US1291335A - Thread-cutting mechanism for sewing-machines. - Google Patents

Description

'APPLICATlOfi FILED APR. 18. I918.

I Patented Jan. I, 1919.

.l V! W m H W .L 0 J m W T n m M k m w 6 7 S xv V. v

. 4 EU 2 W :1 I B ymja A. R. W000. THREAD CUTTING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED APR.1B, 1 9L8.

1,291,335. fatenied 1919.

2 sums-snarle- INVENTOR leaflet in order than.

sA'IP irnnfr onisic ALFRED It. W001i, BRIDGEPORT, CONNECTICUT, ASSIGNOB. TO THE SINGER MANU FACTURING *QGMPANY, A CORPORATION OF NEW J ERSEY.

I THREAKl-GUTTING MECHANISM FOR SEWING-MACHINES.

' Application filed April 18,

To alt whom it may, concern lie it l-tnown that l', Amman ll. Woo na citizen, of the Unit-ed States, residing at lira port, in the county of Fairficld and State of Qonnecticut have invented certain new and useful improvements in Thr nd- Uutting h'lecha'nisnis for Sewing-Machines, of which. the following is a specification, rot orence being had therein to the aecon panying drawings.

This invention relates to thread-eutting ni tihanisni for sewing machines, more parti iiarly of the buttonhole type employing a rccign'oceting needle and lower thread-hen can; inipienicnts mounted in a rotary turret nnd cooperating therewith to form a group of overseaining stitches. An object of the invention is to provide an improved mechanism for cutting the needle-thread in a machine of the class described at a point below the worli' and close to the under side of the the cut end of needlethi'cad, leading to the iast stitch will be short and so that a relatively iong length of thread will he left hangi from the eye of the necdie. to sis-unis the starting of the next stitching operation.

A. tort-her object of the invention is to pro vicl'e a. slu'eadcuttinn; mechanism paiticulariy adapted for embodiment in machine making the eyic-ot' stitch disclosed in the Un ted States Patent to E. E. Allen No.

-- idniihfhtii, defied June 18, 1912, and which will not interfere with the movements of the necessary thread-handling iinplemen$ or .hiopers close to the under surface oi the vvorlc l titill further, the invention has for an objest to provide a threachcutting mechanism which will sever the thread with certainty even though the cutting blade should become slightly dulled through long; continued use.

li urther objects of the invention will appear from the foilowing description and claims.

iough the invention is sumeptibleot: einhoriunent in sewing machines of various types have chosen to illustrate it aseinhodied in the buttcnhole sewing machine" oi. lcsed in the application of E, B. Allen, Serial No. 179,139, filed July 7, 1917; said machine being fitted with stitch-formin mechanism of the im'roved type disclosed in the application of Allen and H. Cl Faulkner, Seriai No. 222,071, filed March 13,

Specification of Letters Patent.

'atented Jain tat, 1919.

1918. Serial No. 229,237.

1918. Buttonhole sewing machines of the types disclosed in the said applications are commonly provided with buttonhole cutting mechanism which operates to cut the buttonhole either before or after the stitching operation, the cutting being accomplished when the stitch-forming iiiccllanisni and the worle holder are dilferently positioned relatively to each other than when the machine is stitching.

When the machine has been brought to rest at the end of a hiittonholc-producing cycle, the stitclnforniing mechanism -and work-holder are in buttonhole cutting position and when theniachinc is again started the Work is clamped in a new position. If the machine is one that cuts the butt-onhole before stitchii'ig, the buttonholc-ci tter next gnnes into action to cut the buttbnhole-slit after which the Work-holder and stitch-tonning mechanism partake of a relative movement to carry the parts to stitching position. The stitch-forming mechanism is then started an lfduring a further relative stitch-positioning movement of said stitch-forming 80 mechanism and work-holder, the werseaniing stitches are placed around the buttonholet if the niachine'is adapted to sew series of radial stitches at the end of the buttonhole, the stitch-forming mechanism is given a partial rotati 11 after the first side of the buttonhole in s en stitched to position stitches iadially around the end. of the huttonhole. After the second or return side of the huttcnhole has been stitched, the stitchforming mechanism ,is Stopped and the I stitch-forming mechanism and work-holder have a further relative movement to bring the parts to huttonhole cutting position again whereupon the machine is brought to rest. l adjustment 0 the time of operation of the stitch-forming mechanism, buttonholes of various lengths may be stitched; the stitch-forming mechanism starting earlier and finishing later to stitch a longer buttonhole. The total relative travel of the stitcl1-f rrning mechanism and work-holder is fixed for all. lengtl s oi huttonholcs produced by the machine and slightly exceeds the longest bnttonhole which the machine is designed produce. When the machine is brought to rest it has heretofore been customary to c it the needle-thread by hand at the upper side of.

