JP5057303B2 - Sewing machine with upper decoration mechanism - Google Patents

Description

  The present invention is applied to, for example, a multi-needle flat stitch sewing machine such as a three-needle, and is configured to form a seam with a plurality of needle threads, a looper thread and an upper decoration thread. The present invention relates to a sewing machine with a decoration mechanism.

  Conventionally, this type of sewing machine with a top decoration mechanism is fixed to and supported by a plurality of needles, a presser foot, and a sewing machine arm that are arranged in parallel in the direction crossing the cloth feed direction and can be reciprocated up and down. An upper decorative thread guide for guiding the decorative thread from above toward the stitch formation region under the presser foot, and a thread for hooking the upper decorative thread portion positioned between the upper decorative thread guide and the presser foot An upper thread looper that has a hook part and is provided so as to be movable forward and backward in the parallel direction of the plurality of needles so as to feed out the upper thread hooked on the thread hook part in a direction crossing the cloth feeding direction. And at the end of sewing, the needle reaches the top dead center or the vicinity thereof, and the upper decorative thread looper is moved to the advanced end, and the thread hooking portion of the upper decorative thread looper and the upper decorative thread guide Hang the upper decorative yarn part stretched between and diagonally backward Cut attracted toward, and that a cover thread cutting device on which holds the yarn end of the cover thread on which is the cutting have been proposed (e.g., see Patent Documents 1 to 3).

  According to the sewing machine with the upper decoration mechanism provided with the above-described structural members, the upper part extends obliquely upward to the right from the stitch formation area under the presser foot through the upper decoration thread guide during normal sewing operation. As the upper thread looper moves forward, the decorative thread is hooked to the thread hook of the looper and pulled to the left, and when the looper reaches the advanced end, the thread hook and the upper thread guide The needle on the left side in the parallel direction among the plurality of needles moves down in the upper decoration thread loop formed between the two and the needle on the right end in the parallel direction moves down on the front side of the upper decoration thread loop, When the looper is subsequently moved in and out, the upper decoration thread released from the thread hook is pushed down to the stitch formation area under the presser foot by the right end needle thread supplied to the right end needle. Configured to be sewn on the upper surface to form a predetermined stitch It has been.

  Japanese Patent Publication No. 61-11636   JP-A-4-354799   Japanese Examined Patent Publication No. 7-38914

  By the way, in all of the conventional sewing machines with an upper cover mechanism proposed in Patent Documents 1-3, the upper thread is hooked on the thread hook when the upper thread looper moves forward, and is pulled to the left. When the looper reaches the advancing end, the upper loop is reliably and stably formed between the thread hook and the upper thread guide, thereby releasing the hook from the loop hook. The upper decorative thread is repeatedly pushed down to the stitch formation area under the presser foot by the rightmost needle thread, so that a predetermined stitch can be formed continuously and reliably, that is, a normal sewing operation can be performed. This is based on the premise that the sewing operation can be normally performed from the sewing operation of the first stitch, and the first stitch forming operation (hereinafter referred to as the first stitch forming operation) when the sewing for the previous cloth is completed and the sewing for the next cloth is started. All stitches) It has not been taken into account. That is, it is not assumed that the upper decoration thread is not reliably hooked on the thread hook portion of the upper decoration looper during the sewing operation of the first stitch. Therefore, when a situation occurs in which the upper garment thread is not hooked on the thread hook portion of the upper garment looper during the sewing operation of the first stitch, a predetermined stitch in which the upper garment thread is entangled with the needle thread is not formed. As a result, the stitches are skipped, and the predetermined stitches cannot be formed during the sewing operation from the second stitch onward as well as the first stitch. As a result, there is a possibility that a defective sewing product may be generated.

