cross direction through a second operating wire; and an adjustment interlocking section that interlocks the upper looper thread adjusting section and the lower looper thread adjusting section when the needle thread adjusting section moves through the second operating wire.and an adjustment input unit that reels in an intermediate portion of the first operating wire to move the needle thread adjustment unit along the intersecting direction, wherein when the adjustment input unit reels in an intermediate portion of the first operating wire to move the needle thread adjustment unit, the adjustment input unit also reels in an intermediate portion of the second operating wire to suppress or reduce the interlocking of the lower looper thread adjustment unit and the upper looper thread adjustment unit that accompanies the movement of the needle thread adjustment unit by the adjustment interlocking unit.

[0007] With the above-described configuration, the sewing machine of the present disclosure is capable of adjusting the thread payout amounts of the needle thread and looper thread in a coordinated manner, while also being able to adjust the thread tension of the needle thread by suppressing fluctuations in the thread tension of the looper thread.

[0008] FIG. 1 is a perspective view showing an overedge sewing machine according to an embodiment of the present disclosure. FIG. 2 is a perspective view showing a thread payout mechanism. FIG. 3 is an exploded perspective view showing the thread payout mechanism. FIG. 4 is a perspective view showing the front side of two drawer plates. FIG. 5A is a perspective view showing a state before the needle thread is drawn by the drawer plates. FIG. 5B is a perspective view showing a state during the needle thread is drawn by the drawer plates. FIG. 6 is an explanatory diagram showing thread payout due to a change in thread path. FIG. 7 is a perspective view showing the front side of an upstream guide plate provided with a payout drive mechanism. FIG. 8 is a perspective view showing an upstream thread gripper and a downstream thread gripper. FIG. 9 is a perspective view showing a gripper drive mechanism. FIG. 10 is a perspective view showing an end cam. FIG. 11 is a rear view of a configuration supported on the rear side of the upstream guide plate when a twin-needle overedge stitch is selected. FIG. 12 is a rear view of a configuration supported on the rear side of the upstream guide plate when a single-needle overedge stitch is selected. Figure 13 is a rear view of the configuration supported on the rear surface of the upstream guide plate when a single-needle fine edge overlock stitch is selected. Figure 14 is a rear view of the configuration supported on the rear surface of the upstream guide plate when a single-needle wrap stitch is selected. Figure 15 is a right side view of the adjustment input unit.

[0009] [Overview of the Overlock Sewing Machine] The overlock sewing machine 100, an embodiment of the present disclosure, will be described in detail below. Hereinafter, the downstream side in the feed direction of the sewing material will be referred to as the "front," the upstream side in the feed direction as the "rear," the left-hand side when facing forward as the "left," the right-hand side as the "right," the vertically upward direction as the "up," and the vertically downward direction as the "down." These directions are relative directions set for the sewing machine 100 illustrated in FIGS. 1 to 15. The front-to-back direction, left-to-right direction, and up-to-down direction are perpendicular to one another. In the following description, it is assumed that the overlock sewing machine 100 is installed on a horizontal surface. Under this assumption, the front-to-back direction and left-to-right direction are horizontal.

[0010] FIG. 1 is a perspective view of an overlock sewing machine 100. The overlock sewing machine 100 is exemplified by a so-called overlock machine. The overlock sewing machine 100 includes a sewing machine frame 110, a needle up-and-down mechanism for moving the sewing needle up and down, a lower looper mechanism, an upper looper mechanism, a feed mechanism for feeding the sewing material, a knife mechanism, and a thread payout mechanism 2. The lower looper mechanism includes a lower looper for threading the lower looper thread through a loop of the needle thread. The upper looper mechanism includes an upper looper for threading the upper looper thread through a loop of the lower looper thread. The knife mechanism trims the side edge (e.g., the right edge) of the sewing material to trim the sewing edge. The thread payout mechanism 2 pays out the needle thread, lower looper thread, and upper looper thread from a thread supply source in synchronization with each needle entry.

[0011] The sewing machine frame 110 houses or supports the entire sewing machine. The sewing machine frame 110 has a bed portion 111 located at the bottom, a standing body portion 112 standing upright from the left side of the bed portion 111, and an arm portion 113 extending leftward from the top of the standing body portion 112. The upper left surface of the bed portion 111 is horizontal and flat. A sewing object is placed on the upper left surface of the bed portion 111, and sewing is performed. A needle plate 114 is provided on the upper left surface of the bed portion 111 in a position flush with the upper surface of the bed portion 111.

[0012] A thread stand 120 is disposed in front of the arm 113. The overedge sewing machine 100 uses up to four threads for sewing. The four threads are needle thread T1, needle thread T2, upper looper thread T3, and lower looper thread T4. The thread stand 120 has four support shafts 121-124. The support shafts 121-124 rotatably support thread spools that serve as thread supply sources for the needle thread T1, needle thread T2, upper looper thread T3, and lower looper thread T4, respectively. The support shafts 121-124 support, from left to right, the thread spools for the needle thread T1, needle thread T2, upper looper thread T3, and lower looper thread T4, respectively. In the following description, the left-hand needle thread T1 may be referred to as the left needle thread T1, and the right-hand needle thread T2 may be referred to as the right needle thread T2.

[0013] A thread guide 125 is disposed above the support shafts 121 to 124. The thread guide 125 has notched guide portions through which the left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 are inserted. The left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 are each pulled out from the thread spool, passed through the respective guide portions of the thread guide 125, and passed through four thread guide grooves 115 to 118 formed on the upper surface of the arm portion 113.

[0014] The needle up / down movement mechanism, lower looper mechanism, upper looper mechanism, feed mechanism, and knife mechanism of the overlock sewing machine 100 are the same as those well known in overlock sewing machines (lock stitch machines), and therefore detailed description will be omitted. The needle up / down movement mechanism has a needle bar that holds a sewing needle threaded therethrough at its lower end. The needle up / down movement mechanism moves the needle bar up and down to insert the needle into the workpiece on the needle plate. The needle bar is located at the bottom near the left end of the arm portion 113. The needle bar can hold one sewing needle or two sewing needles arranged side by side. This allows the overlock sewing machine 100 to perform single-needle sewing and twin-needle sewing. The left and right sewing needles are sometimes referred to as the left needle and the right needle, respectively. The sewing machine 100 can perform single-needle sewing using only the left needle and single-needle sewing using only the right needle.

[0015] The lower looper mechanism and the upper looper mechanism are disposed below the needle plate 114. The lower looper mechanism inserts the tip of the lower looper, through which the lower looper thread has been passed, into a loop of needle thread formed below the sewing object, in synchronization with the descent of the sewing needle. In the case of twin needle sewing, the tip of the lower looper is inserted into the loops of two needle threads at the same time.

[0016] The upper looper mechanism inserts the tip of the upper looper, through which the upper looper thread is threaded, into a loop of the lower looper formed below the sewing material, in synchronization with the reciprocating movement of the lower looper. The upper looper mechanism also moves the upper looper in a forward direction (forward direction) from the right end of the needle plate to above the needle plate. This allows a descending sewing needle to be inserted into the loop of the upper looper thread formed when the upper looper moves backward (rearward direction). In the case of twin-needle sewing, two descending sewing needles are simultaneously inserted into the loop of the upper looper thread.

[0017] The overedge sewing machine 100 performs overedge stitching by entangling the threads through the cooperation of the needle up / down movement mechanism, the lower looper mechanism, and the upper looper mechanism. The needle up / down movement mechanism, the lower looper mechanism, and the upper looper mechanism are all configured to receive power from the sewing machine motor via a power transmission mechanism. This allows the needle up / down movement mechanism, the lower looper mechanism, and the upper looper mechanism to be synchronized.

[0018] The feed mechanism is disposed within the bed portion 111. The feed mechanism feeds the sewing material by moving forward a feed dog that can be retracted through an opening formed in the needle plate 114. The movement of the feed dog is imparted by a transmission mechanism using the sewing machine motor as a drive source. The transmission mechanism is composed of a cam mechanism. By changing the orientation of the power transmission body included in the cam mechanism, the transmission mechanism can change the stitch pitch, which is the feed length of the feed dog (the amount of material fed per stitch). The pitch adjustment knob 131 is an input unit for setting the stitch pitch and is provided on the right side of the upright body portion 112. The orientation of the power transmission body can be changed by rotating the pitch adjustment knob 131.

[0019] The knife mechanism has a moving knife that moves up and down at the right end of the needle plate 114. The knife mechanism, in cooperation with the fixed knife, cuts off the right end of the sewing material as it passes over the needle plate 114. The moving knife is positioned behind the sewing needle and cuts off the sewing material just before a stitch is formed. The moving knife's up and down movement is also driven by the sewing machine motor. Cutting off the right end of the sewing material with the moving knife ensures that the distance from the needle point to the right end of the sewing material is a constant width. In overedge stitching, a seam is formed between the right end of the sewing material and the needle point, with the upper looper thread and the lower looper thread passing over it. The distance from the needle point to the right end of the sewing material determines the overedge width (sewing width) of the overedge stitching. The overedge width adjustment knob 132 is an input unit for setting the overedge width. The cutting position of the moving knife in the left-right direction can be adjusted by rotating the overedge width adjustment knob 132. This means that the adjustment of the cutting position by the stitch width adjustment knob 132 is the same as the setting of the stitch width.

