US2298246A - Machine for attaching articles - Google Patents

Description

Oct. 6, 1942.. M. MOCANN MACHINE FOR ATTACHING AfiTIcLns Filed May 25, 1940 4- Sheets-Sheet 1 GUM/MAM Oc t. 6, 1942. M. McCANN 2,298,246 1 MACHINE FOR ATTACHING ARTICLES File d May 25, 1940 4 Sheets-Sheet 2 Oct. 6, 1942. M. Mcc N I 2,298,246

MACHINE FOR ATTACHING ARTICLES Filed may 25; 1940 4 Shets-Sheet s Oct. 6,1942. M. MC NN 2,298,246

MACHINE FOR nmcame ARTICLES Filed May 25, 1940 4 Sheets-Sheet 4 E E g 2 E E F E '5 6 5g D g 5 2 Q2 1.1.! g Egg 5+ E START 1 4 g c E5 I INIP$+CUT5 z. THD. END u 0 L I 0 5k 2 c E 6 m 2' 4 9 RELEASES F Y Z NIPPEDEND h CLO5ED 3 g I0 I 56' OPEN g g5 curs THD. L k 1 N|P5+CUT5 55 fi.- THD.END 93 7 LL M m 8 :5 95 12 96' I3 1' i l4 g 15 v k E x 44 z w 2% w L 44; m 1

O 5 START r fi g K l \n I? -"T' 1 T8 a 80 1 Q l J I9 RELEASES, l .g 4 NIPPEDEND I/ I Q a 20 I? curs THD. START ['Iichael mean Wfne$$ Patented. Oct. 6, 1942 UNITED STATES PATENT OFFICE V V mcnnmron i'iffo nmc an'rrcms Michael McCann. Ozone Park, N. Y., asaignor to The Singer Manufacturing Company, Elizabeth, N. 1., a corporation New Jersey Application ma 25,

thread-end appearing on the under side of the g 13 Claims. This invention relates to a machine for attaching articles to work'and more particularly to a machine for attaching articles to work by a plurality of disconnected groups of stitches. A fourhole flat button is a good example of an article in which this form of attachment is desirable and therefore, for convenience, this invention will be shown and described as embodied in a flat-button sewing machine, but it is to be understood that the invention is not limited 'to'button-sewing machines and that other embodiments and uses are contemplated.

- A primary object of this invention is to provide an improved article-attaching machine adapted, in a single continuous operation, to attach articles to work by two parallel groups of stitches,

without any connecting or cross-over stitch be-- tween the'groups. Another, object of the invention is to provide, in an article-attaching machine as above described, an improved automatically actuated thread-clamping and -cutting mechanism which will nip the thread at the beginning of each group of stitches'to facilitate the forming of stitches; which will trim oi! the beginning end of the thread beneath and'close to the work; and which will sever the thread at the completion of each group of stitches. V

A further object of the invention is to provide, in combination with a thread-cutter and -clamp,

. as above described, thread-controlling means, in

addition to the usual thread take-up adapted to pullback on the thread at the beginning of each I group of stitches so that the length of thread-end required to be trimmed off will be reduced to a thereby preventing thread wastage, and which also wiil'glve up thread to the stitchforming elements as maybe required for the proper formation of stitches.

a still further object is to provide threadclampingand thread-tensioning means actuated in timed relation with the thread-cutter, threadnipper and thread-controller so that at certain times during the cycle of operation thread may be drawn freely vfrom the supply while at other times the thread is clamped and drawing of thread from the supply is precluded, all as is required for the proper functioning of the stitchforming and thread-cutting mechanisms. Still another object of the invention is to provide an improved method of attaching. articles to work which will eliminate the usual cross-over stitch on the face of the article; which will securely anchorthe beginning end 'of the thread; and

which will reduce, to a minimum, the length of 1940, Serial No. 337,16l

work.