In a conventional sewing machine with a top decoration mechanism, the reason why a predetermined stitch is not formed by the stitching operation of the first stitch and a stitch skip occurs will be described in detail with reference to an illustration of the main part as follows.
That is, at the end of sewing after the sewing work for the previous cloth is completed, as shown in FIG. 7A, the upper decorative thread fixedly supported by the thread hooking portion 1a of the upper decorative thread looper 1 and the sewing machine arm (not shown). A portion of the upper decorative yarn 3 stretched between the guide guide long hole 2a of the guide 2 is hooked on the movable knife 4a of the upper decorative yarn cutting device 4 and is pulled obliquely rearward and upward to be cut. In addition, the cut ends of the upper decorative yarn 3 are held and supplied to a plurality of needles 5L, 5M, and 5R (shown as three) arranged in parallel in the direction crossing the cloth feeding direction. The needle threads 6L, 6M, 6R are cut below the presser foot by a well-known thread trimming device (not shown). In some cases, the ends 61, 6m of the needle threads 6L, 6M, 6R after cutting are cut. , 6r is a needle thread wiper that moves approximately horizontally along the upper surface of the presser foot Ipa (for well-known in which, according to omitted) is withdrawn from the cloth presser foot of the eyelet by following insertion needle so as not to interfere 5L fabric, it is paid 5M, laterally above the 5R. At this time, the relationship between the needle thread 6R inserted through the needle hole of the right end needle 5R and the upper decoration thread 3 among the parallel needles 5L, 5M, 5R is as shown in FIG. 9A. The end 6r of the yarn 6R is positioned in a free end state behind the upper decorative yarn 3, that is, behind the cloth 20 in the feed direction X.

  When the sewing machine is actuated in this state and sewing on the next cloth 20 is started, as shown in FIG. 7B, the upper garment looper 1 moves back and forth from its advanced end position, and the needle clamp 7 is moved downward in synchronism with the needles 5L, 5M, 5R, and as shown in FIG. 7 (C), the upper thread looper 1 has its retracted end. Then, the needles 5L, 5M, 5R move forward in the parallel direction of the needles 5L, 5M, 5R, and the needles 5L, 5M, 5R and the upper thread passage 8 move upward after reaching the bottom dead center. At this time, the ends 61, 6m, and 6r of the needle threads 6L, 6M, and 6R cut below the presser foot or paid to the upper side of the needles 5L, 5M, and 5R after cutting are the presser foot. 9B, the free ends of the needle threads 6L, 6M, and 6R are moved as the needles 5L, 5M, and 5R move downward as shown in FIG. 9B. The portions 61, 6m, and 6r are pulled down below the position where the upper decorative yarn 3 is stretched.

  Next, it is only necessary that the upper decoration thread looper 1 can be hooked with the upper decoration thread 3 when the upper decoration thread looper 1 moves forward. In practice, however, the needle is set so that a good stitch can be formed. 5L, 5M, 5R and the operation timing of the upper thread looper 1, the upper thread path 8 rises before the thread hooking portion 1a hooks the upper decorative thread 3 part. As shown in FIG. 7C, the upper decorative yarn 3 is pulled up slightly above the moving path of the yarn hooking portion 1a of the upper decorative yarn looper 1 as it rises. Even if the three portions are not hooked on the yarn hooking portion 1a of the upper decorative yarn looper 1, or even if they are hooked, the probability is very unstable, and the upper decorative yarn looper 1 has reached the advancing end. When, as shown in FIG. 7 (D), the thread hook 1a and the upper thread guide 2 As shown in FIG. 9C, the upper end yarn loop 6R is formed at the lower end 6r of the right end needle yarn 6R as the needles 5L, 5M, 5R rise. The end 6r of the needle thread 6R after being captured by the lower looper thread looper 19 is positioned in front of the upper decoration thread 3 while being pulled down by the lower looper thread looper 19. FIG. 8 shows an enlarged view of FIG. 7D in order to make the state of FIG. 7D easier to understand.

  In such a situation, even if the needles 5L, 5M, and 5R are once lowered and the ends 6l, 6m, and 6r of the needle threads 6L, 6M, and 6R are connected to and held by the cloth 20 below the presser foot. The upper decoration thread 3 continues to be positioned in front of the left end and the end portions 6l and 6m of the middle needle threads 6L and 6M and behind the end portion 6r of the right end needle thread 6R, and the next needle 5L, During the downward movement of 5M and 5R, the upper decoration thread 3 cannot be pushed down below the presser foot by the right end needle thread 6R. Therefore, even if the stitches of the needle threads 6L, 6M, 6R and the lower looper thread are formed, a predetermined stitch entangled with the upper decorative thread 3 cannot be formed, and the sewing operation of the first stitch is performed. Of course, there is a problem in that a predetermined stitch is not formed even in the subsequent sewing operation, and a defective sewing product is generated.

