US3557731A - System for adjusting the tension of the upper thread in a sewing machine - Google Patents

System for adjusting the tension of the upper thread in a sewing machine Download PDF

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Publication number
US3557731A
US3557731A US879417A US3557731DA US3557731A US 3557731 A US3557731 A US 3557731A US 879417 A US879417 A US 879417A US 3557731D A US3557731D A US 3557731DA US 3557731 A US3557731 A US 3557731A
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United States
Prior art keywords
spring
thread
spindle
lever
carried
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
US879417A
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English (en)
Inventor
Ramon Casas-Robert
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.)
Mefina SA
Original Assignee
Mefina SA
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Publication date
Application filed by Mefina SA filed Critical Mefina SA
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Publication of US3557731A publication Critical patent/US3557731A/en
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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B47/00—Needle-thread tensioning devices; Applications of tensometers
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B73/00—Casings
    • D05B73/005—Doors or covers for accessing inner parts of the machine; Security devices therefor

Definitions

  • ABSTRACT A system for adjusting the tensile stress to which the upper thread of the machine is subjected by means of a spring engaging an arrangement including a spindle carrying two plates between which the thread is held against friction during its progression from its spool towards the needle.
  • the adjustment of the spring is ensured by means of two levers connecting corresponding points of the spring respectively with the spindle of said arrangement and with the cam normally controlling the actual tensioning of the spring.
  • the present invention has for its object a system for adjusting the tension of the upper thread in a sewing machine, said system including at least two plates fitted on a common spindle and adapted to be urged into contacting relationship over the thread by a spring acting on said plate while a knurled ad justing wheel controls a cam the angular position of which acts on the tension of the spring.
  • the adjusting system includes a furthermore first lever fitted between the cam and a point of the spring, while a second lever is inserted between a second point of the spring and the spindle over which the superposed plates are to be clamped together.
  • Such an adjusting system provides a very high accuracy and an extremely fine adjustment of the tension of the upper thread since the adjusting cam acts on the tensioning spring at a theoretically selected point thereof as provided by the presence of the intermediate levers between said cam and the spindle over which the plates are fitted.
  • FIG. 1 is a partly side elevational view and partly a longitudinal cross section of the upper part of the frame of a sewing machine incorporating the tension-adjusting means according to the invention
  • FIG. 2 is a sectional view through line 11-" of FIG. 1;
  • FIG. 3 is a view from above the head of the sewing machine
  • FIG. 4 is a view from above, partly torn off, of a portion of the head of the sewing machine.
  • the sewing machine illustrated in the drawings includes a frame 1, the upper surface 2 of which carries the tension-adjusting system generally designated by the reference number 3.
  • Said tension-adjusting system provided for the upper thread 4 of the sewing machine includes two plates 5 fill fitted in superposition round a spindle 6 adapted to slide vertically in a bearing 7 forming part of the frame 1.
  • a blade spring 8 urges the two plates 5 into contacting relationship while a knurled wheel 9 adapted to revolve round a spindle 10 carried by the frame 1 serves as a member controlling the tension-adjusting system.
  • Said outline of the cam 11 is provided furthermore with notches l2 defining in cooperation with the end 13 of the first lever 14 as many tension-adjusting positions.
  • Said lever 14 is adapted to rock round a pivot 15 rigid with the frame 1 of the sewing machine.
  • the end 16 of the lever 14 facing away from the cam carries two raised lugs 17 through which said lever 14 is pivotally carried by the above-mentioned pivot 15.
  • the spring 8 engages through its outer end 18 the underside of said pivot 15.
  • the other end 19 of the spring 8 is connected through an adjusting screw 20 with an intermediate section 21 of the first-mentioned lever 14.
  • a nut 22 fitted on the screw 20 gauges or adjusts at the start the tension of the spring 8.
  • a second lever 23 also carries lugs 24 through which it is revolvably secured to the pivot 15 adjacent the lever 14.
  • the free end 25 of said second lever 23 terminates as a fork provided with two tines and engaging a groove 26 formed in the plate-carrying spindle 6.
  • Said second lever 23 includes a transverse section 27 extending laterally underneath the spring 8 and bearing against an intermediate point of the length of said spring 8.
  • the periphery of the knurled wheel 9 carries a scale 30 whereby it is possible for the sempstress to ascertain, on the outside of the frame 1 the value of the adjustment selected for the tension of the upper thread 4.
  • the spool 31 off which the upper thread is unwound is fitted over a spool carrier spindle 32 located in a housing 33 provided in the head of the sewing machine (FIG. 1).
  • Steel spring wires 34 are wound round the spool-carrying spindle 32 so as to hold fast if required the spool 31 with reference to its carrier spindle 32 while a cap 35 rests over the spool 31 so as to guide the thread 4 in its upward direction during its unwinding.
  • the thread 4 passes through the upper surface 2 of the frame 1 as provided by a slot 36 (FIG. 3), beyond which it engages the gap between the plates 5.
