US1346814A - Thread-severing mechanism for sewing-machines - Google Patents

Description

A. F FIFIELD. I THREAD SEVERING MECHANISM FOR SEWING MACHINES.

Patented July 20, 1920 5 SHEEIa-SHEEI l APPLICATION FILED SEPT- 23, 1916. 7 1,346,814.

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A TTOHI VEV A. F. FIFIELD. THREAD SEVERING MECHANISM FOR SEWING MACHINES. 1,346,814;

A. F. FIFIE LD. .THREAD SEVERINGMECI IANISM FOR SEWING/MACHINES.

APPLICATION FILED SEPT. 23, 19i6l 1,346,814. Patented July 20, 1920.

5 SHEElS-SHEEI 3- ATTORNEY A. F. FIFIELD. THREAD SEVERING MECHANISM FOR SEWING MACHINES.

I APPLICATION man SEPT. 23, 1916. 1 ,3 46,8 1 4, Patented July 20, 1920.

I j I s saws-sum 4.

TTOR/VEY 1 A. F.- FIFIELD. THREAD SEVERING MECHANISM FOR SEWING MACHINES.

Patented July 20, 1920.

, v APPLICATION FILED SEPT- 23, 1916.- 1,346,814.

A TTOR/VEY .UNIT-ED STATES PATENT critics)" ALBERT F. FIFIEL'D, 0E NEWARK, nEw JEEsE assisnon To THE SINGER MANU- *FACIUBING COMPANY, A CORPORATION on NEW JERSEY.

THREADPsEvE ING MECHANISM FOR SEWING-MACH NES.

Specification of Letters Patent.

' Patented July 2o, i920.

Application filed September 23,1916. Serial No. 121,705.

To all whom it may concern: a

Be it known that I, ALBERT F. FIE1E'L'I),'a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have-invented certainnew and useful Improvements in Thread-Severing Mechanisms for Sewing-Machines, of which the following is a specification, reference being had: :therein to the accompanying drawings. e

This/invention relates to improvements in sewing machines, particularly of the type embodying an automatic mechanism acting to stop the machine at the completion of'a predetermined number of stitches. Ma-

7 chines of this type are commonly used for may present a finished appearance whenit is sewingon buttons, stitching buttonholes,

bar-tacking, &c., and inorder thatthe work removed from themachine 'itis desirable to provide mechanism for severing thestitch 'ing threador threads close to the under sun face of he work atthe completion of. a

stitching operation To prevent unthreading of the needle and insure? the certain concatenation of the stitching thread'or threads when the ma-' chine is restarted, it is customary to provide an 'implem'ent'ior rece ving and detainlng the last needle-loop shed from" the looptaker so that the take-up, in completing its last up'stroke, may pull additional thread from-the supply and thus provide a length of needle-thread sufiicient for thebeginning of the next stitching operation. It also customary to provide a thread-gripping device whichacts to' grip the free end 'of the V needle-thread drawn down by the loop-taker when the machine is restarted, in orde'r'that the beginning endojf the needle-thread may be located at the under sideof theworkj It" is further customary in lock stitch machines ofthe' above type to provide an implement for pulling off a length of bobbin-thread 45 a order thatthe'cut end of the threadissuing prior to the, thread-severing operation in from the begin-may be g enou h to be cau ht and drawn up to the work by the first needle-loop cast about the bobbin. The

path of movement andtime of operation of 1 each of the various implements must he accurately controlled andfor this reason it has heretofore been theypractice tomount and operate ithese implements independentlyijof t dby a slotted camrplate secured actuator-bar above referred-t0; r.

U l c l V i each other, thus necessltatmg a more or less sequently nip the-beginning end of the needle'thread.

Another object of the inventionis to pros vide a lock-stitch machine with a simplified r threadsevering mechanism in which 'a single implement is adapted to. detain the last needle-loop, to pull off bobbin-thread, and to nip the free end ofthe needle-thread when the machine is'restarted.

