US1812895A - Feeding mechanism for sewing machines - Google Patents

Description

July 1931- c. w. MUELLER FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 5 Sheets-Sheet 1 A TTORNE Y.

July 7, 1931. c, w, MUELLER 1,812,895

FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 5 Sheets-Sheet 2 47 w 'r l/ I Hd''\9 //0 T" t; 27 55 i v 35 54' IT? (i Z4 I July 7; 1931. 'w MUELLER 1,812,895

FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 s Sheets-Sheet 5 4 N 2 H Q Q i n o I j i q I l \D fi \iw i I 1 0 $3 I I l l I b z\ I m f ,l x {I Q & I x I \3 1 4 3 f m 1; Q a w b Q I I (q @3 INVENTOR. 'Cfiar sWMzeZZa;

"5555 f 177 15555 I "707T ATTORNEY.

C. W. MUELLER FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927' 5 Sheets-Sheet 4 1 t I Mud- July 7, 1931. c. w. MUELLER FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 5 Sheets-Sheet 5 I .YVEN TOR. CfiarZesWlfudla;

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2 m6 m9 vm2 Patented July 7, 1931 UNITED STATES PATENT OFFICE CHABLESW. MUELLER, 0F: SILLOUIS, MISSOURI, ASSIGNOR TO LEVIIS INVISIBLE STITCH MACHINE-1 COMPANY, OF ST. LOUIS, MISSOURLiS CORPORATION OF MAINE FEEDING MECHANISM FOR SEWVING MACHINES Application filed April 26,

This invention relates to new and useful improvements in feeding mechanisms for sewing machines generally, although the invention is more especially directed to a feed- 5 ing mechanismfor use in blind stitch sewing machines used in felling operations.

One of theprincipal objects of the invention is to provide upper and lower feeding mechanisms for intermittently feeding su- :perpose-d layers of materials .past'a stitch forming mechanism, the upper layer having its marginal edge portion infolded and \disposed in a substantially vertical plane for engagement by the upper feed dog whereby both the base layer and the foldedupturned edge portion of the upper layer will be simultaneously fed Without having a drag imparted to said folded upturned'edge portion of the upper layer.

Another object of the invention is to provide upper and lower feeding mechanisms of the character described, together with means for withdrawing both the upper and lower feed dogs from operative positions whereby the material or work maybe either inserted in themachine or withdrawn therefrom.

W ith these and other'objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the. description, the appended claims, and the several views illustratedin the accompanying drawings.

Inthe accompanying drawings which illus- 5 irate one form of my invention,

Figure 1 is a, front elevation of the stitching head and the work arm which form parts of a blind stitch sewing machine equipped with .my invention,

Figure 2 is a left handelevation thereof, Figure 3 is a rear elevation of the machine. Figure 4 is a perspective view of the upper feed mechanism and the associated parts,

Figure 5 is a plan view of the cam for operating the upper feed dog,

Fi ure 6 is an enlarged sectional W'ew 'showingthe means for permitting the lower feed dog to be depressed,

Figure .7 is an end elevation showing the normal position ofthe'lower feeddogin full 1927. Serial No. 186,673.

lines and the depressed position of the dog in dotted lines,

Figure 8 is a perspective view of the operating lever for depressing the lower feed Figure '9 is an enlarged top plan view of the main presser foot showing the upper feed dog associated therewith,

Figure 10 is a bottom plan view thereof,

Figure 11 is a transverse sectional view taken on the line ll11 of Figure 9,

Figure 12 is a perspective view of the upper feed dog and feed bar, and

' Figure 13 is a side elevation of the main presser foot showing the shank of the upper iced dog supported in a guide fixed to said oot.

Like reference numerals designate corre sponding parts throughout the figures of the drawings.