[0020] [Outline of thread reeling mechanism] Figure 2 is a perspective view showing the thread reeling mechanism 2, and Figure 3 is an exploded perspective view showing the thread reeling mechanism 2. The thread reeling mechanism 2 has an upstream guide plate (upstream guide portion) 21, a downstream guide plate (downstream guide portion) 22, two pull-out plates (pull-out portions) 23, a needle thread adjustment plate (needle thread adjustment portion) 24, an upper looper thread adjustment plate (upper looper thread adjustment portion) 25, a lower looper thread adjustment plate (lower looper thread adjustment portion) 26, an adjustment interlocking portion 27, a stitch type selection portion 28, upstream and downstream thread gripping portions 29, a gripping drive mechanism 30, a reeling drive mechanism 31, a first input portion 32, a second input portion 33, an adjustment input portion 34, a thickness detection portion 35, and a looper thread tension setting input portion 36. Hereinafter, the upstream guide plate 21, the downstream guide plate 22, the two pull-out plates 23, the needle thread adjustment plate 24, the upper looper thread adjustment plate 25, and the lower looper thread adjustment plate 26 will be referred to as "adjustment plates" or "plates."

[0021] 3, the thread reeling mechanism 2 is arranged, from front to rear, at the upper inside portion of the arm portion 113, in the order of front to rear, including an upstream guide plate 21, a first drawer plate 23, an upper looper thread adjusting plate 25, a needle thread adjusting plate 24, a lower looper thread adjusting plate 26, a second drawer plate 23, and a downstream guide plate 22. The upstream guide plate 21, the first drawer plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, the second drawer plate 23, and the downstream guide plate 22 are all flat, and each flat surface is inclined so that it is perpendicular to the rear diagonally downward direction.

[0022] Furthermore, the first pull-out plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, and the second pull-out plate 23 each have a plurality of guide holes formed in the left-right direction at their bottom. At least two of the four support posts 215 vertically erected on the rear surface of the upstream guide plate 21 pass through these guide holes. Each support post 215 has flat upper and lower surfaces. The flat upper and lower surfaces of each support post 215 slide against the upper and lower inner edges of the guide holes of the first pull-out plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, and the second pull-out plate 23, respectively. As a result, the first pull-out plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, and the second pull-out plate 23 are all supported so as to be movable left-right relative to the upstream guide plate 21. Furthermore, spacers (not shown) through which the respective supports 215 pass are interposed between the upstream guide plate 21, the first pull-out plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, the second pull-out plate 23, and the downstream guide plate 22. These spacers form predetermined gaps between the adjacent plates 21, 23, 25, 24, 26, 23, 22 in the front and rear directions.

[0023] The downstream guide plate 22 has four insertion holes through which fastening members (not shown), such as screws, are inserted. The four insertion holes fasten and fix the tip ends of the four support posts 215 to the downstream guide plate 22. Therefore, the upstream guide plate 21, the first pull-out plate 23, the upper looper thread adjusting plate 25, the needle thread adjusting plate 24, the lower looper thread adjusting plate 26, and the second pull-out plate 23 move left and right between the upstream guide plate 21 and the downstream guide plate 22.

[0024] Four yarn introduction sections 211-214 are formed side by side in the left-right direction on the upper edge of the upstream guide plate 21. Each introduction section 211-214 is formed as a vertically long notch that opens upward on the upper edge of the upstream guide plate 21. Four yarn outlet sections 221-224 are formed side by side in the left-right direction on the upper edge of the downstream guide plate 22. Each outlet section 221-224 is also formed as a vertically long notch that opens upward on the upper edge of the downstream guide plate 22. The four introduction sections 211-214 of the upstream guide plate 21 and the four yarn outlet sections 221-224 of the downstream guide plate 22 are respectively located immediately below the four yarn guide grooves 115-118 formed on the upper surface of the arm portion 113.

[0025] Therefore, when the left needle thread T1, right needle thread T2, upper looper thread T3, and lower looper thread T4 are inserted into the four thread guide grooves 115 to 118, respectively, they enter the introduction sections 211 to 214 and the outlet sections 221 to 224. This allows the left needle thread T1 to cross from the introduction section 211 to the outlet section 221, the right needle thread T2 to cross from the introduction section 212 to the outlet section 222, the upper looper thread T3 to cross from the introduction section 213 to the outlet section 223, and the lower looper thread T4 to cross from the introduction section 214 to the outlet section 224. The threads T1 to T4 are supplied from the front side to the rear side of the upstream guide plate 21, and are consumed by sewing behind the downstream guide plate 22.

[0026] [Pull-out Plates in the Thread Payout Mechanism] The two pull-out plates 23 move back and forth between the upstream guide plate 21 and the downstream guide plate 22 along the intersecting direction relative to the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 that extend from their respective introduction sections 211-214 to their respective withdrawal sections 221-224, thereby pulling out the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 from their respective supply sources. The intersecting direction is, for example, the left-right direction, which is the perpendicular direction. The target value for the pull-out amount of each thread is equal to the length consumed by sewing each stitch. Furthermore, the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 each have a different length consumed by each stitch. For this reason, the thread paths of the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 passing between the upstream guide plate 21 and the downstream guide plate 22 are individually changed by the needle thread adjusting plate 24, the upper looper thread adjusting plate 25, and the lower looper thread adjusting plate 26. By making such changes, the amount of pulling out by the pull-out plate 23 can be adjusted.

[0027] 4 is a perspective view showing the front side of the two drawer plates 23. Both drawer plates 23 have the same shape and are long, rectangular shapes extending in the left-right direction. Each drawer plate 23 has an extension 235 extending downward from the right side of the lower edge. The two drawer plates 23 are connected by fastening members such as screws, with a spacer (not shown) inserted between each extension 235. The two drawer plates 23 are connected in a state where they overlap in the front-to-rear direction of the plate surfaces so that there is no misalignment when viewed vertically from the plate surfaces.

[0028] The extension portion 235 of the drawer plate 23 faces the upstream guide plate 21. A cylindrical roller 236 is rotatably mounted on the front side of the extension portion 235, protruding forward (strictly speaking, diagonally upward and forward). A feed-out drive mechanism 31 (details will be described later) imparts a reciprocating motion in the left-right direction to the two drawer plates 23. The roller 236 functions as a follower that fits into a cam groove 312a of a cylindrical cam 312 of the feed-out drive mechanism 31.

[0029] The pull-out plate 23 is formed with insertion sections 231 to 234. The yarns T1 to T4 that pass from the inlet sections 211 to 214 of the upstream guide plate 21 to the outlet sections 221 to 224 of the downstream guide plate 22 individually enter the insertion sections 231 to 234. Each of the insertion sections 231 to 234 is formed as a triangular notch that is open at the top. Each of the insertion sections 231 to 234 has a contact section 231a to 234a on its inner edge.

[0030] Fig. 5A is a perspective view showing a state before the needle threads T1 and T2 are pulled out by the pull-out plate 23, Fig. 5B is a perspective view showing a state during the pulling-out of the needle threads T1 and T2 by the pull-out plate, and Fig. 6 is an explanatory diagram showing thread payout due to a change in the thread path. The front pull-out plate 23 is imparted with a reciprocating motion by moving rightward and leftward relative to the upstream guide plate 21 by a pay-out drive mechanism 31, which will be described later. The rear pull-out plate 23 is imparted with a reciprocating motion by moving rightward and leftward relative to the downstream guide plate 22 by the pay-out drive mechanism 31. The rightward movement is a thread pull-out motion, and the leftward movement is a return motion of the pull-out plate 23.

[0031] In the state immediately before being pulled out as shown in Fig. 5A, the needle threads T1 and T2 have a path with a single mountain shape that is gently convex to the right, as shown by the hatched area in Fig. 6. Then, when each pull-out plate 23 moves to the right as shown in Fig. 5B, the needle threads T1 and T2 change to a path with a double mountain shape that is significantly convex to the right, as shown by the unshaded string-like shape (white line) in Fig. 6. Then, when each pull-out plate 23 moves to return to the left, the increase in the path length when the needle threads T1 and T2 are pulled out becomes the length that is let out by each pull-out plate 23. The upper looper thread T3 and the lower looper thread T4 are also let out by the same operation.

[0032] [Reel-out drive mechanism in yarn reel-out mechanism] The reel-out drive mechanism 31 will now be described. Figure 7 is a perspective view showing the front side of the upstream guide plate 21 on which the reel-out drive mechanism 31 is provided. As shown in Figure 7, the reel-out drive mechanism 31 has a drive shaft 311 rotatably supported on the front side of the upstream guide plate 21, and a cylindrical cam 312 fixed to the drive shaft 311.

[0033] The drive shaft 311 receives power from the sewing machine motor and rotates at the same cycle as the up and down movement of the sewing needles. The drive shaft 311 is arranged in the left-right direction. The cylindrical cam 312 is fixed to the drive shaft 311, which passes through the center, and rotates together with the drive shaft 311. A cam groove 312a is formed on the outer peripheral surface of the cylindrical cam 312. The upstream guide plate 21 is formed with a rectangular opening 216 that is long in the left-right direction and penetrates the upstream guide plate 21. The roller 236 of the front drawer plate 23 protrudes from the opening 216 toward the front side of the upstream guide plate 21 and fits into the cam groove 312a of the cylindrical cam 312. The cam groove 312a is shaped to move each drawer plate 23 to the right to draw the sewing needles when they are ascending, and to move each drawer plate 23 to the left when they are descending.

[0034] 3, the needle thread adjustment plate 24 is disposed between the two drawer plates 23, and has insertion portions 241, 242. Each of the insertion portions 241, 242 is a vertically long notch that is open upward at the upper edge of the needle thread adjustment plate 24. The left needle thread T1 and the right needle thread T2 enter the insertion portions 241, 242 individually from the introduction portions 211, 212 of the upstream guide plate 21 across the extraction portions 221, 222 of the downstream guide plate 22.