the Wonk; the thread extending work, around :1 lower thread-handling in plomnt and b ick to the lust stitch. 'Tho cutting or the i'ioodio-t-lnezu'l above the Work therefore necessitates n considerable waste of thread since :1 relatively long thread-end is left hanging from the nndei side of the Work after it is ICIBOVLKlflOH'I tho machine.

through ihe' Iwioroovor there is danger that the needle,

may become nnthi'eaded due to tho drawing back of the short thread-end hanging from the lnGGLllQ-QYP. it has also been proposed, in a machine of the presPni: character, to out the thread of tho last noodle-loop below the work but, in the latter case, the limb of tho needle-loop leading in the needle has been,

out and co'i'isequontly a long and of thread has hoon loft, hanging from'tlic work and a short and has been left hanging from the noodle-eye.

The fox-{going difficulties auto overcome and the ohjocts of the invention um attained by tho cinployn'mnt of a specially formed tlii'ond'iciiil'iiig blade which is lYlOiHJ-TfllP011 handling; instz'izn'iontalilin which eoiipornlo with the needle. in tliopi'oim'rvd enil odi-- montoi the invvniioin thellnvml-cuiting lihido is ankle-shaped and is :l'oimvd at- 51 short dislunvu hack of itstip-end with :i redm'od noel: iilh'n'dingr ll i-onirwiutdly directed and 'shni'pnnvd mailing edge. 'Thohlnde is pivoi'nlly mounted at its-shimivi nd upon a nmwllv-guidv him-hut, which, in turn, is rigidly ansiuinml in :i 'po iit rising fiom the inn-vi. 'lhv i-ntiiai hizado;i:-; suhsinnt'inlly fiat and is no iiisposvd us toppomio in a substnn.

are "formed iniogrz'iilly with thoslinnk-cnd oftho viillor-hh do undnmsh with uisogn onigal implomon-l's for oRvillntoi'y movomonii'ohi.

lively to said pin. Th4: said iillpi'nni-pin can-non a crank member which is noted npon 'lhzougli Silli'il-lilo minim-lions \Ylllih'? slop-motion which conii'olsiho period of opoz'ntion'oi lho rsliii'h-foi-ming nwvlihn'isni, am lltflllfitil!iQVQ! niounimlnpon iliiQiiiiM'liiiiii fi'znnoto swing llUl'i'li-(lllliilihi first unused lo ongngo and shift, the lover mounted on hnitonhole, the turret i5 not. in position for the spying-actuated lever momted thereon to be engaged by thomsiuator-lovor.- Assoon as the turret has been rotated the us'g a'l 180 in stitching around the end of the bi1ttonhole, the, spring-zict-imted lever is carried into operative position relatively to the actu :itordovciand is in position to lie shiftod hythe actuator-lover whonovei' the stop-mm iiion is tripped.

In the :iccompanying drnwings, I fi gnro il.

is an nssomljilod. perspective view of the parts of the, huhtonhole sowing niavhino irelnting $10 the present invention. Fig. 2 IS a your poi'spmtliivo View of tho liaise-portion of the machine showing, the stop-mvvhnnism and the lhroiul-cuttor actuating connections. Fig. 3 is a poi's 'ieoiivo View of the turret for the lower thrond-lmndlingimplements showcutting and slitvliing machine (llSUlUHlll in the application oi E. B. Allen :iho'i'o iol vl'l'fll to. The 1nnchinwfrnniucomprises a hollow llKflilHgIllliU' lmsvfil sustaining tho niuuulnx d 2 and overhanging l'nuu kothrni 3 timinating in the, hollon head 4 in winch the nevdlvhal 5 is journnlod foi-ii'egipiot-alion. At its tho lllll'tl; in opposition :fo'its spring,'thorohy :i'wd lover lowiihdmw tho vntmi'dilade to inopm'nin'iposition and in While btiiching down the first gaido dithewhoRitclnforming A and holds it n s 'ii'eadwonditzon in t low'nif. "th road 3 common to ingiohins' (if 'thIS typg 1 Cooperating w th theiphreaddl loope which proje tho cross-11in oi" the nedlo on its"(lonlhk-iihili cent.

