Edge overlock sewing machine

Abstract

An edge overlock sewing machine (100) is provided with: a first input unit (32) that moves a needle thread adjustment unit (24) along an intersecting direction; a second input unit (33) that moves an upper looper thread adjustment unit (25) and a lower looper thread adjustment unit (26) in conjunction with each other along the intersecting direction; an adjustment interlocking unit (27) that interlocks the upper looper thread adjustment unit (25) and the lower looper thread adjustment unit (26) when the needle thread adjustment unit (24) moves; and a third input unit (37) that, while allowing the interlocking by the second input unit (33) and the adjustment interlocking unit (27), inputs adjustment of the relative positions of a thread locking unit (251) of the upper looper thread adjustment unit (25) and a thread locking unit (261) of the lower looper thread adjustment unit (26) along the intersecting direction.

Description

Overedge sewing machine

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

[0002] Conventional overedge sewing machines pay out a predetermined amount of needle thread and looper thread from a thread supply source for each stitch, thereby optimizing the thread tension of each thread while sewing. Furthermore, conventional overedge sewing machines automatically adjust the amount of thread payout for each thread depending on 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 machine described above has a structure in which the various thread payout mechanisms are interlocked, and when the thread payout amount of the needle thread is adjusted, the thread payout amount of the looper thread is also interlocked. In this case, it is possible to reduce the burden of adjustment work compared to adjusting each thread individually, and it is convenient for users. However, adjustment of the thread payout amount between the upper looper thread and the lower looper thread is only performed in two stages by changing the pattern based on the structure in which the various thread payout mechanisms are interlocked as described above, and it was not possible to meet requests such as changing the texture of the stitch by arbitrarily adjusting the thread payout amount between the upper looper thread and the lower looper thread.

[0005] An object of the present disclosure is to adjust the amount of yarn let-out between the upper looper thread and the lower looper thread.

[0006] The overedge sewing machine according to the present disclosure comprises: 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, the thread reeling mechanism comprising: 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 passing from each of the introduction sections to the outlet section to pull 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 has a thread locking section that restrains the needle thread in the intersecting direction, and moves between the upstream guide section and the downstream guide section along the intersecting direction to vary 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 has a thread locking section that restrains the upper looper thread in the intersecting direction, and moves between the upstream guide section and the downstream guide section along the intersecting direction to vary 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 adjusting unit that has a thread locking unit that restrains the lower looper thread in the crossing direction, and that moves along the crossing direction between the upstream guide unit and the downstream guide unit to vary the path of the lower looper thread from the introduction unit to the withdrawal unit, thereby adjusting the pull-out length of the lower looper thread by the pull-out unit; a first input unit that moves the needle thread adjusting unit along the crossing direction; a second input unit that moves the upper looper thread adjusting unit and the lower looper thread adjusting unit in conjunction with each other along the crossing direction; and an adjustment interlocking unit that interlocks the upper looper thread adjusting unit and the lower looper thread adjusting unit when the needle thread adjusting unit moves.The present invention is characterized in that it is provided with a third input section that inputs adjustment of the relative positions of the thread locking section of the upper looper thread adjustment section and the thread locking section of the lower looper thread adjustment section along the crossing direction while allowing linkage between the second input section and the adjustment linkage section.

[0007] The overedge sewing machine of the present disclosure, with the above-described configuration, is capable of adjusting the amount of thread let-out between the upper looper thread and the lower looper thread, and the thread tension of the upper looper thread and the lower looper thread can be adjusted individually without mutual restriction.

[0008] 1 is a perspective view of an overedge sewing machine according to an embodiment of the present disclosure; FIG. 1 is a perspective view of a thread reeling mechanism; FIG. 2 is an exploded perspective view of the thread reeling mechanism; FIG. 3 is a perspective view from a direction in which the front sides of two reeling plates are visible; FIG. 4 is a perspective view showing a state before needle threads are reeled out by the reeling plates; FIG. 5 is a perspective view showing a state during needle thread reeling out by the reeling plates; FIG. 6 is an explanatory view showing thread reeling out due to a change in thread path; FIG. 7 is a perspective view showing the front side of an upstream guide plate 21 provided with a reeling drive mechanism; FIG. 8 is a perspective view of upstream and downstream thread grippers; FIG. 9 is a perspective view of a grip drive mechanism; FIG. 10 is a perspective view of an end face cam; FIG. 11 is a rear view of a configuration supported on the rear surface 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 surface of the upstream guide plate when a single-needle thin overedge stitch is selected; FIG. 13 is a rear view of a configuration supported on the rear surface of the upstream guide plate when a single-needle wrap stitch is selected. 16 is a right side view of the adjustment input portion; FIG. 17 is a perspective view of a third input portion provided on a lower looper thread adjustment plate; FIG. 18 is a perspective view of the third input portion as seen from a direction different from that of FIG. 16; and FIG. 19 is an exploded perspective view of the third input portion.

[0009] [Overview of the Overlock Sewing Machine] An overlock sewing machine 100 according to an embodiment of the present disclosure will now be described in detail. FIG. 1 shows a perspective view of the overlock sewing machine 100. 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 will be referred to as the "left," the right-hand side as the "right," the vertically upward direction will be referred to as the "up," and the vertically downward direction will be referred to as the "down." The front-to-back direction, left-to-right direction, and up-to-down direction are mutually orthogonal. In the following description, it is assumed that the overlock sewing machine 100 is installed on a horizontal surface, and the front-to-back direction and left-to-right direction are horizontal.

[0010] A so-called overlock machine is shown as an example of the overedge sewing machine 100. The overedge sewing machine 100 includes a sewing machine frame 110, a needle up-and-down movement mechanism that moves the sewing needle up and down, a lower looper mechanism equipped with a lower looper that passes the lower looper thread through a loop of the needle thread, an upper looper mechanism equipped with an upper looper that passes the upper looper thread through a loop of the lower looper thread, a feed mechanism that feeds the sewn material, a knife mechanism that trims the side edge (e.g., the right edge) of the sewn material to trim the sewing edge, and a thread reeling mechanism 2 that reels 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, on which a sewing material is placed and sewing work is performed. A needle plate 114 is provided on the upper left surface of the bed portion 111, 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 performs sewing using a maximum of four threads: needle thread T1, needle thread T2, upper looper thread T3, and lower looper thread T4. The thread stand 120 has four support shafts 121 to 124 that 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. The support shafts 121 to 124 support, in order 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 and has notched guide portions through which the left needle thread T1, right needle thread T2, upper looper thread T3, and lower looper thread T4 are inserted. The left needle thread T1, right needle thread T2, upper looper thread T3, and 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 are the same as those well known in overedge sewing machines (lockstitch machines), and therefore detailed description will be omitted. The needle up / down movement mechanism has a needle bar that holds a sewing needle with a thread threaded therethrough at its lower end, and 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, and the overedge sewing machine 100 can 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 or 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 has been 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 forward from the right end of the needle plate to above the needle plate. This allows the descending sewing needle to be inserted into the loop of the upper looper thread formed when the upper looper is moved backward. 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 entwining 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 through a power transmission mechanism, thereby achieving synchronization between the mechanisms.

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

[0019] The knife mechanism has a moving knife that moves up and down at the right end of the needle plate 114. Working in conjunction with the fixed knife, it cuts off the right edge of the sewn material as it passes over the needle plate 114. The moving knife is positioned behind the sewing needle and cuts off the sewn 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 edge with the moving knife ensures that the distance from the needle point to the right edge of the sewn material is a constant width. Overedge stitching creates a seam in which the upper looper thread and lower looper thread cross from the right edge of the sewn material to the needle point, and the distance from the needle point to the right edge of the sewn material defines the overedge width (sewing width). The cutting position of the moving knife in the left-right direction can be adjusted by rotating the overedge width adjustment knob 132 in the overedge width setting input section. Adjusting the cutting position with the overedge width adjustment knob 132 is equivalent to setting the overedge width.

