US2426636A - Sewing machine - Google Patents

Description

' T, E. MONROE SEWING MACHINE Filed Feb. 2, 1943 6 Sheets-Sheet 1 INVENTOR BY 1 j fiQRNEYgQ Sgpt. 2. 1947. O RQE 2,426,636.

SEWING MACHINE 7 Filed Feb. 2, 1945 6 Sheets-Sheet 2 lea I i I INVENTOR 790m ff/Vonwus BY 2%) 7/ AT OR Y p 1947- 1 E. MONROE 2,426,636

I SEWING MACHINE Filed Feb. 2, 1945 6 Sheets-Sheet 4 E [@JLEJEEE INVENTOR fi o/v4.95 /V0/v/?a BY y// ATR SRNEYS Sept. 2, 1947. -'r. E. MONROE 2,426,636

SEWING MAcHiNE I Filed Feb. 2', 194a e Sheets-Sfiet 5 INVENTOR flames [/70/Vfi05 /7 a; ///ATTRNEYS I I Sept, 4 T. E. MONROE I I 2,426,636

SEWING MACHINE Filed Feb. 2; 1943 6 Sheets-Sheet 6 r A ;;%RNEYS Patented Sept. 2, 1947 SEWING MACHINE Thomas E. Monroe, New York, N. Y., assignor of one-half to William R. Donaldson, Northport, N. Y., and one-fourthto William R. Donaldson, as trustee; William R. Donaldson administrator of said Thomas E. Monroe, deceased Application February 2, 1943, Serial No. 474,451

32 Claims. (Cl. 112-98) This invention relates to sewing machines.

It is an object of the invention to provide a machine which produces a chain stitch having improved locking characteristics.

It is a further object of the invention to provide a machine which produces such a stitch in which the loops of the successive stitches are of varying lengths.

It is a further object of the invention to provide improved mechanism for producing a multiple chain stitch, or stitch in which the successive loops are taken from different threads.

It is a further object of the invention to provide a machine which, without sacrificing simplicity and reliability of construction and operation, provides a considerable range of variations in stitch sequence and in stitch length.

Still another object of the invention isto provide improved fabric feeding and thread handling mechanism for sewing machines.

In certain aspects, as will appear more specifically in the following description, the present invention constitutes an improvement upon the disclosures of my previous patents, Nos. 2,152,203, issued March 28, 1939, and 2,206,484, issued July 2, 1940 and my patent applications Serial No. 322,867, filed March 8, 1940, and Serial No 373,976, filed January 10, 1941, as a division of the last mentioned application. Both of those applications were co-pending withthe instant application and were abandoned after the filing of patent applications Serial No. 559,580 and Serial No. 559,579, both filed October 20, 1944, as continuations respectively of the two first mentioned applications and both co-pending with the instant application.

The claims of the present application are directed to the machine disclosed herein, the improved methods of stitching forming the subject matter of my application Serial No. 474,450, filed February 2, 1943, for Stitch and method of stitching.

With the foregoing general objects in view and stillbthers which will appear in the following full description, the invention consists in the combinations and arrangements of parts and details of construction which will now be fully described in connection with the accompanying drawing and then more particularly pointed out in the appended claims.

In the drawing:

Figure 1 is an elevation view of a sewing machine embodying the invention in a preferred form, and is taken looking forwardly or in the direction of fabric advance, certain casing parts having been broken away to show internal mechanism;

Figure 2 is an enlarged view of a thread feeder or looping member of the machine in Figure 1 together with certain associated operating mechanism therefor;

Figure 3 is'a vertical cross section taken on the line 3-3 of Figure l;

Figure 3A is a detail plan view of the needle hole;

Figure 4 is a plan view'of the control mechanism shown in Figure 3;

Figure 5 is an enlarged cross section taken on the line 5-5 of Figure 4 and showing certain adjustable cam mechanism for controlling the operation of the thread feeding mechanism;

Figure 6 is an enlarged cross section taken on the line 6-6 of Figure 4 and showing the drive mechanism for the needle-bar and feed-foot bar of the machine;

Figures 7 and 8 are detail cross section views of a hollow shaft shown in Figure 6 and showing sections thereof where the same is cut out to accommodate certain regulating mechanism by means of which stitch length is controlled;

Figure 9 is a section taken on the line 99 of Figure 3 and showing the regulating mechanism for varying the stitch length;

Figure 10 is a view on an enlarged scale of a portion of Figure 1, and with parts removed so as to show more clearly a portion of the drive mechanism thereof for operating the needle-bar and feed-foot bar and for controlling the thread feeding mechanism;

Figure 11 is a view similar to Figure 10 but with parts removed so as to show the main worm drive and one-way clutch of the machine;

Figure 12 is a view in exploded perspective of the parts of Figure 10 which comprise the ad- J'ustable cam forcontrolling the thread feeding mechanism;

Figures 13 and 14 are views showing this adjustable cam in the position of Figure 10 but illustrating two different conditions of adjustment;

Figure is a view looking in the direction of the line 15-45 of Figure 3 and showing further the mechanism for regulating stitch length and for producing varying length stitches;

Figures 16 and 17 are respectively plan and section views showing schematically a double chain stitch such as may be produced from two threads by the machine of Figure 1;

Figures 18 and 19 are similar views showing an alternative stitch producible by the machine and in which three suc'cessive loops {are taken from one thread for every loop taken from the other;

Figures 20 and 21 are views showing a single chain stitch which may also be produced by the machine;

Figure 22 is a section view similar to Figure -1 7 but showing a double chain stitch with varying length loops; v

Figure 23 is a View sirrii showing a single chain stith'with varying-1e loops;

Figures 24 to 27, inclusive,=are'sch'eiiiatic views on an enlarged scale taken on the line 14- 24 v of Figure l and showing different positioris 6f the thread feeding and looping mechanism;

Figures 28 to 31, inclusive, are schematic views snewme "the cam a'n'd pin drive mechanism for the -'iieed1e=bar anu feed fodt together with the 'lower portions of the -'iiee'dle=bar and 'fe'ed -foot but and "showing the motions of these parts corr spending "to "the movements of 'the cam;

