US2825296A - Stop-motion mechanisms for sewing machines - Google Patents

Description

R. D. SWEET ET AL STOP-MOTION MECHANISMS FOR SEWING MACHINES March 4, 1958 3 Sheets-Sheet 1 Filed March 1, 1954 March 4, 1958 R. D. SWEET ET A1.

STOP-MOTION MECHANISMS FOR SEWING MACHINES 3 Sheets-Sheet 2 Filed Marjoh 1, 1954 lm/ENTOR. Ray D; Swee and BY Will/'am d. Edwards WITNESS March 4,l 1958 R. D. swEET ET AL STOP-MOTION MECHANISMS FOR SEWING MACHINES Filed March l, 1954 3 Sheets-Sheet 5 :Nm/'roza Ray D Swee and BY Will/'amd Edwards WITNESS ATToRm United States Patent 'G STOP-MOTION 'MECHANISMS FOR SEWING MACHINES Ray D'. Sweet, Bridgeport, and William J'. Edwards,

Stratford, Conn., assignors to The Singer Manufacturing Company, ElizabethyN. J., `a corporation of New' ersey `Application March 1,\1954, Serial No. 413,228 Claims. (Cl. 112219) Thelpresent `invention relates to sewing machines and has for aY primary object to provide .anew andimproved stop-motion mechanism Yfor sewing machines.

Morelparticularly, itis an object of the present invention to provide' combined driving and stop-motionfmechanisms for sewing machines similar to that disclosed and claimed in the tro-pending application of lvanko,Serial No. 385,097, tiled October 9, 1953, now.v Patent No. 2,721,526, October 2'5, 1955, whichrmechanisms arei provided with improved actuating means.

In addition, it is an object of this invention to provide, ina tacking machine having a stopmotion mechanism automatically actuated uponcompletion of? the tack for bringing the machine to a stop, means for varying the number of stitches-inthe tack. f Specifically, itl is-an object-lof this invention to provide means in such alma chine yfor'bringing the stop-motionV mechanism into operation' after only a fraction of theA predeterminedtack has been made'or atan intermediate pointain'the designed tackingcycle and aganat the endof the designed Vtacking cycle, thuslproducing two tacks each consistingof a fraction of the originallydesigned tack.

Having in mindv the above and other objects that4` will be evident from an understandingof this disclosure, a presently preferred embodiment of the invention is hereinafter set forth in such detail as to enable those skilled in thea'rt readily to understand thefunction, operation, construction and advantages of it when read 'in conjunction with the accompanying-drawings, in which:

Fig. 1 is anelevation view of a sewing machine'embodying the present invention, the cover-plate of .the frame being removed and portion of the bed broken away and shown in section better to illustrate the invention.

Fig. 2 is'a section view taken substantially on the line '2 2r of' Fig. 1.

Fig. 3 is a fragmentary section view' taken substantially on theline 3-3 of Fig. 2. l

Fig. 4 isa view similar to Fig. 3 but showing theelements in a dilerent operative position.

Fig. 5 is a'fragmentary section view taken substantially on the line 5*-5 of Fig. 1.

Fig. 6 is a fragmentary view inA elevation' of a detail 'of the mechanism as illustrated in Fig. 5'.

ythe bed. 1. The-base 5 is provided with resilient feet 9 which are adapted ito' support the samek upon `any'su'itable supportingisuface, such as a sewingmachineitable.

J'rnale'd 'longitudinally of' vthe kbed 1 is' av main-shaft 2,825,296 Etented Mar. 4, 1958 or bed-shaft 10 which extends'through they side-wallof the-machinebed and hassecured upon'fthe external en'd journaled longitudinally of the-army 3; Thelarm-'shaft 17 is oscillatedby .means of a .crank-'arm 18 -securedito the Shaft andvhavingv theend thereof pivotedfto the upper end vota 'connecting-:rod 41'9 .arranged vertically in` the standar'dZ and connected at its lower end to a crank-20 formed. on thesbed-shaft` 10. The needle-bar' 12-isvv so mounted ,as tolbe y,capablegot movement laterally of 4`th'e arm 16 oli .the .fbedcL and lateral vibration is-imparted thereto by a lever21 .pivoted 12o-the` rframerbyan Aadjustablepivot 22,.,andoscillated.by-means of af cam vvgroove (not shown) -ina cams23. :The-cam 23 istsecured toa cam-shaft 24.journaled verticallyainfthecstandard- 2,;to which cam-shaft is secured aesecond cam .25. Rotation is-imparted to the-cam-shaft 24 by afgeai-WZG lixedvthereto and meshing with ap Worm: (not shown) -"on.the'rotary bed-shaft` 10. Means are -provided 'for "vibrating vthe looper 142in timed relationrwith'y the vibration of* the needle to maintain proper stitch-forming.'relationbetween them,F which-means, while not illustrated rherein in-detail since suchconst-ructions are old and well known, may be actuated by acam Yfo1lower27carried'byanarm 28, which follower cooperates with acamagroove29 (Fig. v5) in the upper face of the camlS.

