US2158172A

US2158172A - Button sewing machine

Info

Publication number: US2158172A
Application number: US150138A
Authority: US
Inventors: Samuel W Avis
Original assignee: Reece Button Hole Machine Co
Current assignee: Reece Button Hole Machine Co
Priority date: 1936-02-24
Filing date: 1937-06-24
Publication date: 1939-05-16
Anticipated expiration: 1956-05-16

Description

y 6; 1939. s. w. AVIS 2,158,172

BUTTON SEWING MACHINE Oi'iginal Filed Dec. 24, 1936 7 Sheets-Sheet 1 ijluflaz ATTORNEYS May 16, 1939. 5 w v 2,158,172 7 BUTTON SEWING MACHINE 7 Original Filed Dec; 24, 1936 7 Sheets-Sheet 2 mvmoa ATTORN EYS s. w. AVIS BUTTON SEWING MACHINE May 16, 1939. 2,158,172

Original Filed Dc. 24, 1936 7 Sheets-Sheet 4 t ATTORN :YS

B; INVENSI'OR Q0. 'D Q May 16, 1939. v s', w. AVIS 7 2,158,172

BUTTON SEWING MACHINE Original Filed Dec. 24, 1936. 7 Sheets-Sheet 6 ATTORNEYS y s. w; AVIS 2,158,172

BUTTON SEWING MACHINE Original Filed Dec. 24, 1936 7 Shet's-Sheet 7 INVENTOR si uav ATTORNEYS Patented May 16, 1939 UNITED STATES PATENT OFFICE BUTTON SEWING MACHINE Original application December 24, 1936, Serial No. 117,550. Divided and this application June 24, 1937, Serial No. 150,138

3 Claims.

This invention relates to sewing machines, and especially, although not exclusively, to button sewing machines of the type shown and described in application Serial No. 117,550, filed December 24, 1936 (of which this case is a division), and having stitch-forming mechanism operating in a cycle to form a group of stitches of a predetermined number and character, said stitch-forming mechanism including a needle and cooperating loop-handling elements.

The invention has for its object to provide improved thread-handling mechanism for machines of this and similar types including means for withdrawing each needle loop, as it is released by movement of the latter, means for setting the stitches and for accurately measuring the thread for each stitch in accordance with the requirements, and means whereby, when the thread is severed at the completion of agroup of stitches, sufficient thread is drawn from the supply to insure the proper formation of the initial stitch of a succeeding group.

The foregoing and other'objects of the invention, together with means whereby the latter may be carried into effect, will best be understood from the following description of an illustrative embodiment thereof shown in the accompanying drawings. The particular mechanism described and shown has, however, been chosen for purposes of exemplification merely, as it will be obvious to those skilled in the art that the invention, as defined by the claims hereunto appended, may be otherwise embodied without departure from the spirit and scope thereof.

In said drawings:

Fig. 1 is a side elevation, partly broken away, of the complete machine.

Fig. 2 is a plan View, and

Fig. 3 a side elevation of the main cam.

Fig. 4 is a section on the line 4-4, Fig. 3.

Fig. 5 is a fragmentary plan View of the mechanism for producing the lateral movements of the needle.

Fig. 6 is a fragmentary plan view of a part of the looper operating mechanism.

Fig. '7 is a section taken substantially on the line 'il, Fig. 1.

Fig. 8 is a detail fragmentary plan view, partly in section, of portions of the tying-stitch-forming and thread-cutting mechanism.

Fig. 9 is a fragmentary sectional perspective view of a portion of the mechanism shown in Fig. 8.

the loop-handling elements, from the path of Fig. 10 is a detail section taken substantially on the line Ill-ll], Fig. 9.

Fig. 11 is a side elevation, Fig. 12 a plan view, and Fig. 13 a front elevation, all partly in section, of the thread take-up, pull-off, and tension mechanism.

Figs. 14 and 15 are fragmentary perspective views of parts of the same mechanism.