(:lss itsloop throngli an owrdg I im-dle-loop, is" a loop-retainer ll jllOlll'llfBd on f-i cai-i-wr-lm'e E; a sevond loop-retainerhi8 mounted upon :i mii'i'ior-loi'oi' '19 luhrriimnd to turn'lupon l tho cross-phi ill. Tho secondiretainer"18 seizes 2i depth-stitch nuedlaf-lpop from the over-edge descent.

non-threaded looper and holds it in spread condition in the. path of the needle in its The retainer levers are oscillated simultaneously in opposite directions by means of link connections 15, v19 with a cross-head 19 formed at the upper end of the usual rising and falling rod 19" common to mechanisms of the present type. The retainers 14 and 18 operate in substantially parallel paths close to the under surface of the work and below the usual throatplate or button 20 which is fixed to the post teeth 25 integral-therewith and is fulcrumed to the nedle-guide bracket 26 .by means of the screw-pin 27 the bracket 26 being fixed to the top of the post 21 and formed at its free end with the needle-guiding plate 28 which insures the positioning of the needle forwardly of the paths of movement (if the threaded and non-threaded loopers so that.

it will not be struckby said loopers While the latter are seizing needle-loops. Thecutting blade is so fulcrumed. that the path of movement of its freeend is close to the path of movement of the retainer 18 for the depth-stitch needledoop; the beaks or tipends of the retainer 18 and thread-cutter y direction.

22 being pointed in substantially the same Meshing with the gear-teeth 2515 a segment gear 29 fixed to the cross-pin 16'to one end of Which is fixed a crank-arm 30 slotted gat 31'to embrace a pin 32 fixed to the up- ,avardlv extending arm 33 of a three-armed lever fulcrumed at the junctureot the arms to the post 17 by means of the screw 34.

The depending arm 35 of the three-armedlever is formed with a lateral extension 36 Y which, when the turret is rotated to the position shown in Fig. 3, is in position to be struck by the actuator-lever 37. Stops 38,

for the lever-arms 33 and 35 determine "the extreme positions of the cutter-blade 22.

A spring 39 is fixed at its upp'eFend to one of the posts 17 and at its lower end to tliit.

bracket 41 screwed to an inside wall of the base 1 and formed with anapertured guidecar 42 for the forward end ofthe slide-rod .43 the rearward endof which is connected to the crank-arm 44 fixed to the rock-shaft l5 journaled in'the bracket 46 fixed to'the machine frame. A spring a? surrounding ear 42 and a collar 48 on said slide-rod,

'urges the latter toward retracted position.

T he actuator-lever 37 is also provided with a spring 49 which yieldingly maintains said lever in contact with the front end of the slide-rod 43.

The rock-shaft 45 carries another crankarm 49 which extends across the path of vertical movement of the lateral pin 50 fixed to the usual downwardly spring-pressed slide-block 51 mounted at the lower end of the stop-motion lever 52 which is fulerumed at 53 .to the machine frame. As stop-motions of the ty e herein referred to are well known a speci 0 description thereof is thought to be unnecessary. These stopmotions commonly employ a clutch ring 54 which is fulcrumed at 55 to the driven mem-" ber of the clutch and is formed with an outwardly inclined surface portion 56 leading to a stop-notch 57. When the stop-motion lever 52 is tripped to stopthe machine the stop-tooth 58 is shifted inwardly to a position wherein it will be lifted in opposition to the Spring 51 by the eccentric surface 56 of the clutcl-i ring. -When so lifted, the pin 50 will lift the crank-arm 49 thereby shifting the slide-rod 43 in opposition to its springer? and causing the actuator-lever 37 to deflect the lateralr rojection. -36 of the three-armed. cutter-con rolling (lever mounted on the turret. The cutter blade will thus be projected into the last needle-loop'l which is held by the retainer 18, as shown 1n Fig. 4, the 100 being drawn up snugly about the reduced neck of the cutter by the usual takeu mechanism before the machine comes to rest. When the tooth 58 naps into the stopnotch 57, the pressure of the slide-rod 43 upon the actuatordever 37 will be relieved and, as a result, the spring 39 will act upon the arm 400i the three-sinned lever to cause the withdrawal of the cutter-blade 22 from full to dotted line position,-' Fig. 4, to effeet the serverancefiflthat of the needle-loop which-slead's 'tofthelast stitch.

It will be readily appreciated that, by

virtue of the foregoing; construction, the

cutter 22 cannot glanoeb and fail to sever the needle-loop even though the cutting ed ge 24 should become slightly dulled through long continued use. v

- The machine i fitted with the usual mechanism for turnlng'the needle-bar 5 and tarret ll -in fiacing the radial stitches around the end of a buttonhole and for'reversely turning these parts to initial position after the buttonhole hasbeen stitched or before the next stitching operatipn.

