US1877159A - Thread trimmer for sewing machines - Google Patents

Description

Sept. 13, 1932. A. F. CARLSON THREAD TRIMMER FOR SEWING MACHINES Filed Jan. 22, 1927 5 Sheets-Sheet l W AT Tys.

Inventor. Axel F. Carlson byiausiwlzflx Sept. 13, 1932. A. F. cARLsoN 1,877,159

THREAD TRIMMER FOR SEWING MACHINES Filed Jan. 22, 1927 5 Sheets-Sheet 2 Inventor. Axe! F. Caflson Sept. 13, 1932. A. F. cARLsoN 1,877,159

THREAD TRIMMER FOR SEWING MACHINES Fi-led Jan. 22. 1927 5 SheetsSheet 5 Invenror.

Axel F. Carlson I Aflys.

Sept. 13, 1932. A. -F. CARLSON 1,877,159

' THREAD TRIMMER FOR SEWING MACHINES Filed Jan. 22, '1927 5 Sheets-Sheet 4 t Fig. 5.

ssf 35 l| jwgiw I 5. 1 5 J I 66 E y as JP; s7 a 95' H4 Ha lnveni'or I Axel F. Carlson b MMzzW Arrys.

p 9 A. F. CARLSON 7 59 THREAD TRIMMER FOR SEWING MACHINES Filed Jan. 22 1927 5 Sheets-Sheet 5 Fig 6.

Kil Iii N r ,I/I/I/I/l/l/Il, 7/1"!"|llllIIIIllllhllIIllllIlllllllllllllllfi/I/I/II/ I n venTor. Axel F Carlson Patented Sept. 13, I932 hairs STATES Q PATENT oFFic M axnn r. CARLSON, F CAMBRIDGE, ass'ncnnsnrrs, ASSIGNQR T0 TIE-IE assessor- TON HOLE amour-an COMPANY, on season, MASSACHUSETTS, A CORPORATION OF MAINE ITHREADTRIMMER ron snwine MACHINES Application filed January 22, 1927. serial No, 162,890.

This invention relates to sewing machines of that class which are constructed to per form a predetermined sewing operation and then automatically come to rest, (a buttonigi'hole sewing machine being an exemplification of a sewingmachine of this type), and particularly to means for trimming the thread atthe end of the sewing operation.

In sewing machines of the type above reij ferred to the stitch-forming mechanism and work-holding means have a relative feeding movement during the sewing operationand in some sewing machines of this type the stitch-forming mechanism and the work- 'l t holding means have a further relative movement after the sewing operation is completed during which further relative movement a length of thread is drawn through the throat 7 plate. In a buttonhole sewing machine this zt'k-further or additional relative movement between the stitch-forming. mechanism and work-holding means which occurs after the stitching is completed is usually for the pur pose of carrying the parts from stitching poss sition to buttonhole cutting position. As stated above during this relative movement by which the parts are brought relatively into buttonhole cutting position a length of thread will be drawn out through the throat S oplate and the present invention has for its object to provide novel means for cuttingthis thread close to the work. i

The stitch-forming mechanism is brought.

to rest at the end of the stitching operation "with the needle raised and frequently at this time a loop of needle thread is retained by.

' and accurately I have provided herein a pulldown device which is actuated to engage the thread or threads beneath the'workand pull them down away from or separate them from.

the work and I have provided a cutter opverating in a plane parallel to the plane of the work which is adapted to cut thethrea d between the pull-down and the work. The

operation of the pull-down separates the thread from the work and places it in position to be acted on by the cutter.

In some sewing machines of this type the under-thread-manipulating mechanism is mounted on a turret which is turned at each In the present invention the thread cutter is actuated subsequent to the releasing of the work clamps so that when the thread is cut the work is unclamped. In accordance with V this feature of the invention the thread cutter is actuated in conjunction with the means for releasing the work clamps, the two devices being so timed that the work clamps are released first and then the thread is cut.

The device herein shown is further provided with means for so manipulating the under thread that a proper length will be left after the cutting operation to start the stitching on the next seam.

In order to give an understanding of the invention I have illustrated in the drawings a selectedembodiment thereof which will now be described after which the novel features will'be pointed out in the appended claims.

Fig. l is a side view of a buttonliole sewing machine having my improvements applied thereto Fig. 2 is a plan-view illustrating the pulldown and the thread cutters, these parts being in theirinoperative position;

Fig. 3 is a similar View. showing the pull-. down inits operative position and illustrating the cuttersin their inoperative position;

Fig. dis a fragmentary view showing the cutters and the means for operating them;

Fig. 5 is a fragmentary sectional view illustrating the under-thread-handling mechanism;

Fig. 6 is a fragmentary side view illustrating the operation of the cutter-actuating mechanism;

Fig. 7 is a perspective view showing the pull-down;

Fig. 8 is a fragmentary view showing the position of the work at the end of the stitching operation;

Fig. 9 is a view showing the position of the work after it has been moved relatively into buttonhole cutting position, said Figure also showing the operation of the pull-down and thread cutter;

Fig. 10 is a fragmentary view of the turret showing a slightly different embodiment of the invention; I

Fig. 11 is a sectional view taken at right angles to Fig. 10, and showing the pull-off device illustrated in said Fig. 10.

