US3882806A - Cover thread pulling and take-up device for multineedle sewing machines - Google Patents

Cover thread pulling and take-up device for multineedle sewing machines Download PDF

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Publication number
US3882806A
US3882806A US405033A US40503373A US3882806A US 3882806 A US3882806 A US 3882806A US 405033 A US405033 A US 405033A US 40503373 A US40503373 A US 40503373A US 3882806 A US3882806 A US 3882806A
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United States
Prior art keywords
thread
cover
drive shaft
stitch
pulling element
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Expired - Lifetime
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US405033A
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English (en)
Inventor
Nerino Marforio
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Virginio Rimoldi and Co SpA
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Virginio Rimoldi and Co SpA
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Application filed by Virginio Rimoldi and Co SpA filed Critical Virginio Rimoldi and Co SpA
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B49/00—Take-up devices, e.g. levers, for the needle thread
    • D05B49/02—Take-up devices, e.g. levers, for the needle thread operated by cams or linkages

Definitions

  • ABSTRACT A multineedle sewing machine having a cover thread pulling device which is linked to a cover stitch device comprising an upper looper.
  • the cover thread pulling device is fixed near the upper looper and moves integrally therewith to exercise a pull of the cover thread without being influenced by the stretching of the thread due to the latters elasticity which is now negligible due to a shortening of the length of the thread exposed to the action of the thread pulling device.
  • the present invention relates to a thread pulling device for a multineedle sewing machine cover thread, the said device being linked to a cover stitch device complete with upper looper, and fitted with a movable thread take-up element functionally connected to the said cover stitch device, the whole so designed as to act directly on the cover thread.
  • Thread pulling devices of this kind are already well known in the art, but the thread take-up element acting directly on the cover thread so as to allow it to run freely to the workpiece during the stitching operation and to pick it up at the end of thereof, has drawbacks exercising a negative influence on the sewing operation.
  • the thread used for cover stitching is very elastic and the excessive length of thread between the two devices is impairing its soundness.
  • the action of the thread pulling devices too results to be somewhat imperfect and not very efficient as regards the perfect and uniform formation of the cover stitches, resulting very often in the wrinkling of the workpiece and stressing at the point of sewing.
  • the thread pulling device of the known kind is subjected to an oscillating motion which, for each stitch, rhythmatically first tightens and then releases the thread, lengthening thus each time the real path to be covered, this to pick up part of the excess of thread inserted into the stitches to be formed, and to recall at the same time from the spool the length of thread which, at the end of the cycle, is absorbed by the stitch.
  • the thread to be able to respond in the best way to the action of the pulling and pick-up device, must first be drawn out so as to take up all of its elasticity, and then moved.
  • the threads natural internal tension is increased until reaching its maximum drawn-out length when the said device will impress on it the required forward motion.
  • the thread must be sufficiently prestretched to maintain it at the required length for being able to respond as soon as possible to the action of the pulling device. It is obvious that the pretensioning of the thread required to keep the latter stretched out to the limit of its resistence and capable of eliminate its natural elasticity, must have a very high value.
  • the technical problem to be resolved mainly consists in reducing the distance between the thread pulling device and the cover stitch device, as well as in changing the laws of motion of the thread pulling device so as to ensure a more suitable and efficient action of the cover thread when forming the single points.
  • the thread pulling device acting on the cover thread has an influence of the quality of the seams.
  • the thread pulling device periodically increases the length of the thread to form a loop permitting at the same time the lengthening of that part of the thread available for the cover stitch device for forming good stitches, but it is also necessary that the thread be handled according to a particular law ensuring that the taking up of the excess thread tightens the stitches without causing wrinkling or an excessive tightening of the finished seam.