Referring to the accompanying drawings, I have shown in Figure 1 a base layer A which may be-the body fabric of a coat and a superposed layer B which may be the lining therefor. The present invention is especially adapted for felling the lining B to the base layer or body fabric A, and to this end the superposed layer B has its marginal edge portion infolded as shown at b, and turned up into a vertical plane, as indicated at b. By means of the sewing machine illustrated in the accompanying drawings, a line of blind stitches is formed which is. disposed adjacent the meeting point between the base layer A and the upturned portion 5 of the superposed layer, these stitches serving to join the two layers along a line parallel with the folded edge of the superposed layer. After the stitching operation, the upturned folded portion of the superposed layer is returned to normal or horizontal position, thus covering the line of blind stitches formed by said stitching operation.

The blind stitch sewing machine shown in the accompanying drawings is of the Lewis type and comprises a frame which includes a base 5, a laterally extending work arm 6, a standard 7 an overhanging arm 8, and a stitching head 9 which is secured to the free 611(1- Of the overhanging 8 and dis stitching head 9 and is adapted to be driven posed above the outer end of the work arm 6.

The machine includes a stitch forming mechanism which I have indicated as a whole by the reference numeral 10, and a work presenting mechanism which I have indi- '8 and across the standard 7. A grooved pulley 13 is fixed to the. shaft 12 opposite the by any suitable power.

The work presenting mechanism is shown and .claimed'in my co-pending application Serial No. 186,674, filed April 26, 1927 This -work presenting mechanism includes a main presser foot 14 whichis fixed to the stitching head 9, a work clamp 15 which cooperates with the work below the main presser foot, -a lower feeding mechanism '16, an upper feeding mechanism 17,: alower plunger mechanism 18, an upper plunger mechanism and a movable presser foot 20.

The stitch forming'mechanism '10 includes will be oscillated along the stub shaft 24 -shaft;24 secured to the stitching head 9. The

needle lever 23 is mounted on the stubazshaft 24, not only for oscillatory movements about said shaft, but also for lateral movements longitudinally of said shaft. The other arm of the needle lever 23 is pivotally connected with the lower end of a link 27 the upper end of said link being pivotally connected as at 28 to one arm of a bell crank lever 30 which is journaled on the stitching head 9,

the other arm 31 of the bell crank lever being pivotally connected as at 32 with the lower end of a link 33. The upper end of the link '33 is connected to an eccentricpin 34 formed on a jack shaft 35 which is journaled in the stitching head 9 below the mainshaft 12 and extends in parallelism therewith. A 1 to 1 gear coupling 35 connects the main shaft 12 and the jack shaft 35 and consequently during each complete rotation of the main shaft 12 the needle 21 is thereby given a complete reciprocation in the line of feed.

It is desirable to impart a shogging motion to the needle 21 whereby the needle during one reciprocation will enter the base layer and emerge therefrom and whereby during the following reciprocation theneedle will enter. the folded upturned portion ofthe lining. To this end, I have provided the following mechanism which will impart a positive lateral shifting movement to the needle lever 23: 7

The needle lever 23 is formed with a hub extension 36 journaled on the stubshaft 24 and this hub extension is formed with a pcripheral groove 37 which receives a slide block 38 secured to the lower end of an arm 39 of a bell crank lever 40, said lever 40 being fulcrumed as at 41 to the stitching head 9. The other arm 42 of the bell crank lever is provided at its outer end with a fork 43 for engagement with an actuating cam 44. The cam 44 is fixed to a shaft 45 which is journaled in the stitching'head 9 and has its longitudinal axis disposed in parallelism with the line of feed. The cam shaft 45 is rotated once to every two revolutions of the main shaft 12. In order to thus rotate the cam shaft 45, I have journaled a substantially vertical shaft 46 on the stitching head 9, and this shaft 46 is driven from the gear coupling 35 through the medium of'a gear 47 fixed to said shaft 46. Fixed to the shaft 46 is a worm 48 which drives a pinion 49 fixed to the cam shaft 45. The cam 44 is of the peripheral type and includes-two separated concentric portions. These concentric portions while. the needle is in its forward position.

The cam shaft 45 rotates in an anti-clockwise direction as viewed from the front of the --machine .and consequently when one concentric portion is disposed above the axisof the cam shaft, the bell crank lever 40 is in a position whereby the needle will reciprocate in its lefthand positiomwhereas when the other concentric portion of the cam is above the axis thereof, the bell crank 40 will be shifted so that the needle will reciprocate in its righthand position.