[0035] The upper looper thread adjusting plate 25 is disposed between the two pull-out plates 23. An insertion portion 251 is formed in the upper looper thread adjusting plate 25. The insertion portion 251 is a vertically long notch that is open upward at the upper edge of the upper looper thread adjusting plate 25. The upper looper thread T3 passes from the introduction portion 213 of the upstream guide plate 21 through the extraction portion 223 of the downstream guide plate 22 and enters the insertion portion 251.

[0036] The lower looper thread adjusting plate 26 is disposed between the two pull-out plates 23, and has an insertion portion 261 formed therein. The insertion portion 261 is a vertically long notch that is open upward at the upper edge of the lower looper thread adjusting plate 26. The lower looper thread T4 passes from the introduction portion 214 of the upstream guide plate 21 through the extraction portion 224 of the downstream guide plate 22 and enters the insertion portion 261.

[0037] The function of each adjustment plate 24-26 will be described with reference to Figures 3, 6, and 7. Here, needle threads T1 and T2 will be described as an example. The needle thread adjustment plate 24 can lock the needle threads T1 and T2 at intermediate positions along their paths using the insertion portions 241 and 242 and move them left and right. For example, if the insertion portions 241 and 242 lock the needle threads T1 and T2 at point M shown in Figure 6 and change the path so that point M moves in the opposite direction (left) from the direction of pulling out (right) using the two pull-out plates 23, the amplitude of the two peaks when the two pull-out plates 23 pull out the threads increases, allowing for more pulling out. In this way, by moving each adjustment plate 24-26 left and right, point M on each of the threads T1 to T4 can be moved left and right using the insertion portions 241, 242, 251, and 261. This allows the length of thread being fed out by the two pull-out plates 23 to be adjusted.

[0038] [Yarn gripping section in the yarn reeling mechanism] When each of the yarns T1 to T4 is reeled out by the two pull-out plates 23, it is necessary to properly pull out the yarn from the yarn supply side and not pull back the yarn from the yarn consumption side. For this reason, an upstream yarn gripping section 29 is provided on the front surface of the upstream guide plate 21, which is the yarn supply side, and a downstream yarn gripping section 29 is provided on the rear surface of the downstream guide plate 22, which is the yarn consumption side.

[0039] 8 is a perspective view showing the upstream thread gripping portion 29 and the downstream thread gripping portion 29. Since the upstream thread gripping portion 29 and the downstream thread gripping portion 29 have the same configuration, the following description will mainly focus on the downstream thread gripping portion 29.

[0040] The downstream yarn gripping section 29 has four fixed plates 291, four gripping plates 292, a support rod 293, four springs 294, and a support plate 295. The four fixed plates 291 are individually and fixedly attached to one side (e.g., the left side) of each of the outlet sections 221 to 224 on the rear surface of the downstream guide plate 22. The four gripping plates 292 are arranged opposite each of the fixed plates 291 with each of the outlet sections 221 to 224 sandwiched between them when viewed from the direction perpendicular to the plate surface of the downstream guide plate 22. The support rod 293 is arranged to pass through and support all four gripping plates 292 simultaneously. The four springs 294 are configured to individually press each of the gripping plates 292 against the side of the fixed plate 291 that the gripping plate 292 faces. The support plate 295 supports the right end of the support rod 293 and also serves as a spring support for the rightmost spring 294 .

[0041] Each fixing plate 291 is erected on the rear surface of the downstream guide plate 22 so that the surface facing the gripping plate 292 is aligned along the left inner edge of each of the lead-out sections 221 to 224. In the case of the upstream yarn gripping section 29, each fixing plate 291 is erected on the front surface of the upstream guide plate 21 so as to be aligned along the left inner edge of each of the lead-out sections 211 to 214.

[0042] The upright surface of each fixed plate 291 is perpendicular to a plane parallel to the left-right direction of the downstream guide plate 22. A through-hole is provided in the center of the surface of each fixed plate 291. The support rods 293 are simultaneously inserted through the through-holes of each fixed plate 291. Each fixed plate 291 has the function of gripping each of the yarns T1 to T4 in cooperation with the corresponding gripping plate 292, and the function of supporting the support rod 293 so that it can move left-right. Furthermore, the right end of a spring 294 that presses the adjacent gripping plate 292 on the left is pressed against each fixed plate 291. As a result, each fixed plate 291 also functions as a spring support for the spring 294.

[0043] The support plate 295 is made of the same material as the fixed plate 291, and the right end of the support rod 293 is inserted through it. The right end of the rightmost spring 294 is pressed against the support plate 295, so that the support plate 295 functions as a spring support for the rightmost spring 294. Since there is no opposing gripping plate 292, the support plate 295 does not have the function of gripping the yarn.

[0044] Each gripping plate 292 is circular. A support rod 293 passes through the center of each gripping plate 292. Each gripping plate 292 is pressed toward the fixed plate 291 by a spring 294 from the surface opposite the opposing surface of the fixed plate 291. Each spring 294 is a coil spring. A support rod 293 is inserted into the inside of each spring 294. The left end of each spring 294 presses against its respective gripping plate 292, and the right end presses against the left surface of the fixed plate 291 adjacent to it on the right. As a result, each spring 294 is supported by the fixed plate 291 adjacent to it on the right and presses each gripping plate 292 to the left.

[0045] The support rod 293 has a structure that restricts each of the gripping plates 292 from moving leftward from a predetermined support position and allows each of the gripping plates 292 to move rightward from the predetermined support position. This restricting structure is formed, for example, by an expanded diameter portion of the support rod 293 or a protruding portion of the support rod 293 that protrudes radially outward. Because the support rod 293 has the above-described restricting structure, when the support rod 293 is moved rightward, each of the gripping plates 292 can also be moved rightward. As a result, by moving the support rod 293 rightward, each of the yarns T1 to T4 gripped by each of the gripping plates 292 can be released.

[0046] [Gripping drive mechanism in yarn reeling mechanism] Figure 9 is a perspective view showing the gripping drive mechanism 30. The upstream yarn gripping section 29 and the downstream yarn gripping section 29 must grip and release each of the yarns T1 to T4 at the appropriate timing. That is, when the pull-out plate 23 is pulled out as described above, the upstream yarn gripping section 29 must be operated to be in a released state and the downstream yarn gripping section 29 must be operated to be in a gripping state, and when the pull-out plate 23 returns to its original position, the upstream yarn gripping section 29 must be operated to be in a gripping state and the downstream yarn gripping section 29 must be operated to be in a released state.

[0047] The grip drive mechanism 30 shares the drive shaft 311 of the aforementioned delivery drive mechanism 31 as its drive shaft. The grip drive mechanism 30 has an end face cam 301, an upstream follower (not shown), an upstream actuating arm 302, a downstream follower (not shown), a downstream input arm 303, and a downstream output arm 304. The end face cam 301 is provided at the left end of the drive shaft 311. The upstream follower is made of a roller that abuts on the rear area RA (see FIG. 10) of the cam surface of the end face cam 301. The upstream actuating arm 302 holds the upstream follower and performs an oscillating motion. The downstream follower is made of a roller that abuts on the front area FA (see FIG. 10) of the cam surface of the end face cam 301. The downstream input arm 303 holds the downstream follower and performs an oscillating motion. The downstream output arm 304 swings in conjunction with the downstream input arm 303, and pushes the left end of the support rod 293 of the downstream thread gripping portion 29 to the right.

[0048] FIG. 10 is a perspective view showing the end cam 301. The end cam 301 is rotated by a drive shaft 311 around an axis extending in the left-right direction. The outer periphery of the left surface of the end cam 301 forms a cam surface 301a. The cam surface 301a has left-right concave and convex portions formed at predetermined locations on the circumference. As shown in FIG. 10, the rear portion of the cam surface 301a is the rear area RA with which the upstream follower abuts. The front portion of the cam surface 301a is the front area FA with which the downstream follower abuts. This configuration of the end cam 301 allows power to be obtained at two locations 180° apart on the circumference of the single end cam 301. By obtaining this power, the upstream thread gripping portion 29 and the downstream thread gripping portion 29 can be operated alternately so that the operation timing of the upper thread gripping portion 29 and the operation timing of the lower thread gripping portion 29 are shifted by half a period based on the rotation period of the drive shaft 311.

[0049] As shown in Figure 9, the upstream operating arm 302 is swingably supported by the front end of a connecting tubular portion 305, slightly below the upper end of the upstream operating arm 302. The connecting tubular portion 305 penetrates the upstream guide plate 21 and the downstream guide plate 22, connecting the upstream guide plate 21 and the downstream guide plate 22. The connecting tubular portion 305 is fixed and faces in a direction perpendicular to the plate surface of the upstream guide plate 21 (roughly the front-to-rear direction in Figure 9). The upstream operating arm 302 slides along the outer peripheral surface of the front end of the connecting tubular portion 305, thereby performing a swinging motion.

[0050] The upstream actuating arm 302 below the connecting cylinder 305 holds the upstream follower. A left-right swing motion is input to the upstream actuating arm 302 from the end face cam 301. Furthermore, by swinging, the upstream actuating arm 302 above the connecting cylinder 305 can push the left end of the support rod 293 of the upstream thread gripping part 29 to the right of the upstream thread gripping part 29.