ln the illustrated machine thereais provi-ded a buttonclamp 30 having the usual button-clampingja-ws 3l, which button clamp-is pivotally mounted bymeans'ofahorizontally arranged pivotl pin32 to aV frame y33 fslidable longitudinally ofthe bed 1. As iscustomary intbutton-sewing machines adapted to sewfour-hole buttons; thene'edle is' vibratedV laterally v of the. work-supporting'iarm between two .of the Yholes inthe button until.theadesiredfnumb'er ot' stitches therethrough ,havebeen made. The@ clamp is then Shiftedlongitudinally of the arm and` thevneedle-is vibrated laterally of the arm betweenrtheYother-two'holes in the button.- .To shift .the frame 33` longitudinallyfof the arm 16 there .isprovidedi'a shaft 34 (Fig. 5)- journaled vertically. in the bed 1v andfoscillated-by-.means of a crank-arm 35`xed to the. lower end thereof-and carrying atits .outer end a follower that cooperates withlafcam groove (@notshown) in the upper vface of theicamf 25. At its upper end the shaft 34 isoperatively jconnected to the frame 33 for reciprocating the frame longitudinally ofthe work-supportingv arm uponoscillation of-.the shaft, which connections are notherein., described infdetailzsince theyform no part of the preSentinVentiOn- HThe buttonclamp 30 is--resiliently urged: aboutitspivot 32toward vthe slide-plate 36k forming a part of theframe 33. by a presser mechanism that includes a hollow presser-bar 37 that engages the button-clamp 30 at its-lower endand is slidably` mounted at vits upper end in a bushing 38 carried by the .bracket-arm 3. The presser-bar 37 is urged downwardlyby a spring39 itted into the hollow bore oflth'e presserbar and abutting'atits lower end with the bottom thereof and'at its upper end'against the' endlot" anadjustin'g screw 40 threadedv into thelbushing" 38. The vbutton-clamp 30"'may vbe raised and lowered by alongimessage 3 tudinally adjustable link 41 connected at its lower end to the buttonclamp and at its upper end to the end of a crank-arm `42 fixed to a clamp-lifter shaft 43 journaled longitudinally of the standard 3 parallel to the arm-shaft 17. The shaft 43 is oscillated by a rod 44 mounted ver-l tically in the `standard 2 for vertical sliding movement and connected at its upperend by a connecting link 45 to the :end of a crank-arm 46 secured to the shaft 43. The rod 44 is urged downwardly, which is the direction i in which the button-clamp 30 will be lowered, by a spring 47.y The rod 44 may be raised to open the button-clamp 30 by exerting a pull on a chain 48, as by a conventional foot-treadle, which chain48 extendsthrough an aperture 49 in the base 5 (Fig. 5) and is connected to onc'arm chain 48, the bell-crank lever is pivoted to lift the rod 44 which in turn oscillates theshaft`43 and lifts the buttonclamo `30. i i

