US2508236A - Thread cutter and nipper for sewing machines - Google Patents

Description

. v. P. ENos THREAD CUTTER AND NIPPEE EGR SEWING MACHINES Filed March 21, 1947 lI5 Sheets-.Sheet l Wfl/Www s W.. 977% May m9 R95@ J. P. ENOS SQ@ THREAD CUTTER AND NIPPER FOR sEwNG MAcmNEs Filed March 21, 1947 s sheets-sheet 2 rllllgv'lllllll May E6, N5@ -J. P. ENOS THREAD CUTTER AND NIPPER FOR SEWING MACHINES Filed March 21.,I 1947 3`Sheets-Sheet 3 @Q3/Kwast patented May l16, 1950 Y "UNITED PS TAT/ES `18 Claims.

i `This invention .relates to .thread-severing d evices for sewing machines and is :particularly adapted for embodiment y-in'householdorl family types of sewing machines for the purpose of ssevering the'stitching threads connected to sewed articles A primary foibject of `the present invention is t'o .provide conveniently yoperable means, pret- "aerably in the-form o f an attachment, forrsevering the stitching threads, extending from asewed article, at a :predetermined distance .from the l stitching point, thereby .to insure 'that the 'requisite llengths tof threads are VVavailable :in l.the -isjewing machine to commence a succeeding stitching operation. When the lengths of the severed threads extending 4from the stitching point .are vtoo short, the .end of the needle thread will either be withdrawn through the eye of the needle, by the take-up, thereby 'unthreading the needle or it will be drawn 4downbelow the -work in the succeeding stitching operation-thereqby resulting in skipping .-oi stitches and .possibly also in clogging of the loop-taker of thelse'wi-ng machine. On the other hand, an excessive length of thread extending `from time stitching ypoint 1results 4in threadv wastage and .occasionally in `snarling of the thread. l g

.sA further objectof this invention `isfto pro- ;vide means, `which is rendered effective l-upon lseveringor the-stitching threads, for temporarily .holding the lsevered ends of the-threads extendl'in girorn the stitching point. -More lspecical'y, thepresent linvention laims to provide `means for holding the severed ends of Ythe ithreads 'until `one or more stitches have been made in a ysuc- .,.cee'dng sewing operation, which thread-holding means automaticallyreleasesl'the thread during -fthesucceedingsewing operation and also 'when v`the usual sewing machine presser-*foot is raised -for insertion and removal of work.

With the above and other "objects in view, .as `willhereinafter appear, 'the invention comprises fthe-devices, combinations, and Yarrang.er'nerits `of partshereinafter setforth and. illustrated in the accompanying -drawings of `preferredand modi- -edseinbodiments of the invention, from .which fthe-several vfeatures of the invention and the :advantages :attained thereby will Ybe readily understood by those Vskilled in ithe art. i :Inthedrawings:

Fig.: l is-,an end elevatiomon'an enlarged scale,

the dev-ice being shown in .carries vthe lower .-threadeseyering conventional Y .-mountedin the .bracket-arm ahead, for ,endwise --andpartlyinsection,rofitheimproved device. i

Fig. 46 -is .a -top .-,plan .view of 1a l.portion .of the clothgplateof the rinachiriaand of the ar; hih and *nipping blOGL Fig. I ris ra detaiLsectiQIlal View ...of nthe .complemental thread-severing .and nipping .elem ts, showing the 4movable blade in f-a position Lit oc.- cupies ,prior to Vits .ii-nal downwardmovemelit .anfd

lateral deflection into threadesevering relation with the stationary fblade.

Fig. 8 is a detailsectional view .of 'thecomplemental thread-severing and --nipping .elements yin the thread-severingvrelation thereof.

Fig. 9 is a view similar toEig. `'7,butshowing the complemental elementsfin .theinrelativeposi- `tion immediately rafter the thread has been .severed and whileitlisnipped. f'

Fig. Y1-0A is-an end elevation, onan enlarged. scale andY partly insection, cita fportionof` asevving..4L r4achine fitted with amodiiedf-form pf thefin'ven- .tion. y

Fig. llis a front elevation of themodicaion, also on an enlarged scale.

Fig. .12 is .a .rear elevation, :partly in section, also on :an enlarged scale, '.f .the -inodiiica on. with the thread-severing .and --nipping element shown in full lines, `in raised `.position andfin dotted lines, L in depressed position. Fig. .1S-,is aiplanviewcoi? theconstruction shown vin Fig. ,-lil, Iwith the ,presserbar linfsection.

