US2328668A - Sewing machine - Google Patents

Description

Sept. '7, 1943.

w. E. NICHOLS SEWING MACHINE Filed July 11, 1941 2 Sheets-Sheet 1 iNyEN'h: R Luz. am, 17L GJW Q42.

Sept 7, 1943.-

Filed July 11, 1941 2 Shefcs-Sheet 2 INVEN HJ Z JMQcAQ/MM 3 171512 Qua P42.

AHysmm i MN 7 J \J r\ Q w v Q. ms Na m b \wsw. Q m AU J w v Q Patented Sept. 7, 1943 r Walter E. Nichols; lVIilton, Masa, 'a'ssig'nor to The Reece Button Hole Machine Company, Boston Masa, a corporation of Maine Application July 11, 1941;8erial No. 491,931 9 Claims. (01. 112-4242) i t This invention relates to sewing machines and especially, though not "exclusively, to button hole sewing machines of the type known as straight hole machines, described, for instance, in Patents N'os. 714,284, November 25., 1902; 749,776, January 19, 1904 1,088,652, February 24; 1914; 1,402,073, January '3, -l922,and 1,483,307, February 12, 1924.

The present invention relates particularly to thread pull-01f devices for machines of this and other types, and has for its main object the provision of novel means which not "only puil from the thread supply an amount of nee'dlethread sufficient to enable the needle to complete a stitch on its ffirst'reciprocati'on during each stitching cycle, but also assist the take-up in setting 'the last stitch in said cycle more firmly than WZIS hGIStO'fOlG d'GIl'B. 1

Before explaining in detailthe present invention it is to be understood thatth'e invention is not limited in its application to the detailsyof construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other "embodiments "and of being practiced or carried out'in various ways. Also it is to be "understood "that the phraseology or terminology employedlierein is for the pur pose "ofdescription and not of limitation, and, it

instrumentalities the sides of the buttonhole The stitch-forming comprise an eye-pointed needle 28 above the work and cooperating loopers or equivalent thread handling devices 2l' below the work, there being a throat plate 2-2 carried by thebed i5 and having anzopening through which the needle operates. The needle 2%) is carried by a needl'ebar 23 which is axially reciprocated in a needle-bar guide 2 3 by a link 25 and an arm 26 thatis firmly mounted on a shaft 27, suitably journalled'in bearings 28 (Fig.

i 2) and rocked in definite timed relation with is not intended to limi't'the invention claimed j herein beyond the requirements of the prior art.

In the drawings: l :2 1. Fig. 1 is a side elevation, "partly in section, of

a machine embodying the presel-t invention, certain parts whose particular construction and: "arrangement are not essential to the understanding "of the present invention, andwhi'ch'rn'ay be substantially as more fully shown and described in the patents a'bov'e referred 'to, being omitted for the sake of simpiicity of illustration.

Fig. 2 is a "fragmentary plan view of the machine shown partly in section, 'th'e'secti'on being taken on the line 2:2 or Fig.1.

Fig. 3 is a fragmentary side elevation of the machine similar 'to Fig. 1, showing certain ele merits in a different position, however.

The machine shown inthe drawings, which, as above stated, may, as "to its general organization, be similar to those describedin the patents above a main shaft 29 (Fig. 1) by means which are not shown. Means, not ShOWll,al8 also provided to vibrate the needle bar guide 24 transversely to the direction of feed of the work clamp in order to position the depth stitches along the sides of the button-hole. i

The main shaft 29, which is jou-rnalled in suitable bearings in the bed It, has power applied thereto by a-belt -39 alternately engageable with fast and loose pulleys 3i and '32, respectively, under the control of a belt shifter (not shown) which is carried ;by a stop motion mechanism, generally indicated at-33 in Fig. l and disclosed in detail in the above referred to patents and also in the copending application of Joseph H. Pikul, Serial No. 4:01 ;93-2, filed July 1-1, 1941. A button hole cutter to is carried bya lever dl which is'jour-nalled on a stub shaft d2 in the bed If: and has a rearward-1y extending arm 43 that V is 'drivinglyjconnected with the stop motion referred to, comprises abedlt from which rises I a standard IE, carrying an overhanging arm H. The work W is carried by aworkcl'amp or holder which comprises a clamp plate It and cooperating clamping arms -l'9,said workholder being movable as a unit over the bed, "by mechanism-not "shown, in order topcsition the stitches alone I mechanism 33 in a manner iully disclosed in said Patent No. 714,284. For a clear understanding of the present invention; it is deemed suficient to state that the stop motion mechanismofi depresses the cutter 40-, 34 into cutting engagement with the work W (Fig. 3) just before the completion of the last stitch in-a sewing cycle of the machine, and quickly returnsv saidcutter toits normal inoperative position (Fig. l) on completion of said last stitch, i. -e., when thestop motion mechanism has shifted the 'belt 30 from the fast pulley 31 to the loose pulley 32 and is about tostopthe momentum of the moving machine parts by a recoil action which is fully described i-n said copending application.