With the above and .other objects in view, as

will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the'invention and. the advantages'attained thereby will be readily understood by those skilled in the art.

In the drawings, Fig. 1 is a side elevation, partly insection and with a side cover-plate thereof described and showing alsoa portion of the needie-bar vibrating mechanism.

Fig. 4' is a detail plan view of the actuating means for the thread-cutting and -nipping mechanism,

Fig. 5 is an enlarged vertical sectional view substantially along the line 5-5 of Fig. 4 showing more particularly the thread-cutting and -nlppi ng mechanism and a portion of the stitchforming mechanism.

Fig. 6 is a disassembled perspective view of the machine throat-plate and elements of the threadcutting and -nipping mechanism which cooperate therewith. I 40 Figs. 7, 8, 9,10 and ll'arelongitudlnal vertical sections takensubstantially on the line 5-5 of Fig. 4 illustrating the action ofthe thread-cutter and -nipper in conjunction with the stitch-forming mechanism.

Fig. 12 is a transverse vertical section substantially on the line I2I2 of Fig. 4 showing the coaction oi the thread-cutter'and the looper in the severing of the needle-thread.

Figs. 13, 14 and 15 are enlarged vertical sectional views through a work-piece and a button,

illustrating the manner in which the nipped beginning end of the thread is drawn up and covered by the button-attaching stitches.

Fig. 16 is a diagrammatic veiw illustrating the action oi the thread-tension, thread-clamp.

removed, of a button-sewing machine embodying thread-controller and thread-cutter and -nipper in conjunction with the reciprocations of the needle.

Fig. 17 is a plan view of one product of the.

machine shown in Fig. l, to wit: a four-hole button attached to a work-piece by two disconnectd groups of stitches.

Referring more specifically to the drawings the invention is illustrated as embodied in a sewing machine comprising a base I, standard 2, overhanging arm 3 and a head 4 which carries a removable face-plate 4. Joumaled within the base I is a main shaft carrying loose and fast pulleys 6 and I, respectively, adapted to be driven by a power belt 8. A combined stop-motion mechanism and belt-shifter, designated generally as 9, is actuated by a conventional treadle mechanism, not shown, and is adapted to shift the belt from the loose pulley 6 to the fast pulley 1 to start the operation of the machine. At the end of the operation the stop-motion is tripped automatically whereupon it shifts the belt to the loose pulley and brings the machine to rest with the parts in a predetermined position. Inasmuch as the stop-motion mechanism of this machine forms no part of the present invention, detailed illustration and description thereof is deemed unnecessary.

Rotatably journaled in bearings provided by the base I, and driven from the main shaft 5 by conventional mechanism common to the Singer Class 1'75" button-sewing machines, is a looptaker-shaft I0, which carries, at its forward end,

a loop-taker, s'hown specifically as a rotary chainstitch looper II. Cooperating with the looper in the formation of stitches is an eye-pointed needle I2 secured in the lower end of a needle-bar I3 mounted, for endwise reciprocation andv lateral vibration, in the head 4, Adjacent its upper end.

the needle-bar is reciprocally mounted in a pivotblock I4 carried by a stud I5 journaled in the machin head. The lower portion of the needlebar is reciprocally mounted in a block l6 carried by the forward end of a vibratory lever I'I, fulcrumed on a stud I8 and carrying at its rearward end a roller or stud I9 which tracks a needlebar vibrating cam-groove 20 formed in the upper face of a rotary cam-disk 2I. The disk 2| is secured upon the upper end of a vertically disposed shaft 22 journaled in the standard 2 and rotated from the main shaft 5 by a worm and wormwheel speed-reduction gearing, designated generally as 23, having a ratio of 20 to 1. Thus twenty rotations of the main shaft will produce one complete rotation of the cam-disk 2| and consequently one complete cycle of operation of the machine.

