US2505523A - Retaining device for rotary hooks - Google Patents

Retaining device for rotary hooks Download PDF

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Publication number
US2505523A
US2505523A US650769A US65076946A US2505523A US 2505523 A US2505523 A US 2505523A US 650769 A US650769 A US 650769A US 65076946 A US65076946 A US 65076946A US 2505523 A US2505523 A US 2505523A
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US
United States
Prior art keywords
bobbin
shaft
rotary
stops
hook
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Expired - Lifetime
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US650769A
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English (en)
Inventor
Robert Ramon Casas
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 S A Beiningen
Original Assignee
Mefina S A Beiningen
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Publication date
Application filed by Mefina S A Beiningen filed Critical Mefina S A Beiningen
Application granted granted Critical
Publication of US2505523A publication Critical patent/US2505523A/en
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Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B27/00—Work-feeding means
    • D05B27/22—Work-feeding means with means for setting length of stitch
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B57/00—Loop takers, e.g. loopers
    • D05B57/08—Loop takers, e.g. loopers for lock-stitch sewing machines
    • D05B57/10—Shuttles
    • D05B57/14—Shuttles with rotary hooks
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05D—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES D05B AND D05C, RELATING TO SEWING, EMBROIDERING AND TUFTING
    • D05D2205/00—Interface between the operator and the machine
    • D05D2205/12—Machine to the operator; Alarms
    • D05D2205/16—Display arrangements