[0051] The connecting shaft 306 is rotatably supported inside the connecting tube portion 305. The downstream input arm 303 is fixedly connected to the front end of the connecting shaft 306 and swings together with the connecting shaft 306. The connecting shaft 306 is disposed along a direction perpendicular to the plate surface of the upstream guide plate 21 (roughly the front-to-rear direction in FIG. 9 ). The rear end of the connecting shaft 306 is fixedly connected to the lower end of the downstream output arm 304 on the rear side of the downstream guide plate 22. The downstream input arm 303 receives swinging motion in the left-right direction from the end face cam 301 via the downstream follower. The downstream output arm 304 swings together with the downstream input arm 303 via the connecting shaft 306, and can push the left end of the support rod 293 of the downstream thread gripping portion 29 toward the right of the downstream thread gripping portion 29.

[0052] The cam surface 301a of the end cam 301 is configured to push the support rod 293 of the upstream thread gripping portion 29 to the right while the sewing needle is ascending, thereby releasing the threads T1 to T4 from their gripped state. The cam surface 301a is also configured to maintain the gripped state of the threads T1 to T4 in the downstream thread gripping portion 29 while the sewing needle is descending. The cam surface 301a of the end cam 301 is also configured to push the support rod 293 of the downstream thread gripping portion 29 to the right while the sewing needle is descending, thereby releasing the threads T1 to T4 from their gripped state. The cam surface 301a is also configured to maintain the gripped state of the threads T1 to T4 in the upstream thread gripping portion 29 while the sewing needle is descending.

[0053] As a result, the gripping drive mechanism 30 can be operated in synchronization with the left and right movements of the two pull-out plates 23 so that the upstream thread gripping portion 29 is in a released state and the downstream thread gripping portion 29 is in a gripping state when the pull-out plates 23 are pulled out. Also, the gripping drive mechanism 30 can be operated in synchronization with the left and right movements of the two pull-out plates 23 so that the upstream thread gripping portion 29 is in a gripping state and the downstream thread gripping portion 29 is in a released state when the pull-out plates 23 move in the return direction.

[0054] [First Input Unit of Thread Payout Mechanism] Figure 11 is a rear view of the configuration supported on the rear side of the upstream guide plate 21 when a twin-needle overedge stitch is selected. Figure 12 is a rear view of the configuration supported on the rear side of the upstream guide plate when a single-needle overedge stitch is selected. Figure 13 is a rear view of the configuration supported on the rear side of the upstream guide plate when a single-needle thin overedge stitch is selected. Figure 14 is a rear view of the configuration supported on the rear side of the upstream guide plate when a single-needle wrap stitch is selected. The first input unit 32 is intended to link the pitch adjustment knob 131, which is an input unit for setting the stitch pitch, with the needle thread adjustment plate 24. As shown in Figures 1, 3, and 11, the first input unit 32 has a first operating wire 321, a guide pulley 322, a transmission lever 323, and a return spring 324. One end of the first operating wire 321 is connected to the pitch adjustment knob 131. The guide pulley 322 is provided on the lower rear surface of the upstream guide plate 21. The transmission lever 323 is provided on the left end of the rear surface of the upstream guide plate 21. The return spring 324 urges the transmission lever 323 to rotate in a predetermined direction (clockwise in FIG. 11 ). Although not shown, the first input unit 32 also includes a guide or pulley. The guide or pulley is arranged at various locations on the path of the first operating wire 321 from the pitch adjustment knob 131 to the guide pulley 322.

[0055] One end of the first operating wire 321 is connected to the pitch adjustment knob 131 or a member that rotates integrally with the pitch adjustment knob 131. The first operating wire 321 increases or decreases the tension in accordance with the setting input operation of the stitching pitch using the pitch adjustment knob 131, and inputs the tension to the lower end of the transmission lever 323. The other end of the first operating wire 321 extends from below, passes through the guide pulley 322, turns leftward, and is connected to the lower end of the guide pulley 322 from the right side.

[0056] The transmission lever 323 has an elongated shape extending in the vertical direction, and is rotatably supported at its vertical middle by a support shaft that is erected vertically from the upstream guide plate 21. The first operating wire 321 is connected to the lower end of the transmission lever 323 from the right side. As a result, tension is input to the transmission lever 323 from the first operating wire 321 to the right.

[0057] The transmission lever 323 has a branch 323a extending leftward from its vertically intermediate portion. One end of the aforementioned return spring 324 is connected to the branch 323a. The return spring 324 applies upward tension to the branch 323a, urging the transmission lever 323 to rotate in a direction that resists the tension that the transmission lever 323 receives from the first operating wire 321.

[0058] A pin 323b is provided at the upper end of the transmission lever 323. The pin 323b is inserted into an elongated hole provided at the lower end of the needle thread adjustment plate 24, thereby connecting the transmission lever 323 to the needle thread adjustment plate 24. As a result, when the transmission lever 323 rotates, the needle thread adjustment plate 24 moves left and right. Therefore, when the sewing pitch setting input is performed using the pitch adjustment knob 131, the needle thread adjustment plate 24 can be moved left and right via the first operating wire 321 and the transmission lever 323. In addition, the return spring 324 constantly urges the needle thread adjustment plate 24 to the right.

[0059] [Second Input Portion of Thread Payout Mechanism] The second input portion 33 is intended to link the overlock width adjustment knob 132, which is an input portion for setting the overlock width, with the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. As shown in Figures 1, 3, and 11, the second input portion 33 has a second operation wire 331, a spring 332, and a return spring 333. One end of the second operation wire 331 is connected to the overlock width adjustment knob 132, and the other end is connected to the upper looper thread adjustment plate 25. The spring 332 links the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. The return spring 333 biases the upper looper thread adjustment plate 25 to the right. Although not shown, the second input portion 33 also includes a guide or pulley. These guides or pulleys are arranged at various locations on the path of the second operating wire 331 from the stitch width adjustment knob 132 to the upper looper thread adjustment plate 25.

[0060] One end of the second operating wire 331 is connected to the overlock width adjustment knob 132 or a member that rotates integrally with the overlock width adjustment knob 132. As a result, the second operating wire 331 increases or decreases the tension in accordance with the setting input operation of the overlock width using the overlock width adjustment knob 132, and inputs it to the upper looper thread adjustment plate 25. The other end of the second operating wire 331 extends from below, turns rightward via a movable pulley 273 of the adjustment interlocking unit 27, which will be described later, and is connected to the upper looper thread adjustment plate 25 from the left side.

[0061] The spring 332 is a tension spring. The spring 332 connects the leg 252 extending downward from the lower end of the upper looper thread adjusting plate 25 and the leg 262 extending downward from the lower end of the lower looper thread adjusting plate 26. The upper looper thread adjusting plate 25 is disposed to the left of the lower looper thread adjusting plate 26. The upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are maintained in close proximity to each other by the spring 332 while maintaining this arrangement order. Furthermore, since the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are connected by the spring 332, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 can be moved in the left-right direction while, in principle, maintaining a constant distance between them.

[0062] The upper looper thread adjusting plate 25 has an arm 253 extending to the right at the right end of the upper looper thread adjusting plate 25. The left end of the above-mentioned return spring 333 is connected to the arm 253. The right end of the return spring 333 is connected to the right end of the downstream guide plate 22. The return spring 333 applies tension to the upper looper thread adjusting plate 25 via the arm 253, and applies tension in a direction that resists the leftward tension that the upper looper thread adjusting plate 25 receives from the second operating wire 331.

[0063] [Adjustment interlocking unit in thread reeling mechanism] The adjustment interlocking unit 27 is intended to interlock the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 through the second operating wire 331 when the needle thread adjusting plate 24 moves. As shown in Figures 3 and 11 , the adjustment interlocking unit 27 has an interlocking plate 271, a connecting link 272, and a movable pulley 273. The interlocking plate 271 moves left and right in conjunction with the rotation of the transmission lever 323 of the first input unit 32. The connecting link 272 connects the transmission lever 323 and the interlocking plate 271. The movable pulley 273 is disposed in a cam hole 271a of the interlocking plate 271.

[0064] The interlocking plate 271 has two elongated holes at its upper end. Of the four support posts 215 erected rearward from the upstream guide plate 21, the left two are inserted into the two elongated holes, respectively. The interlocking plate 271 is supported so as to be movable in the left-right direction and is disposed between the front drawer plate 23 and the needle thread adjustment plate 24. The interlocking plate 271 has a downward extension extending downward from the lower right side, and an arm extending leftward from the left edge of the downward extension. The right end of a connecting link 272 is rotatably connected to the arm. The left end of the connecting link 272 is rotatably connected to the right corner near the upper end of the transmission lever 323 of the first input unit 32. As a result, when the transmission lever 323 of the first input unit 32 rotates, the needle thread adjustment plate 24 and the interlocking plate 271 can be moved in the same direction.

[0065] Furthermore, a cam hole 271a is formed in the downward extending portion of the interlocking plate 271, penetrating the interlocking plate 271 in the front-to-rear direction. This cam hole 271a has a certain length in the up-down direction and a certain width in the left-to-right direction. The rotation shaft of a movable pulley 273 passes through the cam hole 271a from front to rear. The movable pulley 273 is disposed on the rear side of the interlocking plate 271. The movable pulley 273 mainly moves up and down, and can also move slightly back and forth, within the range allowed by the cam hole 271a. The rotation shaft of the movable pulley 273 is supported on the front side of the interlocking plate 271 by the upper end of a tip link 284 of the stitch type selection unit 28, which will be described later.