[0020] [Thread reeling mechanism: overview] Figure 2 is a perspective view of the thread reeling mechanism 2, and Figure 3 is an exploded perspective view of 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, a looper thread tension setting input portion 36, and a third input portion 37.

[0021] 3, the thread reeling mechanism 2 is arranged in the upper inside portion of the arm portion 113, from front to rear, in this order, on the upper side, 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 the flat surface of each is inclined so that it is perpendicular to the downward rearward diagonal 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 lower portion along the left-right direction, through which at least two of the four support posts 215 erected vertically on the rear surface of the upstream guide plate 21 pass. The upper and lower portions of each support post 215 are formed flat, and the flat surfaces on the upper and lower sides come into sliding contact with 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. 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. In addition, spacers (not shown) through which each support 215 passes are inserted between each of the upstream guide plate 21, the first pull-out plate 23, the upper looper thread adjustment plate 25, the needle thread adjustment plate 24, the lower looper thread adjustment plate 26, the second pull-out plate 23, and the downstream guide plate 22, and a predetermined gap is formed between adjacent plates in the front and rear.

[0023] The downstream guide plate 22, which has four insertion holes formed therein for inserting screws or other fastening members (not shown), is fastened and fixed to the tip ends of the four support posts 215. Therefore, between the upstream guide plate 21 and the downstream guide plate 22, 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 in the left-right direction.

[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 of the introduction sections 211-214 is formed as a vertically long notch that opens upward on the upper edge of the upstream guide plate 21. Furthermore, 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 of the outlet sections 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, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 are inserted into the four thread guide grooves 115-118, they enter the introduction sections 211-214 and the outlet sections 221-224 as they are. 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 left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 are restrained in the left-right direction by the introduction sections 211-214 and the outlet sections 221-224, respectively. Each of the threads T1 to T4 is supplied from the front side to the rear side of the upstream guide plate 21 and is consumed by sewing behind the downstream guide plate 22.

[0026] [Thread payout mechanism: pull-out plates] The two pull-out plates 23 move back and forth between the upstream guide plate 21 and the downstream guide plate 22 in a direction intersecting the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 that extend from their respective introduction sections 211 to 214 to their respective withdrawal sections 221 to 224 (for example, the left-right direction that is perpendicular to the direction) to pull out the needle threads T1, T2, upper looper thread T3, and lower looper thread T4 from their respective supply sources. The target value for the amount of each thread to be paid out is equal to the length consumed by sewing each stitch. Furthermore, since the needle threads T1, T2, upper looper thread T3 and lower looper thread T4 each have a different length consumed for each stitch, 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 can be individually changed using the needle thread adjustment plate 24, upper looper thread adjustment plate 25 and lower looper thread adjustment plate 26, thereby making it possible to adjust the amount of thread pulled out by the pull-out plate 23.

[0027] Figure 4 is a perspective view of the two drawer plates 23, viewed from the direction in which the front sides are visible. 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-hand portion 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 an overlapping state so that there is no misalignment when viewed perpendicular to the plate surfaces.

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

[0029] The pull-out plate 23 is formed with insertion sections 231 to 234 into which the yarns T1 to T4 individually enter as they 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. Each of the insertion sections 231 to 234 is formed as a triangular cutout that is open at the top. Each of the insertion sections 231 to 234 has a contact section 231 a to 234 a 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 23. Fig. 6 is an explanatory diagram showing thread payout due to a change in the thread path. The front and rear pull-out plates 23 are given a reciprocating motion by moving rightward and leftward relative to the upstream guide plate 21 and the downstream guide plate 22 by a pay-out drive mechanism 31, which will be described later. 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 paths that form a single mountain that gently convex to the right, as shown by the colored lines 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 paths that form a double mountain that significantly convex to the right, as shown by the white lines in Fig. 6. Then, when each pull-out plate 23 returns to the left, the increase in the path length during pulling 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] [Yarn reeling mechanism: reeling drive mechanism] The reeling 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 reeling drive mechanism 31 is provided. As shown in the figure, the reeling 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 fixedly mounted on the drive shaft 311.

[0033] The drive shaft 311 receives power from the sewing machine motor and rotates in 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 roller 236 of the front drawer plate 23 described above protrudes from the front side of the upstream guide plate 21 through a rectangular opening 216 that is elongated in the left-right direction and formed through 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 out the sewing needles when they are ascending, and to move each drawer plate 23 to the left when they are descending.

[0034] [Thread Payout Mechanism: Each Adjustment Plate] As shown in Figure 3, the needle thread adjustment plate 24 is disposed between the two draw-out plates 23 and has insertion sections 241, 242 through which the left needle thread T1 and the right needle thread T2, which pass from the inlet sections 211, 212 of the upstream guide plate 21 to the outlet sections 221, 222 of the downstream guide plate 22, enter individually. Each insertion section 241, 242 is a vertically long notch that opens upward at the upper edge of the needle thread adjustment plate 24. Each insertion section 241, 242 functions as a thread locking section that restrains the left needle thread T1 and the right needle thread T2 in the left-right direction. Therefore, by moving the needle thread adjustment plate 24 in the left-right direction, the left needle thread T1 and the right needle thread T2 can be moved closer to each other in the left-right direction.

[0035] The upper looper thread adjusting plate 25 is disposed between the two pull-out plates 23, and has an insertion portion 251 formed therein through which the upper looper thread T3 passes as it passes from the introduction portion 213 of the upstream guide plate 21 to the extraction portion 223 of the downstream guide plate 22. 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 insertion portion 251 functions as a thread locking portion that restrains the upper looper thread T3 in the left-right direction. Therefore, by moving the upper looper thread adjusting plate 25 in the left-right direction, the upper looper thread T3 can be shifted in the left-right direction.

[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 through which the lower looper thread T4 passes as it passes from the introduction portion 214 of the upstream guide plate 21 to the extraction portion 224 of the downstream guide plate 22. 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 insertion portion 261 functions as a thread locking portion that restrains the lower looper thread T4 in the left-right direction. Therefore, by moving the lower looper thread adjusting plate 26 in the left-right direction, the lower looper thread T4 can be shifted left and right.

[0037] 3, the lower looper thread adjusting plate 26 is integrally formed by stacking a substantially flat first member 263 and a substantially flat second member 264. Two screw holes 263c are provided in the first member 263, and two elongated holes 264c are provided in the second member 264 along the left-right direction, and the first member 263 and the second member 264 are connected by two shoulder screws 265. The shoulder screws 265 are passed through the two elongated holes 264c of the second member 264, and the first member 263 and the second member 264 are connected in a state where they can slide relative to each other in the left-right direction.

[0038] The first member 263 has the above-mentioned guide hole formed therein, and is supported by the support 215 so as to be movable in the left-right direction. The first member 263 also has a leg portion 262 (connecting portion) extending downward, and is similarly connected to a leg portion 252 (connecting portion) extending downward from the upper looper thread adjusting plate 25 by a spring 332 (described later) (see FIG. 11 ). In contrast, the second member 264 has an insertion portion 261 formed therein through which the lower looper thread T4 is inserted. Therefore, the lower looper thread adjusting plate 26 moves in conjunction with the upper looper thread adjusting plate 25 in the left-right direction by the spring 332, and the relative positions of the insertion portion 251 and the insertion portion 261 in the left-right direction can be adjusted by moving the second member 264 relative to the first member 263.