  • the thread 4 passing out of said gap engages a thread guide 37 constituted by a bent trough beyond which the thread reaches the front surface of the frame 1 of the sewing machine, on which it engages a further thread guide 38 and a compensating spring 39, the thread engaging then after a thread-drawing lever 40 concealed by a cover 41.
  • the latter is provided with a slot through which the thread issues so as to engage further thread guides 42 and 43 and to finally reach the needle clamping means and the needle eye, which are not illustrated, over the needle bar 44.
  • the upper surface 2 of the frame 1 of the sewing machine carries also a thread guide 45 constituted by a blade projecting above the upper surface 2 of the frame Said thread guide 45 constrains the thread to follow a path extending in the medial plane passing through the cop 51.
  • said thread guide 45 forms the raised end of a metal strip 46 folded in U-shpae and housed within the frame 1.
  • a screw 47 engages transversely a port 48 formed in the upper surface 2 of the frame and extends freely through one of the arms of the U-sliaped strip 46 so as to be screwed in the opposite arm of the latter.
  • the raised end 49 of the metal strip passes through a slot 50 cut in the frame 1 and forms the thread guide 45. It will be readily ascertained from inspection of the drawings that the fastening or release of the screw 47 urges more or less together the arms of the U-shaped strip 46 whereby the raised'end 49 projects more or less considerably above the upper surface 2 of the frame 1.
  • the sewing machine illustrated by way of example may also be provided on the upper surface 2 of its frame 1 with a second spool-carrying spindle 53 adapted to carry a further spool 54.
  • This allows the cop 51 to be wound with a thread 55 fed by said second spool 54.
  • the thread 55 is drawn over the thread guide 45 and engages the gap between the plates 5 of the tension-adjusting system 3, following which the thread 55 is fed again over the thread guide 45 onto the cop 5 1.
  • the lever 56 controlling the operation of the presser bar 57 holding the fabric in position serves also, in the case of the machine illustrated, as a member acting through the agency of a connecting rod 58 on the tension-adjusting system 3 in order to obtain the opening of the plates 5 each time the presser bar 57 is raised.
  • the connecting rod 58 is secured through the agency of a pivot 59 to an intermediate point of the lever 656 which is secured to the pivot 60 rigid with the machine frame.
  • the upper end 61 of the connecting rod 58 engages an opening 62 formed in the lever 23 (FIG. 4).
  • a shoulder 63 is provided on the connecting rod 58 so as to raise said lever 23 and therewith the spindle 6 each time the lever 56 controlling the presser bar 57 is raised. It should be remarked that, when said lever 56 is raised, the pivot 59 is shifted towards the opposite side of the geometrical line connecting the shoulder 63 with the pivot 60 which ensures a stable condition on the one hand for the fabric holding the lever 56 in its raised position and on the other hand for the spindle 6 in its plate-releasing position.
  • the two levers I4 and 23 instead of being set side by side, may be arranged in superposition or possibly they may be pivotally connected each with a different pivot carried by the frame I of the sewing machine.
  • the arrangement disclosed with reference to the accompanying drawings provides a very compact structure of the tension-adjusting system which furthers the assembly of the different components in the upper part of the frame 1 without disturbing by any means the remaining mechanism of the sewing machine.
  • the knurled wheel 9 instead of being revolvably carried by a horizontal spindle I0 arallel with the axis of the pivot 18 provided for the levers 4 and 23, may as well be fitted so as to pivot round a vertical spindle in which case the cam Ill forms a bell-shaped cam operating along a vertical component on the end 113 of the lever 14.
  • a system adjusting the tension of the upper thread and comprising a spindle carried by the frame, at least two thread-tensioning plates carried by the spindle and between which the thread progresses under friction on its path between the spool and the needle, a spring acting on the spindle and plate arrangement, an adjusting knurled wheel revolvably carried by the machine body, a cam controlled by said wheel, a first lever operatively connecting the cam with a first point of the spring, and a second lever engaging a second point on said spring and connecting in turn with said spindle, whereby movement of said cam adjusts in accordance with its angular position the tension exerted by said spring and consequently the tensile stress of the upper thread.
  • the spring is a blade spring, said spring comprising a common axis carried by the machine body and pivotally carrying both the first and second lever and one end 'of the blade spring, the two levers being set side by side on said axis, and an adjustable screw connecting an intermediate point of the first lever with the first point of the spring adjacent the end of the latter, the second lever including a lateral projection engaging said second point of the spring and the end of said second lever engaging the plate-carrying spindle.
  • the spring is a blade spring, said spring comprising a common axis carried by the machine body, and pivotally carrying both the first and second lever and one end of the blade spring, an adjustable screw connecting an intermediate point of the first lever with the first point of the spring adjacent the end of the latter, an auxiliary spindle parallel with said common axis and rigid with the knurled wheel and cam.
  • cam outline is provided with notches adapted to engage selectively the end of the first lever to define corresponding tensile stresses for the spring.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
  • Tension Adjustment In Filamentary Materials (AREA)
US879417A 1968-12-06 1969-11-24 System for adjusting the tension of the upper thread in a sewing machine Expired - Lifetime US3557731A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1824068A CH485901A (fr) 1968-12-06 1968-12-06 Dispositif de réglage de la tension du fil supérieur d'une machine à coudre