The driving and stop-motion mechanisms of the disclosed machine include a two-part separable pulley 11, as hcreinbefore mentioned,I about which pulley is entrained a driving belt 55 that is adapted to be operatively associated with any suitable source of power. The pulley 1l consists of a fast pulley element 56 and a loose pulley element 57. The inner or fast pulley element 56 consists ofa `web Ior ange 58 having an annular surface 59 forming a first belt-groove face and formed unon the outer face of the flange 58 adiacent the outer edge thereof. The flange 58 is integral with a sleeve 60 keved to the shaft by a pair of kevs 61 and held against sliding movement lengthwise of the shaft in one direction by a split ring 62 tted into a groove 63 in the shaft and n the other direction by a bushing 64. The outer or loose pullev element 57 consists of a web or flange 65 having a cylindrical surface 66 and an annular surface 67 which form the bottom wall and second side face respectively for the belt-groove.` A sleeve 68 is formed integral with theange 65 and a soft metal bearing sleeve 69 1s press fitted therein. The bearing sleeve 69 is mounted on the shaft 10 for rotation and sliding relative thereto. The sliding movement of the loose pulley element longitudinally of the shaft 10 is limited by a split ring 70 fitted 1n a groove171 formed in the end `of the shaft 10. A cap 72 is fitted over `the end of the shaft 10 and formed to engage the sleeve 68 of the loose pulley element 57 and to be frictionally `held thereon. The cap 72 carries an anti-friction ball 73 that is adapted to be engaged by a spring arm 74 which,as hereinafter more fully explained, serves to slide the loose pulley Velement 57 toward the fast pulley element 56.` When pressure is exerted on the antifriction ball 73 by thespring arm 74, the loose pulley element is forced into operative `relation with the fast` pulley element, as illustrated in Fig. 4, in which relation the belt 55 is clampedbetween the belt- groove faces 59 and 61. Thus, the belt`55 is frictionally held against slipping relative to the :fast pulley element 59 and will thereby drive the machine. When the pressure on the ball 73 by the spring arm 74 is relaxed, the loose pulley element is free to move axially away from the fast pulley element thereby separating the belt-groove faces 59 and 67.` The split ring 70 is positioned on the shaft 30 so that the loose-pulley element 57 can move away from the fast pulley a distance great enough to space the belt-` groove faces 59 and 67 apart a distance greater than the width ofthe belt 55. There is provided a belt-shifter 75 (Fig. l) carried by a bracketA 76 secured to the frame and including an arm 77 adjustably carried by the bracket 76. An anti-friction roller 78 is mounted upon the end of the arm 77 and is arranged to be in continual rolling 4 t contact with the belt upon that side `opposite from the loose-pulley element. As the loose-pulley element 37 is moved toward the fast pulley element 56 it forces the belt 55 not only against the belt-groove face 59 but also againstthe roller 78 which slightly deforms the belt as at 79, which deformation is illustrated in exaggeration in Fig. 4. Thus, when the pressure on the loose-pulley element is relaxed the` roller 78 will force the `belt and consequently the loose-pulley element away from the fast pulley element, thereby moving the belt away from driving relation with the fast pulley element. .The belt will then ride on the bottom wall 66 of the loose-pullcy i element which will rotate idly on the shaft 10.

The stop-motion mechanism comprises a face-cam 80 formed as an integral portion of the flange 58 of the fast pulley element 56. The Icam 80 includes a recess 81 including a stop-shoulder 82, as best seen in Fig. 4.` A stop-arm 83 formed to be seated in the recess 81 includes a strap portion 84 that loosely encircles the sleeve 60 of the fast pulley element. The stop-arm 83 is carried by a lever 85 which at its lower end is provided with a strap-portion 86 encircling a lateral enlargement of the strap-portion 84 of the stop-arm and held thereon by a split-ring 87 fitted in a groove in the strap-portion 84 of the stop-arm. At its upper end, the lever 85 is pivoted by means of a pivot pin 88 to a bracket 89 that is secured to the standard 2 by screws 90.

The free end of the stop-arm 83 is pivoted by means Y of a pivot pin 91 to a yoke 92 upon the lower end of a resiliently-centered stop-rod 93. The stop-rod 93 slidably extends through a center-block 94 that is fixed to an arm 95 integral with the lever 85 and extending laterally therefrom. A pair of coiled compression springs96 and 97 encircle the stop-rod 93, the spring 96 acting between the center-blocki94 and the yoke 92 and the spring 97 acting betweenV the center-blo`ck 94 and a washer 98 held upon the upper end of the stop-rod 93 by a pair of nuts 99.

, It will be apparent that with the stop-motion mechanism thrown into operative relation with the stop-cam by pivoting the lever about its pivot pin 88, the stop-arm 83 will be in sliding engagement with the face of the cam 80 until the recess 81 comes around. The stop-arm 83 will then be engaged by the stop-shoulder 82 and will fall into the recess 81, thusstopping the machine. The

momentum of the moving parts of the machine will he initially absorbed in the spring 97 which resists the depression of the stop-rod 83. The rebound in the spring 97 will act against the spring 96, which springs thus resiliently center the stop-rod 93.

