JP2007296377A - Stitch forming device of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stitch forming device of a sewing machine in which a knife severing mechanism part can be compactly included in an existing structure space of the sewing machine and work can be switched easily between a lock stitch after cutting a cloth edge with newstitching and work of performing the lock stitch without cutting the cloth edge. <P>SOLUTION: An upper knife 72 which moves up and down through a motion converting mechanism 71 associated with a rotary shaft S1 which drives a needle 10, and a knife driving part 710 which cuts the cloth edge of a sewn body by a lower knife 73 slidably guiding the upper knife to cooperate with the upper knife, are pivoted to a machine frame so as to displace with drawing an irregular ellipse locus between an operation position on a needle plate 8 in knife operation and a retracted position of the lower part of an arm of the sewing machine knife non-operation by a quadric linkage 730 having different internode lengths, and in the motion converting mechanism, a knife driving part transmits vertical motion to the upper knife at the operation position and is connected with the upper knife through a knife clutch 75 which intercepts the vertical motion to the upper knife at the waiting position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stitch forming device for a sewing machine, and particularly has a function of a main sewing and an edge stitching, and a cloth edge can be cut with a knife in any sewing, and is formed at a time by one sewing machine. The present invention relates to a stitch forming device for a sewing machine.

  Conventionally, there is a main stitch in the most basic stitch formed by a sewing machine as a stitch for stitching a plurality of fabrics and the like. The main stitch is formed by crossing the upper thread and the lower thread by scooping the upper thread passed through the needle with the sword tip of the hook that houses the lower thread when the cloth is penetrated by the vertical movement of the needle. Multiple fabrics can be joined together along the seam.

  On the other hand, there is edge stitching in order to prevent fraying of an edge of a fabric or the like that is easily frayed. Edge stitching is based on the number of threads used to form the stitches and the number of needles that move substantially perpendicular to the fabric surface. Two stitches (ISO4915 Stitch type 503) and three single needles are used. There are thread-edge stitches (ISO4915 Stitch type 504), and two-needle 5-thread stitches (ISO4915 Stitch type 516), which is commonly called interlock that combines chain stitches and edge-lock stitches.

  However, in such edge stitching, for example, the needle thread is scooped from the side with two hook-shaped needles called loopers, and the needle loops the looper thread that moves horizontally to form a stitch. On the other hand, since the looper thread does not cross in the direction perpendicular to the cloth surface, the cloth and the cloth cannot be joined together as in the case of main sewing. That is, a phenomenon called “laughing” occurs in which the two pieces of fabric joined together by edge stitching are exposed when they are opened. For this reason, a stitch (ISO4915 Stitch type 517) for performing a main stitch must be formed together when a plurality of fabrics are edged together.

  It is desirable for such stitches (Stitch type 517) that the main stitching portion and the edge portion are as close as possible, but the main sewing requires a hook portion for storing the lower thread below the needle that moves up and down, On the other hand, edge stitching requires a looper that moves so as to cross the trajectory of the vertical movement of the needle, which is provided separately from the main sewing, and therefore there is a limit in both positions.

  Then, although the sewing machine for both the main stitch and the edge stitch has been proposed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3), these are sewing machines that select and use one of the functions, It was impossible for the sewing machine mechanism to perform the main sewing and the edge stitching in close proximity.

  On the other hand, attempts to perform main stitching and edge stitching at once are also proposed (see, for example, Patent Document 4, Patent Document 5, Patent Document 6, and Patent Document 7). However, in these proposals, edge loop stitching is a looper that crosses the trajectory of the vertical movement of the needle that is provided separately from the main stitch, and that movement applies the looper motion in the conventional edge stitching as described above. Therefore, the main sewing requires a hook portion for storing the lower thread below the needle that moves up and down, and the edge over stitching is a looper that moves so as to cross the locus of the vertical movement of the needle provided separately from the main sewing. Therefore, both positions are naturally limited, and it is difficult for the sewing machine mechanism to perform the main sewing and the edge stitching in close proximity at once.

  Further, a lock stitch attachment (trade name “ruby lock” manufactured by Toyo Seiki Kogyo Co., Ltd.) that performs lock stitching and edge stitching at once is proposed (see Patent Document 8). As shown in FIG. 28, this attachment is used by being fixed to a presser bar 1001, and a crank 1003 pivotally supported on an attachment frame 1002 by a needle bar (not shown) that carries a needle 1011. The drive arm 1003a is driven, and the driven arm 1003b swings the upper looper drive plate 1005 pivotally supported by the attachment frame 1002 via the drive connection link 1004. By swinging the upper looper driving plate 1005, the upper looper 1007 pivotally supported by the attachment frame 1002 through the upper looper driving link 1006 is swung. On the other hand, a pin 1005a protruding from the upper looper drive plate 1005 by the swinging of the upper looper drive plate 1005 slides in a groove 1008a provided in the lower looper drive plate 1008 pivotally supported by the attachment frame 1002. The lower looper drive plate 1008 is swung. The lower looper driving plate 1008 swings the lower looper 1010 pivotally supported by the attachment frame 1002 via the lower looper driving link 1009. In this attachment structure, the upper looper 1007 has to cross the needle 1011 on the upper surface of a cloth (not shown), and therefore, the upper looper 1007 is inclined upward to the left when viewed in the cloth feed traveling direction. Since the needle 1011 must be crossed on the lower surface of the cloth, the needle 1011 is inclined to the left when viewed in the cloth feeding direction, and further, the upper and lower loopers 1007 and 1010 are inclined so as to intersect on the side of the cloth edge of the cloth. is doing.

  In the figure, reference numeral 1014 denotes a needle drop portion of the needle 1011, 1012 denotes a thread tension device, and 1013 denotes a looper balance driven by a lower looper driving plate 1008.

  In the attachment constructed as described above, when the needle bar moves up and down, the needle bar (not shown) pierced by the needle 1011 and the lower thread (not shown) stored in the hook (not shown) The stitches are formed and the needle bar drives the drive arm 1003a of the crank 1003. The driven arm 1003b swings the upper looper drive plate 1005 via the drive connection link 1004, and the upper looper drive plate 1005 swings. Thus, the upper looper 1007 is swung via the upper looper driving link 1006, and a pin 1005 a protruding from the upper looper driving plate 1005 by the swinging of the upper looper driving plate 1005 is a groove provided in the lower looper driving plate 1008. The lower looper driving plate 1008 is slid by sliding on the lower looper driving plate 1008, and the lower looper driving link 10 is moved by the swinging of the lower looper driving plate 1008. Since swinging the lower looper 1010 via 9, overedge sewing by looper thread after having pierced the respective upper looper 1007 and the lower looper 1010 and the lower looper thread (not shown) is formed.

  However, in such an attachment, since the upper and lower loopers 1007 and 1010 are inclined, an advanced manufacturing technique for manufacturing is required, and a technique for maintaining assembly accuracy is required. However, since this type of lockstitch machine is used by ordinary users or at home, it is extremely troublesome to replace the attachment with a presser foot and fix it to the presser foot. In addition, the operation of adjusting the positional relationship between the upper looper 1007 and the lower looper 1010 with respect to the fixed needle is very cumbersome, and further, the edge for sewing the edge of the cloth is cut in advance using a scissors, and then the edge sewing is performed. There is a serious difficulty in performing work.

  Therefore, the inventor of the present application has proposed a one-needle four-thread main-stitched edge stitch structure and a method for forming the same that can function as a main stitch and an edge stitch, and can be formed once by a sewing machine. (See Patent Document 9). For users of the main sewing machine, it has been strongly desired to research and develop a main sewing machine that can realize the above-mentioned proposed single-needle four-thread main sewing edge structure and the forming method thereof.

  In response to such a demand, the present inventor has proposed a looper drive mechanism for a sewing machine (see Patent Document 10).

  This looper drive mechanism of the sewing machine forms a main stitch part composed of a seam parallel to the surface of the body to be sewn and a vertical seam by an upper thread pierced by a needle and a lower thread stored in a hook. At the same time, the looper drive mechanism that forms the edge of the upper looper thread and the lower looper thread pierced by the upper looper and the lower looper respectively has the side surface on the near side of the needle as seen from the sword tip of each looper in the sewing direction. A looper drive unit is provided which is disposed so as to pass in the same direction and drives the upper looper and the lower looper so that the movement loops of the upper looper and the lower looper move in planes substantially parallel to each other. .

  In such a looper driving mechanism, the upper looper and the lower looper pass through the same surface on the front side of the needle, the upper looper crosses the needle above the needle plate, and the lower looper is below the needle plate. The upper looper moves backward along the needle, descends in a circular path, and the upper looper passes through the lowest point and rises before the lower looper reaches the final retreat point. The lower looper trajectory passes through the lower looper trajectory before crossing the upper looper trajectory.

  However, such a looper drive mechanism has a configuration in which the upper looper and the lower looper have a shape of an upper looper and a lower looper because the upper looper's sword tip descends while drawing an arcuate path approaching the yarn outlet of the lower looper's sword that moves backward. Limited, and the thickness of the looper itself could not be increased. In addition, when the upper looper ascends, it is configured to pass immediately before the retreating lower looper sword tip, so the shape of each sword tip of the upper looper and lower looper is inevitably limited, and there is a margin when these loopers cross. Since it disappears, it is easy for jumps to occur.

  In addition, this looper drive mechanism has to incline the movement surface drawn by the upper and lower loopers with respect to the vertical movement direction of the needle, so that the looper drive unit itself is attached to the machine frame so as to incline. The mounting seat must be tilted, which makes processing difficult and makes it difficult to achieve processing accuracy. Therefore, it is difficult to adjust the position when assembling the upper and lower loopers that move on the inclined moving surface.

  In addition, since this looper drive mechanism has a structure in which the looper drive shaft is installed above the lower shaft, the space for incorporation is limited and assembly becomes difficult.

  In addition, because the upper looper that is raised and lowered by the looper drive mechanism at the time of edge stitching, the upper looper up / down holes that open on the bed upper surface must be closed by the lid cover during the main sewing, so the stitch changeover At this time, the cover must be removed and opened, and attached and closed. When the cover is opened, it is necessary to store and manage the cover, which is troublesome and sometimes causes an accident that the cover is lost. Further, in the stitch changeover operation from the main stitch to the edge stitching, there is a troublesome operation of switching to the edge stitching after selecting the stitch.

  In addition, one needle, two thread edge stitching (ISO4915 Stitch type 503), one needle, three thread edge stitching (ISO4915 Stitch type 504), two needles to form the stitches for edge stitching Thread sewing (ISO4915 Stitch type 516) or the like is one in which the edge of a cloth is cut by a knife consisting of an upper knife that moves up and down and a lower knife that cooperates with the upper knife.

  Therefore, as in the case of edge stitching, simple edge stitching can be performed in zigzag stitching by cutting the fabric edge with a knife and performing zigzag stitching.

  For this reason, a sewing machine in which a knife cutting function is added to the main sewing has been proposed (see, for example, Patent Document 11, Patent Document 12, and Patent Document 13).

  However, in general, it is desirable that the main sewing machine and the knife cutting mechanism be as close as possible to each other, in addition to the reason that the main sewing machine must be made small. For this reason, there is a limit to incorporating the knife cutting mechanism into the existing structure space of the main sewing machine, and this is the case for the main sewing machine that performs main sewing and cloth edge cutting at once. Realization and commercialization have been difficult due to the mechanism of the main sewing machine.

  Therefore, the inventor of the present application can incorporate a knife cutting mechanism portion into the existing structure space of the sewing machine, and can perform main sewing without cutting the cloth edge and cutting the cloth edge and performing the edge stitching on the main sewing. There has been proposed a knife driving mechanism for a sewing machine that can be easily switched and executed (see, for example, Patent Document 14 and Patent Document 15).

  The sewing machine's knife drive mechanism is supported by an upper knife that moves up and down via a motion conversion mechanism that is linked to the rotational axis of the sewing machine, a lower knife that cooperates with the upper knife and cuts the fabric edge, and is supported by the machine frame. This movement conversion mechanism is provided to the upper knife via a clutch that pivots the knife drive section to the retracted position when the knife is inactive and shuts off the power to the upper knife. It is connected.

  Such a knife driving mechanism of the sewing machine can be accommodated only by rotating the upper knife as viewed from the operator to the upper left.

  However, such a knife drive mechanism of the sewing machine has a knife drive section having an upper knife installed on the right side of the needle as viewed from the operator, so that the upper knife crosses the front side of the needle with the needle when stored. Will be moved to. That is, since the upper thread is suspended from the balance located above the arm and is inserted into the thread hole of the needle, the upper knife crosses the upper thread when the upper knife is stored, which causes trouble in the sewing. The upper thread must be re-threaded each time it is installed or stored. In order to eliminate such difficulties, it is conceivable to rotate the upper knife to the upper right and store it. However, the width of the lower end of the sewing machine arm becomes larger and the pocket under the arm becomes narrower, which hinders sewing operations. Will come.

  Further, the threading operation of passing the looper thread through the upper looper and the lower looper is a manual operation, which is difficult with a sewing machine in which a looper thread balance is incorporated in the sewing machine bed and the work space is limited. In particular, in the case of a sewing machine that uses a free-arm type cylindrical bed, the work space is further reduced, so that the threading work to the upper and lower loopers should be performed by opening the cover provided on the free arm of the bed. It must be threaded with tweezers in a narrow space between parts, which is a very troublesome operation.

  Therefore, the inventor of the present application has proposed a threading device for a sewing machine capable of automatically passing a thread through the looper with one touch using a pressurized gas in the upper looper and the lower looper (see Patent Document 16). .

