Thread-cutting device for sewing-machines.

Abstract

Claims

No. 612L149. PatentedAu'g. 20, 101.. .1; J. I SULLIVAN. THREAD CUTTING DEVICE FOR SEWING MACHINES. (Application filed July 28, 1898.) (No Model.) 2 Sheets-Sheet I. v THE norms PETERS co. momumu wAsumurou,o, c. FFICE. JOHN J. SULLIVAN, OF IPSVICH, MASSACHUSETTS. THREAD-CUTTING DEVlCE FOR SEWING-MACHINES. s rucrnrca'rrolv forming part of Letters Patent No. 681,149, dated August 20, 1901. Application filed July 28, 1898. To 01. whom it may concern; Be it known that 1, JOHN J. SULL1vAN,a citizen of theUnited States, residing at Ipswich, in the county of Essex and State of Massachusetts, have invented certain new and useful f Improvements in Thread-Cutting Devicesfor v Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings. no t This invention has for its object to provide a thread-cutting mechanism applicable to machines for sewing on buttons, stitching buttonholes, barring buttonholes; forming I,bars or stays, and the like and by means of which the threador threads running between 1 buttonholes or groups of stitches may be severed. in two places,so as to cut out pieces of thread,and thus remove the surplus thread from thework. To this end I'provide two shear thread cutters or thread-cutting de- ,vices which are separated from each other a e distance equal to the length or piece of thread j tobe cut out, said thread-cutters being preferably automaticallyoperated at the proper y intervals orafter each buttonhole, bar, or stay LOT. other group of stitches has been formed, Sthus severing the thread or threads close up to the bar or other group of stitches just formed and also close up to the bar or other ,group of stitches about to be' formed, so as RIO cut olt thethread or threads close to both i sides of each bar or group of stitches. In the accompanying drawings, Figure l is ea rear sideelevation of a button-sewing ma- .chine embodying the invention. Fig. 2 is a partial frontend View of the same on a larger scale than. Fig. 1. Fig. 3. is a partial rear 1 side view on the same scale as Fig. 2 to show the, cutting device, and Fig. 4 is a front side 4e view of the cutting device. Fig. 5 is a detail 1 sectional viewon the line 5 5,Fig. 4. . 1. The machine to which I have shownmy presentinvention as being applied is in its general construction and. operation substantially the same as the button -sewing man: y chine fully shown and described in my Patent No. 596,020, dated December 21, 1897, and comprises'rnechanism for making a group y .Xof a predetermined number of ovcrseaming- .15 stitches in one place for the purpose of at- Serial No. 687,076. (No model.) taching the shank or eye of a button to a shoe or other article, and after the desired number of stitches has beenformed the machine is automatically stopped. The automatic work-feed described in my said patent is omitted from the present machine, and in the operation of the present machine the attendant shifts the work from one buttonsewing position to the next, the presser-foot being raised by the treadle-operated lever 0 when the work is to be shifted. As the machine forrns lock-stitches comprising an upper or. needle thread carried by a needle d and a shuttle or lower thread carried by a shuttle e, these threads would, if not severed, extend loosely from group to group of button-attaching stitches on both sides of the work. The loose shuttle-thread being on the back or wrong side of the work, and thus ordinarily concealed, is not seriously objectionable; but the loose needle-thread on the face or right side of the Work presents an unsightly appearance and has heretofore been trimmed off by hand with scissors. This hand-trimming of the needle-thread is done away with by the present invention, which provides means for automatically cutting out the surplus loose needle-thread between the groups of button-attaching stitches. In the form of my invention herein illustrated two thread-cutting knives or blades a ct are attached to a cutter-lever a., pivotally attached by a pin 17 to the stock portion 79 of the presser-foot, comprising two parts b and b ,between which and beneath the stock 5 is formed a thread-receiving slit or threadguide 6 Any suitable stationary parts, as 1) b on the presser foot and its shank to cooperate as ledger-blades or otherwise with the blades a a may be provided. The movcam-groove e of the intermittingly-rotating 100 cam-cylinder E, as in the machine shown by my said PatentNo. 596,020. As the movement of the lower end of the extended lever m is somewhat greater than is necessary to produce the required movement of the cutterlever a, the bar or link 0 is provided with a slot 0, in which the pin or screw 0 connecting said lever and bar or link, can have a limited play, so that thebutton-feeder on will have performed part of its movement before the cutter-lever is operated to cut out the thread by the two separated blades or cutters a a, which are spaced or separated from each other a distance equal to the length of the piece of thread to be cut out. The side walls of the thread-receiving slit or thread-guide b in the bottom of the presserfoot serve as positive guiding means for directing the thread into position to be cut by the knives or blades a a, which when they are operated to cut the thread are