  • the thread-pulling element with an attachment for connecting it to the cover stitch device drive shaft and a centre part connected at one side to the said attachment shaped as offset at the other side with the free end opportunely bent back to prevent the thread from sliding off; the said centre section being displaced with respect to the line joining the said attachement to the free end; the displacement being such as to determine the said offset provided as a temporary obstacle against the cover thread prematurely leaving the said centre section which exercises a constant and uniform pull on the said thread; the said free end being designed so as to exercise a final pull on the cover thread to tighten the stitch being formed and recall at the same time from the spool a length of thread which is sufficient to form a new stitch. It is evident that this new characteristic has the advantage of permitting the formation of a perfect and safe tightening of the stitch, which cannot be obtained without the final pull.
  • FIG. 1 is a sectional view of the object of the present invention applied to a sewing machine of the abovementioned type;
  • FIG. 2 is a section along linr II-II of FIG. 1;
  • FIG. 3 is an enlarged plan of the thread-pulling device here referred to;
  • FIGS. 4 and 5 schematically show two different phases of stitching complete with cover stitch.
  • the thread pulling device 10 object of the present invention, is fixed to a multineedle sewing machine and linked to a cover stitch device 11.
  • the said sewing machine comprises a frame provided with an arm 12 over a base (not shown) fitted with the table 13 which receives the workpiece during the sewing operation.
  • a drive shaft 14 is fixed in the manner of a rock shaft inside of the arm 12 and is fitted with a lever arm 15 hinged to a link 16 for transmitting the rocking movements of the said drive shaft to the cover stitch device 11.
  • the said device consists of an oscillatably driven drive shaft 17 provided at the top with an arm 18 connected in turn to the link 16.
  • the other end of the drive shaft 17 projecting from the bottom of the frame carries a clamp 19 of the thread pulling device 10 (FIG. 2) and a support 20 for the upper looper 21 of the cover stitch device.
  • the said upper looper is positioned near the table 13 and is provided for gripping the thread 22 so as to tenter it as required among the threads (not shown) carried by the needles 23 of the sewing machine.
  • the thread pulling device 10 comprises in addition to the said clamp 19 also an opportunely shaped rod which defines a thread-pulling element 24 adjustably fixed to the said clamp 19 and which moves integrally with the upper looper 21.
  • a plate 25 is fixed with screws 26 to lower part of arm 12 of the machine near the cover stitch device and also very near to the support 20 of the upper looper 21.
  • the plate 25 (see also FIG. 3) is provided with two parallel lugs 27 each of which neing provided with a hole 28 through which passes the cover thread 22 leading to the upper looper 21.
  • the thread guide lugs 27 are linked together by a crossbar 29 which acts as spacer and connects them at the same time to plate 25.
  • a crossbar 29 acts as spacer and connects them at the same time to plate 25.
  • the movement of the said thread-pulling element 24 between the said thread guide lugs 27 is provided for generating a loop in the thread and lengthen it for having sufficient thread available at the stitches for ensuring the perfect tightening of the latter and, at the same time, allowing sufficient thread to be taking up at the spool for replacing that used up for making the stitch.
  • the plate 25 is also fitted with a shaped tailpiece 30 carrying a disk tensioning element 31 for passing the cover thread 22 and a pair of thread guides 32 positioned between the said tensioning element and a standard thread spool (not shown).
  • the sewing machine comprises the known presser device of which only the presser bar 33 is shown; a needle clamp 34 is fixed to the lower part of the needle bar 35 which slides vertically in the said arm 12.
  • the upper looper 12 is provided to grip by means of the gripping point 36 the cover thread which normally runs at the right of the needles 23 and shift it to the left thereof and link it to the thread carried by each of them.
  • the thread is guided by the thread guides 37,38,39.
  • the first one is at the top to lead the thread coming from the thread pulling device to the second one at the bottom near the gripping zone.
