Overcasting sewing machine

Abstract

To adjust thread delivery amount between an upper looper thread T3 and a lower looper thread T4 and individually adjust thread tension so that the upper looper thread T3 and the lower looper thread T4 do not restrict each other.SOLUTION: An overcasting sewing machine 100 comprises: a first input part 32 to move a needle thread adjusting part 24 along an intersection direction; a second input part 33 to interlock and move an upper looper thread adjusting part 25 and a lower looper thread adjusting part 26 along the intersection direction; an adjustment interlocking part 27 to interlock the upper looper thread adjusting part 25 and the lower looper thread adjusting part 26 during movement of the needle thread adjusting part 24; and a third input part 37 to input adjustment of relative positions along the intersection direction of a thread locking part 251 of the upper looper thread adjusting part 25 and a thread locking part 261 of the lower looper thread adjusting part 26 while allowing interlocking by the second input part 33 and the adjustment interlocking part 27.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to an overedge sewing machine. [Background technology]

[0002] In conventional overedge sewing machines, a preset amount of thread is let out from a thread supply source for each needle thread and looper thread for each stitch, thereby optimizing the thread tension of each thread while sewing. Furthermore, conventional overedge sewing machines automatically adjusted the amount of thread let-out for each thread depending on the stitch pitch, overedge width, and type of stitch selected, thereby optimizing the thread tension for each thread (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-272273 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional sewing machine described above has a structure in which various thread payout mechanisms are linked, and when the amount of thread payout from the needle thread is adjusted, the amount of thread payout from the looper thread is also adjusted accordingly. In this case, it is possible to reduce the burden of adjustment work compared to when adjustments are made for each thread separately, and it is convenient for users. However, adjustment of the amount of thread payout between the upper looper thread and the lower looper thread can only be performed in two stages by changing the pattern based on a structure in which the various thread payout mechanisms described above are linked, and it was not possible to meet requests such as wanting to change the texture of the stitches by arbitrarily adjusting the amount of thread payout between the upper looper thread and the lower looper thread.

[0005] An object of the present invention is to adjust the amount of yarn payout between the upper looper thread and the lower looper thread.

Means for Solving the Problem

[0006] In the overedge sewing machine, the present invention relates to a needle vertical movement mechanism that performs vertical movement of a sewing needle through which a needle thread passes, a lower looper mechanism including a lower looper for inserting a lower looper thread into a loop of the needle thread, an upper looper mechanism including an upper looper for inserting an upper looper thread into a loop of the lower looper thread, a feeding mechanism for feeding a workpiece to be sewn, An overedge sewing machine comprising a thread feeding mechanism that feeds 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 feeding mechanism has an upstream guide portion having an introduction portion for each thread through which the needle thread, the upper looper thread, and the lower looper thread are individually inserted, has a downstream guide portion having a lead-out portion for each thread through which the needle thread, the upper looper thread, and the lower looper thread are individually inserted, a drawing portion that reciprocates along the crossing direction with respect to the needle thread, the upper looper thread, and the lower looper thread passing from the introduction portion to the lead-out portion between the upstream guide portion and the downstream guide portion to draw out the needle thread, the upper looper thread, and the lower looper thread from their respective supply sources, has a thread locking portion that restrains the needle thread in the crossing direction, and varies the path of the needle thread passing from the introduction portion to the lead-out portion between the upstream guide portion and the downstream guide portion by moving along the crossing direction to adjust the drawing length of the needle thread by the drawing portion, has a thread locking portion that restrains the upper looper thread in the crossing direction, and varies the path of the upper looper thread passing from the introduction portion to the lead-out portion between the upstream guide portion and the downstream guide portion by moving along the crossing direction to adjust the drawing length of the upper looper thread by the drawing portion, It has a yarn locking part that restricts the lower looper yarn in the crossing direction, and between the upstream guide part and the downstream guide part, by moving along the crossing direction, it varies the path of the lower looper yarn that passes from the introduction part to the lead-out part, and adjusts the draw length of the lower looper yarn by the draw-out part. A first input part that moves the needle yarn adjustment part along the crossing direction. A second input part that moves the upper looper yarn adjustment part and the lower looper yarn adjustment part in conjunction along the crossing direction. An adjustment linkage part that links the upper looper yarn adjustment part and the lower looper yarn adjustment part when the needle yarn adjustment part moves. It is characterized by including a third input part that inputs the adjustment of the relative position along the crossing direction between the yarn locking part of the upper looper yarn adjustment part and the yarn locking part of the lower looper yarn adjustment part while allowing the linkage by the second input part and the adjustment linkage part.

Effect of the Invention

[0007] Due to the above configuration, the sewing machine of the present invention can adjust the amount of yarn fed out between the upper looper yarn and the lower looper yarn, and it is possible to individually adjust the yarn tension without the upper looper yarn and the lower looper yarn restricting each other.

Brief Explanation of the Drawings

[0008]

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Embodiments for Carrying Out the Invention

[0009] [Outline of an Edge Hemming Sewing Machine] Hereinafter, the edge hemming sewing machine 100 which is an embodiment of the present invention will be described in detail. FIG. 1 shows a perspective view of the edge hemming sewing machine 100. Hereinafter, the downstream side in the feeding direction of the workpiece to be sewn is referred to as "front", the upstream side in the feeding direction is referred to as "rear", the left hand side when facing the front is referred to as "left", the right hand side is referred to as "right", the vertically upward direction is referred to as "up", and the vertically downward direction is referred to as "down". The front-back direction, the left-right direction, and the up-down direction are orthogonal to each other. In the following description, it is assumed that the overedge sewing machine 100 is installed on a horizontal plane, and the front-back direction and the left-right direction are horizontal.

[0010] As the overedge sewing machine 100, a so-called lock sewing machine is exemplified. The overedge sewing machine 100 includes a sewing machine frame 110, a needle vertical movement mechanism that moves the sewing needle up and down, a lower looper mechanism having a lower looper for inserting a lower looper thread into the loop of the needle thread, an upper looper mechanism having an upper looper for inserting an upper looper thread into the loop of the lower looper thread, a feeding mechanism for feeding the workpiece to be sewn, a cutting mechanism for cutting the side end portion (for example, the right end portion) of the workpiece to be sewn to trim the sewing end portion, and a thread feeding mechanism 2 that feeds the needle thread, the lower looper thread, and the upper looper thread from the thread supply source in synchronization with each needle drop.

[0011] The sewing machine frame 110 houses or supports the entire configuration of the sewing machine. The sewing machine frame 110 has a bed portion 111 located at the lower part, a vertical cylinder portion 112 erected from the left side of the bed portion 111, and an arm portion 113 extending leftward from the upper part of the vertical cylinder portion 112. The upper surface of the left side of the bed portion 111 is horizontal and flat, and the sewing operation is performed with the workpiece to be sewn placed thereon. A needle plate 114 is provided on the upper surface of the left side of the bed portion 111 flush with the upper surface of the bed portion 111.

[0012] A thread stand device 120 is arranged on the front side of the arm portion 113. The overedge sewing machine 100 performs sewing using a maximum of four threads consisting of a needle thread T1, a needle thread T2, an upper looper thread T3, and a lower looper thread T4. The thread stand device 120 has four support shafts 121 to 124 that rotatably support thread bobbins that are the respective thread supply sources of the needle thread T1, the needle thread T2, the upper looper thread T3, and the lower looper thread T4. The support shafts 121 to 124 support the respective thread bobbins of the needle thread T1, the needle thread T2, the upper looper thread T3, and the lower looper thread T4 in order from the left. In the following description, the left needle thread T1 may be referred to as the left needle thread T1, and the right needle thread T2 may be referred to as the right needle thread T2.

[0013] Above the support shafts 121 to 124, a thread guiding member 125 is disposed, which has notch-shaped guiding portions for inserting the left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4, respectively. Each of the left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 is drawn out from a thread spool, passed through the respective guiding portions of the thread guiding member 125, and inserted into four thread guiding grooves 115 to 118 formed on the upper surface of the arm portion 113.

[0014] The needle vertical movement mechanism, the lower looper mechanism, the upper looper mechanism, the feeding mechanism, and the cutting mechanism are the same as those well-known in a lockstitch sewing machine, and thus detailed descriptions thereof are omitted. The needle vertical movement mechanism has a needle bar that holds a sewing needle passed through the needle thread at its lower end, and moves the needle bar vertically to perform needle penetration on the workpiece on the needle plate. The needle bar is disposed at the lower part near the left end of the arm portion 113. The needle bar can hold one or two sewing needles arranged side by side left and right, and the lockstitch sewing machine 100 can perform single-needle sewing and double-needle sewing. The left and right sewing needles may be referred to as the left needle and the right needle, respectively. The sewing machine 100 can perform single-needle sewing with only the left needle and single-needle sewing with 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 passed through the lower looper thread into the loop of the needle thread formed below the workpiece in synchronization with the descent of the sewing needle. In the case of double-needle sewing, the tip of the lower looper is simultaneously inserted into the loops of the two needle threads.

[0016] The upper looper mechanism inserts the tip of the upper looper passed through the upper looper thread into the loop of the lower looper formed below the workpiece in synchronization with the reciprocating movement of the lower looper. The upper looper mechanism further moves the upper looper forward from the right end of the needle plate to above the needle plate. Thereby, a sewing needle that descends into the loop of the upper looper thread sometimes formed during the retraction of the upper looper can be inserted. In the case of double-needle sewing, two sewing needles that descend into the loop of the upper looper thread are inserted simultaneously.

[0017] The hemming sewing machine 100 performs hemming by intertwining each thread through the cooperation of the needle vertical movement mechanism, the lower looper mechanism, and the upper looper mechanism. Note that the needle vertical movement mechanism, the lower looper mechanism, and the upper looper mechanism are all configured such that power is transmitted from the sewing machine motor through the power transmission mechanism, thereby realizing the synchronization of each mechanism.

[0018] The feeding mechanism is disposed within the bed portion 111 and feeds the workpiece by moving the feed teeth that can protrude and retract through the opening formed in the needle plate 114 forward. The movement operation of the feed teeth is imparted by the transmission mechanism using the sewing machine motor as the drive source. The transmission mechanism is composed of a cam mechanism, and by changing the direction of the power transmission body included in the cam mechanism, the sewing pitch (the feed amount of the workpiece per stitch), which is the feed length of the feed teeth, can be changed. The direction of the power transmission body can be changed by the rotational operation of the pitch adjustment knob 131, which is the sewing pitch setting input portion provided on the right side surface of the upright cylinder portion 112.