[0039] A third input section 37 is provided between the first member 263 and the second member 264, which inputs adjustment of the distance between the insertion section 251 of the upper looper thread adjusting plate 25 and the insertion section 261 of the lower looper thread adjusting plate 26 in the left-right direction, while allowing interlocking by the second input section 33 and the adjustment interlocking section 27. The third input section 37 has a function of adjusting and maintaining the relative positions of the first member 263 and the second member 264 in the left-right direction. Details of this third input section 37 will be described later.

[0040] The function of each adjustment plate 24-26 will be explained using the aforementioned FIG. 6 . Here, needle threads T1 and T2 will be described as an example. The needle thread adjustment plate 24 can lock intermediate portions of the needle threads T1 and T2 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 shown in FIG. 6 at point M 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 along each of the threads T1 to T4 can be moved left and right using the insertion portions 241, 242, 251, and 261, thereby adjusting the length of thread being fed out by the two pull-out plates 23.

[0041] [Yarn reeling mechanism: yarn gripping section] 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 on 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 on the yarn consumption side.

[0042] 8 is a perspective view of the upstream and downstream thread gripping portions 29. Since the upstream thread gripping portion 29 and the downstream thread gripping portion 29 have the same configuration, the downstream thread gripping portion 29 will be mainly described here.

[0043] The downstream thread gripping section 29 includes four fixed plates 291 individually and fixedly attached to one side (for example, the left side) of each of the lead-out sections 221 to 224 on the rear surface of the downstream guide plate 22, four gripping plates 292 arranged opposite each of the fixed plates 291 with each of the lead-out sections 221 to 224 sandwiched between them when viewed from the direction perpendicular to the plate surface of the downstream guide plate 22, a support rod 293 that simultaneously penetrates and supports the four gripping plates 292, four springs 294 that individually press each of the gripping plates 292 toward the opposing fixed plate 291, and a support plate 295 that supports the right end of the support rod 293 and serves as a spring support for the rightmost spring 294.

[0044] 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-in sections 211 to 214.

[0045] The upright plate surface of each fixed plate 291 is perpendicular to the downstream guide plate 22. A through-hole is provided in the center of the plate surface of each fixed plate 291, and a support rod 293 is simultaneously inserted through it. Each fixed plate 291 has the function of gripping each of the yarns T1 to T4 in cooperation with each gripping plate 292, and the function of supporting the support rod 293 so that it can move in the left-right direction. 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, so that each fixed plate 291 also functions as a spring support.

[0046] 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 therethrough. The right end of the rightmost spring 294 is pressed against the support plate 295, and the support plate 295 functions as a spring support. Since there is no opposing gripping plate 292, the support plate 295 does not have the function of gripping the thread. The support plate 295 does not have to be made of the same material as the fixed plate 291, as long as the right end of the support rod 293 is inserted therethrough and the right end of the rightmost spring 294 is pressed against the support plate 295.

[0047] Each gripping plate 292 is circular, and a support rod 293 passes through its center. 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, and the support rod 293 is inserted through it. The left end of each spring 294 is in pressure contact with the respective gripping plate 292, and the right end is in pressure contact with 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.

[0048] The support rod 293 has a structure that restricts each of the gripping plates 292 from moving leftward from a predetermined support position, but allows each of the gripping plates 292 to move rightward from the predetermined support position. This restricting structure is, for example, a structure that locks each of the gripping plates 292 from the left by an enlarged portion of the support rod 293 or a protrusion 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.

[0049] [Yarn reeling mechanism: gripping drive mechanism] Figure 9 is a perspective view of the gripping drive mechanism 30. The upstream thread gripping section 29 and the downstream thread 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 thread gripping section 29 is in a released state and the downstream thread gripping section 29 is in a gripping state, and when the pull-out plate 23 returns to its original position, the upstream thread gripping section 29 is in a gripping state and the downstream thread gripping section 29 is in a released state.

[0050] The grip drive mechanism 30 shares the drive shaft 311 of the aforementioned reel-out drive mechanism 31 as its drive shaft. The grip drive mechanism 30 has an end face cam 301 provided on the left end of the drive shaft 311, an upstream follower (not shown) made of a roller that comes into contact with the cam surface of the end face cam 301 in a rear area RA (see FIG. 10 ) of the cam surface, an upstream actuating arm 302 that holds the upstream follower and performs a swinging motion, a downstream follower (not shown) made of a roller that comes into contact with the cam surface of the end face cam 301 in a front area FA (see FIG. 10 ) of the cam surface, a downstream input arm 303 that holds the downstream follower and performs a swinging motion, and a downstream output arm 304 that swings in conjunction with the downstream input arm 303 and pushes the left end of the support rod 293 of the downstream yarn gripping portion 29 to the right.

[0051] FIG. 10 is a perspective view of 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 concavities and convexities formed at predetermined locations on its circumference. As shown in the figure, the roughly rear portion of the cam surface 301a is a rear area RA with which the upstream follower abuts, and the roughly front portion of the cam surface 301a is a front area FA with which the downstream follower abuts. In this way, by obtaining power at two locations 180° apart on the circumference of the single end cam 301, the upstream yarn gripping portion 29 and the downstream yarn gripping portion 29 can be alternately operated at timings that are shifted by half a rotational period of the drive shaft 311.

[0052] The upstream operating arm 302 is swingably supported at a position slightly below its upper end by the front end of a connecting cylinder 305. The connecting cylinder 305 penetrates and connects the upstream guide plate 21 and the downstream guide plate 22, and the connecting cylinder 305 is fixed facing in a direction perpendicular to the plate surface of the upstream guide plate 21. The upstream operating arm 302 slides along the outer circumferential surface of the front end of the connecting cylinder 305 to perform a swinging motion.

[0053] The upstream operating arm 302 has a portion below the connecting tubular portion 305 that holds the upstream follower, and receives a left-right swing motion from the end face cam 301. Furthermore, the upstream operating arm 302 has a portion above the connecting tubular portion 305 that swings, and can push the left end of the support rod 293 of the upstream thread gripping portion 29 to the right.

[0054] The downstream input arm 303 is fixedly connected to the front end of a connecting shaft 306 rotatably supported inside the connecting cylinder portion 305, 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, and its rear end is fixedly connected to the lower end of the downstream output arm 304 on the rear surface side of the downstream guide plate 22. The downstream input arm 303 receives swinging motion in the left and right directions 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 yarn gripping portion 29 to the right.

[0055] 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, and allowing the downstream thread gripping portion 29 to maintain the gripped state. Furthermore, the cam surface 301a of the end cam 301 is 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, and allowing the upstream thread gripping portion 29 to maintain the gripped state.

[0056] As a result, the gripping drive mechanism 30 can be operated in synchronization with the left and right movement of the two pull-out plates 23 so that when the pull-out plates 23 are pulled out, the upstream thread gripping portion 29 is in a released state and the downstream thread gripping portion 29 is in a gripping state, and when the pull-out plates 23 move back, the upstream thread gripping portion 29 is in a gripping state and the downstream thread gripping portion 29 is in a released state.