  • the third one is fixed to the needle clamp 34 and follows the movements of the latter during its vertical displacement during the making of a stitch.
  • the thread-pulling device 24 is so shaped as to possess a centre section 40 linked at one side to an attachment 41 designed to be inserted into the clamp 19, and having at the other side a free end 42 opportunely curved to prevent temporarly the thread to slide off.
  • the centre section 40 is rather displaced relative to the position of the link A joining the attachment 41 to the curved up end 42 to ensure that the said centre section 40 contact the thread 22 stretched out between the two holes 28 before the said end.
  • the above displacement defines a bend 43 in the thread pulling element 24, which, because of the motion the latter carries out together with the clamp 19 around the axis of the drive shaft 17 of the cover stitch device 11, serves as temporary obstacle against the rapid sliding off of the thread 22 from the centre section 40 toward the curved up end 42.
  • the object of the present invention has been linked by way of example without being limited thereto, to a multineedle interlock, double-locked chain stitch sewing machine which, as known, has only one main looper.
  • the cover stitch and the sewing stitch are made simultaneously, because the thread 22 is locked to the needle threads 45 opportunely held back by the main crochet 46 operating beneath the table 13 of the machine.
  • the main looper 46 moves forward to grip in turn all the needle threads 45 carried by the needles 23 all lowered; the upper looper 21 moves from the right to the left relative to the said needles 23 to grip the cover thread 22 having been fed forward by the lower thread guide 38, whilst the intermediate thread guide 39 is near the lower one, perfectly in line with the latter and the upper one 37.
  • the main looper 46 moves back to permit the forming of of a new series of stitches; the needles 23 move downwards carrying with them also the length 22a of the cover thread 22 in the meantime left free by the upper looper 21.
  • the thread-pulling device recovers thread by the action of the thread-pulling element 24, the centre section 40 of which is now almost in contact with the cover thread stretched out between the holes 28, while the curved end 42 is held back near the crossbar 29 in the space formed by the thread guide lugs 27.
  • the centre portion 40 exercises a thrust onto the said thread and, being nearer the drive shaft 17, moves together with the latter but slower than the curved end 42, and exercising a uniform and constant thrust thereon.
  • the thread is forced to follow this movement for a certain time, at the end of which it will overcome the obstacle created by the bend 43 and slide onto the bend end 42 which, being now farther away from the said shaft 17, moves in a faster manner.
  • the thread pulling element 24 being adjustably fixed to the clamp 19, its travel for each cycle can be varied; positioning it nearer or farther away from the drive shaft 17, it is possible to obtain a smaller or greater feed in of thread and a smaller or greater tightening pull at the end.
  • a cover stitch device for sewing machines of the multi-needle type comprising:
  • an oscillatable drive shaft having an upper looper carried on one end of and moveable with said drive shaft;
  • a thread pulling element operatively connected to said drive shaft and movable with said upper looper in a first direction to draw and hold under tension a predetermined amount of cover thread from its source and in a second direction to release the cover thread to the upper looper for its presentation to the stitches being formed by the needles of the sewing machine.
  • said thread pulling element defines a rod member having one end adjustably clamped to said drive shaft, an offset center section for exercising a constant and uniform pull on the cover thread while moving in the first direction with said drive shaft and a curved free end for exerting a sharp final pull on the cover thread for tightening the previously formed stitch and withdrawing a sufficient amount of cover thread for the subsequent stitch.
  • said cover stitch device includes a pair of spaced parallel lugs (27) having aligned holes (28) through which the cover thread extends and between which said off-set center section of said thread pulling element is movable to draw and tension the thread as it moves in its first direction of travel.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US405033A 1972-10-20 1973-10-10 Cover thread pulling and take-up device for multineedle sewing machines Expired - Lifetime US3882806A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT30712/72A IT969729B (it) 1972-10-20 1972-10-20 Dispositivo tirafilo per filo di copertura in macchina per cucire multiaghi