  This sewing machine threading device has a looper having a hollow structure from a looper thread inlet to a looper blade tip thread outlet, a thread introduction part into which a thread guided to the looper is inserted, and a hollow having a thread guide outlet in contact with the thread inlet of the looper Thread guide, a moving device that integrally connects the yarn introducing portion to the looper blade tip yarn outlet, and an air pump that feeds the yarn from the yarn introducing portion integrally connected by the moving device to the looper blade tip yarn outlet. Yes.

  Such a threading device for a sewing machine can perform threading to the looper in a sewing machine having a looper with one touch, simplifying the threading operation and preventing malfunction.

  However, such a threading device for a sewing machine cannot be threaded by connecting a looper to a hollow thread guide unless the hand pulley is turned and the threading set button is pressed at a predetermined position. In addition, after the threading is completed, an operation to release the connected thread guide has to be performed. Further, since it was not possible to connect the hollow yarn guide to the looper from the direction other than the movement direction of the looper, it was difficult to apply to a high-speed rotating sewing machine.

  In addition, since the upper looper yarn and the lower looper yarn are supplied directly from the yarn guide to the upper looper and the lower looper, it is not possible to appropriately control the yarn tightening timing and the yarn supply amount. Therefore, it is difficult to balance the thread tension between the upper and lower threads of the main stitching section and the upper and lower looper threads of the edge stitching section, and curling (edges) when loosening of the upper and lower looper threads at the end of sewing is reduced. If the upper looper yarn and the lower looper yarn are loosened, the fabric end is lifted and it becomes difficult to perform a thread tension operation for producing a desired stitching. Furthermore, since the upper looper thread and the lower looper thread may pull the upper thread and the lower thread of the main sewing portion, it is difficult to form a beautiful stitch.

  The present invention has been made in order to solve such a conventional problem, and has the functions of main sewing and edge stitching, and can be formed at one time by one sewing machine. The knife cutting mechanism can be incorporated into the existing structural space, and the work of cutting the cloth edge and performing the edge stitching to the main sewing and the work of performing the main sewing without cutting the cloth edge can be switched and executed. Furthermore, the present invention relates to a stitch forming device for a sewing machine that can be simply threaded.

Japanese Patent Publication No.56-15268 Japanese Patent Publication No. 60-25145 Japanese Examined Patent Publication No. 61-25396 JP-A-55-113490 JP 55-136085 A JP 55-146190 A JP-A-63-122495 Japanese Patent No. 2541601 Japanese Patent No. 2672097 JP 2002-102574 A Japanese Utility Model Publication No. 57-90056 Japanese Utility Model Publication No. 57-90057 Japanese Patent Publication No.58-31950 JP 2002-018170 A JP 2002-126386 A Japanese Patent No. 2865470

  The sewing machine for forming a sewing machine according to the present invention that achieves the above object comprises a needle plate comprising an upper thread pierced by a needle that moves vertically along a locus in a direction perpendicular to the needle plate and a lower thread stored in a hook. When the upper thread that penetrates the sewing body and pierces the needle that reciprocates vertically is raised from the bottom dead center of the needle to the lower side of the needle plate, Straight stitch, zigzag consisting of stitches parallel to the surface of the workpiece and vertical stitches by crossing the upper thread and lower thread by rolling with the sword tip of the rotary hook which houses and rotates the lower thread Forms a main sewing part such as sewing, reciprocates to draw a trajectory above and below the needle plate, draws a trajectory above the needle plate, an upper looper that intersects the needle trajectory, and below the needle plate. The edge loop stitch is formed by the upper and lower looper threads threaded through the lower looper that intersects the looper trajectory. Together, it is for the cloth feed control of the present sewing or needle of the needle drop control in accordance with the stitch selection stitch selection device switches the overedge sewing sewing mode and the fabric workpiece.

  This sewing machine seam forming apparatus is covered by an upper knife moving up and down via a motion conversion mechanism linked to a rotating shaft that drives a needle and a lower knife cooperating with the upper knife so as to slidably guide the upper knife. An irregularity between the operating position on the needle plate when the knife is activated and the lower position of the arm of the sewing machine when the knife is inactive is achieved by using a four-joint rotary link with a different internode length for the knife drive section that cuts the fabric edge of the sewing body. It is pivotally attached to the machine frame so as to draw an elliptical trajectory, and the motion conversion mechanism transmits the vertical movement to the upper knife at the operating position of the knife drive unit, and blocks the vertical movement to the upper knife at the retracted position. Is connected to the upper knife through a knife clutch.

  The sewing machine for forming a stitch of the sewing machine of the present invention is placed on the throat plate by an upper thread pierced by a needle that moves up and down in a direction perpendicular to the throat plate and a lower thread stored in the hook. When the upper thread that penetrates the sewing body and pierces the needle that reciprocates in the vertical direction is lifted from the bottom dead center of the needle, For example, straight stitching, zigzag stitching, etc. consisting of stitches parallel to the surface of the body to be sewn and vertical stitches by crossing the upper thread and lower thread with a sword tip of a rotary hook that stores and rotates. This is to perform the main sewing.

  This sewing machine stitch forming device is covered by an upper knife that moves up and down via a motion conversion mechanism that is linked to a rotation shaft that drives a needle, and a lower knife that cooperates with the upper knife to slidably guide the upper knife. An irregularity between the operating position on the needle plate when the knife is activated and the lower position of the arm of the sewing machine when the knife is inactive is achieved by using a four-joint rotary link with a different internode length for the knife drive section that cuts the fabric edge of the sewing body. It is pivotally attached to the machine frame so as to draw an elliptical trajectory, and the motion conversion mechanism transmits the vertical movement to the upper knife at the operating position of the knife drive unit, and blocks the vertical movement to the upper knife at the retracted position. Is connected to the upper knife through a knife clutch.

  According to the stitch forming device of the sewing machine of the present invention, the knife cutting mechanism can be compactly incorporated into the existing structure space of the sewing machine, and the work of cutting the cloth edge and performing the edge stitching to the main stitch The operation of performing the main sewing without cutting the cloth edge can be easily switched and executed.

  Further, according to the stitch forming apparatus for a sewing machine of the present invention, the knife cutting mechanism can be compactly incorporated in the existing structure space of the sewing machine, and the edge of the main sewing is performed by cutting the cloth edge. The work and the work of performing the main sewing without cutting the cloth edge can be easily switched and executed.

  As described above, according to the stitch forming device for a sewing machine of the present invention, the sewing machine has both functions of a main sewing and an edge stitching, and can be formed at one time by one sewing machine. The knife cutting mechanism portion can be incorporated in the structure space, and the work of cutting the cloth edge and performing the edge stitching to the main sewing and the work of performing the main sewing without cutting the cloth edge can be switched and executed.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment in which a stitch forming device for a sewing machine according to the present invention is applied to an overlock sewing machine will be described below with reference to the drawings.

  As shown in FIG. 1, the main stitch edge sewing machine includes a main stitch forming mechanism 100 that forms a main stitch portion composed of stitches parallel to and perpendicular to the surface of the body to be sewn, and the surface of the body to be sewn. And a looper driving mechanism 50 for forming an edge portion.

  The main stitch forming mechanism 100 has a known (well-known) structure (Japanese Patent Laid-Open Nos. 49-117148, 52-154448, 53-108547, 54-60052). No. 54, No. 54-110049, No. 55-35676, No. 55-113490, No. 55-146190, No. 56-3091, etc.) Detailed description thereof will be omitted. However, in brief, as shown in FIG. 2, the needle 10 is fixed to the needle bar 11 (FIG. 3) and moves up and down in a direction perpendicular to the needle plate 8, and the needle 10 moves up and down. And a hook 20 which performs a horizontal rotational movement that draws a locus L20 in the same cycle, and the upper thread 1 pierced by the needle 10 and the lower thread 2 accommodated in the hook 20 are placed on the needle plate 8. When the upper thread 1 pierced through the needle 10 that reciprocates in the vertical direction through the sewing body for every feed of the sewing body is lifted from the bottom dead center of the needle 10, it is below the needle plate 8. A book composed of stitches parallel to the surface of the body to be sewn and perpendicular stitches by crossing the upper thread 1 and the lower thread 2 with the sword tip 21 of the hook 20 which houses the lower thread 2 and rotates horizontally. The sewing part 6 is formed.

  As shown in FIGS. 1 and 3, the needle bar 11 on which the needle 10 is fixed to the distal end portion is supported by a needle frame pivotally supported by the machine frame FR so as to be slidable in the vertical direction. The needle bar drive unit MT1 having a needle bar crank as a conversion mechanism moves up and down. Further, the hook (sword tip) 20 may be not only fully rotated but also half-turned. In short, if the locus L20 and the locus L10 of the needle 10 cross each other and the upper thread 1 moves by the sword tip 21, It is good (see FIG. 2).

  In addition, in the main stitch edge sewing machine, the sewing operator performs linear stitching, zigzag stitching, etc. by rotating the stitch selection knob NB and switching the pattern stitch selection dial DL to various sewing modes according to the respective rotational positions. be able to. The main sewing forming mechanism 100 corresponding to the sewing mode is also a known (well-known) structure (Japanese Patent Laid-Open Nos. 48-50853, 49-32754, 50-73754, JP 54-4646, JP 54-6663, JP 54-120057, JP 55-16676, Japanese Utility Model 55-216, Japanese Utility Model 55-4787. For example, when the needle 10 is moved up and down, the needle 10 is moved in a direction perpendicular to the cloth feeding direction for each needle and cooperates with the cloth feeding. A needle drop controller 110 (see FIG. 3) for generating zigzag stitching and pattern stitching is provided. The needle entry control unit 110 includes a pattern stitch generation device 120, a stitch selection device 130, and a needle vibration device 140. The pattern stitch generation device 120 and the stitch selection device 130 are unitized. The eye generating device 120 is incorporated in the upper portion of the stitch selecting device 130, and controls the needle drop of the needle 10 in conjunction with the switching control of the lock stitch / edge-shift switching control unit 510 described later. As a result, when the lock stitch / edge switch control unit 510 is controlled to switch to the lock stitch, the needle drop control unit 110 is interlocked with the switch control to the lock stitch by the lock stitch / edge switch control unit 510, 10 is automatically moved to the main stitch needle drop position, and when the main stitch / edge shift switching control unit 510 is controlled to switch to the edge stitch, the needle drop control unit 110 performs the main stitch control unit 110. The needle drop control can be performed so that the position of the needle 10 is automatically moved to the edge over stitching needle drop position in conjunction with the control for switching to the edge over stitch by the sewing / edge over change control unit 510.

  The stitch selection device 130 is rotated by an operation of the stitch selection knob NB (see FIG. 1), and a stitch selection shaft 131 for setting a pattern stitch and various stitches are displayed and a stitch selection shaft 111 is displayed by a gear mechanism. The pattern stitch selection dial DL is linked to the sewing machine. When the sewing operator operates the stitch selection knob NB to selectively switch the stitches, the desired cam is selected from the various cams of the pattern stitch generation device 120. The needle swing amount, the needle swing position, and the needle feed amount are determined. The feed amount of a feed dog FB, which will be described later, is adjusted by a feed adjustment knob 131a (see FIG. 3).

  Since the needle drop control unit 110 is also a known (well-known) structure, detailed description thereof is omitted, but the main stitch forming mechanism 100 is driven and controlled by the pattern stitch generation device 120 and the stitch selection device 130. is doing.

  A lock stitch forming operation by the lock stitch forming mechanism 100 configured as described above will be described with reference to FIGS.

  The needle 10 moves up and down from a rotary shaft, that is, an upper shaft S1, which is pivotally supported by the machine frame FR of the main sewing edge stitching machine, via a needle bar drive unit MT1. Further, the upper shaft S1 drives the upper thread balance 16 for pulling and feeding the upper thread 1 up and down by a motion conversion mechanism 71 (see FIG. 12) described later. The upper shaft S1 is rotationally driven by the hand pulley HP from the motor M via the timing belt TB. In addition, a needle frame (not shown) that supports the needle bar 11 to which the needle 10 is fixed is slidable in the vertical direction, by a needle vibration device 140 that is driven and controlled by the pattern stitch generation device 120. Shift left and right position. The needle plate 8 is formed in a horizontally long shape so that the needle drop hole PS can cope with the change of the left and right positions of the needle 10 (see FIG. 20).

  The shuttle 20 is rotated from a rotary shaft that is pivotally supported on the machine frame FR of the main stitching sewing machine, that is, the lower shaft S2, via a shuttle drive screw gear MT2 that is a motion conversion mechanism. The hook drive screw gear MT2 transmits the rotational motion from the lower shaft S2 to the hook 20 after turning 90 degrees in the feed direction, the driven gear 202 is fixed to the hook 20, and the driving gear 201 is the lower shaft. It is fitted and fixed in S2. The lower shaft S2 is rotated by the timing belt TB in synchronism with the upper shaft S1 and at a double speed (1: 2). The hook 20 rotates twice with respect to the vertical movement of one needle and the timing is adjusted so that when the needle 10 rises from the lowest point, the sword tip 21 of the hook 20 hits the loop of the upper thread 10.

  Further, the feed amount of the feed dog FB of the cloth feed device for cloth feed is also drive-controlled by the pattern stitch generator 120. The cloth feed movement of the feed dog FB is driven from the lower shaft S2 by a feed dog driving section 121 having a triangular cam, and the feed dog driving section 121 raises the feed dog FB to push up the sewing body upward, In this state, the feed dog FB is moved forward to move the sewing body forward, and further, the feed dog FB is lowered to leave the sewing body on the needle plate 8 and the feed dog FB is moved back to the original position. This is one step of cloth feeding. As a result, it is possible to perform the cloth feed control of the sewing object according to the stitch selected by the stitch selection device 130.