  In particular, even when the cut end portion of the needle thread is not paid upward in the lateral direction, when the needle threads 6L, 6M, 6R having excellent stretchability are used, the needle thread 6L, Since the ends 6l, 6m, and 6r are shortened by shortening 6M and 6R, the positional relationship between the needle threads 6L, 6M, and 6R and the upper decoration thread 3 is shown in FIGS. 7D and 9C. In this state, it is more difficult to push down the upper decoration thread 6 to the stitch formation area under the presser foot, and a predetermined stitch can be formed during the first stitch and the subsequent stitching operations. I can't do it at all.

  The present invention has been made in view of the above-described circumstances, and reliably and stabilizes the hooking and holding of the upper garment thread by the upper garment looper during the sewing operation of the first stitch, so that the cut end of the needle thread at the end of sewing is obtained. It is an object of the present invention to provide a sewing machine with an upholstery mechanism that can reliably and smoothly form a predetermined stitch from the first stitch regardless of the condition of the section and the type of needle thread to be used.

  In order to achieve the above object, a sewing machine with an upper decoration mechanism according to the first aspect of the present invention includes a plurality of needles arranged in parallel in a direction crossing the cloth feeding direction and capable of reciprocating up and down, a cloth presser foot, An upper thread guide that is fixedly supported by the sewing machine arm and guides the upper thread from above toward the stitch formation area under the presser foot, and is positioned between the upper thread guide and the presser foot. The upper thread is hooked to the upper hook thread, and the upper needle thread hooked on the thread hook is advanced and retracted in the parallel direction of the plurality of needles so as to be fed out in the direction crossing the cloth feed direction. An upper decoration thread looper provided freely, and the needle has reached the top dead center or its vicinity at the end of sewing, and the upper decoration thread looper is moved to the advanced end. The upper decoration stretched between the thread hook and the upper decoration thread guide In a sewing machine with an upper decoration mechanism, the sewing machine includes an upper decoration thread cutting device that hooks a portion, draws it obliquely rearward and upward and cuts, and holds an upper decoration thread cutting device that holds the thread end of the cut upper decoration thread. Accordingly, when the upper decorative yarn looper moves back and forth from the advanced end position and reaches the vicinity of the retracted end, the upper decorative yarn looper is stretched between the upper decorative yarn cutting device and the upper decorative yarn guide. Upper decoration thread hooking assisting means for pushing down the upper decoration thread portion downward is provided so that the upper decoration thread portion is hooked on the thread hook portion of the upper decoration thread looper. ).

  In order to achieve the same object as described above, the sewing machine with an upper decoration mechanism according to the second aspect of the present invention is provided with a plurality of needles provided so as to be reciprocated up and down in parallel in a direction crossing the cloth feeding direction. And a presser foot, an upper thread guide that is fixedly supported by the sewing machine arm and guides the upper decorative thread from above to a stitch formation area under the presser foot, and the upper decorative thread guide and the presser foot A direction in which the plurality of needles are arranged in parallel to have a thread hook portion for hooking the upper ornament thread portion located between the two pieces of gold and to feed out the upper ornament thread hooked on the yarn hook portion in a direction crossing the cloth feed direction. In the state where the needle thread looper provided so as to be able to move forward and backward is freely movable, the needle reaches or near the top dead center at the end of sewing, and the needle thread looper is moved to the forward end. A tension is provided between the yarn hooking portion of the upper decorative yarn looper and the upper decorative yarn guide. With an upper decoration mechanism provided with an upper decoration thread cutting device that hooks the passed upper decoration thread portion, draws it obliquely rearward and upward and cuts it, and holds the thread end of the cut upper decoration thread In the sewing machine, when the upper decorative yarn looper moves backward from the advanced end position and reaches the retracted end when sewing starts, the upper decorative yarn looper is disposed near the tip of the upper decorative yarn looper. And a hook portion for hooking an upper decorative yarn portion spanned between the upper decorative yarn guide and the upper decorative yarn guide. Upper decoration thread pressing means for pushing down the upper decoration thread portion spanned between the decoration thread cutting device and the upper decoration thread guide downward and assisting the hook portion of the upper decoration thread portion to be hooked. (Claim 2) .