The construction of the machine so far delever 26 (see Fig, 2) which serves also as the take-up arm of the machine, and finally through an auxiliary, spring controlled tension device 55 on the needle bar guide 24. The pulloff lever 52 is pivoted at 56 to the overhanging machine arm I! (see also Fig. 2), and drivingly connected with the cutter-carrying lever 4| through intermediation of an arm 51 and a link 58. The arm 57 is rotatably mounted on the pivot 56 and relatively angularly adjustable with respect to the pull-off lever 52 by means of the slot and screw connection 60, 53. The link 58 is also adjustable to and from the rotary axis of the arm 5'! by means of the screw and slot connection 62, 63 (see also Fig. 2). During a stitching cycle of .the machine, the take-up arm;

25. oscillates in synchronism with the needle reciprocations and sets each stitch on eachascent of the needle, while the pull-off arm 52! being drivingly connected with the cutter-carrying lever 4|, remains in the normal inoperative position shown in Fig. 1 until the formation of the last stitch in the sewing cycle. I'he cutter 40 is so operatedby the stop motion mechanism 33 that the same descendsinto cutting engagement with the Work W during the setting of the last stitch in a sewing cycle, 1. e., during the last ascent of the take-up arm 2% in said sewing cycle, with the result that the pull-off lever 52 is simultaneously moved-from the position shown in Fig. 1 into the lowermost position shown in Fig. 3. Such simultaneous and onposed movement of the take up arm 26 and pulloff lever 52 results in their cooperation in setting the last stitch in a sewing cycle and'in drawing extra needle thread or starting thread from the supply, as will be readily understood. The pulloff lever 52 is thereupon quickly returned to its normal inoperative position (Fig. 1) at the time, or very shortly after, the take-up arm 26 reaches its uppermost position, leaving between the tension devices and a length of thread t which is sufficiently slack to require, during the formation of the first stitch in the next sewing cycle and for reasons which'will become apparent hereinafter, more than a full take-up action by the arm 26 in order to become taut. Any'conventional thread-trimming "device (not shown) maybe provided underneath the throat plate 22 in order to sever the last needle thread loop (Fig, 1) held by the thread-handlingdevice 2!, whereby that leg of the loop :is preferably severedwhich leads to the stitches in the work W in order to leave a maximum length of thread depending from the eye of the needle'2ll. I

The above referred to copending application Serial No. 401,932 discloses a thread'trimming device which may be used advantageously here. This thread trimming device is operated when the mentioned recoil action of the stop motion mechanism takes place, and severs that leg of the loop which. leads to the stitches in the work W. If this last mentioned threadtrimming device is used, which becomes I operative after the return of the cutter 40 and the thread pull-off lever 52 into their normal inoperative position shown in Fig. 1, the auxiliary tension device 55 exerts sufficient'force on'the thread i to enable the thread trimming device to perform its intended operation withoutdrawing from the slack thread between the tension'devices 55 and 50, m

On the first down or work: stroke of the needle 20 in the next stitching cycle, the needle draws in a length of the severed thread end depending therefrom until it penterates the work W. Once the needle has penetrated the work W, the thread is so abruptly bent through the needle eye and encounters so much friction on the needle and in the cloth that the thread will travel with the needle throughout the remaining work stroke thereof, thereby drawing some of the slack thread between the tension devices 55,59] through the auxiliary tension device 55. When a looper 2i enters and enlarges the needle thread loop, the same will draw further slack thread through the auxiliary tension device, rather than draw the severed end of the thread through the work and spoil the first stitch. During the following ascent of the needle, the takeup arm 26 merely takes up the rest of the slack thread between the tension devices 55 and '50, thus preventing said take-up arm from pulling the first stitch from the work W. Substantially after the setting of each following stitch in the sewing cycle, 1. e., shortly before the ltake-up arm 26 reaches its uppermost position during each of the following ascents of the needle, the take-up arm draws sufficient thread for the next stitch from the supply, To adjust the take-up action of the arm 26 to various weights or. thicknesses of work materials, the pull-off arm 52 is angularly adjusted relative to the arm 5i bymeans of the screw and slotconnection El and 6!), as will be readily understood by those skilled in the art. In order to adjust the machine for more or less starting thread, the pivot connection between the link 58 and the arm 5'! is adjusted to andfrom the rotary axis of the latter by means of the screw and slot connection 62, 63. When this last adjustment, is properly undertaken, the leading or severed end of the thread is consumed without showing'on the top side of the buttonholc,. and any trace thereof is completely .covered- .by the barring stitches ther'eat. I