Figure 32 is a view similar to Figure 2 but showing 'a 'fn'odi-fied form of looping member adapted to memes plurality of threads in each loop;

ing only the lower part of the machihaarid show:- ing 'a'modific'ation thereof-for-handling' pluralities of threadin each loop and which is used with the modified looping member of Figure "32;

Figure 34 is an enlarged front elevation of the ldwerendof the 'needle'of Figure l;

Figure 35 is a side elevation of the lower end of this needle; I "Figure i 6-is a cross section of the needle of Figure'fie t akenon the line 35-36 pf Fig-u-refil;

Figure '37 ;-is an enlarged ;view of a modified stitch control mechanism ;which may be substiue th f F ure- V Figure'38 "is a View of the -rhe'chanism of Figure 37 with a cover plate removed and isa-section taken onthe line 385- 38; of Figure I Figure 39 is a view similarto Figure 38*but with ur he s ri .reihgved; a W Figure 4 0 is a section taken on the line 40- -40 of Figure 38.

Freine's'rmeru'ieEmerita" terminal form's r the operating mechanism in the upper housing "sheet-t0. The eooperatm 'surfaeesjb or which "the follower '2'9'is driven 'by' th g, de gn teu generally 4 or head I is carried on this frame l2 and may be readily removed therewith.

The main drive shaft for the machine comprises a hollow outer shaft [4 and solid inner shaft l5 (Figures 4 and 6) driven by worm I0 through worm wheel I 6. As best shown in Figures 6 and 11, t he worm wheel l6 includes side bearing plates l1 within which is carried a one-way clutch, comprisin a central clutch member l8 and clutch balls or rollers 19 carried in notches formed in the periphery of the member '18; as shown. The

inner surface of the rim of the worm wheel l6 forms a raceway so that, as will he understood, the worm ID will drive the shafts l4--l5 in one direction (clockwise in Figure 11) but not in the other. By this means manual turning of the main fastened to a hollow wheel housing 22 within which and upon which are provided certain arrangements, later to be described, by means of which the aeguiar relationship 'of the enter shaft [4 arid-inner shaft may be variedbr set "as desired within certain limits.

The opposite 'h-d er fiiaihfifilk shaft 14 carne aajacenttne woem'wneei 'lfifa 'i n 73 for 'fli thread looping opefa'tihg iaterueserieeu, and also a drive which, as best shown in Figures 6, 8 an bif reared and throii'gh ep pesed s1 ts 25, '2 6 the =hc11ow h'a ft M, being -fiired' in pos'itfon cooperating rack teeth 21 fof'ihed ontn'e side of the canislot'and a p'i'nilinflfl foi med "-'oi1tlie end of the mixer 'or solfdjslfaft l5, "which-is in iiis'h'iifith tl'fei'ackteeth2 As'will befola'served, tii'rhing 'of the inner ens-rt T5 with reistiontb t-H'e Outer shaft T4 "will, by fiieahs 6f the sack and pinion 21, 28, resiiljt in mov e If ca wise of the main sh ft, For the 'prsenu however, the cam 'ahd shaft will "be siippds'e'd do be in set or fixed relation;

Feed-foot drive in Tneeamfze 'fit's thinaroliowerhead orzyeiie 29fwl1ichisfor'in n thetop'of'fd-foot'pl rig- "er 30 and bears "a drive pin "3| which operates the "needle-bar 3'2 by me'ansor a 'iniitilate d yoke 33 rernrea'atthe top thereo (Figure '1 The rise and fall pardons Yahli Z '"e'a'ch he to raise and lower the feed-foot plungrjih as snow Figure '10, s'pa''d slant penises engaging "opposite portions'iif the can.

The drive pin 3| for the needle-bar is aiigularly r'l'ate'd 13118 Tall 5 p'lfi'fiiti's "(if "171i their 1e 7 position, the rotation of pin 3] earn-esteem this movement "the dwells W and *Df the team will be in contact with the .followerwalls so that the feed-foot bar remains stationary. Continuing movement of the cam-'fl 'brings the parts to the position of Figure 30, the needle-bar having *almo'stcompleted its stroke. At or shortly after thisip'ointtheieed-Toot-commences to rise. Further' rotation continues to move the needle slightly t'downward until the pin 3i "has reached its lowest point.

Rotation through "another '60 will rais the needle-bar and feed-foot simultaneously to the position of Figure '31, and further rotation will 'restorethe partsto the positiono'f Figures land 28 in preparation for another stitch Feed-foot construction and operation 7 By means of the pin-and-slot imountin'g described 'above'the 'feed-"foo't dfl 'is carried by the bar tll both s'lidably and 'pivotally, andthe resu1ting freedom of movement "permits it to find its position with reference to fabric :on the table 62 'and alsowith referenoe'to the needle-bar It? so that substantially the same feeding movement is imparted to fabrics of difierent thicknesses. I

'The'anglefiu df slant'of the feed-foot portion d8 and the angle, V, of slant ofth'es'l'ots 42,'wi11 preferably "be equal as indicated in Fig. 28. In this way, the feed-foot may best accommodate "its'elf tovarying thicknesses of fabri'c whilemaintaining the proper relationship with "the needle- "bar. "'As'will be'understoodfthe presence offabri'c in the machine will altertheposition of the feedfoot "in Figure "29, this member-"coming to rest in "a hig'her position, so that pins 39are notsonear the upper ends of slots 42. However, completion of themovement of the "feed-foot bar 30 will, "through pins39 riding inslots'42, force'theupper end of the feed-foot 40 toward the =nee'dlebar' 32, thus causing the lower end of the feed-foot to move back in the "fabric 'feeding direction. The "fabric "feeding movement will then be completed 'by the needle-bar acting against the slant '88. In 'thisway, substantially the samelengthio'f feed *o'f =the "fabric, regardless "of "thickness, mayb'e obtained. Where, "however, 'theggtldks "o'fthe feedfoot bar30 is "altered, as described below, the

lowermost position -.of pins :39 will be changed and the desired change .in -lengtho'f stitch obtained.