Figs. 16 to 22 are detail views, partly in front elevation and partly in section, illustrating the operation of the stitch-forming mechanism during the tying stitch-forming cycle.

The invention is herein illustrated as embodied in a button sewing machine of the general type disclosed and claimed in an application, Serial No. 60,616, filed January 24, 1936, by Franklin A. Reece. In order to make clear the purpose and operation of the mechanism to which the present invention relates, the general construction and operation of the machine of said application will be described.

Referring to Fig. 1, the frame or casing of the machine comprises a base or bed 10 and an overhanging head H supported therefrom by an upright housing portion 12 enclosing the principal parts of the operating and controlling devices. For convenience of assembly and repair said frame' or casing comprises two separable main sections A and A2 and several attached minor parts all of which collectively afford the necessary enclosures, supports, bearings, etc., for the various moving parts.

The bed 10 carries a Work or throat plate 13 upon which the fabric W to which the buttons are to be attached is supported and against which it is clamped by a presser foot 14 carrying a button clamp 15 for holding the individual buttons and positioning them for the operation of the sewing instrumentalities.

The main driving and controlling instrumentalities include a main power shaft 16 journalled in suitable bearings in the head H and to which power may be applied through a belt pulley ll; 'a vertical cam shaft 18 journalled in suitable bearings in the housing 12, driven through a worm 25 and worm gear 26 (see Fig. 5) from the main shaft 16, and provided with suitable cams for controlling the movements of the several instrumentalities; and a horizontal looper shaft 19 journalled in suitable bearings in the base 10. and operated and controlled from the cam shaft 78.

The stitch-forming instrumentalities include an eye-pointed needle carried by a needle bar 81 mounted for vertical or longitudinal reciproca tion in the head TI and a pair of

loopers

82 and 83 on a looper carrier 84 secured to the looper.

shaft I9 adjacent its forward end. Except as hereinafter mentioned, these instrumentalities 5 may be substantially as shown and described in the Dahl Patent No. 862,238, August 6, 1907, but, specifically, r as shown herein are substantially as more-fully shown and described inapplication Serial No. 64,693, filed February 19, 1936, by Joseph H. Pikul. The sewing thread if is supplied to the needle 80 from a suitable source, not shown, through suitably arranged guides on the head and needle bar andshowm'for example, at 86 and 81, under the controlof'threadhandling mechanism hereinafter described.

The needle bar 8| isilongitudinallywreciprocated by a crank pin 90 carried b'y' a'idisk a9 on the shaft I6 and connected by suitable linkage9l with a collar 92 on said needle bar, and-is guided adjacent its upper end in a bearing 93 which, as

- shown, -is==pivote'd: at 9d -to astud=95 swivelled in the head II. Adjacent its lower-end the-needle bar is-g-uidedinaa bearing-:96 similarly mounted,

"as showmat 91, on the front end of a' carrier 'member '98. The carrier -member =98 -is received in a groove in the top of a head l-flfi 'havi-nga shank-r trunnion I 01'- received i-n a socket 1 I 08 in the bottom-' wall ofi the' head I I ofthe machine,

Whereby said-P head I flfi -is pivoted for oscillation 30 about the-axis of-said= shank. 'Ihe'carr-ierWB -is oscillated latera1lyabout'the-axis of the pivot- I01 to cause the needlerito pass-alternately through different thread-receiving -holes 1 in :a button to *be attached '-by mechanism most clearly 'shown in Fig. "5. Said mechanism-comprises-a link I t3 -one end of whioh is pivotally connectedmt I I 4 wi-tl'r theoarr-ier 98. :"Ihe oppositeendhf thelink I F3 is provided 'with a :stud l2ll adzjustably re- I eeivd imanercuate: groove I2 I in' :one armvofia 40 =lever I22':secured to-aan uprightashafti I23 :journalled in a bearing I24 dependingf-rom the top -or thei-hea'd l I. fiAt-itswopposite'end the'llever- I22 "carries: ahpin I2 5 4 whichi engages iarzcami :groove t21 in the. .upperface ofzwmain cam: l29rufast: 011 e45 thevertical'cam shaft I8. tiniorder-tmavoidacon- -fusion, the: :cam groove 1 2 I E .isaonlynpartiallyz zinr dicate'dain Fig.1 5";bl1tifiS:'.G1e3,I1y:sh0Wn? inmfull' in E'F-ig. 2. a-With this constnuctionitawill beuseen 'xthatr rotation: iOfi-the' cam: I2 9\ .willzcause the. lever sthatthis-movementmvill be transmitted from: said lever to the carrier 98 throughtherlinlc I l3.