[0066] As described above, the second operation wire 331 extending from below is hung over the movable pulley 273. The second operation wire 331 is turned to the right by the movable pulley 273 and connected to the upper looper thread adjusting plate 25 from the left. Therefore, when the interlocking plate 271 moves to the left together with the needle thread adjusting plate 24, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 connected by the spring 332 can be moved to the left while interlocking with each other via the movable pulley 273 and the second operation wire 331. Furthermore, when the interlocking plate 271 moves to the right together with the needle thread adjusting plate 24, slack is generated in the second operation wire 331, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 can be moved to the right while interlocking with each other due to the tension of the return spring 333.

[0067] [Stitch type selection unit in thread reeling mechanism] The thread reeling mechanism 2 has a stitch type selection unit 28. When a stitch type is selected, the stitch type selection unit 28 adjusts the thread reeling amount of each of the threads T1 to T4 individually according to the selected stitch type. The stitch types that can be selected by the stitch type selection unit 28 are (1) twin-needle overedge stitch (twin-needle lock stitch), (2) single-needle overedge stitch (single-needle lock stitch), (3) single-needle fine overedge stitch (single-needle fine lock stitch), and (4) single-needle wrap stitch (single-needle wrap stitch).

[0068] As shown in Figure 11, the stitch type selection unit 28 has a cam plate 281, a stitch type switching knob 282, a base end link 283 and a tip end link 284, a spacing member 285, a base end link 286 and a tip end link 287, and a lock spring 288. The stitch type switching knob 282 moves the cam plate 281 in the left-right direction. The base end link 283 and the tip end link 284 support the movable pulley 273 described above. The spacing member 285 moves the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 apart. The base end link 286 and the tip end link 287 support the spacing member 285. The lock spring 288 holds the cam plate 281 at four positions in the left-right direction.

[0069] The cam plate 281 is a long, flat plate that is long in the left-right direction, and has four openings lined up in the left-right direction. The first and third openings from the left of the cam plate 281 are linear along the left-right direction. These first and third openings are support holes. Specifically, support posts erected on the rear surface of the upstream guide plate 21 are inserted into the first and third support holes, thereby supporting the cam plate 281. The cam plate 281 is supported by the upstream guide plate 21 by these two support holes so that it can slide left-right.

[0070] The second and fourth openings from the left of the cam plate 281 are cam holes 281a and 281b. The cam holes 281a and 281b are involved in the movement of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26. The functions of these cam holes 281a and 281b will be described later.

[0071] The stitch type switching knob 282 is cylindrical and supported by the upstream guide plate 21 so as to be rotatable about an axis extending in the left-right direction. The stitch type switching knob 282 is disposed so that its outer peripheral surface closely faces the front surface of the right end of the cam plate 281. A spiral cam groove 282a (see FIG. 12) is formed on the outer peripheral surface of the stitch type switching knob 282. A pin 281c that fits into the spiral cam groove 282a is provided facing forward on the front surface of the right end of the cam plate 281 that faces the stitch type switching knob 282. Therefore, when the stitch type switching knob 282 is rotated, the pin 281c is guided into the spiral cam groove 282a, and the cam plate 281 can be moved in the left-right direction.

[0072] Furthermore, four wedge-shaped notches 281d are formed in a row at the lower end of the cam plate 281. Furthermore, the lock spring 288 is a plate spring with a wedge-shaped protrusion at its tip. The lock spring 288 is supported on the lower part of the rear surface of the upstream guide plate 21. The tip of the lock spring 288 fits into one of the four notches 281d depending on the position of the cam plate 281. In other words, the four notches 281d are arranged so that the cam plate 281 can be positioned depending on each of the four stitch types selected along the stitch type selection unit 28, and the lock spring 288 can hold the cam plate 281 in each position.

[0073] The base end link 283 supporting the movable pulley 273 and the tip link 284 are rotatably connected to each other. The base end of the base end link 283 is rotatably supported by the left support pillar supporting the cam plate 281. As described above, the tip end of the tip link 284 supports the movable pulley 273 via the cam hole 271a of the interlocking plate 271. Furthermore, a pin 283a protruding rearward is provided at the connection between the base end link 283 and the tip link 284. The pin 283a is fitted into the cam hole 281a on the left side of the cam plate 281. In this configuration, the pin 283a moves up and down in response to the left-right movement of the cam plate 281. The up and down movement of the pin 283a also moves the movable pulley 273 up and down via the tip link 284.

[0074] The spacing member 285 is supported at the tip portions of the base end link 286 and the tip end link 287 in a state where it is interposed between the leg portion 252 of the upper looper thread adjusting plate 25 and the leg portion 262 of the lower looper thread adjusting plate 26, which are adjacent to each other. The spacing member 285 is cylindrical. By moving the spacing member 285 upward, the leg portion 252 and the leg portion 262 can be separated to the left and right so as to be pushed apart.

[0075] The tip of the tip link 287 supports the separation member 285. Furthermore, a pin 286a that protrudes rearward is provided at the connection between the base end link 286 and the tip link 287. The pin 286a is fitted into a cam hole 281b on the right side of the cam plate 281. In this configuration, the pin 286a moves up and down in response to the left-right movement of the cam plate 281. The up and down movement of the pin 286a causes the separation member 285 to also move up and down via the tip link 287.

[0076] The following describes changes in the payout amounts of the threads T1 to T4 depending on the stitch type selected in the stitch type selection unit 28. Figure 11 shows the operating state of the stitch type selection unit 28 when (1) a twin-needle overedge stitch (twin-needle lock stitch) is selected. Figure 12 shows the operating state of the stitch type selection unit 28 when (2) a single-needle overedge stitch (single-needle lock stitch) is selected. Figure 13 shows the operating state of the stitch type selection unit 28 when (3) a single-needle fine overedge stitch (single-needle fine lock stitch) is selected. Figure 14 shows the operating state of the stitch type selection unit 28 when (4) a single-needle wrap stitch (single-needle wrap stitch) is selected. The following description will be given assuming that the operating state of the stitch type selection unit 28 when (1) a twin-needle overedge stitch (twin-needle lock stitch) in Figure 11 is selected is a state in which the threads T1 to T4 are paid out at the reference value.

[0077] In the case of (1) twin-needle overedge stitching shown in Figure 11, the cam plate 281 is positioned at the leftmost position by operating the stitch type changeover knob 282. In this case, the pin 283a is positioned at the topmost position within the left cam hole 281a. The height of the pin 283a can be changed in three stages within the cam hole 281a: "upper," "middle," and "lower" (the height of the movable pulley 273 also changes in the same way). In Figure 11, the pin 283a and the movable pulley 273 are positioned at the "upper" position.

[0078] Meanwhile, in the right cam hole 281b, the pin 286a is at the lowest position. The height of the pin 286a changes in two stages, "up" and "down," in the cam hole 281b (the height of the separation member 285 also changes in the same way). In Figure 11, the pin 286a and the separation member 285 are in the "down" position.

[0079] In the case of single-needle overedge stitching (2) shown in Figure 12, the left needle is removed and the left needle thread T1 is not used. Then, by operating the stitch type switching knob 282, the cam plate 281 moves to the second position from the left. In this case, the pin 283a moves down within the left cam hole 281a, and the pin 283a and the movable pulley 273 are positioned at the "middle" height. The lowering of the movable pulley 273 causes slack in the second operating wire 331, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are pulled by the return spring 333 and move to the right. In this case, the payout amounts of the upper looper thread T3 and the lower looper thread T4 are reduced from the reference amounts. In this case, the needle thread adjusting plate 24 does not move, so the right needle thread T2 maintains the reference payout amount. In the case of single-needle overedge stitching, which does not use the left sewing needle, the width of the stitch from left to right is narrower than in twin-needle overedge stitching, so the consumption of upper looper thread T3 and lower looper thread T4 is reduced.

[0080] On the other hand, in the right cam hole 281b, the pin 286a and the separating member 285 maintain the "down" height position because in the case of single-needle overedge stitching, the relative consumption ratio of the upper looper thread T3 and the lower looper thread T4 does not change.

[0081] In the case of (3) single-needle fine overlock stitch (single-needle fine lock stitch) shown in Figure 13, the left sewing needle is removed and the left needle thread T1 is not used. Then, by operating the stitch type changeover knob 282, the cam plate 281 moves to the third position from the left. In this case, the pin 283a moves down within the left cam hole 281a, and the pin 283a and the movable pulley 273 are positioned at the "down" height. The lowering of the movable pulley 273 causes slack in the second operating wire 331, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are pulled by the return spring 333 and move to the right. In this case, the payout amounts of the upper looper thread T3 and the lower looper thread T4 are further reduced compared to the case of Figure 12. In the case of single-needle narrow edge overlock stitching, the width of the overlock on the left and right sides of the stitch is narrower than in the case of single-needle narrow edge overlock stitching, so the consumption of the upper looper thread T3 and the lower looper thread T4 is further reduced.

[0082] On the other hand, in the right cam hole 281b, the pin 286a and the separating member 285 maintain the "down" height position because in the case of single-needle fine edge overlock stitching, the relative consumption ratio of the upper looper thread T3 and the lower looper thread T4 does not change.

[0083] In the case of (4) single-needle overlock stitching (single-needle overlock stitching) shown in Figure 14, the left sewing needle is removed and the left needle thread T1 is not used. In addition, in the case of overlock stitching, the right edge of the sewing material is folded to the left at a specified width and overlapped (wound), and then the overlock stitch is performed. For this reason, a dedicated presser foot is used for overlock stitching. As shown in Figure 14, by operating the stitch type switching knob 282, the cam plate 281 moves to the rightmost position. In this case, the pin 283a rises within the left cam hole 281a, and the pin 283a and the movable pulley 273 are positioned at the "middle" height. The rise of the movable pulley 273 generates tension in the second operating wire 331, and the upper looper thread adjusting plate 25 moves further to the left than in the case of (3) single-needle narrow edge overlock stitching.

