EP1113100B1 - Needle thread guide device for double chain stitch sewing machine - Google Patents

Needle thread guide device for double chain stitch sewing machine Download PDF

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Publication number
EP1113100B1
EP1113100B1 EP20000127921 EP00127921A EP1113100B1 EP 1113100 B1 EP1113100 B1 EP 1113100B1 EP 20000127921 EP20000127921 EP 20000127921 EP 00127921 A EP00127921 A EP 00127921A EP 1113100 B1 EP1113100 B1 EP 1113100B1
Authority
EP
European Patent Office
Prior art keywords
needle thread
needle
needles
thread
movable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP20000127921
Other languages
German (de)
English (en)
French (fr)
Other versions
EP1113100A3 (en
EP1113100A2 (en
Inventor
Katsuhiko Yamato Sewing Machine Seizo Co. Iwai
Takashi Yamato Sewing Machine Seizo Co. Mizusaki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yamato Sewing Machine Mfg Co Ltd
Original Assignee
Yamato Sewing Machine Mfg Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Yamato Sewing Machine Mfg Co Ltd filed Critical Yamato Sewing Machine Mfg Co Ltd
Publication of EP1113100A2 publication Critical patent/EP1113100A2/en
Publication of EP1113100A3 publication Critical patent/EP1113100A3/en
Application granted granted Critical
Publication of EP1113100B1 publication Critical patent/EP1113100B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B51/00—Applications of needle-thread guards; Thread-break detectors