  Further, as shown in FIGS. 1 and 2, the main stitch edge sewing machine performs a reciprocating motion that draws a substantially arcuate locus L30 above and below the needle plate 8, and the locus of the needle 10 above the needle plate 8. The upper looper 30 intersecting with L10 and a substantially arcuate locus L40 are drawn below the needle plate 8, and passed through the lower looper 40 intersecting with the locus L10 of the needle 10 and the locus L30 of the upper looper 30, respectively. Further, a looper driving mechanism 50 for forming the edge overhanging portion 7 by the upper looper yarn 3 and the lower looper yarn 4 is provided.

  In this looper driving mechanism 50, an upper looper 30 and a lower looper 40 are provided below the needle plate 8, respectively, and pass through the front side surface of the needle 10 when the sword tips 31 and 41 are viewed in the sewing direction. The upper looper 30 and the lower looper 40 are driven so that their loci L30 and L40 move in planes substantially parallel to each other. The upper looper 30 descends from the top dead center through the upper looper thread 3 that has pierced the upper looper 30 that reciprocates in a circular path L30 that crosses the needle plate 8 and passes through the needle plate 8. The needle 10 descends from the top dead center when scrambling, and is pierced by the lower looper 40 that reciprocates below the needle plate 8 while drawing the locus L40 of the needle 10 and the locus L30 of the upper looper 30. Lower looper thread 4 When the lower looper 40 moves from one end of the locus L40 to the other end, the lower needle 40 is scooped by the lowering needle 10 below the needle plate 8, and when the lower looper 40 moves to the other end, the lower looper thread 4 is lifted from the bottom dead center. The upper looper thread 3 crosses the upper looper thread 3 and the lower looper thread 4 at the edge 5c of the sewing object 5, and the upper looper thread 3 passes through the upper surface 5a of the sewing object 5 and the main sewing part 6. A looper driving portion 60 (FIG. 4) is provided so as to form an edge stitching portion 7 which is crossed and the lower looper thread 4 crosses the main sewing portion 6 through the lower surface 5b of the body 5 to be sewn.

  The looper drive unit 60 is provided below the needle plate 8, and as shown in FIG. 4, the rotational motion from the lower shaft S2 is transmitted via a looper clutch 500 (FIGS. 8, 9, and 10) described later. A crank 61a that is attached to one end of a looper drive shaft 61 that is driven when the looper clutch 500 is engaged and that rotates, an L-shaped looper drive link 62 that is connected to the crank 61a, and a looper base at an intermediate portion. An upper looper mounting arm 63 that is pivotally supported by 67 and is connected to the long link end 62a of the L-shaped looper drive link 62, carries the upper looper 30, and swings in accordance with the rotational movement of the crank 62; A lower looper drive link 64 that is connected to the short link end 62b of the drive link 62 and that moves in an elliptical motion with the rotational movement of the crank 61a, and is pivotally supported by the looper base 67 at an intermediate portion. The lower looper mounting arm 65 is connected to the upper drive link 64 and carries the lower looper 40, and these cranks 61a and the like are incorporated in a looper base 67 attached to the machine frame FR by a looper base mounting plate 620. It is.

  Specifically, the looper drive shaft 61 is rotatably attached to the looper base 67, and the crank 61a is rotatably connected to the long link and short link coupling portion 62c of the L-shaped looper drive link 62. . The upper looper mounting arm 63, one end of which is connected to the long link end 62a of the L-shaped looper drive link 62, is pivotally connected to the looper base 67 at the middle, and the upper looper mounting plate 68 is connected to the other end. The upper looper 30 is fixed. An upper looper thread pipe 301 for inserting the upper looper thread 3 is attached to the upper looper 30. The lower looper drive link 64 having one end connected to the short link end 62 b of the L-shaped looper drive link 62 is pivotally attached to one end of the lower looper drive arm 66. The end is fixed to a lower looper mounting arm 65 whose one end is pivotally attached to the looper base 67 by a lower looper mounting arm shaft 69. A lower looper 40 is fixed to the other end of the lower looper mounting arm 65. A lower looper yarn pipe 401 for inserting the lower looper yarn 4 is attached to the lower looper 40.

  The edge over stitching operation by the looper driving unit 60 will be described with reference to FIGS. 3, 4, 5, and 6.

  When the lower shaft S2 rotates, the looper drive shaft 61 rotates through the looper clutch 500, and the L-type looper drive link 62 connected to the crank 61a of the looper drive shaft 61 converts this rotational motion into another motion. To do. That is, the short link end 62 b of the L-type looper drive link 62 is a four-bar rotation chain formed by a crank 61 a attached to the looper drive shaft 61, an upper looper attachment arm 63, and a long link of the L-type looper drive link 62. Therefore, the lower looper drive arm 66 connected via the lower looper drive link 64 causes the lower looper mounting arm 65 to rotate the looper drive shaft 61. Therefore, the lower looper 40 swings in a circular arc shape from the right side to the left side of the needle 10 when the sewing machine is viewed from the front under the needle plate 8. (FIG. 2 (a)). Further, the long link end 62a of the L-type looper drive link 62 is converted into a vertical motion, and the upper looper mounting arm 63 swings around the shaft fulcrum with respect to the looper base 67 of the upper looper mounting arm 63. The upper looper 30 carried by the upper looper mounting arm 63 is from the right side of the needle 10 when the sewing machine is viewed from the front and from below the sword tip 41 of the lower looper 40 to the left side of the needle 10 and above the needle plate 8 when the sewing machine is viewed from the front. (Fig. 2 (a)).

  The looper clutch 500 for transmitting / cutting off the power from the lower shaft S2 to the looper driving unit 60 is configured to transmit the power from the lower shaft S2 to the looper driving shaft 61 when the edge overhanging portion 7 is formed, so that the main sewing unit 6 and the edge The overlock portion 7 is formed, and when the main sewing portion 6 is formed, the upper looper 30 is retracted at the bottom dead center, and the power is cut off from the lower shaft S2 to the looper drive shaft 61 to form the main sewing portion 6 (FIG. 2 (b )), And a looper drive screw gear MT3 which is a motion conversion mechanism (FIGS. 8 and 9). As shown in FIGS. 8, 9, and 10, the looper drive screw gear MT3 transmits the rotational motion from the lower shaft S2 to the looper drive unit 60 after changing the direction of rotation by 90 degrees in the feed direction. The gear 509 is fixed to the other end of the looper drive shaft 61 that is rotatably fixed to the looper base 67, and the driving gear 505 is slidably fitted to the lower shaft S2.

  Further, the looper clutch 500 is fixed to the end surface of the lower shaft S2 and a looper driving screw gear stopper 503 that is fixed to the looper base 67 with screws and fitted into a recess 505b formed at one end of the driving gear 505. A clutch receiver 506 having a clutch engaging recess 506a into which a clutch pawl 505c formed at the other end of the driving gear 505 is fitted, a driving gear 201 of the shuttle driving screw gear MT2, and a looper driving screw gear MT3. A clutch spring 508 which is loosely fitted to the lower shaft S2 so as to be positioned between the driving side gear 505 and repels in a direction in which the clutch pawl 505c of the driving side gear 505 can be engaged with the clutch engaging recess 506a of the clutch receiver 506; The movement formed in the driving side gear 505 of the looper driving screw gear MT3 incorporated in the lock stitch / edge overshift control unit 510 described later. Looper stop timing arm tip 501a fitted to 505a has a looper stop control plate 501 which is formed at one end.

  The main sewing / edge overhang switching control unit 510 in which the looper stop control plate 501 is incorporated includes a clutch switching plate 511 which is overlapped with the looper stop control plate 501 and fixed to be slidable with respect to each other. Specifically, the looper stop control plate 501 is slidable by a predetermined length in the axial direction of the lower shaft S2 on the convex portions 512a and 512b protruding from the lower surface of the hook mounting base 512 fixed to the machine frame FR. The clutch switching plate 511 is fixed to the stop control plate 501 so as to be slidable by a predetermined length in the axial direction of the lower shaft S2. In addition, a looper stop control tension spring 514 is stretched between a first spring hook 511a provided on the clutch switching plate 511 and a spring hook 501b provided on the looper stop control plate 501. Further, a clutch switching tension spring 513 is stretched between a second spring hook 511b provided on the clutch switching plate 511 and a spring hook 512c provided on the left end of the hook mounting base 512 in FIG. Yes. Accordingly, the clutch switching plate 511 and the looper stop control plate 501 are always repelled in the left direction in FIG.

  In order to control such a lock stitch / edge shift switching control unit 510 between lock stitching and edge stitching in conjunction with stitch selection of the stitch selection device 130, Clutch switching plate 511 is connected to stitch selection device 130.

  The stitch selection device 130 has a stitch switching arm 133 whose one end is engaged with an edge cam 132 fixed to the stitch selection shaft 131 and rotates around the stitch switching arm shaft 134 based on the cam shape. One end of a stitch switching rod 135 is connected to the other end of the stitch switching arm 133. The other end of the stitch switching rod 135 is provided with an adjustment slot 135a, and a connecting piece 514 is loosely fitted in a connecting hole of a connecting portion 511c formed at one end of the clutch switching plate 511. A stitch changeover rod 135 is fixed to a screw 514 with a screw 515 and a washer 516 so that the position of the stitch changeover rod 135 can be adjusted via an adjustment slot 135a.

  In the looper clutch 500 and the main stitch / edge-shift switching control unit 510 configured as described above, when the edge-over stitching is performed, the stitch-switching arm 133 is shown in FIG. Since the stitch switching rod 135 connected to the other end of the stitch switching arm 133 moves in the left direction because it rotates in the clockwise direction (when the sewing machine is viewed from the front), the looper stop control plate together with the clutch switching plate 511 is moved. 501 also moves to the left by the elastic force of the clutch switching tension spring 513 and the looper stop control tension spring 514. When the looper stop control plate 501 moves to the left, the looper stop timing arm tip 501a of the looper stop control plate 501 fitted in the moving groove 505a of the drive side gear 505 of the looper drive screw gear MT3 moves the drive side gear 505. The clutch pawl 505c of the driving gear 505 is engaged with the clutch engaging recess 506a of the clutch receiver 506 fixed to the lower shaft S2 by moving leftward (see FIGS. 9A and 10A). . As a result, the rotational motion of the lower shaft S2 is transmitted to the driven gear 509 (see FIG. 4) via the driving gear 505, so that the upper looper 30 and the lower looper 40 of the looper driving unit 60 are driven.

  Further, when performing the main stitching, the stitch switching arm 133 is rotated counterclockwise in FIG. 8 (when the sewing machine is viewed from the front) by the edge cam 132 of the stitch selecting device 130. Since the stitch switching rod 135 connected to the other end of the arm 133 moves in the right direction, the looper stop control plate 501 as well as the clutch switching plate 511 and the elastic force of the clutch switching tension spring 513 and the looper stop control tension spring 514 are reflected. Move to the right against the force. When the looper stop control plate 501 moves to the right, the looper stop timing arm tip 501a of the looper stop control plate 501 fitted in the movement groove 505a of the drive side gear 505 of the looper drive screw gear MT3 moves the drive side gear 505. Moving in the right direction, the recess 505b of the driving gear 505 can be fitted into the looper drive screw gear stopper 503 against the elastic force of the compression spring 508, and the clutch receiver fixed to the lower shaft S2. The clutch engaging recess 506a of 506 is disengaged from the clutch pawl 505c of the driving side gear 505 (FIG. 9 (b), FIG. 10 (b)). As a result, the rotational movement of the lower shaft S2 is not transmitted to the driving side gear 505, so that the driven side gear 509 does not rotate, and the upper looper 30 and the lower looper 40 of the looper driving unit 60 are stopped.

  The lock stitch sewing machine provided with such a looper drive mechanism 50 further includes a motion conversion mechanism 71 (FIGS. 11 and 12) linked to the rotation axis of the lock stitch sewing machine, that is, the upper shaft S1. A knife driving mechanism 70 that cuts the cloth edge 5c of the cloth 5 (FIG. 2) is provided by an upper knife 72 that moves up and down through the lower knife 73 that cooperates with the upper knife 72.

  The knife drive mechanism 70 is provided with a knife drive unit 710 that is pivotally supported by the machine frame FR and guides the upper knife 72 slidably.

  The motion conversion mechanism 71 transmits power to the upper knife 72 when the knife driving unit 710 is operated, and a female clutch that pivots the knife driving unit 710 to a retracted position when the knife is not operated to cut off power to the upper knife 72. It is connected to the upper knife 72 through 75.

  As shown in FIGS. 1, 11, 12, and 13, the motion conversion mechanism 71 is a first composed of four links 76, 77 (78), 79, and 80 that connect the upper shaft S <b> 1 as a rotation shaft and the machine frame FR. The four-link rotation chain LK1 and one link 79 of the first four-link rotation chain LK1 and the node N4 of the machine frame FR are used, and the drive portion 751 of the female clutch 75 is used as another link 82. , 81, 82, 83, and a second four-joint rotation chain LK 2. In the first four-joint rotation chain LK 1, a link 78 is fixed to the link 77, and the link 78 is connected to the link 80. The link 76 is a fixed link.

  In the embodiment shown in FIG. 12, the motion conversion mechanism 71 takes out motion from a mechanism that drives the balance 16 up and down from the upper shaft S <b> 1 as a rotation shaft, converts the motion, and moves the upper knife 72 up and down. However, the motion conversion mechanism 71 may take out motion from a mechanism that drives the needle 10 up and down from the upper shaft S1 as a rotation axis and convert the motion to move the upper knife 72 up and down. The balance 16 is driven up and down by the four links 76, 77 (78), 79, 80 from the upper shaft S1.