The slight inclination-oi the .fabric table forwardly .adjacent the needle "hole 53, which was referred to above, isdesigned to assist the .action of the feed-foot by furnishing a surface with which "the lower side .of the feed-foot is .in substantial,parallelism whenthe material beingsewn :i-s of zaboutthe maximum thickness vthat themar'chine will accommodate as indicated by the disitanceibetween thgdnclined portionof the fabric table and the -feed f-oot .as seen in l-Figa28 on Fig. 31, and with which the lower side of the .teedfoot approaches substantial parallelism as it :lswings zre'arwardly in a fabric vfeeding direction to:the;position -of:Fig, :30 when the material being sewn'::is :relatively :thin. Inasmuch as the (pins '39 flare-spaced horizontallyfromithesline .of :movement of the needle in the .'construction:illustrated, this :results zan inclination of the :fabric :ta'ble *iorwardly :adjacent rthe :nzgedle. ho'le. -floweever, La construction :in which "the pivotal axis in :feed-Iont is placed "DVBI' the. needle :rhole would require La horizontal isurface f or the "best action of the iced-foot, theimportant characteristic being the substantial parallelism 10f fiche surface with :the :lower side of Lthe fEBdPfOOU'aS-it swings ."to its i'rearward :position about :its ;piv o.tal

axis.

.Thread handling and looping mechanism Threadisiedto the needlebelow thetable B2tby athreadfeeder or looping member 69 and associated mechaniism. :As shown in. Eigure La support [0 having spindles 1 I '-for-a,pair of spool is .provided and, as -indicatedinlFig. i3,athreads iromthe spools are conveniently 'tensioned by Weighted members 1-2 .pivotally carried at 13 onthelower housing walls. .Thedegree of tension provided may belcontrolled .by means of weights 1'4 mountt ed .on .arms 15 which are vpivotally carried upon the members -1.2 at 16, vso that the .distanceaof .a weight 'lltfromthelcorrespondingpivot 13 may be varied, as desired, by turning the arms 1-5.

The looping member 6'9 (Figures v1, '2 and 24) .isiormedat .its upper end withaneedleengagling surface 17, to .eachside .of which are positioned .thread guiding holes I8, and with Wing portions 119 for insuring that the loo-ping member will engag the needle properly. Below this u per 'endthe looping member \69 is pierced as at 80 to permit readystamping and is formed below the piercing 80 with a reversely facing "angular abutmentfl l which cooperates Withzop- -.erating mechanism about to be described. The shank 82 of the member 69 includes :a relatively short portion 83 which is twisted at right'angles, and fastened at .:its lower end :84 :by means of a screw P85 :to a bracket 86 upon the machine base. The shank :of the memberrfiais preferably .flexibility (in its front :and rearward movement, and be relatively estifi :in its sidewise movement,

-due to the fact that twisted portion 83xisshort I relative tothe shankgenerally. 7

Means .for "operating the loopingmember 69 is provided (Figures -1','.3:,and 124 to-27 andcomprises a slidable actuating member 481 formed with-an angle 88 adapted .totengage and receive the :angular iabutment 8.! ,;previously referred duo, and which is carried brackets 8'9 :attached to ea .support-plate flfl, The :supportpplate 9i] includesa portion-9l against which the upper end of the member 69 may slide and-is provided, .toleach side of this portion, with stops 92 :forlimiting movement =of :the :member -69. The respective threads t-A-and :13 pass .from the spools :through the guiding holes 18 of the looping memberrfiil and; as 'indicated in Figures 24 tot-27, movement :of memberl8'l operates the -.thread.:feeding:mech- :sidewise movement will take place-rafter sucheen- :gagement. This {movement brings beth threads :to the left Side of the sneedle. When the .needle :has descended; member --8*1"returns-to center; posiltion', whichipermits member 68,- due to the springmess, of. its shank to return to center position likewise; sothatfthe'fieaijer' 01: righthandthread ma be annuity the needle" against the sem s,

engaging. surface 'IJI Upward movement. of the n'edleivill' new enga e or wipejjthe thread ffib the, hook Where it win" beI heIdby, the, needle until-ithenext'sltitoh."

"I'r fi i cle-Jot o erat ns, he oop previouslv formed Willfbe rlelea liid Q idstartingagain ome; position OfFig'ure'Z lQ the, parts win i e The iiem rv 8.? n l des. an. xte i n 9% g: ure 1;). which is. pivotally on e t d o one e d o a e l c a it t wh ch. in t i c ed by a pivot 95 and ur ed tothe right by a sp v 91i- T the,

o er a m of hell crank 41s votally o ne ed a cam d 9. w i h s; s a lv carr ed y a r ke at 98 formed; he frame mem er i an h c term na es i an abutm nt-Sta d pin H30. xten ns. therefrom. A cam follower- 0; is carried n a pivot Hi2 upon the frame member 12' and com pr ses a foll wer portion I03 and an end "14 whi h en a es. the abutment 9a and which s. p o: ideo with an pen n re v n t ep 1 0.

M chanism for, driving the mem er 8 r u h the, arran emen ,iust des i ed i prov ed, nd is carried on a stubvshaf-t [D5 (Eigures 4= and 5) mounted on the. frame. I as nd ated and wh ch. includes a collar [01 for, retaining it in longitudinal position and a reduced por ion U18. whic passes. through and, supports the. rotatable shaft member I09.

Keyed to the hub of shaft member HEEL are a gear wheel H0 in mesh with the drive pinion 23 previously referred to and a fixedcam member II It WhiCh'iS fastened to the, gear Wheel I I I! as byv means of pins H2 The cam member II-I com prises high Portions H, middle portions M, and low portions L (Figure 12,) forming three, levels for engagement by the cam follower IOI and corresponding. to the threepositions of the. Operating member. 81 previously referred to. The cam as: sembly includes also a pair of adjustable cam members II3 and H4 whichare likewise mounted upon the shaft member um and each of which has a single high level with adjacent rise and fall portions. (Figure, 12.). By adjusting the mem; bers H3 and H4 relative to the member H1 the cam aotioncan be varied as more fully described below. Eorcarrying out this adjustment a pair of arms H5 and I iii are provided, each of which carries a pin, I I! or I I B, which is adapted to enter, into. an opening, H9 or I20, in the. cam member H3 01: H4, as the case may be. An adjusting wheel I.2.I. is keyed to the end of shaft member. I139 and is held on shaft I05 together with the cam assembly by.'means Of a washer I22 and screw I23. As best shown in Eigure 1, the wheel l2l is provided with four peripheral notches or indentation's I24 arid the ends of members H5 and II6. are bent over as indicated so as to provide tongues which are adapted to enter into'thes'e indenta tions and be held thereby.