'-A further object of the invention is to prot v1de a machine withthread-cutting mechanism including a single implement adapted to perform; any two of the three above mentioned functions; I

iFurther'objects of the invention ap- 1 pear from the following description and claims.

The present improvement, in its preferred embodiment, is shown applied to a lookstitch machine-of the well known type dis- I closed in the United States patent to J. J.

Sullivan, No. 777 ,564, of December 13, 1904,

to which reference may be made for details of the present machine not specifically referred to herein and in which the patterncamand stop-motion lever are adapted to impart :the usual plural-stage longitudinal movement to i an actuator-bar extending lengthwise ofand beneath the bed-plateof vthe machine. In the present ll'lStZtTlCBwZLl'l implement. or finger performing the func-" tions of'detaining and spreading-the needleloop, pulling ofPbobbin-thread, and subse: quently nipping the free end of the needlethread, is pivotally mounted on the under side of the thi'oatqolate adjacent the needleaperture for movementina plane atright angles to theneedle-path. This finger is, at V certain times, moved forward and backward across the needlepath by'a bellcrank-lever a fulcrumed beneath the Zbed-pla'te andj actuto the The Tthreadsevering devicecomprises a j stationary ledger-blade,secured tothe under side of the throat plate adjacent the needle 7 aperture, and a movable blade which is pivotally mounted on the throat-plate in cooperative relation with the ledger-blade,

and which has a lost-motion connection with the actuator-bar. Just prior to the stopping of the machine the actuator-bar receives the first stage of its movement to advance the finger to loop-detaining position and upon the stopping of the machine the overthrow of the main-shaft gives 'the well known second-stage movement to the actuator-bar which in the present instance causes the cutting blade to quickly enter the spread needle-thread loop and sever one limb thereof together with the bobbinthread. When the machine is restarted the detaining finger is returned toward its initial position and duringits movement passes backwardly across the needle-aperture in the throat-plate, carryingthe free end of the needle-thread loop and nipping the same againsta spring-plate mounted upon the under side of the throat plate; After the first few stitches have been formed a further movement of the detaining finger releases the needle-thread.

In the drawings, Figure lis a rear side" elevation, partly'in section, of a sewing machine embodylng the presentimprovements.

Fig. 2 is a bottom plan View of' the ma-' chine. Fig. 3 is a rear end elevation. Fig. 4 is a bottom plan view of the thr0at-plate of themachine together with the operative parts mounted thereon. Fig. 5 is section along the line 55, Fig. 4, the parts being upside down. -Fig. 6 is a similar section along the line 66, Fig.4. Figs. 7 to 12 inclusive are perspective views showing the relative positions of the operative parts beneath the throat-plate during successive arm 2* in which is journaled the main- ,shaft 3 carrying the tight and loose pulleys 4 and 5." Connected to the main-shaft through the link Gis the needle-bar -7 car .ryi'ng an eye-pointedf'needl e 8 cooperating with a loop-taking implement which, in the present instance, is illustrated in the form of a shuttle9'carrying a bobbin 10 about i which the needle threadl0ops are'cas't du'r e ingthe production of a series of lock stitches. The shuttle 9- is oscillated in a manner well known through the usual connections with the main-shaft '3, comprising the crank 11, pitman 12,:rock-lever 13 and shuttle' drivi'ng shaft 14. QThemain-shaft 3 also carries the usual take-up actuating cam 14 which vibrates the take-up 'lever'14 in an old and well known manner. The machine V is equipped with a: commonl'form of work-holder 15, to 'which lateral jogging movements are imparted by the usual connections with the pattern-cam 16 which is mounted 'on a cross. shaft 17 carrying a worm-wheel 18 meshing with the worm 19 on the main-shaft 3,all of which structure is fully disclosed in the Sullivan patent above referred to.

which is journaled the cylindrical plug 21 whose outer end is slotted to receive the usual vibratory stop-lever 22 which is pivotally'connected to the plug 21 by a pin 23, and which carries atits upper end the usual spring-pressed plunger rod 24 whose wedgeshaped upper end 25 is adapted for engagement with the well known stopping cam 26, into operative relation with which it is non mally pressed by suitable means such as the spring 27. The stop-lever 22 is yieldingly confined against one of the spaced flanges 28'of the bracket 20 by means of the transverse plunger-rod 29 mounted in the socketed' bearing boss 30in which is confinedthe buffer-spring 31. The stop-lever carries the usual belt-shipper 32.