Definitions

  • the present invention relates to an improvement in sewing machines having a rotary hook.
  • a device generally consists of two essential parts, viz. an inner part called the bobbin holder and adapted to support the bobbin, and an outer part rotating around the bobbin and carrying a hook for catching the loop formed by the upper thread and for passing the latter around the bobbin.
  • the outer part also serves as a support and guide for the bobbin holder and would take the latter with it in its own rotary movement, if it was not for a retaining device which prevents this action and which maintains the bobbin holder stationary.
  • the simplest means consist in providing the bcbbin holder with an extension, bearing against a fixed stop located in the path of the aforementioned extension. As this stop prevents rotation in one direction only, the bobbin holder is free to rotate in the opposite direction for a fraction of a revolution at least.
  • Such a device affords the possibility of removing the goods being sewn from the machine at standstill, without the upper thread remaining hooked in the rotary hook, but it has the inconvenience that, for every stitch, the upper thread having to make its way between said extension and stop, it must overcome an appreciable resistance, varying among other things with the rotational speed of the rotary hook. The upper thread is thus periodically subjected to sudden tensions, caus ing irregular seams, and noisy operation.
  • retaining devices For the purpose of avoidingr these inconveniences, numerous retaining devices of various types have been suggested. Most of them have a stop intended to co-cperate with bearing surfaces provided on the bobbin holder, said stop being periodically caused to leave the cooperating bearing surface in order to leave a free for the upper thread during its travel round the bobbin. Some of these retaining devices comprise two stops, one of them remaining in a fixed position, the other one being carried by a rock ing arm, which periodically imparts a backward movement to the bobbln holder for the purpose of liberating the passage in front of the first stop. rIhissolution has the disadvantage of subjecting the bob'oin holder to oscillations which cause ob jectionable vibrations.
  • swinging or rotating members are used having extensions reaching into recesses provided in the bobbin holder for the purpose of keeping same stationary, said extensions leaving periodically the corresponding recess to allow a free passage way for the upper thread.
  • the stops are provided on the periphery of the rotary hook at points which are either diametrically opposite to each other with respect to the axis of the rotary hook, or located on the same side of a plane passing through the rotary hook and needle axis.
  • This arrangement has the inconvenience of making only a small fraction of the duration of a revolution of the rotary hook available for the period of oscillation or rotation of said retaining device. This means, that the latter must move at a rather high speed and that the resulting stopping forces exerted on the bobbin holder vary in magnitude and direction thus causing very disturbing vibrations.
  • the retaining device, forming the object of this invention7 is free from the aforementioned inconveniences.
  • t is distinguished from other retaining devices known, by two bobbin-holder prongs located in close vicinity and on two opposite sides of the needle, and on two different paths around the axis of said rotary hook and by two stops provided each with a single bearing face acting individually on the respective prong so as to continually prevent a rotational displacement of said bobbin-holder in the direction followed by the revolving part of said rotary hooi; and so as to allow at standstill of said machine said bobbinholder to perform a substantial rotational displacement in the opposite direction under the action ofva slight pull exerted on said upper thread, thus allowing the work to be removed from said 55 machine at standstill.
  • Figs. l, 2 and 3 are perspective views of the devce' seen in three'differentworking positions.
  • Fig. 4 is a'plan viewoffa portion of thel device.
  • Fig. 5 is a-perspective view of the device shown 0with its connections to "a work ⁇ feeding L HnisrnY of -a sewingv ⁇ machine.
  • rotary Vhook comprisesfa-,rotary anda stationary part.
  • the rotaryzpart comprises-a cup l l, whose :cylindrical part is cut awayat l2 so as'to forni a hook i3, substantiallytangential to the needle iii of aV sewing machine not shown.
  • Said cup l l Vis mounted rigidly on a shaft l5 driven in rotation by a shaft I6 in the'direction of 'the arrow by ⁇ means of two bevel gearsl'l and I8.
  • the bobbinfholderis provided with a. horizontal extension23 cut -awayisotasto form two-.prongs 24 and 25 buttingagainst-.two bearing faces 2.5i
  • the other ⁇ end of-said lever ismaintaned in continuous contact with cam 29 by a springl 32wound on shaft 2,8, one end ofsaidspringresting onaiixed point, :the other end being held 'gon lever 3l;by faprong 33.
  • Shaft 28 has, riveted to;it,-anarm 35i vlrithgan offset vane 35 and a groove, guiding a regulatable lil small plate 36.
  • a clamping screw 37 allows the aforementioned plate to be adjusted relative to the shaft 28.
  • the surfaces 26 and 21 acting as stops for the prongs 24 and 25 are provided respectively on the edges of vane 35 and sliding plate 36.
  • the surfaces of contact between stops and prongs are chosen on two different radii with respect to the rotary hook .axis so as-.tovbe located on diierent paths around said axis.
  • Said surfaces or butting faces 25 and 2l are portions Aof f conical surfaces having their axmcoincidingf with that of shaft 253 as shown in Fig. 4.
  • the 'result of this arrangement is that thepoint of contact. of each of said but-ting faces lwithlits .corresponding bobbin-holder prong 24 and,25has its instantaneous motion directed in the plane tangent to said butting face at said point of contact.
  • saidfcontactfpoints between said stops and said prongs are located vat twopoints practically vopposite toA one another with'respect to the needle axis TM "(seeFigfci, one in back and one in frontloflsaidvaxis). Stops 25 and 2l thusprevent bobbimholder i9 from 'being frictionally carried aroundbycupllfl.
  • Fig. l shows the ⁇ device-at the ⁇ momentfarm Vtl'reaches the upperdeadv pointof itsY movement.
  • Rear stop 2'! is in contact with'rear prong 25 and maintains bobbineholder lsstaticnary. "Loop22 justv formed bythe needle in its upwardmovement betweenprongs 221 and 25 has'been caught'by Anlagenr prong 25 still bears against.buttingfaceZl.
  • Fig. 3 shows thedevice shortly 4before .arm .34
  • arm 34 has its motion reversed
  • Both stops are placed in the immediate vicinity and on two opposite sides of the needle axis, the entrance of the loop being located in front ⁇ of the needle axis and the exit of the loop being located in back of the needle axis.
  • This arrangement affords the largest possible time-interval between the instants of opening of the passage ways for the entrance and for the exit of the upper thread, thus allowing for a comparatively large amplitude for a, reasonably small velocity of the oscillating stops to be chosen.
  • the forces exerted by them on the prongs 0f the bobbin-holder have substantially the same magnitude and direction for all positions of said stops. There is thus no alternating force capable of causing vibrations of the bobbin-holder.
  • FIG. 5 shows by way of example, how the described device can be combined with an automatic work-feeding mechanism of compact design.
  • the oscillating member of the bobbin-holder retaining device and the automatic feeding mechanisrn are operated in common by eccentric 29 fastened to driving shaft I6.
  • the feeding of the Work is produced by a toothed plate 4
  • arm 48 On its upper part, arm
  • Fork shaped member 44 imparts a substantially vertical motion to toothed plate 4
  • a rotary hook having an axis of rotation parallel to the path of reciprocation of the needle, said rotary hook including a rotary member having a hook and a recess, a bobbin carrier mounted in said recess,.
  • a shaft for rotating said rotary member about its axis a pair of spaced arms extending substantially radially outwardly from the bobbin carrier beyond the rotary hook, a pair of movable stops cooperating with said arms to prevent rotation of the bobbin carrier in the direction of rotation of the rotary hook, and means for oscillating said stops in a direction generally parallel to the shaft for driving the rotary member tov alternately position one stop in engagement with its cooperating arm and move the other stop away from contact with its cooperating arm to enable a thread loop to pass between the same.
  • a sewing machine having a reciprocating cluding a rotary member having a hook and a recess, a bobbin carrier mounted in said recess, a shaft for rotating said rotary member about its axis, a pair of spaced arms extending substantially radially outwardly from the bobbin carrier' beyond the rotary hook, a pair of movable stops cooperating with saidarmg to prevent rotation of Athe bobbin carrier in the direction of rotation.4 of the rotary hook, and means for oscillating and d.
  • said stops in "a direction generally parallel'to ⁇ the sh'aft for driving the rotary member to alternately position one stop in engagementv with its cooperating arm and move the other stop away from contact with its cooperating arm to enable a thread loop to pass between the same, said oscillating means beingdriven at a speed relative tothe rotary member driving shaft such thatl the rotary member ymakes two revolutions for each to and fro movement of the stops.
  • a rotary hook having an axis of rotation parallel to the path of reciprocation of the needle, said rotary hook including a rotary member having a hook anda' recess, a bobbin carrier mountedin said recess,
  • a: shaft for rotating said rotary member aboutv enable a thread loop to pass between the same
  • saidl means comprising an oscillating shaft positioned perpendicularly to the shaft driving the rotary member and carrying said stops, a crank arm fixed to the oscillating shaft, a cam shaft, a cam on the cam shaft cooperating with the crank arm for driving the oscillating shaft, transmission rneans connecting the cam shaft to the shaft driving the rotary member so that the cam shaft rotates at 1/'2 the speed of rotation of the other shaft, and the stops make a single to and fro movement for each two revolutions of the rotary hook carrying member.
  • a rotary hook having an axis of rotation parallel to the path of reciprocation of the needle, said rotary hook including a rotary member having a hook and a recess, a bobbin carrier mounted in said recess, a shaft for rotating said rotary member about its axis, a pair of spaced arms extending substantially radially outwardly from the bobbin carrier beyond the rotary hook, a pair of movable stops cooperating with said arms to prevent rotation of the bobbin carrier in the direction of rotation of the rotary hook, and means for oscillate ir'ig said stopsl in a direction generally parallel to the shaft for driving the rotary member to alternately position one stop in engagement with its cooperating arm and move the other stop away from contact with its cooperating arm to enable a thread loop to pass between the same; said stops each having a single engaging surface co acting individually with the arms, said stops being located at different distances
  • a rotary hook 'hav'- ingan axis of rotation parallel to the pathfoff' reciprocation of the'needle said rotary hook including a rotary member having a hook and aV recess, a bobbin carrier mounted in said recess, a shaft for rotating said rotary member about its axis, a pair of spaced arms extending sub-v stantially radially outwardly from the bobbin carrier beyond the rotary hook, a pair of movable stops cooperating with said arms to prevent rotation of the bobbin carrier in the direction of rotation of the rotary hook, and means foroscillating said stops in a direction generally parallel to the shaft for driving the rotary member to alternately position one stop in engagement with its cooperating arm and move the other stop away from contact with its cooperating arm to enable a thread loop to pass-between the same, said stops each having a contact surface movable along the arc of a circle tangent to the cooperating surface ofthe
  • a rotary hook having an vaxis of rotation parallel to the path of reciprocation of the needle, said rotary hook including a rotary member having a hook and a recess, a bobbin carrier mounted in said recess, a shaft for rotating said rotary memberrabout its axis, a pair of spaced arms extending substantially radially outwardly from the bobbin carrier beyondthe rotary hook, a pair of movable stops cooperating with said arms to prevent rotation of the bobbin carrier in the direction of rotation of the rotary hook, and means for oscillating said stops in a direction generally parallel to the shaft for driving the rotary 'member4 to alternately Apositi'onV onestop in engagement with its cooperating arm and move the other stop away from contact with its cooperating Aarm to enable a thread loop to pass between the same, said means comprising anoscillating shaft positioned perpendicn