Before proceeding to describe the features included in the present invention 1 will refer briefly to the sewing machine as a whole and to the parts which are of known construction and are common to other sewing machines of this type.

The work 1 on which the stitching is to be performed is clamped to the bed 8 by means of work clamps 4 which clamp the work against clamp plates removably carried by the bed and situated directly beneath the work clamps 4. These work clamps 4 are carried on pivoted arms 5 as usual.

The stitch-forming mechanism comprises the usual needle 6 which operates from above the work and a thread-manipulating mech' nism 99 located below the work and which I will hereinafter refer to as the underthread manipulating mechanism because it is situated beneath the work.

The needle 6 and the under-threadmanipulating mechanism 99 co-operate to concatenate thefstitches in usual manner.

The stitch-forming mechanism is carried by a suitable frame 7 which is inounted on the bed 3. I Said stitch-forming mechanism and work-holding means have a relative movement as usual in sewing machines of this type and while this relative movementmay be secured either by moving the work-holding means or by moving the stitch-forming mechanism yet in the particular embodiment of the invention herein shown it is secured by movement ofthe stitch-forming mechanism, the frame 7 being slidably mounted on the bed 3 and means being provided for giving the frame 7 a movement both during and after the stitching operation.

In this device, therefore, the work is clamped on the stationary bed and the feeding of the work relative to the stitch-forming mechanism is performed by the back and forth movement of the frame 7.

The operation of the machine is controlled through the usual main cam 8 which is carriedby the frame 7.

In sewing machines of this type it is a common practice to mount the under-thread-manipulating mechanism on a turret 29 which is rotatably mountd in bearings in the depend ing portion 30 of the frame, said turret carrying the usual throat plate 31 that is situated directly beneath the needle 6 and is provided with the usual opening through which the needle operates and through which the thread is led to the work 1. This turret is rotated at the ends of the buttonhole to carry the stitching around the buttonhole ends in usual manner.

The opening and closing of the clamps 4 is controlled by a toggle lever device of known construction and it comprises two toggle members 9 and 10 pivoted together at 11, the toggle member 10 being pivoted to the bed 3 at 12, and the toggle member 9 being pivoted to a bracketarm 13 depending from a swing ing frame 14 which is pivoted to the bed at 15. This frame has at its rear end a lip 16 which engages another lip 17 formed on an arm 18 that is rigid with the clamp arms 5, these clamp arms being pivoted at 19. The toggle member 10 is extended to form a handle 20 by which the clamps may be manually closed. When the toggle members 9, 10 are straightened the bracket arm 13 will be forced downwardly. This downward movement will bring the lips 16,17 into engagement and thus swing the clamps downwardly in a wellknown way, the clamps being held clownwardly by the straightened toggle. The bracket arm 13 has a pulling spring 21 secured thereto which elevates the bracket arm 13 and frame 14 when the toggle is broken.

The clamps are automatically closed when the machine is started in a well known way through the medium of a lever 22 which is pivoted at 23 and is provided with a roll 24 adapted to be acted on by a cam surface 25 on the main cam 8.

The toggle arm 9 is provided with a lateral extension 26 situated to be engaged by the end of the lever 22 when the latter is depressed by the cam 25, the engagement of the lever 22 with the arm 26 serving to straighten the toggle as will be readily understood and thereby closing the clamps. This operation occurs as soon as the machine is started.

The machine herein shown is also provided with means for cutting the buttonhole. In the construction shown this comprises a buttonhole cutter 27 and an anvil or bed member 28 which is mounted on an arm 101 pivoted to the frame 7. This arm 101 is controlled by the usual main cam 8 andwhen it is depressed it forces the work down onto and over the buttonhole cutter 27 thereby to cut the buttonhole slit.

The parts thus far described are or may press thelever 22 thereby causing 5 io'ccurs subsequent to thesewing oper he'all as usual in sewing machines of this type, exemplifications of whlch maybe found infinited States Patents No. 1,352,280, Sep-[ tember 7th, 1920, and No. 1,558,182, {)ctober, th,1925. Q

--.The operationot the machine, except for;

the thread-trimming devices, is in general as follows. brought to rest at the end of a sewlng oper- 19! ation the cam 8v will be so situated that "the cam pro ect1on is immediately ad acent the roll 24 and when the machine is started in operation the first or initial movement of the A cam 3 will cause the cam projection-25m de toact against the arm 26 and straigii toggle 9, 10 to close the clamps onto'jthe work 1. The stitching then proceeds down one side ot the buttonhole and back along the other 9; side, there belng a relative movement between the stitch-forming mechanism and the workholding means during the stitching along the sides of the buttonhole' and theturret 29 having a turning movement at the ends of the 5*buttonliole. When the sewing operation is completed the parts will be in substantially the position shown in Fig. 8, one end of the buttonhole 32 which has been sewed being d1- J C 1 rectly over the throat plate 31 and Ji or Q1being still clamped by the worl: clamps .Atter the stitch-forming mechanism has come to-rest then'the work-holding means and stitch-forming mechanismare given a relative movement by which the worlr is rclaftively-carr1ed to tllGPOSltlOIl shown in Fig.