By turning the members H5 and H6 relative to the Wheel I2'I and fitting. the same in the various notches provided, the contour or the cam may.

bealteredin the following'way: With the parts erations of th I reed-to t f bar e2; bu n nitnira rtd tion, or. th can or from 'a' high lev loivl level. "I

be 8 car ete' r i eh evlel it w t e h ten ai .9- r W setting both members I ls nd lit as in; dic ed'in F siir'e' thecam contour s i i i h W c length va iet es,

M ans is o ed for var i the len th o t qh or the su cessive oop and constitutes a import nt ature of the present invention by mea s o which des rable ooking cha a ter stics re. ob ained, ndby; mea s of Which ve y pleas ris deeo ativ ffects may al o be ob ained a ioulerly. when mplo ed in conjunction with alternation of threads. in the, successive stitches. This means includ a. control mechanism fol".

rotatin the inner or solid 'main drive shaft Movement of arm I25 is controlled withi-re'ierihousing 22 is fixed inrelation to fly wheel 2i 7 and the arm I25 is in turn fixed in its relation to the housing, the shafts I4 and I5 will have at all times a fixed relationship and, accordingly, the relationship of cam 24 to the main drive shaft will be fixed anda fixed length stitch will be pro vided. To permit adjustment of the stitch length in general, a movement of housing22 relative to flywheel 2| is provided for, the latter being furnished with a series of indentations I21 and the housing 22 carrying a member I28 having a corresponding projection I29 which is adapted to enter into the indentations I21. By this means the housing 22 may be turned relative to ill wheel .2I and set'in any of a number of desired. angular positions. Assuming arm I25 to be fixed in relation to the housing 22 this will accomplish the necessary angular adjustment of shafts I2 and I5 for changing the length of stitch.

Mechanism is provided by means of which arm I25 may be fixed in its relation to housin 22 and also for varying its relation to housing 22 so as to produce a sequence of stitches of varying.

length. This mechanism includes, as best shown in Figures 6, 9 and 15 a fixed gear I30 which is formed on the end of the bearin member 20, previously referred to, and cooperating gears I3I' and I32, forminga planetary train, and the latter of which carries a pin I33 which operates in into mesh or out of mesh with the fixed gear I an. by adjusting the arm I35 to the proper one of the two positions indicated in Figures 9 and 15.

Theparts are held in these positions by aprojection I31 upon the arm. I36 which may fit in either of two indentations, I 38 or I39, upon the wall of the housing 22. Movement of the shaft I35 during this adjustment is provided for by a slot I40 in the wall of the housing member 22 and rotation of the gears I3I and I32 when in the position of Figure 9 is prevented by a'pin I4I which is carried by the housing 22, as shown.

As will be apparent, with the parts in the position of Figure 9 the relationship of slotted arm I25 to housing 22 is fixed due to the fact that pin.

I33, which engages in its slot, is fixed in position through the teeth of gear I32 in mesh with gear I? I which in turn is held from turning by the pin I4I. If, however, arm I36 is turned so as tobrin gear I3I in mesh with fixed gear'I3fl,

the'position of arm I 25 with relation to the housing 22 will no longer be fixed but the arm I25 will be rocked back and forth by pin I33 as the gears rotate. In the construction shown, gear I 3| has al to 1 drive ratio with the fixed gear I35 and hence will make one complete rotation for each complete rotation of the main drive shaft and housing 22. The gear I3I has, however, al to 2 drive ratio with the gear I 32, which accordingly will make a half rotation for each rotation of the main drive shaft and housing 22. It should be noted, in this connection that the position of the gear I 32relative to the rotating shaft I5 rather than to a statlonary'part is the determiningv factor in-the production of the rocking movement. Accordingly, a complete rQ-- that stitches are taken alternatively from the tation of the main drive shaft and housing 22 cordingly. A second complete ,rotation of the main drive shaft'and housing 22 will restorethe parts to the previous position of Fi 15. When it is borne in mind that rockin of shaft I5. relative'to shaft I lmoves the cam 2450 as to. vary the stitch length, it will be apparent that the stitch length on the even numbered rotations of the housingwill be increased from that which occurs when the arm I25is in the. position of Figure 9 relative to the housing.22. .In this way, the stitch of Figure '22 may be formed, the thread feeding cam having been set as in Figure 10 so two threads. By setting the member :IZB for a short stitch and the arm I36 for stitche of vary ing lengths,. and assuming the parts to be inthe position of Fig. 15, the machine will produce at turn to their original position the next'loop'will' be a short loop formed from the first thread and in this way a succession of alternate short and long loops formed from the respective two threads 7 will be obtained. Wide variation in the varied length stitches is obtained by adjusting for a desired eccentricity of the drive member and then rocking the inner shaft I5 to vary thi'sjeccentricity between predetermined limits. 7 If desired, the thread feeding cam may be set as shown in Figure 14 and in this case a stitch such as shown in Figure 23' will be produced, consisting of a single chain stitch having its alternate loops of different lengths. i 1 a 7 Setting the thread feeding cam to the, position of Figure 13 will resultin a composite stitch in" which the alternate loops are long and short and in which three loop are taken successively fromone thread and one from the other. As is apparent, this setting will result, for example," in V a short White loop followed, by two long white loops and then by a lon colored loop and again by a short white loop and so' on; Alternatively, a long white loop followed by a short white loop, a long white loop and a long colored loop may be obtained. These stitches, the formation of which will be evident from Figures 22 and '23, are not illustrated. 1

The formation of feed-foot drive cam 24 co stitutes an important feature of the present invention andinvolves provision for maintaining a sufiiciently constant advance of'the feed foot movement with relation to the needle-bar movement while varying the stitch length which depends upon the feed-foot movement) and the loop length (which depends upon the needle-bar movement) simultaneously so as to increaseor decrease the stitch length and loop length in substantially the same proportion. I

Aswill be apparent to those skilled in the art, those machines in which the tension mechanism. permits stitch length variation by'merely varying the fabric feed will not require any-variation.

in stroke of the needle-bar to produce the varied length stitches. Alternatively, machines havine tension regulation suitable therefor may be adapted to produce the varying length stitches by varying only the stroke of the needle-bar. In view of this, the simultaneous regulation of fabric feed and needle stroke, while preferred, is" not essential to the practice of the invention in its broader aspect.

