US2264036A - Tension-releaser for sewing machines - Google Patents

Description

Nov 25, 1941. H. c. FAULKNER 2,264,036

TENSION-RELEASER FOR SEWING MACHINES Filed Feb. 29, 1940 7 Sheets-Shetl w: 3mm gm ommzd a Sawlnef Nmi. 5, 1941. c, FAULKNER I 34$ ITENSION-RELEASER FOR snwme monmm Filed Feb. 29 1940 '1 sheets-sheet 2 gwvw Nov. 25, 1941.

H. c. FAULKNER 2,264,036 TENSION-RELEASER FOR SEWING MACHINES Filed Feb. 29, 1940 7 Sheets-Sheet s (fibroid CZ yaulner Nov. 25, 1941. H; guLKNgR 2,264,036 v TENSION-RELEASER FOR SEWING MACHINES Filed Feb. 29, 1940 "7 Sheets-Sheet 4 H. C. FAULKNER TENSION-RELEASER FOR SEWING MACHINES Nov. 25, 1941'. I

'7 Sheets-Sheet 5 Filed Feb. 29, 1940 grwq/rvbom J/arold 6f gazelner Nov. 25, 1941. H. c. FAULKNER TENSION-RELEASER FOR SEWING MACHINES Filed Feb. 29, 1940 7 SheetS-ShQefL G Nov. 25, 1941. H, c, FAULKNER 2,264,036

TENSION-RELEASER FOR SEWING MACHINES Filed Feb. 29, 1940 7 Sheets-She'et 7 Patented Nov. 25, 1941 'JFENS'ION-REIJEASER FOR MACHINES Harold .C. Faulkner, Bridge ort, Gonn.,.,as signor .to The Singer .Manufacturing Company, Elizaboth, N. J., a corporation of New Jersey Application February 29, 1M0, Serial No. :32L1i95 4 Claims.

This invention relates to tension-releasers for sewing machines of the type represented in U. S. Patent No. 2,16%);016, dated July 4, 19.39. v

According to the patented construction the .tension-releaser is operated by the clutch-mechanism which controls the .rapidafeed mechanism of :the machine, vso that the .tension is released when the rapid-feed is :thrown in and is restored when the rapid-feed is thrown out. This sarrangement is satisfactory in a buttonhole machine which rapid-feeds only at the beginning and end of a buttonhole-producing cycle .for the purpose of rapidly moving the work-clamp from buttonhole cutting position into sewing position .and from sewing position back .to buttonholecutting position.

in some machines, however, .there is mechanism for throwing in the rapid-feed when .the .sewing reaches the eye-end of the buttonhole and for throwing out the rapid-feed after the eye-end has been stitched, so that the eye or endstitches of the buttonhole :not epile upon one another at said end. By the eye-end of a buttonhole 1 mean the end remote from :the :beginning end where the initial and final stitches are custom.-

.arily laid. in some buttonholes the stitches :at the eye-end are laid :radially :around an open :hole in the work at one end of :the buttonhole slit and .form an open eyelet at this en'clsof the buttonhole. In :other huttonholes, such as are commonly used-in coatlap'els,1the stitches :at the eye-end are laid :radially about the .end of the buttonhole slit and do not .definean open eyelet. It is in sewing these .buttonholes of the coat- .lapel type that piling of the radial end stitches occurs unless the;rapid-feed is thrown in while :such stitchesare being sewn. The patented tension-releaser above cited will not meet the con- ;dition in sewing and rapid-feeding .around the .eye as the tension on the thread is released'when. ever the machine is rapid-feeding, whereas, to meet the condition 'in question, the tension should not be released :at any time during :the sewing period.

According to the present invention, :the :operative connection between the rapidefe'ed .clutchoperator and the tension-release'lever isdisabled by the stop-motion control :mechanism, "whenever the machine .is sewing. Thus,1the machine may rapid-feed while sewing around .the:.eye.end of the buttonhole 'illIldEl :anormal tension. "The operation of the rapid-feed clutch-operator .will

:have no action on .the tension-.releasenwhile the .machine is sewing. This provision ;also takes care of the desired releaseof .theztension while '55 lowz'box-like rapid-feeding around the eye end of a buttonhole in machines where the .stitch ionmingimech n sm ,is :stopped at the end of the first side-stitchin operation and started again at the beginnin -m the .second side-stitching operation :on a button.- hol-e toeliminate therradialendestitches.