[0057] [Thread Payout Mechanism: First Input Unit] Figure 11 is a rear view of the configuration supported on the rear surface of the upstream guide plate 21. 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. That is, when the pitch adjustment knob 131 is operated in a direction that increases the stitch pitch, the first input unit 32 links the needle thread adjustment plate 24 in a direction that increases the payout amounts of the left and right needle threads T1, T2. As shown in Figures 1, 3, and 11, the first input unit 32 includes a first operation wire 321 having one end connected to the pitch adjustment knob 131, a guide pulley 322 provided on the lower rear surface of the upstream guide plate 21, a transmission lever 323 provided on the left end of the rear surface of the upstream guide plate 21, and a return spring 324 that biases the transmission lever 323 to rotate in a predetermined direction (clockwise in Figure 11). The first input unit 32 also includes guides or pulleys (not shown) that are arranged at various locations on the path of the first operating wire 321 from the pitch adjustment knob 131 to the guide pulley 322 .

[0058] 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, and the tension is increased or decreased 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 left, and is connected to the lower end of the guide pulley 322 from the right side.

[0059] The transmission lever 323 is long 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, and tension to the right is input from the first operating wire 321.

[0060] The transmission lever 323 has a branch 323a extending leftward at its vertical intermediate portion, and the branch 323a is connected to one end of the aforementioned return spring 324. The return spring 324 applies an 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.

[0061] The transmission lever 323 is connected by inserting a pin 323b provided at the upper end into a vertically long hole provided at the lower end of 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.

[0062] [Thread reeling mechanism: second input unit] The second input unit 33 is intended to interlock the overlock width adjustment knob 132, which is an input unit for setting the overlock width, with the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. In other words, when the overlock width adjustment knob 132 is operated in a direction that increases the overlock width, the second input unit 33 interlocks the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 in a direction that increases the amount of upper looper thread T3 and lower looper thread T4 that is reeled out. As shown in Figures 1, 3 and 11, the second input unit 33 has a second operating wire 331, one end of which is connected to the overlock width adjustment knob 132 and the other end of which is connected to the upper looper thread adjustment plate 25, a spring 332 that interlocks the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26, and a return spring 333 that urges the upper looper thread adjustment plate 25 to the right. The second input portion 33 also includes guides or pulleys (not shown) 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. In the following description, unless otherwise specified, it is assumed that the lower looper thread adjustment plate 26 is in a state in which the first member 263 and the second member 264 maintain their relative positions in the left-right direction.

[0063] 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, and 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 the tension to the upper looper thread adjustment plate 25. The other end of the second operating wire 331 extends from below, passes through a movable pulley 273 of the adjustment interlocking unit 27 (described later), turns rightward, and is connected to the upper looper thread adjustment plate 25 from the left side.

[0064] The spring 332 is a tension spring, and connects the leg 252 extending downward from the lower end of the upper looper thread adjusting plate 25 with 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, and while maintaining this arrangement, the spring 332 keeps the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 in close proximity to each other. Furthermore, since they are connected by the spring 332, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 can, in principle, be moved in the left-right direction while maintaining a constant interval between them.

[0065] The right end of the upper looper thread adjusting plate 25 has an arm 253 extending to the right, and 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, and applies tension to the upper looper thread adjusting plate 25 to the right through the arm 253, and applies tension in a direction that resists the tension to the left that the upper looper thread adjusting plate 25 receives from the second operating wire 331.

[0066] [Thread payout mechanism: adjustment interlocking unit] The adjustment interlocking unit 27 is intended to interlock the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 when the needle thread adjusting plate 24 moves through the second operating wire 331. In other words, when the needle thread adjusting plate 24 moves in a direction in which the payout amounts of the needle threads T1, T2 increase, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 also interlock in a direction in which the payout amounts of the upper looper thread T3 and the lower looper thread T4 increase. As shown in Figures 3 and 11 , the adjustment interlocking unit 27 has a interlocking plate 271 that moves left and right in conjunction with the rotation of the transmission lever 323 of the first input unit 32, a connecting link 272 that connects the transmission lever 323 and the interlocking plate 271, and a movable pulley 273 arranged in the cam hole 271a of the interlocking plate 271.

[0067] The interlocking plate 271 has two elongated holes at its upper end, through which the two leftmost posts of the four support posts 215 standing rearward from the upstream guide plate 21 are inserted. The interlocking plate 271 is disposed between the front drawer plate 23 and the needle thread adjustment plate 24 while being supported so as to be movable in the left-right direction. 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.

[0068] A cam hole 271a is formed through the downward extension of the interlocking plate 271. This cam hole 271a has a certain length in the up-down direction and a certain width in the left-right direction. The rotation shaft of a movable pulley 273 passes through the hole from front to rear, and 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.

[0069] 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 leftward in an interlocking manner 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 rightward in an interlocking manner due to the tension of the return spring 333.

[0070] [Thread reeling mechanism: stitch type selection unit] The thread reeling mechanism 2 has a stitch type selection unit 28 that, when a stitch type is selected, adjusts the amount of thread reeling out of each of the threads T1 to T4 individually so that it is appropriate for 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).

[0071] As shown in Figure 11, the stitch type selection unit 28 has a cam plate 281, a stitch type switching knob 282 that moves the cam plate 281 in the left-right direction, a base end link 283 and a tip end link 284 that support the movable pulley 273 mentioned above, a spacing member 285 that moves the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 apart, a base end link 286 and a tip end link 287 that support the spacing member 285, and a lock spring 288 that holds the cam plate 281 in four positions in the left-right direction.

[0072] The cam plate 281 is a long, flat plate that is long in the left-right direction and has four openings that are aligned in the left-right direction. Of these, the first and third openings from the left are linear in the left-right direction and are support holes into which support posts erected on the rear surface of the upstream guide plate 21 are inserted to support 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.

[0073] The second and fourth openings from the left of the cam plate 281 are cam holes 281a and 281b which 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.

[0074] The stitch type switching knob 282 is cylindrical and is 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 is formed on the outer peripheral surface of the stitch type switching knob 282 (see FIG. 12 ), and a pin 281c that fits into the spiral cam groove 282a is provided on the front surface of the right end of the opposing cam plate 281. 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 left and right.

[0075] Furthermore, four wedge-shaped notches 281d are formed in a row at the lower end of the cam plate 281. The tip of a lock spring 288, which is a leaf spring with a wedge-shaped protrusion at the tip and is supported on the lower rear surface of the upstream guide plate 21, is adapted to fit into one of the 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 according to each of the four stitch types selected along the stitch type selection section 28, and can be held in each position by the lock spring 288.

[0076] The base end link 283 and the tip link 284 that support the movable pulley 273 are rotatably connected to each other, and the base end of the base end link 283 is rotatably supported by the left support pillar that supports the cam plate 281. Also, 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, the connecting portion between the base end link 283 and the tip link 284 is provided with a pin 283a that protrudes rearward and fits 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, and the movable pulley 273 can also move up and down via the tip link 284.

[0077] The separating member 285 is supported at the tip of the base end link 286 and the tip end link 287 in a state where it is interposed between the leg 252 of the upper looper thread adjusting plate 25 and the leg 262 of the first member 263 of the lower looper thread adjusting plate 26, which are adjacent to each other. The separating member 285 is cylindrical, and can separate the leg 252 and the leg 262 to the left and right by moving upward.

[0078] 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, and 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, and via the tip link 287, the separation member 285 can also move up and down.

[0079] The following describes how the amount of feed of each of the threads T1 to T4 changes 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 the twin-needle overedge stitch (twin-needle lock stitch) of (1) above is selected, Figure 12 shows the operating state of the stitch type selection unit 28 when the single-needle overedge stitch (single-needle lock stitch) of (2) above is selected, Figure 13 shows the operating state of the stitch type selection unit 28 when the single-needle fine overedge stitch (single-needle fine lock stitch) of (3) above is selected, and Figure 14 shows the operating state of the stitch type selection unit 28 when the single-needle wrap stitch (single-needle wrap lock stitch) of (4) above is selected. The following description will be made assuming that the operating state of the stitch type selection unit 28 when the twin-needle overedge stitch (twin-needle lock stitch) of (1) above is selected as shown in Figure 11 is a state in which each of the threads T1 to T4 is fed out at a reference value.