'I Jhe invention vgisshownas .apliliedto ,a conventional typeoffamilysewing machine of which l designates a portion of .the-,bracketfarm'head in which is mounted, :for endwise verticalrnove ments, aneedle-'barl Wlihparriesin itsJnwer end, A aney-e1pointedtneedle. 3 Cooperating with lthe .needle 3, vin .the formation .of stitches, ,a lloopstaker., not shown. 'Also vertical A movement, is `a presser-band fitted #with a presser-foot .whichis-retained thereon by the usualclamp screw 56.

The machine-work-support'l, o f :which agp'ortion is shown in Figs. ."5 and ShiisfreCBSSe 13.0.31#- ceive athroat-.platef4 3,Y secured. byifasten'ing screws .55 9. The VVthroat-plate .provided .with the needle-aperture I and slots II in which latter operates a feed-dog I2, in the usual manner.

Secured to the lower end of the presser-bar, 4, by the presser-foot clamp screw 6, is the improved thread-severing and thread-nipping device comprising a supporting shank I3 having an upper and forwardly extending steadying arm I4 embracing the presser-bar 4 and the lower forwardly extending arm I5 apertured to receive the presser-foot clamp-screw 6 for securing the supporting shank on the presser-bar and against the shank of the presser-foot 5.

Integral with the supporting shank I3 is a laterally extending and vertically disposed supporting plate I6, on the `front face of which is pivotally mounted, by a shoulder screw I1, a handlever I8. This lever is spring-urged upwardly into retracted position by a spring I9 having a coiled portion embracing the pivot screw I1. One arm of the spring bears against the forwardly extending portion I4 of the supporting shank I3, while the other arm 2l thereof bears upwardly yagainst the under side of a forwardly extending thumb-piece 22 of the hand-lever I8.

Pivotally mounted at the rear side of the supporting plate I6, upon a shoulder screw 23, is an actuating lever 24, the free end of which is forked andV has its upper tine 26 contacting the outer surface of the closed upper end of an inverted U-'shalped thread-severing and -nipping member 26, of thin spring steel. The member 26 comprises a laterally yieldable thread-severing blade 21, having a sharpened cutting edge 21', and a laterally yieldable thread-nipping blade 28 having an unsharpened or rounded thread-engaging end 28'. The lower tine 25', of the actuating lever 24, is disposed between the blades 21 and 28 of the member 26 and in contact with the inner surface of the closed upper end thereof. 'I hus the lever normally urges the member 26 upwardly under the iniuence of the spring I9.

Motion is transmitted from the hand-lever I8 to the thread-cutter actuating lever 26, but in the opposite direction, through the medium of 'a shoulder screw 29 threaded into the lever 24 and having its shank passing through and engaging the walls of an inclined slot 33 in the handsevering blade 21 and urges it into contact with the side of the tine thereby preventing vibra- 'tion of the blade and insuring that it will be properly positioned relative to the cooperating ledger blade, later to be described.

Secured to and extending from the lower rear face of the plate I6 is a portion 33 forming, with .the plate I6, a rectangular guideway for the inverted U-shaped member 26 which provides the thread-severing blade 21, and the thread-nipping blade 28. The guideway is -wider than the spacing of the blades, thereby permitting the blades to move laterally and to center themselves with respect to a complemental stationary thread-cutting and -nipping member. Threaded into the outer wall of the guide-portion 33 is a thumb-screw 34 the free inner end of which contacts the thread-severing blade 21 during its downward movement, thereby preventing outward deflection of the upper portion of the blade. This causes the blade to be put under tension against the complementary stationary blade, thereby insuring a positive shearing of the thread as later will be described. A coil spring 35 embraces the screw 34 and bears upon the head thereof and upon the portion 33, thereby frictionally retaining the screw in adjusted positions.

Disposed beneath the thread-severing and -nipping blades is a lower complemental stationary thread-severing and -nipping element comprising a ledger-block 36, pivoted, by a rivet p, for slight turning movement, upon the free end portion 31 of a curved supporting arm 38 which, in turn, is adjustably secured upon the worksupport 1 by the fastening screws 39. The front edge 40 and the rear edge 4I of the ledger-block are spaced more widely apart than the normal spacing of the blades 21 and 28, as shown most clearly in Fig. 7, so as to insure a thread-shearing and -nipping action urpon the sewing thread t lying upon the block, when the blades 2 and 28 are depressed by the actuating lever 24. At its opposite ends, the block 36 is formed with `portions 36a, the upper surfaces of which are rounded and disposed within the normal plane of movement of the blades 21 and 28 and function to engage and spread the blades when they are depressed to sever and nip the thread. The slight pivotal movement of the block 36, under the thrust of the blades I1 and 28, causes it to be aligned with the blades in their downward movement.

