US2867184A - Thread cutter - Google Patents

Description

Jan. 6, 1959 H. J. KLAPPER 2,367,184

THREAD CUTTER Filed March 17, 1958 HERBERT I \.A PPER. BY

ArroemsrS United States Patent THREAD CUTTER -Herbert J. Klapper, Brooklyn, N. Y., assignor to Superior Sewing Machine & Supply Corporation, New York, N. Y., a corporation of New York This invention relates to an improved thread cutting attachment for a sewing machine.

After a garment or other textile article has been fed rearwardly under the presser foot and needle of a sewing machine, it is necessary to cut the. thread trailing from the garment before the next garment can be fed through the machine. It is then customary to lift the garment and move it back to the front of the machine for further sewing operations or for stacking purposes. An important object of this invention is to provide an attachment for a sewing machine, whereby afterthe garment has been fed past the needle to the rear of the machine, the thread may be automatically cut merely .by moving the garment upwardly and then forwardly to the front of the machine. As a result, the improved attachment eliminates the need for any extra operation on the part of the operator in order to cut the thread.

Another important object of this invention is to provide a thread cutting attachment for sewing machines which has a cutting edge instantly ready for use at the conclusion of the sewing of the garment, but which is always protected so as to prevent the possibility of accidental injury to the operator.

Another important object of this invention is to provide a thread cutting attachment for sewing machines which also grips or holds the thread after it has been cut, thereby preventing the needles from becoming unthreaded and preventing the thread from becoming slack.

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to the machine is automatically held between turns of the spring. This eliminates any need for the operator to manipulate the thread prior to the sewing of the next garment.

Other objects and advantages of this invention will become apparent from the following description in conjunction with the annexed drawing, in which a preferred embodiment of the invention is disclosed.

In the drawing, Fig. l is an end view of a conventional sewing machine, showing ,the improved attachment mounted thereon, and showing by means of an arrow, the front-to-rear direction of feeding of the cloth underthe presser foot.

Fig. 2 is a view similar to Fig. 1, but showing the manner in which the cloth is moved, after completion of the sewing operation, so as to withdraw the cloth and at the same time out the thread.

Fig. 3 is a top plan view of my improved attachment.

Fig. 4 is a section on line 44 of Fig. 1.

Fig. 5 is a section on line 55 of Fig. 4.

Fig. 6 is a section on line 66 of Fig. 5.

Upon reference to the drawing in detail, it will be noted that it shows a conventional sewing machine having a casing 10, a depending presser foot 11, and 9. depending needle 12 and needle holder 13. These parts are all conventional and are accordingly not shown or described in detail.

Fig. 4 shows post 14 depending from casing 10, and the U-shaped presser fot shank 11a fixed to post 14 bymeans of screw 15 in the usual manner. As is well known, said post 14 may be raised and lowered within casing 10 so as to raise and lower presser foot 11.

Fig. 1 also shows cloth 16 being fed under the presser foot and needle and above the usual anvil 17, in a frontto-rear direction, as indicated by arrow 18.

The attachment 20 may be made of any suitable material, such as iron in scrap form, which is-bent to the This permits the next garment to be sewed with a minimum of delay.

In accordance with a preferred embodiment of the invention, the attachment consists simply of a bracket adapted to be mounted upon the presser foot of the sewing'machine and having an arm located rearwardly of the presser foot and above the cloth being fed from front-to-rear under the presser foot. The arm extends cross-wise of the direction of travel of the cloth, and a knife is mounted on the arm with the cutting edge of the nife located behind the rear edge of the arm. Also in accordance with said preferred embodiment, a spirally wound coil spring is mounted upon said arm with said arm and said knife extending through the bore of the coil spring. Said spring is mounted on the bracket so as to be maintained under compression, so as to hold its turns quite close to each other, but with sufficient spacing therebetween to permit the entry of thread between the successive turns.

In use, the garment is fed past the presser foot and under the knife, and is then lifted by the operator upwardly and over the knife and withdrawn to the front of the machine. Since the trailing thread is being pulled from the machine, the thread is thus automatically drawn through successive turns of the spring and against the cutting edge of the knife, so that the thread is automatically severed.

As an important feature of the invention, the spacing and tension of the spring is maintained, so that after the thread is severed, the end of the thread which leads back desired shape. Said attachment includes a bracket which is of angular shape and which also extends vertically. Said bracket has a horizontally and vertically extending frontarm 20a having any suitable opening so that it may be secured to the end face of presser foot shank 11a by means of the same screw 15 which is used to secure said presser foot shank 11a to the post 14. Rearwardly of presser foot shank 11a said bracket 20 has an offset arm 20b which extends vertically and laterally inwardly from bracket arm 20a. The inner end of offset 20b connects with a further bracket arm 200 which extends vertically rearwardly from offset 20b. The rear end of bracket arm 20c connects with a further bracket arm 21. This bracket arm 21 extends vertically and also extends laterally outwardly from bracket arm 200. Accordingly, said bracket arm 21 extends cross-wise of the direction of travel of cloth 16 and is located above the cloth. A knife holding flange 22 is integral with arm 21 at the upper edge thereof and extends rearwardly therefrom. Said flange 22 extends horizontally and is of a width approximately equal to the height of arm 21. Accordingly, it will be apparent that the bracket 20 may be readily formed by appropriately binding a metal strap.

A knife blade 23 is fixed to the lower face of flange 22, by means of a central rivet 24, or by any other suitable means. Said blade 23 is of slightly less length than the length of arm 22, but is of greater width, so that said blade 23 projects rearwardly of the rear edge of arm 22. The rear edge 23a of blade 23 is sharpened so that it may serve as a cutting edge for the thread.