:I-n the accompanying dnawingsif'is. 11 :is a right :side elevation {of re. buttonhole sewing machine embodying the invention. Fig. :2 is :a left side elevation of :thezmaehine. Fig-3 :is is. bottom plan view. .Fig. 41 is :a rear end elevation, earth section. Fig. :5 is an inner iface new of the-nattern-wheel of the manhine showing the trippin :points :and Hatches tor {controlling the amid-teed crossesiide-nod the-machine. .Fl i6 is a iae .spective view of the lower end of the =tensinnrelease lever associated with theranidfeed-mntrollin cross-.s-lide-rod and the venom-Wh l which controls the @period .of operation of the stitch-forming mechanism. fie. :H is :an outer face view of the pattenn-wheel. .Fi-g. :iS a se tion on the iine:8-.-;8, '17.. .Fig. 9 :is;a itopwiew :of :the pattern-wheel With the .stop mQ-t Qn-Qimtroliing .eametraok-iol-lower lever in section and :showing ztlreldisabling arm for tensionemeleas ins thrust-her. i-Fies. i0 and ill :ane :firasmentan/ perspective wiews of the patternewheei with :a stop-:motionecontrolling 3Xi'l-1t1130k eyeesectien .shiited, respectively, to openatiue andrinoperetive position. .Fig. is arad-lalisectionthrough the anattern wheel sinthe region of the-shiftabl st p- .motioneoontrol icametrac k section. :Fie. 211 is a viewofthepaitsshown in'Fi-g. :6 atzthe neriod of a buttonhole-producin cynic when the -.rapi.d- :leed @is thrown Kill to carry the monk 1mm buttonhole-cuttingmosition tosewin rposition. Big. 14 is .a similar view "of the parts immediate y prior :to the start nf a s win neri d, showing the tension-release zthrust har fsmfl' fiditQ disabled p sition; the .ranid-ifeed .still fleein zon- Eis- 211 is .-a similar wiew .of the parts when the machine sewing and :after the mapideieed has :been

thrown nut. fig. ,116 .is .;a horizontal seotion sub.-

:stantiall on the -1ine tit-15. fig. eiiatzthe :stalt of a buttonhole-producing cycle, theisaimezas in 6. Fig. 1.7 .isia :vieW s'imilarto F g. 11:5 tilt t the -.period of the cycle represented in :Elg. 3 :18 is a .planwview KIFfifihGttBIISiQDeIiGlBESQI' connections on top .of the .sewing machine brackeh arm. fig. .19 :issa sectionnn theiline .|19e:l:9.,.sF 1.8, and Big. is .a section on thezline 120*520,

.In :the znrefenned embodiment of the invention illustrated, the machine-frame oommtises .a .rholihed I from rone endcof whicnrri'ses the standard 2 of the overhanging bracket-arm 3 terminating in the head 4.

The stitch-forming mechanism is of the well known type embodying an upper endwise reciprocatory and laterally vibratory needle 5 and under thread mechanism constructed substantially in accordance with the disclosure of U. S. Patent No. 1,372,473,.dated Mar. 22, 1921, and comprising a turret 6, Fig. 1, which is turnable about a vertical axis and carries threaded and non-threaded loopers, the former of which is shown at 1, and a pair of loop-detainers one of which is shown at 8. The needle-actuating mechanism is also mounted to turn about a vertical axis coincident with the axis of the turret and the usual turning movements are imparted to the upper needle andunder looper mechanisms by the connected upper and lower sector gears 9 and [9, respectively, which are actuated in unison by the usual connections with the cam-groove l I, Fig. 3, in the feed-cam" [2. This well known mechanism is: more completely shown, for example, in U. S. Patents No. 1,162,207, Nov. 30, 1915; No. 15,324, reissued Apr. 4, 1922,

andNo. 1,534,017, Apr. 21, 1925. The mechanism operates to rotate the stitch-forming devices in one direction during the sewing around the eyelet-end of a buttonhole and to reversely rotate the stitch-forming devices between sewing periods to'restore them to initial position. The

stitch-forming devices are actuated from the main sewing shaft I3 which also drives the feedcam 12 in step-by-step fashion, during the sewing, through the well known pin-and-star-wheel drive l4, Fig. 3, and the usual 'train of gears l5,

such as more completely shown in said U. S.

