US713584A - Thread-controlling device for sewing-machines. - Google Patents

Description

No. 78,584. Patented Nov. I8, I902. E. B. ALLEN.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

(Application filed Mar. 31, 1902.)

(No Model.) 2 Sheets-Sheet l.

WTNE/EEI I j N0. 7l3,584. Paient ed Nov. I8, 1902.

E. B. ALLEN.

THREAD CONTROLLING DEVICE FOR SEWING MAGHlNES.

(Application filed Mar. 31, 1902.) v (No IdQel.) 2 Sheets-Shet 2.

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ilwrrno STATES PATENT OFFICE.

EDW'ARD B. ALLEN, OF ELIZABETH, NEl/V JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF N EW' JERSEY.

THREAD-CONTROLUNG DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 713,584, dated November 18, 1902.

Application filed March 31, 1902. Serial No. 100,760. (No model.)

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Thread-Controlling Devices for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

In many buttonhole-stitching machines now in use the stitclrforming mechanisms so operate that a loop of needle-thread (usually the thread of the depth-stitch needle) is engaged by a looper beneath the work-plate at the time when the machine is stopped at the completion of a buttonhole, so that when the work is shifted for the purpose of stitching the next buttonhole a doubled length or section of needle-thread will extend from one buttonhole to another on the lower side of the work in addition to a single length orsection of looper-thread, and when the needle thread or threads running between the buttonholes on the upper side of the work are trimmed off loose ends or whiskers are liable to or do appear on the under side of the work. Even if the depth-stitch thread be cut by an automatic or other thread-cutter, which severs the needle thread or threads close to the upper side of the work before the latter is shifted for a new button-hole, the thread comprised in the loop around the looper and equaling in length the distance from the work above the throat-plate down to and around the looper and back to the work will still remain as a loose end or whisker at each buttonhole, which is objectionable.

This invention has for its object to avoid the objection referred to by providing means for preventing the needle-thread from forming a loop to be engaged or entered by the looper at the time when the last half-formed stitch of a buttonhole would otherwise be made, so that there will be no loop of needlethread beneath the work or beneath the throat-plate when the machine is stopped and the work is shifted for the next buttonhole, and thus no needle-thread will extend between the buttonholes on the lower or inner side of the work. This object is effected by providing an automatic mechanism which will place such extra stress on the needlethread as will take up all the slack thread between the tension device and the eye of the needle after the last complete stitch of a buttonhole hasbeen formedin suchamannerthat no loop can be thrown out by the needle to be entered by the looper at the moment the machine is to be stopped previously to shifting the work for the next buttonhole, and thus at the time the work is shifted there will be no loose needle-thread below the work and no needle-thread will extend between the buttonholes on the lower side of the completed work. In other words, the invention provides an automatic loop-robbing device for a particularly-timed stitch or needle descent in the cycle of operations necessary for Working a buttonhole or group of stitches on an automatic machine, the automatic loop-robbing device being preferably of such construction as to serve also as a thread-slackening device to draw sufiicient needle-thread through the tension device to reach from one buttonhole to the next above the work when the work is shifted.

In the accompanying drawings, Figure 1 is a side View of a buttonhole-stitching machine embodying the present invention. Fig. 2 is a detail plan view illustrative of the loop-robbing device, and Fig. 3 a detail side view of the same. Fig. 4 is a detail view looking from the right of Fig. 3, and Fig. 5 is a detail sectional side view illustrating looping devices in connection with which the present invention may be employed.

Referring to the drawings, Adenotes a base, rigid with which is a work-support A, said base being provided with a standard A with which a movable stitch-frame B has preferably a double pivotal connection, as in the machine fully shown and described in my United States application, Serial No. 24,679, filed JulyQe, 1900. It will be understood, of course, that the present invention is not confined to any particular construction of automatic buttonhole or other sewing machine and that its present illustration is merely intended to show one form of machine in connection with which it may be employed. The stitch-forming devices of the machine herein shown comprise out-of-time depth-stitch and slit or edge needles d d and thread-carrying and nonthread-carryingloopersf andf all mounted for periodical rotary movements about the eyes of the buttonholes, as in the machine shown in my application above referred to; but it will of course be understood that in utilizing the present invention in connection with a machine for working eyed buttonholes either the work or the stitch-forming devices may be periodically rotated to stitch the eyes of the buttonholes, and it will also be understood that the invention is equally applicable to machines for working straight buttonholes, eyelets, barring or staying or sewing on buttons, or othermachines for formingseparated groups of stitches of any kind and employing stitch-forming mechanisms comprising loopers and forming chain-stitch (in contradistinction to lock-stitch) seams.

The present machine is shown as being provided with tension devices 0 and O and takeup devices or arms D and D for the threads of the two upper needles employed; butif the present invention were to be applied on a machine having a lower slit needle the threadcontrolling devices for said lower needle would preferably be differently located than at the top of the arm of stitch-frame, as here in shown. Placed conveniently adjacent to the tension device 0 and take-up device D for the depth-stitch needle d is a lever E, having its fulcrum on the screw or stud e and preferably having a slotted lower arm engaged by a pin or lugf at the upper end ofalever F, controlled by a springf, which normally holds said lever F in the position shown in full lines in Fig. l.

P denotes the clutch-controlling or stopmotion lever of the machine embraced by my application hereinbefore referred to, and to which lever is attached the rear end of a rod 0", havinga lug or projection r to be engaged by a tripping lug or projection Q12 on the rotating cam-wheel g, which controls the rotating movements of the stitch-forming devices, the engagement of the said tripping lug or projection Q12 with the said lug or projection 9' serving to operate the clutch-controlling stop-motion leverP, so as to stop the machine at the completion of a buttonhole, and as the said lug or projection 'r is so arranged that its upper part will engage the lower end of the lever F said lever will be operated to actuate the leverE at the instant just before the machine is stopped.