[0084] Meanwhile, in the right cam hole 281b, the pin 286a and the separating member 285 rise to the "up" height position. As a result, the upper looper thread adjusting plate 25 moves to the left and the lower looper thread adjusting plate 26 moves to the right, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are separated from each other to the left and right. In addition, the lower looper thread adjusting plate 26 moves to the right, and the amount of lower looper thread T4 that is paid out decreases. This is because, in the case of single-needle wrap stitching, a stitch is formed so as to wrap around the right end of the overlapping sewn material with the upper looper thread T3, and therefore the upper looper thread T3 is consumed in greater amount than the lower looper thread T4.

[0085] [Thickness Detection Unit] The purpose of the thickness detection unit 35 is to adjust the amount of each of the threads T1 to T4 to be fed in accordance with the thickness of the material to be sewn on the needle plate 114. As shown in FIG. 2, the thickness detection unit 35 includes a thickness detection lever 351, a support link 352, and a pulley 353. The thickness detection lever 351 is a thickness detection member. The thickness detection lever 351 rotates in conjunction with the up and down movement of a presser foot (not shown) that presses down on the material to be sewn on the needle plate 114 from above. The support link 352 rotates together with the thickness detection lever 351. The pulley 353 is rotatably supported at the rotating end of the support link 352.

[0086] The thickness detection lever 351 is biased by a spring (not shown) so that the left end of the thickness detection lever 351 rotates downward. When the thickness of the material on the needle plate increases, the left end of the thickness detection lever 351 rotates upward against the force of the spring. The support link 352 supports the pulley 353 at its lower end and rotates in the same direction as the thickness detection lever 351. In other words, when the left end of the thickness detection lever 351 rotates upward, the lower end of the support link 352 rotates leftward. The pulley 353 is positioned so as to abut, from the right side, against the middle portion of the first operating wire 321 that extends from the bottom (pitch adjustment knob 131) to the guide pulley 322 of the first input portion 32.

[0087] With the above configuration, as the material to be sewn becomes thicker, the pulley 353 moves to the left, and the intermediate portion of the first operation wire 321 that reaches the guide pulley 322 of the first input portion 32 from below is pulled to the left by the pulley 353 abutting from the right side. As a result, the tension of the first operation wire 321 increases, causing the transmission lever 323 of the first input portion 32 to rotate and move the needle thread adjustment plate 24 to the left. Furthermore, when the transmission lever 323 rotates, the adjustment interlocking portion 27 moves the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 to the left. Therefore, as the material to be sewn becomes thicker, adjustment can be made to increase the payout amount of each of the threads T1 to T4, and as the material to be sewn becomes thinner, adjustment can be made to decrease the payout amount of each of the threads T1 to T4.

[0088] [Looper thread tension setting input section] The looper thread tension setting input section 36 is a means for adjusting the thread tension of the upper looper thread T3 and the thread tension of the lower looper thread T4 so that they can be increased or decreased as desired by adjusting the thread payout amount by the thread payout mechanism 2. The looper thread tension setting input section 36 has a looper thread tension adjustment knob 361, a support link 362, and two pulleys 363 and 364. The looper thread tension adjustment knob 361 is a setting input section for inputting settings for the thread tension of the upper looper thread T3 and the thread tension of the lower looper thread T4. The support link 362 rotates in conjunction with the rotational adjustment operation of the looper thread tension adjustment knob 361. The two pulleys 363 and 364 are provided at the base end and the rotating end of the support link 362, respectively.

[0089] The looper thread tension adjustment knob 361 is rotated to input an increase or decrease in the thread tension of the upper looper thread T3 and an increase or decrease in the thread tension of the lower looper thread T4. The looper thread tension adjustment knob 361 is provided with a mechanism for holding the position after rotation, for example, by a latch mechanism (not shown). The support link 362 is rotatably supported at its lower end, and its upper end rotates. The upper end of the support link 362 is connected to the looper thread tension adjustment knob 361 or to a member that rotates integrally with the looper thread tension adjustment knob 361. This connection allows the upper end of the support link 362 to rotate in the same direction as the rotation of the looper thread tension adjustment knob 361 in conjunction with the looper thread tension adjustment knob 361.

[0090] The pulley 363 is provided at the lower end of the support link 362. The pulley 363 is arranged so as to abut, for example, from the left side, against the middle portion of the second operation wire 331 that extends from the bottom (the overlock width adjustment knob 132) to the movable pulley 273 of the adjustment interlocking part 27. The pulley 364 is provided at the upper end of the support link 362. The pulley 364 is arranged just above the pulley 363 so as to abut, for example, from the right side, against the middle portion of the second operation wire 331.

[0091] 2, the upper pulley 364 comes into contact with the middle portion of the second operating wire 331 from the right side relative to the lower pulley 363, and the middle portion of the second operating wire 331 is pulled to the left. As a result, the second operating wire 331 generates tension, which moves the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 to the left. This increases the amount of payout of the upper looper thread T3 and the lower looper thread T4, and reduces the thread tension of the upper looper thread T3 and the lower looper thread T4 during sewing.

[0092] 2, the upper pulley 364 moves to the right relative to the lower pulley 363 at the midpoint of the second operating wire 331, reducing the amount of pulling in of the second operating wire 331. As a result, the tension of the second operating wire 331 decreases, causing the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 to move to the right. This reduces the amount of payout of the upper looper thread T3 and the lower looper thread T4, and increases the thread tension of the upper looper thread T3 and the lower looper thread T4 during sewing.

[0093] In this way, the looper thread tension setting input unit 36 ​​can adjust the thread tension of the upper looper thread T3 and the lower looper thread T4 to increase or decrease as desired without moving the needle thread adjusting plate 24.

[0094] [Adjustment input unit] The adjustment input unit 34 aims to adjust the thread tension of the needle threads T1 and T2 by pulling on the middle part of the first operating wire 321 to move the needle thread adjustment plate 24, and to also pull on the middle part of the second operating wire 331, thereby preventing or reducing the linkage of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 that accompanies the movement of the needle thread adjustment plate 24 by the adjustment linkage unit 27.

[0095] 15 is a right side view of the adjustment input unit 34. As shown in FIGS. 2 and 15 , the adjustment input unit 34 is disposed below the upstream guide plate 21. The adjustment input unit 34 manually pulls on a midpoint of the first operation wire 321 extending from the bottom (pitch adjustment knob 131) to the guide pulley 322 of the first input unit 32, and a midpoint of the second operation wire 331 extending from the bottom (overlock width adjustment knob 132) to the movable pulley 273 of the adjustment interlocking unit 27, thereby adjusting the thread tension of the needle threads T1 and T2.

[0096] The adjustment input unit 34 has a pair of first abutment pulleys 341, a pair of second abutment pulleys 342, a first pull-out pulley 343, a second pull-out pulley 344, a support link 345, a support bracket 346, a lever member 347, and a needle thread tension adjustment knob 348. Each of the pair of first abutment pulleys 341 abuts against a middle portion of the first operation wire 321 from one side (e.g., the rear side). Each of the pair of second abutment pulleys 342 abuts against a middle portion of the second operation wire 331 from one side (e.g., the rear side). The first pull-out pulley 343 winds half of the loop of the first operation wire 321 pulled out from between the pair of first abutment pulleys 341. The second pull-out pulley 344 winds half of the loop of the second operation wire 331 pulled out from between the pair of second abutment pulleys 342. The support link 345 supports the first drawer pulley 343 and the second drawer pulley 344. The support bracket 346 rotatably supports the support link 345 by a support shaft 346a. The lever member 347 inputs a rotational motion to the support link 345. The needle thread tension adjustment knob 348 is provided on the rear cover of the overedge sewing machine 100 so as to be movable up and down.

[0097] The pair of first abutment pulleys 341 are arranged vertically at a fixed interval. The first operation wire 321 is pulled out in a loop from between the two first abutment pulleys 341 toward the rear, bypassing the pair of first abutment pulleys 341. A first pull-out pulley 343 is arranged behind the pair of first abutment pulleys 341. The loop-shaped first operation wire 321 is half-wound around a range that is approximately halfway around the rear side of the first pull-out pulley 343. In this state, if the first pull-out pulley 343 moves rearward, the first operation wire 321 is pulled out excessively, and the tension of the first operation wire 321 increases on the downstream side of the first operation wire 321. Furthermore, if the first pull-out pulley 343 moves forward, the amount of pull-out of the first operation wire 321 decreases, and the tension of the first operation wire 321 also decreases on the downstream side of the first operation wire 321.

[0098] The pair of second abutment pulleys 342 are arranged vertically at a fixed interval. The second operation wire 331 is pulled out in a loop from between the two second abutment pulleys 342 toward the rear, bypassing the pair of second abutment pulleys 342. The second pull-out pulley 344 is arranged behind the pair of second abutment pulleys 342. The loop-shaped second operation wire 331 is wound halfway around a range that is approximately halfway around the rear side of the second pull-out pulley 344. In this state, if the second pull-out pulley 344 moves rearward, the second operation wire 331 is pulled out excessively, and the tension of the second operation wire 331 increases on the downstream side of the second operation wire 331. On the other hand, if the second pull-out pulley 344 moves forward, the amount of pull-out of the second operation wire 331 decreases, and the tension of the second operation wire 331 also decreases on the downstream side of the second operation wire 331.