Hie! looperxshaftz l9 .-is :mounted at itS'TIBaIieIld zinaas sleeve I19 (see Fig.i6) zrotatablyzmounted ..55;in=a;suitable bearing in theframe. sAdjacentathe forwardeen'dcoftthersleeve I 'wtthezsha-ft 'I9i-has s-securedwtheretozaacollar' I89 :(seeealsorFignl) and rthe contiguousnends-r of saidzsleeve'; andzcollarnare suitably formed to::constitute:the:complementary a 60 -elements:.ofracouplingnor; clutch-zconnecting: the

usleevecand shaft; for :oscillation 'rinzzunison. At :=its.-rean end the sleeve. IIIQLEISEEfOIlT-lfid withsa-hea'd I8 Irhavingaartransversevborei182: in: which-sax stud 1831 isvrotatablynand slidab ly mounted. :The-stud ring-ink Iwhichz is aslidably received: a=:stud I 85 -secured witlrin and projectingislongitudinally from the *end: ofiaan rarml t86securedi to one--en'dof a (transverse; ro'ck shaftr t8? journalle'd '-in =a suitvo tableebearing in the frame. By this' construction I the shaft II 81. rand-:sleeve I I9, although disposed perpendicular to one another, are connectd=-for oscillation in unison. 'At its opposite endthe rock sshaft: I8'I has secured thereto a bifurcated arm :15 i88zbetweenr the biturcations of' Whichis-piv0ted at I89 the lower end of a link I90. The upper end of the link I90 is provided with a transverse stud I9I which is adjustably received in an armate groove I92 in one end of a lever I93 fulcrumed at its opposite end on a stud I 94 project- 5 ing inwardly from the side Wall of the housing I2. Intermediate its.endsr'the'lever I93 carries a pin I95 engaging a cam groove- I9I'formed in .the side or periphery of the main cam I29. The "groove I91 corresponds to the groove I27, that 'iS.. -I302-'S Y,TI3hef number and timing of the oscillations of the looper shaft I9 produced by the ,former -correspon :'I;.-to the number and timing fv the latera1:.oscillations of the needle produced 'bythelatter. Accordingly, the oscillations of theloopers:arezsynchronized with the lateral zoscillations' ofthe needle.

-'I-he==ma'in. cam. I29 makes one complete rotation,for-.a group of stitches the number of which depends upon the shape of the cam grooves I2'I ,arid 191. Referring to (FFig. 2,=.the."cam -'groove I2! is formed with zfiver' radially .ofiset -portions, adapted :to'zproduce five complete :lateral reciprocatrlonsmof: themeedle, i innsynchronism with 1 the -vertical reciprocationsithereofg-and with: a con- :centric cportionfr23l --duri-ng :which the needle-is .-.caused to make twocdescentsrthrough the same Lhole. uthe button in: zorderzto form wa lknot or :.-tying. stitch. \:-.Ihe.=groove% I91-.is correspondingly formed.touproducethe'requisite oscillatory-move- 90 -mentsaofrthei loopers-s92zandxs83 to causezthem to ecooperate :alternately *awith :the needle in the t-formation ofrlthezattachi-ng stitchesand includes a portion 213- .(Eigx3) soashapedzas'td cause one, zofssaid loopers-:to cooperate twice-invsuccession35 cWithzsaidrnedleWhBn. theglatter descends" twice tthnoughi thee samesholei :inathe: formation-10f the --tying s-stitch, :..as hereinafter further explained. :,.C msequently, :each fgI'OILpfiOf-E stitches will com- ,:-priseir=ten= attachingwstritchesnand :ai tying --sti-tch,44o thewwhoieg-roup requiring twelve'vertical'reciprorcations. of thezneedle.