The needle-bar is reciprocated from a rockshaft 24 journaled in bearings formed in bearingbrackets 25 and 2B provided'by the arm 3. At its forward end the rock-shaft 24 carries an arm 21 which is connected by a link 28 to a collar 29 secured upon the needle-bar. Oscillatory motions are given to the shaft 24 by an eccentric-30 secured upon the main-shaft 5 and connected by a pitman 3| with a rock-arm 32 secured upon the rearward end of the shaft 24. By reason of this construction the needle-bar is given one reciprocation for each rotation of the main-shaft I and consequently twenty reciprocations in one complete cycle of operation. For a more complete understanding of the needle-bar reciprocating and vibrating mechanism, reference may be had to United States. patent to R. L. Plumley No. 1,671,124, May 29, 1928.

groove 0' which actuates an arm 0 secured upon the lower end of an upright shaft 0 journaled in the machine base and connected at its upper end to the clamp and work-plate. From the foregoing it will be understood that the needle is adapted to be reciprocated in two vertical paths corresponding to the holes a and b of the button B in Fig. 17, and that in each reciprocation the needle-thread loop is seized by the looper II in the formation of chain-stitches. After the needle has been reciprocated a suillcient number of times to produce the group of stitches designated as d in Fig. 17, the work-plate P and buttonclamp, together with the work W and button B held thereby, are 'shifted endwise toward the free end of the base I thereby causing'the reciprocatory and vibratory needle to enter the holes a and b in the buttom and together with the looper to form a group of stitches e'. It will be noted that there is no connecting stitch between the groups of stitches d and e. The means for severing the needle-thread after the formation of the group d, so that no connecting stitch is formed, will hereinafter be described.

As shown in Figs. 1, 2 and 3, the needlethread T passes from the supply through threadguides 33 and 34, between thread- tensions 35 and 36, thence through thread-eye 31, thread-clamp 38, thread-eyes 38' and 39, thence downwardly and around a roller 40 forming a part of a thread-controller K. From the roller 40 the thread extends upwardly and around a take-up roller 4I carried by the collar 28 secured to the needle-bar. Next the thread extends downwardly and through a light-tension thread-guide 4| to a guide 42 secured upon the lower end of the needle-bar and thence through the eye I2 of the needle I2. It will readily be understood that as the needle-bar I3 and the roller 4I carried thereby descend, the length of the bight of thread extending from the roller 40 over the roller M and to the needle eye is shortened and thus thread is given up to the looper. Conversely when the needle-bar rises the bight of thread is lengthened and the thread is pulled back through the eye of the needle thereby setting the stitch.

The support for the thread-controller K, including the thread-guiding roller 40, comprises a lever 43 fulcrumed on a screw 44 threaded into the arm of the machine. The rearward end of the lever 43 (see Fig. 1) carries a roller 45 later to be referred to. A coil-spring 46, having its upper end connected to a pin 41 secured in the machine head 4' and its lower end connected to a similar pin 48 carried by the forward end of the lever 43, normally holds the forward end of the lever elevated and in contact with the lower end of an adjustable stop 49 carried by the faceplate 4 When the forward end of the lever 43 is in contact with the stop 43, the roller 45, carried by the rear end thereof, is maintained slightly above the upper flat face of the camdisk 2|.

Secured upon the upper face of the disk 2I This clamp and plate in position to travel beneath the roller is are two cam-blocks (Fig.3), each having a first camsurface 5| (Fig. 1*) adapted to ride beneath andlift the roller 45, thereby-to give the thread-' controller K a first downward movement, in opposition to the spring 48, to draw thread back through the needle, and a second cam-surface 52 adapted to further lift the roller 45, thereby to cause the thread-controller to be given a further thread pull-back action. As the rear end The plunger 55 is normally maintained depressed by a coil-spring 51 surrounding the plunger and interposed between the upperwall of the arm 3 .and a collar 58 secured on the plunger. The lower end of the plunger 55 passes loosely through the bifurcated end of a lever 59 fulcrumed, at one (end, on a shoulder-screw 50 threaded into the bearing-bracket 25. A washer 6| surrounds the plunger 55 and rests upon the upper face of the lever 59. Interposed, between the washer BI and a collar 52 fixed upon the plunger is a coil-spring 83 which constitutes a yielding connection between the lever 59 and plunger 55. A bolt 54 having a rounded head. 65 is adjustably carried by the lever 59 intermediate its ends and is held in adjusted position- .plete formation of the first. stitch the thread tension 35 is maintained open and the tension 38 is temporarily opened sothat they do not impose any drag on the thread- The auxiliary means for temporarily releasing the tensions comprises -a rockshaft l8 joumalled vertically in bearings H and 12 provided by the machine standard. At