The upper surface of the block 36 is milled off between the rounded end portions 36a, thereby affording a horizontally disposed channel 36b which receives the threads extending rearwardly from the stitching point and holds them in the paths of movement of the blades 21 and 28. The rear edge LlI of the block 36 serves as a stationary cutting edge which cooperates with the sharpened edge 21' of the movable cutting blade 21 in severing the thread.

A sheet metal housing 42, secured, by a screw 43, to an arm I6EL projecting rearwardly from the plate I6, aiords protection for the moving parts and prevents accidental contact therewith by the iingers of the operator.

It will be observed that the thread-cutting and -nipping device is located in the line of seam formation in rear of but closely adjacent the needle. The position of the device is such that the thread extending rearwardly from the needle, after a thread-cutting operation, is suiiicient to insure the beginning of the rst stitch of a succeeding stitching operation, without wastage of thread.

Forwardly of the block 36, the arm 38 is provided with a raised member or portion 38a having an inclined forward wall 38h. This, together with the fact that the ends of the member 38a and the rounded portions 36a of the block 36 are inclined upwardly, facilitates passage of the work to and over the block 36.

In practice, the thread-serving and -nipping blades are normally maintained in elevated position to afford a clear and unobstructed passage of the work beneath the same. At the completion of the sewing operation, the work is advanced slightly beyond the block 36 thereby causing the sewing threads to rest upon the block within the channel 36h. The operator then depresses the hand-lever I8 thus causing the thread-cutting and -nipping blades rst to be lowered into contact with the rounded portions 362' of the block 36, as shown in Fig. '1. It will be noted that, in this position, the blades 21 and 28 are in their normal or undeiiected condition and are located inwardly citheir complemental cuttingfand nipping edges H2 and 40, respectively, of theblo'ck 36. 'Further depression of the hand-lever I8 causes the lower eri'dsr of the'blades 2l and 28 to pass down over the `rounded end portions 36a of the block 35, thus deflecting the blades outwardly away from each other and bringing the cutting edge 2l into shearing relation with the edge 4l of the block 35, thereby severing the thread t as illustrated in Fig. 8.` Still further depression of the hand-lever I8 causes the blades 2l and 28 to descend to the positionV illustrated in Fig. 9, in which position the blade `28' nips the end portion t of the thread t between itself and the edge 49 of the block 35, thereby holding the thread end against movement toward the switch-forming mechanism during the formation of the rst stitch of the succeeding sewing operation.

The lateral pressure of the blades 21 and 28 on the sides of the block 3% will cause the blades to remain in the position shown in Fig. 9 after the thread has been severed and nipped. Upward movement of the presser-bar and presser-foot, either under the action of the usual presser-lifter, not shown, for removal or insertion of work, or the lifting thereof by the action of the feed-dog during the next succeeding work-feeding movement, will cause the member 2B, with its blades 21 and 28, to be elevated and freed from the block 36, whereupon the parts are returned to their retracted positions, as shown in Figs. 2 and 3, by the spring I9.

, A modified form of my invention is disclosed in Figs. 10, 11, 12 and 13. In these figures, the parts which are the same as Vthose shown in Figs. 1 ito 9, and above described, are designated by the ,53me reference characters. Further description of these parts is deemed unnecessary.

The modied construction comprises ,a supporting shank 44 secured to the presser-bar 4 by the usual presser-foot clamp screw 5. Shank 44 has a laterally off-set portion 45 (Fig. 13) to which is secured, by screws d5, a U-shaped guide member lll within which is slidngly mounted, for vertical reciprocation, an inverted U- shaped thread-severing and -nipping member 26 having a thread-serving blade 2l and a threadnipping blade 2t, as hereinbefore described in reference to Figs. l to 9, inclusive. Secured to the side walls of the member 4l, by screws 43, and closing the open side thereof, is a second member 49, U-shaped in cross-section. This member 49 affords a slideway `i`or a vertically disposed slide member '50 having, at its lower end, a laterally projecting finger-piece 5l, the shank 52 of which projects through a slot 53 in the lower portion of the back wall of the member 4Q.

Secured to the slide member 5c and projecting therefrom and located between the blades 2'! and 28 'of the member 2e are lower and upper pins 5i and 55, respectively. A coil spring 5B, located between the blades 2l and 28 of the member 2E and having its upper end projecting through an aperture Zla in the closed end thereof, has its lower Vend surrounding the pin 5d and its upper end surrounding a pin 5l, carried by the upper portion of the member d?. Thus the spring 5t normally maintains the slide member 5e in its uppermost position. Upward movement of the member 50 is limited by contact of the shank portion 52 of the finger piece 5i, with the upper wall 58 of the slot 53 in the member 49. (See Fig. 1l.)

vAs shown most clearly in Fig. 12, the pin 55 is located within andfengages the closed upper end h:af-thelmerrxber 2b. Therefore, upward movement The of the slide member 50; and; the pin 55 carridr;

thereby, lifts the thrcadseveringr and -nipping member to its retracted orV inoperative position shown in Fig. lofandiny full lines invFig'. l2.