The belt pulley TI (Fig. 1).:isloose:onthe-sha;ft J6 vandris Iadapted'toibe: clutched: thereto: by a combined clutch :andzstop mechanism whichiisgg; coperatedrbyrazstud 30 I .onithevmaimcam- I29 upon 1 the;completion.-ofra:rotation ofisaidwcamiandthe wconsequent 1 completion =-of a @-:group iof stitches. i-JDhis nstop '.-mechanism and? the means r for -con- --trolling thersame are not-:shownin detailF-hereingmo as z-they constituteno i-portion of f the invention :herei-n'claimed.

[Referring:particularly;t0:Figs. 16 to .--22,the loopers.- BZiand 83;-are-formed with thread engaging shoulders z andrareesecured-in-fixedrpositionaw on the looper carrier 84 whichra-lsocarries: a pair zen-loopspreadersai 23 a'nd/ 224 corresponding: re-

spectively to the loopersr82wande83. ;The-

loop spreaders

223 and 22 lt are-cpi'votallyrmounted in the carrier 84aby :means of shanks 225 rotatablyuuu mounted-cm said carrier aand-are normally'held with: their 'endsuolesely adjacent the ends of: the :.loopers -and.-in substantially the same vertical plane therewith, as shown in Figs. 17, .18 and 2l,.by .means. of .torsionsprings 226 interposedfl between said carrier.aridtail portions23ll of said .loop. spreaders,;the. positions of said loop spreaders under the influence of said springs being'determined by angularly adjustable stops 221. .Said 'loop:spreaders are moved out. of the latter posi-flZO tions to spreadthe threadi loops by means of a cam plate 228'v'vhichyduringthe attaching stitch- 'forming cycle, is'heId-statiOnary;but which is '-formed-with bevelled -edges' 229-"adapted, as'the looper carrier is oscillated, to engage the ta ilrm portion 230 of one or the other of the loop spreaders and move the same into loop spreading position as shown in Figs. 16, 19, 20 and 22.

The operation of the above mechanism in the formation of the attaching stitches is substantially as more fully described in the Dahl patent and the Pikul application, above referred to. As the needle descends alternately through two holes in a button, and rises, leaving behind it athread loop, the loopers and their respective coacting loop spreaders, 82, 223 and 83, 224, alternately enter said loops, spread the same, and position them for the passage of the needle therethroug h during its successive descents. At the completion of the group of attaching stitches, the needle is caused to descend twice through the same hole in the button, due to the concentric portion 23I of the cam groove I 21 during which the looper mechanism, together with certain associated parts about to be described, operates in such a manner as to form a tying stitch and sever the thread.

Referring to Fig. 7, the cam plate 228 is secured, as by riveting,,to a sleeve 232 mounted to turn on a reduced end portion 233 of the looper shaft 19, while the looper carrier 84 has a hub portion 234 clamped or otherwise secured to said reduced portion. The cam plate 228, while free to turn on the shaft, is held against movement longitudinally thereof, in one direction, by engagement of said cam plate with the looper carrier hub, and in the opposite direction by engagement of the end of the sleeve 232 with a shoulder 236 at the endof the reduced portion 233. Secured to the sleeve 232 is a gear segment 364 which meshes with a complementary gear segment 336 on a shaft 249 (see Fig. 8) journalled in the machine frame. Adjacent its rear end the shaft 249 has secured thereto a collar 385 (Figs. 8, 9 and 10) having an upstanding stud 385 which is embraced by the forked end 331 of a lever 380 having a stem 389 journalled in the bracket or frame member 390 in which the rear end of the shaft 249 is journalled. The opposite end of the lever 388 is connected by a link 39I with an arm 392 fixed toan upright shaft 252, likewise journalled in the frame member 390. Secured to the upper end of the shaft 252, as by a pin 253, is a head 254. The head 254 carries a pin 255 which engages a groove 251 (see also Fig. 4) formed in the bottom of the main cam I29.