Cooperating with the needle 21 to form a line of straight-away stitches is a rotary hook 52, and this hook is given two complete rotations to each reciprocation of the needle.

The hook is fixed to a shaft 53 (see Figure and fixed tothis shaft is a bevel gear 54 which is driven from a corresponding bevel gear 55 fixed on the vertical shaft 46. Inasmuch as the gear coupling 5455 is a 1 to 1 coupling, the hook 52 will be rotated once during each rotation of the vertical l shaft 46.

The presser foot 14 is fixedly secured to the lower portion of the stitching head 9,-and cooperating with the under face of the presser foot is the work clamp 15, the lower feed .mechanlsm 16, and the lower plunger mechanism 18.

The lower feeding mechanism 16 includes .a feed dog 56 whichis of the 4-motion type,

and the mechanism for operating this feed dog is substantially identical with that shown 1n my former Patent 1,588,132, issued June 8, 1926. The backward and forward movement of the feed dog is obtained through the medium of a rock shaft 57, which'I term the fe d trave sha t, a dithe up, an do n im VQmEIJ Qf the :feeddog is. Qbtained from arocikshaft-58,.Whi h1 te. ?m.- h f e lif shaft. These rock shafts- 57, 5.8,eXtendlon- .git dinal yw thin h Work-arm; G n a e their righthand ends journaled in a bearing lug 59 and theirlefthand ends j ournaled in bearings formed in ablock60 which is de- ,tachably secured to thelefthand .end ofzthe work var nby screwsfil. Fixedto the outer end ofrthe ffeed travel shaf 57 is a rock 1 arm .62, and .pivotally connecting the outer ,lendsiof the rock arm and the forward extremityvof the feed dog 56 is a link-63. The rock varm 62 ,extendsin a generalvertical direction and. thelink extendsin ageneral horizontal direction. Thus upon movement of the rock arm.62, thelink 6-3 will impart back- .wardand forward movements tothe feed -20.

as at. 651, to; the; upper; end of a substantially dog-56. Thefeed dog'is pivotallyconneoted,

vertically disposedlink-65, the lower end of theglink,beingpivotally connected, as at 66, tothe horizontal arm 67 of abell crank lever 68-,.;the v.ertical arm 69 of thebellcrank lever being ,pivotally connected as; at 7 O to one end ofja link;71, the other end of said link 71 being pivqtally connected as at ;72,to the outer end ,of'a vertically disposed rock arm 7 3 fixed to thefeed'lift shaft; 5.8. In order to maintain the feed surface of the feed dog in a substantially horizontal plane during the sfeed.movements thereof, I have provided a -,spring 7 i which is connected by a pin 75 fiXedtO thelink 65 and a pendent tail 76 fixed to the feed dog. ;It vwill, therefore, be observed that upon rocking movement of the feed lift shaftfisathe vertical link 65 Will be bodily raised and lowered, and consequently the feed dogwi-ll be given itsup and down movements. By proper timing of the shafts 57 and 5 8,,a 1-way feedmotion will ;be imparted to said I dog.

The bell crank lever 568 is pivotally connected, as at 7:7 toa head 78 secured to the lowe d o a g1 dep st7 sa d ea a 2post :fQrming a vertically movable carrier.