The slide member 5l) also carries a screw 5,9.. the head ofI which overliesand is adapted to engage the outer surface orl the closed upper end ofv the member 26. Thus as the slide member .50' is depressed, in opposition Yto the spring 56, by pressure applied to the linger-piece 5|, the` screw 59 forces the member 26Y downwardly to perform the thread-severing and -nipping operations as above described in connection with the construction disclosed in Figs. 1 to 9, inclusive. Downward movement oft-he slide member 5!) is limited by contact of an inturned finger 6,0-, provided by the member 55, with a shoulder 6| provided on the rear wall of the housing member 41 (Fig. 11).

The modification disclosed in Figs. 10. to 13..Y in.- clusive functions, in its thread-severing and -nip. ping operations, the same as Vdoes the construction disclosed in Figs. Al to 9, inclusive, which has already been described herein. Detailed description of the operation of the modied construction is therefore deemed unnecessary.

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

l. A thread-severing device for sewing machines, comprising, an endwise movable and laterally yieldable thread-severing blade; and a complemental ledger-block having a cutting edge and spaced rounded blade-deecting surfaces merging with opposite ends of the cutting edge of said ledger-block, said blade-deflecting surfaces being positioned for initial engagement by said blade in the approach of said blade to said ledgerblock.

2. A thread-severing device for sewingy ma.- chines, comprising, reciprocable and relatively laterally-yieldable thread-severing and threadnipping blades; ledger-means providing laterally spaced thread-severing and thread-nipping edges complemental to said blades but out of the normal path of movement thereof; means for moving said blades into contact with said ledger means;

and guide means for laterally deecting said blades into coacting relation with the respective thread-severing and thread-nipping edges.

3. A thread-severing device for sewing machines, comprising, laterallyspaced and relatively laterally yieldableV thread-severing and threadnipping blades; a complementa] ledger-blockhaving a pair of edges spaced laterally fromA each other more widely than the normal spacing of lSaid blades; `means for moving said blades into contact with said ledger-block; and guide means for laterally spreading said blades into coacting relation with. said `edges el. A threadesevering device .for sewing machines, comprising, laterally spaced and relatively laterally yieldable thread-severing .and threadnipping blades; a pivotally mounted ledger-block having a pair of thread-severing and thread-nipping edges spaced laterally irom each other more widely than the normal spacing .of said blades; means for moving said blades into contact with said ledger-block; and means carried by said ledger-blockl and cooperating with said blades for turning the block to align `its edges with the blades and for laterally deflecting the blades into coacting relation with said edges.

5. In asewing machine having stitch-forming mechanism. work-feeding mechanism, and presserdevice including a presser-.bar and .a presser-foot carried thereby; a thread-severing asoazse and thread-nipping device comprising spaced apart and relatively laterally yieldable threadsevering and thread-nipping blades supported by said presser-bar and located in, and arranged transversely of, the line of seam formation; a ledger-block having thread-severing and threadnipping edges cooperating, respectively, with said thread-severing and thread-nipping blades; and means supported by the presser-bar for moving said blades into thread-severing and thread-nipping relation with said edges.

6. A thread-severing device for sewing machines, comprising, a U-shaped member providing laterally spaced and resiliently yielding blades; a complemental ledger-block provided with a pair of edges spaced laterally from each other more Widely than the normal spacing of said blades, said ledger-block being provided with upstanding portions having surfaces engaging said blades and spreading them into coacting relation with said edges; .and means for moving said blades into engagement with said ledger-block.

'7. A thread-severing device for sewing machines, comprising, a movable U-shaped member providing laterally spaced and resiliently yielding blades, one of said blades being sharpened to provide a cutting edge and the other of said blades having an unsharpened edge; and a complemental ledger-block having a thread-severing edge and a thread-nipping edge spaced from each other more Widely than the normal spacing of the edges oi said blades, said ledger-block being provided with spaced convex guide surfaces merging with said edges of the ledger-block and disposed in the path of movement of the edges oi said blades.