Reissue Patent No. 15,324.

The work-clamp is of the travelling type. It is first rapidly moved over the bed I to carry the work forwardly from initial or buttonholecutting position to stitching position, then more slowly moved in step-by-step fashion to place the stitches about the buttonhole, and" then rapidly returned to initial position. It is constructed substantially in accordance with said U. S. Reissued Patent No. 15,324 and comprises the lower clamp-plates l6 and upper clamping 'feet I! which are depressed into clamping engagement with the work by a rocking movement of two connected coaxialrock-shaft sections 18,

-18 to the former of which is connected an arm l9,' Fig. 1, adapted to be depressed by the usual clamp-closing lever 20 actuated at the beginning -of a buttonhole-making cycle by a cam-groove 2|, Fig. 4, in a continuously running pulley 22 loose on the buttonhole-cutter shaft 99. A slidepin 23, carried by the rearwardly extending arm 24 of the clamp-closing lever, is permitted to enter the cam-groove 2| for one revolution of the pulley 22, whereupon it is ejected and latched in ejected position, as explained in U. S. Patent No. 1,832,665, Nov. 1'7, 1931; the present clamp-closing mechanism being constructed substantially in accordance with the disclosure in said U. S. Patent No. 1,832,665.

The clamp-plates l6 are carried by the crossslide plate 24', Fig. 3, which, in turn, is carried by the longitudinal slide-frame 25 to which travelling movements are imparted by the linkconne'ction 26, Fig. 3, with the longitudinal feedlever 21'having a. follower working in a longitudinal feed-cam groove in the feed-cam wheel 12. The cross-slide plate 24' is shifted by the lever 28, Fig. 3, which has the usual connections with the feed-cam l2 and removable patternnose 4! and does not engage the latter.

wheel 29 on the cross-shaft 30 which is geared at 3|, Fig. 1, to the feed-cam I2, so as to run with the latter. The present feed-mechanism is constructed substantially in accordance with the disclosure of said U. S. Reissue Patent No. 15,324.

The period of operation of the stitch-forming mechanism is controlled by the conventional startand stop-lever S which carries a stoptooth 32 adapted to enter a stop-notch 33 in the stop-cam 34 on the sewing shaft 13. The stop-lever S is carried by a rock-shaft 35 which, when turned to swing the lever and its stoptooth 32 rearwardly from the stop-cam, effects the coupling thereto of the constantly running belt-driven pulley 36 through a conventional clutch-mechanism (not shown). This startand stop-control mechanism is the same as that shown in said U. S. Patent No. 15,324; reissued Apr. 4, 1922. To operate the startand stopcontrol lever S, the rock-shaft 35 has fixed thereto an arm 31 which is connected by a link 38 to a lever 39.which is pivoted at 40 on the bed I and has a nose 4| which rides on the cam-track 42 of the pattern-wheel 29. This cam-track 42 has high and low circular portions which are separated by the start-sewing cam-rise 43 and the stop-sewing drop-off shoulder 44, as is fully explained in said reissued patent.

In the pattern-wheel 29 of the present machine, however, the cam-track 42 has a shiftable plate-section 45 which is movable axially ofthe pattern-wheel 29 to carry it fromits full line or operative position, Fig. 12, to its dotted line or inoperative position. When in full line position, the plate-section 45 of the cam-track 42 bridges the gap between the supplemental start-sewing cam-rise 46 and stop-sewing shoulder 41, Figs. 10 and 11, and renders these ineffective. When the'plate 45 is shifted to dotted line position, Fig. 12, which is the position shown in Fig. 11, the plate 45 is carried to one side of the follower- Thus the cam-rise 4B and shoulder 4'! are rendered operative upon the follower-nose 4| and the sewing is stopped at the end of the first side-stitching operation on the buttonhole and started again at the beginning of the second side-stitching operation; the stitch-forming mechanism being stopped while the machine is rapid-feeding around the eye-end of the buttonhole.