Definitions

  • the present invention generally relates to a needle thread guide device for double chain stitch sewing machine and, in particular, to a needle thread guide device for double chain stitch sewing machine in which a double chain stitch is formed by allowing a looper to successively enter a plurality of needle thread loops when two or more needles aligned in a direction orthogonal to a sewing direction move upward from a bottom dead point of their vertically reciprocal path, while forming a needle thread loop on a lower part of a fabric.
  • Fig. 7 shows an important part of one which has two needles.
  • This needle thread guide device comprises a movable needle thread take-up 3 and a needle thread guide 8 fixedly secured to an arm part (not shown) in the vicinity of the leading end of the movable needle thread take-up 3.
  • the needle thread take-up 3 rocks vertically reciprocally as indicated by the arrow u-d, in synchronism with the vertically reciprocal motion of right and left needles 1R and 1L, in order to control feed of right and left needle threads 6R, 6L which are supplied to the right and left needles 1R, 1L, via thread tension devices 4R, 4L, a needle thread eyelet 5 and a needle thread take-up guide 7.
  • These needles 1R and 1L are supported via a needle bar 2 aligned in a direction orthogonal to the sewing direction Y, so as to be reciprocally movable in the vertical direction Z.
  • the needle thread guide 8 receives and supports from the underside a needle thread portion between a first needle thread through-hole 3a formed at the leading end of the movable needle take-up 3, and a second needle thread through-hole 3b located toward the side of a rocking basal end, as shown in Fig. 8.
  • a needle thread take-up guard 9 is formed at the front of the needle thread guide 8.
  • the needle thread guide 8 is, as shown in Figs. 7 and 8, made up of a mounting plate 8a vertically adjustably attached via a slot 11 and a screw 12 to the needle thread take-up guide 7 fixed to an arm part (which is the same as that designated by reference 21 in Fig. 1), and a bar-like thread receiving surface 8b to receive and support the right and left needle threads 6R and 6L on a single plane.
  • the looper 10 is disposed in a bed part (which is the same as that designated by reference 23 in Fig. 1).
  • Figs. 9A, 10A, 11A are diagrams illustrating a positional relation between the leading end of the movable needle thread take-up 3 and the needle thread guide 8.
  • Figs. 9B, 10B and 11B are diagrams illustrating a state that the needle thread guide 8 receives a needle thread.
  • Figs. 9C, 10C and 11C are diagrams in which the right and left needles 1R and 1L are slightly drifted for convenience in illustrating a state of a needle thread loop.
  • Figs. 10D and 11D are diagrams when the right and left needles 1R and 1L are viewed from the sewing direction.
  • the leading end of the looper 10 enters the left needle thread loop 6Lr and the looper thread 10N catches both needle threads 6R and 6L.
  • the right and left needle threads 6R and 6L depart from the thread receiving surface 8b of the needle thread guide 8 and move upward in a straight line. Then, a known sewing operation such as feed of the fabric, descent of both needles 1R and 1L, return of the looper 10 are performed to form a predetermined double chain stitch.
  • the looper 10 In the conventional needle thread guide device for double chain stitch sewing machine with a plurality of needles which has such construction and operation as described above, there is a difference in timing that the looper 10 enters the needle thread loops 6Rr and 6Lr. Specifically, in the case of the two-needle double chain stitch sewing machine as described, the looper 10 first enters and passes through the right needle thread loop 6Rr and then enters the left needle thread loop 6Lr. That is, due to a time deviation in the timing of entering the needle thread loops, the left needle thread loop 6Lr is greater than the right needle thread loop 6Rr by the amount of the time deviation.
  • the greater needle thread loop 6Lr falls down in the direction indicated by the arrow c in Fig. 11C, or hangdowns by its own weight.
  • the leading end of the looper 10 might fail to enter the left needle thread loop 6Lr and the looper needle 10N catches the needle threads 6R and 6L incompletely and unreliably. This results in skip-stitch and fails to form a predetermined double chain stitch.
  • JP-A-07-096088 a double chain stitch sewing machine is disclosed in JP-A-07-096088.
  • the aim of the sewing machine disclosed therein is to have, when sewing a flexible fabri: the degree of strain of a needle thread follow the flexibility of the fabric and to form seams having feeling and soft-swelling, which is also called "balloon stitch".
  • the below object of the present invention is not addressed in this prior art document.
  • a needle thread guide device for double ring stitch sewing machine comprising: (i) plural needles movable vertically reciprocally aligned in a direction orthogonal to a sewing direction; a looper moving forward from one side to the other of the aligned plural needles so as to successively enter plural needle thread loops when the plural needles move upward from a bottom dead point while forming a needle thread loop; (ii) a movable needle thread take-up rocking vertically reciprocally as the needles move vertically reciprocally, thereby to control feed of a needle thread supplied to the needles via a thread tension device and a needle thread eyelet, the movable needle thread take-up being disposed outside of an arm part; and (iii) a needle thread guide fixed to the arm part in the vicinity of the leading end of the movable needle thread take-up, the needle thread guide receiving and supporting, from its underside, needle thread portions between first and second needle thread through-holes when the needles are located at the bottom dead point and the
  • the cam for applying a tensile force to a needle thread may be separated from the needle thread guide.
  • the cam is folded so as to be integral with the thread receiving surface of the needle thread guide. Thereby, the parts are unified so that attachment to the arm part is facilitated and also the timing of applying a tensile force is optimized.
  • the cam may be constructed so that it can adjust a tensile force applied to a needle thread.
  • the tensile force can be adjusted appropriately and a predetermined function can be performed reliably irrespective of the kind of the needle thread.
  • the cam may be configured so that it can continuously apply a tensile force to tighten the needle thread even after the looper enters the needle thread loop. This enables to tighten the needle thread by tensing the needle thread after the looper thread catches the needle loop, thereby forming a stitch in accordance with stretch of the fabric.
