US1646946A - Cord-handling mechanism for buttonhole-sewing machines - Google Patents

Description

Oct. 25 1927.-

E.'B. ALLEN CORD HANDLING MECZ IANISM FOR BUTTONHOLE SEWING MACHINES Filed Jan. 23. 1926 5"Sheets-She'et' 1 INVENTOR 6 @WM ATTORNEY WITNES ES en! Oct. 25 1927.

E. B. ALLEN CORD HANDLING MECHANISM FOR BUTTONHOLE SEWING MACHINES 5 Sheets-sheaf 2 Filed Jan. 23. 1926 f INVENTOR TTORNEY E. B. ALLEN CORP HANDLING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed Jan. 25. 1926 I 5 Sheets-Sheet' 3 INENTOR WITN$SFS I Oct. 25 1927. 1,646,946

E. B. ALLEN CORD HANDLING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed Jan. 23- 1926 S'SheetS' -Sheet' 4 INVENTOR WITNESSES BY fiRNEY oct. 25, 1921. 6

E. B. ALLEN CORD HANDLING MECHANISM FOR BUTTONHOLE SEWING MACHINES Filed Jan. 23. 1926 S'SheetS' Sheet 5 f INgTOR wmuzs s I Y BY i j zTTonm r W aw I Patented Oct. 25, 1927.

UNETED STATES EDWARD 1B. ALLEN, OF NEWTORVN, CONNECTICUT, ASSIGNGR TO THE SING-ER BIANU- FAGTURING COMEANY, 01* ELIZABETH, NE'W JERSEY, A CORPORATION OF NEW JERSEY.

CORD-HANDLING MECHANISM BUTTONHOLE-SEXVIHG MACHINES.

Application filed January 23, 1926. Serial No. 83.210.

This invention relates to sewing machines of the buttonhole type adapted to sew a group of stitches and then come to rest. Machines of this type commonly embody ovcrseaming stitch-forming mechanism and :1V work-holder with means for relatively moving them to sew about a buttonhole. A cord-guide is customarily provided adjacent the sewing point to deliver a stay-cord or gimp thread within the range of action of the stitch-forming mechanism so that such cord will be embraced within the over-seam; the cord-guide being commonly formed as a small hole in the usual needlc-throat member. Means are also commonly provided for cutting the cord, as well as the sewing threads, after the sewing operation has been completed.

To avoid retrimming operations it is desirable, with machines of the class described. that the cord and sewing threads be cut close to the last stitch in the work and a free end of cord is thus left protruding from the needle-throat member; the length of this free end of cord being usually such that when the next sewing operation is started, such end projects obj ectionably from the beginning point of the overseam and requires to be retrimmed. This requirement is troublesome and entails a wastage of cord. T1 the retrimming is done automatically, the accumulation of retrimmed cord ends tends to clog the stitch-forming mechanism and otherwise interfere with. the proper operation of the machine.

The present invention has for an object to avoid cord wastage and the diliicult-ics incident to retrimming the cord. To this end means are provided for pulling the cord back through the cord-guide so that the protruding end of the cord will be no longer than required to be safely bound by the initial stitches.

The cord pull-back mechanism may comprise a cord-engaging implement with means for giving it a single to-and-fro movement at the proper time across the lead of the cord between the cord-guide and a suitable cord nipper; the latter device being actuated to arrest the feed of the cord while the cord is engaged by the pull-back implement.

After the pull-back implement has acted, the cord is left in a slack condition so that it will run free of tension until the cord end is safely bound by the initial stitches.

In the accompanying drawings, Fig. 1 is a side elevation of a buttonhole sewing machine embodying the invention. Fig. 9. is a horizontal section through the bracliet-arm standard SllOWlIlg the machine bed in plan. Fig. 3 is a partial front end elevation of the machine. Figs. 4 and 5 are, respectively, plan and elevation views of the parts adjacent the sewing point at the end of the sewing period after the work has been shifted to buttonhole cutting position. Figs. 6 and 7 are respectively plan and elevation views of the same parts at a slightly later stage when the turret carrying the lower stitch-forming instrumentalities and cordguiding means has been reversely rotated 180 to restore itto initial position; the cord-cutter being active at the close of this reverse rotation. Figs. 8 and 9 are respectively plan and elevation views of the same parts at a still later stage when the stitched buttonhole is being actedupon by the buttonhole cutting mechanism. In Figs. 8 and 9 the cord pull-back and nipping elements are shown in operative engagement with the cord.