'its lower end the shaft-ll carries an arm 13 provided at its free end with a roller 14 which tracks a cam-groove 15 formed in a cram-disk 16 secured upon the shaft "beneath the camdisk'2l. Fixed upon the upper end of the shaft 18 (see Fig. 3) is a two-armed lever II, the free ends of the arms 18 and 19 of which are beveled and are adapted to enter between-the thread.- engaging disks of the thread-tensions and 35, respectively, thereby to spread the disks apart and relieve the tension on the thread passing therethrough.

As hereinbefore stated the present machine is adapted to attach articles to work by two dis- 1 connected groups-of stitches made during a single continuous two-stage operation of the machine.

To accomplish this result; one group of stitches is madeand, while the machine continues to run, the thread is cut, the second group is made and the thread is again out.

The thread-cutter comprises a combined thread-cutting and -nipping blade 80 located by a clamp-nut 65. The head is adapted, at

predetermined times, to be engaged and lifted by the upper rounded heads of two studs 61 carried 'by the cam-disk 2i and spaced apart 180 degrees. When either of the studs 61 passes beneath'the head 65' the lever 59 is lifted and the thread T is clamped between the plunger head 55 and the overlying plate 54. As the studs pass from beneath the bolt head the plunger is again depressed by the spring '51 and the thread is released.

The thread-tension 35 hereinbefore referred to is of the intermittent type and normally is adapted to apply a tension to the thread during each up-stroke of the needle-bar and take-up 4| carried thereby, to set the stitch and to release the thread during the down-stroke of the needle when it is pulling thread from the supply. The tension 35 is released periodically by a cam 68 secured upon the main-shaft 5.through the medium of a spring-depressed push-rod 59, as shown more fully in my prior United States Patent No. 1,983,555, Dec.;1-1, 1934. The threadtension 36 is of the constant type and applies a tension to the thread at all times except as hereinafter described.

During the formationof the first stitch of each beneath the throat-plate X and secured upon the-forward end of a cutter-actuating bar 8| mounted for endwise sliding movement in the bed I. The rearward end ofthe bar 8! is pivotally connected, at 82, to one end of an extensible link 83, the other end of which is pivotally attached to one end of a lever 84 fulcrumed at 85 on a plate 88 secured to the machine base. 'Intermediate its ends the lever 84 carries a roller 81 which tracks a cam-groove 88 formed inthe upper face of a cam-disk 89 securedupon the shaft 22 above the cam-disk c. The cam-groove 88 is formed so as to give the bar 8!, and blade 88 carried thereby, backward and forward movements, as are required to give the thread-cutter and -nipper their proper actions, as later will be arranged between the under side of the throatto be referred to. After the first stitch has been made and the thread has been anchored in. the

. work the tensions '35 and 36 may operate in 7 plate X and the upper face of a complemental thread-cutting blade90 provided with amaperture 90. The blade 90 is secured to the throat.- plate byscrews 9fand is adapted to be placed under tension, so as to exert an upward pressure on the blade 88, by a screw 92 passed loosely through the blade and thmaded into the throatplate.

