US1895257A - Sewing machine - Google Patents

Description

' Jan. 24, 1933.

w. T. MINETT 1,895,257

SEWING MACHINE Filed Sept. 19, 1930 wees /a acwmw Mada/ 7 1,169,909 dated February 1,1916. The mas Patented Jan. 24, 1933 WJILERID moms mania r .LEIQE E i L Nn e s sr n ror-ris r shot;

omcnmnar corromr m-or eters n Jar-sax a iorrsv'aesmr r J BS X Application filed-September 19, 1930 fierialfli'fo,

This invention concerned with improvements in or relating to sewing 111301111165? and is particularly concerned with the 'locking thread mechanism of lockstitc'h sewing-machines.

as shown in the patent to As'hworth No,

chine'shown in this patent makes useof a r0 tary loop taker in the form of a irotaryihook having a 'loop talking :beak and ihousing within it a-spool of thread .on a :bobbin in a case therefor, the bobbin being held against rotation-with :the loop taker and 'a'looploi under-- thread 'beingtaken up by the "beak during the sewing of a-seam andoarried around the:-bob-" bincase and over the thread issuing from the bobbin Ito :torm a =l0ckstitch. "In such a maco-operate With-thejlocptaker in the sewing" chine it has been usual toprovide pins which engagethe hobbincasetmhold the latter (and therefore the :bobbin within it) against rotation withythe loop takerwand a cam ring ;has

usually been :provided which extends round the interior :of the bobbin (-case housingin the loop taker-and whichactstoengagesaid pins during the rotation of the loop taker and moves them alternately away from engage:

ment with the bobbinicasezto allow the loop-of.

under-thread to pass round the :bobbinfcase without beingobstructed by the pins. The presence of the cam ringwithin the bobbincase housing notably decreases the internal ofthe'lockstitch seam.

One of the several objects ojf the present invention is-torprovide a loopdaaker suitable ing a bobbin ofo'threadguand .7

S WING MACHINE 3, 5. d firs inan wer a 22.:

for ;use' in a machine of the kind hereinbefore indicated which will be so arranged as to *be capable-of 'ihousing within it ia ibobbi-nbzt "larger thread-hold ng capacity than usual hitherto but gwhichwill ha ve external dimen.-"- akers at present si ons similar to those of loop I in general use in such machines,

Another of the severaliobjects of suitable 'for use in' .a lockstit'oh :shoe sewing machine that itwil'l'he simplifiedand of more the preS V- ent-lnvent on is so to arrange a loop taker I robust construction than heretotore 1is1ial.

In .order ithatvthe :presentinvention mayghe more clearly understood there willnowbe de scribed, by Wayof example "onlyar dlwithr e'iierence to the @QCOIIlpanyln-g drawing one constructlon, assumed to'ibe i'or .use in fa machine o as deseribedin'said patent whichfis 1114mm:

Inlthe drawing.

tive ofthevariousfeatures otthe invention."

Figure 1 is a sideelevation, partly in section,"showingga loop taker embodying Jfeatures of the 'present invention and wetti Figure2 is apl-an view of .thetloop talier seen in Figurel. '1'

"i The illustrative loop takerflcompris es I tubularibody ,1 providing within ita housing I 3 fora spool oi'ithread .on a bobbin bl, A ring-like member :7 is secured, by screws, to

one end 7 of the body 1 a sshown iand extends around the greater part of its iperiph ery and has at one endithereof a aloopvtakingzbeakil.

Closeto the lopposite end of the 10 0p taken r bodvithe glatter is jprovidedaroundits' peripherjwith bevelled :gear teeth l3 withkwhich the driving ipinion is adapted toymeshlr A shoulder 15 provided around the inside of the ring-like member 7 is adapted to itorm with the adjacente'nd tace of thezloop taker ia' rectangular groove as shown, The bobbin case 17 has aperipheral rib :19 therein-which 3 is adapted to be received within the-{said groove to :PQSitiontheQbQbbin ease within Y the 0p nk ihe' b bb n ;a e {sp t sleeve 21 extending axially thereof and upon:

thissleeve the bobbin ois adapted to fitiwithi 7 it during its rotation. The said sleeve 29 is tending axially from it a sleeve 29, theex: ternal'diameter of which is only very slightly less than the internal diameter of the loop taker so that the sleeve 'may ext end within the latter more or less tightly and support of such a length that when fitting within the looptakeritextends fairly closely up to the near end'of the bobbin case 17 but nevertheless leaves roombetween it and the bobbin case for aloop .of under=thread to; pass easily: around the bobbin. case. :Two" grooves are provided. in the peripheryloftlie sleeve 29 extending parallel to its. axis at more or less diametrically. opposite points 3 thereon. Sliding fingers 31 are housed with-' v I h pinsaway from-engagement with the bob-bin case at certain times, the cam ring has usually-w been positioned on the body l 'closetotthe T inv the said grooves and these fingers are of sucha length that they -may' extend beyond theinner face'of the sleeve, 29 for a substantial. distance while their-opposite ends are approximately flush'withthe outer face T01:

the-member 25. )The thickness of that part oflsaid fingerswhich extends intothe interiorof the'loop taker is more orlessequal ,totheidepth ofthe grooves so thatthe outer faces of theafingersiare more'for less 'level with the outer periphery of.- the sleeve 29.. :Rat trap springs 33 are provided on theiront ofthelmeniber 25. to bear against the outer.