[0019] The cutting mechanism has a moving cutter that moves up and down at the right end portion of the needle plate 114, and cuts off the right end portion of the workpiece fed on the needle plate 114 in cooperation with the fixed cutter. The moving cutter is disposed behind the sewing needle and cuts off the workpiece immediately before the seam is formed. The vertical movement of the moving cutter also uses the sewing machine motor as the drive source. By cutting off the right end portion by the moving cutter, the workpiece can have a constant width for the distance from the needle drop position to the right end portion. In hemming, a seam is formed in which the upper looper thread and the lower looper thread cross from the right end portion of the workpiece to the needle drop position, and the distance from the needle drop position to the right end portion of the workpiece becomes the flare width (sewing width). The moving cutter can adjust the cutting position in the left-right direction by the rotational operation of the flare width adjustment knob 132, which is the flare width setting input portion. Adjusting the cutting position by this flare width adjustment knob 132 means the same thing as setting the flare width.

[0020] [Thread Pay-Out Mechanism: Schematic] FIG. 2 is a perspective view of the thread pay-out mechanism 2, and FIG. 3 is an exploded perspective view of the thread pay-out mechanism 2. The thread pay-out mechanism 2 includes 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 linkage portion 27, a stitch type selection portion 28, thread gripping portions 29 on the upstream and downstream sides, a gripping drive mechanism 30, a pay-out 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] [Thread Pay-Out Mechanism: Upstream Guide Plate and Downstream Guide Plate] As shown in FIG. 3, in the upper inner part of the arm portion 113, 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 are arranged in order from front to back. These upstream guide plate 21, first pull-out plate 23, upper looper thread adjustment plate 25, needle thread adjustment plate 24, lower looper thread adjustment plate 26, second pull-out plate 23, and downstream guide plate 22 are all flat plates, and each flat plate surface is inclined in a direction perpendicular to the rearward and downward diagonal direction.

[0022] In addition, 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, and the second pull-out plate 23 are each provided with a plurality of guide holes along the left-right direction at the lower part, and at least two of the four columns 215 standing vertically on the rear surface of the upstream guide plate 21 are passed through. Each support column 215 is formed with a flat upper part and a flat lower part, and the upper and lower flat surfaces are in sliding contact with the upper inner edge and the lower inner edge of the guide holes of each of 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, and the second drawer plate 23. Thereby, 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, and the second drawer plate 23 are all supported so as to be movable in the left - right direction with respect to the upstream guide plate 21. Also, between each of 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, a spacer (not shown) through which each support column 215 passes is inserted, and a predetermined gap is formed in the front - rear direction between the plates adjacent to each other in the front - rear direction.

[0023] At the tip ends of the four support columns 215, a downstream guide plate 22 having four insertion holes through which fastening members (such as screws, not shown) are inserted is fastened and fixed. Therefore, between the upstream guide plate 21 and the 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, and the second drawer plate 23 move in the left - right direction.

[0024] On the upper edge of the upstream guide plate 21, four thread introduction parts 211 - 214 are formed side - by - side in the left - right direction. Each of the introduction parts 211 - 214 is composed of a vertically long notch that is open upward at the upper edge of the upstream guide plate 21. Also, on the upper edge of the downstream guide plate 22, four thread lead - out parts 221 - 224 are formed side - by - side in the left - right direction. Each of the lead - out parts 221 - 224 is also composed of a vertically long notch that is open upward at the upper edge of the downstream guide plate 22. The four thread introduction parts 211 - 214 of the upstream guide plate 21 and the four thread lead - out parts 221 - 224 of the downstream guide plate 22 are respectively arranged immediately below the four thread guide grooves 115 - 118 formed on the upper surface of the aforementioned arm part 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 respectively inserted into the four thread guide grooves 115 to 118, they enter the introduction parts 211 to 214 and the lead-out parts 221 to 224 as they are. Accordingly, the left needle thread T1 can be in a state of being passed from the introduction part 211 to the lead-out part 221, the right needle thread T2 can be in a state of being passed from the introduction part 212 to the lead-out part 222, the upper looper thread T3 can be in a state of being passed from the introduction part 213 to the lead-out part 223, and the lower looper thread T4 can be in a state of being passed from the introduction part 214 to the lead-out part 224. The left needle thread T1, the right needle thread T2, the upper looper thread T3, and the lower looper thread T4 are each restricted in the left-right direction by the introduction parts 211 to 214 and the lead-out parts 221 to 224. Note that 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 on the rear side of the downstream guide plate 22.

[0026] [Thread Pay-Out Mechanism: Pull-Out Plate] The two pull-out plates 23 reciprocate along the crossing direction (for example, the left-right direction which is the orthogonal direction) with respect to the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 passing from the respective introduction parts 211 to 214 to the lead-out parts 221 to 224 between the upstream guide plate 21 and the downstream guide plate 22, and pull out the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 from their respective supply sources. The target value of the pay-out amount of each thread is equal to the length consumed by sewing for each stitch. Also, since the lengths consumed by each stitch of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 are different, the thread paths of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 passing between the upstream guide plate 21 and the downstream guide plate 22 are individually changed by the needle thread adjustment plate 24, the upper looper thread adjustment plate 25, and the lower looper thread adjustment plate 26, so that the pay-out amount by the pull-out plate 23 can be adjusted.

[0027] FIG. 4 is a perspective view seen from the direction in which the front side of the two pull-out plates 23 can be seen. The two drawer plates 23 are both of the same shape and are in the form of long strips along the left - right direction. And each drawer plate 23 has an extension part 235 formed at the right - hand part of the lower edge and extending downward. The two drawer plates 23 are connected by a fastening member such as a screw with a spacer (not shown) inserted between the extension parts 235 of each. The two drawer plates 23 are connected in a superposed state so that there is no shift when viewed from the direction perpendicular to the plate surface.

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

[0029] The drawer plate 23 is formed with insertion parts 231 - 234 through which the respective yarns T1 - T4 passing from the introduction parts 211 - 214 of the upstream guide plate 21 to the derivation parts 221 - 224 of the downstream guide plate 22 enter individually. Each of the insertion parts 231 - 234 is composed of a triangular notch and is open at the top. Each of the insertion parts 231 - 234 has contact parts 231a - 234a on its inner edge.

[0030] Fig. 5(A) shows the state before the needle yarns T1, T2 are drawn out by the drawer plate 23, Fig. 5(B) is a perspective view showing the state during drawing, and Fig. 6 is an explanatory view showing the yarn feeding due to the change in the yarn path. The front and rear drawer plates 23 are given a reciprocating motion of moving rightward and leftward with respect to the upstream guide plate 21 and the downstream guide plate 22 by a feeding drive mechanism 31 (described later). The rightward movement is the yarn drawing - out operation, and the leftward movement is the return operation of the drawer plate 23.

[0031] In the state just before drawing in Fig. 5(A), the needle yarns T1, T2 have a path in the shape of a single - peak that gently bulges to the right as shown by the colored lines in Fig. 6. Then, as shown in FIG. 5(B), when each extraction plate 23 moves to the right, the needle threads T1 and T2 change to a path in the shape of two peaks that bulge greatly to the right, as shown by the white line in FIG. 6. When each extraction plate 23 makes a return movement to the left, the increased length of the path during extraction becomes the feed length by each extraction plate 23. Note that the upper looper thread T3 and the lower looper thread T4 are also fed by the same operation.

[0032] [Thread feeding mechanism: Feeding drive mechanism] The feeding drive mechanism 31 will be described. FIG. 7 is a perspective view showing the front side of the upstream guide plate 21 provided with the feeding drive mechanism 31. As shown in the figure, the feeding drive mechanism 31 includes a drive shaft 311 rotatably supported on the front surface of the upstream guide plate 21, and a cylindrical cam 312 fixedly installed on the drive shaft 311.

[0033] The drive shaft 311 obtains power from the sewing machine motor and rotates in the same cycle as the vertical movement of the sewing needle. The drive shaft 311 is disposed along the left - right direction. The cylindrical cam 312 is fixed to the drive shaft 311 passing through its 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 extraction plate 23 described above projects from the front side of the upstream guide plate 21 through a long rectangular opening 216 formed in the upstream guide plate 21 in the left - right direction and fits into the cam groove 312a of the cylindrical cam 312. The cam groove 312a is formed in a shape that moves each extraction plate 23 to the right for extraction while the sewing needle is rising, and moves each extraction plate 23 to the left while the sewing needle is descending.

[0034] [Thread feeding mechanism: Each adjustment plate] As shown in Fig. 3, the needle thread adjusting plate 24 is disposed between the two drawer plates 23, and insertion portions 241 and 242 are formed through which the left needle thread T1 and the right needle thread T2 respectively enter, passing from the introduction portions 211 and 212 of the upstream guide plate 21 to the lead-out portions 221 and 222 of the downstream guide plate 22. Each of the insertion portions 241 and 242 is composed of a vertically long notch that is open upward at the upper edge of the needle thread adjusting plate 24. Each of the insertion portions 241 and 242 functions as a thread locking portion that restrains the left needle thread T1 and the right needle thread T2 in the left-right direction. Therefore, when the needle thread adjusting plate 24 is moved along the left-right direction, the left needle thread T1 and the right needle thread T2 can be brought closer in the left-right direction.

[0035] The upper looper thread adjusting plate 25 is disposed between the two drawer plates 23, and an insertion portion 251 is formed through which the upper looper thread T3 enters, passing from the introduction portion 213 of the upstream guide plate 21 to the lead-out portion 223 of the downstream guide plate 22. The insertion portion 251 is composed of 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, when the upper looper thread adjusting plate 25 is moved along the left-right direction, the upper looper thread T3 can be brought closer in the left-right direction.

[0036] The lower looper thread adjusting plate 26 is disposed between the two drawer plates 23, and an insertion portion 261 is formed through which the lower looper thread T4 enters, passing from the introduction portion 214 of the upstream guide plate 21 to the lead-out portion 224 of the downstream guide plate 22. The insertion portion 261 is composed of 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, when the lower looper thread adjusting plate 26 is moved along the left-right direction, the lower looper thread T4 can be brought closer in the left-right direction.