The rearward face of the stop-lever 22 is formed with a groove 33 which is entered by. the hooked outer extremity of the usual latch-lever 34 pivoted upon the fulcrumscrew 35' and having a forwardly extending arm 36 whose extremity. is normally forced by a coiled spring 37 into the path of circular movement ofthe tripping lug 38 secured within the inner recessed face of the camwheel'16. In practice this tripping lug is so v arranged that the latch-lever 34 is tripped torelease thestop-lever 22 as the "needle completes its descentfor the final'tying stitch succeeding each group of fasteningstitches. The usual starting lever 39 is provided for tilting thestop-lever to disengage the plunger from the stopping cam and shift the belt onto thetight pulley 4. I

"The-single implement which serves to detain andv spread thelast needle-loop, to pull off the-bobbin thread, and to subsequently nip the beginning, end of the needle-thread, :is inthe form of afinger 40 and: is pivotally mounted between its. ends on the under side of the throat-plate 41 by means of the verti pally disposed screw-pin 42. The finger 40 :is. formed with a reduced shank. 43, Fig. 6',

terminating in athickened head 44 which is extended laterally in one direction to form two 'beaks' 45 and 46 defining between them aloop receiving throat 47. The head 44 is provided at' a point opposite the throat47 with a V-shaped needle-thread receiving the slot 60 by a nut 62, enters thecam-slot' caught between notch 48. The sidepf the head 44 adjacent the throat-plate" is flattened to form a thread-nipping surface 49, Figs. 5. and 6, which is spaced from areduced portion of the-under surface of thethroat-plate and is adapted to cooperatewith a complementary thread-nipping surface disposed at the under side ofthethroat-plate and preferably in a substantiallyhorizontal plane. In

practice, this nipping surface may' conveniently be provided at'the free end of the flat spring 51 which is fitted in a recess 52 in the under side of thethro-at-plate and held in position by the screw 53. In the present instance, the free'end of the spring 51 may yield somewhat when the needle-thread is the nipping surfaces 49 and50.

. Mounted on the finger 40, at the extremity opposite the head 4P1, is a roller-stud 54 which is embracedby the forked extremity 55 of onearm 5.6 of a bellcrank-lever culcrunied at 57 to the fixed plate 58 secured to the under side of the bed-plate 1. The other arm-59 of the bellcrank-lever is slotted'at 60 and the stud-pin 61, adiustably secured in 63in the cam-plate 6i screwed to the well known actuator-bar 65 which extends longitudinally of the bed-plate in machines. of this type.

In the present instance means, preferably shear-cutters comprising movable and stationaryblades, are provided forsevering the stitching threads close to theneedle-hole at the under sideof the throateplate at the end of a stitchin'g'o-pe ration. Theinovable blade 66 is in the form of ,a lever looselyfulcrumedatone end'onthe stud-screw 67 and having adjacent'its opposite end a cutting edge 68which is adapted to cooperate with the complementary cutting edge 69 0f the ledger-blade 70 secured. in a recess in the under side of the throat-plate- 41 adjacent the needle hole 7-1 by a screw 72.. When the cutting blade is in advanced position the contacting faces. ofvthe ledger and cutting blades are yieldingly held in engagement by the arched spring-plate 73 which is seated over the rearward-extremity of the cutting blade 66. and held in position by thescrew 67. The spring-plate 73 isformed with a pair of bent lips Z4 which embrace opposite edges of the cutting blade and prevent relative turning movements between saidblade and spring plateabout the stud-screw67.