  As shown in FIG. 11, the female clutch 75 includes a pin 84 formed on the other link 82 as the driving unit 751 and a long groove 702 formed on the upper knife 72 as the driven unit 701 and into which the pin 84 is fitted. . The pin 84 is screwed into a mounting hole (not shown) at the bent lower end of another link 82 as the drive unit 751 so that the vertical position can be adjusted by a nut 753.

  As shown in FIG. 14, the knife drive unit 710 is provided with a long groove 702 to be fitted to the pin 84 of the drive unit 751 and an upper knife drive piece 711 to which the upper knife 72 is fixed, and the upper knife drive piece 711. A knife sliding body 712 provided, a lower knife mounting piece 713 provided in parallel with the knife sliding body 712 and to which the lower knife 73 is fixed, and these three parts from the top are an upper knife driving piece 711, a knife sliding body 712, and a lower A knife slide shaft 714 is slidably inserted in the order of the knife attachment piece 713, and an upper knife 72 and a lower knife 73 are disposed so as to cut the cloth.

  The female sliding body 712 is formed with a guide groove 712a in which a convex portion 713a formed on the lower female mounting piece 713 is slidably fitted in the axial direction of the female sliding shaft 714. A female unit base 715 is fixed for movably fixing to the machine frame FR. The knife unit base 715 has an irregular elliptical trajectory between the operating position on the needle plate 8 when the knife is operated and the retracted position below the sewing machine arm when the knife is not operated by the four-joint rotation link 730 having different internode lengths. It is pivotally attached to the machine frame FR to draw and change.

  The four-joint rotation link 730 includes an upper swing arm 731 whose one end is pivotally attached to the upper end of the female unit base 715 and a lower swing arm 732 whose one end is pivotally attached to the lower end of the female unit base 715. The other end of the arm 731 is pivotally mounted between the upper part of the thread guide plate 733 and the upper part of the female unit mounting plate 734, and the other end of the lower swing arm 732 is the lower part of the thread guide plate 733 and the lower part of the female unit mounting plate 734. Axis is attached between. A knife retracting tension spring 736 is stretched between a spring hook 731 a provided on the other end side of the upper swing arm 731 and a spring hook 735 provided on the lower side of the female unit mounting plate 734. The female unit mounting plate 734 is fixed to the machine frame FR. Since the four-joint rotation link 730 is configured in this way, the female unit base 715 can be displaced by drawing an irregular elliptical locus.

  The knife unit base 715 is bent in an L shape so as to cover two predetermined adjacent surfaces of the knife sliding body 712 and the lower knife mounting piece 713. The female sliding body 712 is fixed to the female sliding shaft 714 with a screwing member such as a screw. Further, the knife unit base 715 has an irregular elliptical trajectory between the operating position on the needle plate 8 when the knife is operated and the retracted position below the sewing machine arm when the knife is not operated. A knob 715f is formed for drawing and shifting.

  The lower knife mounting piece 713 has a groove 713b and is engaged with a positioning lever 718 loosely fitted in a slit 715c formed in a bent portion of a knife unit base 715 fixed to the knife sliding body 712. ing. Specifically, the positioning lever 718 is formed with a half-pressing convex portion 718 a as a rotation shaft serving as a fulcrum, and is pivotally supported by a pivoting hole 715 d drilled in the female unit base 715. Further, at one end of the positioning lever 718, a convex portion 718b serving as a load point is formed and engaged with the groove portion 713b of the lower knife mounting piece 713. Accordingly, since the positioning lever 718 is gripped between the knife unit base 715 and the lower knife mounting piece 713, the operation portion 718 c formed at the other end that is the power point of the positioning lever 718 is operated upward. When the rotary knife is rotated, the lower knife mounting piece 713 is lowered while sliding the knife sliding shaft 714. When the operating portion 718c is operated downward to rotate, the lower knife mounting piece 713 causes the knife sliding shaft 714 to move. It will rise while sliding. A concave portion 718d for stopper is formed on the back surface of the convex portion 718b of the positioning lever 718, and protrudes from the female unit base 715 when the positioning lever 718 is operated upward so that the lower knife 73 is lowered to a predetermined position. The stopper convex portion 715e is fitted.

  The lower knife 73 fixed to the lower end portion 713c of the lower knife mounting piece 713 positions the knife driving unit 710 in the positioning recess 8a of the needle plate 8 with respect to the needle drop position PS of the needle 10 when the knife is operated. A positioning locking portion 87 is provided (see FIG. 21).

  On the other hand, the upper knife driving piece 711 has a groove portion 711a, and an upper knife spring plate 719 is fitted into the groove portion 711a and fixed by a screwing member 720 such as a screw. The upper knife spring plate 719 is formed in such a length as to extend from the upper knife drive piece 711 and is slidably fitted in the guide groove 712 a of the knife sliding body 712. An upper knife 72 is fixed to a portion 719 a extending from the upper knife driving piece 711 of the upper knife spring plate 719 by a screwing member 721 such as a screw. The extension portion 719 a of the upper knife spring plate 719 is bent so that the upper knife 72 can be pressed against the lower knife 73 by positively applying the elastic force of the upper knife spring plate 719.

  According to the knife drive mechanism 70 configured as described above, the knife drive unit 710 which is a knife cutting mechanism portion can be compactly assembled in the existing structure space of the sewing machine, and the cloth edge is cut for the main sewing. The operation of performing edge stitching and the operation of performing main sewing without cutting the fabric edge can be easily switched and executed.

  Further, the main stitch edge sewing machine is interlocked with the main stitch / edge change switching control section 500 to switch to the main stitch, and the upper looper thread 3 and the lower looper thread 4 are threaded to the upper looper 30 and the lower looper 40, respectively. A looper threading device 300 for threading is provided in the table of the sewing machine.

  As shown in FIGS. 15 and 16, the looper threading device 300 includes an upper looper thread conduit 305 and a lower looper which are hollow thread guides for sending air supplied from an air pump 304 to the upper looper 30 and the lower looper 40. The yarn conduit 306, the yarn introduction member 307 connected to the upper looper yarn conduit 305 and the lower looper yarn conduit 306, and the air from the air pump 304 are supplied to either the upper looper yarn conduit 305 or the lower looper yarn conduit 306. And a connection switching member 308 that performs switching in such a manner.

  The upper looper 30 and the lower looper 40 have a hollow structure from the looper blade tip thread outlets 30b and 40b to be the blade tip to the looper thread inlet ports 30a and 40a. The upper looper 30 and the lower looper 40 are composed of looper thread pipes 301 and 401 which are tubular members from the looper blade tip thread outlets 30b and 40b to the looper thread inlets 30a and 40a, and the looper thread inlets 30a and 30a are pressurized air. The upper looper yarn conduit 305 and the lower looper yarn conduit 306 are connected to each other. The receiving portions of the looper yarn inlets 30a, 30a are formed in an expanded shape suitable for introduction of the looper yarn, that is, a trumpet shape. Note that the upper looper 30 and the lower looper 40 can themselves be formed of hollow members.

  In addition, the looper yarn inlets 30a and 40a of the upper looper 30, the lower looper 40, the upper looper yarn conduit 305, and the yarn guide outlets 305b and 306b of the lower looper yarn conduit 306 intersect with the moving surface drawn by the upper looper 30 and the lower looper 40. Arranged in a direction. This facilitates processing, assembly and adjustment to match the looper yarn inlets 30a and 40a of the upper looper 30, the lower looper 40 and the yarn guide outlets 305b and 306b of the upper looper yarn conduit 305 and the lower looper yarn conduit 306. Because.

  The air pump 304 includes a cylinder 304a, a piston 304b that slides in the cylinder 304a, and a lever 304c for sliding the piston 304b. The lever 304c is attached in a direction to push down the piston 304b by a spring 304d fixed to the sewing machine body. It is energized. An air supply pipe 304e for sending air is connected to the upper end of the cylinder 304a.

  By depressing the lever 304c in the air pump 304 having such a configuration, the piston 304b is pushed up against the urging force of the spring 304d and sends pressurized air to the air supply pipe 304e. The air supply pipe 304e is connected to the connection switching member 308.

  As shown in FIGS. 17, 18, and 19, the connection switching member 308 includes two air supply ports 381 and 382 that supply air to the yarn introduction member 307, these air supply ports 381 and 382, and an air supply pipe 304e. Is a member formed with a conduit 383 that communicates with each other via a nipple 387, and is combined with the yarn introduction member 307 so that the surface on which the air supply ports 381 and 382 are formed contacts the yarn introduction member 307. A sealing member such as an O-ring for keeping airtightness is fitted into the air supply ports 381 and 382.

  Further, the connection switching member 308 has a protrusion 384 formed on the surface where the air supply ports 381 and 382 are formed, and the protrusion 384 is a corrugated notch 371a formed on the surface of the yarn introduction member 307 opposite to this surface. Engage with. Further, the connection switching member 308 is integrally formed with a slide portion 385 and a knob portion 386 that engage with a slide groove 371b of the yarn introduction member 307, which will be described later, and the connection switching member 308 is operated by operating the knob portion 386. The thread introduction member 307 can be slid along the slide groove 371b. At this time, the connection switching member 308 is positioned at one of the first and second positions with respect to the yarn introduction member 307 by the engagement of the corrugated notch 371 a of the yarn introduction member 307 and the protrusion 384.

  The yarn introduction member 307 includes a base 371 connected to the connection switching member 308, yarn inlet pipes 378 and 378 ′ fitted to the base 371, and yarn inlets fitted to the yarn inlet pipes 378 and 378 ′. It consists of members 372 and 372 ′ and a mounting plate 373 to which a base 371 fitted with the yarn inlet members 372 and 372 ′ is screwed together with the yarn inlet pipes 378 and 378 ′. The mounting plate 373 is fixed to the sewing machine main body by screws.

  As described above, the base 371 is formed with the slide groove 371b with which the slide portion 385 of the connection switching member 308 engages and the corrugated notch 371a with which the projection 384 engages. Further, a spring 374 and a ball 375 are embedded in the base 371 on the side facing the knob portion 386, and the spring 374 presses the knob portion 386 via the ball 375, and the air supply port 381 of the connection switching member 308. , 382 side is urged so as to be in close contact with the base 371. Furthermore, the base 371 is provided with two substantially cylindrical recesses 376 and 376 'into which the yarn inlet members 372 and 372' are fitted.

  The recess 376 (same as 376 ′) is connected to the first hole 376a (376′a) into which the yarn inlet pipe 378 (378 ′) is inserted and the air supply port 381 (382) of the connection switching member 308. The second hole 376b (376′b) is provided (see FIGS. 17 and 18). When the connection switching member 308 is slid to the first position by the knob portion 386, the air supply port 381 is positioned so as to coincide with the second hole 376b of the one recess 376, and at this time, the air supply port 382 is The other recess 376 ′ is completely displaced from the second hole 376′b. When the connection switching member 308 is slid to the second position by the knob portion 386, the air supply port 382 is positioned so as to coincide with the second hole 376′b of the other recess 376 ′. The air supply port 381 is at a position completely deviated from the second hole 376 b of the recess 376. The upper end of the first hole 376a is cut into a conical shape so that the upper part of the yarn inlet pipe 378 is engaged.

  The yarn inlet pipe 378 (378 ′) has a funnel-shaped receiving portion at the top thereof for engaging with a conical portion cut at the top of the first hole 376a (376′a). The yarn inlet member 372 (372 ′) is engaged with the funnel-shaped receiving portion of the tube 378 (378 ′). Further, the lower end of the yarn inlet pipe 378 (378 ') is connected to the upper looper yarn conduit 305 (lower looper yarn conduit 306) by a connecting rubber 379 (379').

  The yarn inlet member 372 (372 ′) has a substantially cylindrical shape having a flange portion 372a having a diameter substantially equal to the diameter of the recess 376 (376 ′), and a yarn inlet for inserting the yarn into the center of the upper end thereof. 372b is formed, and a yarn introduction tube 372c is formed so as to penetrate the center of the cylinder continuously to the yarn inlet 372b.

  The base 371 in which the yarn inlet members 372 and 372 ′ are fitted via the yarn inlet pipes 378 and 378 ′ has an O-ring in a hole 373a in which the yarn inlets 372b and 372′b are formed in parallel to the mounting plate 373. It is screwed to the mounting plate 373 so as to be fitted through a sealing member as described above. The yarn inlets 372b and 372'b have a trumpet shape so that the yarn can be easily inserted.

  Further, the air flow path of the yarn inlet member 372 will be described. Since the yarn inlet member 372 'has the same configuration as the yarn inlet member 372, description thereof is omitted.

  The lower end of the yarn inlet member 372 has a conical shape that engages with the receiving portion of the yarn inlet pipe 378 that is fitted in the first hole 376a cut in the recess 376, and at least two or more on the outer surface of the cone. The gas introduction part 377 is formed. That is, each gas introducing portion 377 has an end portion opened to the yarn introducing tube 372 c at the center of the yarn inlet member 372. Therefore, when the air supply port 381 and the second hole 376 b communicate with each other, the air supplied from the air supply port 381 is branched into the plurality of gas introduction portions 377 through the space of the second hole 376 b and the recess 376. Is introduced into the yarn introduction pipe 372c.