Publications (1)

Publication Number Publication Date
US3882806A true US3882806A (en) 1975-05-13

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Family Applications (1)

Application Number Title Priority Date Filing Date
US405033A Expired - Lifetime US3882806A (en) 1972-10-20 1973-10-10 Cover thread pulling and take-up device for multineedle sewing machines

Country Status (7)

Country Link
US (1) US3882806A (OSRAM)
JP (1) JPS5433188B2 (OSRAM)
DE (1) DE2349510C3 (OSRAM)
ES (1) ES419785A1 (OSRAM)
FR (1) FR2203898B1 (OSRAM)
GB (1) GB1428697A (OSRAM)
IT (1) IT969729B (OSRAM)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050262764A1 (en) * 1996-02-26 2005-12-01 Weder Donald E Sleeve with curved lower end
US20070026570A1 (en) * 2004-03-29 2007-02-01 Articulated Technologies, Llc Roll-to-roll fabricated electronically active device
US20110030596A1 (en) * 2009-08-05 2011-02-10 Faurecia Automotive Seating, Inc. Flat seam construction for automotive upholstery
US8220401B2 (en) 2008-09-26 2012-07-17 Yamato Mishin Seizo Kabushiki Kaisha Sewing machine for covering chain stitch
TWI400375B (zh) * 2010-09-09 2013-07-01 Asiatic Fiber Corp Fabric manufacturing method and the fabric

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10138178B4 (de) * 2001-08-03 2004-07-15 Faurecia Autositze Gmbh & Co. Kg Verfahren zum Ausbilden einer Nahtanordnung und Sitzbezuganordnung

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1133608A (en) * 1910-11-02 1915-03-30 Singer Mfg Co Sewing-machine.
US1557135A (en) * 1921-05-31 1925-10-13 Union Special Machine Co Thread-controlling mechanism for sewing machines
US1711483A (en) * 1927-02-12 1929-05-07 Singer Mfg Co Thread-controlling mechanism for buttonhole-sewing machines
US2174205A (en) * 1935-02-21 1939-09-26 Mauser Werke Ag Method of and apparatus for performing looping on a multineedle seam covering sewing machine
US2350965A (en) * 1943-04-30 1944-06-06 Singer Mfg Co Looper thread controlling mechanism for sewing machines
US2996023A (en) * 1958-07-30 1961-08-15 Duerkoppwerke Multi-needle sewing machines

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1133608A (en) * 1910-11-02 1915-03-30 Singer Mfg Co Sewing-machine.
US1557135A (en) * 1921-05-31 1925-10-13 Union Special Machine Co Thread-controlling mechanism for sewing machines
US1711483A (en) * 1927-02-12 1929-05-07 Singer Mfg Co Thread-controlling mechanism for buttonhole-sewing machines
US2174205A (en) * 1935-02-21 1939-09-26 Mauser Werke Ag Method of and apparatus for performing looping on a multineedle seam covering sewing machine
US2350965A (en) * 1943-04-30 1944-06-06 Singer Mfg Co Looper thread controlling mechanism for sewing machines
US2996023A (en) * 1958-07-30 1961-08-15 Duerkoppwerke Multi-needle sewing machines

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050262764A1 (en) * 1996-02-26 2005-12-01 Weder Donald E Sleeve with curved lower end
US20070026570A1 (en) * 2004-03-29 2007-02-01 Articulated Technologies, Llc Roll-to-roll fabricated electronically active device
US8220401B2 (en) 2008-09-26 2012-07-17 Yamato Mishin Seizo Kabushiki Kaisha Sewing machine for covering chain stitch
TWI479061B (zh) * 2008-09-26 2015-04-01 Yamato Sewing Machine Mfg Flat seam sewing machine
US20110030596A1 (en) * 2009-08-05 2011-02-10 Faurecia Automotive Seating, Inc. Flat seam construction for automotive upholstery
US8316785B2 (en) * 2009-08-05 2012-11-27 Faurecia Automotive Seating, Llc Flat seam construction for automotive upholstery
TWI400375B (zh) * 2010-09-09 2013-07-01 Asiatic Fiber Corp Fabric manufacturing method and the fabric

Also Published As

Publication number Publication date
JPS4994456A (OSRAM) 1974-09-07
DE2349510B2 (de) 1978-07-06
DE2349510A1 (de) 1974-05-02
IT969729B (it) 1974-04-10
FR2203898A1 (OSRAM) 1974-05-17
ES419785A1 (es) 1976-03-16
JPS5433188B2 (OSRAM) 1979-10-18
DE2349510C3 (de) 1979-03-15
GB1428697A (en) 1976-03-17
FR2203898B1 (OSRAM) 1974-11-08

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