I Inasmuch as the take-up arm 26 and the pullofi lever 52 move in opposite directions when cooperating to set the last stitch in a sewing cycle and to draw starting thread for the next sewing. cycle from the thread supply, it stands toreason that the slack needle thread is taken up, and saidllast stitch set considerably before thetake-up"armireaches the end of its stitch- .settingmov'ement, with the resultthat the last stitch in a sewing cycle is set without. fail and very firmly, The firmness of, the stitch setting is, as usual, regulated by; adjusting the conventional tension device fiflinja well known manner.

1.; In a sewing machine, stitch-forming mechanism including a needle and a;take-up arm movable during each stitch-forming cycle to take up the needle thread, a device for operating said mechanism in a predetermined sewing cycle, comprising a plurality ofstitch-forming cycles, to form a stitch group, a movable needle thread pull-off member, andmeans operated in timed relation with said device to move said member during the thread take up movement of said arm in the last stitch-forming cycle of a sewing cycle such-that said arm and member cooperate inv drawing from the supply sufiicient needle thread for the initial stitch in the next sewing cycle of said mechanism.

2. In a sewing machine, stitch-forming mechanism including a needle and a take-up arm movable'during each stitch-forming cycleto take up the needle thread, a device for operating said mechanism in a, predetermined sewing 2,328,668 cycle, comprising a plurality of stitch-forming 3. In a sewing machine, stitch forming mech- I anism including a needle and a take-up arm movable during each stitch-forming cycle to take up the needle thread, a device for operating said mechanism in a predetermined sewing cycle, comprising a plurality of stitch-forming cycles, to form a stitch group, a movable needle thread pull-off member between which and said take-up arm the needle thread extends freely, and means operated in timed relation with said device for moving said pull-off member during the movement of said take-up arm in the last stitch-forming cycle of a sewing cycle in opposition to said take-up arm so that said pull-on member and take-u arm cooperate to set the last stitch in said sewing cycle and to draw from the supply sufficient needle thread for the ini tial stitch in the next sewing cycle oisaid mechanism.

4. In a buttonhole sewing machine, stitchforming mechanism including a needle and a needle thread tension and a take-up arm between said needle and tension, stopping meansfor said mechanism, a buttonhole cutter, means operated during the setting by said take-up arm of the last stitch in a sewing cycle of said mechanism for actuating said cutter, and a movable starting thread pull-01f member between said needle and tension operated by said cutter when the latter is actuated.

5, In a buttonhole sewing machine, stitchforming mechanism including a needle and a needle thread tension and an upwardly and downwardly movable take-up arm between said needle and tension, stopping means for said mechanism, a buttonhole cutter, means operated during the setting by said take-up arm of the last stitch in a sewing cycle of :said mechanism for actuating said cutter, and an upwardly and downwardly movable member between said takeup arm and tension moved by the cutter, on actuation of the same, in opposition to said take-up arm to draw extra starting thread from the needle thread supply.

6. In a buttonhole sewing machine, the combination of stitch-forming mechanism including a needle and a needle thread tension and a takeup arm between said needle and tension, stopping means for said mechanism, a buttonhole cutter, means operated during the setting by said take-up arm of the last stitch in a sewing cycle of said mechanism for moving said cutter into operative position, a pivoted starting thread pulloff lever between said needle and tension, and a link between said cutter and pull-off lever to cause operation of the latter when the former is moved into its operative position.

7. The combination in a buttonhole sewing machine as set forth in claim 6, in which said link is adjustable to and from the pivot axis of said pull-off lever.

8. In a buttonhole sewing machine, the combination of stitch-forming mechanism including a needle and a, needle thread tension and a takeup arm between said needle and tension, stopping means for said mechanism, a buttonhole cutter, means operated during the setting by said take-up arm of the last stitch in a sewing cycle of said mechanism for moving said cutter into operative position, a pivoted starting thread pulloii lever between said needle and tension, another arm pivoted coaxially of said pull-01f lever and relatively angularly adjustably secured to the latter, and a link between said other arm andcutter to cause operation of said pull-off lever when said cutter is moved into its operative position. I

9. The combination in a buttonhole sewing machine as set forth in claim 8, in which said link is adjustable to and from the pivot axis of said other arm;

WALTER E. NICHOLS.

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