[0037] Further, as shown in Fig. 3, the lower loop thread adjusting plate 26 is integrally formed by overlapping 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 long holes 264c along the left - right direction are provided in the second member 264. The first member 263 and the second member 264 are connected by two step screws 265. The step screws 265 pass through the two long 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 is formed with the above - mentioned guide holes and is supported by the support column 215 so as to be movable in the left - right direction. Further, the first member 263 has a leg portion 262 (connecting portion) extending downward, and similarly, it is connected by a leg portion 252 (connecting portion) extending downward from the upper loop thread adjusting plate 25 and a spring 332 described later (see Fig. 11). On the other hand, the second member 264 is formed with an insertion portion 261 through which the lower loop thread T4 is inserted. Therefore, the lower loop thread adjusting plate 26 moves in conjunction with the upper loop thread adjusting plate 25 in the left - right direction by the spring 332, and the relative position in the left - right direction between the insertion portion 251 and the insertion portion 261 can be adjusted by the movement of the second member 264 relative to the first member 263.

[0039] Between the first member 263 and the second member 264, a third input portion 37 is provided for inputting the adjustment of the mutual distance along the left - right direction between the insertion portion 251 of the upper loop thread adjusting plate 25 and the insertion portion 261 of the lower loop thread adjusting plate 26 while allowing the interlocking by the second input portion 33 and the adjustment interlocking portion 27. The third input portion 37 has a function of adjusting and holding the relative position in the left - right direction between the first member 263 and the second member 264. Details of this third input portion 37 will be described later.

[0040] The functions of the adjusting plates 24 - 26 will be described with reference to Fig. 6 mentioned above. Here, the needle threads T1, T2 will be taken as examples for explanation. The needle thread adjustment plate 24 can lock the middle part on the path of the needle threads T1 and T2 by the insertion parts 241 and 242 and move it in the left - right direction. For example, when the insertion parts 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 direction opposite to the pulling - out direction (rightward) by the two pull - out plates 23 (leftward), the amplitudes of the two peaks during the pulling - out by the two pull - out plates 23 increase, so more pulling - outs can be performed. In this way, each of the adjustment plates 24 - 26 can move the middle point M of each of the threads T1 - T4 left - right by the insertion parts 241, 242, 251, 261 by moving left - right, and thereby adjust the feeding length of the threads by the two pull - out plates 23.

[0041] [Thread Feeding Mechanism: Thread Gripping Part] When feeding each of the threads T1 - T4 by the two pull - out plates 23, it is necessary to properly pull from the thread supply source side and not pull back the thread from the thread consumption side. For this reason, an upstream thread gripping part 29 is provided on the front surface of the upstream guide plate 21 on the thread supply source side, and a downstream thread gripping part 29 is provided on the rear surface of the downstream guide plate 22 on the thread consumption side.

[0042] Fig. 8 is a perspective view of the upstream and downstream thread gripping parts 29. Here, since the configurations of the upstream thread gripping part 29 and the downstream thread gripping part 29 are the same, mainly the downstream thread gripping part 29 will be described.

[0043] The downstream thread gripping portion 29 includes four fixing plates 291 individually and fixedly attached to one side (e.g., the left side) of each of the lead-out portions 221 to 224 on the rear surface of the downstream guide plate 22, four gripping plates 292 disposed opposite to each fixing plate 291 in a configuration sandwiching the lead-out portions 221 to 224 when viewed from a 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 gripping plate 292 toward the corresponding fixing plate 291, and a support plate 295 that supports the right end portion of the support rod 293 and serves as a spring receiver for the rightmost spring 294.

[0044] Each fixing plate 291 is erected on the rear surface of the downstream guide plate 22 such that the opposing surface to the gripping plate 292 is along the left inner edge portions of the lead-out portions 221 to 224. In the case of the upstream thread gripping portion 29, each fixing plate 291 is erected on the front surface of the upstream guide plate 21 along the left inner edge portions of the introduction portions 211 to 214.

[0045] The erected plate surface of each fixing plate 291 is perpendicular to the downstream guide plate 22. A through-hole is provided at the central portion of the plate surface of each fixing plate 291, and the support rod 293 is simultaneously inserted therethrough. Each fixing plate 291 has a function of gripping each of the threads T1 to T4 in cooperation with each gripping plate 292 and a function of supporting the support rod 293 so as to be movable in the left-right direction. Further, each fixing plate 291 functions as a spring receiver when the right end portion of the spring 294 that presses the adjacent gripping plate 292 to the left is in pressure contact therewith.

[0046] Also, the support plate 295 is made of the same member as the fixing plate 291, and the right end portion of the support rod 293 is inserted therethrough. Further, the support plate 295 functions as a spring receiver when the right end portion of the rightmost spring 294 is in pressure contact therewith. Note that the support plate 295 does not have a function of gripping the thread since there is no opposing gripping plate 292. Note that the support plate 295 does not have to be made of the same member as the fixing plate 291 as long as it has a function of inserting the right end portion of the support rod 293 and pressing the right end portion of the rightmost spring 294.

[0047] Each gripping plate 292 is circular, and the support rod 293 penetrates the center portion simultaneously. Each gripping plate 292 is pressed toward the fixed plate 291 by a spring 294 from the surface on the opposite side of the opposing surface of each fixed plate 291. Each spring 294 is a coil spring, and the support rod 293 is inserted therethrough. The left end of each spring 294 is in pressure contact with each gripping plate 292, and the right end is in pressure contact with the left surface of the adjacent fixed plate 291 on the right. Thereby, each spring 294 is supported by the adjacent fixed plate 291 on the right and presses each gripping plate 292 to the left.

[0048] The support rod 293 has a structure that restricts each gripping plate 292 from moving leftward beyond a predetermined support position and allows it to move rightward beyond the predetermined support position. This restricting structure consists of, for example, a structure that locks each gripping plate 292 from the left with a diameter-expanded portion or a protruding portion protruding radially outward on the support rod 293. Since the support rod 293 has the above-described restricting structure, when the support rod 293 is moved rightward, each gripping plate 292 can also be moved rightward. Thereby, by moving the support rod 293 rightward, each of the yarns T1 to T4 gripped by each gripping plate 292 can be released.

[0049] [Yarn Pay-Out Mechanism: Gripping Drive Mechanism] FIG. 9 is a perspective view of the gripping drive mechanism 30. The upstream yarn gripping portion 29 and the downstream yarn gripping portion 29 need to grip and release each of the yarns T1 to T4 at appropriate timings, respectively. That is, when the pull-out plate 23 is pulled out as described above, the upstream yarn gripping portion 29 is in a released state and the downstream yarn gripping portion 29 is in a gripping state, and when the pull-out plate 23 moves back, the upstream yarn gripping portion 29 is in a gripping state and the downstream yarn gripping portion 29 is in a released state.

[0050] The gripping drive mechanism 30 shares the drive shaft 311 of the above-described pay-out drive mechanism 31 as a drive shaft. The holding drive mechanism 30 includes an end face cam 301 provided at the left end of the drive shaft 311, an upstream follower (not shown) composed of a roller that abuts on the rear side region RA (see FIG. 10) of the cam surface of the end face cam 301, an upstream operating arm 302 that holds the upstream follower and performs a swinging motion, a downstream follower (not shown) composed of a roller that abuts on the front side region FA (see FIG. 10) of the cam surface of the end face cam 301, 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 thread holding portion 29 to the right.

[0051] FIG. 10 is a perspective view of the end face cam 301. The end face cam 301 rotates about the left-right direction as the axis by the drive shaft 311. And the outer peripheral periphery of the left face of the end face cam 301 is the cam surface 301a. The cam surface 301a has irregularities in the left-right direction formed at predetermined positions on the circumference. As shown in the figure, generally the rear portion of the cam surface 301a is the rear side region RA where the upstream follower abuts, and generally the front portion of the cam surface 301a is the front side region FA where the downstream follower abuts. In this way, by obtaining power at two different 180° positions on the circumference of a single end face cam 301, the upstream thread holding portion 29 and the downstream thread holding portion 29 can be alternately operated at timings shifted by half a cycle in the rotation cycle of the drive shaft 311.

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

[0053] The upstream actuating arm 302 has a lower portion than the connecting cylinder portion 305 holding the upstream slave joint body, and a swinging motion in the left-right direction is input from the end face cam 301. Further, the upper portion of the upstream actuating arm 302 above the connecting cylinder portion 305 can swing and push the left end portion of the support rod 293 of the upstream yarn gripping portion 29 to the right.

[0054] The downstream input arm 303 is fixedly connected to the front end portion of a connecting shaft 306 rotatably supported inside the connecting cylinder portion 305, and performs a swinging motion 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 portion is fixedly connected to the lower end portion of the downstream output arm 304 on the rear surface side of the downstream guide plate 22. The downstream input arm 303 receives a swinging motion in the left-right direction from the end face cam 301 through the downstream slave joint body. The downstream output arm 304 swings together with the downstream input arm 303 via the connecting shaft 306, and can push the left end portion of the support rod 293 of the downstream yarn gripping portion 29 to the right.

[0055] Note that the cam surface 301a of the end face cam 301 is configured to push the support rod 293 of the upstream yarn gripping portion 29 to the right while the sewing needle is rising, release each yarn T1 - T4 from the gripping state, and keep the downstream yarn gripping portion 29 in the gripping state. Furthermore, the cam surface 301a of the end face cam 301 is configured to push the support rod 293 of the downstream yarn gripping portion 29 to the right while the sewing needle is descending, release each yarn T1 - T4 from the gripping state, and keep the upstream yarn gripping portion 29 in the gripping state.

[0056] Thereby, the gripping drive mechanism 30 can be operated such that in synchronization with the left - right movement of the two pull - out plates 23, when the pull - out plates 23 are pulled out, the upstream yarn gripping portion 29 is in the released state and the downstream yarn gripping portion 29 is in the gripping state, and when the pull - out plates 23 return, the upstream yarn gripping portion 29 is in the gripping state and the downstream yarn gripping portion 29 is in the released state.