The vertical shaft" 59 is formed at its its op osite ends with crank-arms 60 and 61 of su stantially the ame length and connected by means of links 62 and 63, respectively, with similar sector-gear levers (lat and 65,

roeating needle and c i meshing with pinionsGfi and 67 which transniit turning movements to the needle-bar and turret, respectively, in the usual manner. The crank-arn'i 61 formed with a follower (38 which enters the cam-groove 69 in the usual teed-wheel 70. l

oi the well known type including" lower and upper elam 'nng members 71 and 7]. partaking of longu udlnal and lateral, components of motion through suitable connections with the feedwheel.

- I lathe modification of theinvention shown .in' l i'n's. 5 and (l the ledger-blade 72 formed with an inclined and Sharp cutting edge73 IS let Into the rih'Tlat the turret; said llireaddnuulling implements bo inn mounted on said turret for cooperation o with} said needle and including a loop-rein I-l tainerfulcrinnedto turn upon and relatively to said rock-shaft. a thread-cutter mounted [,on said turret.actuatingconnections between said roclosha ft and thread-mittenand means for actuat ng said rock-shaft at tliee-nd of the stitching operation.

.2. In a sewing machine, in combination, stitch lul'llllllgj lllttfllzllllslln including a reciprecating needle and cooperating threadhandling implements, lneann ineluding a "1oia'ry turret tor tl ling said stit'elrformn'igmechanism in stitehing around the end of a' nnplehuttonhole eaid "thread --handling ment's be ng mounted on sait'l tu'rretand in eluding a loop -retainer having afbealnfon seizlng a, needle-loop and detamiiigitforl subsequent entry by said needle,-- a threadcutting implement mounted on said turret, u1ea-ns for advancing said cutting implement direction of loop-seizing movement of Said detainer to insert it into the last 3 the exposed face HIS set forth the-nature of the inmachine, in coi'uhin'a tion,

needle-hoop held by said detainer, and

means for ret'acting said thread-cutter to cause it to sever the needle-thread.

3. In a sewing n nichlne in combination, StIlClbfOlll'llng mechanism, means including a rotaryturret for turning said StltClkfOlll'h ing mechanisn'i in stitching around the end of a buttonho-le, a cuttenhlade detachabl y t'ulcrumed on Said turret and having inte grally formed geai teeth, and a segment aet'uatoiwgear' mounted on said turret and meshing with said gear-teeth.

-.i:. In a huttonhole sewing machiniaun combination, stitch-forming mechanism in cllu'ling a reciprocaiting needle, and complenient-al' loop'takingr means rotary supporting means; t'l'ierefor including aturret sustaining said loe-p-tali'ingr means, a needle- ,guidecarried by said turret, and a threaldpivot-ally mounted I on sa d cutter blade neialle-guide.

5. In a sewing machine, in combination,

stitclefoi'niing mechanism, rotar) supporting"mans therefor including a turret, a thread-clitting blademounted on said turret' arul formert with a forwardly directed point and arearwardly directed and sharp enedcutting edge, andii'ieans for advancing and retracting ,iiilthlllldii-d Clllitlllg blade to eause'tlie latter to first: enter the needle-loop and to subseq'iu-zntly sever one lin'ih thereof.

' (i. ln a sewing machine, in combination, stitch-forming iilechanisin, rotary supportetop-motion for controlling the period of action ofthe stitclpforming-Inecl1anisn'1, a

thread eutr'er mounted on said turret and tlrrezul-taztter' actuating ineans connected to said stopimotion' for causing the thread-cub ter to first enterandsubsequentlydraw back upon and sever the la stneedledoop.

a. In a eewing n1aeh1ne,'inconibinatlon,

stitch-forming meehanisni,' rotary supp0rting n'iea'ns thereforincluding aturret, a

stop-motionforeontrol-ling 'the period of ac. tion ofthe h-fornnng mechanism, said i stop-nuition' neludingga Spr ng-pressed stopplug tooth and a dri ven element formed with a stop-notch, a thread-cutter niountedon said turret, r and thread-cutter;- actuat ng means yconnee'ted to axial Stopping tooth for caus-' in mg" the thread-cutter to ifirst; enter and then d aw back upon; and sevfer the. last needle-' loop.

In testimony where' fl h v ig my n'ameto this speeifie atigm. v i @ALEREB REX- 00D.

ing InCilllSl-llGl'G fOI including a turret, a

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