  Here, when the pressurized air is extruded from each gas introduction part 377, the gas introduction part 377 opens with an acute angle with respect to the yarn introduction pipe 372c, so that the flow velocity in the direction of the arrow is fast near the outlet. Air flow is generated. Therefore, Bernoulli's theorem generates a force in the direction of the arrow on the yarn inlet side of the yarn introduction tube 372c, and the yarn inserted from the yarn inlet 372b is drawn into the upper looper yarn conduit 305 via the yarn inlet tube 378. . It is sent to the yarn outlet of the looper by the air flow having a high flow velocity from the gas introduction part 377. At this time, since the pressurized air is branched by the plurality of gas introduction portions 377 and introduced into the yarn introduction pipe 372c, the yarn inserted into the yarn introduction pipe 372c from the yarn inlet 372b is very efficiently handled by the upper looper yarn conduit 305. Can be sent to the side.

  When pressurized air is supplied from the yarn introduction pipe 372c to the upper looper yarn conduit 305, the air existing over a long distance from the upper looper yarn conduit 305 to the yarn outlet 30b of the upper looper 30 is resistant. In order to prevent the pressurized air from being pushed back, the amount of air supplied from the gas introducing portion 377 is such an amount that there is no such resistance and is smoothly discharged from the yarn outlet 30b, and the yarn is fed. It is desirable to have a sufficient flow rate. For this reason, the total pipe diameter d1 of the gas introduction part 377 is preferably d1 <d2 when the pipe diameter of the yarn introduction pipe 372c is d2, for example, the pipe diameter of the yarn introduction pipe 372c is 0.8 mm to When it is about 1 mm, d1 is preferably about 80%. By setting the total tube diameter of the gas introduction portion 377 in this way, a flow velocity sufficient to draw out the yarn with a relatively small amount of air can be obtained, and the resistance by the air in the middle can be suppressed and the upper looper yarn 3 can be smoothly conveyed to the yarn outlet 30b.

  As shown in FIGS. 15 and 16, the upper looper yarn conduit 305 and the lower looper yarn conduit 306 are arranged in a direction in which the yarn guide outlets 305b and 306b intersect with the moving surface drawn by the upper looper 30 and the lower looper 40. As shown, the upper looper yarn conduit guide 311 and the lower looper yarn conduit guide 312 fixed to the looper base 67 of the looper driving unit 60 are supported. Accordingly, the looper yarn inlets 30a, 40a of the upper looper 30 and the lower looper 40 are also arranged in the direction crossing the moving surface drawn by the upper looper 30 and the lower looper 40. The yarn inlets 30a and 40a can be matched with the yarn guide outlets 305b and 306b of the upper looper yarn conduit 305 and the lower looper yarn conduit 306. Since the looper yarn inlets 30a and 40a of the upper looper 30 and the lower looper 40 are formed in a trumpet shape (tapered wall surface), the upper looper yarn conduit 305 and the lower looper yarn conduit 306 are connected to the looper yarn inlets 30a and 40a. The center of the upper looper yarn conduit 305 and the lower looper yarn conduit 306 and the center of the looper (looper yarn pipes 301 and 401) can be eliminated and the centers can be made coincident with each other.

  Next, connection means for connecting the upper looper yarn conduit 305 and the lower looper yarn conduit 306 to the looper yarn inlets 30a and 40a of the upper looper 30 and the lower looper 40 will be described. As shown in FIGS. 4, 8, 9, 15, and 16, the coupling means includes a thread conduit dissociation lever 321, a thread conduit dissociation lever link 322, a dissociation lever base 323, a dissociation lever torsion spring 324, and a thread conduit dissociation. It is comprised by the nail | claw board 325 and the tension | pulling spring 326,327 for a thread | yarn conduit. One end of the yarn conduit dissociating lever 321 is disposed so as to be capable of being pressed against the direction of the yarn guide outlets 305 b and 306 b of the upper looper yarn conduit 305 and the lower looper yarn conduit 306, and the other end is a looper base 67 of the looper driving unit 60. The intermediate portion is pivotally attached to one end of the yarn conduit dissociating lever link 322 so as to be rotatable. Further, since the yarn conduit dissociation lever 321 always repels away from the upper looper yarn conduit 305 and the lower looper yarn conduit 306, the dissociation lever is provided between the yarn conduit dissociation lever 321 and the yarn conduit dissociation lever link 322. A torsion spring 324 is provided. Furthermore, the other end of the thread conduit disengagement lever link 322 is one end of a thread conduit disengagement claw plate 325 that is rotatably fixed to a convex portion 512 c formed on the hook mounting base 512 of the lock stitch / edge switch control unit 510. It is connected to.

  A thread conduit dissociating claw 325 a is formed at the other end of the thread conduit disengaging claw plate 325, and the thread conduit disengagement claw 325 a notched in the clutch switching plate 511 and the looper stop control plate 501 of the main sewing / edge overturning control unit 510 is formed. It is possible to engage with the separation cam 511d and the yarn conduit contact / separation timing cam 501c.

  The yarn conduit tension spring 326 (327) has one end fixed to the machine frame FR and the other end hooked to the upper looper yarn conduit 305 (lower looper yarn conduit 306). Therefore, the upper looper yarn conduit 305 (lower looper yarn conduit 306) always has the yarn guide outlets 305b and 306b moved by the elastic force of the yarn conduit tension spring 326 (327) and the looper yarns of the upper looper 30 and the lower looper 40 at all times. The inlets 30a and 40a can be pressed.

  According to the looper threading device 300 configured in this way, when the stitch selection of the stitch selecting device 130 is other than the edge stitching, the main stitch / edge guard switching control unit 510 automatically performs an operation other than the edge stitch. Since the switching control is performed, the looper threading device 300 can thread the upper looper thread 3 and the lower looper thread 4 through the upper looper 30 and the lower looper 40 in conjunction with the switching control.

  Further, the upper looper 30, the lower looper 40 and the upper looper yarn conduit 305, and the lower looper yarn conduit 306, that is, the looper yarn inlets 30a and 40a of the upper looper 30 and the lower looper 40, and the upper looper. Between the yarn conduit 305 and the yarn guide outlets 305b and 306b of the lower looper yarn conduit 306, a looper yarn balance 400 (see FIGS. 3, 4, and 15) as looper yarn supply means is provided. In this looper thread balance 400, the upper looper thread 3 and the lower looper thread 4 are interlocked with the movement trajectories of the upper looper 30 and the lower looper 40 in accordance with the switching control to the edge stitching of the main sewing / edge stitching switching control unit 510. The upper looper thread 3 and the lower looper thread 4 necessary for edge stitching when looped on the needle 10 are fed through an upper looper thread tensioner 35 and a lower looper thread tensioner 45 (see FIG. 1). After the needle 10 is pulled out from the upper looper thread 3 and the lower looper thread 4 and the upper thread 1 is tightened by the upper thread balance 16, the upper looper thread 3 and the lower looper that are retracted and stored are stored. The yarn 4 is supplied to the upper looper 30 and the lower looper 40.

  As shown in FIGS. 5 and 6, such a looper yarn balance 400 is such that when the upper looper 30 is lowered and the looper yarn inlet 30 a passes the yarn guide outlet 305 b of the upper looper yarn conduit 305, the upper looper yarn 3 is moved to the needle 10. Tightening of the upper looper thread 3 is started, and the upper looper 30 further descends and the upper looper thread 3 is completely tightened before the upper looper 30 reaches the bottom dead center and the needle 10 comes out of the workpiece. The upper looper yarn 3 is fed through the upper looper yarn tensioner 35 (see FIG. 1) and accumulated, and when the upper looper 30 starts to rise, the accumulated upper looper yarn 3 is released, and the upper looper 30 The upper looper that pulls the upper looper thread 3 so that tension is applied to the upper looper thread 3 when the needle 10 descends from the upper dead center and starts to descend when the needle 10 descends from the upper dead center. A thread balance 401 (see FIGS. 5A and 5B); When the looper 40 moves backward and the looper yarn inlet 40a passes through the yarn guide outlet 306b of the lower looper yarn conduit 306, the lower looper yarn 4 is entangled with the needle 10, and the lower looper yarn 4 is further tightened. After the lower looper thread 4 has been retracted and the tightening of the lower looper thread 4 has been completed, the lower looper thread 4 is retracted through the lower looper thread tensioner 45 (see FIG. 1) until the lower looper 40 reaches the final retraction point. A lower looper yarn balance 402 (see FIGS. 6A and 6B) that discharges the accumulated yarn when the looper 40 moves forward is provided. Thereby, in the edge stitching, when the needle 10 is pierced through the body to be sewn, the upper looper thread 3 and the lower looper thread 4 stored in advance by the upper looper thread tensioner 35 and the lower looper thread tensioner 45 are stored. Can be tightened.

  As shown in FIG. 4, the upper looper yarn balance 401 has a looper balance drive arm 404 having a shift drive cam groove 403 that is pivotally attached to a looper base 67 having one end fixed to the machine frame FR, and an inner portion of the shift drive cam groove 403. And a cam driver 405 provided on the lower looper driving arm 66 for shifting the looper balance driving arm 404 by the looper driving unit 60. On the other hand, the lower looper yarn balance 402 is provided at one end of the looper balance driving arm 404.

  Further, as shown in FIG. 20, the main sewing edge overlock sewing machine is provided on the needle plate 8 and is an openable / closable hatch that closes the opening 8b of the needle plate 8 in conjunction with the switching control of the main sewing / edge over switching control unit 510. 601 and the upper stitcher 30 when the upper looper 30 moves up and down the needle plate 8 in conjunction with the switching control to the edge stitching of the main sewing / edge switching control unit 510 (FIG. 20 (a)). A hatch opening / closing operation that drives the hatch 601 to open / close as shown in FIG. 20 (b) when the upper looper 30 is retracted to a fixed position in conjunction with the switching control to the main stitch by the edge switching control unit 510. Part 602.

  According to the hatch 601 configured as described above, when the stitch selection of the stitch selection device 130 is edge stitching, the main stitch / edge stitch switching control unit 510 automatically performs switching control to margin stitching. The hatch 601 provided on the throat plate 8 is opened when the upper looper 30 is moved up and down the throat plate 8 in conjunction with the switching control to the edge stitching of the main sewing / edge stitching switching control unit 510. In addition, according to the hatch opening / closing section 602, when the main sewing / edge overhang switching control section 510 is controlled to be switched to the main sewing, the hatch opening / closing is performed when the upper looper 30 is retracted to a fixed position below the needle plate 8. Since the portion 602 can automatically close the hatch 601, an operation for opening and closing the lid for closing the opening 8 b formed in the needle plate 8 in order to move the upper looper 30 up and down the needle plate 8 is performed. Can be omitted, also after removing the lid It is possible to save the trouble for accommodating managing the lid can prevent an accident of losing the lid.

  The hatch opening / closing section 602 is opened when the upper looper 30 moves up and down the needle plate 8 in conjunction with the switching control to the edge sewing by the main sewing / edge driving switching control section 510, and the main sewing / edge driving is performed. When the upper looper 30 is retracted to a fixed position in conjunction with the switching control to the main stitch of the switching control unit 510, the looper clutch 500 is completely disengaged and the power to the upper looper 30 is cut off to close the hatch 601. A hatch opening / closing spring 604 is provided so as to be interlocked with the lock stitch / edge switching control unit 510. More specifically, the hatch opening / closing spring 604 is fixed to a hatch opening / closing spring mounting plate 605 fixed to the other end of the looper stop control plate 501 of the main sewing / edge overhang control unit 510. A hatch opening / closing driving claw 604 a is formed at the tip of the hatch opening / closing spring 604, and is engaged with a hatch opening / closing claw 606 provided inside the hatch 601. Thereby, the hatch 601 can be automatically opened and closed by the elastic force of the hatch opening and closing spring 604 provided in the hatch opening and closing unit 602.

  In addition, the hatch 601 is seen in the sewing direction of cloth waste cut off at the time of the edge stitching of the upper looper thread 3 pierced by the upper looper 30 that moves up and down in the opening 8b formed when the hatch 601 is opened. A cloth guide plate 603 that forms the same plane as the throat plate 8 together with the hatch 601 is hinged when the hatch 601 is closed by preventing it from being guided to the right outward and falling into the opening 8b. This cloth waste guide plate 603 is elastically repelled at all times so that the hatch 601 can be supported when the hatch 601 is opened. Therefore, a torsion spring for hatch hinges is provided at the hinged portion between the cloth waste guide plate 603 and the hatch 601. 608 is provided. Further, the hatch 601 is provided with a hatch stopper 607 so that the hatch 601 is locked at that position when the hatch 601 is opened at a predetermined opening degree. The hatch stopper 607 is hooked on the end face of the opening 8b of the needle plate 8.

  The main sewing edge overlocking operation by the so-called home-use main sewing edge overlock sewing machine to which the sewing machine stitch forming apparatus configured as described above is applied will be described below.

  Here, as shown in FIG. 2, the stitches of the overlock stitches are composed of a main sewing portion 6 composed of an upper thread 1 and a lower thread 2, an upper looper thread 3 that is two looper threads, and a lower looper thread 4. It has an edge portion 7 and is formed by crossing the main sewing portion 6 and the edge portion 7 with each other. That is, the upper thread 1 and the lower thread 2 form stitches 1a and 2a parallel to the cloth surface on the upper and lower surfaces 5a and 5b of the cloth to be sewn, for example, the double-layered cloth 5, and The main sewing portion 6 is formed by forming a seam that crosses the vicinity of the center in the thickness direction and penetrates the cloth 5.

  On the other hand, the upper looper yarn 3 and the lower looper yarn 4 form an edge overhanging portion 7 that prevents fraying of the edge portion 5c of the cloth 5, crosses each other at the edge portion 5c of the cloth 5, and the upper looper yarn 3 Crosses the upper end of the main sewing portion 6 through the upper surface 5a of the cloth 5, and the lower looper thread 4 crosses the lower end of the main sewing portion 6 through the lower surface 5b of the cloth 5.