Said blade 23 may be made of any suitable material and is optionally made similarly to a single edged razor blade.

A spirally wound coil spring 25 is mounted upon arms 21 and 22 with said arms 21 and 22 extending through asevgt's t the central bore of'spring 25.- The inner turn of spring 25 abuts arm 200 which serves as a stop. An aperture is formed in the outer end of arm 21, adjacent the outer side edge thereof, and the' outer end 25a of'sprin'g'25 is extended through saidaperture. Said spring 25 is held under compressionwith its successive turns fairly close to each other. 7

By reason of the location ofthe end-25a ofspring 25 within the aperture at the lower outer corner of arm 21, spring 25 may be maintained with the lower edge of arm 21 adjacent the spring and with the knife edge 23a adjacent the spring. This reduces-the necessary movemerit of the thread'within the turns of the spring, in order that the thread may becuti a .Fig. 2-shows the manner in which the attachment may be used to cut thread. Fig. 2 shows the cloth 16 having a line of stitching 161 formed bythread 30. As shown in Fig. 2, after theclothr16 has completed itsrearward travel past needle '12, the thread, 30 which isbeing fed' from the machine in theusualmanner '(not shown) trails the cloth 16 and will continueito be pulled from the machine as the cloth is being withdrawn, unless the thread 30 is cut.

As shown in Fig. 2, the cloth 16 is moved upwardly behind the attachment and then forwardly over and past the attachment to a position such as that shownrin Fig. 2. In this movement, the. thread 30 is automatically drawn behindand over the attachment as shown in Fig. 2 and as shown in the detailed View ofFig. 5. In this way, the thread 30 passes between successive turns of spring 25 and against knife edge 23, whereby the thread is severed at thatpoint.

Preferably, the spacing between successive turns of spring 25.;is just sufficient for easy entry of the thread therebetween. However, at alLtirn'es the spring serves, as 1a, guide for the knife. and prevents accidental injury to the operator. Furthermore, in view of the spiral wind ing of thespring, the wire thereof serves cammingly'to guide. the thread between successive turns, so that even if the thread is drawn rearwardly at an angle to the longitudinal direction, it will still spring readily between the successive turns into engagement with the knife edge.

Fig. 5 shows the thread 30 having a portion 30a below the knife cutting edge 23:: and a portion 301) above knife edge 23a. The thread portion 30a leads back to the needle 12 and ultimately to the bobbin,,and the portion- 30b connects with the garment. The thread 30 extends frictionally slidably between successive turns of spring 25. When the thread is severed by knife'edge 23a, the thread portion 30b is drawn upwardly with garment 16. However, the thread portion 30:: is held frictionally between the turns of spring 25 and cannot fall free unless it is pulled clear by the operator. This eliminates any possibility of needle. 12 becoming unthreaded, and also maintainsqthe threadunder the proper tension. As a result, the operator can begin immediately to sew the next garment without any manipulation of the thread.

It is importantin the design of this attachment that the tension of the spring be such as to, permit relatively easy entry of the thread between turns of the spring, for the cu tting operation, whileat, the same timeholding the thread portion 30a frictionally between the turns after thev thread has been cut.

It will be apparent that-with the use of this attachment, no extra movements or operations on the part of the operator arenecessary to cut the thread after the garment has been sewn, since'the thread is cut automatically when the operator rnoves the garment upwardly and forwardly in the usualmanner, after completion of 1 machine comprising abracket having an arm adapted to e the sewing. operation, ,for withdrawal of the garment,

from the machine. 1 1

It will also be apparent, that withthe use of this attachment, no extra movements or operations on the part of the operator are necessaryito manipulate the thread after it has been cut and prior to sewing of the next garment, becausethe thread is held'automatically under tension between the turns of the spring after the thread has been cut.

While. I .have. -disclosedza preferred .embodiment. .of my invention and havetindicated various changes, QIIliSr, sio'nsgand additionswhichrnaybe made. therein, it, will be. apparent; thatvariouschanges, omissions or additions,

may be madethereln without departing from the scope and spirit thereof.

In particular, while the attachment is shown as used; witha singleneedle sewingmachinejit will be apparent that the attachment, maybe used in conjunctionwith other types of sewing machines. .Inparticular, the attachment is particularly suitable for use in conjunction wi h a ouble ee le a loo-k. Stitch. I

, Whatis. c a med t;

A thread cutting and holding attachment for a. sewing;

sewing machine which produces be mounted upon the. presser foot-of said sewing machine: so as to extend rearwardlytherefrom, an elongated blade having a majorv blade axisandwmounted upon said arm soas tov extend transversely of said arm and so as to overlie the path of movementof. clothing fed rearwardly under said presser foot during; the operation of said sewing, machine; said blade having a rear cutting edge extending parallel to said axis, an elongated compression coil spring having a spring'axis, and means mounting said compression spring upon said arnr with said blade extending A through said spring and. with the respective axes of Said blade and of said spring parallel to each other, said cutI-r ting edge beinglocated rearwardly of and above the.

bottom portion of said compression spring, the spacing, and tensioning of the turns of said compression spring being such as 'to permit thread to be readily drawn frictionally between successivefturns, of saidspring and against said cuttingedge for cutting of. the thread, and also being such as tonormally hold the loose cut thread frictionallyi between saidturns.

References, Cited in,thevfile,of this patent UNITED STATES PATENTS

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