I To facilitate the entry of the cutting blade into the detained needle-loop, it is desirable to provide a certain amount ofclearance between the cutting blade and the throat-plate whenthe. former is inretracted position. To accomplish this result anelongated wedge-plate 755having one extremity tapered down toa thintedge 7 6is secured to the under surface of the throat-plate by a screw 77 and is, so positioned that as the cutting blade -is moved backfrom cutting position it will strike the inclined su1'face'78 of the wedge-plate 75, Figs. 5 and 6, and be forced away from the throat-plate a distance equal to the thickness of the wedgeplate75. I t

The cutting blade is actuated through a slidebar 79 havinga lost motionconnection with the actuator-bar 65. The slide-bar79 is fitted within the guide-way 80 formedin a guide-block 81 secured to the throat-plate.

by screws 82. One-extremity of the slidebar 79 carries a pin 83which is loosely fitted within the concentric apertures 84 and 85 formed, respectively, in the spring-plate T3 and the cuttingblade66-near thef'ulcram-screw 67'. A slight amount of play is provided between the opposite side-walls of the slide-bar 79 and guide-way "80, as

.shown in Fig.4, to permit limited sidewise movement of the bar 79 caused by the small movement of the pin 83 about the screw 67 as a center. The portion of the slide-bar 79 within the guide-block S1- is formed with a rectangular slot 86' within which projects an abutment S7 sustained by the threat-plate 41. Aexpansion spring 88 housed within the slot between the abutment 87' and the end wall 89 serves to yieldingly -return the cutting blade to initial position. The abutment-pin 90 sustained by the slide-bar 7 9 is adapted to-bestruck at a predetermined time by the tappet 91 secured by screw 92-to the lateral extension piece 93 which in turn is screwedto the actuator-bar 65; When thejparts are in initial position, Fig. 2, the tappet 91 is spaced from the abutment-pin 90 and for this reason the first stage of the longitudinal movement. of the actuator-bar does not transmit motion to the cutter-blade.

tremity, Fig. 2, carries a block 9 1 recessed at 95', to receive the lower extremity of the usual vibratory level-96 fulcruined at 97 to a bracket 98 sustained by the bed-plate and carrying at its upper extremity a pin 99 which fits into the cam-groove. 100 common to machines of this type. The, block 94; carries a stud-pin 101 which is embraced by the forked extremity of one arm of" a The actuator-bar 65 at'its left hand ex- During the operation of the machine, While, the pattern-cam 16 is impartlng lateral jogging movements to the work-holder to position the individual stitches of the cam-slot 100 acts upon the pin 99 to shift the lever. 96v and actuator-bar 65 to the left, Fig. 2, thus causing thefinger-4O to swing about its pivot and; advance the head 44 toward the needle-hole 71. As the shuttle seizes the'loop thrown out by the rising needle and is drawing out such loop, the head 44 is moved across the needle-path, thereby projecting the beak 45 between the shuttle-threadj t and the limb n of the nee-.

dle-loop. Atthe same time the loo-p-divid ing beak or point 46 is projected intothe needle-loop, as shown in Fig. 7.

By the time the needle reaches its highest positionthe shuttle has turned to cast-off position, Fig. 8, and the finger 40 continuing its advance reflects the shuttle-thread t, thereby pulling a given length from the bobbin 10, and holds the limb n of the needleloop in the throat 47 As the needle-loop is cast about the shuttle, the usual take-up 14 comes into action and draws up the limb .9 thus reducingthe size of the needle-loop, and tightening said loop about the head of the loop detaining finger 40. As the detaining finger 40 prevents the complete drawing up of the last needle-loop by the take up, the latter in completing its up-stroke will necessarily pull off an abnormal length of thread from the'supply. By virtue of the abnormal pull oif action of the takeup at this time enough slack thread is provided for the beginning of the next stitching operation and unthreadino of the needle by the take-up is avoided. After the take-up 14 has completed its up-stroke the parts are arranged as, shown in Fig. 9, wherein the bobbin-thread t and the limb n of the needle-loop are positioned inthe path of movement of the cutting blade 66. The

limb s of the needle-loop leads to the needleand is held above the path of movement of the cutting blade '66 by the surface 49. It is to be remembered that the cutting blade is at this time held away from the throatplate by the wedge-plate 7 5 and plenty of clearance is provided for the positioning of the limb 8 above the path of movement of the cutter-blade 66, by the raised surface 49 of the detaining finger 40. The thickened head 44 of the finger 40 thus serves to de tain and hold open the last loop of needlethread so that the advancing cutter-blade may enter the spread needle-loop and sever to impart the cutting impulse to the blade v66. At thistime the pin 61 is given a slight movement toward the actuator-bar 65 by the inclined extremity 63 of the cam-slot 63,

