US3720178A - Chainstitch conversion device for lockstitch sewing machines - Google Patents

Chainstitch conversion device for lockstitch sewing machines Download PDF

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Publication number
US3720178A
US3720178A US00201514A US3720178DA US3720178A US 3720178 A US3720178 A US 3720178A US 00201514 A US00201514 A US 00201514A US 3720178D A US3720178D A US 3720178DA US 3720178 A US3720178 A US 3720178A
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United States
Prior art keywords
thread
bobbin
deflecting member
loop
throat plate
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
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US00201514A
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English (en)
Inventor
M Ivanko
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.)
SSMC Inc
Original Assignee
Singer Co
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Filing date
Publication date
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Publication of US3720178A publication Critical patent/US3720178A/en
Assigned to SSMC INC., A CORP. OF DE reassignment SSMC INC., A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SINGER COMPANY, THE
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B1/00—General types of sewing apparatus or machines without mechanism for lateral movement of the needle or the work or both
    • D05B1/08—General types of sewing apparatus or machines without mechanism for lateral movement of the needle or the work or both for making multi-thread seams
    • D05B1/14—Combined or alternative chain-stitch and lock-stitch seams
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B73/00—Casings
    • D05B73/04—Lower casings
    • D05B73/12—Slides; Needle plates

Definitions

  • ABSTRACT [22] Filed: Nov. 23, 1971 A device for converting a lockstitch sewing machine into condition for forming single thread chainstitches
  • Appl' 201514 including a replacement throat plate with a thread engaging pin depending therefrom, and a thread deflect- [52] US. Cl ..112/168, 112/202 ing member adapted to replace the bobbin in the sew- [51] Int. Cl.
  • the thread deflecting member is shiftably supported References Cited in the loop taker and arranged to be influenced only v UNITED S T PATENTS by the sewing thread for movement into and out of a position ma1nta1n1ng the sewrng thread 1n engagement 809,660 1/1906 Ammerman ..112/168 with the thread loop engaging pin.
  • FIG. 1 represents a perspective view of a lockstitch forming loop taker together with fragments of the needle, throat plate, and bobbin thread pulloff element of a sewing machine to which the chainstitch conversion device of this invention has been applied,
  • FIG. 2 is a cross sectional view taken substantially along line 2-2 of FIG. 1 and showing the position of the parts as the thread loop is about to be released afterpenetration thereof by the needle,
  • FIG. 3 is a cross sectional view taken substantially along line 2-2 of FIG. 1 showing the thread loop detained by the chainstitch conversion fittings in readiness for penetration of the loop by the needle,
  • FIG. 4 represents a bottom plan view of the chainstitching throat plate
  • FIG. 5 is a bottom plan view of the thread deflecting member of this invention.
  • FIG. 6 is a side elevational view thereof
  • FIG. 7 is a top plan view thereof.
  • 10 indicates a Iockstitch rotary loop taker formed with a loop. seizing beak 11 and preferably of the type arranged to rotate on a vertical axis substantially parallel to the path of endwise reciprocation of a thread carrying sewing machine needle 12.
  • a bobbin case 13 is maintained stationary within the loop taker 11 by the constraining means (not shown) which may be of any conventional construction.
  • the bobbin case 13 shown in the drawing is of a known type in which a pivoted hold-down arm 14 is carried on the bobbin case and provided with a depending projection 15 adapted to enter a central depression in a bobbin so as to hold in place and frictionally resist turning of a bobbin within the loop taker for the formation of lockstitches (Federal Stitch Type 301
  • the conversion device of this invention for changing a lockstitch sewing machine into a machine capable of forming single thread chainstitches includes a replacement throat plate 20 for chainstitching.
  • the chainstitching throat plate 20 is similar to a throat plate usable for the formation of lockstitches in that it includes apertures 21 to facilitate securing the throat plate in place, slots 22 to accommodate a work feed dog 23, and an overall shape identical with the conventional throat plate.
  • the chainstitching throat plate 20 differs from the throat plate usable for lockstitches in that an aperture 24 through which the needle penetrates is elongated in the direction of the feed dog slots 22.
  • Another difference of the chainstitching throat plate 20 in comparison with a Iockstitch forming throat plate is the provision of a depending thread engaging pin 25 projecting therefrom.
  • the thread engaging pin is formed with a slabbed portion 26 at the free extremity thereof.
  • the chainstitch conversion device of this invention also includes a thread loop deflecting member indicated generally at 30 which is adapted to be substituted in the bobbin case 13 in place of a bobbin which would be required for the formation of lockstitches.
  • the thread loop deflecting member take the form of a disk formed with a central depression 31 adapted to accommodate the projection 15 of the bobbin hold-down arm 14 which thus serves to constrain the thread loop deflecting member in place in the bobbin case.