  • the timing of applying a tensile force to a needle thread supplied to the needle that the looper enters finally may be immediately before the looper enters the corresponding needle thread loop, that is, the time between the point the needle starts moving upward from the bottom dead point and the point the leading end of the looper enters the corresponding needle thread loop. In the present specification, this period of time is referred to as "immediately before the looper enters.”
  • Fig. 1 is a front view, partially broken away, disclosing a two-needle double chain stitch sewing machine to which the present invention is applied.
  • Fig. 2 is an enlarged front view of an important part of Fig. 1.
  • a needle bar 2 is supported so as to be movable vertically reciprocally via upper and lower bearings (not shown).
  • a fabric pressing mechanism Disposed near the needle bar 2 is a fabric pressing mechanism, which is well known and a description thereof is thus omitted.
  • Two needles i.e., right and left needles 1R and 1L, are attached via a pointer stop 22 to the lower end of the needle bar 2.
  • a bed part 23 extends from a lower part of the basal end of the arm part 21 to the left in parallel relation to the arm part 21.
  • the leading end of the bed part 23 contains components for sewing operation such as a throat plate, pressing mechanism, looper 10 and feed mechanism, which are well known and a description thereof is thus omitted.
  • a double chain stitch sewing machine frame 24 is made up of the bed part 23 and arm part 21.
  • the frame 24 is basically provided with components similar to those in the conventional two-needle double chain stitch sewing machine as described with respect to Figs. 7 and 8.
  • Representative components are thread tension devices 4R, 4L and 4A; a needle thread eyelet 5; a needle thread take-up guide 7; a needle thread take-up 3 that rocks vertically reciprocally in synchronism with the vertical reciprocation of the right and left needles 1R and 1L, in order to control feed of right and left needle threads 6R and 6L; and a needle thread guide 8 that receives and supports, from the underside, a needle thread portion between a first needle through-hole 3a formed on the side of the leading end and a second needle thread through-hole 3b formed toward the side of a rocking basal end in the movable needle thread take-up 3.
  • the construction and function of these components are identical with that shown in Fig. 8, and the same reference numerals are used for similar parts and a description thereof is thus
  • a needle thread oiling device 14 is provided on the needle thread eyelet 5.
  • the oiling device 14 applies a lubricating oil to the right and left needle threads 6R and 6L passing through the needle thread eyelet 5, thereby preventing occurrence of trouble such as broken thread and skip-stitch when using a synthetic fiber thread or fabric.
  • the movable needle thread take-up 3 is constructed so that it relatively moves to a driving main shaft (not shown) and is vertically reciprocally rockable via a needle thread feed bracket 16, by reciprocal rotation of a needle thread feed shaft 15 exposed from the outside part of the arm part 21 in the frame 24.
  • the needle thread guide 8 of the needle thread guide device in the two-needle double chain stitch sewing machine is, as shown in Figs. 2 and 3, made up of a mounting plate 8a attached vertically adjustably via a slot 11 and a screw 12 to the needle thread take-up guide 7 fixed to the arm part 21, and a bar-like thread receiving surface 8b to receive and support the right and left needle threads 6R and 6L on a single plane.
  • the looper 10 approaches the right and left needle threads 6R and 6L in the order named, which are received and supported on the thread receiving surface 8b, as the movable needle thread take-up 3 rocks upward.
  • a cam 8c is integrally formed by folding the mounting plate 8a. The cam 8c can apply a tensile force to the left needle thread 6L immediately before the looper 10 enters a needle thread loop 6Lr.
  • FIGs. 4A, 4B, ... 6D are diagrams illustrating a positional relation between the leading end of the movable needle thread take-up 3 and the needle thread guide 8.
  • Figs. 4B, 5B and 6B are diagrams illustrating a state that the needle thread guide 8 receives a needle thread.
  • FIGS. 4C, 5C and 6C are diagrams in which the right and left needles 1R and 1L are slightly drifted for convenience in illustrating a state of a needle thread loop.
  • Figs. 5D and 6D are diagrams when the right and left needles 1R and 1L are viewed from the sewing direction.
  • the leading end of the looper 10 enters the left needle thread loop 6Lr.
  • the left needle thread 6L contacts a top projected surface 8c2 of the cam 8c and is tensioned so that the left needle thread loop 6Lr is maintained in a constant size.
  • the looper 10 reliably enters, from its leading end, the left needle thread loop 6Lr. Therefore, the looper thread 10N reliably catches the right and left needle threads 6R and 6L, thereafter, the known sewing operation such as feed of a fabric, decent of both needles 1R and 1L and return of the looper 10 are performed to form a predetermined double chain stitch.
  • the left needle thread 6L can move along the top projected surface 8c2 which is vertically linear, and therefore, even after the looper 10 enters the left needle thread loop 6Lr, a tensile force is continuously applied to the left needle thread 6L for tightening the stitch. Even for a stretch fabric, a predetermined double chain stitch can be reliably formed while following up the stretch of the fabric.
  • the movable needle thread take-up 3 When, as the needles 1R and 1L move upward, the movable needle thread take-up 3 reaches its top dead point of rock and then starts to rock downward, the left needle thread 6L moves downward to the top projected surface 8c2 while being rubbed with an upper slope 8c3 of the cam 8c. Thereby, a tensile force is applied to the left needle thread 6L hung on the middle of the looper 10, so that a triangle of the back of a stitch is stabilized to prevent skip-stitch.
  • the cam 8c may be separated from the needle thread guide 8.
  • the cam 8c may be fixed or movable, for example, in x direction in Fig. 4B, so that a tensile force applied to the left needle thread 6L is adjustable. Irrespective of the kind of the needle thread, a predetermined function can be reliably performed by suitably adjusting the tensile force depending on the twisted state and characteristic of the left needle thread 6L.
  • the present invention may be applied to any double chain stitch sewing machines having three or more needles, alternatively, to interlock stitch sewing machines having a plurality of needles for sewing an upper fancy thread into a double ring stitch. In any case, it is able to obtain the same effect as described in the foregoing embodiment.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
EP20000127921 1999-12-30 2000-12-20 Needle thread guide device for double chain stitch sewing machine Expired - Lifetime EP1113100B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP37741199A JP4296560B2 (ja) 1999-12-30 1999-12-30 二重環縫いミシンの針糸案内装置
JP37741199 1999-12-30