The spring arm 74, which is the actuating elementfor sliding the loose-pulley element axially of the shaft 10, is tixcd at its lower end, as by screws 100, to the bracket 76. The spring-arm 74 is arranged to engage the anti-friction ball 73 at a point intermediate its ends andthe upper end thereof is located between opposed knife-edges 101 (see Fig. l) formed in a block 102 carried at the end of a rod 103 that is, in turn, carried by the arm 95. As the lever 85 is moved about its pivot 88, `the rod 103 through the knife-edges 101, will ilex the spring-arm 74 toward or away from the anti-friction ball 73 carried by the loose-pulley element 57. When the spring arm 74 is filexed toward the ball 73, it resiliently` urges the loosei pulley elementv`57 toward the fast pulley element 56.

,tion of the loose-pulley element 57 toward the fast pulley element, or to secure a predetermined pressure between the belt 55 and the opposed belt-groove faces 59 and 67, is not critical as would be the case if rigid linkages were employed.V

As hereinabove pointed out, as the lever 85 isrnoved about its pivot 88 clockwise as seen in Fig. l, the loosepulley element 57 is moved toward the fast pulley element 56 to clutch the belt 55 to the fast pulley element, and

pulley element, and the stop-armf83` issmovednintoengagement withthe cam-face of-cam 80 andas the recess 81 comes aroundVthe .stop-arm-wilh contact.A the-v stop- Ishoulder 82l andY fallinto the recess 81! to..stopthen machine. Means are providediory swinging` the.. lever-.85 about its pivot,whichmeans includes an arm 104 secured to the arrn 95 of the lever 85 by screws :105 and/extending Ito they interiorV of the standard 2., kTsthe .endfofmthe arm 104 there is pivotally connected alinkfy106 whichislalso f pivotally connected to a rod"107 disposed vertically. with- 1 rvinthestandard 2 for longitudinal slidingmovements A spring 108 vis coiled abouttherod 107. andheld incornpression between a bushing 109" Aformedv in-thelstadard and through which bushing the yrod"107 slidablyjext'enids, .and a collar 110 xed 'tothe rod l107' by a set-s'crewllll. v

vThe collar 110 is formed to'providefvertically stepped shoulders 112 and 113`which are" designed to` cooperate successively with the end 114 of onearm 115 lof'a bellcrank lever 116, which arm thus holdsl the rod 1,07 1elevated .against the action of spring 108 inieither one oftwo polsitions. The bell-crank lever 116 is txed to a rod'117 that is arranged transversely of the bed 1 and pivotallymount- "ed in the side walls thereof. A cam-plate 118"'is` adjustably'tixed to the periphery of thecarrf 25 by'setlscrews 1119 that' extend through slots 120 in the cam-plate' and/are.v threaded into thel cam 25, which cam-'plate is" designed to contact and thereby pivot the other'armi 121 o'fthe bell-crank lever 116. The 'cam-plate. 119'Y includes a' 'rst surface 122 i'sso designed that' whenfthear'm v121 ofthe@ bell-crank lever is depressed thereby,A the other .arm 115 cam surfacer 122 and asecond cam surface 123. The cam of theI lever willbe pivoted onlyenough to move the'e'nd 114 thereof from under the shoulder.113 ofthe coll'a110 n but' not enough to move'it fromun'derthe shoulde'r.11y2,

j so that the rod 107 will move down under ther action of,v "spring 108 only for thejvertical distance'btween" the shoulders 112 and 113. The second canrsurface 123 is `designed to depress the lever arm 121- enough to 'cause "'trhe'end 114 of the other lever arm' 115 toA movefrom'under i the shoulder 112 of the collar 110`and thus release therody 107 for 'movement downwardly tovv its end position' under the action of spring 108.

A A's'will be evident, downward 'movement'of the rod107 willl pivot the lever 85 'counterclockwise to declut'chthe driving Vbelt'f55 and to move the stop mechanism' into operation. The downward movement of therod 107'for the distance between the' shoulders 112 and 113 is designed to release the loose-pulley element 57 for movement away "fromthe fastpulley element 56 for a distance great enough to declutch the belt 55 from the fast'pulley "elemerit 56, but not enough to bring the stop mechanism into" operation. `Thus, while vthe armf1'21` rides on the camsurface 122 the machine will continue vto'opeiate but ywill be disconnected from the vdrive means andv thus coasting.