9, the buttonhole 32 being brought position over the cutter 27. and in position to beiactedon by the cutter block 28. VJhen the stitch-forming mechanism comes to rest e read-manipulating i'nechanisnr and wh the relativemovement between the stitchf0 ingmechanism and work-holdingmeans such, relative movement will draw out at nlate,'such length 'comprising an elon- .ion ot the loop 33 of needle thread. 34

isused, and a length of stay cord 36 it stay cord is used. These threads whiclarc thus drawn out Wlll .liealong under the work of v a p l 5Qilength of under thread 35,1fan under threa indicated by dotted lines at 37'infFigi for its object to pr the thread or threads 37 which extend the work to the throat plate after the work has' heen carried relatively into buteonhole cutting position, The threads normal y lie ..iclosely adjacent to the. work and Whenever the machine has been.

plane parallel to the ere will be'a loop 33 ot'the upper thre d retained by the loopers ot the u .d

gth of threador threads through the through which the threads extend.

G3 evel. meanstor cutting close to theworkf tially parallel thereto and in order to cut or trim the threads in a sure and satisfactory manner I provide a pulledown device which operates to pull the threads indicated by the dottd lines 37 in Fig.9 downawayfrom the worl: l as shown in tulllines Fig. 9 thus separating the threads from the work and bringing thethreads into position tobe acted on by the cutter which. cuts, the thread between the pull down and thework.

- pull-down herein shown comprises two thread-gr pping fingers 38 and39 which are mountedv to move toward each other in a the threads between them and-then have a downward sw ngin movement to carry the threads awayfrom the work 1. These pull-x downfingers are pivotally mountedfat t2 on the bed Each arm isprovided witha oam slot, said slots being indicated at 43 and i irespectively. These slots receive M011 45 mounted on an arm d-tipivoted to the-bed at, The rear end of the slots 43,414 are hi ed r-lativo to each otherand' arefso,

i. g l. that a swinging movement of the -rm :6, causes tne arms 40,41 to-swing-toward and from each other.;

During the sewing operation the parts are in the position shown in Fig. 2 and the pull- 1 downfingers will be separated from each other. After the sewing operation-is completed and during the relative movcmentbe work and therebygrip tween the stitch-forming mechanism and ework-holding means by which the parts are carried to hut-tonhole cutting position. and

the length, of thread is drawn through the throat plate 31 as shown at 37, the arm 46, is swung forwardly into the position shown in 3 thereby acting through thecam slots 43, .464: to swing the arms 40, 11 toward each other. During this movement the lengthot thread which has been drawn out is rasped by the twopull-down fingers.

it will be noted that each pull-down finger.

is provided at its end with a thread-receivin g notch 1-8 and that the pull-down finger. 38 has two extensions 49 while the pull-down finger 39 has the four extensions 50. These extensions are. adapted to have interlock engagement when the two pull-down fingers are-brought relatively into the position shown in Figs. 3'and 7' at which time the iengthoi threads are confined in the two notches 48.

The extensions 49 and 50 at this time have is positively retained in the aligned notches l8,1the two notches forming a sort of eye shape of the upper extension 49 is such that during the swinging movement of the pullg The;'

down fingers from the position shown in Fig.2 to that shown .in Fig. 7 said-upper.

extension 49 will findits Way between the length of thread andthe work andthus 120' I, an overlapping Ti /121M011 so. that the thread i guide the length of thread or threads into the notch 48.

After the two pull-down fingers have been carried into the position shown in Fig. 7 so that the threads are confined in the notches 48 then the ends of said fingers are swung downwardly thus separating the threads from the work. For this purpose the fingers are pivotally mounted to the arms 40, 41.

The finger 38 is shown as fast on a rock shaft 51 which extends longitudinally of the arm and is journalled in an elongated bearing 52 formed therein. The finger 39 is similarly fast on a rock shaft 53 which is aournalled in an elongated bearing 54 formed on the end of the arm 41. Both fingers 38, 89 are acted upon by springs 55 which nor mally hold them in their raised position.

For giving these pull-down fingers 38, 89 their downward swinging movement by which the length of thread or threads is separated from the work if have provided means which is actuated by the arm 46. It will be remembered that one end of the slots 43, 44 in the arms 40, 41 have an inclined relation to each other. The other ends 56 of the slots are so shaped that when the arms 40 and 41 are in the position shown in Fig. 8 the ends 56 of the two slots are in alignment with each other and are concentric to the pivot 47. Consequently during the initial swinging movement of the arm 46 the arms 40, 41, will be swung toward each other and during the final movement of the arm 46 the pin 45 will merely move in the concentric portions 56 of the slots and the arms 40, 41 will remain stationary.