Publications (3)

Publication Number Publication Date
EP1113100A2 EP1113100A2 (en) 2001-07-04
EP1113100A3 EP1113100A3 (en) 2002-04-17
EP1113100B1 true EP1113100B1 (en) 2005-09-28

Family

ID=18508768

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20000127921 Expired - Lifetime EP1113100B1 (en) 1999-12-30 2000-12-20 Needle thread guide device for double chain stitch sewing machine

Country Status (5)

Country Link
EP (1) EP1113100B1 (zh)
JP (1) JP4296560B2 (zh)
CN (1) CN1116462C (zh)
DE (1) DE60022852T2 (zh)
TW (1) TWI228161B (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100878862B1 (ko) * 2001-08-02 2009-01-15 페가수스미싱세이죠가부시기가이샤 다수의 바늘을 가진 이중환 재봉 미싱의 침사 제어장치

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003117271A (ja) * 2001-10-17 2003-04-22 Yamato Sewing Mach Co Ltd ミシン
JP3834754B2 (ja) * 2002-05-01 2006-10-18 ヤマトミシン製造株式会社 ミシンの針糸繰り装置
CN100389236C (zh) * 2002-05-10 2008-05-21 大和缝纫机制造株式会社 缝纫机过线装置
JP2008220597A (ja) * 2007-03-12 2008-09-25 Yamato Sewing Mach Co Ltd ミシンの駆動装置
CN102140738A (zh) * 2010-11-12 2011-08-03 苏州市青田企业发展有限公司 双针车压脚定位装置
JP7371915B2 (ja) 2020-03-26 2023-10-31 オルガン針株式会社 偏平縫いミシン用針および偏平縫いミシンを使用した縫製方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1272600B (it) * 1993-09-10 1997-06-26 Rimoldi S R L Ora Rimoldi Necc Dispositivo per formare una catenella continua in macchine per cucire a punto ornamento senza copertura a piu' aghi
JP2974557B2 (ja) * 1993-09-30 1999-11-10 ジューキ株式会社 二重環縫いミシンの縫い目形成方法および装置
JP3489089B2 (ja) * 1995-09-01 2004-01-19 ヤマトミシン製造株式会社 ルーパ糸繰り装置
JP3498480B2 (ja) * 1996-04-11 2004-02-16 ヤマトミシン製造株式会社 糸繰り装置付ミシン
JPH09285666A (ja) * 1996-04-19 1997-11-04 Pegasus Sewing Mach Mfg Co Ltd 二重環縫いミシンの糸制御装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100878862B1 (ko) * 2001-08-02 2009-01-15 페가수스미싱세이죠가부시기가이샤 다수의 바늘을 가진 이중환 재봉 미싱의 침사 제어장치

Also Published As

Publication number Publication date
EP1113100A3 (en) 2002-04-17
EP1113100A2 (en) 2001-07-04
JP2001187290A (ja) 2001-07-10
JP4296560B2 (ja) 2009-07-15
DE60022852D1 (de) 2006-02-09
DE60022852T2 (de) 2006-06-22
TWI228161B (en) 2005-02-21
CN1301890A (zh) 2001-07-04
CN1116462C (zh) 2003-07-30

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