For the purposes of the present disclosure the invention is described as embodied in an automatic eyelet-end buttonhole sewing machine, the frame of which comprises the hollow rectangular bed 1 from one end of which rises the standard 2 of the overhanging braclzct-arm 3 terminating in the head 4.

The stitclrforming' mechanism is constructed substantially in accordance with the disclosure of the Allen et al. Patent No. 1,372,473, of Mar-ch22, 1921, and comprises the usual upper and under thread. mechanisms. The upper thread mechanism comprises the reciprocating and laterally jogging needle 5 carried by the needle-bar 6 which is reciprocated by means of the link connection 7 with the crank 8 on the upper shaft 9. The shaft 9 is geared to the vertical shaft 10 which is driven by the lower main sewing shaft 11. The under thread mechanism comprises the usual loop-taking devices 12 which, together with the usual needlethroat member 12 are carried by the rotary turret 1 3.

The loop-taking devices are actuated through,

suitable connections with the shaft 11. The

turret 13' and needle-bar 6 are at times rotated in unison, as in sewing around the eyelet-end of a buttonhole, by means of the respective sector gears 14, 15, connected by links 16, 17, to cranks 18, 19, on the vertical shaft 20. The crank 18"Fig. 2 has a follower 21 entering the stitch-forming mechanism rotating groove 22 in the feed-wheel 28. During the sewing, the feed-wheel 23 driven at a relatively slow speed, through suitable gear connections, not shown, by the sewing shaft 11. At other times the feed-wheel is driven at a higher speed by the rapid feedshaft 24 which carries a gear 25 meshing with gear teethaon the. feed-wheel and re ceivcs its motion through a clutch-connection, not shown, from the constantly rotating lower shaft 26. The period of action of the sewing shaft 11 is controlled by the usual stop-motion device 27 through which such shaft isconnected to and disconnected from the constantly running belt-pulley 28.

The work-holderis constructed substantially in accordance with the disclosure of the Allen Patent No. 15,324, reissued April 4, 1922, and comprises the lower clampplates 29 and upper clamping feet 29 carried by the crossjslide-plate 30 mounted in turn on the longitudinal slide-frame 31 adapted to slide in suitable ways in the mas chine bed. The cross'slideplate 30 and longitudinal slide-frame 31 are actuated by the usual connections with the feed-wheel as described in said reissued patent. hen the machine is started the work-clamp occupies a position removed from sewing position. It is first shifted rapidly by the rapid feed-drive to sewing position, then is given h a slower step-by-step motionas the sewing proceeds around the buttonhoie and finally is given a rapid shift baclrto initial position, in w'iich position the buttonhole and cord, as well asthe under thread, are out.

The buttonhole cutting mechanism is constructed substantiallyin accordance with the disclosure of said reissued patent and com prisesfthe upper and under cutter- levers 32, 33, fulcrumed at 34 on the fulcrum-block 35, Fig. 2, to which travelling movements longitudinally of the bed 1 are given by means of the link-connections 36' from the cutter-advancing and '-retracting cam .37 on the cutter-shaft 38. .The cutter-levers are closed to cut the buttonhole by means of the cutter-closing cams-39, 10, on the cuttershaft 38 which is actuated from the constantly running pulley 38 through the usual automatic one-revolution clutch-device 38*.