' The length of the cam-'surface 122 may be varied but in the disclosed machine it is designed -to represent two complete stitching cycles. When the arm 121" is raised onto thelcam-surface 123, the rod 107 will move downwardly enough to bring the stop-motion mechanism into"opera raised against the action of spring" 108',1the'1evert85v willbey tion. It Vwill also be evident that whenthe-rod' 1 07' is swung to retract the stop-motion rri'echanism"` a'ndf'to clutch the'driving belt 55 to the tast' pulley element 56. -Acol tension spring 124 is lconnected at one end to the varm 115. of the bell-crank lever 116'and atthe other end to the frame to b iasthe lever 116'so that when the rod`107 is raised, the end '114 will move under the shoulders71l12 and-113 to Yhold the rod in-raised positiom To facilitate '125-pivoted'to'thebaseiSiby a pivotLpin'126-landaving "of'theo'cam 25. Towards this end .the bell-crank lever 116 ...extendsethrough an-taperture.129 in the base 5 tot a foot treadl". not ishown or` 'otherl 'suitable meansV for exerting `afpi1ll.=n`fthe"chain-128"and having a' secondarm 130 carrying a roller 131 at itsv free .end that underlies 'theend VfoftheA rod-"107. A"spring"132.is provided for biasingthe bell-crank leverX 125 about its.pivot .with the" arm.130 down.

` Theillustrat'ed:machinefis designed to produce a;1r6 stitch' tack'forlsecuring fourhole buttons to a'v garment inthelcustom'ary manner. Consequently, the'cam25' is geared to makeonecomplete revolution inr 16 stitchesor in '16 revolutionsof the bed-shaft 10 and attheV end of 'theta'cking cycle, the stop-motion mechanism is'brought `i`nto` operation to'bring" themachine to a stop. Inladdi- .tion toproducing 16'stitch tacks; the present machine'ls providedwith means for bringing the stop-moti'on'mechanismntoop'eration' half-way.V through the stitching' 'cycle, thus producing'an Sistitch tack upon each actuatlon'of the machine'. as 4infsewing two-hole buttons to a garment,

andproducing'two Sastitch tacks upon each revolution i's.txedby"rneans ofa pin 133to the rod 117, which rod isidisp'osedtransversely of the bed 1 and pivotally mounted. in the walls thereof. The' mounting for the rod-117 consists' of a pivot pin134 rotatably mounted in a side wall o f the bed 1 and having a reduced end portion135 threaded"into' '.the end` of the rod 117. The rod 117 is 'held againstaxialsliding movement by the head 136.015v

j thetpin1j34gthe sidewall ofthe bed 1 being held between 'opposite' end;"therod.117 is mounted in a sleeve 137 for head-136A )and ,the` end of the rod 117. At vits r'o'tationand sliding"relativethereto which sleeve. is in turncarried by a'side wall ot the bed 1 for Vrotation and sli-ding'relative to the bed 1.

Theone 'ernd138 of the rod.117 adjacent the sleeve 1-37 isvfslabb'ed. volf to iform opposed parallel sides. A- lever 139having' ahub' 140 provided with aytransverse aperture corresponding to the cross-section ofthe end 138 of the rodp117,iis mounted `onthe rod 117 for sliding movementlongitudinally thereof and held against rotation relative tothe rod by thekey-etect of thecross-section. of

` theend 138 of the rod. A spring 141 isV coiled. about 'therod 1171and held in' compressionbetweenr thehub 140 of the'leverl 139 and a collar 142` xed to therod, whichv thus Vurges the; lever y139 into engagementwith the end `4 ofthe sleeve'137 and consequently. urgesthe sleeve 137 outwardly or off the end of the rod 117.. At its outer endrthe sleeve 137 is provided with an karm 143 having a ngeripiece 144 upon the end thereof. .to facilitate' rotating the same, which arm ,is-.designed to cooperate with a plate 145. to limit slidingemovementof "the sleeve 137 relative to the rod 117. The plate 145, which is secured to the side wall of the bed 1 by Yscrews spaced axially of the rod 117.