  According to the first and second inventions having the characteristics as described above, the upper decorative yarn portion extends between the yarn hooking portion of the upper decorative yarn looper moving to the advanced end and the upper decorative yarn cutting device. When the sewing operation of the first stitch on the next cloth is started under the sewing end condition that is being held and the upper decoration thread looper moves backward from the advanced end position and reaches the retracted end position, The upper yarn thread portion is pushed downward by the yarn hooking assisting means or the upper ornament thread pushing-down means so that it can be securely and stably hooked to the yarn hooking portion or hook portion of the upper ornament looper. When the decorative yarn looper reaches the advanced end next time, the right end needle is bent at the upper decorative yarn portion located between the yarn hooking portion or the hook portion and the upper decorative yarn cutting device. A bent portion is formed to form the bent yarn portion. It can be positioned in front of the cutting edge of the needle thread. Therefore, even if the end of the needle thread cut at the bottom of the presser foot at the end of sewing, or the needle thread that has been cut off the side of the needle after cutting is in a free state, it is also highly stretchable. Even if the needle thread end after cutting becomes very short due to the use of the needle thread, when the needle moves down, the right end needle and the needle thread ensure that the bent thread part of the upper thread is placed under the presser foot. It can be pushed down, and a predetermined stitch in which the upper decorative thread, the needle thread and the lower looper thread are entangled with each other can be reliably formed from the operation of the first stitch. In addition, since the upper decoration thread can be pushed down below the presser foot by the first stitch in this way, a predetermined stitch can be surely formed in the second stitch and thereafter, and therefore, sewing is not possible. There is an effect that generation of non-defective products can be eliminated.

In particular, as in the second aspect of the invention, a hook portion is provided near the tip of the upper ornament looper so as to face the yarn hook portion, and the upper ornament yarn is pushed down to assist the hook portion in the hook portion. As a means, a plurality of needles are attached to a needle stopper for attaching to the lower end of the needle bar, and are extended downward from an upper decoration thread path that reciprocates up and down, and the upper decoration thread path moves downward. When reaching the end, a thread pressing piece formed so as to be able to push down the upper decorative thread portion by inserting and moving in the thread guide slot of the upper decorative thread guide from above to below (Claim 3). and, wherein the plurality of needles are attached so as to protrude downward on the needle stop side for attachment to the lower end of the needle bar, when the needle stop has reached the moving end downward, the top covering A needle push-down member that abuts against the thread part and pushes down the thread part (Claim 4). When using the one configured to push down the upper decorative yarn portion in synchronization with the downward movement, a special drive mechanism for moving the upper decorative yarn pushing means up and down is unnecessary, and the whole structure In addition to being able to be configured simply and inexpensively, the operation timing with the needle and the upper thread looper can be appropriately set and maintained, and the intended purpose can be reliably achieved even during long-term use.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall perspective view of a three-needle vertical cylinder flat stitch sewing machine which is an example of a sewing machine with an upholstery mechanism according to the present invention, FIG. 2 is an enlarged perspective view of the main part thereof, FIG. It is an expansion perspective view which shows arrangement | positioning relationship. In the following description, the same members as those described in FIGS. 7A to 7D and FIGS. 9A to 9C will be described using the same reference numerals.

  1 to 3, reference numerals 5L, 5M, and 5R are three needles, which are attached to the lower end portion of a needle bar 10 that reciprocates up and down in conjunction with a sewing machine main shaft (not shown) provided in the sewing machine arm 9. It is attached in parallel in the direction crossing the cloth feed direction X via the stopper 7, and supplies needle threads 6L, 6M, 6R, respectively. Reference numeral 11 denotes a cylindrical cylinder bed portion. A needle plate 12 is fixed to the upper surface of the cylindrical cylinder bed portion, and parts and mechanisms for forming stitches such as a lower looper thread looper (see FIG. 9) and cloth feed teeth (inside) Since these are well-known, their description is omitted). Reference numeral 13 denotes a cloth presser which is configured to be switchable between a lowered position where the sewing cloth is pressed against the needle plate 12 from above via a presser bar 14 and a raised position where the cloth is released, and the three needles 5L, A through hole 13a is formed including a needle drop portion through which 5M and 5R are inserted, and a thread passage portion through which the needle threads 6L, 6M and 6R and the upper thread 3 pass.