As will be observed, when the shafts I4 and I5 areadjusted so as to increase the eccentricity of the cam 2'4 (by moving the same upwardly when in the position of Figure the distance of pin 31 from the center of rotation is increased substantially proportionately. On the other hand, the angle of advance of the cam high dwell ahead of the pin 31 is diminished only slightly and any effect thereof upon operation of the machine will be negligible. In this way, the fabric feed is automatically adjusted, by controlling the height of the feed-foot carrying pins 39 at the end of the down-stroke of the feed-foot bar, so as to increase or decrease the fabric feed proportionately, while the proper advance of the feed-foot movements over the needle-bar movements is maintained. In the construction shown, suitable stroke variation is also imparted to the needle-bar.

The improved locking characteristic of the varying length stitch produced by the described mechanism will be apparentfrom Figures 22 and 23. In either case when it is attempted to separate plies of fabric which have been stitched together, a short loop (white loop in Figure 22) will be pulled through the fabric until its bend or tip is about to pass through. It is however, impossible for this to occur without the loop being freed of the long loop which passes through it, and this longer loop will lie across the fabric preventing the short loop from passing through in much the same fashion as would a pin, if passed through the short loop. This effect is, of course, not obtained with a chain stitch having loops of equal length as the loops are able progressively to free each other by successively falling back. While the best locking effect will be obtained b alternating the short and long loops, and by making the short loops as short as possible and the long loops as long as possible for a given average length of stitch, this is not essential for practicing the invention in its broader aspect, as sufiicient locking effect for many applications may be obtained by using shorter and longer loops of various lengths in various sequences.

Construction of feed-foot drive, cam

The cam 24 may be regarded as a modified eccentric having dwells during which substantially no movement of the follower is produced. As will be apparent, this is only substantially true, but may be made sufficiently true so that the desired operation is not interfered with.

The cam comprises opposite high and low arcs W and K (Figure 28) each of which occupies approximately a third of the circumference, or about 120, and which are connected by respective rise and fall arcs Y and Z each of which in turn occupies approximately one sixth of the circumference, or about 60. The arc W may be developed as a dwell concentric about an arbitrary center and the arc X will have its points equidistant from this are when measured along diameters through the arbitrary center. This insures, during the rotation of the cam with its high and low dwells in contact with the straight sides of the follower slot, that relatively close engagement without undesired play may be obtained. The rise and fall portions Y and Z are symmetrical about a line through the centers of the dwells and are determined so as to maintain the same distance between points which are opposite with relation to the arbitrary center referred to. In thiswa'y, close engagement 'of'the cam with the follower at all angular positions is provided for.

As will now be apparent, the dwells cannot be precisely con-centric about the center of rotation of the cam when the cam is in its various positions which are provided for adjusting the stitch length in general or for producing alternate stitches of different lengths. It is found, however, that adjustment of the cam through the small distance which is necessary to give a relatively wide variation of stitch lengths will not disturb concentricity of the dwells sufficiently to be objectionably perceptible in the action of the machine. The drive pin 3| for the needle bar yoke is set upon the cam 24, as previously indicated, so as to interrelate the cycles of operations of the feed-foot plunger and needle-bar in the desired way. In the type of construction illustrated, this may involve setting of the pin approximately behind the commencement of the high dwell of the cam. The incline of the straight sides of the cam follower slot is provided for the purpose of properly correlating the needle-bar and feed-foot movements. The pinand-yoke drive used for the needle-bar requires that the drive in 31 operate in a dwell during approximately the upper third of its rotation. The. advance of cam 24 with relation thereto must however be set within certain angular limits in order to provide for the adjustment referred to above. When this has been done, an inclined follower surface will be found necessary, as the feed-foot bar movements produced by a horizontal yoke would not be sufliciently early with relation to the needle-bar movements.

The cutting out of a portion of the low dwell X of the cam to form the adjusting slot therein has been found not to result in any appreciably objectionable play. In this connection it should be observed that the high dwell drives the follower in both directions.

Recapitulating the operation of the feed-foot cam and cam follower and the needle-bar pin and yoke, respectively, it will be observed that the cam produces a downward movement of the feedfoot through about one sixth of the revolution, followed by a dwell through about a third of the revolution, by an upward 'movement through about a sixth of the revolution, and by another dwell in raised position through the remaining third of, the revolution. This cycle therefore cone tains four phases. The needle driving pin, hcwever, has only three phases oioperation, having a dwell through about a third of a revolution, a downward movement through another third, and an upward movement through the remaining third.

As suggested above, the division of rotary movements into sixths and thirds is not exact and need not be so, but a discussion in round figures of the relation of the two movements and omitting small angular variations will serve to simplify the same. Recalling the lead of the cam high dwell as compared with the drive. pin, and starting in the position of Figures 1 and 28, a complete cycle of movement maybe analysedin successive steps of one-sixth of a revolution, as set forth in the following table:

Feed-Foot Bar ctlon N eedle-B ar Action Moves down to Stationary.

position of Fig. 29

First sixth Moves down, pushing feed-foot to position of Fig. 30, just before entering fabric, hook of needle opens due to T-head Second sixth Stationary Needle construction merely coming down on top of the point of the,

hook, is formed with a groove I50 adjacent its lower end and adapted to receive the barb or point I5I of the needle. The point of the needle is accordingly'set back toward the central axis of the needle so as to be about one quarter of the general needle diameter therefrom. As shown in I Figure 35, the hook of the needle is sufficiently recessed to provide a space I52 for receiving the 7 thread, which may be secured or locked therein by the pin.