[0080] In the case of twin-needle overedge stitching (1) shown in Figure 11, the cam plate 281 is set to the leftmost position by operating the stitch type changeover knob 282. In this case, the pin 283a is set to 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 same applies to the movable pulley 273). In Figure 11, the pin 283a and movable pulley 273 are set to the "upper" position.

[0081] 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 (similarly to the separator 285). In Figure 11, the pin 286a and separator 285 are in the "down" position.

[0082] In the case of the single-needle overedge stitch (2) shown in Figure 12, the left sewing 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 in the "middle" position. 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. Because the needle thread adjusting plate 24 does not move, 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.

[0083] On the other hand, in the right cam hole 281b, the pin 286a and the separating member 285 maintain the "down" position because in the case of single-needle overedge stitching, the relative ratio of the consumption amounts of the upper looper thread T3 and the lower looper thread T4 does not change.

[0084] In the case of the single-needle fine overlock stitch (single-needle fine lock stitch) shown in Figure 13 (3), 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 "down." 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.

[0085] On the other hand, in the right cam hole 281b, the pin 286a and the separating member 285 maintain the "down" 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.

[0086] In the case of the single-needle overlock stitch (single-needle overlock stitch) shown in Figure 14 (4), the left sewing needle is removed and the left needle thread T1 is not used. The overlock stitch is performed by folding the right edge of the workpiece to the left at a specified width and overlapping it (in a rolled state). As shown in Figure 14, the cam plate 281 moves to the rightmost position by operating the stitch type selector knob 282. In this case, the pin 283a rises within the left cam hole 281a, and the pin 283a and the movable pulley 273 are positioned "center." The rise of the movable pulley 273 generates tension in the second operating wire 331, and the upper looper thread adjustment plate 25 moves further to the left than in the case of the single-needle fine-edge overlock stitch (3) above.

[0087] Meanwhile, in the right cam hole 281b, the pin 286a and the separating member 285 rise to the "up" position. As a result, 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. Also, the lower looper thread adjusting plate 26 moves to the right, reducing the amount of lower looper thread T4 that is paid out. 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 quantity than the lower looper thread T4.

[0088] Furthermore, even if the position of the cam plate 281 is switched by operating the stitch type switching knob 282 according to the stitch type (1) to (4) above, the needle thread adjustment plate 24 does not move, and the amount of needle threads T1 and T2 that are fed out does not fluctuate.

[0089] [Thickness Detecting Unit] The purpose of the thickness detecting unit 35 is to adjust the amount of each of the threads T1 to T4 that is fed in accordance with the thickness of the sewn material on the needle plate 114. As shown in Fig. 2, the thickness detecting unit 35 includes a thickness detecting lever 351 as a thickness detecting member that rotates in conjunction with the up and down movement of a presser foot (not shown) that presses down on the sewn material from above on the needle plate 114, a support link 352 that rotates together with the thickness detecting lever 351, and a pulley 353 that is rotatably supported on the rotating end of the support link 352.

[0090] The thickness detection lever 351 is installed so that its left end can rotate left and right by a link (not shown) that is linked to the presser bar. It is urged leftward by the tension of the first operation wire 321, and as the thickness of the material to be sewn on the needle plate increases, its left end moves leftward. The support link 352 supports the pulley 353 at its lower end and rotates in the same direction as the rotation of the thickness detection lever 351. In other words, when the left end of the thickness detection lever 351 moves leftward, the lower end of the support link 352 rotates leftward. The pulley 353 is arranged to abut from the right side against the midpoint of the first operation wire 321 that extends from the bottom (pitch adjustment knob 131) to the guide pulley 322 of the first input portion 32.

[0091] With the above configuration, as the material to be sewn becomes thicker, the pulley 353 moves to the left, and therefore the middle portion of the first operation wire 321 leading from below to the guide pulley 322 of the first input portion 32 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 also moves the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 to the left. Therefore, it is possible to make adjustments such that the payout amount of each of the threads T1 to T4 increases as the material to be sewn becomes thicker, and decreases as the material to be sewn becomes thinner.

[0092] [Looper thread tension setting input section] The looper thread tension setting input section 36 is a means for arbitrarily increasing or decreasing the thread tension of the upper looper thread T3 and the lower looper thread T4 by adjusting the thread let-off amount by the thread let-off mechanism 2. It has a looper thread tension adjustment knob 361 which is the setting input section for the thread tension of the upper looper thread T3 and the lower looper thread T4, a support link 362 which rotates in conjunction with the rotation adjustment operation of the looper thread tension adjustment knob 361, and two pulleys 363, 364 provided at the base end and the rotating end of the support link 362.

[0093] 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 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 performs a rotational movement. The upper end of the support link 362 is connected to the looper thread tension adjustment knob 361 or a member that rotates integrally with the looper thread tension adjustment knob 361, and rotates in conjunction with the direction of rotation of the looper thread tension adjustment knob 361.

[0094] The pulley 363 provided at the lower end of the support link 362 is disposed so as to abut, for example, from the left side, against the intermediate 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 provided at the upper end of the support link 362 is disposed immediately above the pulley 363, so as to abut, for example, from the right side, against the intermediate portion of the second operation wire 331.

[0095] 2, the upper pulley 364 comes into contact with the lower pulley 363 from the right side, 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, moving 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.

[0096] 2, the upper pulley 364 moves to the right relative to the lower pulley 363, reducing the amount of pulling in. 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 letting out 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.

[0097] In this way, the looper thread tension setting input unit 36 ​​can arbitrarily increase or decrease the thread tension of the upper looper thread T3 and the lower looper thread T4 without moving the needle thread adjusting plate 24.

[0098] [Adjustment input unit] The adjustment input unit 34 aims to suppress or reduce 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, by also pulling on the middle part of the second operation wire 331 when moving the needle thread adjustment plate 24 by pulling on the middle part of the first operation wire 321 in order to adjust the thread tension of the needle threads T1 and T2.

[0099] 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, and adjusts the thread tension of the needle threads T1 and T2 by manually pulling on a middle portion 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 middle portion 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.

[0100] The adjustment input unit 34 includes a pair of first abutment pulleys 341 that abut against a midpoint of the first operation wire 321 from one side (for example, the rear side), a pair of second abutment pulleys 342 that abut against a midpoint of the second operation wire 331 from one side (for example, the rear side), a first pull-out pulley 343 that half-winds the loop of the first operation wire 321 that has been pulled out from between the pair of first abutment pulleys 341, a second pull-out pulley 344 that half-winds the loop of the second operation wire 331 that has been pulled out from between the pair of second abutment pulleys 342, a support link 345 that supports the first pull-out pulley 343 and the second pull-out pulley 344, a support bracket 346 that rotatably supports the support link 345 by a support shaft 346a, a lever member 347 that inputs a rotational movement to the support link 345, and a needle thread tension adjustment knob 348 that is movable up and down on the rear cover of the overedge sewing machine 100.

[0101] The pair of first abutment pulleys 341 are arranged vertically at a fixed interval, and the first operation wire 321 is pulled out in a loop so as to detour rearward from between the two first abutment pulleys 341. This looped first operation wire 321 is wound halfway around a range that is approximately halfway around the rear side of a first pull-out pulley 343 that is arranged rearward of the pair of first abutment pulleys 341. If the first pull-out pulley 343 moves rearward in this state, the first operation wire 321 is pulled out excessively, and therefore tension increases on the downstream side of the first operation wire 321, and if the first pull-out pulley 343 moves forward, the amount of pull-out of the first operation wire 321 decreases, and therefore tension also decreases on the downstream side of the first operation wire 321.