The thread-cutting and -nipping blade 88 is formed with a notch 93, the transverse wall 94 of which is beveled so as to constituteja cutting edge 94 and an aperture 95 having a short longitudinal wall 95 inclined downwardly and termina-ting at its lower end in a cutting edge 96 The cutting edge 94 is adapted to cooperate with a complemental cutting edge 90 provided by the blade 98 to shear off the beginning end of the thread, as hereinafter will be described.

The cutting edge 96 of the blade 80 is adapted,

'at predetermined times, i. e., at the completion 'of of needle-thread against the cutting edge 98 and in Fig. 12.

The cutting and nipping blade 80 underlies throat-plate.

severs the thread, as indicated in dotted lines the throat-plate X adjacent the needle-hole :1: therein, and, at predetermined times during the sewing cycle, nips the end of the thread between the upper surface of. the blade 80 and the lower surface of the throat-plate, as shown in Figs, 8, 9, 13 and 14, to facilitate theformation 01 stitches.

Operation The two-stage cycle of operation of the machine, when sewing a four-hole button by two of button-sewing machine. To simplify the drawings, the work-clamp and work-supporting plate have been omitted from Figs. '7 to 15 and the work-piece is shown as resting directly on the Next the operator trips the stopmotion to start the machine. During the first down-stroke of the needle, the cam 88 shifts the thread-cuttting and -nipping plate 80 to the left from the position indicated in dotted lines and marked Start, in Fig. 16, to the position designated as e, so that the needle descends in the notch 93 to the right of the cutting edge 94 As the needle starts its first up-stroke,.the looper'engages the thread-loop and pulls the thread downwardly, as indicated in Fig. 7. At the end of the first up-stroke of the needle, the thread-cutting and -nipping blade 80 is moved to the right to the position designated as j, thereby cutting off the beginning end t of the thread and nipping the thread between the blade 80 and the throatplate, as indicated in Fig. 8. As shown by Fig. 16;

during the first complete reciprocationof the needle, the tensions 36 and 36 are closed, as indicated by the word "On; the thread-clamp '38 is closed to prevent drawing of thread from the supply; and the thread-controller K is moved downwardly, from the Start position to the position designated as 1 in Fig. 16, thereby drawing back on the needle-thread and reducing the length of the free 'end of the thread below the throat-plate. With the blade 80 in the position indicated by j, the needle is aligned with the aperture 95 and the next eight reciprocations are made, respectively, in the positions indicated by the numbers 24-4-5-5-1-8-9; the needle being vibrated laterally between successive stitches and forming the group of stitches designated as d in Fig. 17.

During the second reciprocation of the needle, the tensions 35 and 36 are open, as indicated by the word Off, in Fig. 16, and the thread-clamp 38 is open, so that thread readily may be pulled from the supply, the thread-controller K is moved upwardly to the position designated as 2 thereby to give up thread to the stitch-forming mechanism, and the blade 80 remains stationary and continues to hold the beginning end of the thread nipped against the under side of the throatplate.

During the third reciprocation of the needle, the thread-tensions are closed and remain closed controller remains stationary. The thread-cutting and -nipping blade remains stationary through the second to ninth reciprocations of the.

the position shown in Fig. 9 to the position shown in Fig. 10, likewise from the position I, in Fig.

16, to the position a to release the nipped end of the thread. During the tenth reciprocation of the needle,, the cutting and nipping blade is moved tothe left from the position a (Fig. 16) to the position It. During this movement the cutting edge 96 of the blade III-is brought into the path of movement of one limb oi the threadloop which is forced thereagainst by the wing of the looper, and severed as hereinbefore described. During the tenth reciprocation of the needle, the thread clamp is closed and the thread-controller K draws thread back from the needle to tighten the thread and assist in the thread-cutting operation.