[0057] [Yarn feeding mechanism: First input part] FIG. 11 is a view of the structure supported on the rear side of the upstream guide plate 21 as seen from the rear side. The first input unit 32 is intended to interlock the pitch adjustment knob 131, which is a setting input unit for the sewing pitch, and the needle thread adjustment plate 24. That is, when the pitch adjustment knob 131 is operated in the direction in which the sewing pitch increases, the first input unit 32 interlocks the needle thread adjustment plate 24 in the direction in which the feeding amounts of the left and right needle threads T1 and T2 increase. As shown in FIGS. 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 at the lower part of the rear surface of the upstream guide plate 21, a transmission lever 323 provided at 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 direction in FIG. 11). Further, the first input unit 32 includes guides or pulleys (not shown) arranged at various positions on the path of the first operation wire 321 from the pitch adjustment knob 131 to the guide pulley 322.

[0058] One end of the first operation wire 321 is connected to the pitch adjustment knob 131 or a member that rotates integrally with the pitch adjustment knob 131, and increases or decreases the tension in response to the setting input operation of the sewing pitch by the pitch adjustment knob 131 and inputs it to the lower end of the transmission lever 323. Note that the other end of the first operation wire 321 extends downward, changes its direction to the left via the guide pulley 322, and is connected to the lower end of the guide pulley 322 from the right side.

[0059] The transmission lever 323 is long along the vertical direction and is rotatably supported at an intermediate portion in the vertical direction by a support shaft erected vertically from the upstream guide plate 21. The lower end of the transmission lever 323 is connected to the first operation wire 321 from the right side, and the tension to the right is input from the first operation wire 321.

[0060] An intermediate portion of the transmission lever 323 in the vertical direction has a branch portion 323a extending leftward, and one end of the return spring 324 described above is connected to the branch portion 323a. The return spring 324 applies an upward tension to the branch portion 323a and biases the transmission lever 323 to rotate in a direction against the tension received from the first operation 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. Thus, when the transmission lever 323 rotates, the needle thread adjustment plate 24 moves in the left - right direction. Therefore, when the stitch pitch is set and input by the pitch adjustment knob 131, the needle thread adjustment plate 24 can be interlocked in the left - right direction through the first operation wire 321 and the transmission lever 323. Also, the return spring 324 always biases the needle thread adjustment plate 24 to the right.

[0062] [Thread feeding mechanism: Second input part] The second input part 33 aims to interlock the gathering width adjustment knob 132, which is a gathering width setting input part, with the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26. That is, when the gathering width adjustment knob 132 is operated in the direction of increasing the gathering width, the second input part 33 interlocks the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 in the direction of increasing the feeding amount of the upper looper thread T3 and the lower looper thread T4. As shown in FIGS. 1, 3, and 11, the second input part 33 has a second operation wire 331 with one end connected to the gathering width adjustment knob 132 and the other end connected to the upper looper thread adjustment plate 25, a spring 332 for interlocking the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26, and a return spring 333 for biasing the upper looper thread adjustment plate 25 to the right. Also, the second input part 33 includes guides or pulleys (not shown) arranged at various positions on the path of the second operation wire 331 from the gathering 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 loop thread adjusting plate 26 has the first member 263 and the second member 264 in a state where their relative positions in the left-right direction are maintained.

[0063] One end of the second operation wire 331 is connected to the hooking width adjusting knob 132 or a member that rotates integrally with the hooking width adjusting knob 132, and the tension is increased or decreased according to the setting input operation of the hooking width by the hooking width adjusting knob 132 and input to the upper loop thread adjusting plate 25. Note that the other end of the second operation wire 331 extends downward, changes its direction to the right via the movable pulley 273 of the adjustment interlocking portion 27 described later, and is connected to the upper loop thread adjusting plate 25 from the left side.

[0064] The spring 332 is a tension spring that connects the leg portion 252 extending downward from the lower end portion of the upper loop thread adjusting plate 25 and the leg portion 262 extending downward from the lower end portion of the lower loop thread adjusting plate 26. The upper loop thread adjusting plate 25 is disposed to the left of the lower loop thread adjusting plate 26, and in a state where this arrangement order is maintained, the upper loop thread adjusting plate 25 and the lower loop thread adjusting plate 26 are maintained in a state of being close to each other by the spring 332. Further, since they are connected by the spring 332, the upper loop thread adjusting plate 25 and the lower loop thread adjusting plate 26 can be moved while maintaining a certain interval in the left-right direction in principle.

[0065] The right end portion of the upper loop thread adjusting plate 25 has an arm portion 253 extending to the right, and the left end portion of the above-described return spring 333 is connected to the arm portion 253. The right end portion of the return spring 333 is connected to the right end portion of the downstream guide plate 22, applies a tension to the right to the upper loop thread adjusting plate 25 through the arm portion 253, and applies a tension in a direction to resist the leftward tension received by the upper loop thread adjusting plate 25 from the second operation wire 331.

[0066] [Thread Pay-Out Mechanism: Adjustment Interlocking Portion] The adjustment linkage 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 operation wire 331. That is, when the needle thread adjusting plate 24 moves in the direction in which the feed amounts of the respective needle threads T1, T2 increase, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are also interlocked in the direction in which the feed amounts of the upper looper thread T3 and the lower looper T4 increase. As shown in FIGS. 3 and 11, the adjustment linkage 27 includes a linkage plate 271 that moves in the left-right direction 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 linkage plate 271, and a movable pulley 273 disposed in the cam hole 271a of the linkage plate 271.

[0067] The linkage plate 271 has, at its upper end, two long holes through which two of the four columns 215 standing rearward from the upstream guide plate 21 are inserted, and is disposed between the front pull-out plate 23 and the needle thread adjusting plate 24 in a state of being supported so as to be movable in the left-right direction. The linkage plate 271 has a downward extension portion extending downward at its lower right portion, and has an arm portion extending leftward at the left edge portion of the downward extension portion. The right end portion of the connecting link 272 is rotatably connected to the arm portion. Also, the left end portion of the connecting link 272 is rotatably connected to the right corner portion near the upper end portion of the transmission lever 323 of the first input unit 32. Thereby, when the transmission lever 323 of the first input unit 32 rotates, the needle thread adjusting plate 24 and the linkage plate 271 can be moved in the same direction.

[0068] Further, a cam hole 271a is formed through the downward extension portion of the linkage plate 271. The cam hole 271a has a certain length in the vertical direction and also has a certain width in the horizontal direction. The rotation axis of the movable pulley 273 is passed from front to rear, and the movable pulley 273 is disposed on the rear surface side of the linkage plate 271. The movable pulley 273 can mainly move up and down and can move slightly back and forth within the range allowed by the cam hole 271a. Note that the rotating shaft of the movable pulley 273 is supported on the front side of the interlocking plate 271 at the upper end of the 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 downward is wound around the movable pulley 273. The second operation wire 331 is connected to the upper loop thread adjustment plate 25 from the left after changing its direction to the right by the movable pulley 273. Therefore, when the interlocking plate 271 moves to the left together with the needle thread adjustment plate 24, the upper loop thread adjustment plate 25 and the lower loop thread adjustment plate 26 connected by the spring 332 can be interlockingly moved to the left via the movable pulley 273 and the second operation wire 331. Also, when the interlocking plate 271 moves to the right together with the needle thread adjustment plate 24, the second operation wire 331 becomes slack, and the upper loop thread adjustment plate 25 and the lower loop thread adjustment plate 26 can be interlockingly moved to the right by the tension of the return spring 333.

[0070] [Thread feeding mechanism: Stitch type selection unit] When the thread feeding mechanism 2 selects the type of stitch, it has a stitch type selection unit 28 that adjusts each of the threads T1 to T4 to be fed out at an appropriate thread feeding amount individually according to the selected stitch type. The types of stitches that can be selected by the stitch type selection unit 28 are: (1) double needle edge hemming stitch (double needle lock stitch), (2) single needle edge hemming stitch (single needle lock stitch), (3) single needle narrow edge hemming stitch (single needle narrow lock stitch), and (4) single needle winding stitch (single needle winding lock stitch).

[0071] As shown in FIG. 11, the stitch type selection unit 28 includes 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 link 284 that support the movable pulley 273 described above, a separating member 285 that moves the upper loop thread adjustment plate 25 and the lower loop thread adjustment plate 26 apart, a base end link 286 and a tip link 287 that support the separating member 285, and a lock spring 288 that holds the cam plate 281 at 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 four openings are formed side by side in the left-right direction. The first and third openings from the left among them are linear along the left-right direction, and are support holes into which columns 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 so as to be slidable in the left-right direction by these two support holes.

[0073] Also, the second and fourth openings from the left of the cam plate 281 are cam holes 281a and 281b related to the movement of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26. The actions of these cam holes 281a and 281b will be described later.

[0074] The sewing type switching knob 282 is cylindrical and is supported by the upstream guide plate 21 so as to be rotatable about an axis along the left-right direction. The outer peripheral surface of the sewing type switching knob 282 is disposed in proximity and opposition to the front surface of the right end portion of the cam plate 281. A spiral cam groove 282a is formed on the outer peripheral surface of the sewing type switching knob 282 (see FIG. 12), and a pin 281c that fits into the spiral cam groove 282a is erected on the front side of the front surface of the right end portion of the opposing cam plate 281. Therefore, when a rotational operation is applied to the sewing type switching knob 282, the pin 281c is guided into the spiral cam groove 282a, and the cam plate 281 can be moved left and right.

[0075] Also, four wedge-shaped notches 281d are formed side by side at the lower end portion of the cam plate 281. The tip portions of a lock spring 288 composed of a leaf spring having a tip wedge-shaped convex portion supported by the lower part of the rear surface of the upstream guide plate 21 are fitted into any of the notches 281d according to the position of the cam plate 281. That is, four notches 281d are arranged so that the cam plate 281 can be positioned according to each of the four selected sewing types along the sewing type selection unit 28, and can be held in each position by the lock spring 288.

[0076] The base link 283 and the tip link 284 that support the movable pulley 273 are rotatably connected to each other, and the base end portion of the base link 283 is rotatably supported by the left support column that supports the cam plate 281. Also, as described above, the tip end portion of the tip link 284 supports the movable pulley 273 through the cam hole 271a of the interlocking plate 271. Furthermore, a pin 283a that protrudes rearward is provided at the connecting portion between the base link 283 and the tip link 284, and it is fitted into the cam hole 281a on the left side of the cam plate 281. In the case of this configuration, with respect to the lateral movement of the cam plate 281, the pin 283a moves up and down, and through the tip link 284, the movable pulley 273 can also be moved up and down.