Means are provided whereby during the final swinging movement of the arm 46 the pull-down fingers 38, 39 will be given their pull-down movement. For this purpose the arm 46 is shown as having a cam 57 thereon which is adapted to engage an arm 58 formed on the rock shaft 51. The cam 57 is so positioned that it engages the arm 58 just as the roll 45 reaches the concentric portions 56 of the slots and, therefore, during the final swinging movement of the arm 46 the cam 57 will engage the arm 58 and thus rock the shaft 51 in a direction to swing the free end of the pull-down finger 38 downwardly. Since the two fingers .are interlocked or geared together by the extensions 49 and 50 the downward swinging movement of the finger 88 will be communicated to the finger 39, the rock shafts 51, 58 constituting the aXes about which the fingers turn. By this operation the length of thread, which is indicated at 87 in Fig. 9 which extends between the throat plate 31 and the sewing point, is pulled down away from the work as shown by full lines Fig. 9 thus placing the thread in position to be acted on by thread cutters. These thread cutters are indicated at 59, 60 and they are mounted on swinging arms 61, 62 that are pivoted to the bed at 63,

64, respectively. The arms operate in planes parallel to the work and are adapted to swing from their open position shown in Fig. 3 to their closed thread-cutting position shown in Fig. 4. This swinging movement of the thread cutters by which the thread is cut occurs after the thread has been pulled down as shown in full lines Fig. 9, said cutters acting on the pulled down thread close to the work.

While any approved means may be employed for operating the pull-down fingers and the cutters T have herein shown a construction wherein the pull-down fingers are actuated by the movement of the turret which occurs after the sewing has been completed and the thread cutters are actuated by the means which are employed to unclamp the worn or release the clamps 4. For operating the pull-down fingers from the turret I have secured to the turret a cam extension 65 having a cam groove 66 and the arm 46 has rigid therewith another arm 67 provided with a roll or follower 68 adapted to operate in said groove 66 as the turret moves. The arms 46 and 67 are both shown as rigid with a rock shaft 47 which extends through the bed so that they operate as a unit. The cam groove 66 is open at both ends and the parts are so arranged that during the final relative feeding movement between the stitch-forming mechanism and work-holding means the turret will be so positioned that one end of the open cam groove 66 is in line with the follower 68 as seen in Fig. 2.

After the sewing operation has been completed and the stitch-forming mechanism has been brought to rest then during the further relative movement between the stitch-forming mechanism and work-holding means by which the parts are brought to buttonhole cutting position the follower 68 enters the end 69 of the cam groove 66 and as the turret is moved forward by the forward movement of the frame 7 by which the parts' are brought relatively to the position shown in Fig. 9 the follower 68 is carried through the cam slot 66 to the point 70 and during its travel through this cam slot the arm 46 is swung thereby to close the pull-down fingers together as shown in Fig. 3 and then to cause the cam 57 to engage the arm 58 and thereby produce the pulling down motion of the pulldown fingers 88, 39. As the follower 68 completes its travel. through the slot 66 orfrom the point 70 to the point 71 the arm 46 will be swung in the opposite direction thereby positively opening the pull-down fingers away from each other and restoring them to their normal position. This operation occurs after the threads have been cut and durin g the turning movement of the turret which follows the forward movement of the frame 7. 103 is a spring acting on the arm 67 and tion; Thus the travel ofthe follower from 'theiend 69 ofthe cam to the point7O will cause the pull-clown fingers to first move toward each otherto'grip the thread and then swing downwardly to pull the thread away from the work as above described and the re verse movement of the arm 46 caused by the travel of the follower 68 from the point 70 to the end 71' of the cam willreturn the pulldown fingers to their normal position shown in Fig. 2.- I

After the thread has been pulled down then the cutters 59, 60 are operated to cut the pulled down thread between the pulldown fingers and the work. are actuated in conjunction with the means for releasing the clamps and are given their cutting movement immediately after the clamps are'released; Both the cutter and the clamp-releasing means are controlled by the cam 8. w Thecutter-carrying arms 61, 62 are provided'with extensions 72, 7 3 and'these ex- 25 tensions are connected by a toggle device comprising the two togglemembers 74, 75 which are pivoted to the extensions at 76 and -77 and are pivoted-together at 78. The togglememher 75 is provided with an extension 80 81 which haspivotally connected thereto one end of a link 82, the'other end of said link being pivoted at 83 to a rocking member 84.

This member 84 is-pivotallymounted at 85 to the bracket arm 13.'

During the sewing operation and while the clamps are closed by the straightened toggle 9,10 the rocking member 84- occupies the position shown in 1,'it being held in this position by a pulling spring86 'whichis conend to the connection 82. Just after the pulldown fingers have been operated to pull down the thread, as shown by full lines Fig. 9, the member 84 is given a turning movement about its pivot 85 into the position shown in Fig. 6. This turning movement accomplishes two things.

swings the cuttersinto thread-cutting position'thereby to out the thread.