The plate 45 is carried by the slide-shaft 48 of the knob 49 and is steadied by the pins 50 which are fixed in the body of the pattern-wheel 29. The plate 45 is confined in either of its two positions by the spring-influenced latch-lever 5|, see particularly Fig. 12. Thus the machine may be quickly converted from one which sews around a worm-and-gear reduction 53, Fig. 1, drives the live element 54, Fig. 3, of a clutch, the driven element of which is fast on the cross-shaft 30.

It will be understood by referring to said U. S. Reissue Patent No. 15,324 that the withdrawal of the cone 56 from the driven clutch-element 55 effects engagement of the driving and driven clutch-elements 54, 55, while projection of the cone 56 toward the driven clutch-element 55 effects the de-clutching of the parts 54, 55. 'The accrues cone 5 is-actuated-by the usualarm 5'! rigidly mounted on the cross-slide rod 58 and carrying the lateral-pin-is and latching'block 60, Fig. 4.

As disclosed in U. S. Patent- No. 1,548,815, Aug. 11, I925, there is mounted in the base I on the bracket 6!, a continuously rocking bell-crank lever 62, 6-3, the forked arm 62 of which embraces a. crank 64. on the rapid-teed shaft 52 Pivoted on the arm 63 is a single reciprocating bar 85 the free end of which has connected to it a spring 66, which pulls the bar 65 upwardly against. the seat 61 of the latch 68, Fig. 5E, pivoted at 69 on thebed i. The bar 65 reciprocates idly when held down by the latch 68. When the latch 68 is swung on its pivot 65 to release the bar [$5, the latter is drawn upwardly by the spring Miami the shoulder I50, Fig. 4, engages the pin 59 and pushes the cross-slide rod 58- to the right against the. resistance of the recovery spring It to withdraw the cone 56 from the clutch-element 55 and onset. the coupling of the rapid-feed shaft 5-2 tothe cross rotary shaft 30 to. drive the feed-cam [2 at its rapid rate. When the slide-rod 58 is pushed to clutch-engaging position, it is. held there by engagement of the shoulder I2, Fig. 4-, on the lever 3 with the latch-block E; the lever 13 being biased upwardly about its fulcrum M by the spring t5. Thus, the lever i3 and shoulder 12 act as a spring-latch to hold the slide-rod 58 in clutchengaging or rapid-feed position. During the return movement of the bar 65 the inclined shoulder i6, Fig. 4, engages the pin 55 and causes the bar 55 to be depressed sufiicientl-y to be reengaged' in idling position by the latch-lever 68'.

The pattern-wheel 29 which is removably carried by the cross rotary shaft 30 and operates the stop-motionlever S through the lever 39- and link 38 to control the period of action of the stitchforming: mechanism, also adjustably carries, on its. inner face, the tripping points M, It andJ'Ifl, Fig. 5, which tilt the lever 80 and control the throwing out of the rapid-feed drive for the feed-wheel I2. The lever 80 is forked at one end to embrace the end 8I of the latch-lever I 3. Hence, when the lever 88 is tilted by one oi the tripping points 'II'II, i8; I9, the latch-lever T3 is depressed and the slide-rod 58 released, whereupon the spring I I on the slide-rod. 58 acts to shift the slide-rod from rapid-feedrunning position, Fig. I7, to rapi'd feed' stopping ordeclutchi ngposition, Fig. 16'.

Tripping point TI throws out the first rapidfeed motion of the work-clamp from starting position when the work-clamp reaches sewing position. Tripping point '18 throws out the rapid-feed at the eye, when used, and tripping pomt I9 throws out the final rapid-feed when the work-clamp is returned to starting position.

The controlling mechanisms for initiating the rapid-feed prior and subsequent to the sewing period are substantially the same as those disclosed in U. S. Patent No. 1,548,815 and comprise the rock-shaft 82, having an arm 83 engaging the latch 68, another arm 8 adapted to be depressed by operation of the depending arm 85 of the clamp-closing lever, and a third arm 8% adapted to be elevated by the pawl 81 actuated by vertical motion of the stop-tooth 32- of the stop-motion device S.