[0077] The separation member 285 is supported at the tip end portions of the base link 286 and the tip link 287 in a state of being inserted between the leg portion 252 of the upper looper thread adjusting plate 25 and the leg portion 262 of the first member 263 of the lower looper thread adjusting plate 26 that are adjacent to each other. The separation member 285 is cylindrical, and by moving upward, it can be separated left and right so as to push apart the leg portion 252 and the leg portion 262.

[0078] The tip end portion of the tip link 287 supports the separation member 285. Furthermore, a pin 286a that protrudes rearward is provided at the connecting portion between the base link 286 and the tip link 287, and it is fitted into the cam hole 281b on the right side of the cam plate 281. In the case of this configuration, with respect to the lateral movement of the cam plate 281, the pin 286a moves up and down, and through the tip link 287, the separation member 285 can also be moved up and down.

[0079] The change in the feed amount of each thread T1 to T4 due to the selection of the sewing type in the sewing type selection unit 28 will be described. FIG. 11 shows the operating state of the stitch type selection unit 28 when (1) double-needle edge hemming stitch (double-needle lock stitch) is selected, FIG. 12 shows the operating state of the stitch type selection unit 28 when (2) single-needle edge hemming stitch (single-needle lock stitch) is selected, FIG. 13 shows the operating state of the stitch type selection unit 28 when (3) single-needle narrow edge hemming stitch (single-needle narrow lock stitch) is selected, and FIG. 14 shows the operating state of the stitch type selection unit 28 when (4) single-needle winding stitch (single-needle winding lock stitch) is selected. The operating state of the stitch type selection unit 28 when (1) double-needle edge hemming stitch (double-needle lock stitch) in FIG. 11 is selected will be described assuming that each thread T1 to T4 is fed out at a reference value.

[0080] In the case of (1) double-needle edge hemming stitch in FIG. 11, the cam plate 281 reaches the leftmost position by operating the stitch type switching knob 282. In this case, within the left cam hole 281a, the pin 283a is located at the uppermost position. Note that the height of the pin 283a changes in three stages of "upper", "middle", and "lower" within the cam hole 281a (the same applies to the movable pulley 273). In FIG. 11, the pin 283a and the movable pulley 273 are in the "upper" position.

[0081] On the other hand, within the right cam hole 281b, the pin 286a is located at the lowermost position. Note that the height of the pin 286a changes in two stages of "upper" and "lower" within the cam hole 281b (the same applies to the spacer member 285). In FIG. 11, the pin 286a and the spacer member 285 are in the "lower" position.

[0082] In the case of (2) single-needle edge hemming stitch in FIG. 12, the left sewing needle is removed and the left needle thread T1 is not used. Then, the cam plate 281 moves to the second position from the left by operating the stitch type switching knob 282. In this case, within the left cam hole 281a, the pin 283a descends, and the pin 283a and the movable pulley 273 assume a state of being positioned at "middle". Due to the descent of the movable pulley 273, the second operation wire 331 becomes slack, 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 rightward. In this case, the payout amounts of the upper looper thread T3 and the lower looper thread T4 decrease from the reference amount. Since the needle thread adjusting plate 24 does not move, the right needle thread T2 maintains the payout amount at the reference value. In the case of single-needle edge hemming stitch using the left sewing needle not being used, the left and right width of the stitch is narrower than that of double-needle edge hemming stitch, so the consumption amounts of the upper looper thread T3 and the lower looper thread T4 decrease.

[0083] On the other hand, within the right cam hole 281b, the pin 286a and the spacer member 285 maintain the position of "down". In the case of single-needle edge hemming stitch, 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 narrow edge hemming stitch (single-needle narrow lock stitch) in (3) of FIG. 13, the left sewing needle is removed and the left needle thread T1 is not used. Then, by operating the stitch changeover knob 282, the cam plate 281 moves to the third position from the left. In this case, within the left cam hole 281a, the pin 283a descends, and the pin 283a and the movable pulley 273 assume a state of being positioned at "down". Due to the descent of the movable pulley 273, the second operation wire 331 becomes slack, 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 rightward. In this case, the payout amounts of the upper looper thread T3 and the lower looper thread T4 decrease further compared to the case of FIG. 12. In the case of single-needle narrow edge hemming stitch, the edge width on the left and right of the stitch is narrower than that of single-needle edge hemming stitch, so the consumption amounts of the upper looper thread T3 and the lower looper thread T4 decrease further.

[0085] On the other hand, within the right cam hole 281b, the pin 286a and the spacer member 285 maintain the position of "down". In the case of single-needle narrow hem stitching, the relative ratio of the consumption amounts of the upper looper thread T3 and the lower looper thread T4 does not vary.

[0086] In the case of the single-needle winding stitch (single-needle winding lock stitch) of (4) in FIG. 14, the left sewing needle is removed and the left needle thread T1 is not used. Also, in the winding stitch, the hemming stitch is performed in a state where the right end portion of the workpiece to be sewn is bent to the left by a specified width and overlapped (wound state). As shown in FIG. 14, by operating the stitch changeover knob 282, the cam plate 281 moves to the rightmost position. In this case, within the left cam hole 281a, the pin 283a rises, and the pin 283a and the movable pulley 273 are in a state of being positioned at "middle". Due to the rise of the movable pulley 273, the second operation wire 331 generates tension, and the upper looper thread adjusting plate 25 moves further to the left than in the case of (3) single-needle narrow hem stitching.

[0087] On the other hand, within the right cam hole 281b, the pin 286a and the spacer member 285 rise to the "upper" position. As a result, the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 are separated left and right. Also, the lower looper thread adjusting plate 26 moves to the right, and the feeding amount of the lower looper thread T4 decreases. In the case of single-needle winding stitch, since the stitch is formed so as to wind the right end portion of the workpiece overlapped with the upper looper thread T3, the consumption amount of the upper looper thread T3 becomes larger than that of the lower looper thread T4.

[0088] Note that the needle thread adjusting plate 24 does not move due to the above-described position switching (1) to (4) of the cam plate 281 by operating the stitch changeover knob 282, and the feeding amounts of the needle threads T1 and T2 do not vary.

[0089] [Thickness detection unit] The purpose of the thickness detection unit 35 is to adjust the feeding amounts of the respective threads T1 to T4 according to the thickness of the workpiece on the needle plate 114. As shown in FIG. 2, the thickness detection unit 35 includes a thickness detection lever 351 as a thickness detection member that rotates in conjunction with the vertical movement of a presser foot (not shown) that presses the workpiece from above on the needle plate 114, a support link 352 that rotates together with the thickness detection lever 351, and a pulley 353 rotatably supported at the rotating end of the support link 352.

[0090] The left end of the thickness detection lever 351 is installed so as to rotate left and right by a link (not shown) that interlocks with the presser bar, and is biased to the left by the tension of the first operation wire 321. When the thickness of the workpiece on the needle plate increases, the left end moves to the left. The support link 352 supports the pulley 353 at its lower end and rotates in the same direction as the rotation direction of the thickness detection lever 351. That is, when the left end of the thickness detection lever 351 moves to the left, the lower end of the support link 352 rotates to the left. The pulley 353 is arranged so as to contact the middle part of the first operation wire 321 from the lower side (pitch adjustment knob 131) to the guide pulley 322 of the first input unit 32 from the right side.

[0091] With the above configuration, as the thickness of the workpiece increases, the pulley 353 moves to the left, so the middle part of the first operation wire 321 from the lower side to the guide pulley 322 of the first input unit 32 is pulled to the left by the pulley 353 that contacts from the right side. As a result, the tension of the first operation wire 321 increases, the transmission lever 323 of the first input unit 32 rotates, and the needle thread adjustment plate 24 is moved to the left. Further, when the transmission lever 323 rotates, the adjustment interlocking unit 27 also moves the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 to the left. Therefore, when the workpiece is thick, the feeding amount of each thread T1 to T4 can be increased, and when the workpiece is thin, the feeding amount of each thread T1 to T4 can be decreased.

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

[0093] The loop thread tension adjustment knob 361 inputs the increase or decrease of the thread tensions of the upper loop thread T3 and the lower loop thread T4 by a rotational operation. The loop thread tension adjustment knob 361 is provided with a mechanism for holding the position where the rotational operation is performed, for example, by a latch mechanism (not shown). The support link 362 is pivotally supported at its lower end portion so as to be rotatable, and its upper end portion performs a rotational operation. The upper end portion of the support link 362 is connected to a member that rotates integrally with the loop thread tension adjustment knob 361 or the loop thread tension adjustment knob 361, and rotates in conjunction with the loop thread tension adjustment knob 361 in the same direction.

[0094] The pulley 363 provided at the lower end portion of the support link 362 is arranged to contact, for example, the middle portion of the second operation wire 331 from the lower (hem width adjustment knob 132) to the movable pulley 273 of the adjustment interlocking portion 27 from the left side. Also, the pulley 364 provided at the upper end portion of the support link 362 is arranged to contact, for example, the middle portion of the second operation wire 331 from the right side immediately above the pulley 363.

[0095] With the above configuration, for example, when the loop thread tension adjustment knob 361 is rotated counterclockwise in FIG. 2, the middle portion of the second operation wire 331 is manually pulled leftward with the upper pulley 364 contacting the lower pulley 363 from the right side. As a result, the second operation wire 331 generates tension and moves the upper loop thread adjustment plate 25 and the lower loop thread adjustment plate 26 leftward. As a result, the feeding amounts of the upper looper thread T3 and the lower looper thread T4 increase, and the thread tensions of the upper looper thread T3 and the lower looper thread T4 during sewing are reduced.

[0096] Also, when the looper thread tension adjusting knob 361 is rotated in the clockwise direction in FIG. 2, the middle part of the second operation wire 331 causes the upper pulley 364 to move to the right with respect to the lower pulley 363, reducing the amount of manual feeding. As a result, the tension of the second operation wire 331 is reduced, moving the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 to the right. Thereby, the feeding amounts of the upper looper thread T3 and the lower looper thread T4 decrease, and the thread tensions of the upper looper thread T3 and the lower looper thread T4 during sewing increase.