'(Figs. 9 and 12), and the bellcrank lever 56,

59 which carries thepin 61, is caused to move the detaining finger 40 toward the needle-hole a distance suflicient to compensate for the deflection of the limbn of the needle-loop and the bobbin-thread t'by the cutter blade as it crosses the needle-hole and carries the thread to the-ledger-blade, as

will be clear from' an inspection of F igs. 9

and 10.

. As the needledescends at the beginning of the next stitchingoperationthere is a suflicient length of thread projecting through the eye thereof to permit the formation of the first loop which is caught by the bobbin as shown in Fig. 11. At the same time an active portion of the cam-slot 100 serves to shift the actuator-bar 65 and impart a return movementto the detaining finger 40. As the V-shaped notch 48 is moved across the needle-path it. engages the needle-thread immediately after the free end thereof has been drawn down below the work'by the shuttle and carries it. backwardly across the active surface. 50 of the stationary nipper spring 51: against which it is held by the nipping surface 49 of the detaining finger; The thread is actually nipped just before the needle completesits first up-stroke. V

During the second reciprocation of the needle-bar the first needle-loop is cast about the bobbin and this loop catches the length of thread issuing'from the bobbin and draws it up to the work. Since this' length of bobbin-thread includes the amount pulled from the bobbin prior tov the preceding thread-cutting operation, it will be clear that therewill be a short end of bobbinthread projecting from the first-stitch. The beginning end of the needle-thread is held during the formationof the first two com Having thus set forththe invention, what I claim herein is r 1. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle-a bobbin'and a take-up, a

whereby said implement is caused to pull threadifrom the bobbin, and means for severing the needleand bobbin-threads;

2. In a sewing machine, in combination,

stitch-forming mechanism including a reciprocating needle a bobbin and a take-u'p, a

needleloop detaining implement, means whereby said implement is caused topull thread fromthe bobbin, means-for severing theneedleand bobbin-threads, and means whereby said implement is subsequently caused to nip the needle-thread. V a p 3. In alsewing machine, the combination withstitch-forming mechanism including a reciprocatingneedle a shuttle and a'take-up', of anlimplement adapted toenter and detain the last needle-loop acted upon by the takeup, said implement being movable across the path of the shuttle-threadand serving as a pull-off for the shuttle-thread, and means 7 for severing the needleand shuttle-threads.

4. In a sewing machine, in* combination, stitch-forming mechanism including a recip rocating-needle and a shuttle',a finger movable in a plane transversely of the needle, path to engage and pull off shuttle-thread and to enter andvdetain the last needlethread loop :cast about the shuttle, a threadcutter and means for moving the latter into operative engagement with the bobbinthread and one limb of the detained needle threadloopunm a '5. Insa sewing machine, in combination, a reciprocating needle and complemental looptaking means, a throat-plate, a finger movable inone direction to enter and detain the last needle-thread loop formed during the production of a'series of stitches, and a thread severing implement movable across the lead of that limb only of the detained needle-loop which leads to theIlast stitch,

said finger being movable in the reverse direction to nip'the needle-thread at the under side ofthe throat-plate at the beginning of the nextstitching operation.