[0099] The first abutment pulley 341 and the second abutment pulley 342 are rotatably supported by a support bracket 346 via a shaft extending in the left-right direction. The first pullout pulley 343 and the second pullout pulley 344 are rotatably supported by a support link 345 and a shaft extending in the left-right direction. The support link 345 is generally elongated in the vertical direction. The support link 345 supports the second pullout pulley 344 at its upper end and the first pullout pulley 343 at its middle portion. Furthermore, the support link 345 is rotatably supported by the support bracket 346 via a support shaft 346a extending in the left-right direction between the first pullout pulley 343 and the second pullout pulley 344. Furthermore, the support link 345 is disposed rearward of the pair of first abutment pulleys 341 and the pair of second abutment pulleys 342 supported by the support bracket 346.

[0100] In this configuration, for example, when the support link 345 rotates clockwise in Fig. 15 , the first pulley 343 moves away from the pair of first abutment pulleys 341, and the second pulley 344 moves closer to the pair of second abutment pulleys 342, as indicated by the two hollow arrows. That is, the tension in the first operation wire 321 increases, and the tension in the second operation wire 331 decreases. Also, when the support link 345 rotates counterclockwise in Fig. 15 , the first pulley 343 moves closer to the pair of first abutment pulleys 341, and the second pulley 344 moves away from the pair of second abutment pulleys 342, as indicated by the two black arrows. That is, the tension in the first operation wire 321 decreases, and the tension in the second operation wire 331 increases.

[0101] In other words, when the support link 345 is rotated clockwise, the first drawer pulley 343 moves away from the first operation wire 321, increasing the tension and moving the needle thread adjusting plate 24 to the left. Furthermore, in response to this, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 move to the left by the adjustment interlocking part 27. However, the clockwise rotation of the support link 345 causes the second drawer pulley 344 to move closer to the first operation wire 321, reducing the tension of the second operation wire 331 and causing the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 to move to the right, thereby preventing or reducing the left-right movement of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26.

[0102] Furthermore, when the support link 345 is rotated counterclockwise, the first drawer pulley 343 moves closer to the first operation wire 321, reducing the tension, and the needle thread adjusting plate 24 moves to the right. Furthermore, accompanying this, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 move to the right by the adjustment interlocking part 27. However, since the second drawer pulley 344 moves away from the first operation wire 321 due to the counterclockwise rotation of the support link 345, the tension of the second operation wire 331 increases, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 move to the left, so that the left-right movement of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 is suppressed or reduced.

[0103] The pivoting operation of the support link 345 described above is performed from the needle thread tension adjustment knob 348 through the lever member 347. The lever member 347 is pivotable by a shaft 347a that extends in the left-right direction. The pivoting end of the lever member 347 extends rearward from the shaft 347a. An engagement protrusion 347b that protrudes to the right is provided on the lower side of the shaft 347a. The engagement protrusion 347b is loosely inserted into an engagement hole 345a provided in the lower end of the support link 345. The pivoting end of the lever member 347 has a spherically expanded tip, and is inserted into the needle thread tension adjustment knob 348. The inner bottom of the needle thread tension adjustment knob 348 is a spherical concave surface that can slide on the spherical pivoting end of the lever member 347. Therefore, when the needle thread tension adjusting knob 348 is operated up and down, the spherical rotating end of the lever member 347 and the inner bottom surface of the needle thread tension adjusting knob 348 slide against each other, and the lever member 347 can be rotated.

[0104] When the lever member 347 rotates, the engaging protrusion 347b moves around the shaft portion 347a, causing the support link 345 to rotate via the engaging hole 345a. The lever member 347 and the support link 345 have significantly different rotation radii. However, the engaging hole 345a is an elongated hole that extends along the radial direction of the support link 345. Therefore, the difference in rotation radii between the lever member 347 and the support link 345 is tolerated, and the rotational motion can be transmitted from the lever member 347 to the support link 345.

[0105] [Operation of Overedge Sewing Machine] The operation of the overedge sewing machine 100 regarding the feeding of the threads T1 to T4 will be described below.

[0106] In the overedge sewing machine 100 configured as described above, when the pitch adjustment knob 131 is rotated in the direction in which the stitching pitch increases, the tension of the first operating wire 321 increases, causing the needle thread adjustment plate 24 to move to the left. In addition, the adjustment interlocking part 27 also causes the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 to move in the same direction as the needle thread adjustment plate 24. This increases the amount of needle threads T1, T2, upper looper thread T3, and lower looper thread T4 that are fed out, thereby making it possible to accommodate the increase in stitching pitch.

[0107] Furthermore, when the pitch adjustment knob 131 is rotated in a direction that decreases the stitching pitch, the tension of the first operating wire 321 decreases, moving the needle thread adjusting plate 24 to the right. Furthermore, the adjustment interlocking part 27 also moves the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 in the same direction as the needle thread adjusting plate 24. This reduces the amount of needle threads T1, T2, upper looper thread T3, and lower looper thread T4 that are fed out, thereby corresponding to the decrease in stitching pitch.

[0108] Furthermore, when the overlock width adjustment knob 132 is rotated in the direction in which the overlock width increases, the tension of the second operating wire 331 increases, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 move to the left. This increases the amount of payout of the upper looper thread T3 and the lower looper thread T4, thereby corresponding to the increase in the overlock width.

[0109] Furthermore, when the overlock width adjustment knob 132 is rotated in a direction that reduces the overlock width, the tension of the second operating wire 331 is reduced, and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 move to the right. This reduces the amount of payout of the upper looper thread T3 and the lower looper thread T4, allowing for the reduction in the overlock width.

[0110] In addition, when the thickness of the material to be sewn on the needle plate 114 increases, the thickness detection lever 351 of the thickness detection unit 35 rotates, the tension of the first operating wire 321 that is being pulled by hand increases, the needle thread adjustment plate 24, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the left, and the amount of needle threads T1, T2, upper looper thread T3 and lower looper thread T4 that are paid out increases, allowing the material to be sewn with a greater thickness to be accommodated.

[0111] In addition, when the thickness of the material to be sewn on the needle plate 114 becomes thinner, the thickness detection lever 351 of the thickness detection unit 35 rotates, the tension of the first operating wire 321 that was being pulled by hand is reduced, and the needle thread adjustment plate 24, upper looper thread adjustment plate 25 and lower looper thread adjustment plate 26 move to the right, reducing the amount of needle threads T1, T2, upper looper thread T3 and lower looper thread T4 that are paid out, allowing the material to be sewn with a thinner thickness.

[0112] In addition, when the looper thread tension adjustment knob 361 of the looper thread tension setting input section 36 is operated in a direction that decreases the thread tension of each looper thread T3, T4, the tension of the second operating wire 331 that is being pulled by hand increases, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the left, the amount of upper looper thread T3 and lower looper thread T4 that is let out increases, and the thread tension of the stitches can be reduced.

[0113] In addition, when the looper thread tension adjustment knob 361 is operated in a direction that increases the thread tension of each looper thread T3, T4, the tension of the second operating wire 331 that is being pulled by hand is reduced, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the right, the amount of upper looper thread T3 and lower looper thread T4 that is let out is reduced, and the thread tension of the stitches can be increased.

[0114] Furthermore, if it is desired to reduce the thread tension of the needle threads T1 and T2 without changing the thread tension of the looper threads T3 and T4, the needle thread tension adjustment knob 348 of the adjustment input unit 34 is operated upward. This increases the tension of the first operation wire 321, which has been reeled in, and reduces the tension of the second operation wire 331. Accordingly, the needle thread adjustment plate 24 moves to the left. The upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 then move leftward in conjunction with each other, but the reduction in the tension of the second operation wire 331 offsets the leftward movements of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. As a result, fluctuations in the payout amounts of the upper looper thread T3 and the lower looper thread T4 are suppressed, and the payout amounts of the needle threads T1 and T2 increase, making it possible to reduce the thread tension of the needle threads T1 and T2 alone.

[0115] Furthermore, if it is desired to increase the thread tension of the needle threads T1 and T2 without changing the thread tension of the looper threads T3 and T4, the needle thread tension adjustment knob 348 of the adjustment input unit 34 is operated downward. This reduces the tension of the first operation wire 321, which has been reeled in, and increases the tension of the second operation wire 331. Accordingly, the needle thread adjustment plate 24 moves to the right. The upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 then move rightward in conjunction with each other, but the increased tension of the second operation wire 331 offsets the rightward movements of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. This suppresses fluctuations in the payout amounts of the upper looper thread T3 and the lower looper thread T4, reduces the payout amounts of the needle threads T1 and T2, and allows the thread tension of the needle threads T1 and T2 to be increased.

[0116] [Technical Effects of the Overlock Sewing Machine] The overlock sewing machine 100 is provided with an adjustment input unit 34 that, when the needle thread adjustment plate 24 is moved by reeling in a midpoint of the first operating wire 321, also reeling in a midpoint of the second operating wire 331, thereby suppressing or reducing the interlocking of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 that accompanies the movement of the needle thread adjustment plate 24 by the adjustment interlocking unit 27. This makes it possible to suppress fluctuations in the tension of the upper looper thread T3 and the lower looper thread T4 and to adjust the thread tension of only the needle threads T1 and T2, thereby enabling a wider variety of sewing to be performed with high stitch quality.

[0117] Furthermore, the overedge sewing machine 100 can be configured such that the first input unit 32 includes a pitch adjustment knob 131. This makes it possible to optimize the payout amount and thread tension of each of the threads T1 to T4 through the first operating wire 321 in accordance with an increase or decrease in the stitching pitch.

[0118] Furthermore, the overedge sewing machine 100 can be configured such that the second input section 33 includes an overedge width adjustment knob 132. This makes it possible to optimize the payout amounts and thread tensions of the looper threads T3 and T4 through the second operating wire 331 in accordance with an increase or decrease in the overedge width.