The cam groove 251 (Fig. 4) is for the most part concentric but includes an operative portion 212 so arranged as to be engaged by the pin 255 when the pin I25 is in the concentric portion 23I of the groove I21. The form of the cam groove portion 212 is such as to cause two oscillations of the cam plate 228 during two stitch-forming cycles in the course of which the needle makes two descents through the same hole in the button, as above explained. The cam groove I91 (Fig. 3) is formed with portions 214 and 215, offset in the same manner as the portions producing the attaching-stitch-forming oscillations of the looper but to a lesser extent and of less angular length. The arrangement is such that the pin I95 engages the cam groove portions 214 and 215 when the pin I25 is in the concentric portion 23I of the groove I21 and when the pin 255 is in the operative portion 212 of the cam groove 251.

The operation of the mechanism above tiescribed in the formation of the tying'stitch is illustrated in Figs. 16 to 22. After the formation of the last loop of the group of attaching stitches, for example, the loop Zx formed by the descent of the needle through the hole 71.2, the needle again descends through the other hole, for example, the hole h shown at-the left in Figs. 16 and 1'7, and through said loop lac, while the latter is held by the looper 83 and loop spreader 224, and thereafter rises, leaving behind it a loop la as shown in Fig. 18. Simultaneously the looper carrier moves, first toward the right (Fig. 1'7) to cause the looper 83 and loop spreader 224 to release the loop Zr and cast the same about the needle, and then, under the influence of the cam groove portion 214 (Fig. 3) toward the left to cause said looper and loop spreader to enter 5 the loop la, as shown in Fig. 18. During the latter movement the cam plate 228, under the infiuence of the operative portion 212 (Fig. 4) of the cam groove 251, also moves toward the left, following the movement of the loop spreader 224, so that there is at this time no loop-spreading actuation of the latter, and its entry into the loop la with the looper 83 is facilitated. Thereafter, as the needle continues to rise, said operative cam groove portion 212 causes the cam plate 228 to be turned toward the right, thereby causing the loop spreader 224 to spread the loop lot, as shown in Fig. 19. The needle thereupon decends again through the same hole h and through the loop la, which is held open and in a position to receive it by the looper S3 and loop spreader 224, as shown in Fig. 20. The looper carrier 84 then moves toward the right, causing the looper 83 and loop spreader 224 to release the loop la and cast the same about the needle as above de-..3 scribed in connection with the loop lac and as shown in Fig. 1'7. The needle then rises, leaving behind it a loo-p Zb which is entered by the looper 83 and loop spreader 224, by reason of movement of the looper carrier toward the left Uri-r der the influence of the cam groove portion 215, as shown in Fig. 21, the cam plate 228 again partaking of this movement, as above described in connection with Fig. 18. The cam plate 228 thereupon again moves toward the right, spread-a ing the loop lb as shown in Fig. 22, whereupon mechanism forming no portion of the present invention and not shown herein operates to sever one leg of the loop lb, as shown in Fig. 22.

Referring to Figs. 11 to 15, the thread it, in its;

, passage from the source of supply to the guides 86, is engaged by a combined tension and pull-01f mechanism and a combined take-up and threadmeasuring mechanism, which mechanisms cooperate with the stitch-forming instrumentalitiesa-s above described in controlling the thread during the stitch-forming operations.