Modification of looping member to handle pluralities of threads According to another form of the invention, each loop may be formed with a plurality of threads from separate spools. In this case the thread looping member 69 may be modified as indicated in Figure 32, in which corresponding parts are indicated by numerals similar to those of Figure 2, but increased by 100, so as to have two thread holes or guides I18 at each side of the needle engaging portion III instead of a single thread guide 18 as in the case of the embodiment of Figure 2. As shown in Figure 33 which reproduces a portion of Figure 3 and shows modifications therein, a second spool supporting member I I8 and further tension members I'I2, etc., may be provided so as to furnish a thread A1 in addition to the thread A. The thread A may go through a lower hole' I18 and the thread A1 through the'one immediately above it. As will be understood; similar spools furnishthreads B and 131 for the holes I18 on the opposite side of the thread engaging surface I".

With this construction very novel decorative effects may be obtained, one loop being formedfor example of a red thread and a blue thread and the next of a yellow thread and a purple thread. Many other combinations will be apparent, and it should be noted that with this arrangement, as compared with possible alternatives, the position of the threads both in the loops andin the courses on the reverse'side of the fabric will be the same 7 from loop to loop so that very pleasing and uni form effects may be obtained. I

Modified drive for the thread handling mechanism Greater variation in, or control of the orderof, production of stitches from the threads than is provided for in the construction as heretofore described may be obtained by suitable modification of the operating mechanism.

One such modification, involving the substitu tion of other mechanism for the cam I I I, is illustrated in Figures 37 to 40. Figure 40 is a view similar to Figure 5 but on an enlarged scale and showing modifications. As there shown, a shaft member 296, similar to the member I05 of Figure 5, is provided and carries a rotatable hollow shaft 299 generally similarto the shaft member I09 of Figure 5. A gear wheel 210 is provided for engagement with the drive pinion 23 and is similar to thegear wheel III] except for modifications about to be described.

The operating structure carriedon the hollow shaft member 239 comprises an inner disk 2| I, secured to the gear wheel 2H! as by means of pins 2I2 and keyed to the hollow shaft 269, and also a cog shaped member 2I3, which is keyed to the hollow shaft 209, and provides surfaces Mi serving as middle levels for engagement by a follower member 20I which is mounted on a pivot 202 and controls the movements of th rod 91 previously referred to. Four additional members 2 I4 are provided and each is adapted to be adjusted so as to serve as either a high level or a low level for engagement by the follower member ZIII. Each such member comprises a short inner shaft 2I5, an eccentrically disposed intermediate portion 2 I I5 and a reduced outer shaft ZI'I. The inner shafts 2 I 5 pass through keyhole openings 2 I8 in the disk 2! I and through circular openings 2 I9 in the gear wheel 2 I ll which latter openings serve as bearings. The reduced outer shafts 2 I I in turn are carried in openings 229 in a face plate 22I which is keyed to the hollow shaft 289. Each member 2 I4 is urged,

axially of shaft 209, toward the position of Figure 4.0 by a spring 222 thrusting against disk face plate HI and carries an adjustment knob 223 poi sitioned outside of the face plate 22 I.

Each cutout H8 in the disk 2II is shaped so as to receive the operative portion 2I6 of a member 2I4 and hold the same in an outward position (to right and left of Figure 38) orin an inner position (upper and lower positions of Figure 38 and position shown in Figure 40). The construc tion of the disk 2| I is shown more clearly in Figure 39, which is similar to Figure 38 but in which the members 2 I4 and 2I3 have been removed. By pulling out the knob 223 so as to release the member 2M from engagement in an opening 2I8, the

member may be turned so as to present either a high or a low level to the follower and then allowed to return so as to seat in the opening 2 !8 and be held in the desired position. The contour of the high levels H1 is not critical as it is immaterial whether there is actually a dwell in the follower mov ment or not and the same is true of the low levels L1;

The cam follower 20I maybe constructed with a bearing surface E conforming to the tip radius of the member 2 I3 so as to produce a dwell in middle position. The length of dwell, expressed angu larly, will equal the angle subtended by the middle level M1 added to twice the angle subtended by the follower engaging surface E. To each side of the 17. engaging su-r'face E the follower member is-formed' with rise'and fallsurfacesvRiand F;

The structure just described provides forsue cessive sequences of either'high or loW' levels as desired and will produce the same operation aswill structure of Figure 5previous1y described: However, the structure of Figure 5 will provide: only for adjustment to -give four high:leve1s,- three high levels, or two'high levels while the present structure will providein'addition'for only one high levelor'for no high levels: Hencewhilethe con struction. ofFig'ure 5 may produce only the stitch:

sequences AAAA'; ABA'BK-from two threads identified as A- and B) the constructio'n' just de: scribed will produce in: addition the' sequences ABBB and-BEBE; In addition; the 'modified con struction will provide for the sequence AABB;-- which is not possible with the cons'tr-uction of Figure 5.

What is claimed is:

1. In a chain stitchvsewingi. machine, and incombination; a hooked needle; a reciprocable needle-banmeans. for reciprocating said needlebar,v thread handling mechanism cooperating. with said needle for forming a loop-at each-re ciprocation thereof, fabric feeding mechanism for feeding fabric past saidv n'e'edl'e' ateach reciprocation thereof", and automatic means for varying the length ofstroke ofsaid needle-bar at the successive reciprocations thereof to vary the length: of loop;

2. Ina chain stitch-sewing machine; and in combination; ahooked" needle,- a='- reciproc'ab-le needle-bar, means-ifor reciprocating saidlne'edle bar, thread handling :mechanism; cooperating; with" said needle for formingua loop at each re ciprocation thereof, fabriofeeding mechanismfor feeding fabric past said-needle at each: reciprocationthereof, and automatic means forvaryingthe length-of stroke of said needl'e bar from a longer stroke to a shorter stroke in a-pre= determined sequence at the successive recipr0- cations thereto toproduce-longer and: shorter loops in apredetermined sequence.