The member 84 is provided with a roll 87 which engages the toggle member 9 as the clamp-releasing member swings into the position shown in Fig. 6, such engagement 0D- erating tobreak the toggle 9, 10. which will, of course. release the clamps 4 in a well known way. This swinging movement of the member 84 also operates to draw the connection 82 to the left Fig. 1 into the position shown in Fig. 6 and since this connection is secured to the toggle member v7'5 such movement "of the connection 82 will partially straighten the toggle 74, 7 5'as shown in Fig. 4 thus swinging the thread-cutting members 65 59, 60 toward each other. This swinging desired construction. These cutters nected at one end to the bed and at the other;

It releases the Clamp. 4 by breaking the toggle I9, 10, and it also movement'is in a plane parallel to the work and since the pull down pulls the thread down so that the thread extends from the pull down upwardly to the work thecutters while swinging in this horizontal plane act on the thread between the pull-down and the work as indicated inFig. 9 and thus cut the threads close to the work; The threads- Which are out are all those whichextend from the work to the throat plate and will includethe two sides of the loop 33 ofthe needle thread andthe under thread 35 and the cord 36, if such under thread and cord are used.

The cutting members 59, may have any As herein shown 60 represents a cutting block and 59a cutter operating against said block, this construction being one which ensures positive cutting of the thread because of the toggle lever ac tion by which the arms 61, 62 are actuated.

The member 84 is given its movement by means of the lever 22. For this purpose said lever has extending therefrom a pin or projection 88 adapted to engage a shoulder 89 formed on the member 84.

The main cam 8 is provided with a cam surface 90which is situated so that it will engage the roll 24 on the lever 22 just after the pull-down fingers have operated to pull down the length of thread as shown in Fig. 9. As the cam surface 90 rides onto the roll 24 the lever 22 will be depressed, such depressing movement causing: the projection 88 to act on the shoulder 89 and thereby swing the member 84 into the position shown inFig. 6.

Therise of thecam'projection 90 is such as to give the lever 22 sufiicient downward movement to causeit to wipe by theshoulder89 and as'a result the cutters will be given a quick cutting movement and then will be releasedand returned to their normal position.

For ensuring the return of the cutters to their normal position the toggle 74 has rigid therewith an arm or extension 79 having at its end a roll 80 and the turret is provided with a cam surface 104 situated to engage the roll 80 as the turret isturned after the frame 7 has completed its forward movement. The

engagement of the cam surface 104 with the a roll 80 will break the toggle 74, 7 5 and thus positively open the cutters away from each other. l 105 indicates an adjustable 7 stop screw which may be employed to limit the straightening movement ofthe toggles 74,7 5 thereby to prevent undue pressure or strain from coming on the arms 61, 62.

The construction of the swinging member 84 and the toggle arm 9 is such that the first swinging movement of the member 84 will release the clamps and further swinging movement will actuate the cutter. The arm 9 is shown as-having a curved surface 106 which is concentric with the pivot 85 when the swinging movement of the clamp-releasing member 84 and the clamps have been released then during further swinging movement of the member, 84: the roll 87 will move over the concentric surface 106 and thus such furt-her swinging movement will not afiect the toggle.

It will be further noted that the polnt of connection 83 of the link 82 with the swinging member 84 is such that when the cutters are brought into cutting position as shown in Fig. at the member 83 is nearly in line with the pivot 85 and thus a maximum cutting force will be applied to the cutters and positive cutting of the thread will be ensured.

The machine comes to rest finally with the roll 24 resting on the surface 91of the cam 8 between the cam projections and 25 and thus the lever '22 is in position to act on the arm 26 to close the clamps when the machine is again started in operation.

It will thus be seen that the clamps 4; are released before the threads are cut. The cam for operating the cutter block 28, however, is so timed that said cutter block is closed down onto the work just before the thread is cut so that at the time the threads are being cut the work is being gripped between the block 28 and the buttonhole cutter 27. As the cutter block has its complete downward movement it forces the work down over the cutter as shown by dotted lines 107, Fig. 9 and this has the advantage that it places the work in more advantageous position for the cutting of the threads. Hence although the work clamps 4 are raised from the work during the thread cutting operation yet the work is held between the buttonhole cutter 27 and the cutter block 28.

The under thread 85 extends up through the hollow tube 92 situated axially of the turret and from the latter passes over suitable guides to a tension device 98 comprising two spring-pressed tension disks between which the thread is led. From the tension disk the thread extends up through an eye 108 on the end of a spring tension finger 109 and thence passes to the under thread mechanism 99. During the sewing operation the yielding finger 109 will have a varying position but will be frequently in the position shown in dotted lines Fig. 5.