The present machine is'of the cut-after type, that is, it cuts the buttonhol'e after stitching it. The buttonhole-cutting mechanism is. conventionaland embodies the travelling buttonholecutter levers 88, 89-, Fig. 2, which are given their customary travelling and closing-and-opening movements by suitable cams on the cutter-shaft 9:0 to which a. single rotation is imparted prior to stitching by the continuously rotating pulley 22 acting through the usual one-revolution clutch on the clutch-disc SI.

The present machine has mounted on top of the standard and bracket-arm a housing 92' for a take-up cam 93 which is mounted on a shaft 94 driven by the top-shaft 95 which actuates the needle-bar '96 in the usual manner. Pivotally mounted at 9 in the housing 92 is the take-up lever 98- carrying a follower roll 99 which enters the take-up cam-groove 93. The take-up lever 98 has at its free end a thread-eye I00 which acts upon the needle-thread between the tension-device IIJI and the hollow needle-bar 95 through which the needle-thread runs to the needle 5. The course of the needle-thread is the same as shown said U. S. Patent No. 2,165,016. The tension-device IN is conventional and, in addition to the two tension-disks IflI', comprises the arbor I-Il2= on which the tension-disks IIJI" are mounted. The arbor has adiametrical slot I03 at one end topass the diameter-bar I04 of the pressure-head "15 against which one end of the beehive-spring Hi6 rests; the other end of such springbeing engaged by the adjustable thumb-nut I01. The arbor I92 has in its unslotted end an axial hole to admit the tensionrelease pin IIlB- which, at times, engages the diameter-bar Hi l of the presser-head I95 and pushes the latter away from the tension-disks I-IiI' to release the tension on the needle-thread. The tension-release pin IilS- is in position to be engaged by one end of the lever I09, Fig. 18, fulcrumed at II-Il on the under side of the cover I II for the take-up housing 92'. The lever I 09 has at one end a bent up tongue I I2 in position to be engaged by the head of the screw H3 adjustably threaded into the upper end of the tension-release lever II-4 which is ful-crumed at II5 to a bracket I- IB mountedonthe left side of the bracket-arm standard 2-. The tension-release lever II- i also has onit a cam-follower nose H I which, at times, is engaged by'a tension-releasing camblock H8 ad-j-ustably mounted on the rod H9 connected to the longitudinal slide-frame 25 of the work-clamp;

The tension-release lever IM has fastened to it a downward extension I 2 iihaving an offset lower end portion I2'I- that terminates-above the outer end of a thrust-bar I=2-2 which is freely pivoted on the pin 59 carried by the rapid-feed clutchcontrolli-ng cross-slide rod 58. The thrust-bar I22 has at its upper edge a thrust-shoulder I 23 which, at times, engages the lower end of the tension-release lever II4-I 2il'-I2 I and moves it in a direction to releasethe tension. The thrust-bar I22 is tied by a spring I24 tothe offset lower end I-2-I of the tension' release leveryso that the thrust-bar is spring-urged upward-1y at all times. The lever- 39- whichcarries the camtrack-follower nose- 41 also has fixed thereto an arm- II'25' that overhangsthe' freeend of the thrust ba-r- I2*2- and, when the fol-lower nose 4t is riding on the high part of the cam-track 42 or, in other words, when thesewing mechanism is in operation, the thrust-bar I22 isdisabled or held by the arm I25 in a depressed position out of possible engagement with the tension-release 'Iever' I*I 4'-I-2i'I2-'I-. f r 7 I The present machine is fitted with a device, such as represented in the U. S; patentapplicm tiorrofEdward P. Spaineand Ha-roldC. Faulkner;

Serial No. 243,126, filed Nov. 30, 1938, for tripping the rapid-feed into action when the sewing operation reaches the eye-end of the buttonhole. To this end there is fixed to the rock-shaft 82 an arm I26 which is within the range of travelling movement of the tripping point I21 on the block I28 carried by the rod II9. At the end of the first side-stitching operation on the buttonhole, the tripping point I21 engages and depresses the arm I26 thus releasing the latch 68 from the rapid-feedeclutch-controlling push-bar 65 and throwing in the rapid-feed. The tripping point I21 may be turned to an inoperative position and held there by the latch I28, when so desired, as explained in said copending application.