It will be apparent that asr the arm 143 is rotated relative to the rod 117 and relative to the plate 145,v from a position on the rest-point 151 to a position on the restpoint 152, the sleeve 137 will'be moved axially of the rod 117 againstthe spring 141 by the cam face 150, which movement of the -sleeve 137 is imparted to the hub 140 of the lever139. Thelever 139, which is.normallyout of the path of travel of the cam-plate 118on the periphery of the cam 25, as illustratedin Fig; 5; will thus be moved into v operative relation with theA same. *"When `the "camplate -1'18 isjrotated around, itwill-*cooperate"withfthe levert139ur`fth samefmanner as itcooperates' with-"the stitches.

arm 121 Aof the bell-crankir lever 116.` Sincevthe lever 139 is keyed to the rod 117 bythe slabbed-ot cross-section of the end 138, the moving ofthe end of the lever 139 by the cam-plate 118 will rotate the rod 117 and thus the bell-crank lever 116 which is alsofixed to the rod 117 against rotation relative thereto. Thus,Y since the bell-crank lever 116 is pivoted in the; same manner as if it had been actuated by the cam-plate 118, the` stopmotion mechanism is also actuated in the same manner as hereinbefore described with relation to the bell-crank lever` 116. Thus, the stop-motion mechanism will be actuated `upon each half of a revolution of the camZS, which in the illustratedmachine is at the end of eight When the arm 143 is rotated from `the `restpoint 15,2 to the rest-point 151, the lever 139 is'moved by thespring 141 Aout of the path of travelof the camplate118, and the stop-motion mechanism will be brought into the `operation only after a complete revolution of t the cam 25, which inthe illustrated machine represents sixteen stitches. The end walls `149 of the slot 148 are so positioned that when the` stop-arm 143 is swung into contact with the same, it `will be on one of the rest points 151 or 152 respectively.

Having thus sets forth the naturev of the invention, what we claim herein is:

1. In a sewing machine having a frame, a rotary shaft journaled in saidframe, a belt-pulley having a fast pulley element fixed to said shaft and a complemental loose pulley element mounted upon said shaft for rotation and translation relative thereto, a lever pivoted to the frame on an axis in a plane normal to said shaft, a rod mounted in said frame for axial sliding` movement and arranged 1n a plane normal to `said shaft, operative connections between said rod and said lever to pivot the latter upon sliding movement of said rod, a spring for urging said rod in one direction, manual means for moving said rod in the other directiona collar on said rod,`saidcollar having a pair of stepped shoulders, a pivoted lever-arm adapted to cooperate with said shoulders individually toy hold said rod against the action of said spring in a selected one of two positions, said lever arm being adapted to be swung successively from a position in coopera- 'tion with one of said shoulders, to a position `in cooperation with the other of said shoulders, and to a position in which it is out of cooperation with both of said shoulders,

means responsive to a predetermined number of revolutions o f said rotary shaft for swinging said lever` to its successive positions, stop-motion mechanismA comprisling a stop-Shoulder carried by said fast pulley element and a resiliently-centered stop-arm carried by said lever and adapted to cooperate with said stop-shoulder to stop rotation of said shaft, said stop-arm being in cooperative relation with said stop-shoulder only when said shoulders on said rod are released by said lever-arm for movement of said rod under the action of said spring to swing said lever, and means for moving said loose pulley element toward driving `relation with said fast pulley element in which a driving belt is frictionally clamped to said fast pulley element, `said means comprising a leaf spring fixed at one end to said frame, at the other end operatively connected to said lever to be liexed thereby upon swinging movement of said lever, and. at an intermediate portion engaging said loose pulley element to slide the same axially of the shaft upon exing of said` leaf spring, said; Y' loose pulley element being in driving relation :with said fast 4pulley element under the action of said leaf spring only when said lever-arm is in cooperation with that one of said stepped shoulders which isadapted to hold said rod in the maximum position in the direction against the action of said spring. l i' 4 2. In a sewing machine having a Yframe, a rotaryshaft journaled in said frame, driving ymeans for delivering ,4 power to said shaft comprising a belt-pulley and clutch- Ving means foi' coupling a driving lbelt in driving relation` yio simultaneously releasing said stop-motionmechanism to Aperrnitrotation'cif'said shaft, means responsive to a predetermined number of revolutions of said shaft for unconpling the driving belt from said belt-pulley and for actuating s aid stop-motionmechanism to stop rotationof said shaft, said last-mentioned means including a rotary actuating element, operative connectionsbetween said actuating element and shaftfor driving the element at a predetermined ratio with respect to the rotation of said shaft, afirrst member arranged in cooperative relation with said actuating element and a second member arranged to be moved selectively into and out of cooperative-relation with said actuating element at a point spaced angularly relative to said actuating element from said first member, whereby said driving means may be uncoupled from said shaft and said stop-motion mechanism will be actuated to stop `rotation of said shaft at the; completion of a cycle of rotation of said rotary actuating element and selectively at an intermediate pointin the cycle.