  • a radial arm 32 is formed on the thread loop deflecting member which fits between the arms of the work feed dog and extends beneath the thread engaging pin 25 on the chainstitching throat plate 20.
  • the arm 32 serves to direct thread loops onto the thread engaging pin 25 and to regulate the release of loops of thread from the thread engaging pin.
  • the radial arm 32 is preferably formed with a shallow recess 33 which provides a seat into which the thread engaging pin 25 is accommodated.
  • the thread loop deflecting member 30 is formed with a depending annular flange 35 which projects within the bobbin case when the thread loop deflecting member is positioned therein and serves to prevent needle thread loops from snagging parts of the bobbin case as the thread loops are being influenced by the thread loop deflecting member.
  • a pair of fulcrum projections 36 which as shown in FIG. 6 are located between the central depression 31 and the radial arm 32 of the thread loop deflecting member.
  • the fulcrum projections define an axis X-X for rocking movement of the thread loop deflecting member 30 relatively to the bobbin case 13, which axis is spaced the distanced indicated at Y in FIG. 6 from the central depression 31 in the direction of the radial arm 32.
  • the hold-down arm 14 will apply downward pressure on the opposite side of the axis X-X on the thread loop deflecting member from the radial arm 32 and will thus bias the radial arm upwardly against the thread engaging pin 25. Any thread loop which is engaged by the loop seizing beak ll of the loop taker will thus be directed by the thread loop deflecting member onto the thread engaging pin 25 as shown in FIG. 3.
  • a thread pull-off member 40 which is conventional in lockstitch sewing machines where it serves to draw off bobbin thread during stitch formation so as to promote uniformity in lockstitch formation.
  • the thread pull-off member may be formed as a lever 41 pivoted as at 42 to the machine frame and provided with a needle accommodating aperture 43.
  • the thread pull-off device may include a return spring 44 which biases a follower projection 45 on the lever against the underside of the feed dog 23 as shown in FIG. 3.
  • the outer rim portion 46 of the needle aperture in the thread pull-off member provides the active pull-off element which influences the sewing threads.
  • the follower projection 45 in contact with the feed dog causes the thread pull-off member also to be lowered and the thread T which has been carried through the needle aperture 43 in the thread pull-off member will be drawn downwardly with it by the outer rim portion 46.
  • This downward pull exerted on the thread loop which is detained on the thread engaging pin 25 will exert a downward force on the radial arm 32 of the thread loop deflecting member 30.
  • the thread loop deflecting member is thus drawn downwardly moving the bottom of the recess 33 away from the thread engaging pin 25, a passageway is provided therebetween through which the thread loop will be released from the thread engaging pin and will be freed therefrom so that it may be drawn first onto the needle and then upwardly into the stitches being formed in work fabrics W the next time the needle is raised.
  • the recess 33 in the radial arm 32 of the thread loop deflector is sufficiently deep that it cannot move completely out of engagement with the thread engaging pin 25. In this way, the pin 25 provides restraint against rotation of the thread loop deflector 30.
  • the release of the thread loops from the thread engaging pin 25 takes place while the feed dog is lowered which corresponds in time to that portion of each stitch forming cycle when the needle occupies the position penetrating the work fabrics W.
  • the thread loops will be released from the thread engaging pin 25, therefore, only after the needle has penetrated the loop and, therefore, a continuing chain of thread loops will be formed.
  • a chainstitch conversion device for a lockstitch sewing machine having a thread carrying needle, a rotary loop taker journaled on an axis perpendicular to and beneath a throat plate which is formed with a needle aperture and feed dog accommodating slots, and a bobbin accommodating case constrained against rotation in said loop taker and provided with a bobbin holddown arm downwardly biased and formed with a projection disposed for engagement with the center of the bobbin in the bobbin case
  • said chainstitch conversion device comprising a chainstitching throat plate adapted to replace the conventional throat plate, said chainstitching throat plate being formed with a depending thread engaging pin located in front of the needle aperture, and a thread loop deflecting member adapted to replace the bobbin in the bobbin case of said loop taker, said thread loop deflecting member comprising a disk formed with a central depression accommodating said bobbin hold-down arm projection, a radial arm projecting from said thread loop deflecting member and underlying said thread engaging pin depending from said chainst
  • a chainstitch conversion device for a lockstitch sewing machine as set forth in claim 1 in which a thread pull-off element is shiftably supported for movement toward and away from the throat plate in a path between the path of said needle and the thread engaging pin depending beneath said chainstitch throat plate, and in which said thread loop deflecting member is maintained in spaced relationship with said thread pulloff element.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US00201514A 1971-11-23 1971-11-23 Chainstitch conversion device for lockstitch sewing machines Expired - Lifetime US3720178A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US20151471A 1971-11-23 1971-11-23