6. In a sewing machine, in combination, stitch-forming mechanism including a reciprocatingtneedle and a bobbin, a work-plate having a needle-hole, a finger movable across theipath of the bobbin-thread to deflect the latter, said finger also serving to enter and detain the last needle-loop cast about the bobbin, and a thread severing implement mounted adjacent theneedle-hole and adapted to sever the bobbin-thread and that limb only of the detained needle-loop which leads to thelast stitch. I r

a 7. In a sewing machine, in combination,

stitch-forming mechanism including a rea ciprocating needle and complemental loop- 7 taking means, a throat-plate,-a thread -nip "ping surfacedisposed at the undersideaof V the throat-plate, a needle loopfdetainil'rlgimplement, a complementary th'read-nipe ping surface formed onsaid implement,

means for movingjsaid implement to a poa cutter moving automatically to sever the detained needle-loop, and means whereby said thread-nipping surfaces are caused to detain the end of the'needle-thread at the beginning of the next stitching operation.

v; 8, Inasewing machine, incombination, stitch-forming mechanism includinga re: ciprocating needle and a bobbin, thread severing means," cooperating thread ,nipping elements adapted to nip the free end ofthe needle-thread at the beginning of a stitching operation, and means for moving one 0t said elements sufliciently across the path of the bobbin-thread at the end of a stitching operation to pull off enough bobbin-thread to insure that the free end of the bobbinthread will be caught up at thelbeginning of the next stitching operation. I i a 9, In aisewing machine, in combination,

stitch-forming mechanism including a rec'iprocating needle} and a bobbin, thread severing means, coeperating thread-nipping elements-adapted to nip the free end of the needle-thread at the" beginning of stitchi ing operation, and means for moving one of said elements across the path of the bobbin-thread at the end of a stitching operation to pull ofi enough bobbin-thread to per mit the starting of a new stitchingoperation,-said last mentioned one ofsaid elements operating further to detain for the action ofthe thread-cutter the last needleloop cast about the bobbin.

ment movable across the path of the needle andlower-threads and having a firstprok jfection adapted to pass between the lowerthread and the last loop of needle-thread caught by the shuttle, and a second 'projec- 7 tion adapted to entertheneedle-thread loop.

v 11.1 In a sewing-machine, the combination with stitch-forming mechanism including a reciprocating needle and lowenthread looptaking-means, of a thread-severing implement, and a thread-engaging implement movable across the'path of the, needleand lower-threads, and having a first projection adapted vto pass between the lower-thread and the last loop of needle-thread caughtby the shuttle, and a second projection adapted to enter and position the needlethread loop for the;thread-severing operation,,said thread-engaging implement being further provided with a notch adapted to receive and deflect the loose end of the ing operation.

needle-thread at the beginning'of a stitch-..

12. In "a sewing machine, combination, stitch-forming mechanism lncludmg I a needle and complemental loop-taking means,-

a fixed'part having a thread-nipping surfa'ce, a needle-loop "detaining implement having a a complemental thread-nipping surface, a thread-severing knife mounted for movement relatively to said implement, and means for movingjsaid implement at the end of astitching operation to enter and detain the last loopof needle-threadfor the action of the thread-severing device and for subsequently moving said'implement' at the beginning of a new stitching. operation to nip the beginning end of the needle thread against said fixed part. I r

13. In a sewing machine, in combination, stitch-forming 'mechanism including a needle and shuttle, a thread-severing device, a part having a thread-nipping surface, a thread-positioning implement having a complemental thread -nipping surface, and means for moving said implement across thepath of the shuttle-thread at the end of a stitching operation to pull ofl'v shuttie-thread, and for subsequently 7 moving said implement at the'beginning ofa stitching operation to nip the beginning end of the needle-thread. 1

14:.=In a sewing machine, in combination, stitch forming mechanism including 1 :a

.needle and shuttle, a thread-severing device, a part having a thread-nipping sur-' face, a needle-loop detaining implement having a complemental threadmipping surface, and means for moving said implement across the path of the needle and shuttlethreads at theend of a stitching operation to pull of'f'the shuttle-thread and to detain V the last needle-thread loop for the action of a thread-severing device and Y for subsequently moving saidimplement at the beginning of a new stitchingoperation to nip the beginning end of the needle-thread. g 15. In a sewing machine, in combination,

a frame, stitch-forming mechanism includ-' mg a reciprocatmg needle and a take-up, a

stop-mechanism, a needle-loop detaining implement, a thread-severing implement, an actuator controlled by said stop-mechanism, said implements being carried by theframe independently of said actuatorand an operative connectionbetween said actuator and said implements whereby they are differentially actuated. r