Operation At the beginning of a buttonhole-producing cycle the tension-release lever I I4 is held in tension-release position by the block H8, Fig. 16, which at that time is under the nose II! of that lever. Also, the shoulder I23, Fig. 6, of the thrust-bar I22 is spaced inwardly from the ofiset lower end I2I of the tension-release lever. The thrust-bar I22 is, however, held by the spring I24 against the lower end I2I of said lever.

When the machine is started the clamp-closing lever 2485 is first given its usual rocking impulse and, during the recovery motion of this impulse, the arm 85 depresses the arm 84 of the rock-shaft 82 and trips the rapid-feed into action. When the slide-rod 58 is moved from the position of Fig. 6 to the position of Fig. 13, to throw in the rapid-feed, the shoulder I23 of the thrust-bar I 22 is moved up to the tension-release lever-end I2I to hold the tension released after the rapid-feed of the work-clamp has carried the block H8 out from under the nose II! of the tension-release lever. The rapid-feed continues until the workclamp has been carried to sewing position whereupon the start-sewing cam-rise 43 of the pattern-wheel cam-track 42 engages the nose M of the follower-lever 39 and shifts the stop-lever S to start the stitch-forming mechanism. The

shift of the lever 39 by the cam-rise 43 causes the arm I to depress the thrust-bar I22 to its ineffective or disabled position, Fig. 14, and release the lever lI4-I2il-I2I, thereby restoring the tension on the needle-thread. At the same time the tripping point I! on the back of the pattern-wheel throws out the rapid-feed.

Assuming that the cam-track plate-section is set in full line position, Fig. 12, so as to engage the follower-nose 41 to continue the sewing around the eye-end of the buttonhole, the sewing will progress all the way around the buttonhole without being stopped. The rapid-feed will be thrown in at the eye of the buttonhole by the action of the tripping point I21 but will have no effect upon the thread-tension for the reason that the tension-releasing thrust-bar I22 is held disabled by the arm I25 on the pattern-wheel cam-track follower-lever 39, as shown in Fig. 15. At the completion of the sewing period, the nose 4| on the lever 39 drops off; of the stop-sewing pattern-wheel cam-track shoulder 44 and releases the thrust-bar I22 whichis immediately restored by the spring I24 to operative position. The rapid-feed is now tripped into action by the pawl 81 associated with the stop-motion device S and the action of the rapid-feed-starting slide-rod 58 causes the thrust-bar I22 to move the lever II4-I2Il-l2I and release the tension. The movement of the work-clamp back to starting position carries the cam-block II8 back underthe nose ,I I1 of the tension-release lever II4 to hold the tension released after the rapidfeed clutch-controlling slide-rod has been moved back by the spring II to stop the rapid-feed at the completion of the buttonhole-producing cycle.

The cam-block H8 is of sufficient width to hold the lower end I2I of the tension-release lever slightly spaced from the shoulder I23 of the thrust-bar I22, as shown in Fig. 13. The link 38 of the stop-motion control mechanism has a toggle-section 38', Fig. 2, with a handle 38" whereby the toggle may be broken to withdraw the lever 39 and its cam-follower nose 4| sufficiently to permit the pattern-wheel 29 to be readily removed from and replaced on its shaft 30. This toggle-device is substantially the same as that disclosed in said U. S. Patent No. 1,548,815.

When the toggle-link 38' is manipulated to swing the lever 39 rearwardly for removal of the pattern-wheel 29, the arm I 25 on the lever 39 depresses the thrust-bar I22 to an inefiective position. When the pattern-wheel 29 is replaced and the toggle-link 38' is restored to its initial position, the lever-arm I25 is elevated and releases the thrust-bar I22 which is restored by its spring I24 to its original position with the shoulder I23 in position to be engaged by the tensionrelease lever end I2I when the cam-block H8 is carried .out from under the lever-arm II4.

If it is desired to omit the sewing at the eye of the buttonhole, the pattern-wheel cam-track plate 45 is shifted to dotted line position, Fig. 12, where it does not engage the follower nose 4|. This shift of the plate 45 renders operative the supplementary stop-sewing shoulder 41 and startsewing cam-rise 46. Under this adjustment the sewing mechanism will be stopped and the rapidfeed thrown in when the eye is reached. The tension will also be released. After rapid-feeding around the eye, the rapid-feed will be thrown out, the tension will be restored and sewing will be resumed.