[0119] The overedge sewing machine 100 also has a stitch type selection unit 28 that, when a stitch type is selected, adjusts the thread payout amounts of the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 to the thread payout amounts appropriate to the selected stitch type. This allows each of the threads T1 to T4 to be paid out appropriately for a plurality of stitch types, making it possible to sew a wider variety of stitches with high stitch quality.

[0120] In addition, the overedge sewing machine 100 has a thickness detection unit 35 that adjusts the amount of thread let-out for each of the needle threads T1, T2, upper looper thread T3 and lower looper thread T4 according to the thickness of the material being sewn. This allows each thread T1 to T4 to be let out appropriately according to the thickness of the material being sewn, making it possible to sew with high stitching quality according to the thickness of the material being sewn.

[0121] In addition, the overedge sewing machine 100 has a looper thread tension setting input unit 36 ​​that adjusts the thread tension of the upper looper thread T3 and the lower looper thread T4, so that fluctuations in the thread tension of the left and right needle threads T1, T2 can be suppressed and the thread tension of the upper looper thread T3 and the lower looper thread T4 can be adjusted exclusively, making it possible to perform a wider variety of sewing with high sewing quality.

[0122] [Others] The above describes the embodiments of the present disclosure. However, the present disclosure is not limited to the above embodiments. For example, in the embodiments, a component integrally formed from a single member may be replaced with a component divided into multiple members that are connected or fixed to each other. Furthermore, a component formed by connecting multiple members may be replaced with a component integrally formed from a single member. In addition, the details shown in the embodiments may be modified as appropriate without departing from the spirit of the invention.

[0123] For example, the arrangement of the pulleys 341 to 344 of the adjustment input unit 34 is not limited to the above example. The arrangement of the pulleys can be arbitrarily changed as long as the same effect as that of the adjustment input unit described above can be obtained. In the above embodiment, the pull-out direction of the first pull-out pulley 343 relative to the first abutment pulley 341 and the pull-out direction of the second pull-out pulley 344 relative to the second abutment pulley 342 are substantially the same. However, for example, if these pull-out directions are opposite to each other, the first pull-out pulley 343 and the second pull-out pulley 344 do not need to be arranged with the support shaft 346a of the support link 345 sandwiched between them. In this case, it is preferable to arrange the first pull-out pulley 343 and the second pull-out pulley 344 on the same side of the support shaft 346a of the support link 345. Furthermore, the support link 345 may not be rotatable. Specifically, the first pullout pulley 343 and the second pullout pulley 344 may be configured to move toward and away from the first contact pulley 341 and the second contact pulley 342 in a linear motion.

[0124] The present disclosure includes the following aspects: (1) An overedge sewing machine comprising: a needle up-down movement mechanism for moving a sewing needle having a needle thread threaded therethrough up and down, a lower looper mechanism having a lower looper for passing a lower looper thread through a loop of the needle thread, an upper looper mechanism having an upper looper for passing an upper looper thread through a loop of the lower looper thread, a feed mechanism for feeding a workpiece, and a thread reeling mechanism for reeling out the needle thread, the lower looper thread, and the upper looper thread from a thread supply source in synchronization with each needle drop, wherein the thread reeling mechanism comprises: an upstream guide section having thread introduction sections for each of the needle thread, the upper looper thread, and the lower looper thread, and a downstream guide section having thread introduction sections for each of the needle thread, the upper looper thread, and the lower looper thread, a pull-out section that moves back and forth between the upstream guide section and the downstream guide section in a direction intersecting the needle thread, the upper looper thread, and the lower looper thread that pass from each of the introduction section to the outlet section, thereby pulling out the needle thread, the upper looper thread, and the lower looper thread from each supply source; a needle thread adjustment section that moves between the upstream guide section and the downstream guide section in the intersecting direction, thereby varying the path of the needle thread that passes from the introduction section to the outlet section, thereby adjusting the pull-out length of the needle thread by the pull-out section; and an upper looper thread adjustment section that moves between the upstream guide section and the downstream guide section in the intersecting direction, thereby varying the path of the upper looper thread that passes from the introduction section to the outlet section, thereby adjusting the pull-out length of the upper looper thread by the pull-out section. a lower looper thread adjusting section that moves along the cross direction between the upstream guide section and the downstream guide section to vary the path of the lower looper thread from the introduction section to the withdrawal section, thereby adjusting the length of the lower looper thread pulled out by the pull-out section; a first input section that moves the needle thread adjusting section along the cross direction through a first operating wire; a second input section that moves the upper looper thread adjusting section and the lower looper thread adjusting section along the cross direction through a second operating wire; and an adjustment interlocking section that interlocks the upper looper thread adjusting section and the lower looper thread adjusting section when the needle thread adjusting section moves through the second operating wire.an adjustment input unit that reels in an intermediate portion of the first operating wire to move the needle thread adjustment unit along the intersecting direction, wherein when reeling in an intermediate portion of the first operating wire to move the needle thread adjustment unit, the adjustment input unit also reels in an intermediate portion of the second operating wire to suppress or reduce interlocking of the lower looper thread adjustment unit and the upper looper thread adjustment unit associated with movement of the needle thread adjustment unit by the adjustment interlocking unit. (2) The overedge sewing machine according to (1), wherein the first input unit includes a stitch pitch setting input unit. (3) The overedge sewing machine according to (1) or (2), wherein the second input unit includes an overedge width setting input unit. (4) The overedge sewing machine according to any one of (1) to (3), having a stitch type selection unit that, when a stitch type is selected, adjusts the respective thread let-off amounts of the needle thread, the upper looper thread, and the lower looper thread to the thread let-off amounts corresponding to the selected stitch type. (5) The overedge sewing machine according to any one of (1) to (4), which has a thickness detection unit that adjusts the respective thread payout amounts of the needle thread, the upper looper thread, and the lower looper thread according to the thickness of the sewn material. (6) The overedge sewing machine according to (1) to (5), which has a looper thread tension setting input unit that sets and inputs the thread tensions of the upper looper thread and the lower looper thread.

[0125] This application is based on Japanese Patent Application No. 2023-177148 filed on October 13, 2023, the contents of which are incorporated herein by reference.

Claims

1. An overedge sewing machine comprising: a needle up-down movement mechanism for moving a sewing needle having a needle thread passed therethrough up and down; a lower looper mechanism having a lower looper for passing a lower looper thread through a loop of the needle thread; an upper looper mechanism having an upper looper for passing an upper looper thread through a loop of the lower looper thread; a feed mechanism for feeding a workpiece; and a thread pay-out mechanism for paying out the needle thread, the lower looper thread and the upper looper thread from a thread supply source in synchronization with each needle drop, wherein the thread pay-out mechanism comprises: an upstream guide section having thread introduction sections for each of the needle thread, the upper looper thread and the lower looper thread, and a downstream guide section having thread outlet sections for each of the needle thread, the upper looper thread and the lower looper thread, a pull-out section that moves back and forth between the upstream guide section and the downstream guide section in a direction intersecting the needle thread, the upper looper thread, and the lower looper thread passing from each of the introduction sections to the outlet section, thereby pulling out the needle thread, the upper looper thread, and the lower looper thread from each of the supply sources; a needle thread adjustment section that moves along the intersecting direction between the upstream guide section and the downstream guide section, thereby varying the path of the needle thread passing from the introduction section to the outlet section, thereby adjusting the pull-out length of the needle thread by the pull-out section; an upper looper thread adjustment section that moves along the intersecting direction between the upstream guide section and the downstream guide section, thereby varying the path of the upper looper thread passing from the introduction section to the outlet section, thereby adjusting the pull-out length of the upper looper thread by the pull-out section; a lower looper thread adjustment section which moves along the intersecting direction between the upstream guide section and the downstream guide section to vary the path of the lower looper thread from the introduction section to the lead-out section, thereby adjusting the pull-out length of the lower looper thread by the pull-out section; a first input section which moves the needle thread adjustment section along the intersecting direction through a first operation wire; a second input section which moves the upper looper thread adjustment section and the lower looper thread adjustment section along the intersecting direction through a second operation wire; an adjustment interlocking section which interlocks the upper looper thread adjustment section and the lower looper thread adjustment section when the needle thread adjustment section moves through the second operation wire; and an adjustment input section which moves the needle thread adjustment section along the intersecting direction by pulling on a middle portion of the first operation wire,The adjustment input unit, when pulling on a middle portion of the first operating wire to move the needle thread adjustment unit, also pulls on a middle portion of the second operating wire to suppress or reduce the linkage of the lower looper thread adjustment unit and the upper looper thread adjustment unit that accompanies the movement of the needle thread adjustment unit by the adjustment linkage unit.

2. The overedge sewing machine according to claim 1, wherein the first input section includes a stitch pitch setting input section.

3. The overedge sewing machine according to claim 1, wherein the second input section includes an input section for setting an overedge width.

4. An overedge sewing machine as described in claim 1, further comprising a sewing type selection unit which, when a sewing type is selected, adjusts the respective thread payout amounts of the needle thread, the upper looper thread and the lower looper thread to the thread payout amounts corresponding to the selected sewing type.

5. An overedge sewing machine as claimed in claim 1, further comprising a thickness detection section which adjusts the amount of thread payout of each of the needle thread, the upper looper thread and the lower looper thread in accordance with the thickness of the material being sewn.

6. An overedge sewing machine according to claim 1, further comprising a looper thread tension setting input section for setting and inputting thread tensions of said upper looper thread and said lower looper thread.

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