[0102] The pair of second abutment pulleys 342 are arranged vertically at a fixed interval, and the second operation wire 331 is pulled out in a loop so as to detour rearward from between the two second abutment pulleys 342. The looped 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, which is arranged rearward of the pair of second abutment pulleys 342. If the second pull-out pulley 344 moves rearward in this state, the second operation wire 331 is pulled out excessively, and therefore the tension on the downstream side of the second operation wire 331 increases, whereas if the second pull-out pulley 344 moves forward, the amount of pull-out of the second operation wire 331 decreases, and the tension on the downstream side of the second operation wire 331 also decreases.

[0103] 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 via a shaft extending in the left-right direction. The support link 345 is elongated generally in the vertical direction, and 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.

[0104] 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 white 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.

[0105] In other words, when the support link 345 is rotated clockwise, the first pullout pulley 343 moves away from the first operation wire 321, increasing the tension, and the needle thread adjusting plate 24 moves 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 pullout 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.

[0106] 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.

[0107] The support link 345 is rotated from the needle thread tension adjustment knob 348 through the lever member 347. The lever member 347 is rotatable by a shaft 347a that extends in the left-right direction, and a rotating end portion 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, and is loosely inserted into an engagement hole 345a provided in the lower end portion of the support link 345. The rotating end portion of the lever member 347 has a spherically expanded tip, and is inserted into the needle thread tension adjustment knob 348. The inner bottom portion of the needle thread tension adjustment knob 348 is a spherical concave surface that can slide on the spherical rotating end portion 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.

[0108] When the lever member 347 rotates, the engaging protrusion 347b moves around the shaft 347a, and can rotate the support link 345 via the engaging hole 345a. Although the lever member 347 and the support link 345 have significantly different rotation radii, the engaging hole 345a is an elongated hole that extends along the radial direction of the support link 345, and therefore can transmit the rotational movement from the lever member 347 to the support link 345, allowing for the difference in rotation radii.

[0109] [Thread reeling mechanism: third input unit] The thread tensions of the upper looper thread T3 and the lower looper thread T4 can be adjusted by the looper thread tension setting input unit 36 ​​without affecting the thread tensions of the needle threads T1, T2. However, in the case of the looper thread tension setting input unit 36, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are moved together in an interlocking manner, so it was not possible to adjust the thread tensions of the upper looper thread T3 and the lower looper thread T4 individually. Furthermore, although the stitch type selecting unit 28 can change the mutual distance between the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 by the spacing member 285, it is only possible to switch between two mutual distances using the upper and lower positions of the spacing member 285. Therefore, the third input section 37 is intended to enable input of adjustment of the mutual distance in the left-right direction between the insertion section 251 of the upper looper thread adjustment plate 25 and the insertion section 261 of the lower looper thread adjustment plate 26, while allowing without interfering with the linkage between the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 by the second input section 33 or the linkage between the needle thread adjustment plate 24 and the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 by the adjustment linkage section 27.

[0110] Fig. 16 is a perspective view of the third input portion 37 provided on the lower looper thread adjusting plate 26, Fig. 17 is a perspective view seen from another direction, and Fig. 18 is an exploded perspective view. As shown in Fig. 3 and Figs. 16 to 18, the third input portion 37 has a screw shaft 371 along the left-right direction that connects the first member 263 and the second member 264 that constitute the lower looper thread adjusting plate 26, an input knob 372 as an operation input portion that rotates the screw shaft 371, a movable nut 373 that screws onto the screw shaft 371, and a support bracket 374 that supports the input knob 372.

[0111] The downstream guide plate 22 has a right end bent forward and a side surface 225 that is perpendicular to the left-right direction. The support bracket 374 is attached and supported by screws to the front surface of the downstream guide plate 22 near the right end. The support bracket 374 has an attachment surface parallel to the front surface of the downstream guide plate 22 and a support surface bent forward from the right end of the attachment surface. The support surface of the support bracket 374 faces closely to the left side of the side surface 225 of the downstream guide plate 22. Support holes 225a and 374a that support the input knob 372 are formed concentrically in the side surface 225 of the downstream guide plate 22 and the support surface of the support bracket 374.

[0112] The input knob 372 is a generally cylindrical shape with a central axis aligned in the left-right direction, and the right portion serves as an input section that is gripped by hand to rotate the knob. As shown in Figure 1, the input section of the input knob 372 is provided so as to be operable from outside the overedge sewing machine 100. The left end of the input knob 372 is inserted into the support hole 225a of the downstream guide plate 22 and the support hole 374a of the support bracket 374, and is rotatably supported therein.

[0113] A gear 372a of the ratchet mechanism is formed on the outer peripheral surface of the left end of the input knob 372, between the side surface 225 of the downstream guide plate 22 and the support surface of the support bracket 374. The base end of a leaf spring 375 extending forward is fixedly supported by screws on the mounting surface of the support bracket 374. A wedge-shaped protrusion that meshes with the gear 372a of the input knob 372 is formed on the front end of this leaf spring 375. In other words, the gear 372a and the leaf spring 375 form a ratchet mechanism. Therefore, the input knob 372 can be rotated in increments of the pitch of the gear 372a, and the leaf spring 375 maintains the position (rotation angle) after operation.

[0114] The input knob 372 is penetrated throughout its entire length in the left-right direction, and the inner diameter of its inner circumferential surface is uniform throughout its entire length. Furthermore, a key groove 372b is formed on the inner circumferential surface of the input knob 372, extending from the left end to near the right end of the input knob 372. The left end of the key groove 372b opens to the left at the left end of the input knob 372.

[0115] The screw shaft 371 is a shaft body whose central axis runs in the left-right direction, and has a round rod-shaped insertion portion 371a at its right end that is inserted into the input knob 372, and a threaded portion 371b with a male thread at its left end. A flange portion 371c is provided between the insertion portion 371a and the threaded portion 371b, and the insertion portion 371a, the threaded portion 371b, and the flange portion 371c are all concentric.

[0116] A boss-like projection 371d that projects radially outward from the insertion portion 371a is provided on the outer peripheral surface at a longitudinally intermediate portion of the insertion portion 371a, and is inserted into the key groove 372b on the inside of the input knob 372 described above, rotating the input knob 372 and the screw shaft 371 together. The projection 371d is also movable in the axial direction inside the key groove 372b, allowing relative movement along the axial direction (left and right direction) between the input knob 372 and the screw shaft 371. Due to this structure that allows relative movement along the axial direction between the input knob 372 and the screw shaft 371, the third input portion 37 can allow the second input portion 33 to interlock the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26, and the adjustment interlock portion 27 to interlock the needle thread adjustment plate 24 with the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26.

[0117] The second member 264 is located in front of the first member 263 of the lower looper thread adjusting plate 26, and is connected to each other by two shoulder screws 265 with their plate surfaces overlapping. The right ends of both the first member 263 and the second member 264 are bent forward and have side surfaces 263a, 264a that are perpendicular to the left-right direction. The side surface 264a of the second member 264 is located on the left side of the side surface 263a of the first member 263, and they are closely opposed to each other. A through hole 263b is formed in the side surface 263a of the first member 263, through which the threaded portion 371b of the screw shaft 371 is inserted and held. A through hole 264b is formed in the side surface 264a of the second member 264, approximately concentric with the through hole 263b, through which the movable nut 373 is inserted and held.