' cooperate with said cam to be pivoted thereby in one direcvtion about the pivot-axis of said rod and thereby pivot 35 said rod, means for biasing `said'first leverarm inthe other direction about the pivot-axis of said rod, operative connections between said rod and said stop-motion mechanism to actuate the `latter upon `pivotal `movement of said rod, a second lever-arm mounted on said shaft for axial sliding relative theretoA and keyed to said shaft for pivotal movement therewith, said second lever-arm being arranged to cooperate with said cam at a pointangularly spaced `with respect to the axis of said cam from said first lever-arm, and manual means for selectively moving said `second lever-arm into and out of cooperative relation with saidV cam.

4. In a sewing machine having a frame, a rotary shaft journaled in said frame, stitching mechanism operated by said shaft and defining a point of stitch-formation, a work-clamp, means for jogging said work-clamp relative tothe point of stitch-formation comprising a cam-shaft journaled in said frame,` operative connections between said rotary shaft and said cam-shaft for rotating the latter upon rotation of the rotary shaft at a predetermined ratio tothe rotation of the rotary shaft, a cam fixed to said l cam-shaft and operative `connections between said cam and said `work-clamp for jogging the latter through a predetermined stitching cycle upon each revolution of the cam-shaft, stop-motionmechanism for stopping rotation of said rotary shaft `and means for actuating said stopmotion mechanism upon completion of each` stitching cycle comprising a cam-surface on said cam, a rod pivotally mounted transversely of said frame, a first `member fixed to `said rod and arranged to cooperate with said cam- `Surface to pivot said rod, and operative connections between Isaid rod and `said stop-motion mechanism to actuate the latteiupon pivotal movement of said rodpand means for selectively actuating said stop-motion mechanism at an intermediate point in the stitching cycle comprising a second member mounted on said rod for axial sliding movement and keyed to said rod for pivotal move- Ynient therewith, said `second member being arranged in operative ,relation withsaidcam-surface, and manual means for moving said second member linto and out of f operative relation with said cam-surface.`

5. In a sewing machine having a frame, a rotary shaft journaled in said frame, drive means for said shaft in cluding clutch means for selectively coupling and uncoupling a drive belt in driving relation to said shaft, stopmotion mechanism including a stop-shoulder associated with said shaft for unitary rotation and a resiliently centered stop-arm movable into and out of cooperation with said stop-shoulder and adapted when in cooperation with said stop-shoulder to stop rotation of said shaft, a lever pivoted to said frame on an axis in a plane normal to said shaft, operative connections between said lever and said clutch means and stop-motion mechanism for successively uncoupling said clutch means and actuating said stopmotion mechanism upon continued motion of said lever, a rod mounted in said frame for axial sliding movement and arranged in a plane normal to said shaft, operative connections between said rod and said lever for pivoting said lever upon axial sliding movement of said rod, a spring for urging said rod in the direction to uncouple said clutch means and actuate said stop-motion mechanism and manual means for moving said rod in the other direction, a collar on said rod, said collar having a pair of shoulders spaced longitudinally of said rod, a pivoted lever arm cooperating individually with said shoulders to hold said rod against the action of said spring, said lever arm being swingable successively from a position in cooperation with the rst of said shoulders to a position in cooperation with the second of said shoulders and then to a position in which it is out of cooperation with both of said shoulders, said shoulders being disposed along said shaft so that when said lever-arm is in cooperation with said first shoulder said clutch means is coupled to said shaft and said stop motion mechanism is out of operation when said lever-arm is in cooperation with the second of said shoulders, said clutch means is uncoupled from said shaft and said stop-motion mechanism is out of operation, and when said lever-arm moves out of cooperation with the second of said shoulders said stop-motion mechanism will be actuated, and means responsive to a predetermined number of revolutions of said rotary shaft for swinging said lever to its successive positions.

References Cited in the le of this patent UNITED STATES PATENTS 329,753 Ludlow Nov. 3, 1885 1,093,241 Barron Apr. 14, 1914 1,843,534 Allen Feb. 2, 1932 2,440,227 Wood Apr. 20, 1948 2,540,987 McCann Feb. 6, 1951 2,721,526 Ivanko Oct. 25, 1955

Images