The tension and pull-off mechanism includes an upright lever 394 pivoted at 395 in the machine head and carrying above its pivot two tension de-:.;: vices 336, 391 of conventional form and each comprising a pair of discs pressed toward one another by a spring and between which discs the thread passes. The lower end of the lever 304 is connected by a link 390 with the head 399 of. a stud 400 swivelled in the upturned end 40 I of an arm 402 fast to the upper end of a short upright shaft 403 journalled in a frame member 404 depending from the top of the machine head 1!. Secured to the lower end of the shaft 403 is a two-armed lever, one arm 405 of which is connected by a spring 406 with a fixed part of the machine frame and the other arm 401 of which .is formed with a bifurcated end to receive a block 408 swivelled on a stud 405 carried by one arm 4! 0 7 '.of-:.assecondtwosarmed lever! secured to :-a second .uprightjshaftsfl l likewise jour-nalled in the frame .1member z404. :The other .arm -4i2 of said-last- .namedtwo-armed lever engages-at its end a cam 5 1M3 secured to the top of the main cam I29. The .end-.of the-arm-A I2 is held in engagement with the .periphery of the cam14l3 by the spring 555, and theeshape ofsaid cam M3 is such that, as the -.-mai-n cam-makes a complete rotation during the .formation of a groupof attaching and tying stitches, as above described, the lever 394 is gradually moved from the position shown in .broken lines in Fig. 1l.-into the position shown -in:f ull lines-therein, thereby gradually drawing from .thesupply. a; length of thread in excess of ..that required for the stitch-forming operations. ...'I'he partsare shown in Figs..12.and 15, and in full elines in: Fig. 11,.in the positions assumed thereby -at;the completion of a group of stitches and the severing of the thread. Immediately upon the -.:beginning of the next group of stitches, the cam m4 t3 permits the spring 465 to move the arm 394 .into" the position shown in broken lines in Fig. 11, .thereby: releasing to the needle the excess length ==of-thread which has been gradually drawn. from .thesupply during the formation of the first stitch group; so that the needle, in its first descent in the .second'stitch-group-forming cycle is insured an adequate supply of thread for the formation ,of 30 the first. stitch.

The. take-up and thread-measuring mechanism includes=a,three-armed lever pivoted on a pintle 1H4 mounted in-and extending across a casing 4 I 5 securedto the top of the head ll, said lever hav- 5 ing an .upright'arm 4 l 6 extending through an .opening 4H in the top of said casing, a second :arm'4l8connected by a spring 4l9 with the wall ;of-said casing, and-a third arm 420 engaged by the :upper endof a, plunger 42l slidably mounted in. the top of the head H and engaging at its lower endla cam-422 .on the main power or needle shaft 16. The spring 4l9 acts to hold plunger 42I in engagement with the periphery of the cam 422, sand the shape of the latter is such that during 5- eachzvertical reciprocation of the needle the. arm a4iiiisswung from the position shown in full lines irinzFig. 11 to the position shown in broken lines tthereinzas the needle descends and in the opposite direction asthe needle rises. The arm M6 11s provided-with a series of parallel, laterally ,pro-

:jecting studs 423 having perforations 424 through which the. thread passes. Adjacent the path of movement of the. arm M6 is a fixed arm 425 like- -wiserprovided-with aseries of parallel, laterally 'EBilDI'OjGCtiiIIgTStHdS 42B so arrangedthat, as the :armMHi-ismoved .into the position shown in Fig.