The pattern-wheel 29, follower-lever 39, link 38 and lever S constitute automatic means (A), Fig. 6, to start and stop the stitch-forming mechanism, while the spring influenced thrust-bar I22 constitutes means (B) actuated by the rapidfeed-controlling mechanism or cross-slide rod 58 for operating the tension-release lever II4I20I2I to release the tension IIII while the rapid-feed is in operation. The arm I25 fixed to the follower-lever 39 constitutes means governed by automatic means (A) for disabling means (B) while the stitch-forming mechanism is in operation.

Having thus set forth the nature of the inven-- tion, what I claim herein is:

1. In a sewing machine of the buttonhole type having stitch-forming mechanism, a stop-motion device therefor automatic controlling mechanism for the stop-motion device, a work-holder, stitching-feed mechanism for relatively moving the stitch-forming mechanism and work-holder in sewing around a buttonhole. rapid-feed mechanism for relatively moving the stitch-forming mechanism and work-holder at a faster speed during portions of a buttonhole-producing cycle, controlling means for the rapid-feed mechanism, a sewing thread tension-device, and a tensionreleaser operatively connected to the controlling means for the rapid-feed mechanism, the improvement which consists in the provision of means operated by the stop-motion controlling mechanism to disable the operative connection between the tension-releaser and the rapid-feed controlling mechanism whenever the machine is sewing, so that the thread-tension will not be released while the machine is sewing, in case the rapid-feed is thrown in during a portion of the sewing period to avoid overcrowding of stitches.

2. A buttonhole sewing machine having stitchforming mechanism, a stop-motion device therefor, a pattern-wheel having a cam-track, a follower-lever acted upon by said cam-track and connected to the stop-motion device to control the period of operation of the stitch-forming mechanism, a work-holder, stitching-feed mechanism for relatively moving the stitch-forming mechanism and work-holder in sewing around a buttonhole, rapid-feed mechanism for relatively moving the stitch-forming mechanism and work-holder at a faster speed during certain periods of a buttonhole-producing cycle, a rapidfeed clutch for starting and stopping the rapidfeed, a clutch-operating slide-rod, a threadtension device, a tension-release lever terminating adjacent one end of said slide-rod, a thrustbar connected to said slide-rod and adapted to engage and shift said tension-release lever to release the tension when the slide-rod moves to throw in the rapid-feed, and an arm on the stopmotion-controlling cam-track-fo1lower-lever arranged to hold said thrust-bar in an inefiective position when said follower-lever is shifted in a direction to start the sewing operation.

3. In a buttonhole sewing machine, stitchforming mechanism, a thread-tension device, automatic means (A) to start and stop the stitchforming mechanism, a work-holder, stitchingfeed mechanism to relatively move the stitchforming mechanism and work-holder in sewing about a buttonhole, rapid-feed mechanism and automatic controlling means therefor to relatively move the stitch-forming mechanism and work-holder at a faster speed during certain periods of a buttonhole-producing cycle, means (B) actuated by the rapid-feed controlling mechanism to release said thread-tension device while the rapid-feed is in operation, and means governed by said automatic means (A) to disable said means (B) whenever the stitch-forming mechanism is in operation.

4. A buttonhole sewing machine having stitchforming mechanism, a work-holder, stitching feed mechanism to relatively move the stitchforming mechanism and work-holder in sewing about a buttonhole, rapid-feed mechanism to relatively move the stitch-forming mechanism and work-holder at a faster speed during certain portions of a buttonhole-producing cycle, a shiftable member ,to control the starting and stopping of the rapid-feed mechanism, a threadtension device, a tension-release lever, a thrustbar pivotally carried by said shiftable member in position to engage and operate said tensionrelease lever, automatic stop-motion mechanism to control the period of operation of the stitchforming mechanism, and means controlled by said stop-motion mechanism to shift said thrustbar to an inefiective position whenever the stitchforming mechanism is in operation.

HAROLD C. FAULKNER.

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