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

[0098] [Adjustment input unit] When the adjustment input unit 34 moves the needle thread adjusting plate 24 by manually feeding the middle part of the first operation wire 321 to adjust the thread tensions of the needle threads T1 and T2, the middle part of the second operation wire 331 is also manually fed to suppress or reduce the interlocking of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 accompanying the movement of the needle thread adjusting plate 24 by the adjustment interlocking unit 27.

[0099] FIG. 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 manually feeds the middle part of the first operation wire 321 from the lower part (pitch adjustment knob 131) to the guide pulley 322 of the first input unit 32, and the middle part of the second operation wire 331 from the lower part (slant width adjustment knob 132) to the movable pulley 273 of the adjustment interlocking unit 27 to adjust the thread tensions of the needle threads T1 and T2.

[0100] The adjustment input unit 34 includes a pair of first abutting pulleys 341 that abut against an intermediate portion of the first operation wire 321 from one side (for example, the rear side), a pair of second abutting pulleys 342 that abut against an intermediate portion of the second operation wire 331 from one side (for example, the rear side), a first pulling pulley 343 that semi-winds a loop of the first operation wire 321 drawn from between the pair of first abutting pulleys 341, a second pulling pulley 344 that semi-winds a loop of the second operation wire 331 drawn from between the pair of second abutting pulleys 342, a support link 345 that supports the first pulling pulley 343 and the second pulling 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 operation to the support link 345, and a needle thread tension adjusting knob 348 that is provided vertically movably on the rear cover of the overedge sewing machine 100.

[0101] The pair of first abutting pulleys 341 are arranged vertically with a certain interval therebetween, and the first operation wire 321 is drawn out in a loop shape so as to detour rearward from between the two first abutting pulleys 341. And this loop-shaped first operation wire 321 is semi-wound in a range that is approximately a half circumference on the rear side of the first pulling pulley 343 arranged behind the pair of first abutting pulleys 341. In this state, if the first pulling pulley 343 moves rearward, the first operation wire 321 is pulled out excessively, so on the downstream side of the first operation wire 321, the tension increases. If the first pulling pulley 343 moves forward, the amount of the first operation wire 321 pulled out is reduced, and on the downstream side of the first operation wire 321, the tension is also reduced.

[0102] The pair of second abutting pulleys 342 are arranged vertically with a certain interval therebetween, and the second operation wire 331 is drawn out in a loop shape so as to detour rearward from between the two second abutting pulleys 342. And this loop-shaped second operation wire 331 is semi-wound in a range that is approximately a half circumference on the rear side of the second pulling pulley 344 arranged behind the pair of second abutting pulleys 342. If the second extraction pulley 344 moves rearward in this state, the second operation wire 331 will be pulled out excessively. Therefore, on the downstream side of the second operation wire 331, the tension increases. If the second extraction pulley 344 moves forward, the amount of wire pulled out from the second operation wire 331 will decrease, and on the downstream side of the second operation wire 331, the tension will also decrease.

[0103] The first contact pulley 341 and the second contact pulley 342 are rotatably supported by an axis along the left - right direction by a support bracket 346. The first extraction pulley 343 and the second extraction pulley 344 are rotatably supported by an axis along the left - right direction by a support link 345. And the support link 345 is generally long in the up - down direction, supports the second extraction pulley 344 at its upper end, and supports the first extraction pulley 343 at its middle part. Further, the support link 345 is rotatably supported by the support bracket 346 through a support shaft 346a along the left - right direction between the first extraction pulley 343 and the second extraction pulley 344. Furthermore, the support link 345 is disposed behind a pair of the first contact pulleys 341 and a pair of the second contact pulleys 342 supported by the support bracket 346.

[0104] In the case of this configuration, for example, when the support link 345 rotates in the clockwise direction in FIG. 15, as shown by the two white arrows, the first extraction pulley 343 moves away from the pair of first contact pulleys 341, and the second extraction pulley 344 approaches the pair of second contact pulleys 342. That is, the tension of the first operation wire 321 increases, and the tension of the second operation wire 331 decreases. Also, when the support link 345 rotates in the counter - clockwise direction in FIG. 15, as shown by the two black arrows, the first extraction pulley 343 approaches the pair of first contact pulleys 341, and the second extraction pulley 344 moves away from the pair of second contact pulleys 342. That is, the tension of the first operation wire 321 decreases, and the tension of the second operation wire 331 increases.

[0105] That is, when the support link 345 is rotated clockwise, the first operation wire 321 increases in tension due to the separation movement of the first take-up pulley 343, and the needle thread adjustment plate 24 moves to the left. Further, accordingly, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are moved to the left by the adjustment linkage portion 27. However, when the support link 345 is rotated clockwise, the second take-up pulley 344 moves closer, so the tension of the second operation wire 331 decreases, and an effect occurs in which the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the right. Therefore, the left-right movement of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 is suppressed or reduced.

[0106] Also, when the support link 345 is rotated counterclockwise, the first operation wire 321 decreases in tension due to the approaching movement of the first take-up pulley 343, and the needle thread adjustment plate 24 moves to the right. Further, accordingly, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are moved to the right by the adjustment linkage portion 27. However, when the support link 345 is rotated counterclockwise, the second take-up pulley 344 moves away, so the tension of the second operation wire 331 increases, and an effect occurs in which the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move to the left. Therefore, the left-right movement of the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 is suppressed or reduced.

[0107] The rotation operation of the support link 345 is performed from the needle thread tension adjustment knob 348 through the lever member 347. The lever member 347 is rotatable by a shaft portion 347a along the left-right direction, and the rotating end portion extends rearward from the shaft portion 347a. An engaging protrusion 347b protruding to the right is provided below the shaft portion 347a and is loosely inserted into an engaging hole 345a provided at the lower end portion of the support link 345. The rotating end portion of the lever member 347 has a spherical bulge at the tip and is inserted inside the needle thread tension adjustment knob 348. The inner bottom portion of the needle thread tension adjustment knob 348 is a spherical concave surface slidable on the spherical rotating end portion of the lever member 347. Therefore, when the needle thread tension adjustment 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 adjustment knob 348 slide against each other, causing the lever member 347 to rotate.

[0108] When the lever member 347 rotates, the engaging projection 347b moves around the shaft portion 347a, and the supporting link 345 can be rotated via the engaging hole 345a. Although the rotation radii of the lever member 347 and the support link 345 are significantly different, the engagement hole 345a is a long hole along the radial direction of the support link 345, so that the difference in rotation radii can be tolerated and the rotational motion can be transmitted from the lever member 347 to the support link 345.

[0109] [Thread reeling mechanism: third input section] 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 section 36, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are moved together in conjunction with each other, so it was not possible to adjust the thread tension of the upper looper thread T3 and the thread tension of the lower looper thread T4 individually. In addition, the sewing type selection unit 28 is capable of changing the mutual distance between the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 by using the spacing member 285, but it is only possible to switch between two mutual distance levels by using the upper and lower positions of the spacing member 285. For this reason, the third input portion 37 is intended to enable adjustment of the mutual distance in the left-right direction between the insertion portion 251 of the upper looper thread adjusting plate 25 and the insertion portion 261 of the lower looper thread adjusting plate 26, while allowing without interfering with the linkage between the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 by the second input portion 33 and the linkage between the needle thread adjusting plate 24 and the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 by the adjustment linkage portion 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 FIGS. 3 and 16 to 18, the third input unit 37 includes a screw shaft 371 along the left - right direction that connects a first member 263 and a second member 264 constituting the lower - loop yarn adjusting plate 26, an input knob 372 as an operation input unit for rotating the screw shaft 371, a movable nut 373 screwed onto the screw shaft 371, and a support bracket 374 that supports the input knob 372.

[0111] The downstream - side guide plate 22 has a right - end portion bent forward and has a side surface portion 225 perpendicular to the left - right direction. The support bracket 374 is attached and supported by screwing near the right - end portion on the front surface of the downstream - side guide plate 22. This support bracket 374 has an attachment surface parallel to the front surface of the downstream - side guide plate 22 and a support surface bent forward from the right - end portion of the attachment surface. The support surface of the support bracket 374 is in close proximity and opposed to the left side of the side surface portion 225 of the downstream - side guide plate 22. Concentric support holes 225a and 374a for supporting the input knob 372 are formed in the side surface portion 225 of the downstream - side guide plate 22 and the support surface of the support bracket 374.

[0112] The input knob 372 is a substantially cylindrical shape with a central axis along the left - right direction, and the right - hand side portion is an input portion for manually gripping and rotating. As shown in FIG. 1, the input portion of the input knob 372 is provided so as to be operable from the outside of the overlock sewing machine 100. Also, the left - end portion of the input knob 372 is inserted into the support hole 225a of the downstream - side guide plate 22 and the support hole 374a of the support bracket 374 and is rotatably supported.

[0113] A gear 372a of a ratchet mechanism is formed on the outer peripheral surface of the left - end portion of the input knob 372 between the side surface portion 225 of the downstream - side guide plate 22 and the support surface of the support bracket 374. And, at the mounting surface of the support bracket 374, the base end portion of a leaf spring 375 extending forward is fixedly supported by screwing. At the front end portion of this leaf spring 375, a wedge-shaped convex portion that meshes with the gear 372a of the input knob 372 is formed. That is, a ratchet mechanism is constituted by the gear 372a and the leaf spring 375. Therefore, the input knob 372 can perform a rotation operation in the pitch unit of the gear 372a, and the leaf spring 375 holds the position (rotation angle) after the operation.

[0114] The input knob 372 penetrates over the entire length in the left - right direction, and the inner diameter of its inner peripheral surface is uniform over the entire length. Further, on the inner peripheral surface of the input knob 372, a key groove 372b is formed from the left end portion to the vicinity of the right end portion of the input knob 372. The left end portion of the key groove 372b is open leftward at the left end portion of the input knob 372.

[0115] The screw shaft 371 is a shaft body whose central axis is along the left - right direction. At its right end portion, it has a round bar - shaped insertion portion 371a to be inserted into the input knob 372, and at its left end portion, it has a screw portion 371b with a male screw formed. Also, a flange portion 371c is provided between the insertion portion 371a and the screw portion 371b, and the insertion portion 371a, the screw portion 371b, and the flange portion 371c are concentric.