  Reference numeral 2 denotes an upper decorative thread guide fixedly supported by the sewing machine arm 9 and extending downward. As clearly shown in FIG. 3, the upper decorative thread 3 is inserted into the lower end of the upper decorative thread 3 so as to be movable in the front-rear direction. A thread guide long hole 2a is formed for engaging and guiding the feeding thereof. Reference numeral 8 denotes an upper decoration thread path, which has a thread hole 8a through which the upper decoration thread 3 is inserted near the lower end thereof, and is reciprocated up and down in synchronization with the needles 5L, 5M, 5R attached to the needle stopper 7 Is configured to move.

  A thread push-down piece 8b that can be inserted and moved downward from above in the thread guide slot 2a of the upper decoration thread guide 2 is integrally extended downward at the lower end of the upper decoration thread path 8. When the upper decoration thread path 8 reaches the downward movement end in synchronization with the downward movement of the needles 5L, 5M, 5R, the thread pressing piece 8b is a long hole for thread guide of the upper decoration thread guide 2. The upper decorative yarn 3 is inserted through the yarn hole 8a and passed between the upper decorative yarn guide 2 and an upper decorative yarn cutting device 4 to be described later by inserting and moving in the lower portion 2a. Upper decoration thread pressing means for pressing the portion downward is configured. The thread guide elongated hole 2a of the upper decorative thread guide 2 is enlarged so that the thread pressing piece 8b can be vertically inserted and moved.

  Reference numeral 1 denotes an upper decorative yarn looper, the base end portion of which is fixed to a holder 16 fixed to the vertical axis 15, and the lower portion thereof is bent substantially along a horizontal plane so that the three needles 5L, 5M, 5R The front is curved in an arc shape, and the advancement / retraction drive movement is freely possible along the arc-shaped path in front of the three needles 5L, 5M, 5R in conjunction with the vertical reciprocation of the needle bar 10 It is configured. As clearly shown in FIG. 3, an upper surface side near the tip of the upper decorative thread looper 1 is provided between the upper decorative thread guide 2 and the stitch forming area under the presser foot 13 during a normal sewing operation. A yarn hooking portion 1a is formed which hooks the upper decorative yarn 3 portion which is diagonally positioned over and extends to the left position of the left end needle 5L among the three needles 5L, 5M and 5R.

  On the upper surface of the upper decorative yarn looper 1, the upper decorative yarn looper 1 moves backward from the advanced end position in the front end portion side of the yarn hooking portion 1a, and in the vicinity of the retracted end. The hook portion 18 is provided for hooking the upper decorative yarn 3 portion that is stretched between the upper decorative yarn guide 2 and the upper decorative yarn cutting device 4. The hook portion 18 includes an upright portion 18a rising from the top end of the upper decorative yarn looper 1, an intermediate portion 18b extending parallel to the upper surface of the upper decorative yarn looper 1, and an upright portion 18c extending downward. Between the lower end portion and the upper surface of the upper decorative yarn looper 1, a yarn inlet / outlet portion 18d is formed to open facing the yarn hooking portion 1a.

  Further, the upper decorative thread cutting device 4 is provided between the thread hooking portion 1a of the upper decorative thread looper 1 and the thread guiding elongated hole 2a of the upper decorative thread guide 2 which have moved to the advanced end at the end of sewing. The upper decorative yarn 3 part is composed of a movable knife 4a and a fixed knife 4b which rush and move to the upper decorative yarn 3 part stretched over and hooks the upper decorative thread 3 part and draws it obliquely rearward and upward. Is cut by both the scalpels 4a and 4b, and the thread end of the cut upper decoration thread 3 is clamped and held by the thread end holding spring 4c and the thread holding auxiliary spring 4d.

Next, the upper decorative stitching operation by the three-needle vertical cylinder flat stitch sewing machine configured as described above will be described with reference to FIG.
FIG. 4 (A) shows a state at the end of sewing after the sewing work for the previous cloth has been completed, and is exactly the same as the state shown in FIG. 7 (A). The upper decorative yarn 3 portion is stretched between the decorative yarn guide 2 and the yarn guide long hole 2a, and the needle yarns 6L, 6M, which have been cut or have been cut to the side after cutting are provided. The ends 6l, 6m, 6r of 6R are located in a free state behind the upper decorative yarn 3 portion.