  In this way, the stitches of the main stitch edge are composed of the upper thread 1 that is one needle thread, the lower thread 2 that is the hook thread, and the two looper threads 3 and 4. The main stitching portion 6 formed by the thread 2 is crossed by the edge overhanging portion 7 formed by the looper yarns 3 and 4 on both sides of the cloth so that both the main sewing and the edge overhanging together constitute a stitch. ing.

  In such a main stitch edge sewing machine that forms a stitch formed by connecting both the main stitch and the edge stitch, when the sewer selects the edge stitch, the upper thread 1, the lower thread 2. Perform threading work to the upper looper thread 3 and lower looper thread 4, work to switch the stitches to the edge stitches, and work to switch the knife to the knife operating state.

  In the threading operation of the upper thread 1 and the lower thread 2, the upper thread 1 wound around the upper thread spool is hooked on the upper thread tensioner 15 and the upper thread balance 16 and passed through the needle 10, and the lower thread 2 is passed through the needle plate. It is pulled out from the hook (sword tip) 20 located below 8.

  Next, the threading operation of the upper looper thread 3 and the lower looper thread 4 is performed by the sewing person selecting items other than the edge stitches with the stitch switching knob NB. When the stitcher selects an item other than the edge stitches and rotates the stitch change knob NB, the stitch selection device 130 has a portion other than the recess 132a of the edge cam 132 fixed to the stitch selection shaft 131. Since one end of the stitch switching arm 133 is pushed up and the stitch switching arm 133 rotates counterclockwise in FIG. 8, the stitch switching rod 135 connected to the other end of the stitch switching arm 133 moves to the right. As a result, the clutch switching plate 511 of the lock stitch / edge switching control unit 510 connected to the stitch switching rod 135 moves to the right against the elastic force of the clutch switching tension spring 513. At this time, the looper stop control plate 501 also tries to move rightward against the elastic force of the looper stop control tension spring 514. However, the looper drive screw gear MT3 has a concave portion 505b and a looper base. When the looper drive screw gear stopper 503 fixed to the base 67 is not in the same position, they cannot be fitted, so that the looper stop control plate 501 does not move even by the elastic force of the looper stop control tension spring 514 ( FIG. 8, FIG. 9, FIG. This is because the looper stop control plate 501 is fixed to the convex portions 512a and 512b protruding from the lower surface of the hook mounting base 512 so that the looper stop control plate 501 is slidable by a predetermined length in the axial direction of the lower shaft S2. This is because the long holes 501d and 501e perforated to allow the clutch switching plate 511 to move.

  Therefore, if the upper looper 30 in which the concave portion 505b of the driving gear 505 and the looper drive screw gear stopper 503 are fitted rotates the hand pulley HP fixed to the upper shaft S1 to the timing position of the lowest point, the looper stop control is performed. Since the plate 501 moves rightward by the elastic force of the looper stop control tension spring 514, the L-shaped tip 501 a of the clutch switching link 501 fitted in the moving groove 505 a of the driving gear 505 causes the driving gear 505 to move. It can be moved to the right. As a result, the clutch pawl 505c of the driving gear 505 is disengaged from the clutch engaging recess 506a of the clutch receiver 506 fixed to the lower shaft S2, and the rotational movement of the lower shaft S2 is cut off, so that the driving gear 505 cannot rotate. Therefore, the upper looper 30 and the lower looper 40 of the looper driving unit 60 can be retracted to predetermined positions below the needle plate 8.

  In such a state, the yarn conduit contact / separation timing cam 501c of the looper stop control plate 501 and the yarn conduit contact / separation cam 511d of the clutch switching plate 511 are aligned and positioned in the right direction. Since the thread conduit dissociating claw 325a of the claw plate 325 falls into the cams 501c and 511d, the thread conduit dissociating lever link 322 connected to the thread conduit dissociating claw plate 325 connects the thread conduit dissociating lever 321 to the torsion spring 324 for dissociating lever. The upper looper yarn conduit 305 and the lower looper yarn conduit 306 are separated from each other against the elastic repellency. As a result, the upper looper yarn conduit 305 and the lower looper yarn conduit 306 move the yarn guide outlets 305b and 306b to the upper looper 30 and the looper yarn inlets 30a and 40a of the lower looper 40 by the elastic force of the tension springs 326 and 327 for the yarn conduit. Press contact. At this time, since the receiving portions of the looper yarn inlets 30a and 40a have a trumpet shape, the ends of the upper looper yarn conduit 305 and the lower looper yarn conduit 306 are naturally centered on the upper looper yarn pipe 301, It coincides with the center of the lower looper yarn pipe 401.

  Next, the knob portion 386 of the connection switching member 308 is slid left (or right), and one air supply port, for example, the left air supply port 381 is aligned with the hole 376b on the upper looper yarn conduit 305 side of the yarn introduction member 307. Like that. In this state, the upper looper yarn 3 wound around the upper looper yarn bobbin (not shown) at the upper looper yarn inlet 372b is passed through the upper looper yarn tensioner 35 to an appropriate length (about 1 cm). At the same time, the lever 304c of the air pump 304 is pushed down to send pressurized air to the upper looper yarn conduit 305. This flow of pressurized air creates a negative pressure that draws the yarn in the vicinity of the yarn introduction pipe 372c by Bernoulli's theorem, and simultaneously draws the upper looper yarn 3 inserted from the yarn inlet 372b into the upper looper yarn conduit 305. The flow of pressurized air sends the upper looper yarn 3 along the looper side of the upper looper yarn conduit 305, the upper looper yarn pipe 301 and the yarn conveyance path that continues from the upper looper yarn conduit 305, and sends it out from the sword tip 31 of the upper looper 30. If the yarn cannot be fed by a single press of the lever of the air pump 304, the threading can be reliably performed by repeating the operation two or three times.

  Next, the knob portion 386 of the connection switching member 308 is slid to the right so that the air supply port 382 is aligned with the hole 376 ′ b on the lower looper yarn conduit 306 side of the yarn introduction member 307. Here, the lower looper thread 4 wound around the lower looper thread spool (not shown) is inserted into the lower looper thread insertion port 372′b via the lower looper thread tensioner 45, and the lever of the air pump 304 is inserted. The lower looper thread 4 can be sent to the sword tip of the lower looper 40 at a stretch by pressing down 304c and pressurized air.

  In addition, not only an air pump but what kind of thing may be sufficient as long as it can send gas with a suitable flow volume.

  In the stitch switching operation, when the sewing operator rotates the stitch switching knob NB in order to select the edge stitch, the concave portion 132a of the edge cam 132 fixed to the stitch selection shaft 131 of the stitch selection device 130 is selected. Since one end of the seam switching arm 133 falls down, the seam switching arm 133 rotates clockwise in FIG. 8, so that the seam switching rod 135 connected to the other end of the seam switching arm 133 moves to the left. The clutch switching plate 511 of the main stitch / edge shift switching control unit 510 connected to the stitch switching rod 135 is moved to the left by the elastic force of the clutch switching tension spring 513. When the clutch switching plate 511 moves to the left, the looper stop control plate 501 also moves to the left by the elastic force of the looper stop control tension spring 514. Therefore, the moving groove of the driving side gear 505 of the looper drive screw gear MT3. The looper stop timing arm tip 501a of the looper stop control plate 501 fitted to 505a moves the driving gear 505 leftward, and the recess 505b of the driving gear 505 is disengaged from the looper driving screw gear stopper 503. The clutch pawl 505c of the driving gear 505 is engaged with the clutch engaging recess 506a of the clutch receiver 506 fixed to the lower shaft S2 (FIG. 9A). When the clutch engaging recess 506a of the clutch receiver 506 is in a position where the clutch pawl 505c of the driving gear 505 cannot be engaged, the clutch of the clutch receiver 506 fixed to the lower shaft S2 by rotating the hand pulley HP. The engaging recess 506a and the clutch pawl 505c of the driving gear 505 are engaged. As a result, the rotational movement of the lower shaft S2 is transmitted to the driven gear 509 via the driving gear 505, so that the upper looper 30 and the lower looper 40 of the looper driving unit 60 are driven.

  Further, since the yarn conduit contact / disengagement cam 511d of the clutch switching plate 511 is moved leftward, the yarn conduit dissociation claw 325a of the yarn conduit disengagement claw plate 325 of the connecting means is connected to the yarn conduit disengagement cam of the clutch switch plate 511. Since the thread conduit disengagement claw plate 325 is connected to the thread conduit disengagement claw plate 325, the thread conduit disengagement lever link 322 moves the thread conduit disengagement lever 321 over the upper looper by the elastic force of the disengagement lever torsion spring 324. The yarn conduit 305 and the lower looper yarn conduit 306 are pressed. As a result, the upper looper yarn conduit 305 and the lower looper yarn conduit 306 oppose the elastic force of the yarn conduit tension springs 326 and 327 so that the yarn guide outlets 305b and 306b pass through the upper looper 30 and the looper yarn inlet 30a of the lower looper 40. , 40a.

  Further, since the hatch opening / closing spring mounting plate 605 fixed to the other end of the looper stop control plate 501 moved to the left also moves to the left, the hatch opening / closing spring 604 fixed to the hatch opening / closing spring mounting plate 605 is shown in FIG. As shown in FIG. 20A, the hatch opening / closing driving claw 604a is separated from the hatch opening / closing claw 606 of the hatch 601, so that the hatch 601 and the cloth guide plate 603 are hatched by the elastic force of the torsion spring 606 for the hatch hinge. Is opened until it catches on the end face of the opening 8b of the needle plate 8.

  In the knife switching operation, when the cloth edge is cut and the edge stitching is performed on the main stitch, the knife driving unit 710 is in a knife non-operating state (a retracted position below the sewing machine arm) as shown in FIG. In this case, the knife driving unit 710 is brought into a knife operating state (an operating position on the needle plate 8) by a knob 715f formed on the knife unit base 715 of the knife driving unit 710. In other words, when the knob 715f is lowered, the upper swing arm 731 and the lower swing arm 732 of the four-joint rotation link 730 move downward while drawing an irregular elliptical locus, as shown in FIGS. Then, it smoothly moves to the operating position on the needle plate 8. At this time, the elasticity of the female retracting tension spring 736 stretched between the spring hook 731 a provided on the other end side of the upper swing arm 731 and the spring hook 735 provided on the lower side of the female unit mounting plate 734. Since the spring hook 731a of the upper swing arm 731 is locked to the first spring hook locking portion 734a of the female unit mounting plate 734 by the force, it is possible to prevent the female driving portion 710 from returning backward. Here, as shown in FIG. 25 (a), the positioning lever 718 of the knife driving unit 710 is lowered to a predetermined position, and the lower knife 73 is in the knife non-operating state in which the lower knife 73 is retracted to the retracted position by the lower knife mounting piece 713. If so, the positioning lever 718 is operated upward as shown in FIG. As a result, the lower knife 73 fixed to the lower knife mounting piece 713 having the groove 713b into which the convex portion 718b of the positioning lever 718 is fitted is lowered, and the positioning locking portion 87 of the lower knife 73 is moved to the needle. A knife operating state (FIG. 24) in which the knife driving unit 710 is positioned with respect to the needle drop position PS of the needle 10 by being fitted in the positioning recess 8 a of the plate 8 is obtained. At this time, the stopper convex portion 715e projecting from the female unit base 715 is fitted into the stopper concave portion 718d formed in the positioning lever 718 in a state where it can be detached with a predetermined force. Can be prevented.

  Thus, in the state in which the upper looper 30, the lower looper 40, the upper knife 72, and the lower knife 73 of the looper driving unit 60 can be driven, the main thread unit 6 drives the needle bar 1 that has been pierced by the needle 10. After passing through the cloth 5 following the vertical movement of the needle 10 by the portion MT1, when the needle 10 starts to rise from the bottom dead center, the sword tip 21 of the shuttle 20 scoops the upper thread 1 at the point R. When the upper thread 1 is pulled up by the needle 10 and the balance 16 that are further crossed over and the lower thread 2, the lower thread 2 is pulled up, and the above operation is repeated for each cloth feed. A continuous main sewing portion 6 is formed (FIG. 2).

  Further, when the upper looper 30 at the top dead center is reciprocated up and down by the upper looper mounting arm 63, the upper looper thread 3 is wound by the needle 10 at the point P on the way down. The upper end of the main stitching portion 6 and the upper looper thread 3 cross at the upper surface of the cloth (FIGS. 2, 5A and 5B). Next, when the lower looper mounting arm 65 is reciprocated left and right, the lower looper thread 4 of the lower looper 40 moving from the most protruding point to the last retracting point is beaten by the needle 10 that descends from the top dead center at the Q point. As a result, the lower end of the main sewing portion 6 and the lower looper thread 4 cross each other on the lower surface of the cloth (FIGS. 2, 6A, and 6B). Further, when the lower looper mounting arm 65 is reciprocated left and right, the lower looper thread 4 that is retracted to the last retracted point is raised from the bottom dead center by the upper looper mounting arm 63 at the point S. The upper looper yarn 3 and the lower looper yarn 4 cross each other at the edge portion 5c of the cloth 5 to form the edge overhang portion 7 (FIG. 2). The edge overhanging portion 7 is also repeated with one cloth feed as one cycle, whereby a stitch in which the edge overhanging portion 7 intersects for each stitch of the main sewing as shown in FIG. 27A is obtained. .