{The post 7 9'gis mounted for V rtical sliding moyements-inabore formed inthe end-block 160, andithisblockisformed with aseat- 80 for engagement by-the head 78 to limit theup- JVard-Inovement of the carrier. The carrier ,isnorm ly el in it highe p si-t mt is, withthe head -78 bearing against-the seat 80,-b.y mean of a fi sp ing-8 th i ne .e dof hich i gidly s u e ath Wor arm 6; and the outer end thereof is disposed under the head 7850 as to yieldably .retain .the carrier inits higllest position. The upper find .ofthe 081 37 9 projects above theblock 6O and v carries a pair of rearwardly projecting ar-ms 82f82 between which ispivoted, as at 6. the w rk c mp 1 E ren- 1, the f regOi-Dg, it Will be observed that when the feed.- dog 6 elevated t its high- ,est position, the fulcrumof the bell crank -;lever'.68 is then shifted to the pivot 66, and consequently the last part of the rocking .movement of the crank arm 73 will cause the .bell crank lever 68to be moved downwardly about itsfulcrum 66, thus lowering the work clamp 15. The parts are so timed that the work clamp islowered prior to the feeding movement of the feed dog. The reverse order of movement will take place at substantially thetimethe feed dog reaches the end of its feeding stroke, thus causing the clamp to engage the fabric and clamp the latter against thebottom of the main presser foot14c so as to retain the fabric against movement while the needle is penetrating the material and emerging therefrom.

In order to rock the feedtravel shaft 57 and the feed lift shaft 58, I provide the main shaft 12with two eccentrics. A con .nection rod '84: has itsupper. end engageable with one of said eccentrics and has its lower end pivot-ally connected to a rock arm fixed to the feed travel shaft 57. A connection rod 87- has its upper end engageable with theother eccentric mounted on the main shaft and has its lower end pivotally connected to arock arm fixed to the feed lift shaft 58. .The connection rods 84 and87 are disposed within the standard 7 of the machineframe, and the eccentrics which are mounted on the main shaft-for actuating these rods are timed so as to bring about a ti-motion movement to the feed dog.

In order to position the baselayer A whereby the needle 21 will penetrate and emerge therefrom, I have provided the lower plunger mechanism 18 which includes a vertically reciprocatory plunger 91 which is disposed directly below an opening 90 formed in the presser foot ltand directly below the stub shaft 24 which supports the needle-lever 23. The plunger 91 is reciprocated vertically through the medium of a plunger shaft 92 which is journaled in and extends longitudinally ofthe work arm 6, said plunger shaft 92 being oscillated by the main shaft 12 through the mediumof aconnection which I have indicated as a wholeby the reference numeral 93. This particular plunger operating mechanism forms the subject matter of my vco-pending application, Serial No. 186,672, filed April 26, 1927, and it is there fore believed that further description will be unnecessary.

The main presser foot 14 includes a heel 94 ,and a toe 95, the opening 90 being located the-rebetween. The foot 14 includes at its front end an offset portion 96 which is spaced from the toe to form a longitudinally ex tending and vertically disposed guideway 97 for the upturned folded portion Z) of the lining B. This guideway extends in the line of feed and includes a vertical wall 98 which is on thelefthand side of the path of needle.

oscillation. The wall 98 extends rearwardly 1 past the opening 90 and terminates in the heel 94, as indicated at 99 in Fig.10. Cooperating with the guide wall 98 is the horizontally movable presser foot 20 and horizontally movable upper plunger 100, the foot 20 extending substantially across an opening 101 formed in the wall 98 and the plunger 100 being mount-ed for reciprocatory movements through said opening 101 to project the node 'of the upturned folded portion Z) into the path of needle oscillation. Inasmuch as the 7 of the presser foot 14 whereby the said teeth I specific construction of the movable presser foot 20, the upper plunger 100, the means for withdrawing said movable presser foot 20 from operative position, and the means for actuating the upper plunger is shown, de-

scribed and claimed in my 'co-pending application above mentioned, Serial No. 186,672, it is thought that further description of these parts will be unnecessary.

i The upper feed mechanism 17 includes a feed dog102 which is connected to the feed bar 103 having an upwardly extendingand will cooperate with the guiding wall 98 and clamp the upturned folded edge portion 6 therebetween. The feed dog is supported for 7 its horizontal movements by means of a guide 106 which is attached to the lefthand side of the presser foot 14, said guide including upperand lower horizontal arms 107 and 108 respectively for receiving the shank of the feed dog 102. Forimparting backward and forward movements to the feed dog 102, that is, movements in the line of feed, I have provided an actuating lever 109 which is fulcrumed on a horizontal pivot 110 fixed to the stitching head 9. The lower arm 111 of said lever is connected to the rear end of the feed bar 103 through the medium of a horizontal. pivotalconnection 112, and a vertical pivotal connection 113. The upper arm 114 of said lever is provided with a segmental slot 115 to which is adjustably connected as at 116 the rear end of alink 117 which has its forward I end pivoted to an eccentric pin 119 fixed to the shaft 35. Consequently," during each complete rotation of the main shaft 12, the