[0116] On the outer peripheral surface at the longitudinal middle portion of the insertion portion 371a, a boss - shaped protrusion 371d protruding radially outward of the insertion portion 371a is provided. It is inserted into the key groove 372b inside the input knob 372 described above, and integrally rotates the input knob 372 and the screw shaft 371. Also, the protrusion 371d is axially movable inside the key groove 372b, allowing relative movement along the axial direction (left - right direction) between the input knob 372 and the screw shaft 371. With this structure that allows relative movement along the axial direction between the input knob 372 and the screw shaft 371, the third input unit 37 can allow the interlocking of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 by the second input unit 33 and the interlocking of the needle thread adjusting plate 24, the upper looper thread adjusting plate 25, and the lower looper thread adjusting plate 26 by the adjustment interlocking unit 27.

[0117] With respect to the first member 263 of the lower looper thread adjusting plate 26, the second member 264 is located on the front side and is connected by two step screws 265 in a state where their plate surfaces are overlapped with each other. And both the first member 263 and the second member 264 have their right end portions bent forward and have side faces 263a, 264a perpendicular to the left - right direction. With respect to the side face 263a of the first member 263, the side face 264a of the second member 264 is located on the left side, and they are close to and opposed to each other. Also, a through - hole 263b for inserting and holding the screw portion 371b of the screw shaft 371 is formed in the side face 263a of the first member 263, and a through - hole 264b for inserting and holding the movable nut 373 is formed in the side face 264a of the second member 264, which is substantially concentric with the through - hole 263b.

[0118] The screw shaft 371 has its screw portion 371b inserted into the through - hole 263b from the right side with respect to the side face 263a of the first member 263, and is held by an E - ring 377 so as not to come off to the right in a state where a spring washer 376 is inserted between the right face of the side face 263a and the flange portion 371c. The E - ring 377 is fitted into a circumferential groove formed between the screw portion 371b and the flange portion 371c of the screw shaft 371, and while the screw shaft 371 is rotatably supported with respect to the first member 263, the first member 263 and the screw shaft 371 are integrally connected in the axial direction.

[0119] The movable nut 373 is cylindrical with a screw hole penetrating in the left - right direction, and has a substantially D - shaped cross - section where a part of the outer peripheral surface is flat along the left - right direction. Also, a flange portion 373a is formed at the left end portion of the movable nut 373. On one hand, the through hole 264b in the side surface 264a of the second member 264 is formed in a substantially 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 264a. Furthermore, the movable nut 373 is held by an E-ring 378 on the right side of the side surface 264a so as not to come off to the left with the flange portion 373a in contact with the left surface of the side surface 264a. The E-ring 378 is fitted into a circumferential groove formed on the outer peripheral surface of the movable nut 373, and restricts the left-right movement of the movable nut 373 with respect to the side surface 264a. Note that since both the hole shape of the through hole 264b in the side surface 264a and the cross-sectional shape of the movable nut 373 are substantially D-shaped, the movable nut 373 is held in a state where its rotation is restricted on the side surface 264a of the second member 264. Note that the hole shape of the through hole 264b in the side surface 264a and the cross-sectional shape of the movable nut 373 are not limited to a substantially D shape, and any other shape may be used as long as it can restrict rotation.

[0120] The threaded portion 371b of the screw shaft 371 rotatably supported by the side surface 263a of the first member 263 is screwed into the threaded hole of the movable nut 373 held by the side surface 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. Thereby, the position of the second member 264 can be adjusted in the left-right direction with respect to the first member 263. And since 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 a spring 332, the relative position in the left-right direction of the insertion portion 261 of the lower looper thread adjusting plate 26 with respect 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 the overedge sewing machine] Hereinafter, the operation regarding the feeding of each thread T1 to T4 in the overedge sewing machine 100 will be described.

[0122] When the pitch adjustment knob 131 is rotated in the direction in which the sewing pitch increases, the tension of the first operation wire 321 increases, and the needle thread adjustment plate 24 is moved to the left. Further, by the adjustment interlocking portion 27, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are also moved in the same direction as the needle thread adjustment plate 24. Thereby, the feeding amounts of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 can be increased to correspond to the increase in the sewing pitch.

[0123] When the pitch adjustment knob 131 is rotated in the direction in which the sewing pitch decreases, the tension of the first operation wire 321 decreases, and the needle thread adjustment plate 24 is moved to the right. Further, by the adjustment interlocking portion 27, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are also moved in the same direction as the needle thread adjustment plate 24. Thereby, the feeding amounts of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 are reduced, and it is possible to correspond to the decrease in the sewing pitch.

[0124] When the hemming width adjustment knob 132 is rotated in the direction in which the hemming width increases, the tension of the second operation wire 331 increases, and the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are moved to the left. Thereby, the feeding amounts of the upper looper thread T3 and the lower looper thread T4 can be increased to correspond to the increase in the hemming width.

[0125] When the hemming width adjustment knob 132 is rotated in the direction in which the hemming width decreases, the tension of the second operation wire 331 decreases, and the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 are moved to the right. Thereby, the feeding amounts of the upper looper thread T3 and the lower looper thread T4 are reduced, and it is possible to correspond to the decrease in the hemming width.

[0126] Further, when the thickness of the workpiece on the needle plate 114 increases, the thickness detection lever 351 of the thickness detection unit 35 rotates, the tension of the first operation wire 321 being manually fed increases, the needle thread adjustment plate 24, the upper looper thread adjustment plate 25, and the lower looper thread adjustment plate 26 move leftward, and the feeding amounts of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 increase, enabling correspondence to a thick workpiece.

[0127] Further, when the thickness of the workpiece on the needle plate 114 decreases, the thickness detection lever 351 of the thickness detection unit 35 rotates, the tension of the first operation wire 321 being manually fed decreases, the needle thread adjustment plate 24, the upper looper thread adjustment plate 25, and the lower looper thread adjustment plate 26 move rightward, and the feeding amounts of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 decrease, enabling correspondence to a thin workpiece.

[0128] Further, when the loop thread tension adjustment knob 361 of the loop thread tension setting input unit 36 is operated in the direction in which the thread tensions of the loop threads T3, T4 decrease, the tension of the second operation wire 331 being manually fed increases, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move leftward, and the feeding amounts of the upper looper thread T3 and the lower looper thread T4 increase, enabling reduction of the thread tensions of the upper looper thread T3 and the lower looper thread T4.

[0129] Further, when the loop thread tension adjustment knob 361 is operated in the direction in which the thread tensions of the loop threads T3, T4 increase, the tension of the second operation wire 331 being manually fed decreases, the upper looper thread adjustment plate 25 and the lower looper thread adjustment plate 26 move rightward, and the feeding amounts of the upper looper thread T3 and the lower looper thread T4 decrease, enabling increase of the thread tensions of the upper looper thread T3 and the lower looper thread T4.

[0130] Further, when it is desired to reduce the thread tensions of the needle threads T1, T2 without changing the thread tensions of the loop threads T3, T4, the needle thread tension adjustment knob 348 of the adjustment input unit 34 is operated upward. Thereby, the tension of the first operation wire 321 being manually fed increases, and the tension of the second operation wire 331 decreases. Accordingly, when 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 to the left in conjunction, the reduction in the tension of the second operation wire 331 cancels this out, suppressing fluctuations in the feed amounts of the upper looper thread T3 and the lower looper thread T4, increasing the feed amounts of the needle threads T1, T2, and enabling the reduction of only the thread tensions of the needle threads T1, T2.

[0131] Also, when it is desired to increase the thread tensions of the needle threads T1, T2 without changing the thread tensions of the looper threads T3, T4, the needle thread tension adjustment knob 348 of the adjustment input section 34 is operated downward. As a result, the tension of the manually operated first operation wire 321 decreases, and the tension of the second operation wire 331 increases. Accordingly, when 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, the increase in the tension of the second operation wire 331 cancels this out, suppressing fluctuations in the feed amounts of the upper looper thread T3 and the lower looper thread T4, decreasing the feed amounts of the needle threads T1, T2, and enabling the increase of only the thread tensions of the needle threads T1, T2.

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

[0133] Also, when it is desired to decrease the thread tension of the lower looper thread T4 with respect to the upper looper thread T3, the input knob 372 of the third input section 37 is rotated to move the second member 264 to the left with respect to the first member 263 of the lower looper thread adjustment plate 26. As a result, without moving the upper looper thread adjustment plate 25, only the second member 264 having the insertion portion 261 of the lower looper thread adjustment plate 26 moves to the left, increasing the feed amount of the lower looper thread T4 and decreasing the thread tension.

[0134] Furthermore, when it is desired to adjust the thread tensions of the upper looper thread T3 and the lower looper thread T4 to arbitrary strengths respectively, after adjusting the thread tension of the upper looper thread T3 to the target strength by the looper thread tension setting input unit 36, the thread tension of the lower looper thread T4 may be adjusted to the target strength by the third input unit 37.

[0135] [Technical effects of the edge hemming sewing machine] By including the third input unit 37, the edge hemming sewing machine 100 can adjust the left - right position of the insertion part 261 of the lower looper thread adjusting plate 26 with respect to the insertion part 251 of the upper looper thread adjusting plate 25 without impairing the function of the interlocking of the lower looper thread adjusting plate 26 via the adjustment interlocking part 27 accompanying the position adjustment of the needle thread adjusting plate 24 by the first input unit 32 or the position adjustment of the lower looper thread adjusting plate 26 by the second input unit 33. Therefore, it is possible to adjust the thread tensions of the upper looper thread and the lower looper thread individually without the upper looper thread and the lower looper thread affecting each other.

[0136] Also, the lower looper thread adjusting plate 26 has a first member 263 having a leg part 262 as a connecting part of the spring 332 and a second member 264 having an insertion part 261 as a thread locking part. Since the third input unit 37 is configured to adjust the relative distance along the left - right direction between the first member 263 and the second member 264, it is possible to adjust the position of the insertion part 261 of the lower looper thread adjusting plate 26 without affecting the left - right position of the upper looper thread adjusting plate 25 connected by the spring 332, and it is possible to adjust the thread tensions of the upper looper thread and the lower looper thread individually without the upper looper thread and the lower looper thread affecting each other further.