16; In a sewing machine," in combination, stitch' forming mechanism including a reciprocating needle," an automatic stop mechanism, a thread-positioner", a thread-cutter, an actuator controlled by said stop mechanism, 'a connection between said actuator and said thread positioner, and a lost-motion connectionbetween said actuator andsaid threadcutter. r I r v c 17. In a sewing machine, 1n combination,

I'ofFthe needle-loop in the path of said movstitch-forming mechanism including a recip' rocating needle, a throat-plate carrying a ledger-blade at its under side, a cutter-blade mountedflfor movement in a plane parallel with said ledger-blade and also in a direction transverse to said plane, means for imparting cutting and return movements to rocating needle, a shuttle and a'take-up, of

an implement pivoted at "a fixed-point relatively to" said frame andr adapted' to'ent'er and detain the last needle-loop actedupon by the take-up, said implement being movable across the path of the shuttle-thread" and serving as a pull-off for the shuttle-thread, and means for severing the needleand shuttle-threads. l r

19. In a sewing machine, the combination with a frame including a throat-plate, a thread-nipping surface, sustained at the under side of the throat-plate, and stitchforming mechanism incorporated in said frame and including a reciprocating needle, a shuttle and atake-up, of an implement pivoted to said throat plate at a'fiXed point and adapted to move in one direction to enter and detain the last needle-loop ofa series for the action of the thread-cutter and to pull off shuttle thread, said implement being movable in therever'se directionat the beginningof a stitching operation to nip-the needle-thread against said thread-nipping surface. I .'Z

QOQThreadcutting and nipping mechanism for sewing machines compris'ing. a thread-cutter and means including a single movable thread-engaging implement operating to. pull off bobbin-thread, to detain and spread the last needle-loop. of a series for the action of" the thread-cutter and to nip the beginning end of the needle-thread at the start of a new stitching operation. 7

' 21; In a. sewing machine, the combination with a frame including a throat plate having a needle-aperture,and stitch-forming mechanism incorporated in saidframe and including a reciprocating needle, a shuttle and a take-up, of a thread-cutter including a movable blade' anda fixed blade, the latter being carried by the throat-plate adjacent the needle-aperture, and a "needle-loop detainer andspreader about which the needle thr'ead i. needle-loop detainer'and spreader being movablezacross the lead of thebobbin-thread'and operatmg to pull off bobbin-threadandposi tion said bobbin-thread and one'limb only able jbladel 22. In a sewing machine, the combination with a frame including a throat-plate and stitch-forming mechanism incorporated in said frame and including a reciprocating needle,'a shuttle, and a take-up, of a threadcutter including a movableblade sustained beneath the throat-plate, and a needle-loop detaining and spreading finger moving in a plane substantially parallel to the throatplate and having a thickened extremity adapted to position the two limbs of the last needle-loop mainly at opposite sides of the plane of movement of the cutter.

23. In a sewing machine, the combination with a frame including a throat-plate and stitch-forming mechanism incorporated in said frame and including a reciprocating needle, a shuttle, and a take-up, of a threadcutter including a' movable blade sustained beneath the throat-plate, and a needle-loop detaining and spreading finger moving in a plane substantially parallel to the throatplate and having a thickened extremity adapted to position the two limbs of the last needle-lo0p mainly at'opposite sides of the plane of movement of the cutter, said finger being further formedwith a reduced shank- ,up, a needle-loop detainer and spreader having a loop-dividing point, automatic means for movingsaid point into the last needleof said loop by said loop-takeiyand means for severing the detained needle-loop.

In testimony whereof, I have signed m name to this specification.

ALBERT F. FIFIELD.

loop during the .earlypart of the distension

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