8. A thread-severing device for sewing machlnes, comprising, a supporting member pro.- vided with a guideway; a U-shaped member providingv laterally spaced and resiliently yielding blades movable in said guideway; a ledger-block provided with a pair of edges spaced laterally from each other more widely than the normal spacing of said blades, said ledger-block being provided with means for spreading said blades into coacting relation with said edges; adjustable means carried by said supporting plate for limiting the spreading movement of said blades; and means for moving said blades into engagement with said ledger-block.

9. A thread-severing device for sewing machines, comprising, a supporting member provided with a guideway; relatively laterally yieldable thread-severing and thread-nipping blades mounted for movement in said guideway; a handlever and an actuating lever oppositely directed and pivotally mounted upon said supporting member; a ledger-block; an operative connection with said hand lever for swinging said actuating lever; and an operative connection with said actuating lever for moving said blades into thread-severing and thread-nipping engagement with said ledger-block.

10. A thread-severing device for sewing machines, comprising, a supporting plate provided with a guideway; relatively laterally yieldable thread-severing and thread-nipping blades mounted for movement in said guideway; a handlever and an actuating lever oppositely directed and pivotally mounted upon opposite sides of said supporting plate; a ledger-block; an operative connection between said levers; and an operative connection between said actuating lever and said blades for moving the latter into thread-severing and thread-nipping engagement with said ledger- 11. In a Y sewing machine, in combinatlorn stitch-forming mechanism including a reciprocating needle; a feeding mechanism including a feed-dog; a presser device including a presser-- bar and a presser foot carried thereby; relatively laterally yieldable thread-severing and nipping blades supported for movement with said presserbar; ledger-means providing thread-severing and thread-nipping edges complemental to said blades; means for moving said blades into engagement with said ledger-means; and means including said feed-dog and presser-foot for releasing said blades from said ledger means.

12. In a sewing machine, in combination; stitch-forming mechanism including a reciprocating needle; spaced thread-severing and threadnipping blades disposed in the rear of said needle and extending across the line of seam formation; a complemental ledger-block extending across the line of seam formation and provided with a pair of edges adapted to cooperate, respectively, with said blades, and means for moving said blades into thread-severing and thread-nipping engagement with the respective edges of said ledger-block.

13. A thread-severing device for a sewing machine having a work-support, comprising, a reciprocable U-shaped member providing threadsevering and thread-nipping blades; a supporting member secured to said work-support; a ledger-block carried by said supporting member and provided with a pair of edges adapted to c0- operate, respectively, with said thread-severing and thread-nipping blades; a work-deflecting member carried by the supporting member in advance of said ledger-block for upwardly deflecting the Work over said ledger-block; and means for moving said blades into coacting relation with the edges of said ledger-block.

14. A thread-severing device for sewing machines, comprising, an inverted U-shaped member providing laterally resilient blades, one of said blades having a sharpened end; a ledgerblock provided with laterally spaced edges complemental to said blades; means for advancing said blades toward and slidingly past said edges, to sever and nip sewing threads extending over` said ledger-block; and yielding means for retracting said blades.

15. In a sewing machine, in combination, stitch-forming mechanism including a reciprocatory needle; work-feeding mechanism; a ledger-block disposed rearwardly of the path of needle reciprocation and providing substantially parallel thread-cutting and thread-nipping edges extending across the line of seam formation; an inverted U-shaped member providing laterally resilient blades having the ends thereof vsubstantially parallel to said edges of the ledger-block and normally spaced apart less than the Width of said ledger-block; means for endwise moving said blades toward and slidingly past said edges into ledger-block clamping position; and means brought into effective action by operation oi said Work-feeding mechanism for retracting said blades from said ledger-block.

16. A thread-severing and -nipping device for sewing machines, comprising, a U-shaped guide member; a second U-shaped member comprising laterally resiliently yielding blades movable within said rst guide member; a complemental ledger-block provided with a pair of edges spaced laterally from each other more Widely than the normal spacing of said blades; means for depressing said second U-shaped member into cooperative relation with said ledger-block; and means for returning said second U-shaped member to an inoperative position spaced from said ledger-block.

17. A thread-severing and -nipping device for sewing machines, comprising, a U-shaped guide member; a second U-shaped member affording laterally resiliently yielding blades movable Within said first guide member; a complemental ledger-block provided with a pair of edges spaced laterally from each other more widely than the normal spacing of said blades; means for moving said second U-shaped member into contact with said ledger-block and for spreading said blades into operative relation with the edges thereof; and means carried by said iirst U- shaped guide member for adjustably limiting the spreading movement of said second U-shaped member.

18. A thread-severing device for sewing machines, comprising, a xed U-shaped guidemember; an endwise movable U-shaped member comprising laterally resiliently yielding blades Y Number REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Name Date 1,765,493 Lutz June 24, 1930

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