  As shown in FIGS. 7 and 26, the upper looper 30 and the lower looper 40 are driven by the L-shaped looper drive link 62 connected to the crank 61a when the crank 61a of the looper drive unit 60 rotates. Therefore, the upper looper mounting arm 63 connected to the long link end 62a of the L-shaped looper drive link 62 converts the constant speed rotation motion of the looper drive shaft 61 into the swing motion of the upper looper 30, while L The short link end 62b of the looper drive link 62 is restrained by a four-bar rotation chain formed by a crank 61a mounted on the looper drive shaft 61, an upper looper mounting arm 63, and a long link of the L-shaped looper drive link 62. Since a constant velocity elliptical motion is generated, the lower looper mounting arm 65 connected via the lower looper drive link 64 and the lower looper drive arm 66 rotates the looper drive shaft 61. Converting the dynamic unequal speed swinging movement of the lower looper 40.

Here, the upper looper mounting arm 63 reciprocates up and down between position A ₁ (upper looper 30 is bottom dead center) and position C ₁ (upper looper 30 is top dead center), and lower looper mounting arm 65 is at position B. ₃ (the lower looper 40 is the last retreat point) and the position D ₃ (the lower looper 40 is the forward movement point) reciprocating left and right, but the upper looper mounting arm 63 is the constant velocity of the coupling portion 62c of the L-shaped looper drive link 62 The lower looper mounting arm 65 is dominated by the rotational motion, and the lower looper 4 swings with respect to the upper looper 30 because the lower looper mounting arm 65 is dominated by the inconstant elliptical motion of the short link end 62 b of the L-shaped looper drive link 62. Exercise is performed (FIGS. 7 and 26). Thereby, when the front end portion of the upper looper 30 and the front end portion of the lower looper 40 cross each other, the upper looper 30 and the lower looper 40 can be easily designed so that they can be swung so as not to collide with each other.

  The upper looper yarn 3 and the lower looper yarn 4 supplied to the upper looper 30 and the lower looper 40 are loosened or tightened by the upper looper yarn balance 401 and the lower looper yarn balance 402 of the looper yarn balance 400. . Specifically, the upper looper yarn balance 401 and the lower looper yarn balance 402 of the looper yarn balance 400 are controlled by the cam action of the cam driver 405 and the speed change drive cam groove 403 provided on the lower looper drive arm 66. That is, due to this cam action, the upper looper yarn balance 401 causes the upper looper yarn 3 to be entangled with the needle 10 when the upper looper 30 descends and the looper yarn inlet 30a passes the yarn guide outlet 305b of the upper looper yarn conduit 305. After tightening of the looper thread 3 is started and the upper looper 30 is further lowered and the tightening of the upper looper thread 3 is completed, the upper looper thread 30 reaches the bottom dead center and before the needle 10 comes out of the sewing object, the upper looper thread The upper looper yarn 3 is fed through the tensioner 35 (see FIG. 1) and accumulated, and when the upper looper 30 starts to rise, the accumulated upper looper yarn 3 is released, and the upper looper 30 rises to raise the upper looper. When the descent is started after passing through the top dead center, the yarn pulling can be performed so that tension is applied to the upper looper thread 3 when the needle 10 hits the upper looper thread 3 while descending from the top dead center (FIG. 5). (Refer to (a) and (b)). Further, due to this cam action, the lower looper yarn balance 402 causes the lower looper yarn 4 to be entangled with the needle 10 when the lower looper 40 moves backward and the looper yarn inlet 40a passes the yarn guide outlet 306b of the lower looper yarn conduit 306. Tightening of the looper thread 4 is started, the lower looper 40 is further retracted, and after the thread tightening of the lower looper thread 4 is completed, the lower looper thread tensioner 45 (see FIG. 1) is operated until the lower looper 40 reaches the final retreat point. The lower looper yarn 4 is fed through and accumulated, and when the lower looper 40 moves forward, the accumulated yarn can be discharged (see FIGS. 6A and 6B). Thereby, in the edge stitch, when the needle 10 is pierced through the body to be sewn, the upper looper thread 3 and the lower looper thread 4 stored in advance by the upper looper thread tensioner 35 and the lower looper thread tensioner 45 are stored. Can be tightened.

  Further, the rotational motion of the rotary shaft of the sewing machine, in the illustrated example, the rotational motion of the upper shaft S1 is converted into a vertical motion through a motion conversion mechanism 71 linked thereto (FIGS. 1, 3, 11, 12, and 12). 13). That is, when the upper shaft S1 rotates, the links 77 and 78 of the first four-joint rotation chain LK1 are used as a crank, the link 80 is used as a connecting rod, and the link 79 is used as a rocker arm. As the link 79 swings, the link 81 of the second four-joint rotation chain LK2 swings, and the link 82, and hence the drive portion 751 of the clutch 75, moves up and down. The movement trajectory of the link 82 draws an elliptical trajectory by the four-joint rotation chain mechanisms LK1 and LK2, and draws an approximate straight line trajectory in the vertical direction at the suburb PL point of the drive unit 751 and is attached to the machine frame FR. The guide pin 754 that passes through the guide elongated hole and is fixed to the PL point of the link 82 supports the reaction from the knife driving unit 710. As a result, the movement of the drive unit 751 is restricted, and only the vertical movement is obtained with the stroke t (FIG. 12) for one rotation of the upper shaft S1.

  The vertically moving motion converted by the motion converting mechanism 71 is passed through a long groove 702 in which the pin 84 of the driving portion 751 of the clutch 75 and the pin 84 of the upper knife driving piece 711 as the driven portion 701 are fitted. Is transmitted to the upper knife 72. In the knife operating state (FIG. 24), the positioning locking portion 87 of the lower knife 73 is fitted in the positioning recess 8a of the needle plate 8 to position the knife driving portion 710 with respect to the needle drop position PS of the needle 10. The upper knife 72 is slidably guided by the guide groove 712a of the knife sliding body 712 through the upper knife spring plate 719 by the upper knife driving piece 711 pivotally supported by the machine frame FR. In this operating state of the knife, the knife driving unit 710 is maintained in a vertical state, and the longitudinal direction of the long groove 702 faces the horizontal direction, so that the pin 84 of the driving unit 751 of the clutch 75 and the long groove 702 of the driven unit 701 are transmitted with power. Power is transmitted to the upper knife 72 when the knife driving unit 710 operates, and the cloth edge 5c of the cloth 5 is cut by the upper knife 72 and the lower knife 73 cooperating with the upper knife by this vertical movement.

  By cutting the cloth edge 5c of the cloth 5 in this way and performing zigzag sewing or the like, the edge over stitching work can be performed in the same manner.

  Next, when the sewer selects the main stitch, the threading operation to the upper thread 1 and the lower thread 2, the stitch switching operation to the main stitch, and the cloth edge 5c of the cloth 5 are cut. If you want to perform only the main sewing without using the knife, switch the knife to the non-operating state.

  In the threading operation of the upper thread 1 and the lower thread 2, the upper thread 1 wound around the upper thread spool is hooked on the upper thread tensioner 15 and the upper thread balance 16 and passed through the needle 10, and the lower thread 2 is passed through the needle plate. It is pulled out from the hook (sword tip) 20 located below 8.

  In the stitch switching operation, when the sewing operator rotates the stitch switching knob NB to select the main stitch, the recess 132a of the edge cam 132 fixed to the stitch selecting shaft 131 of the stitch selecting device 130 is selected. One end of the seam switching arm 133 is pushed up to the other part, and the seam switching arm 133 rotates counterclockwise in FIG. 8, and therefore, the seam switching rod 135 connected to the other end of the seam switching arm 133. Is pulled in the right direction, and the clutch switching plate 511 of the lock stitch / edge switching control unit 510 connected to the stitch switching rod 135 is moved in the right direction against the elastic force of the clutch switching tension spring 513. Move to. At this time, the looper stop control plate 501 also tries to move rightward against the elastic force of the looper stop control tension spring 514. However, the looper drive screw gear MT3 has a concave portion 505b and a looper base. When the looper drive screw gear stopper 503 fixed to the base 67 is not in the same position, they cannot be fitted, so that the looper stop control plate 501 does not move due to the elastic force of the looper stop control tension spring 514 (see FIG. 8, FIG. 9 and FIG. 10). This is because the looper stop control plate 501 is fixed to the convex portions 512a and 512b protruding from the lower surface of the hook mounting base 512 so that the looper stop control plate 501 is slidable by a predetermined length in the axial direction of the lower shaft S2. This is because the long holes 501d and 501e perforated to absorb the movement of the clutch switching plate 511.

  Therefore, if the upper looper 30 in which the concave portion 505b of the driving gear 505 and the looper drive screw gear stopper 503 are fitted rotates the hand pulley HP fixed to the upper shaft S1 to the timing position of the lowest point, the looper stop control is performed. Since the plate 501 moves rightward by the elastic force of the looper stop control tension spring 514, the L-shaped tip 501 a of the clutch switching link 501 fitted in the moving groove 505 a of the driving gear 505 causes the driving gear 505 to move. It can be moved to the right. As a result, the clutch pawl 505c of the driving gear 505 is disengaged from the clutch engaging recess 506a of the clutch receiver 506 fixed to the lower shaft S2, and the rotational movement of the lower shaft S2 is cut off, so that the driving gear 505 cannot rotate. Therefore, the upper looper 30 and the lower looper 40 of the looper driving unit 60 can be retracted to predetermined positions below the needle plate 8.

  Further, since the hatch opening / closing spring mounting plate 605 fixed to the other end of the looper stop control plate 501 moved to the right also moves to the right, the hatch opening / closing spring 604 fixed to the hatch opening / closing spring mounting plate 605 is shown in FIG. As shown in (b), the hatch opening / closing claw 606 of the hatch 601 is pulled by the hatch opening / closing driving claw 604a to close the hatch 601. At this time, the cloth waste guide plate 603 hinged to the hatch 601 also forms the same surface as the needle plate 8 together with the hatch 601 against the elastic force of the torsion spring 608 for the hatch hinge. Thereby, cloth waste can be prevented from falling into the opening 8b of the needle plate 8 and adversely affecting the upper looper 30, the lower looper 40, and the like.

  In the knife switching operation, when only the main sewing is performed without cutting the cloth edge 5c of the cloth 5, the knife driving unit 710 is in the knife operating state (operating position on the needle plate 8) as shown in FIG. If so, the positioning lever 718 is operated downward. As a result, the lower knife 73 fixed to the lower knife mounting piece 713 is raised, and the positioning locking portion 87 of the lower knife 73 is released from the state of being fitted into the positioning recess 8 a of the needle plate 8. (See FIG. 25). Then, the knife driving unit 710 is brought into the non-operating state (the retracted position below the arm of the sewing machine) by a knob 715f formed on the knife unit base 715 of the knife driving unit 710. That is, when the knob 715f is lowered upward, as shown in FIGS. 24, 23, and 22, the upper swing arm 731 and the lower swing arm 732 of the four-joint rotation link 730 move upward while drawing an irregular elliptical locus. Then, it moves smoothly to the retracted position under the arm of the sewing machine. At this time, the elasticity of the female retracting tension spring 736 stretched between the spring hook 731 a provided on the other end side of the upper swing arm 731 and the spring hook 735 provided on the lower side of the female unit mounting plate 734. Since the spring hook 731a of the upper swing arm 731 is locked to the second spring hook locking portion 734b of the female unit mounting plate 734 by the force, the female driving portion 710 can be prevented from returning backward. As a result, the longitudinal direction of the long groove 702 of the driven portion 701 is oriented in the vertical direction, so that the pin 84 of the drive portion 751 of the clutch 75 only moves freely in the long groove 702 of the driven portion 701 and cuts off the power to the upper knife 72. Can do.

  The cloth edge of the cloth 5 can be easily operated by the knob 715f of the knife unit base 715 for moving the knife driving section 710 from the knife operating position in the vertical state to the knife retracting position in the horizontal state by drawing an irregular elliptical locus. It is possible to smoothly switch to the operation of performing only the main sewing without cutting 5c.

  As a result, the main sewing can be executed.

  In addition, according to the preferred embodiment in which the stitch forming device of the sewing machine of the present invention is applied to a home-use main stitch sewing machine, a horizontal shuttle that performs a horizontal rotational movement is used. When the upper thread pierced by the needle is lifted from the bottom dead center of the needle, the upper stitch and the lower thread are crossed, and the main stitch part is composed of a seam parallel to the surface of the workpiece and a vertical seam. Any pot may be used as long as it can be formed.

  In addition, the knife drive unit of the knife drive mechanism is not limited to the one described above, and a positioning lever that slidably attaches the lower knife and fits the positioning locking part of the lower knife into the positioning recess of the needle plate when the knife is activated. Any structure may be used as long as it can be provided.

  Furthermore, in the above embodiment, the upper looper thread 3 and the lower looper thread 4 intersect with all the adjacent main sewing parts 6, but every other main sewing part 6 as shown in FIG. 27 (b), for example. The edge portions 7 may cross each other. In this case, the ratio of the rotational speeds of the lower shaft S2 and the looper driving unit 60 may be set so that the upper looper 30 and the lower looper 40 move by one cycle of the two cycles of the needle 10. .

  In the above embodiment, the stitches 1a and 2a of the upper thread 1 and the lower thread 2 are each linear, but each stitch may be zigzag as shown in FIG. Each stitch may be folded.

  Further, the sewing machine for forming a sewing machine according to the present invention is not limited to a home-use main-edge sewing machine as in the above embodiment, but can be applied to an industrial-use main-edge sewing machine.