The under threadand cord-cutter is constructed substantially in accordance with the" disclosure of my Patent No. 1,579,200, dated Aprg6, 1926. It comprises a scissors device including ablade .41 fixed to a carrier-lever 42fulc rumed at l3 on the machine frame. A second'blade 414 is'fulcrumed at 45 on the first mentioned blade 41' and has a tail-piece which carries a follower 46 entering a stationary cam-groove 17. When the lever 42 is swung about its pivot 43 the scissor-blades are projected in open relation transversely across'the lead of the under thread and cord between the last stitch and the needle-throat member; the blade 11 grazing the under surdevice, the inclined end-portion 47' of the cam-groove 4-7 swings the blade 44 to cut the threads and cord close to the work,*asshown in Figs. 6 and In the particular machine illustrated the actuating mechanism for the scissors carrying lever is constructed substantially in accordance with the disclosure of my copending application Serial No. 6 l:9,-i l0,-filed July 5, 1923, and comprises an actuating lever 18 fu'lcrumed at 49 on the frame-bracket 50 and connected at. its front end by a link 51 to the scissors-carrying lever 42. The lever 48 has a follower 52 en-- tering the cam-grooves 53 in the gear-member 25 on the rapidfeed shaft 24. The camgroove 58 has an eccentric portion 53 which is tuned. to quickly advance and close the threadand cord-cutting device after the work has been shifted from sewing to buttonhole cutting position and before the buttonhole cutting mechanism is tripped into action; r I V r The cord 0 is led to the needle-throat member through a stationary cord-tube 5 1 me thence across the under flat nipping face 55 and up through a guiding aperture 56 in a cord-nipper jaw member 57 thence to and through the usual cord delivery aperture in the needle-throat member 12*. A light tension'spring 58 on the upper face of the jaw member 57 puts a light drag on the cord 0. The nipper-jaw member 57 is mounted on the rotary turret 13 and at times is coopei indellendsntly Of the turret.13;

atively related to the nipper-jaw member 59 fulcrumed at (30 on the machine frame. The nipper-jaw member 59 is formed as a lever having a tail piece (31 which is acted upon by a roll (32carried by the cord pulls back bar 63 mounted on the travellin fulcrum block 35 which carries the butto inhole cutter- levers 32, 33. Thetail-piece 61 of the cord-nipper lever 09 is formed with a camrise 64 which is engaged by the roll 62 during the advance of the cutter-levers preparatory to' the cutting of'thebuttonhole. Such engagement causes the flipper-jaw 59 to pinch the cord 0 against the under face of, the jaw .57 and thus to arrest the feed of the cord. The cord pull-back 63 isformed at its forward end with a finger 65 and shoulder 66. During the advance of the button-hole critterlev1-s, the 'iinger xi5passes under the cord between the cord-guide 56 and the needle-throat member; the shoulder 6 engaging the cord and pulling a measured length of cord back through the core delivery aperture in the needle-throat member.

The cycle of operations is as follows: After the sewing operation has been completed and the action of the rapid feedshaft has carried the work from sewing to buttonhole cutting position, the parts are in the position shown in Fig. 4; the nipperjaw member 57 being spaced 180 from its companion jaw 59. The final movement of the 1 )id feed-shaft 2-1: acts through the cam-groove in the feed-wheel to reverselv turn the stitch-forming n'iechanisn'l 180 I it rted by the arrow, Fig. 4:, to restore as inn it to star-ting position. As the turret 13 reaches .initial position, carrying the nipperjaw 57 directly over the aw 59, the 0 11111 portion 53 in the gear 25 effects the quiet ad ance and closure of the scissors 41, 44,-, l? 6, to cut the cord close to the end or the button-hole. As soon as the cord s cut the buttonhole cutting mechanism is tripped into action and, during the advance o t the cutter fulcrum blocli 35, the aws 59, 54, are closed upon the cord and the shoulder 66 en gages the cord, Fi gs. 8 and 9, and pulls back the cord end, leaving the cord slack between the needle-throat member 12' and the nipper-jaus 5T, 59. l Vhen the buttonhole cuttor-levers are retracted, the nippedaws 54, 59 are opened. I

[it the start of the next sewing operation the initial stitches are formed so close to the beginning end of the cord that subsequent i'eti-in'in'iing of such cord end is not required. T he slackness in the cord between the spring 58 and the needlethroat member permits the cord to run with the utmost freedom until the beginning cord end is safely bound by the initial stitches and all danger of such cord end slipping relative to such stitches is past. v

Having thus set forth thenature of the invention, what I claim herein 1s 1. in a sewing machine ot the buttonhole type, stitch-forming mechanism, a workholder, means for relatively moving them during the sewing, a cord guide for delivering a cord within the range of action of the stitch-forming mechanism, means for relatively moving the stitch-fornnng mechanisni and work-holder out of sewing relation subsequent to the sewing operation, means for severing the cord, and pos tively actu ated means out of strain-exerting engagement with the cord during the sewing for pulling back on the cord between sewing periods to shorten the severed cord end.