The upper arm of the lever E is provided with a thread-controller, preferably in the form of a spring-wire looped arm e, arranged to act on the thread between the tension device O and the needle and also preferably between the take-up arm or device D and the needle, although this last-mentioned pointis notessential. Thespring thread-controlling arm e extends upward through a loop 6 on the upper arm of the lever E and which loop 8 serves to limit the movements of the springarm e relative to the lever E in both directions.

The operation of the loop-robbing device is as follows: When the rod 1', controlling the stop-motion lever P, is shifted to the right, Fig. 1, to stop the machine at the completion of a buttonhole, the levers F and E are moved from the positions shown in full lines to the positions denoted by dotted lines in Figs. 1 and 3, causing the spring thread-controlling arm 6, connected with said lever E, to so act on the thread running to the depth-stitch needle cl as to take up all the slack of said thread and to put the said thread under such tension as will. prevent said needle at this time from throwing out a loop to be entered by the non-thread-carryinglooper f so that said needle-thread will not at what would be the stitch next after the last stitch of a completed buttonhole be detained beneath the throat-plate of the machine. From this it results that when the work is shifted from a position for forming one buttonhole or one group of stitches to another there Will be no needle-thread on the lower side of the work between the separated groups of stitches, thereby not only obviating the present existing objection to the presence of the useless and unsightly surplus thread where it is not wanted, but resulting in a considerable saving of the relatively costly silk needle-thread usually employed in stitching buttonholes.

The lever E, when operated, as above described, to take up all the slack thread between the tension device and the needle, is preferably given a movement of sufficient range or extent not only to take up all the slack referred to, but also to draw through the tension device sufficient slack thread to extend from one buttonhole or separated group of stitches to another on the upper side of the work, and thus obviates the necessity for drawing or pulling out this requisite slack thread manually or for providing a special slack-thread-drawing device for this purpose, it being understood that the tension will be automatically released, as is usual, prior to the time when the extra slack referred to is drawn through the tension device. In performing its double functions referred to the lever E is at one time given sufficient movement to effect the results stated; but after having taken up all the slack thread the spring-arm e engaging the threads yields, owing to its pressure on the thread, and is under sufficient stress or tension, so that as soon as the tension of this tension device is released the stress of the spring-arm e acts to draw through the said device the slack thread necessary to extend to the next buttonhole or group of stitches by utilizing the stored-up power due to the stress or tension under which the said spring-arm is placed.

This invention is not to be understood as being limited to the particular mechanism or l 4' H. I

the special means herein shown and described for preventing the looper from engaging or entering a loop of needle-thread at the needle descent or stroke occurring just next or after the completion of a group of a predetermined number of stitches, as this result may be accomplished in other ways than that hereinbefore described, as by automatically throwing either the needle or the looper slightly out of time with its normally cooperating complementary stitch-forming element at the particular stroke of the needle referred to or by automatically moving the looper sidewise slightly at the needle-stroke referred to, so as to cause said looper to avoid the needle-loop formed at that time.

Having thus described my invention, I claim and desire to secure by Letters Patent 1. In a sewing-machine for forming sepa rated groups of stitches, the combination with a stitch-forming mechanism comprising a needle and a cooperating looper, of automatic means for preventing the needle-thread from being detained beneath the throat-plate at the needle-stroke occurring next after the completion of a group of stitches.

2. In a sewing-machine for forming separated groups of stitches, the combination with a stitch-forming mechanism comprising a needle and a cooperatinglooper, of an automatic loop-robbing device for preventing the needle-thread from being detained beneath the throat-plate by the looper at the end of the completion of a group of stitches.

3. In a sewing-machine for forming separated groups each comprisinga predetermined number of stitches, the combination with a needle and a cooperating looper, of a stopmotion mechanism for controlling the number of stitches for each group of stitches, and an automatic loop-robbing device operated from and controlled by said stop-motion mechanism.

4. In a sewing-machine for forming separated groups of stitches, the combination with a stitch-forming mechanism comprising a needle and a cooperating looper, of a slack-controlling and thread-drawing lever having a spring-arm or yielding resilient portion, and automatic means for causing said lever to take up the slack needle-thread at the end of the completion of a group of predetermined number of stitches, said lever having a range of movement greater than is necessary to control the slack thread to be taken up so that said springarm or yielding resilient portion of said thread-controllin g lever will be placed under tension, thereby storing up power in said arm or resilient portion to be utilized, without further movement of said arm, to draw slack thread from the tension device, when the normal tension on the thread is released.

5. In a sewing-machine for forming separated groups of stitches, the combination with a stitch-forming mechanism comprising a needie and a cooperating looper, of the needlethread-controlling lever E provided with the spring-arm e, the stop-motion or clutch-controlling lever P and connections between said levers E and P whereby the former will be operated by the latter when the machine is stopped.

6. In a sewing-machine for forming separated groups of stitches, the combination with astitch-forming mechanism comprising a needle and a cooperating looper, of the needlethread-controlling lever E provided with the spring-arm e, the stop-motion or clutch-controlling lever P, the rod or bar 1" provided with a lug or projection, and the lever F operatively connected with the said lever E and arranged to be engaged by the said lug or projection of the rod or bar 0" to operate said lever E to cause it to take up the slack of the needle-thread when the machine is stopped.

In testimony whereof I affix my signature in presence of two witnesses.

EDWARD B. ALLEN.

Witnesses:

HENRY J. MILLER, HENRY A. KORNEMANN.

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