  The industrial edge stitch sewing machine was placed on the throat plate by the upper thread pierced by the needle moving up and down in a vertical direction with respect to the throat plate and the lower thread stored in the hook. When the upper thread that penetrates the sewing body and penetrates the needle that reciprocates in the vertical direction is lifted from the bottom dead center of the needle, the lower thread is placed below the needle plate. The main stitching part consisting of the seam parallel to the surface of the sewing object and the vertical seam is formed by crossing the upper thread and the lower thread with the sword tip of the hook that is stored and rotated. The upper and lower loopers intersect with the needle trajectory above the needle plate and the lower looper intersects the needle trajectory and the upper looper trajectory. The sewing machine has a stitch forming device for forming an edge stitched portion with the upper looper thread and the lower looper thread passed through.

  The sewing machine stitch forming apparatus is provided with a looper thread balance 400 as looper thread supply means having an upper looper thread balance 401 and a lower looper thread balance 402 as shown in FIGS. Thereby, when the needle is pierced through the sewing object, the upper looper thread 3 and the lower looper thread 4 stored in advance by the looper thread balance 400 can be tightened. 4, 5, and 6, the upper looper thread balance 401 is composed of a looper balance drive arm 404 and a cam driver 405, and the lower looper thread balance 402 is provided at one end of the looper balance drive arm 404. As a result, the upper looper yarn balance 401 and the lower looper yarn balance 402 can be driven and controlled only by the cam driver 405 that is driven to change speed by the looper drive unit 60.

  In addition, a crank 61a, an L-shaped looper driving link 62, an upper looper mounting arm 63, a lower looper driving link 64, and a lower looper mounting arm 65 as shown in FIGS. A looper driving unit 60 is provided. As a result, when the crank 61a of the looper drive unit 60 rotates, the L-shaped looper drive link 62 connected to the crank 61a is driven, so that the L-type looper drive link 62 is connected to the long link end 62a. The formed upper looper mounting arm 63 converts the rotational movement of the looper driving shaft 61 into the swinging movement of the upper looper 30, while the short link end 62 b of the L-shaped looper driving link 62 is a crank attached to the looper driving shaft 61. 61a, the upper looper mounting arm 63 and the long link of the L-shaped looper drive link 62 are restrained by the four-bar rotation chain and generate an inconstant elliptical motion, so that they are connected via the lower looper drive link 64. The lower looper mounting arm 65 converts the rotational motion of the looper drive shaft 61 into the unequal velocity swing motion of the lower looper 40. Therefore, when this looper drive part 60 drives and the front-end | tip part of the upper looper 30 and the front-end | tip part of the lower looper 40 cross, it can be made not to collide.

  Further, the stitch forming device for the sewing machine includes a looper threading device 300 having a threading air pump 304 as shown in FIGS. At this time, in the industrial main sewing edge overlock sewing machine, since it is a mechanism that always performs edge over stitching, the upper looper mounting arm shaft 600 and the lower looper mounting arm shaft 69 in FIG. Thus, the looper threading device 300 is used as the looper thread entrance of the upper looper 30 and the lower looper 40, so that the looper threading device 300 has the thread guide outlets 305b of the hollow thread guides 305 and 306 for the upper looper 30 and the lower looper 40, The looper yarn entrances of the upper looper 30 and the lower looper 40 can be always matched with 306b. In this matched state, by the threading air pump 304, from the introduction port of each hollow thread guide 305, 306 toward the thread guide outlets 305b, 306b, the upper looper 30, the looper thread inlet of the lower looper 40, the looper blade tip thread outlets 30b, 40b. The upper looper yarn 3 and the lower looper yarn 4 can be sent out, and the upper looper 30, the looper yarn inlet of the lower looper 40 and the processing and assembly for matching the yarn guide outlets 305b and 306b of the yarn guides 305 and 306, Adjustment becomes easy.

  1, 3, 11, and 14, the knife driving mechanism 70 draws a trajectory in a direction perpendicular to the needle plate and pierces the needle that moves up and down and the lower thread stored in the hook. When the upper thread pierced through the needle that reciprocates in the vertical direction through the sewing body every time the sewing body placed on the needle plate by the thread is raised from the bottom dead center of the needle, From the seam parallel to the surface of the body to be sewn and the perpendicular seam The present invention can also be applied to a home-use main sewing machine provided with a sewing machine stitch forming device for performing main sewing such as straight stitching and zigzag sewing. As a result, the knife cutting mechanism can be compactly incorporated into the existing structure space of the sewing machine, and the main sewing can be performed without cutting the cloth edge and performing the edge stitching to the main sewing without cutting the cloth edge. The work to be performed can be easily switched and executed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall perspective view showing an example of a preferred embodiment in which a stitch forming device for a sewing machine according to the present invention is applied to an overlock sewing machine. (A), (b) is explanatory drawing which shows simply the operation | movement of the main stitch edge sewing machine to which the stitch formation apparatus of the sewing machine of this invention is applied. The block diagram which shows the drive system of the main stitch edge sewing machine to which the stitch formation apparatus of the sewing machine of this invention is applied. The disassembled perspective view which shows the looper drive part in the stitch formation apparatus of the sewing machine of this invention. It is explanatory drawing which shows the operation state of the looper drive part in the stitch formation apparatus of the sewing machine of this invention, (a) is a figure when an upper looper is a top dead center, (b) is when an upper looper is a bottom dead center. Figure. FIG. 5 is an explanatory view showing an operating state of a looper driving unit in the stitch forming device of the sewing machine according to the present invention, where (a) is a view when the lower looper is the most protruding point, and (b) is a view when the lower looper is the last retracted point Figure. The movement mechanism figure which shows the operating state of the looper drive part in the stitch formation apparatus of the sewing machine of this invention. The disassembled perspective view which shows the looper clutch in the stitch formation apparatus of the sewing machine of this invention, and a main sewing and edge overhanging control part. FIG. 2 is a diagram illustrating an operating state of a looper clutch and a main sewing / edge-shift switching control unit in the stitch forming device of the sewing machine according to the present invention, where (a) is a diagram of a main-sewing / edge-locking state, and (b) is a main-sewing state. Illustration. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram showing an operating state of a looper clutch in a stitch forming device for a sewing machine according to the present invention, where FIG. The figure of the state which interrupted | blocked the motive power to a shaft. The perspective view which shows the knife drive mechanism in the stitch formation apparatus of the sewing machine of this invention. (A), (b) is explanatory drawing which shows the action | operation state of the motion conversion mechanism in the knife drive mechanism of the stitch formation apparatus of the sewing machine of this invention. Explanatory drawing which shows operation | movement of the motion conversion mechanism in the knife drive mechanism of the stitch formation apparatus of the sewing machine of this invention. The disassembled perspective view which shows the knife drive part and the 4-joint rotation link in the knife drive mechanism of the stitch formation apparatus of the sewing machine of this invention. The perspective view which shows the looper threading apparatus in the stitch formation apparatus of the sewing machine of this invention. The disassembled perspective view which shows the looper threading apparatus in the stitch formation apparatus of the sewing machine of this invention. FIG. 3 is a detailed view showing a relationship between a thread introduction member and a connection switching member of a looper threading device in the stitch forming device for a sewing machine of the present invention. (A), (b) is explanatory drawing which shows the thread | yarn introduction member of the looper threading apparatus in the stitch formation apparatus of the sewing machine of this invention. The disassembled perspective view which shows the thread | yarn introduction member and connection switching member of a looper threading apparatus in the stitch formation apparatus of the sewing machine of this invention. It is explanatory drawing which shows the hatch opening-and-closing part in the stitch formation apparatus of the sewing machine of this invention, (a) is a figure of a hatch opening state, (b) is a figure of a hatch closing state. The perspective view which shows the action | operation state of the 4-joint rotation link of the knife drive mechanism in the stitch formation apparatus of the sewing machine of this invention. The perspective view which shows the operation state of the 4-joint rotation link of the knife drive part in the stitch formation apparatus of the sewing machine of this invention. The perspective view which shows the operation state of the 4-joint rotation link of the knife drive part in the stitch formation apparatus of the sewing machine of this invention. The perspective view which shows the action | operation state of the 4-joint rotation link of the knife drive mechanism in the stitch formation apparatus of the sewing machine of this invention. It is explanatory drawing which shows the knife drive part in the stitch formation apparatus of the sewing machine of this invention, (a) is a figure which shows a knife non-operation state, (b) is a figure which shows a knife operation state. FIG. 4 is an operational state diagram of the looper driving unit in the stitch forming device of the sewing machine according to the present invention, where (a) is an explanatory diagram showing the relationship between the upper looper and the lower looper when the upper looper is raised, and (b) is the upper view. Explanatory drawing which shows the relationship between the upper looper and the lower looper when the looper is descending. FIG. 5 is a view showing stitches formed by a main stitch edge stitching machine to which the sewing machine stitch forming device of the present invention is applied, and (a) is an explanatory diagram of stitches at which a margin portion crosses every stitch of the main stitch portion; (B) is an explanatory diagram of the seams where the edge portions intersect every other or every two main stitches, and (c) is a zigzag shape for each stitch of the main stitch, or a plurality of stitches Explanatory drawing of the stitch which becomes a broken line shape every time. The perspective view which shows the structure of the main sewing edge overhang attachment used attaching to the sewing machine for main sewing.

Explanation of symbols

1 ... Upper thread 2 ... Lower thread 3 ... Upper looper thread 4 ... Lower looper thread 6 ... Main sewing part 7 ... Edge edge 8 ... Needle plate 10 ... Needle 16 ······················································································································································································································································································· Lower looper 40a Looper thread inlet 40b Looper blade tip thread outlet 45 Lower looper thread tensioner 60 Looper drive 61 61 Looper drive shaft 61a Looper drive shaft 62 L-shaped looper drive link 62a Long link end 62b Short link end 63 ... Upper looper mounting arm 64 ... Lower looper driving link 65 ... Lower looper mounting arm 71 ... Motion Conversion mechanism 72 ... Upper knife 73 ... Lower knife 75 ... Mescula 110 ... Needle drop control unit 130 ... Stitch selection device 300 ... Looper threading device 304 ... Threading air pump 305 ... Upper looper thread conduit (hollow thread guide)
305b ... Yarn guide outlet 306 ... Lower looper thread conduit (hollow thread guide)
306b ... thread guide outlet 400 ... looper thread balance (looper thread supply means)
401 ··························································································································································· Sewing / edge-over switching control section 601 ... Hatch 602 ... Hatch opening / closing section 603 ... Cloth waste guide plate 604 ... Hatch opening / closing spring 710 ... ... Female drive section 730 ... 4-node rotating link FR ... Machine frame S1 ... Upper shaft (rotating shaft)
L10 ... Trajectory of the needle L30 ... Arc-shaped trajectory of the upper looper L40 ... Arc-shaped trajectory of the lower looper

Claims (2)

Each time the workpiece to be sewn placed on the throat plate is fed by an upper thread pierced by a needle that moves up and down in a vertical direction with respect to the throat plate and a lower thread stored in the hook. When the upper thread pierced by the needle reciprocating vertically through the sewing body is lifted from the bottom dead center of the needle, the lower thread is stored below the needle plate and rotationally moved. The upper thread and the lower thread are crossed with the sword tip of the hook to cross to form the main stitching part such as straight stitches and zigzag stitches composed of seams parallel to the surface of the sewing object and vertical stitches. A reciprocating motion that draws a locus above and below the needle plate, an upper looper that intersects with the needle locus above the needle plate, a locus below the needle plate, and a locus of the needle and the upper looper The upper looper thread passed through the lower looper that crosses the trajectory of each, and the edge loop sewing with the lower looper thread Forming stitches of the sewing machine for controlling the needle drop of the needle and controlling the cloth feed of the workpiece according to the stitch selection of the stitch selection device that switches to the sewing mode of the main stitch or the edge stitching A device,
A cloth edge of the sewing object by an upper knife that moves up and down via a motion conversion mechanism that interlocks with a rotating shaft that drives the needle, and a lower knife that slidably guides the upper knife and cooperates with the upper knife. An irregular elliptical trajectory between the operating position on the throat plate when the knife is operated and the retracted position below the arm of the sewing machine when the knife is not operated is provided by a four-joint rotary link having different internode lengths. Pivot to the machine frame to draw and change,
The movement converting mechanism is configured such that the knife driving unit transmits a vertical movement to the upper knife at the operating position, and a knife clutch that blocks the vertical movement to the upper knife at the retracted position. A stitch forming device for a sewing machine, characterized in that it is connected. Each time the workpiece to be sewn placed on the throat plate is fed by an upper thread pierced by a needle that moves up and down in a vertical direction with respect to the throat plate and a lower thread stored in the hook. When the upper thread pierced by the needle reciprocating vertically through the sewing body is lifted from the bottom dead center of the needle, the lower thread is stored below the needle plate and rotationally moved. The upper thread and the lower thread are crossed with the sword tip of the hook, and the main stitches such as straight stitches, zigzag stitches and the like are formed by stitches parallel to the surface of the workpiece and perpendicular stitches. A sewing machine for a sewing machine,
A cloth edge of the sewing object by an upper knife moving up and down via a motion conversion mechanism interlocking with a rotation shaft that drives the needle and a lower knife that slidably guides the upper knife and cooperates with the upper knife. An irregular elliptical trajectory between the operating position on the needle plate when the knife is in operation and the retracted position below the arm of the sewing machine when the knife is not operated is provided by a four-joint rotary link having a different internode length. Pivot to the machine frame to draw and change,
The movement converting mechanism is configured such that the knife driving unit transmits a vertical movement to the upper knife at the operating position, and a knife clutch that blocks the vertical movement to the upper knife at the retracted position. A stitch forming device for a sewing machine, characterized in that it is connected.

Images