  When the sewing machine is operated in this state and sewing on the next cloth is started, as shown in FIG. 4 (B), the upper thread looper 1 moves back and forth from its advanced end position, and the needles 5L, When 5M, 5R and the upper decoration thread path 8 are moved downward in synchronization and reach the moving end, the thread pressing piece 8b passes through the thread guide long hole 2a of the upper decoration thread guide 2 from above to below. As a result, the upper decorative yarn 3 portion inserted through the yarn hole 8a and spanned between the upper decorative yarn guide 2 and the upper decorative yarn cutting device 4 is pushed downward. .

  Subsequently, as shown in FIG. 4C, after the upper thread looper 1 reaches its retracted end, the needle 5L, 5M, 5R starts moving forward in the parallel direction, and the needle 5L, 5M, 5R and the upper decorative yarn path 8 start to move upward after reaching the bottom dead center. At this time, that is, when the upper decorative yarn looper 1 reaches the retracted end, it moves downward. The portion of the upper decorative yarn 3 in the pressed down state enters the hook portion 18 at the tip of the upper decorative yarn looper 1 and is hooked on the hook portion 18 and is sequentially pulled out as the upper decorative yarn looper 1 moves forward.

  Then, in the state where the upper decorative yarn looper 1 reaches the advanced end next, as shown in FIG. 4 (D), the upper decorative yarn 3 drawn by being hooked on the hook portion 18 is connected to the hook portion 18. The upper decorative thread 3 located between the upper decorative thread cutting device 4 is bent from the front end to the rear end of the right end needle 5R to form a bent portion 3a centered on the right end needle 5R. The upper decorative yarn portion 3b between the bent portion 3a and the hook portion 18 is located in front of the rightmost needle yarn 6R. FIG. 5 shows an enlarged view of FIG. 4D in order to make the state of FIG. 4D easier to understand.

  In this state, the needles 5L, 5M, and 5R are once moved downward, and the ends 6l, 6m, and 6r of the needle threads 6L, 6M, and 6R are connected to the cloth 20 (see FIG. 9) below the cloth presser foot 13 and held. Then, when the needles 5L, 5M, and 5R are moved downward, the bent yarn portion 3a of the upper decorative thread 3 is moved by the right needle 5R and the needle thread 6R as the needles 5L, 5M, and 5R are moved downward. As shown in (E), it is surely pushed down to the stitch formation area under the presser foot 13, and from the operation of the first stitch, the upper decoration thread 3, each needle thread 6L, 6M, 6R and the lower looper A predetermined stitch in which the yarns are entangled with each other is surely formed.

When a predetermined stitch is formed by the sewing operation of the first stitch as described above, the upper decoration thread 3 is used for thread guidance of the stitch formation area under the presser foot 13 and the upper decoration thread guide 2 thereafter. Since it is in a state of being slanted to the right and upward between the elongated holes 2a, the thread hooking of the looper 1 is performed as the upper thread looper 1 advances in the sewing operation after the second stitch. The part 1a repeats the action of hooking the upper decoration thread 3 and pulling it to the left, so that a predetermined stitch is reliably and smoothly formed.
Although not shown, the upper decorative yarn 3 portion hooked on the hook portion 18 during the movement of the upper decorative yarn looper 1 from FIG. 4 (D) to FIG. 4 (E) is the hook portion 18. Is naturally released from the yarn inlet / outlet portion 18d.

  Therefore, the ends of the needle threads 6L, 6M, 6R that are cut at the bottom of the presser foot 13 at the end of the sewing, or are fed to the upper side of the needles 5L, 5M, 5R after cutting are free. Even if the needle thread ends 6l, 6m, 6r after cutting become very short due to the use of the needle threads 6L, 6M, 6R rich in elasticity, During the stitching operation of the stitches, the hook portion 18 attached to the tip of the upper ornament looper 1 is securely hooked to form the bent portion 3a as described above, and the bent portion 3a and the hook are hooked. Since the upper decorative yarn portion 3b between the upper portion and the portion 18 is positioned in front of the rightmost needle yarn 6R, the upper decorative yarn 3 can be surely pushed down to the seam forming area under the presser foot 13, so that the first From the operation of stitches, decorative thread 3, needle threads 6L, 6M, 6 And a predetermined stitch in which the lower looper thread is entangled with each other, and of course, the predetermined stitch can be surely formed even after the second stitch. Generation of non-defective products can be eliminated.