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
US650769A 1945-04-18 1946-02-28 Retaining device for rotary hooks Expired - Lifetime US2505523A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH608983X 1945-04-18

Publications (1)

Publication Number Publication Date
US2505523A true US2505523A (en) 1950-04-25

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Family Applications (1)

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US650769A Expired - Lifetime US2505523A (en) 1945-04-18 1946-02-28 Retaining device for rotary hooks

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US (1) US2505523A (en(2012))
BE (1) BE463406A (en(2012))
CH (1) CH246234A (en(2012))
ES (1) ES173259A1 (en(2012))
FR (1) FR923106A (en(2012))
GB (1) GB608983A (en(2012))
NL (1) NL64892C (en(2012))

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2966130A (en) * 1954-11-29 1960-12-27 Singer Mfg Co Sewing machine and loop-taker mechanisms therefor
US3217678A (en) * 1962-09-14 1965-11-16 Mefina Sa Shuttle device having a rotating hook for a sewing machine
US4091753A (en) * 1977-01-13 1978-05-30 The Singer Company Bobbin thread pull-off for lockstitch looptaker

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2236830A (en) * 1939-10-14 1941-04-01 Singer Mfg Co Loop-taker mechanism for sewing machines

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2236830A (en) * 1939-10-14 1941-04-01 Singer Mfg Co Loop-taker mechanism for sewing machines

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2966130A (en) * 1954-11-29 1960-12-27 Singer Mfg Co Sewing machine and loop-taker mechanisms therefor
US3217678A (en) * 1962-09-14 1965-11-16 Mefina Sa Shuttle device having a rotating hook for a sewing machine
US4091753A (en) * 1977-01-13 1978-05-30 The Singer Company Bobbin thread pull-off for lockstitch looptaker

Also Published As

Publication number Publication date
CH246234A (fr) 1946-12-31
NL64892C (en(2012)) 1949-12-15
ES173259A1 (es) 1946-05-16
FR923106A (fr) 1947-06-27
BE463406A (en(2012)) 1946-03-30
GB608983A (en) 1948-09-23

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