lever 109 will be given a complete reciprocation, and as a result the feed dog 102 will be given its backward and forward movements. In order to reciprocate the feed dog 102 laterally, that is, toward and away from the upturned edge portion Z) of the lining B, I have provided an actuating lever 120 which is vertically disposed and is mounted to oscillate in a plane at right angles to the lever 109. The lever 120 is provided at its lower end with a groove 121 for continuous although sliding contact with the guide plate 104 carried by the feed bar 103 so as topermit said feed bar to'move longitudinally in the line of feed. The lever 120 is fulcrumed intermediate its ends on a crank pin 122 fixed to a crank shaft 123 journaled in the stitching head 9. The crank shaft has its longitudinal axis in the line of feed, and secured to the rear end of this crankshaft is a rock arm'124. A spring 125 has one end fixed'to the rock arm 124 and the other end fixedto the stitching head 9. The upperend of the actuating lever 120 carries a roller 126 for engagement with a peripheral cam 127 fixed on the shaft 45. The cam 127 is provided with oppositely disposed high points or concentric portions 128128 and opposed intermediate eccentric portions 129129, the former having a common radius. A spring 130 has one end connected to the upper arm of the lever'120 and the other end connected to the stitching head 9. The spring 130functions to yieldably retain the-cam roller 126 in'constantengagement with the actuating cam 127. The spring 125 serves'to yieldably retain the cam shaft '123'against movement, and consequently yieldably retain the fulcrum of the lever 120 against movement. 7 I

Thus "when a seam or other abnormally thick portion in the upturned folded portion 6 of the lining is being fed through the machine, the fulcrum 122 of the lever 120 will yield and thereby avoidany choking action to the feed of the material which would otherwise occur by reason of the guiding wall 9 being immovable. V I

In order to depress the lower feed dog 56 from working position relative to the presser foot 14, and to simultaneously withdraw the upper feed dog 102 laterally away from working position, I have provided the following manually controlled mechanism In order to permit the work to be inserted in the machine or to be withdrawn therefrom, it is'desirable to provide means for depressing the lower feed dog 56 from co-operative relation with the main presser foot 14 and to move the upper feed dog 102 laterally away from the 'fixed guiding wall 98. I have, therefore, provided a manually operable means for this purpose. This manually operable means includes a lever 131 which is journaled on the plunger operating shaft 92 through the medium of two bearing arms 132-132. The lever 131 extends longitudinally of the work arm 6 and has its outer end provided with an offset projection 133 which engages directly above the head 78 of the post 7 9 to which the bell crank lever 68 of the lower feed mechanism is pivoted. The inner end of the lever 131 is provided with an operating extension 134 which is normally disposed ing a; feed dog, means for reciprocating said bar-longitudinally in'the linev of feed, an oscillatory shaft extending parallel to the line of feed'and having a crank pin, a lever fulcrumed on said crank pin and having one end operatively connected to said feed bar for reciprocating the latter in a plane at substantially right angles to the longitudinal axis of the feed bar, and means for oscillating said shaft to shift the fulcrum of the lever for moving the feed dog out of operative working position.

7. In a' feeding mechanism for sewing machines, the combination with a feed bar having a feed dog, means for reciprocating said bar longitudinally in the line of feed, an oscillatory shaft extending parallel to the line of feed and having a crank pin, a. lever fulcrumed on said crank pin and having one end operativelyconnected to said feed bar for reciprocating the latter in a plane at substantially right angles to the longitudinal axis of the feed bar, means for yieldably retaining said shaftagainst oscillatory movements, and means for oscillating said shaft against the tension of said yieldable means to shift the fulcrum of the lever for moving a the feed dog out of operative working position.