Publications (1)

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Application Number Title Priority Date Filing Date
US00201514A Expired - Lifetime US3720178A (en) 1971-11-23 1971-11-23 Chainstitch conversion device for lockstitch sewing machines

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US (1) US3720178A (enrdf_load_stackoverflow)
JP (1) JPS5332749Y2 (enrdf_load_stackoverflow)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3807330A (en) * 1971-09-25 1974-04-30 Aisin Seiki Sewing machine usable in both lock stitch mode and chain stitch mode
US4266494A (en) * 1977-11-09 1981-05-12 The Singer Company Anti-haloing throat plate
US4278037A (en) * 1979-09-14 1981-07-14 The Singer Company Chain stitch conversion for lock stitch sewing machine
US4297957A (en) * 1978-09-11 1981-11-03 The Singer Company Anti-haloing throat plate
US4316421A (en) * 1978-09-11 1982-02-23 The Singer Company Anti-haloing throat plate
FR2544351A1 (fr) * 1983-04-14 1984-10-19 Singer Co Garniture de point de chainette pour boite a canette
US5887533A (en) * 1995-10-09 1999-03-30 Juki Corporation Chain-stitch sewing machine with knot tying
CN103320970A (zh) * 2013-06-26 2013-09-25 苏州巨康缝制机器人有限公司 一种单向线迹缝纫机

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US809660A (en) * 1904-05-02 1906-01-09 Edwin J Toof Company Interchangeable lock and chain stitch sewing-machine.
US3173391A (en) * 1963-08-07 1965-03-16 Singer Co Chain stitch device for lock stitch sewing machines
US3173390A (en) * 1963-08-07 1965-03-16 Singer Co Chain stitch device for lock stitch sewing machines
US3194197A (en) * 1963-08-07 1965-07-13 Singer Co Chain sitch device for lock stitch sewing machines
US3253560A (en) * 1964-02-24 1966-05-31 Singer Co Chain stitch devices for lock stitch sewing machines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US809660A (en) * 1904-05-02 1906-01-09 Edwin J Toof Company Interchangeable lock and chain stitch sewing-machine.
US3173391A (en) * 1963-08-07 1965-03-16 Singer Co Chain stitch device for lock stitch sewing machines
US3173390A (en) * 1963-08-07 1965-03-16 Singer Co Chain stitch device for lock stitch sewing machines
US3194197A (en) * 1963-08-07 1965-07-13 Singer Co Chain sitch device for lock stitch sewing machines
US3253560A (en) * 1964-02-24 1966-05-31 Singer Co Chain stitch devices for lock stitch sewing machines

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3807330A (en) * 1971-09-25 1974-04-30 Aisin Seiki Sewing machine usable in both lock stitch mode and chain stitch mode
US4266494A (en) * 1977-11-09 1981-05-12 The Singer Company Anti-haloing throat plate
US4297957A (en) * 1978-09-11 1981-11-03 The Singer Company Anti-haloing throat plate
US4316421A (en) * 1978-09-11 1982-02-23 The Singer Company Anti-haloing throat plate
US4278037A (en) * 1979-09-14 1981-07-14 The Singer Company Chain stitch conversion for lock stitch sewing machine
FR2544351A1 (fr) * 1983-04-14 1984-10-19 Singer Co Garniture de point de chainette pour boite a canette
US4487142A (en) * 1983-04-14 1984-12-11 The Singer Company Bobbin case chain stitch insert
US5887533A (en) * 1995-10-09 1999-03-30 Juki Corporation Chain-stitch sewing machine with knot tying
CN103320970A (zh) * 2013-06-26 2013-09-25 苏州巨康缝制机器人有限公司 一种单向线迹缝纫机

Also Published As

Publication number Publication date
JPS5332749Y2 (enrdf_load_stackoverflow) 1978-08-14
JPS4865449U (enrdf_load_stackoverflow) 1973-08-20

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Date Code Title Description
AS Assignment

Owner name: SSMC INC., A CORP. OF DE, CONNECTICUT

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:SINGER COMPANY, THE;REEL/FRAME:005041/0077

Effective date: 19881202