[0118] The screw shaft 371 has a threaded portion 371b inserted into the through-hole 263b from the right side of the side surface 263a of the first member 263, and is held in place by an E-ring 377 to prevent it from slipping out to the right, with a spring washer 376 interposed between the right surface of the side surface 263a and the flange portion 371c. The E-ring 377 is fitted into a circumferential groove formed between the threaded portion 371b and the flange portion 371c of the screw shaft 371, and axially couples the first member 263 and the screw shaft 371 together while rotatably supporting the screw shaft 371 relative to the first member 263.

[0119] The movable nut 373 is cylindrical with a threaded hole formed therethrough in the left-right direction, and a portion of the outer circumferential surface is flattened in the left-right direction to form a generally D-shaped cross section. A flange portion 373a is formed at the left end of the movable nut 373. Meanwhile, the through-hole 264b in the side surface portion 264a of the second member 264 is formed in a generally D-shape corresponding to the cross-sectional shape of the movable nut 373, and the movable nut 373 is inserted from the left side of the side surface portion 264a. Furthermore, the movable nut 373 is held in place by an E-ring 378 on the right side of the side surface portion 264a with the flange portion 373a abutting against the left surface of the side surface portion 264a to prevent it from slipping out to the left. The E-ring 378 is fitted into a circumferential groove formed on the outer circumferential surface of the movable nut 373 and restricts left-right movement of the movable nut 373 relative to the side surface portion 264a. Note that the hole shape of through hole 264b in side surface portion 264a and the cross-sectional shape of movable nut 373 are both approximately D-shaped, and therefore, movable nut 373 is held in a state in which its rotation is restricted on side surface portion 264a of second member 264. Note that the hole shape of through hole 264b in side surface portion 264a and the cross-sectional shape of movable nut 373 are not limited to being approximately D-shaped, and may be any other shape as long as it is possible to restrict rotation.

[0120] The screw portion 371b of the screw shaft 371 rotatably supported on the side surface portion 263a of the first member 263 is threaded into a screw hole of a movable nut 373 held on the side surface portion 264a of the second member 264. Therefore, when the input knob 372 is rotated, the screw shaft 371 rotates integrally, and the movable nut 373 moves along the screw shaft 371. This makes it possible to adjust the position of the second member 264 in the left-right direction relative to the first member 263. The leg portion 262 of the first member 263 of the lower looper thread adjusting plate 26 is connected to the leg portion 252 of the upper looper thread adjusting plate 25 by the spring 332, so that the relative position of the insertion portion 261 of the lower looper thread adjusting plate 26 in the left-right direction relative to the insertion portion 251 of the upper looper thread adjusting plate 25 can be adjusted by rotating the input knob 372.

[0121] [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.

[0122] In the overedge sewing machine 100, when the pitch adjustment knob 131 is rotated in the direction that increases the stitch pitch, 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 stitch pitch.

[0123] Furthermore, when the pitch adjustment knob 131 is rotated in a direction that decreases the stitch pitch, the tension of the first operating wire 321 decreases, causing the needle thread adjustment plate 24 to move to the right. Furthermore, 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 reduces the amount of needle threads T1, T2, upper looper thread T3, and lower looper thread T4 that are fed out, thereby responding to the decrease in stitch pitch.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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 payout of the upper looper thread T3 and the lower looper thread T4 increases, and the thread tension of the upper looper thread T3 and the lower looper thread T4 can be reduced.

[0129] 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 payout of the upper looper thread T3 and the lower looper thread T4 decreases, and the thread tension of the upper looper thread T3 and the lower looper thread T4 can be increased.

[0130] Furthermore, when it is desired to reduce the thread tension of the needle threads T1, T2 without changing the thread tension of the looper threads T3, 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 that has been pulled in, and reduces the tension of the second operation wire 331. Therefore, the needle thread adjustment plate 24 moves to the left, and the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move left in conjunction with each other, but this is offset by the reduction in the tension of the second operation wire 331, suppressing fluctuations in the payout amounts of the upper looper thread T3 and the lower looper thread T4, increasing the payout amount of the needle threads T1, T2, and making it possible to reduce the thread tension of the needle threads T1, T2 alone.

[0131] Furthermore, when it is desired to increase the thread tension of the needle threads T1, T2 without changing the thread tension of the looper threads T3, 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 that has been pulled in, and increases the tension of the second operation wire 331. Therefore, the needle thread adjustment plate 24 moves to the right, and the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the right in conjunction with each other, but this is offset by the increase in the tension of the second operation wire 331, suppressing fluctuations in the payout amounts of the upper looper thread T3 and the lower looper thread T4, reducing the payout amount of the needle threads T1, T2, and making it possible to increase the thread tension of the needle threads T1, T2 alone.

[0132] Furthermore, when it is desired to increase the thread tension of the lower looper thread T4 relative to the upper looper thread T3, the input knob 372 of the third input portion 37 is rotated to move the second member 264 to the right relative to the first member 263 of the lower looper thread adjusting plate 26. As a result, only the second member 264 having the insertion portion 261 of the lower looper thread adjusting plate 26 moves to the right without moving the upper looper thread adjusting plate 25, thereby reducing the amount of payout of the lower looper thread T4 and increasing the thread tension.

[0133] Furthermore, when it is desired to reduce the thread tension of the lower looper thread T4 relative to the upper looper thread T3, the input knob 372 of the third input portion 37 is rotated to move the second member 264 to the left relative to the first member 263 of the lower looper thread adjusting plate 26. As a result, only the second member 264 having the insertion portion 261 of the lower looper thread adjusting plate 26 moves to the left without moving the upper looper thread adjusting plate 25, thereby increasing the amount of payout of the lower looper thread T4 and reducing the thread tension.

[0134] Furthermore, if you want to adjust the thread tension of the upper looper thread T3 and the thread tension of the lower looper thread T4 to any desired strength, you can adjust the thread tension of the upper looper thread T3 to the target strength using the looper thread tension setting input unit 36, and then adjust the thread tension of the lower looper thread T4 to the target strength using the third input unit 37.

[0135] [Technical Effects of the Overlock Sewing Machine] By providing the third input section 37, the overlock sewing machine 100 can adjust the left-right position of the insertion section 261 of the lower looper thread adjustment plate 26 relative to the insertion section 251 of the upper looper thread adjustment plate 25 without impairing the function of interlocking the lower looper thread adjustment plate 26 via the adjustment interlock section 27 in conjunction with adjustment of the position of the needle thread adjustment plate 24 by the first input section 32 or the function of adjusting the position of the lower looper thread adjustment plate 26 by the second input section 33. Therefore, it is possible to adjust the thread tension of the upper looper thread and the lower looper thread individually without them affecting each other.

[0136] In addition, the lower looper thread adjustment plate 26 has a first member 263 having a leg portion 262 as a connecting portion of the spring 332 and a second member 264 having an insertion portion 261 as a thread locking portion, and the third input portion 37 is configured to adjust the relative distance in the left-right direction between the first member 263 and the second member 264.Therefore, the position of the insertion portion 261 of the lower looper thread adjustment plate 26 can be adjusted without affecting the left-right position of the upper looper thread adjustment plate 25 connected by the spring 332, and the thread tension of the upper looper thread and the lower looper thread can be adjusted individually without further interaction between them.