During the movement of the parts from stitching to buttonhole cutting position and while the thread is being pulled off the strain on the under thread will straighten the finger 109 so that the thread will be led from the tension to the under thread mechanism as shown by full lines F i g. 5. When the threads are out the resiliency of the spring arm 109 will.

cause it to move into the dotted line position Fig. 5 and in so doing a length of the under thread will be pulled from some source. If

the tension 93 is still applied this movement of the spring arm 109 from the full to the dotted line position will draw the under thread back through the throat plate and will thus leave insufficient length of under thread [5% to properly form the first stitch at the'next stitching operation.

I have, therefore, provided means to :pre-

vent this from happening. Onesu'ch means is shown in Fig. 5 wherein a device is .iliustrated for relieving the tension 93 on V the thread ust before the thread is cut and after a length of thread has been pulled through the throat plate so that before the thread is cut the resiliency of the arm 10.9 in swinging (f 0 from the full to the dotted line position Fig. 5 will draw on the thread from the source of supply. This tension-releasing device is in the form of a tension-releasing lever '94 pivoted to the turret :at 95 having a wedge $5 shaped end 96 adapted to enterbetween the tension disks and separate them. This sion-releasing lever 94 is normally held in its inoperative position as shown in full lines Fig. 5 by the spring 97 and said lever is pro-2. 5 vided with an extension 98, the upper end of which is confined in a slot in the cam extension 65 and normally occupies :a position within thecam groove 66. As the foilower 68 traverses through the cam groove 66 it en-" gages the upper end 98 of the lever :94 swings the latter into the d-otted line position thus causing the wedging 11 ortion 96there0f to separate the tension disks and thus relieve the tension on the under thread 35. This occurs 7 before the thread is cut and hence after the thread is out there will be no unusual tension on the under thread tending to pull it back through the throat plate. 7

Another device for accomplishing this is shown in Figs. 1'0 and 11. in this embodi- 'ment of the invention the cam member 65 has pivotallymounted thereon at an arm 111 which is provided with a cam portion112 that overlies the cam groove 66 so that as the follower 68 passes through the cam groove 66 it engages the cam surface 112. The arm is provided with a curved end 113 situated adjacent the resilient finger 109. The arm 111 is acted on by a spring 114 which normally Q15 holds it in the full line position Fig. 11. As the follower 68 passes through the cam groove 66 and engages the cam surface 112 the arm 111 will be swung from the full to the dotted line position and in so doing will force the 3331 arm 109 positively b ackwa-rdly to the dotted line position Figs. 5 and 11 which is its normal position when no strain is applied to the thread. This occurs while the thread is be ing pulled off and the arm 111.,therefore,holds the thread take-up arm 109 in its backward position while the thread is being pulled ofl' and thus compels the thread to be drawn through the tension at this time. Therefore, H p the arm 109 is in its backward position shown While I have illustrated herein a selected embodiment of my invention I do not wish to be limited to the constructional features. shown.

I claim:

1. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism and work-holding means movable relative to each other during and subsequent to the stitching operation, of a throat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, means to separate said thread from the under side of the .work, and other means operating independently from the last-named means to cut the thread close to the work.

2. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism and work-holding means movable relative to each other during and subsequent to the stitching operation, of a throat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, means to engage the thread between the throat plateand the work and carry it away from the work,

and other means operating independently from the last-namedmeans to cut the thread close to the work. 7

3. In a sewing machine adapted to per form a predetermined sewing operation and then come torest, the combination with stitchforming mechanism and work-holding means movable relative to each other during and subsequent to the stitching operation, of a threat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, a pull-down to engage said length of thread and separate it from the work, and other means to cut the thread close to the work.

4. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism and work-holding means movable relative to each other during and subsequent to the stitching operatiornof a throat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, means to separate said thread from the under side of the work, and a cutter operating indepei'idently of said last-named means and in a plane parallel to the work to cut the thread close to the-work.

a I 5. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism and work-holding means movable relative to each other during. and

subsequent to the stitching operation, of a throat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, means to enthe thread between the threat plate and the work and carry it away from the work, and a cutter operating independently of said last-named means and in a plane parallel to the work to cut the thread close to the wor 6. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch- I forming mechanism and work-holdingmeans movable relative to each other duringand subsequent to the stitching operation, of a throat plate through which thread is led to the work, the relative movement after the stitching operation drawing out a length of thread from the throat plate, a pull-down to engage said length of thread and separate it from the work, and a cutter operating in a plane parallel to the work to'cut the thread close to the work.

7. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitchforming mechanism, of work clamps for clamping the work, said stitch-forming mechanism and work clamps having a relative movement at the completion of the sewing operation to draw off a length of thread, a pull-down acting on said length of thread to separate it from the work, clamp-releasing mechanism, and means actuated thereby to cut the thread between the pull-down and the work.

8. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch-forming mechanism, of work clamps,

said stitch-forming mechanism and work clamps having a relative movement at the completion of the sewing operation to draw 05 a length of thread, means to separate said length of thread from the work, other means to trim the thread at the end of the sewing operation, and means actuated thereby to release the clamps.