8. In a feeding mechanism for sewing machines, the combination with a feed bar having a feed dog,-1neans= for reciprocating said bar longitudinally in'the line of feed, an oscillatory shaft extending parallel to the line of feed and having a crank pin, a lever fulcrumed on said crank pin and having one end' operatively connected to saidfeed bar for reciprocating the latter in a plane at substantially right angles to the longitudinal axis of thefeedbar, means for yieldably retaining said shaft against'oscillatory. movements, means for oscillating said leverin cluding avperipheral cam having direct contact with the other end of the lever, a spring for maintaining said lever in contact with said cam, and meansfor oscillating said shaft, against the tension of said yieldable means to shift the, fulcrum oflthe lever for moving the fee'd dog out of'operative working :posi- 9. In a topfeed mechanism for sewing machines, the combination with a frame in-' cluding a horizontal work support and a head disposed above the same, of a feed bar including a feed dog carried by'the head for feeding the work rearwardly between the work'support andthe head, said feed dog having its workengaging'surface disposed in a vertical plane, a lever fulcrumed on the head and having pivotal connection with the rear end of the feed ,bar for reciprocating said bar longitudinally in the line of feed, and a lever fulcrumed on the headand having a sliding connection'with thefront end of the feed for reciprocating saidbar in a plane at substantially right angles to its longitudi V nal axis.

10. In a top feed mechanism for sewing head and having its lower end pivotally connected to the rear end of the feed bar for reciprocating said bar longitudinally in the line of feed, a link connecting the eccentric and the upper end of-the lever, alever ful crumed on the head and having a sliding con-' nection with the front end of the feed bar for reciprocating said bar'in a plane at substantially right angles to its longitudinal axis, and operating connections between said shaft and said second lever. Y

11. In a top feed mechanism for sewing 'machines, the combination with a frame including a horizontal work support and a head disposed above the same, of a feed bar including a feed dog carried by the head for feeding the work rearwardly between the worksupport and the head, said feed dog having its work engaging surface disposed in a vertical plane, a rotary shaft journaled in said head, an eccentric on said'shaft, a vertically disposed lever fulcrumed on the head and having its lower end pivotally connected to the rear end of the feed bar for reciprocating said bar longitudinally'in the'line of feed, a link connecting the eccentric and the 5 upper end-of the lever, a lever fulcrume'd on s the head and having a sliding connection with the front end of the, feedbar for reciprocating saidbar in a plane at substantially right angles to its longitudinal axis, and operating connections between said shaft and said second lever including a counter shaft, a pcripheral cam fixed on said counter shaft and having direct contact with said secondlever, and a-spring connecting the second lever and head for maintaining said contact between thelever and cam. f

12. In altop feed mechanism for sewing machines, the combination with a frame including a horizontal work support and head disposed above the same, of a feed bar including a feed dog carried by the head for feeding the work rearwardly between the work support and the head, said feed dog having its work engagingsurface disposed in a vertical, plane, a lever Vfulcrurne'd on the head and having pivotal connection with the feed bar for reciprocating said bar longi rock shaft, a spring connection between the head and the rock shaft for yieldably retaining the shaft against rocking movement, a lever fulcrumed on said crank pin and having connection with the feed bar for reciprocating the bar in a plane at substantially right angles to its longitudinal axis, means for oscillating said lever, and means for oscillating said rock shaft against the tension of said yieldable means to shift the fulcrum of the lever for moving the feed dog out of operative working position.

13. In a feed mechanism for sewing machines, the combination with a work support, of a presser foot having a vertical guideway extending rearwardly from its front end, an oscillatory needle movable across the guideway, one wall of the guideway extending in rear of the path of needle oscillation, a four motion bottom feed cooperating with the presser foot to feed the material along the guideway past the path of needle oscillation and including a feed dog having its teeth in a horizontal plane, and a four motion top feed cooperating with the rear wall of the guideway to feed the seamed material rearwardly away from the path of needle oscillation, and including a feed dog having its teeth in a vertical plane.

In testimony whereof I hereunto affix my signature.

CHARLES W. MUELLER.

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