[0137] Furthermore, the third input portion 37 connects the first member 263 and the second member 264 with a screw shaft 371 that extends in the left-right direction, and an input knob 372 that rotates the screw shaft 371 supports the screw shaft 371 so that it can move in the left-right direction. Therefore, when the lower looper thread adjusting plate 26 is interlocked with the upper looper thread adjusting plate 25 by the adjustment interlocking portion 27 or the second input portion 33, the input knob 372 does not restrict the movement of the lower looper thread adjusting plate 26 through the screw shaft 371, and it is possible to smoothly interlock the lower looper thread adjusting plate 26 with the upper looper thread adjusting plate 25.

[0138] The overedge sewing machine 100 also includes an adjustment input unit 34 that, when the needle thread adjustment plate 24 is moved by pulling on a midpoint of the first operation wire 321, also pulls on a midpoint of the second operation wire 331 to inhibit or reduce 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.

[0139] In addition, the overedge sewing machine 100 is configured so that the first input section 32 includes a pitch adjustment knob 131, so that it is possible to optimize the amount of payout and thread tension of each thread T1 to T4 in accordance with an increase or decrease in the stitching pitch through the first operating wire 321.

[0140] In addition, the overedge sewing machine 100 is configured so that the second input section 33 includes an overedge width adjustment knob 132, so that it is possible to optimize the amount of payout and thread tension of each looper thread T3, T4 in accordance with the increase or decrease in the overedge width through the second operating wire 331.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] [Others] The embodiments according to the present disclosure have been described above. However, the present disclosure is not limited to the above-described embodiments. For example, in the embodiments, a component integrally formed from a single member may be replaced with a component divided into multiple members 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 present invention.

[0145] For example, the input knob 372 of the third input portion 37 is supported by, but not limited to, the downstream guide plate 22. The input knob 372 may be configured to be supported by any member that does not move in the left-right direction.

[0146] Furthermore, the input knob 372 of the third input section 37 may be attached in a structure that moves left and right together with the first member 263 of the lower looper thread adjustment plate 26, provided that it does not become inoperable (for example, by being hidden inside the cover of the overedge sewing machine 100).

[0147] In addition, in the above embodiment, the lower looper thread adjustment plate 26 is configured as two members, a first member 263 and a second member 264, but the upper looper thread adjustment plate 25 may also be configured as two members, a first member having a leg portion 252 and a second member having an insertion portion 251, and the third input portion may be configured to adjust the relative positions of the first member and second member of the upper looper thread adjustment plate 25 in the left-right direction.

[0148] Furthermore, the arrangement of the pulleys 341 to 344 of the adjustment input unit 34 is not limited to the above example and can be arbitrarily changed as long as the same effect can be obtained. For example, while the example has been given in which 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 abutment pulley 344 relative to the second abutment pulley 342 are substantially the same, if these directions are reversed, 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, instead of making the support link 345 pivotable, the first pull-out pulley 343 and the second pull-out pulley 344 may move toward and away from the first abutment pulley 341 and the second abutment pulley 342 in a linear manner.

[0149] 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 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-out 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-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 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 passing from each of the introduction sections to the outlet section to pull 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 has a thread locking section that restrains the needle thread in the intersecting direction, and moves between the upstream guide section and the downstream guide section along the intersecting direction to vary 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 has a thread locking section that restrains the upper looper thread in the intersecting direction, and moves between the upstream guide section and the downstream guide section along the intersecting direction to vary 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 adjusting unit having a thread locking unit that restrains the lower looper thread in the crossing direction, and that moves along the crossing direction between the upstream guide unit and the downstream guide unit to vary the path of the lower looper thread from the introduction unit to the withdrawal unit, thereby adjusting the pull-out length of the lower looper thread by the pull-out unit; a first input unit that moves the needle thread adjusting unit along the crossing direction; and a second input unit that moves the upper looper thread adjusting unit and the lower looper thread adjusting unit in conjunction with each other along the crossing direction.an adjustment interlocking unit that interlocks the upper looper thread adjustment unit and the lower looper thread adjustment unit when the needle thread adjustment unit moves, and a third input unit that inputs an adjustment of the relative positions of the thread locking unit of the upper looper thread adjustment unit and the thread locking unit of the lower looper thread adjustment unit along the cross direction while allowing the interlocking by the second input unit and the adjustment interlocking unit. [2] The overedge sewing machine according to [1], characterized in that the second input unit has a spring that connects the upper looper thread adjustment unit and the lower looper thread adjustment unit, one of the upper looper thread adjustment unit and the lower looper thread adjustment unit has a first member that has a connecting portion of the spring and a second member that has the thread locking unit, and the third input unit adjusts the relative distance between the first member and the second member along the cross direction. [3] The overedge sewing machine according to [2], characterized in that the third input unit has a screw shaft extending along the transverse direction that connects the first member and the second member, and an operation input unit that rotates the screw shaft, the operation input unit supporting the screw shaft so that it can move along the transverse direction. [4] The overedge sewing machine according to [1], characterized in that the first input unit includes an input unit for setting a stitch pitch. [5] The overedge sewing machine according to [1], characterized in that the second input unit includes an input unit for setting an overedge width. [6] The overedge sewing machine according to [1], characterized in that it has a stitch type selection unit that, when a stitch type is selected, adjusts the respective thread let-out amounts of the needle thread, the upper looper thread, and the lower looper thread to the thread let-out amounts corresponding to the selected stitch type. [7] The overedge sewing machine according to [1], characterized in that it has a thickness detection unit that adjusts the respective thread let-out amounts of the needle thread, the upper looper thread, and the lower looper thread according to the thickness of the sewn material. [8] The overedge sewing machine according to [1], further comprising a looper thread tension setting input unit for inputting and setting thread tensions of the upper looper thread and the lower looper thread.

[0150] This application is based on Japanese Patent Application No. 2023-205062, filed on December 5, 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 along 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 to pull 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 has a thread locking section that restrains the needle thread in the intersecting direction, and moves along the intersecting direction between the upstream guide section and the downstream guide section to vary the path of the needle thread passing from the introduction section to the outlet section to adjust the pull-out length of the needle thread by the pull-out section; an upper looper thread adjustment section that has a thread locking section that restrains the upper looper thread in the intersecting direction, and moves along the intersecting direction between the upstream guide section and the downstream guide section to vary the path of the upper looper thread passing from the introduction section to the outlet section to adjust the pull-out length of the upper looper thread by the pull-out section; a lower looper thread adjustment section which has a thread locking section which restrains the lower looper thread in the cross direction, and which 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 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 cross direction; a second input section which moves the upper looper thread adjustment section and the lower looper thread adjustment section in conjunction with each other along the cross direction; and 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.a third input unit that inputs adjustment of the relative positions of the thread locking portion of the upper looper thread adjustment unit and the thread locking portion of the lower looper thread adjustment unit along the crossing direction while allowing linkage between the second input unit and the adjustment linkage unit.

2. The overedge stitch machine as described in claim 1, characterized in that the second input portion has a spring connecting the upper looper thread adjustment portion and the lower looper thread adjustment portion, either the upper looper thread adjustment portion or the lower looper thread adjustment portion has a first member having a connecting portion of the spring and a second member having the thread locking portion, and the third input portion adjusts the relative distance between the first member and the second member along the intersecting direction.

3. The overedge sewing machine according to claim 2, characterized in that the third input unit has a screw shaft along the intersecting direction connecting the first member and the second member, and an operation input unit for rotating the screw shaft, and the operation input unit supports the screw shaft so that it can move along the intersecting direction.

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

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

6. An overedge sewing machine as described in claim 1, characterized in that it has a sewing type selection unit which, when a sewing type is selected, adjusts the 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.

7. An overedge sewing machine as claimed in claim 1, further comprising a thickness detection unit 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.

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

Images