  In the above-described embodiment, the upper decorative yarn 3 inserted through the thread hole 8a of the upper decorative yarn path 8 and spanned between the upper decorative yarn guide 2 and the upper decorative yarn cutting device 4 is used. The upper guide yarn guide 2 has a yarn guide slot 2 at the lower end of the upper ornament thread path 8 as an upper ornament yarn push-down means for pushing down the portion downward and assisting the hook portion 18 to catch the upper ornament yarn 3. The thread pressing piece 8b, which can be inserted and moved from the upper side to the lower side in the upper part 2a, is integrally extended. Instead, as shown in FIG. Alternatively, a substantially L-shaped thread pressing member 21 that protrudes in a protruding manner may be provided.

  When the thread pressing member 21 as shown in FIG. 6 is employed, when the needles 5L, 5M, 5R and the needle stopper 7 reach near the lower moving end, the upper decoration thread guide 2 and the upper decoration thread are used. Of the upper decorative yarn 3 that is stretched between the cutting device 4 and the upper decorative yarn 3, the thread pressing member 21 is brought into contact with a thread portion close to the upper decorative yarn cutting device 4 so that the upper decorative yarn 3 is applied to the hook portion 18. As in the case of the above-described embodiment, a predetermined stitch can be reliably formed from the sewing operation of the first stitch.

  In each of the above embodiments, the hook portion 18 is provided at the tip of the upper thread looper 1 so as to face the original thread hook 1a, and the upper thread is applied to the hook section 18 during the sewing operation of the first stitch. In the above description, the thread pressing piece 8b and the thread pressing member 21 are provided in order to assist the hooking of the hook 3, but instead of this configuration, the hook portion is not provided at the tip of the upper thread looper 1. While only the original thread hooking portion 1a is provided, the needles 5L, 5M, 5R and the needle bar 10 are moved up and down separately to move the upper decoration thread guide 2 and the upper decoration thread cutting device 4 together. Upper decoration thread hooking auxiliary means that can be pushed down so that the upper decoration thread 3 that is stretched between them can be hooked on the thread hooking portion 1a of the upper decoration looper 1 may be provided separately.

  Further, as the upper decoration thread hooking assisting means, the upper decoration thread cutting device 4 itself shown in the above embodiment is moved downward, so that the upper decoration thread 3 is moved to the thread hooking portion 1a of the upper decoration thread looper 1. It is also possible to be able to push down downward so that it can be hooked on. That is, the upper decoration thread cutting device 4 may be configured to be movable up and down so as to be used also as the upper decoration thread hooking assisting means.

  However, in the case where such a separate upper decoration thread hooking auxiliary means is provided, or when the upper decoration thread cutting device 4 also serves as the upper decoration thread hooking auxiliary means, for example, the upper decoration thread pushing means such as an air cylinder or the upper A special drive mechanism for moving the decoration thread cutting device 4 up and down is required, and the operation timing with the needles 5L, 5M, 5R, the upper decoration thread looper 1 and the like is set appropriately, and the setting timing thereof. Therefore, it is necessary to regularly adjust and maintain the system so that it does not go wrong. In that sense, it is desirable from the viewpoint of maintenance in terms of structure, cost, and maintenance to employ the configuration shown in the above embodiments.

  Furthermore, in the above-described embodiment, the present invention is applied to a three-needle vertical cylinder flat stitch sewing machine, but the present invention is not limited thereto, and can be applied to, for example, a flat bed type flat stitch sewing machine, a cylinder bed type flat stitch sewing machine, or the like. .

1 is an overall perspective view of a three-needle vertical cylinder flat stitch sewing machine that is an example of a sewing machine with an upper decoration mechanism according to the present invention. It is an expansion perspective view of the principal part of a sewing machine same as the above. It is an expansion perspective view which shows the structure of the principal part of a sewing machine same as the above, operation | movement, and arrangement | positioning relationship. (A)-(E) is explanatory drawing of the principal part of the top stitch sewing operation | movement of the 1st needle | hook. FIG. 5 is an enlarged view of the state of FIG. It is an enlarged view of the principal part which shows other embodiment. (A)-(D) is explanatory drawing of the principal part of the top stitch sewing operation | movement of the 1st needle | hook by the conventional sewing machine with a top ornament mechanism. FIG. 8 is an enlarged view of the state of FIG. (A)-(C) are explanatory drawings of the positional relationship of a top decoration thread and a needle thread.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper decoration thread looper 1a Yarn hook part 2 Upper decoration thread guide 2a Yarn guide slot 3 Upper decoration thread 4 Upper decoration thread cutting device 5L, 5M, 5R Needle 6L, 6M, 6R Needle thread 6l, 6m, 6r Needle thread End 7 Needle stopper 8 Upper decorative yarn path 8b Thread press piece 9 Sewing arm 13 Work clamp 18 Hook 21 Thread press member