14 and in full lines in Fig 11, the studs 423 pass :betweemthe'studs' 426, so that the latter deflect :t'hethread'outzof the straight lineconnecting the -1perforationsa424, thereby drawing through the 'tensionmechanism a measured length of thread :suit'ableforthe formation of a stitch. Inorder ,rthat :thelength of thread someasured may be -variedin accordance'with the size of the button, :the'spacing of the-holes therein, the thickness :zofithework, and the length of the shank or neck ;.'desired,'the arm 425 is adjustably mounted with -respectto' the limit of rearward movement of the zarm-4l6 soas to vary the extent of the deflection r70 offthethread. --As shown, the arm-425 is pivotally -.=mounted"on the pintle M4 and is formed with an extension 421 :provided with anzopening to re- :ceivethe end .ofa spring pressed plunger 428. "The plunger 428 is mounted in a barrel 429 mov- 'i5e'ableineanarcuateeslot430.'in,the wall of the -casing 4l5 and;.carried. .by .a plate 43I likewise .pivotallymounted-on the. pintle4l4 but adapted to be secured. inadjusted position by a clamp 432 operatedby awscrew-433 extending through the Wall of the casing .415. By withdrawing the plunger-428, the.:arm 425 can be released and swung out of the. way for convenience in threadingthestuds .423. .Byreleasing the clamp 432 the arm 425 and plate.43l can be swung as a unit about the axis .of the .pintle4l4, thereby varying theiposition of saidarm with respect to the exvtremeposition .of thearm.4l6 shown in full lines in Fig. .11. The .measured .amount of thread .drawnofi in :each stitch-forming operation can .,be. roughly varied. by passing the thread through the perforations..424. of va greater or less number ofstuds.423, thereby varying the number of defiections causedbythestuds 426, and a finer ad- -justment effected. by adjusting the plate 43l as -above described.

Mounted onthe pintle M4 at the exterior of the casing M is an arm 434 having an arcuate slot 435 to receivea clamp screw436 threaded into the casing wall, wherebysaidarm may be adjustably fixed in position. The arm 434 is formed .with an angular end portion431 adapted, as the arm 14|6 is moved into .thef'orward position shown in brokenlines in.Fig. 11, to engage the thread between the two outermost studs 423 and deflect the same.

In operatiomas the needle descends, the arm 4H6 moves forwardlyv fromthe position shown in full-linesinFig. l1 towardthe position shown in broken lines therein, thereby paying out the thread as.required'byathe.descentof the needle. When.theneedleapproaches the lower limit of its movementand has passed through a loop held by .a looper :andits-cooperating loop spreader and then released thereby, the thread is engaged by theend 431'of the arm434 and deflected, consequently drawingthe supply .backand thereby withdrawing the loop from the looper and loop spreader, asshown in Fig. 17. As the arm. 4H5 moves rearwardly .during .the ascent of the needle, the thread is released by the arm 434, therei by insuring anadequate amount of thread for the next succeeding loop to be taken by the looper and loop spreader as shown in Fig. 18. As the needle approaches the upper limit of its movement, the thread between the studs 423 is engaged by the'studs426; thereby deflecting the same and exerting a pull thereon between the tension devices andthe work which actsto set the stitch-.andalso todraw through the tension devices'a-measured length'ofthread for the next stitch.

I claim:

1. In :a sewing machine, the combination with stitch-forming elements and operating mechanism therefor having a cycle of operation'to I cause said elements to form a group ofstitches, of a tension device through which thethread passes'from the source of supply to said stitch- .forming elements, and means-formoving said ing stitches, of a take-up movable concurrently with said needle to release thread to the latter during its penetrating stroke and to take up thread during its withdrawal stroke, and means coacting with said take-up to withdraw a loop released by said looper elements from the path of movement thereof as the needle approaches the limit of its penetrating stroke.

3. In a sewing machine, the combination with stitch-forming elements including a needle and operating mechanism therefor including means for reciprocating said needle to cause the same to penetrate and withdraw from the work, said operating mechanism having a cycle of operation to cause said stitch-forming elements to form a group of stitches, of a tension device through which the thread passes from the source of supply to said needle; means for moving said tension device in a direction to draw thread from the source of supply during said cycle and in a direction to release thread to the needle at the beginning of the next' cycle, a take-up movable concurrently with said needle to release thread to the latter during its penetrating stroke and to take up thread during its withdrawal stroke, said take-up having a plurality of thread guides between which the thread is normally led in a straight path in its passage from the tension device to the needle, and one or more fixed members engaged by the thread between said guides to deflect the same from said straight path as the needle approaches the limit ofits withdrawal stroke.

SAMUEL W. AVIS.