3. -A- sewing; machine according to claim: 2, comprising.- also manuall adjustable-stroke reg-u lating means for: regulatingthe lengths of I said. longer Eiild ShOT'tBfSbtOkESi" 4-.- In a-chainstitchsewingipmachine; and in combination, a 'recipr'oeable"needle-bar and afeed-foot, operating'mechanismfor; reciprocating: said needle-bar and movingsaid' feedoot, com prising; automatic ni'ear'isforvarying the: length of the suocessive strok'es' of said: needle-bar and operative movements of said feeds'foot -in a predetermined sequencei i 5; In achain stitch'sewing.=machine, and in combination, a reciprocableneedle bar; a feed foot; and operating mechanism forreciprocating. said needle bar and: imparting :an' operative movement tosaidfeed-foot at each reciprocation of said needle bar, thes'aid operating mechanismcomprisingrvautomatic: meansfor producing tnee-" die-bar reciprocations: andl-ccorrespondingr feed-' foot operative movementswof twozdifierent lengths' in aJpredeterminedsequen'ce;

61A: seWlng='-:machine' according to -claim 5, comprisingalso: manually adjustabl means-"for regulating the two said xdifferent lengths 7. In achain stitch sewing. machine, and -in combination, a recipr-ocable needle bar; a feed foot;v afeed-foot operatingi member, an eccentric 18 st'it'ch regulating means: for varying the eccentridity'ofsaid drive memberwith relati'on td th axis of said drive shaif-twhile-maintaining a substant'ially fixed relationshipbetween the movements of said needle-bar andopratihgmember relative-*to the angular position of said drive shaft. Y

sewing-machine according to claim '7, in whicl i the said stitch regulating means comprises automatic niean's forvarying the eccentricity of said "drive member to produce apredetermined sequence ot stitches ofvarying length 9'. Id a-chain stitch sewing machine, and in com atiOn -a--rec'-iprccable needle-bar, afeedio'ot, a feed 'foe't operatingm'ember; an eccentric drive member-inoperative relationto both said needle-bar an'd ;-feed -foot operating member, a driveshaft carrying said drive member, and stroke: regulating means for varying the ccentrici-ty" of said drive member comprising means for moving-said drivememher'transversely and reetiimeariy upon said drive shafti 11)? A sewingmachine-according to claim 9, in whicl-i thesaid." strokeregulating means comprises automatic i means for varying the eccentricity ofsaid drive member-- to produce corre spondingly-varyiiig movementsof said needle-bar and saidf ed foot-operating member" in a'predetermined-sequence;

manuallyadju'stablemeans for setting'said drive member" various adjusted positions upon said shaft and-automatic means for moving said drive em'eniloers h'etween predetermined limits with refpi-nio'riiri" mesh with" saidfra'ck; and stroke regulatirr means for Va'ryingthe' angular position of said inne fishaft withlrelationto 'said'hollow shaft tovarythe'eccentricityof saiddrive member with relatiomto *saidhollbwshetft.

7 sewing m'achine accor'ding toclaim '12j in which-the said stroke regulatingmeans comprises a fixed gear concentric with said hollowi shaft and a planetary gear train in" mesh with" said a needle-bar, a feed-foot bar, a fabric table; meansfor" reciprocating said needle-bar" and feed-foot drive member in operative relation 'to both said:

needie-bar"and lfeed footoperating member,- a I drive haft icarr-ying -iz said: drive member; and

barto and away from saidf'a-bric table; a feedfoot; and m'eans mounting-"said -feedfoot 'slidably' along and pivota'lly upo'n saidfee'd foot-bar in the ment therehyg wherebysaidfeed-footis-positioned witli reference to 'said fahric table in accordance witli' tlie tlii'clinessof fabric thereon and-is forced asid'e h 'saidneedle-bar to impart affeedingmovementtd fabric upon said fabric table. I l

15. A sewing machine according--toclaini 14} in which the- Said means l'hbllritin'g "t'he feed-robe 11.1 e ewin machine according t o claim 9; ini which the said-stroke"regulating means comprises 19' uponthe feed-foot bar comprises a pin-and-slot connection slanting upwardly toward said needle bar, and the feed-foot comprises a portion engaged by said needle-bar and slanting downwardly toward said needle-bar. j

16. In a sewing machine, and in combination, a reciprocable needle, a fabric table cooperating therewith, feeding means for moving fabric along said table, a fabric-foot for holding fabric against said fabric table, a support member inclined downwardly and forwardly toward said fabric table, means for slidably mounting said fabricfoot on said support for movement downwardly and forwardly against *the direction of fabric movement, and yieldablemeans for urging said fabric-foot toward said fabric table.

17.'l'.n a chain stitch sewing machine, and in combination, areciprocalble hooked needle, thread handling mechanism cooperating therewith to form a succession of loops and comprising thread holding means positionable to present any of a plurality of different threads to said needle for engagement thereby, at each reciprocation thereof, drive means for positioning said thread holding means, and means for adjusting said drive means topresent the said different threads to said needle in any of aplurality of diiferent sequences.

'18. In a chain stitch sewing machine, and in combination, a reciprocable hooked needle, thread handling mechanism cooperating therewith to form a succession of loops and comprising means positionableito present any of a plurality of different threads to said needle for engagement thereby at each reciprocation thereof, and drive means for positioning said thread holding means comprising a cam having adjustable levels and means for. adjusting the levels of said cam to present the said different threads to said needle in any of a plurality of predetermined sequences.

19. In a chain stitch sewing machine, a hooked needle, thread handling mechanism cooperating therewith and comprising a looping member having a'central bearing surface for engaging said needleand lateral thread guide portions on opposite sides of said surfacefyieldable means for urging said member toward engagement with said needle'and pressing said bearing surface against said needle, and machine drive means for moving said member away from said needle into either of two positions onopposite sides of said needle and" lying on a line spaced from said needle, so

as to bring both said thread guide portions on the samesideof said needle when said member is in releasing said member to permit said yieldable which the same machine drive means comprises adjustable means for successively and selectively moving the said member into the said two positions in any of a plurality of predetermined sequences. I

21; In a chain stitch sewing machine, a hooked needle, thread handling mechanism cooperating therewith and comprising a, looping member havinga central bearing surface for engaging said needle and lateral thread guide portions on opposite sides of said surface, relatively flexible spring means for urging said member toward engagement with; said needle and relatively stiff spring means for centralizing saidmember with relation to said needle, and means for moving said memberaway from said needle into either of two positions on opposite sides of said needle and lying on a line spaced from said needle so as to, bring both said threadguide'portions on, thesame side of said needle when said member is, ineither of the two said positions, and-means for releas-. 7 ing said member to permit said yieldable means.

to: return the same into position engaging said needle.