Publications (1)

Publication Number Publication Date
US3557731A true US3557731A (en) 1971-01-26

Family

ID=4431546

Family Applications (1)

Application Number Title Priority Date Filing Date
US879417A Expired - Lifetime US3557731A (en) 1968-12-06 1969-11-24 System for adjusting the tension of the upper thread in a sewing machine

Country Status (14)

Country Link
US (1) US3557731A (enrdf_load_stackoverflow)
JP (1) JPS5218621B1 (enrdf_load_stackoverflow)
AT (2) AT304239B (enrdf_load_stackoverflow)
BE (1) BE741592A (enrdf_load_stackoverflow)
BR (1) BR6914674D0 (enrdf_load_stackoverflow)
CH (1) CH485901A (enrdf_load_stackoverflow)
DE (1) DE1960665A1 (enrdf_load_stackoverflow)
DK (1) DK133562B (enrdf_load_stackoverflow)
ES (1) ES373934A1 (enrdf_load_stackoverflow)
FR (1) FR2025493A1 (enrdf_load_stackoverflow)
GB (1) GB1257133A (enrdf_load_stackoverflow)
IE (1) IE33859B1 (enrdf_load_stackoverflow)
NL (1) NL6918227A (enrdf_load_stackoverflow)
SE (1) SE357985B (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3721205A (en) * 1970-02-09 1973-03-20 Aisin Seiki Tension device for a sewing machine
US3841248A (en) * 1973-07-23 1974-10-15 Singer Co Needle thread tensioning module for lock stitch sewing machines
US3863581A (en) * 1972-09-13 1975-02-04 Maruzen Sewing Machine Thread tensioning device for sewing machines
US3978802A (en) * 1974-11-08 1976-09-07 White Sewing Machine Company Sewing machine thread tensioner
US4141306A (en) * 1976-12-10 1979-02-27 The Singer Company Thread tensioning apparatus for sewing machines
US4180006A (en) * 1978-03-31 1979-12-25 The Singer Company Tension selecting mechanism for sewing machines
US4221180A (en) * 1977-09-21 1980-09-09 The Singer Company Compact upper thread tension device
US4372502A (en) * 1981-03-23 1983-02-08 The Singer Company Adjustable thread tensioning device for a sewing machine
US4453480A (en) * 1983-07-11 1984-06-12 The Singer Company Thread tensioning module for a sewing machine
RU2202017C1 (ru) * 2002-04-30 2003-04-10 Общество с ограниченной ответственностью "Завод бытовых швейных машин" Регулятор натяжения нитки иглы на швейных машинах