The above described partial operation of the machine completes the formation of the group of stitches d, shown in Fig. 17, and thereafter severs the needle-thread thus completing the first stage of the operation. The machine continues to operate and during the eleventh down-stroke of the needle the button-clamp C and work-plate P are moved .endwise to the left thereby positioning the holes a and b of the button B in alignment with the needle. Continued operation of the machine repeats the partial operation, hereinbefore 'described, thereby similarly producing the group of stitches e and severing the thread at the end of the stitching cycle, whereupon the stop-motion brings the machine to rest, at the completion of the second stage of operation, with the needle elevated, and the threadcutting and -nipping blade in the position indicated by i, in Fig. 16. 4

In making the group of stitches d, the needle makes its ninth and tenth reciprocation in the same .hole in the button thereby producing a knotting or tying stitch. Likewise the group of stitches e is concluded by a knotting or tying stitch, the needle, for this purpose, making its nineteenth and twentieth reciprocations in the same hole.

In the above description of the operation of the machine, the normal and constant take-up action of the take-up 4| and the normal intermittent action of the tension 35 have been disregarded inasmuch as those actions are conventional and have no special significance with the present invention.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine having a frame including a work-support and an overhanging head, an endwise reciprocatory thread-carrying needle mounted in said head, and a rotary loop-taker located beneath said work-support and cooperating with said needle in the formation of stitches; the improvement which consists in the provision of a thread-cutter comprising a shiftable cutter-blade having a thread-cutting edge arranged substantially parallel to the axis of rotation of said loop-taker, and means for periodically shifting said cutter-blade to position said thread-cutting edge in the path of movement of throughout the succeeding reciprocations includ- I one limb of the thread carried by the loop-taker whereupon further rotation of the loop-taker,

carries the thi'ead into contact with said threadcutting edgeand severs the thread.

aaoaa-ie thread-clamp and the stitch-forming mechanism; means for operating the machine through 2. In a sewing machine having an endwise reciprocatory thread-carrying needle and a rotary chain-stitch looper cooperating with said needle in the formation 01 stitches; the improvement which consists in the provision of a thread-cutter comprising a shiftable cutter-blade having a thread-cutting edge arranged transverse to the path of rotation of said looper, said blade having an operative position with its cutting edge within the path of movement of one limb of the thread-loop carried by said looper and an inoperative position with said cutting edge remote from said path, and means operative at a predetermined point in the cycle of operation of the machine for shifting said cutter-blade from its inoperative position into its operative position so that the looper will carry one limb of the needle thread loop into contact with said cutting-edge to sever the thread.

3. In a sewing machine having an endwise reciprocacy thread-carrying ,needle and a looptaker cooperating with said needle in the formation of stitches; the improvement which consists a predetermined article attaching cycle, means for nipping the sewing thread, ineans for severing the sewing thread, and means for actuating 7 each of said tension-releasing means, thread.-

7. In a sewing machine having stitch-iorming mechanism, a thread-tension, means for releasing said tension, a thread-clamp located intermediate the thread-tension and the stitchin the provision of a thread-cutter comprising a shiftable cutter-blade having a thread-cutting edge arranged transverse to the path of movement of said loop-taker, said blade having an operative position withits cutting edge within the path of movement of one limb of the threadloop carried by said loop-taker and an inoperative position with said cutting edge remote from said path, and means rendered effective at the end of the stitch forming cycle of the machine -for shifting said cutter-blade from its inoperative position into its operative position 'so that the loop-taker will carry one limb of the needle-- thread 100p into contact with said cutting-edge 'forming mechanism, means for operating the 7 machine through a predetermined two-stage sewing cycle, a combined thread-nipping and -severing blade for nipping the thread at the beginning of each stage and for severing the sewing thread at the end of each stage, and means for actuating each of saidtension-releasing means, thread-clamp, and thread-nipping and -severing blade a plurality of 7 times during said sewing cycle.