2. In a sewing machine of the buttonhole type, stitch-forming mechanism, a. workliolder, means for relatively moving them during the sewing, a needle-throat member, a cord-guide for delivering a cord within the range of action of the stitcl1-forming mechanism, a cord-nipper open during the sewing, means for closing said nipper on the cord subsequent to sewing, and a cord pullback device out of strain-exerting engag ment with the cord during the sewing and acting on the cord between said nipper and said needle-throat member after the nipper has been closed.

3. In a sewing machine of the buttonhole type, stitch-forming mechanism, a workholder, means for relatively moving them during the sewing, buttonhole cutting mech anism, a cord guide for delivering a cord within the range of action of the stitch- :lorming mechanism, means for relatively moving the stitch-ilorming mechanism and worleholder out of sewing relation subsequent to the sewing operation, means for severing the cord, and means connected to be operated by the buttonhole cutting meclr anism for pulling back on the cord to shorten the severed cord end.

4-, In a sewing machine of the buttonhole type, stitchforming mechanism, a worle holder, means for relatively moving them during the sewing, a cord-guide for delivering a cord within the range of action of the stitch-forming mechanism, means for relatively shifting the stitch-forming mechanism and work-holder out of sewing relation, means for severing the cord between the cord-guide and the last stitch, a cord-nipping device ineffective during the sewing. a cord pull-back device, and means common to said cordnipping and pull-back device for operating them at a predetermined time between sewing periods.

5. In a sewing machine of the buttonhole type, stitch-forming mechanism, a work holder, a sewing shaft and connections for relatively moving the stitch-forming mechanism and worleholder during the sewing, a cord-guide for delivering a cord within the range of action of the stitch-forming mechanism, a. cord-cutter, a second shaft stationary during the sewing with means for driving it between sewing periods, and means mechanically connected to be driven by said second shaft for pulling back on the cord to shorten the severed cord end.

6. In a sewing machine of the buttonhole type, stitch-forming mechanism, a workholder, a sewing shaft and connections for relatively moving the stitch-forming mechanism and work-holder during the sewing, a cord-guide for delivering a cord within the range of action of the stitch-forming mechanism, a cord-nipper, a cord-cutter, a second shaft stationary during the sewing with means for driving itbetween sewing periods, and means mechanically connected to be driven by said second shaft for actuating said cord-nipper and for pulling back on the cord to shorten the severed cord end.

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7. In a sewing machine of the buttonhole type, stitclrforming devices including upper thread mechanism, under thread mechanism, a rotary turret carrying the under thread mechanism, a cord guidecarried by said turret, a work-holder, means for relatively moving the stitch-forming mechanism and work-holder during the sewing, a cord-nipping device including coacting jaws one of which is carried by said turret and the other of which is mounted independently of said turret, said jaws being cooperatively related when the turret occupies a predetermined position, and a cord pull-back device adapted to act on the cord between said nipping from buttonhole cutting position, means for shifting the work-holder from sewing to buttonhole cutting position, a cord-cutter, and a cord pullback device connected to be operated by the travelling movement o'f said buttonhole cutter fulcrum block.

9. The combination set forth in claim 8 with a cord-nipping device also connected to be operated by the travelling movement of said cutter-carrying fulcrum block.

, 10. In a buttonhole sewlng machine, the combinatlon with stitch-forming mecharesting device, and a cord pull-back device between the cord-teed arresting device and the needle-throat member, both of said de vices being out of strain-exerting engagement with the cord during the sewing.

- 11. In a buttonhole sewing machine, the

combination with stitch-forming mechanism, a work-holder, and vmeans for relatively mov ing them tov sew about a buttonhole, of a needle-throat member having a cord-guide, a cord-cutter operating at the close of a sew ing operation, a cord pull-back element, and automatic means including a driving shaft mechanicallyconnected to the cord pull-back element for moving the latter intermediate sewing periods. V

v 12. In a machine of the buttonhole type, overseaming stitch-forming mechanism, a cord-guide for delivering a cord entirely within the overseam produced by said stitchforming mechanism, a cord-cutter, and cordengaging means having cord pull-back and slack-giving motions between sewing periods for pulling a measured length of cord back through the cord-guide and for pro ducing slack in the cord before the start of the next sewing'period to obviate the denger of slippage of the cord relative to the initial stitches.

In testimony whereof, I have signed my name to this specification.

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