' ends of the fingersi3l to urge them along their grooves toward thebobbincase IT. The bobbin case has slots: 85 cut'in that edge." thereof whichlies nearer to the fingers within whichjslots the inner ends of the said 1 fingers,31"may 'be receivedone or other of the fingers beingat all normal timesin its:

.slot; *This'arrangement ensuresjthatth'e bob- "rotation of the looptaker. To provide that;

bin casesha'll 'be held. stationary during the the said fingerssh all be withdrawn along their grooves away Efrem the bobbin case/ati appropriate times to. allow a loop 37 1 (see vFigure 1) 'of underthread picked Jupiby the loop taker beak 11 to passaroundthe'bobbin case in awell-known inannermthecylindrical i body lhas an thatend which surrounds the sleeve 29 a cam face 39 which projects axiallyf ofthe end otthe' cylindrical body a distanceofabout three sixteenthsf of an 'inch and ex tends around the "loop taker for about one x 'fa'ce: beingbevelledqasr shown in Fig. 2. Each.

third ofyits' periphery the ends of the cam shoulder llgwith. whichthe cam" 39is adapted to engage during-rotatioii'of theiloop taker;

A to; withdraw each finger in turn from itsf slot in thebobbin case in order, to allow the.

under-thread 37. 'to p'ass between theffinger "and the case asindicated inFigure 1 .Since as aforesaid the said fingers 31 arespaced approximately diametrically across the. sleeve w 29 and the cam 39 extends around the periph ery of the loop taker for about a third only of its length it will be understood that only cam rearwardly at any time so thatthebobbin case will at alltiines be held against rotation in spite of the withdrawal ,of one or other ofthe fingers. The bobbin itself' w'ill'therefore be held; against rotating with the loop one ofthe fingers 31 will be urged by the the loop: taker as. described instead. of onthe insidezof the housing. forthe b'obbi ncase it is possible to house: a bobb'inof consider-ably; "larger diameter'sin the loopitaker. In loop;

takersof thelkind hereinjbefore indicated 1 which have acam ringinside.the= =bobbin;

case housing for/withdrawing; the retainin 5.1

root of the beak 1-1 and it has beennecessaryr to provide'for. a substantial gapbetween'the.

rear edge o-the cam :and the i orward; end

or the. bobbin cas'e'axiallyv ofthe loop taker in. orderz to allow-the loop of-; -.u-nder-thread 1 to pass easily around the bobbin case between; the latter and;..the-cam ring. 1Tl1lS"f-Ct.i111i-.

the loop taker may therefore be considerably;

increased, the extent o-f the'increase being ilimite'd, chiefly by reason ofzthe 'it'act thatthe.

'loop of undebthreadmust slide easily from I the loop taking beak "(which isfixed in po he sition ".011 the shuttle) over the bobbin case and this becomes more difficult if the width of. the bobbin .isfvery largely increased.

loop "taker o f the internal cam-ring type above mentioned and adapted to fit into the machine described in the said-patent has f f usually carried a bobb n the dimensions of which were.approxi1nately, diameter, one" it and seventeen thirty-secondsof; an 'inch and width between thefla-nges, nine sinteenths' of an inch A loop takerof thesaine size:

constructed asabove indicatedflin.accordance 1.

with the present-inventioncan accominodateg i a-bobbin of which the dimensions areldianii eter one and nineteen thirty; seconds" at an f inch andwi'dth betweenflanges three qnz'zr; tersof aninch, showing an increased thread;

what is claimed is r f'-- The invention havingbeenthus described able for use in a shoe sewing machine, adaptthe loop taking b'ealr extending" axially of ed to move in a circular path and having the body and arranged to engage said fingers.

within it a housing for a spool of thread, of retaining means arranged to retain the spool against rotary movement with the loop taker and withdrawing means, exterior to the housing for the spool, for engaging said retaining means at a certain time during the sewing of a stitch to withdraw said retaining means from retaining position to allow thread to pass between and the spool. g

2. The combination with a loop taker, suitable for use in a shoe sewing machine, adapted to move in a circular path andhaving within it a housing for a mass of thread and a case for the thread mass, of retaining means comprising retractable fingers extending into the-said housing to engage the case and retain the same stationary during the movethe retaining means In testimony whereof I have signed my name to this specification.

WILFRID THOMAS ments of the loop taker and withdrawing V means arranged on theqloop taker body exterior to the housing for urging the said fingers away from the case at certain times f during the movements of the loop taker.

3. The combination with a loop taker suit- I able for use in a shoe sewing machine adapt ed to move in a circular path and having within it a housing for a mass of thread and a case for the thread mass, of retaining means of-the loop taker, and withdrawing means for said retaining means comprising a cam v member located on the outer face of the loop taker and arranged to engage said fingers during the movements of the loop taker.

4:. The combination witha loop taker suitf able for use in a shoe sewing machine adaptved to move in a circular path and comprising a tubular body having a loop taking beak.

at one end thereof and providing a housing for a thread case, retractable fingers arranged to engage the thread caseand retain the same stationary during the movements of the loop taker; and withdrawing means for said finranged to engage said fingers.

5. The combination with aloop taker suitable for use in a shoe sewing machine adapted to move in a circular path and comprising a tubular body having a loop taking beak at one end thereof and providing a housing for a thread case, retractable fingers arranged to engage the thread case and retain the same stationary during the movements of the loop taker, yielding means exterior to the housing for urging sald fingers into position to en-.

gage the thread case, and withdrawing,

- means for said fingers comprising an arcuatev Y lee,

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