moved across or transversely to said slit. The right-hand wall of the thread-guiding slit or slot 11 is notched to afford a small shoulder or projection If, on which the thread will catch and which will therefore serve to hold the thread in cutting position, as will be hereinafter indicated. To vary the length of the piece of thread to be cut out by the separated threadcntters, interchangeable cutting devices with differently-spaced cutters maybe employed. This same result might be secured by mounting the cutters in such a way that they may be adjusted from or toward each other by a screw or other adjustment. When a group of a predetermined number of button-attaching stitches has been formed, the machine is automatically stopped with the needle in its raised position, and the presser-foot is then lifted slightly to release the work. The attendant now shifts the work laterally or toward the left, referring to Fig. 2, to bring the work into position for sewing on the next button. In forming the buttonattaching stitches the needle occupies a position between the prongs b b of the presserfoot (see Fig. 5) and in line, or approximately so, with the thread-guiding slit or slot b and thus as the work is shifted by the attendant the thread running from the work to the eye of the raised needle draws naturally into the said thread-guiding slit or slot and is positively directed by the walls thereof to cutting position within the range or path of movement of the blades a a. Before the machine is again started for the formation of the next group of button-attaching stitches the presserfoot is lowered on the work, and to prevent the thread from getting out of range of the left-hand blade a, Fig. 2, the attendant holds the work lifted slightly at the rear or lefthand end of the presser-foot. When the needle first descends in commencing the formation of the next group of button-attaching stitches, the needle-thread is caught on the shoulder 19 at one side of the thread-guiding slit or slot 12 and is prevented by said shoulder from being drawn down out of'the said slit or slot, and thus out of range of the righthand blade a, referring to Fig. 2. After the thread has been fastened in the work by the formation of two or three stitches and before the group of stitches is completed the blades or cutters a a are operated by the mechanism hereinbefore described, so as to cut out a piece of thread equal in length to the distance between the said blades or cutters a a. 4 While I have illustrated my double threadcutter adapted to out out a piece of thread in connection with a button-sewing machine, it will be understood that it is equally applicable to buttonhole-stitching or to barring or staying machines or to other machines forming groups of stitches with loose threads between them, and I do not therefore wish to be understood as limiting my invention to any particular form of sewing machine. Also instead of operating this double threadcutter automatically it might be actuated manually by the attendant, or it might be arranged to sever the shuttle or looper thread without departing from the spirit of my invention. Having thus described my invention, I claim and desire to secure by Letters Patcut-- 1. In a sewing-machine, the combination with a presser-foot provided with a threadreceiving slit, as 12 of two separated or spaced shear thread-cutters mounted on said foot and each adapted to make a separate out through a thread extending in said slit from one cutter to the other, so as to out out a piece of thread, and means for actuating said thread-cutters. 2. In a sewing-machine, the combination with a presser-foot provided with a threadreceiving slit, as 11 of two separated or spaced shear thread-cutters, a cutter-lever pivotally attached to said foot and by which said blades or thread-cutters are carried, and means for operating said lever. 3. The combination with a sewing-machine presser-foot having the cutting parts I), b and a thread-slit 12 of the cutter-lever a. pivotally attached to said foot, the separated blades or cu'tters'ct, a, carried by said lever, the bar or link 0, the lever m and a cam for operatin g said lever m at. In a sewing-machine, the combination with the stitch-forming mechanism thereof, of two separated or spaced thread-cutting devices adapted to cut out a length or piece of thread, said thread-cutting devices each comprising a cutting-blade and an opposing cutting device, positive guiding means for directing the needle-thread to said cutting devices, and means for operating said blades. Q In'a, sewing-machine, the combination with thestitch-fel ming mechanism thereof; oftwoseparated o r spaced thread-cutting dethread, said thread-cuttin g deviceseach comprisinge cntting b1adeend an opposing entvices adapted to? cut out a length or piecelof ting"deyicegpesitive guiding means for dimeetingtheneedle-thread to said eutting devices, and automatic means for operating said blades. e In testimony whereof I affix my signature in the presence of two Witnesses. " JOHN J. SULLIVAN. Witnesses: 1 j HENRY J. MILLER, v HAROLD W. BROWN.

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    Publication numberPublication dateAssigneeTitle
    US-3149595-ASeptember 22, 1964Rand Mcnally & CoThread chain severing means for book sewing machines