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5902969B2 (ja) * 2012-03-10 2016-04-13 蛇の目ミシン工業株式会社 収納式の糸立て台のための下糸巻きガイドを備えたミシン

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1234322A (en) * 1915-10-08 1917-07-24 Singer Mfg Co Needle-thread-controlling device for sewing-machines.
US1518494A (en) * 1922-05-02 1924-12-09 Elcock Robert Tensioning device for sewing machines
US2609772A (en) * 1948-12-20 1952-09-09 Mefina Sa Sewing machine
CA562397A (en) * 1958-08-26 Kleemann Karl Thread tension release mechanism for sewing machines

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA562397A (en) * 1958-08-26 Kleemann Karl Thread tension release mechanism for sewing machines
US1234322A (en) * 1915-10-08 1917-07-24 Singer Mfg Co Needle-thread-controlling device for sewing-machines.
US1518494A (en) * 1922-05-02 1924-12-09 Elcock Robert Tensioning device for sewing machines
US2609772A (en) * 1948-12-20 1952-09-09 Mefina Sa Sewing machine

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3721205A (en) * 1970-02-09 1973-03-20 Aisin Seiki Tension device for a sewing machine
US3863581A (en) * 1972-09-13 1975-02-04 Maruzen Sewing Machine Thread tensioning device for sewing machines
US3841248A (en) * 1973-07-23 1974-10-15 Singer Co Needle thread tensioning module for lock stitch sewing machines
US3978802A (en) * 1974-11-08 1976-09-07 White Sewing Machine Company Sewing machine thread tensioner
US4141306A (en) * 1976-12-10 1979-02-27 The Singer Company Thread tensioning apparatus for sewing machines
US4221180A (en) * 1977-09-21 1980-09-09 The Singer Company Compact upper thread tension device
US4180006A (en) * 1978-03-31 1979-12-25 The Singer Company Tension selecting mechanism for sewing machines
US4372502A (en) * 1981-03-23 1983-02-08 The Singer Company Adjustable thread tensioning device for a sewing machine
US4453480A (en) * 1983-07-11 1984-06-12 The Singer Company Thread tensioning module for a sewing machine
RU2202017C1 (ru) * 2002-04-30 2003-04-10 Общество с ограниченной ответственностью "Завод бытовых швейных машин" Регулятор натяжения нитки иглы на швейных машинах

Also Published As

Publication number Publication date
DK133562C (enrdf_load_stackoverflow) 1976-12-06
AT314951B (de) 1974-05-10
GB1257133A (enrdf_load_stackoverflow) 1971-12-15
SE357985B (enrdf_load_stackoverflow) 1973-07-16
CH485901A (fr) 1970-02-15
ES373934A1 (es) 1972-03-16
IE33859L (en) 1970-05-06
FR2025493A1 (enrdf_load_stackoverflow) 1970-09-11
DE1960665A1 (de) 1970-06-18
DK133562B (da) 1976-06-08
NL6918227A (enrdf_load_stackoverflow) 1970-06-09
BE741592A (enrdf_load_stackoverflow) 1970-04-16
BR6914674D0 (pt) 1973-01-11
IE33859B1 (en) 1974-11-27
AT304239B (de) 1972-12-27
JPS5218621B1 (enrdf_load_stackoverflow) 1977-05-23

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