22. In a chain stitch'sewing machine, a hooked needle, thread handlingmechanism cooperating therewith and comprising a looping member hav ing a central bearing surface for engaging said needle and lateral thread guide portions on opposite sides of said surface, .a'flexible strap spring for supporting said member and comprising a rel-;

of the two said positions, andmeans for releasing said member to permit said yieldable means to re;

turn the same into position engaging said needle.

23. In combination in a sewing machine, a thread supply source, a needle having a hook near an end thereof and a guideway extending longitudinally of said needle from said hook toward the other end of said needle, a member having at one end a channel adapted to receive the barb of said hook, said member being slidably arranged in said guidewayand reciprocable to and from a position at which said channel surrounds the barb of said hook and formin'gwith said hook a closable thread receiving opening, means for moving said needle to and'from, operativerelationship with said thread supply source, and means fo'r operating said member to close said hook. asit moves away from operative relationship with said thread supply source and to open said hook as it moves toward said thread supply source. 24. In combination in a chain stitch sewing machine, means for forming from thread a-succession of loops, said means including a movable means successively engageable with said thread to form loops therefrom and, during each succeeding loop-forming movement,passing through the next preceding loop to thereby provide interengaged loops forming aseries of chain stitches,-

and, means controlling said -movable means for sequentially varying the effective length of move ment thereof to correspondingly sequentially vary v the length -of said loops. r V

25. In combination in a chainstitch sewing machine, means forforming from threads a succession of loops, said means including movable means selectively engageable with said threads to form certain-of said loops of at least one of.

said threads and to form certain other'said loops of at leastoneother of said threads'and, during each succeedingloop-forming movement, passing through the-next preceding loop to thereby pro-. 'vide' interengaged, loops formingv a' series of stitches, and means sequentially controlling-said movable meansfor varying. the effective length of movementthereof to correspondingly sequena tially varythel'engthof said'loops. V

26, -In combination in a. chain stitch sewing machine, means. for forming from thread a suc- I cession ;of loops, said means including. movable means engageablewith said thread toform loops therefrom and, during .each. succeeding loopforming movement, passing through the next pres:

ceding loop to thereby provide interengaged loops forming a series of stitches, means controlling said movable means for sequentially varying the effective length of movement thereof to correspondingly sequentially vary the length of said loops, and other means controlling said movable means for predetermining the effective length of movement thereof during the formation of each of said loops to thereby determine the length of each of said loops.

27. In combination in a chain stitch sewing machine, means for forming from thread a succession of loops, said means including movable means engageable with said thread to form loops therefrom and, during each succeeding loopforming movement, passing through the next preceding loop to thereby provide interengaged loops forming a series of stitches, means controlling said movable means for varying in any of a plurality of sequences the effective length of movement of said movable means to correspondingly vary the length of said loops, and means for selectively setting the controlling means so that the effective length of movement of said movable means and the loops formed thereby correspond to a selected loop-length sequence.

28. In combination in a chain stitch sewing machine, means for forming from thread a succession of loops, said means including movable means engageable with said thread to form loops therefrom and, during each succeeding loopforming movement, passing through the next preceding loop to thereby provide interengaged loops forming a series of stitches, and stitchlength determining means for producing relative movements between the machine and a fabric being stitched, and means controlling said stitch length determining means for varying the length of relative movements between said machine and fabric in a predetermined sequence and simultaneously controlling said movable means for varying the effective length of movement thereof to correspondingly vary the length of said loops so that the length of the loop for each stitch is substantially equal to the sum of the relative movement between said machine and fabric and the thickness of the fabric.

29. In combination in a chain stitch sewing machine, means for forming from threads a succession of loops, said mean including movable means selectively engageable with said threads to form certain of said loops of at least one of said threads and certain other of said loops of at least one other of said threads and, during each succeeding loop-forming movement, passing through the next preceding loop to thereby provide interengaged loops forming a series of stitches, and means selectively controlling said movable means for varying in each of a plurality of sequences the effective length of movement of said movable means to correspondingly vary the length of said loop in loop-length sequences respectively corresponding to the first said sequences.

30. In combination in a. chain stitch sewing 22 machine, means for forming from threads a succession of loops, said means including movable means engageable with a plurality of said threads to form a series of multi-thread loops therefrom and, during each succeeding loopforming movement, passing through the next preceding multi-thread loop to thereby provide interengaged multi-thread loops forming a series of stitches, and means selectively controlling said movable means for varying the effective length of movement thereof to correspondingly vary the length of said multi-thread loops in a plurality of sequences of loop lengths.

31. In combination in a chain stitch sewing machine, means for forming from threads a succession of loops in a plurality of thread sequences and in a plurality of loop length sequences, said means including movable means selectively engageable with said threads to form certain of said loops of at least one of said threads and certain others of said loops of at least one other of said threads, and, during each succeeding loop-forming movement, passing through the next preceding loop to thereby provide interengaged loops forming a series of stitches, means for selectively controlling the first said means to cause engagement of said movable means with a predetermined number of said threads in any of said plurality of thread sequences, and control means for selectively varying the effective length of movement of said movable means to correspondingly vary the length of said loops in any of said plurality of loop-length sequences.

32. In combination in a chain stitch sewing machine, means for forming from threads a succession of loops, said means including movable means engageable with said threads to form loops therefrom and during each succeeding loopforming movement, passing through the next preceding loop to thereby provide interengaged loops forming a series of stitches, and means for selectively engaging with said movable means each of a plurality of said threads in a predetermined thread sequence, and control means for sequentially varying the effective length of movement of said movable means to correspondingly sequentially vary the length of said loops.

THOMAS E. MONROE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 29,268 Hicks July 24, 1860 2,042,590 Chiti June 2, 1936 2,206,484 Monroe July 2, 1940 2,288,051 Voigt June 30, 1942 1,017,164 Noble Feb. 13, 1912 FOREIGN PATENTS Number Country Date 427,803 France Aug. 14, 1911

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