Claims (4)

A plurality of needles arranged in parallel in the direction crossing the cloth feed direction and freely movable up and down, a presser foot, and a sewing machine arm fixedly supported by the upper arm thread from above to sew under the presser foot. An upper thread guide for guiding to the eye forming area, and a thread hook portion for hooking the upper thread portion located between the upper thread guide and the cloth presser. An upper thread looper provided so as to be able to advance and retreat in a parallel direction of the plurality of needles so as to feed the hung upper decorative thread in a direction crossing the cloth feed direction, and the needle is at the top dead center or at the end of sewing. An upper decoration stretched between the yarn hooking portion of the upper decoration thread looper and the upper decoration thread guide in a state of reaching the vicinity and moving the upper decoration thread looper to the advanced end. Hook the thread part and pull it diagonally backward upward to cut it, and the cut In the top covering mechanism with a sewing machine and a, a cover thread cutting device on which holds the yarn end of the upper fancy yarn,
When the upper looper looper moves backward from the advanced end position and reaches the retracted end with the start of sewing, the upper decorative thread looper spans between the upper decorative thread cutting device and the upper decorative thread guide. Upper decoration thread hooking auxiliary means for pushing the upper decoration thread part downward is provided so that the upper decoration thread part is hooked on the thread hook part of the upper decoration thread looper. Sewing machine with decoration mechanism. A plurality of needles arranged in parallel in the direction crossing the cloth feed direction and freely movable up and down, a presser foot, and a sewing machine arm fixedly supported by the upper arm thread from above to sew under the presser foot. An upper thread guide for guiding to the eye forming area, and a thread hook portion for hooking the upper thread portion located between the upper thread guide and the cloth presser. An upper thread looper provided so as to be able to advance and retreat in a parallel direction of the plurality of needles so as to feed the hung upper decoration thread in a direction crossing the cloth feeding direction, and at the end of sewing, An upper decoration stretched between the yarn hooking portion of the upper decoration thread looper and the upper decoration thread guide in a state where the upper decoration thread looper has reached the vicinity thereof and has moved to the advanced end. Hook the thread part, pull it diagonally backward and upward, and cut it. A cover thread cutting device on which holds the yarn end of the cover thread above was, in the top covering mechanism with a sewing machine and a,
Near the tip of the upper decorative thread looper, when the upper decorative thread looper moves backward from the advanced end position and reaches the retracted end when sewing starts, the upper decorative thread looper and the upper decorative thread cutting device A hook portion for hooking the upper decorative yarn portion spanned between the decorative yarn guide is provided opposite to the yarn hook portion, and the upper portion is synchronized with the downward movement of the needle. Upper decorative yarn pressing means for pressing down the upper decorative yarn portion spanned between the decorative yarn cutting device and the upper decorative yarn guide to catch the hook portion of the upper decorative yarn portion on the hook portion. A sewing machine with a top decoration mechanism, characterized in that The upper cover thread depressing means, the upper cover thread path that reciprocates so as to extend downward vertically the plurality of needles mounted on the needle clamp of order attached to the lower end portion of the needle bar, the top covering When the yarn path reaches the downward moving end, the yarn is formed so as to be able to push down the upper decorative yarn portion by inserting and moving from the upper portion to the lower portion of the upper guide yarn guide. The sewing machine with an upholstery mechanism according to claim 2, wherein the sewing machine is constituted by a pressing piece. The upper cover thread depressing means, said plurality of needles are attached so as to protrude downward on the needle stop side for attachment to the lower end of the needle bar, reach the moving end of said needle stop is downward The sewing machine with an upper decoration mechanism according to claim 2, wherein the sewing machine includes a thread pressing member that abuts against the upper decoration thread portion and presses down the yarn portion.

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