[0137] Also, the third input unit 37 connects the first member 263 and the second member 264 with a screw shaft 371 along the left - right direction, and an input knob 372 for rotating the screw shaft 371 supports the screw shaft 371 so as to be movable along 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 linkage portion 27 and 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 becomes possible to smoothly interlock with the upper looper thread adjusting plate 25.

[0138] Further, when the edge hemming sewing machine 100 moves the needle thread adjusting plate 24 by pulling the middle portion of the first operation wire 321, the adjustment input portion 34 is provided to suppress or reduce the interlocking of the upper looper thread adjusting plate 25 and the lower looper thread adjusting plate 26 accompanying the movement of the needle thread adjusting plate 24 by the adjustment linkage portion 27 by also pulling the middle portion of the second operation wire 331. Thereby, it is possible to suppress fluctuations in the tensions of the upper looper thread T3 and the lower looper thread T4, and exclusively adjust the thread tensions of only the needle threads T1 and T2, making it possible to perform more diverse sewing with high sewing quality.

[0139] In addition, since the edge hemming sewing machine 100 is configured such that the first input portion 32 includes the pitch adjustment knob 131, it is possible to optimize the feed amounts and thread tensions of the respective threads T1 to T4 in accordance with the increase or decrease of the sewing pitch through the first operation wire 321.

[0140] In addition, since the edge hemming sewing machine 100 is configured such that the second input portion 33 includes the hemming width adjustment knob 132, it is possible to optimize the feed amounts and thread tensions of the respective looper threads T3 and T4 in accordance with the increase or decrease of the hemming width through the second operation wire 331.

[0141] Further, the edge hemming sewing machine 100 has a stitch type selection unit 28 that, when a stitch type is selected, adjusts the respective thread feed amounts of the needle threads T1 and T2, the upper looper thread T3, and the lower looper thread T4 to the thread feed amounts corresponding to the selected stitch type. Therefore, for a plurality of stitch types, it is possible to appropriately feed the respective threads T1 to T4, making it possible to perform more diverse sewing with high sewing quality.

[0142] In addition, since the overedge sewing machine 100 has a thickness detection unit 35 that adjusts the respective thread feed amounts of the needle threads T1, T2, the upper looper thread T3, and the lower looper thread T4 according to the thickness of the workpiece to be sewn, each thread T1 to T4 can be properly fed according to the thickness of the workpiece to be sewn, and sewing according to the thickness of the workpiece to be sewn can be performed with high sewing quality.

[0143] In addition, since the overedge sewing machine 100 has a looper thread tension setting input unit 36 that adjusts the thread tensions of the upper looper thread T3 and the lower looper thread T4, fluctuations in the thread tensions of the left and right needle threads T1, T2 can be suppressed, and only the thread tensions of the upper looper thread T3 and the lower looper thread T4 can be adjusted, enabling more diverse sewing to be performed with high sewing quality.

[0144] [Others] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. For example, in the embodiments, components integrally formed by a single member may be replaced with components divided into a plurality of members and connected or fixed to each other. Also, components configured by connecting a plurality of members may be replaced with components integrally formed by a single member. In addition, the details shown in the embodiments can be appropriately changed without departing from the gist of the invention.

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

[0146] Also, if the input knob 372 of the third input unit 37 is not rendered inoperable (for example, hidden inside the cover of the overedge sewing machine 100), it may be attached in a structure that moves in the left-right direction together with the first member 263 of the lower looper thread adjustment plate 26.

[0147] In the above embodiment, the lower loop thread adjustment plate 26 is exemplified as being composed of two members, a first member 263 and a second member 264. However, the upper loop thread adjustment plate 25 may be composed of 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 position in the left - right direction between the first member and the second member of the upper loop thread adjustment plate 25.

[0148] Also, the arrangement of each of the pulleys 341 to 344 of the adjustment input portion 34 is not limited to the above example, and can be arbitrarily changed as long as the same effect can be obtained. For example, although it was exemplified that the pulling - out direction of the first pulling - out pulley 343 with respect to the first contact pulley 341 and the pulling - out direction of the second pulling - out pulley 344 with respect to the second contact pulley 342 are substantially in the same direction, when these are in opposite directions to each other, it is not necessary to arrange the first pulling - out pulley 343 and the second pulling - out pulley 344 in an arrangement sandwiching the support shaft 346a of the support link 345. In this case, it is preferable to arrange the first pulling - out pulley 343 and the second pulling - out pulley 344 on the same - direction side with respect to the support shaft 346a of the support link 345. Further, instead of making the support link 345 rotatable, the first pulling - out pulley 343 and the second pulling - out pulley 344 may be configured to move linearly into and out of contact with respect to the first contact pulley 341 and the second contact pulley 342.

Explanation of Reference Numerals

[0149] 100 Hem - turning sewing machine 2 Thread - feeding mechanism 21 Up - stream guide plate (up - stream guide portion) 211 - 214 Introduction portions 215 Support column 216 Opening 22 Down - stream guide plate (down - stream guide portion) 221 - 224 Discharge portions 23 Pull - out plate (pull - out portion) 231 - 234 Insertion portions (thread - locking portions) 24 Needle - thread adjustment plate (needle - thread adjustment portion) 241, 242 Insertion portions (thread - locking portions) 25 Upper - loop thread adjustment plate (upper - loop thread adjustment portion) 251 Insertion part (thread fixing part) 252 Leg part (connection part) 253 Arm part 26 Lower looper thread adjustment plate (lower looper thread adjustment part) 261 Insertion part (thread fixing part) 262 Leg part (connection part) 263 First member 263a Side face part 263a Side face part 264 Second member 264a Side face part 265 Step screw 27 Adjustment linkage part 271 Linkage plate 273 Movable pulley 28 Stitch type selection part 32 First input part 321 First operation wire 33 Second input part 331 Second operation wire 34 Adjustment input part 35 Thickness detection part 36 Looper thread tension setting input part 37 Third input part 371 Screw shaft 372 Input knob 373 Movable nut 374 Support bracket 115 - 118 Thread guide groove 131 Pitch adjustment knob (setting input part) 132 Stitch width adjustment knob (setting input part) FA Front side area RA Rear side area M point T1 Left needle thread T2 Right needle thread T3 Upper looper thread T4 Lower looper thread

Claims

1. A needle vertical movement mechanism for performing vertical movement of a sewing needle through which a needle thread is passed, A lower looper mechanism provided with a lower looper for inserting a lower looper thread into a loop of the needle thread, An upper looper mechanism provided with an upper looper for inserting an upper looper thread into a loop of the lower looper thread, A feeding mechanism for feeding a workpiece to be sewn, An overedge sewing machine comprising a thread feeding mechanism for feeding 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 feeding mechanism includes An upstream guide portion having an introduction portion for each thread through which the needle thread, the upper looper thread and the lower looper thread are individually inserted, A downstream guide portion having a lead-out portion for each thread through which the needle thread, the upper looper thread and the lower looper thread are individually inserted, A pulling-out portion that reciprocates along the crossing direction with respect to the needle thread, the upper looper thread and the lower looper thread passing from the respective introduction portions to the lead-out portions between the upstream guide portion and the downstream guide portion, and pulls out the needle thread, the upper looper thread and the lower looper thread from their respective supply sources, A thread locking portion that restrains the needle thread in the crossing direction, and between the upstream guide portion and the downstream guide portion, by moving along the crossing direction, varies the path of the needle thread passing from the introduction portion to the lead-out portion, and adjusts the pulling-out length of the needle thread by the pulling-out portion, A thread locking portion that restrains the upper looper thread in the crossing direction, and between the upstream guide portion and the downstream guide portion, by moving along the crossing direction, varies the path of the upper looper thread passing from the introduction portion to the lead-out portion, and adjusts the pulling-out length of the upper looper thread by the pulling-out portion, It has a thread locking portion for restraining the lower looper thread in the crossing direction, and between the upstream guide portion and the downstream guide portion, by moving along the crossing direction, it varies the path of the lower looper thread passing from the introduction portion to the lead-out portion, and adjusts the pulling-out length of the lower looper thread by the pulling-out portion. A first input portion for moving the needle thread adjusting portion along the crossing direction. A second input portion for moving the upper looper thread adjusting portion and the lower looper thread adjusting portion in conjunction along the crossing direction. An adjustment linkage portion for interlocking the upper looper thread adjusting portion and the lower looper thread adjusting portion when the needle thread adjusting portion moves. A third input portion for inputting adjustment of the relative position along the crossing direction between the thread locking portion of the upper looper thread adjusting portion and the thread locking portion of the lower looper thread adjusting portion while allowing the interlocking by the second input portion and the adjustment linkage portion. The edge hemming sewing machine is characterized by comprising the same.

2. The second input portion has a spring connecting the upper looper thread adjusting portion and the lower looper thread adjusting portion. Either one of the upper looper thread adjusting portion and the lower looper thread adjusting portion has a first member having a connecting portion of the spring and a second member having the thread locking portion. The third input portion adjusts the relative distance along the crossing direction between the first member and the second member. The edge hemming sewing machine according to claim 1 is characterized by the same.

3. The third input portion has a screw shaft along the crossing direction connecting the first member and the second member, and an operation input portion for rotating the screw shaft. The operation input portion supports the screw shaft so as to be movable along the crossing direction. The edge hemming sewing machine according to claim 2 is characterized by the same.

4. The first input portion includes a setting input portion for the sewing pitch. The edge hemming sewing machine according to claim 1 is characterized by the same.

5. The edge hemming sewing machine according to claim 1, wherein the second input unit includes a setting input unit for the hemming width.

6. The edge hemming sewing machine according to claim 1, further comprising a stitch type selection unit that, when a stitch type is selected, adjusts the respective thread feed amounts of the needle thread, the upper looper thread, and the lower looper thread to thread feed amounts corresponding to the selected stitch type.

7. The edge hemming sewing machine according to claim 1, further comprising a thickness detection unit that adjusts the respective thread feed amounts of the needle thread, the upper looper thread, and the lower looper thread according to the thickness of the workpiece to be sewn.

8. The edge hemming sewing machine according to claim 1, further comprising a looper thread tension setting input unit for setting and inputting the thread tensions of the upper looper thread and the lower looper thread.

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