9. In a sewing machine, the combination with work-clamping means, of stitch-forming mechanism, said work-clamping means and stitch-forming mechanism having a relative movement at thecompletion of the sewing thereby to draw oil a length of thread, a pull-down to engage said thread and separate it from the work, clamp-releasing means,

clamped.

' 10. Ina sewing machine, the combination with work-holding means, of stitch-forming mechanism including a needle operating above the work, under-threadmanipulating mechanism operating beneath the work, a turret on which the under-threadmanipulating mechanism is mounted, said stitch-forming mechanism and work-holding means having a relative movement after the completion of the sewing by which a length of thread is drawn out, means operated by the movement of the turret to separate said length of thread from the work, and means to cut the thread.

11. In a sewing machine, the combination with work-holding means, of stitch-forming mechanism including a needle operating above the work, an under-thread-manipu lating mechanism operating beneath the work, a turret on which the under-thread manipulating mechanism is mounted, said stitch-forming mechanism and work-holding means having a relative movement after the completion of the sewing by which a length of thread is drawn out, means operated by the movement of the turret to separate said length of thread from the work, and a thread cutter for cutting the thread, which thread cutter operates in a plane parallel to the work.

12. In a sewing machine, the combination with work-clamping means, of stitch-torming mechanism including a needle operating above the work and underthread-manipulating mechanism operating beneath the work, said work clamps and stitch-forming mechanism having a relative movement at the completion of the sewing operation by which a length of thread is drawn out, clampreleasing means, means acting on said length of thread before the clamps are released to separate the thread from the work, and means to cut the thread after the clamps are released.

13. In a sewing machine, the combination with work clamps, of stitch-forming mechanism including a needle operating above the work, an under-thread-manipulating mechanism operating beneath the work, a turrret on which the under-thread-manipulating mechanism is mounted, said work clamps and stitch-forming mechanism having a relative movement subsequent to the sewing operation thereby to draw out a length of thread, clamp-releasing means, means operated by the movement of the turret to separate said length of thread from the work, and means to cut the thread after the work is unclamped.

14. In a sewing machine, the combination with work clamps, oi stitch-forming mechanism including a needle operating above the work, an under-thread-manipulating mechanism operating beneath the work, a turret on which the under-thread-manipulating mechanism is mounted, said work clamps and stitch-forming mechanism having a relative movement subsequent to the sewing opera tion thereby to draw out a length of thread, clamp-releasing means, means operated by the movement of the turret to separate said length orthread from the work before the clamps are released, and means to cut the thread after the work is unclamped.

15. In a sewing machine, the combination with work-clamping means, of stitch-forming mechanism including a needle operating above the work and under-thread manipulating mechanism operating beneath the work, said work clamps and stitch-forming mechanism having a relative movement at the completion of the sewing operation by which a length of thread is drawn out, means acting on said length of thread before the clamps are released to separate the thread from the work, other means to cut the thread, and means actuated thereby to release the clamps.

16. In a sewing machine, the combination with work clamps, of stitch-forming mochanism including a needle operating above the work, an under-thread-manipulating mechanism operating beneath the work, a turret on which the rmder-thread-man'ipulating meeh anism is mounted, said work clamps and stitchforming mechanism having a relative move ment subsequent to the sewing operation thereby to draw out a length of. thread, means operated by the movement of the turret to separate said lengthof thread from the work. means to cut the thread, and means actuated thereby to release the clamps.

1?. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch-forming mechanism, of work clamps, a main cam controlling the operation of the machine, means actuated thereby to trim the thread at the end of the sewing operation, means actuated by the thread-trimming means to release the clamps but before the thread is trimmed and means other than the clamps for holding the work while the thread is being trimmed.

18. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination witl workclamping means, of stitch-forming mechanism. said work-clamping means and stitchforming mechanism having a relative movement at the completion of the sewing thereby to draw oil a length of thread, a pull-down to engage said thread and separate it from the work, a thread cutter to cut the thread between the pulldown and. the work, threadv a plane parallel to the work to cut the thread nism, said work-clamping means and stitchformin'g mechanism having a relative move-- ment at the completion of the sewing thereby to draw olla length of thread, a pull-down to engage said thread and separatej'it from the work, a thread cutter to out the thread between the pull-down and the work, threadcutter operating'means, and means actuated thereby torelease the clamps prior to the cutting of the thread.

20. In a sewing machine, the combination with work-holding means, stitch-forming mechanism including a needle operating above the work, an under-threadmanipulating mechanismcarrying an under thread, a turret on which the under-thread-manipulating mechanism is mounted, a-thro'at plate carried by the turret and through which the under thread passes to the work, a'resilient take-up finger carried by the turret and through which the under thread passes, said stitchiorming mechanism and work-holding means having a relative movement after the completion of the sewing by which a length of thread is drawn out through the throat plate, means to out said thread'between said throat plate and the work, and means operated by the movement of the turret toengage said finger and hold it from flexing movement while the thread is being drawn out.