8. In a sewing machine having stitch-forming mechanism, a thread-tension, means for releasing said tension, a thread-clamp located intermediate the thread-tension and the stitchforming mechanism, a thread-controller located intermediate the thread-clamp and the stitchforming mechanism; means for operating the machine through a predetermined sewing cycle,

adapted to cooperate with the cutting edge of said stationary blade, and means for periodically shifting said shiitable blade to cause said cooperating edges to trim'ofi the beginning end of the thread and thereafter to align the other cutting edge of said shiftable blade with one limb of a thread-loop carried by said loop-taker whereupon said loop-taker carries said threadlimb into contact withsaid other cutting edge cle holding means, stitch-forming mechanism, a thread-tension, means for releasing said tension,

a thread-clamp-located intermediate the threadthread-clamp, thread-controller andv means for nipping the sewing thread, means for trimming oi the free end of the nipped thread, means for severing the sewing thread after the completion of a group of stitches, and means for actuating eachof said tension-releasing means, thread-clamp, thread-controller, thread-nipper, thread-trimmer and thread-severing means a plurality of times during a complete sewing cycle.

9, Athread-cuttihg mechanism for sewing machines having a rotary looper and a complemental'needle carrying a sewing thread, comprising a movable thread-cutting blade having a pluralityof thread-cutting'edges, a stationary cutting blade adapted to cooperate with one of said cutting edges, means to shift said movable blade to cause said cooperating edges to cut off the beginning end of said sewing thread, and means operative after a predetermined number of stitches have been made to give to said movable blade another movement to cause the other cutting edge thereof to be broughtinto the path of movement of a limb of .a thread-loop carried by said looper whereby the looper carries said limb against said other cutting edge to sever said thread.

10. A thread-cutting mechanism for sewing stationary cutting blade adapted to cooperate with one of said cutting edges, means to shift said movable blade to cause said cooperating edges to cut oil the beginning end of said sewing tension and the stitch-forming mechanism, a

thread-controller located intermediate the threadjand means operative after a predetermined number of stitches have been made to give to said movable blade another movement to cause the other cutting edge thereof to be brought into the path of movement of a limb ofa threadloop carried by the wing of said looper whereby the looper wing carries said limbagainst said other cutting edge to sever the thread.

machines having a. loop-taker and a complemental needle carrying a sewing thread, com-'- with one of said cutting edges, means to shift,

said movable blade in one direction to cause said cooperating edges to sever said sewing thread, and means to move said blade in the opposite direction to cause the other cutting edge thereof to be broughtinto the path of movement of a limb of a thread-loop carried by said loop-taker whereby the loop-taker carries said limb against said other cutting edge and severs the thread.

12. A thread-cutting and -nipping mechanism for sewing machines having a throat-plate, a rotary looper and a complemental needle carrying a sewing thread, comprising a movable thread-cutting and -nipping-blade located beneath the throat-plate and having a thread-nipping portion cooperating with the underside of the throat-plate and a plurality of thread-cutting edges, a stationary cutting blade adapted to cooperate with one of said cutting edges, means to shift said movable blade to cause the thread to be nipped between the blade and the throatplate and to cause said cooperating edges to'trim oil the free end of the nipped thread, and means operable after a predetermined number of 11. A thread-cutting mechanism for sewing blade another movement to cause the other cutting edge thereof to be brought-into the path of movement of a limb of a thread-loop carried by said looper whereby the'looper carries said limb against said other cutting edge to sever the thread.

13. A thread-cutting mechanism .ior sewing machines having a throat-plate, a loop-taker and a complemental needle carrying a sewing thread, comprising a stationary cuttersblade adjacentto but spaced from said throat-plate, a movable I thread-cutting and -nipping blade located between said stationary blade and said throat-.

mined number of stitches have been made to give 0 to said movable blade another movement to cause the other cutting edge thereof to be brought into the path of-movement of a limb of a thread-' loop carried by said loop-taker whereby the looptaker carries said limb against said other outstitches have been made to give to said movable ting edge to sever the thread.

MICHAEL McCANN.

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