21. In a sewing machine, the combination with work-holding means, stitch-forming mechanism including a needle operating 35 above the work, an under-thread-manipulating mechanism carrying an under thread, a turret on which the under-thread-manipulating mechanism is mounted, a throat platecarried by the turret and through which the under thread passes to the work, a resilient takeup finger carried by the turret and through which the under thread passes, said stitchforming mechanism and work-holding means having a relative movement after the completion of the sewing by which a length of thread is drawn out through the throat plate, a tension for the under thread carried by the turret, and means operated by the movement of theturret to relieve the tension on the under thread whilesaid thread is being drawn out through the throat plate.

22. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch-forming mechanism and work-holding means movable relative to each other subse close to the work.

23. In a sewing machine, the combination with work-holding means, of stitch-forming mechanism including a needle operating from above the work, thread-manipulating mechanism operating beneath the work,,a turstitch-forming mechanism and work-holdret on which said mechanism is mounted, said ing means having a relative movement after the completion of the sewing by which a length of thread is drawn out, non-cutting means operated by the movement of thetur- I net to separate said length of thread from the work, and means to cut the thread. V 24. In a sewing machine adapted to perform a predetermined sewing operationand then come to rest, the combination with stitchforming mechanism including a needle operating above the work and under thread mechanism beneath the work, of work-holding means, a turret on which the under thread mechanism is mounted, said stitch-forming mechanism and-work-holding means having a relative movement after the completionof i V the sewing by which a length of thread is drawn out, a main cam controllingthe operation ofthe machine, means: operated by the movement of the turret to separate said length of thread from the work,'and means I actuated by the cam'to cut the thread.

25. In a sewing machine adapted toperform a predetermined sewing operation and then come to rest, the combination with stitch-forming mechanism including a needle operating above the work and under thread mechanism' beneath the work, "of work-holding means, a turret on which the under thread mechanism" is mounted, said stitch-forming mechanism and work-holding s means having a relative movement after the of thread is drawn out, a main cam cont-rolling the operation of the machine,'non-eutv ting means operated by the movement of the turret to separate said length of'thread from the work, and means actuated by the cam to cut the thread. i

26'. In a sewing machine,.the combination the work'and under thread mechanism beneath the work, a turret onwhichthe'under thread mechanism is mounted, said workfclamping means and stitch-forming mecha 'nism having a relative movement at the completion-of the sewing operationby which a with work-clamping means, of stitch-fo'rming means including a needle operatmg above length ofthread'is drawnout,clamp releas V I ing means, means actuated by the=turret to separate said length ofthread from'the work before-the clamps are released, and means to cut the thread after the clamps are released. 27.]In a buttonhole sewing machine, the

combination with work-clamping means, of.

its

I00 completion of the sewing by which a length 7 9 stitch-forming mechanism and work-holding ting means movable in a diflerent direction 28. In a buttonhole sewing machine, the combination with stitch-forming mechanism, .of worleclamping means, and means operative at the end of the sewing operation first to release the clamps, then to trim the thread and then to cut the buttonhole.

29. In a buttonhole sewing machine, the combination with stitch-f0rming mechanism, of work-clamping means, a thread trimmer, a buttonhole cutter, means to release the clamps at the end of the sewing operation and subsequently to actuate the trimmer, and means to actuate the buttonhole cutter to cause it to grip the work while the thread is being trimmed and thereafter to out the buttonhole.

30.. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with means movable relative to each other during and subsequent to the stitching operation, of a throat plate through which a thread is led to the work, the relative movement after the stitching operation drawing out a length of then come to rest, the combination with stitch-formingmechanism, of work clamps, said stitch-forming mechanism and work clamps being movable relative to each other during and subsequent to the stitching oper- 1 thread from the throat plate, non-cutting means movable downwardly at substantially right angles to the work to separate said thread from the under side of the work, other means movable in a different direction to cut the thread close to the work, andmeans to operate the non-cutting means and the cutting means successively.

31. In a sewing machine adapted to perform a predetermined sewing operation and then come to rest, the combination with stitch-forming mechanism, of work-holding means, said stitch-forming mechanism and work-holding means having a movement relative to each other at the end of the sewing operation thereby to draw out a length of thread, non-cutting means movable downwardly in a direction substantially at right angles to the work to separate the thread from the under side of the work, and threadcutting means movable in a difierent direct1on to cut the thread close to the work.

32. In a sewing machine adapted to perform a predetermined sewing operation and then come to, rest, the combination with stitch-forming mechanism, of work-holding means, said stitch-forming mechanism and work-holding means having a movement relative to each other at the end of the sewing operation thereby to draw out a length of thread, non-cutting means movable downwardly 111 a direction substantially at right angles to the work to separate the thread from the under side of the work, thread-cutto out the thread close to the work, and means for operating the non-cutting means and the cutting means successively.

33. In a sewing machine adapted to perform a predetermined sewing operation and

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