US2627239A

US2627239A - Attachment for making stitched hems

Info

Publication number: US2627239A
Application number: US9678A
Authority: US
Inventors: John P Enos
Original assignee: Singer Co
Current assignee: Singer Co
Priority date: 1948-02-20
Filing date: 1948-02-20
Publication date: 1953-02-03
Anticipated expiration: 1970-02-03
Also published as: US2598638A; DE856824C; AT171049B

Description

Feb. 3, 1953 J. P. ENOS ATTACHMENT FOR MAKING STITCHED HEMS Filed Feb. 2o, 1948 Feb. 3, 1953 J. P. s-:Nos 2,627,239

ATTACHMENT FOR MAKING STITCHED HEMS Filed Feb. 2o, 194s 2 SHEETS- SHEET 2 55 291WL d 5@ al lwwmko@ Jahn Z? Enos material,

`body material.

be visible at the outside thereof.

Patented Feb. 3, 1953 UNITED STATES PATENT OFFICE 9 Claims.

This invention relates vto means for making stitched hems in sheet material.

`One of the objects 'of this invention is toldevise improved means for `forming and stitching a hem by a `conventional straightaway 'sewingv machine, in which the stitches,-i.vhich attach-.the hem to the body material, will be either completely hidden at `the faceof the work or will appear only inconspcuously/at widely spaced inter- `vals; dependentupon the thickness of lthe material.

Another object of the invention is to provide `an 'improved attachment i for a conventional chinecyclically to make a predetermined number of straightaway stitches in one plyof ahem fold, which stitches are completely hidden atthe A'front of thework, and then to *make a, single offset `stitch which partially or completely` penetrates the body material, theoiset stitches attaching the hem fold tothe body material -at `widely spaced intervals. In materials which are reasonably thick, the spaced hem-attaching-stitches.may

enter and emerge from the same side ofthe `body 4without passing therethrough, "fand therefore will be invisible on the outside of 'the In other materials, which are too thin for the 'needle to split, the hem-attaching stitches may pass through the body material and However, t as these stitches are small andV are spaced apart a considerable distan-ce, for example, about one inch, they are inconspicuous and'resemble hand sewing.

Thisinvention has been embodied in anattachment which is"basically vsimilar to the zig-'zag vattachment which forms the subject'of United States Patent No. 2,175,293, October 10, 1939, of G. L. Hinman. The present attachment,how ever, contains features not included inthe Hinman construction and which adapt theA attachment for performing blind-stitch hemming as above described, instead of continuous zig-zag stitching for which' the Hinman device was designed.

2 With the above and other `Objects in View; yas `will hereinafter appear, the invention comprises the herein described devices, combinations, and

i arrangements of parts hereinafter'set forth and illustrated `in the accompanying.drawingslof a preferred embodiment of the invention, lfrom which the several features of the inventionrand the advantages attained thereby-will be readily understood `by those skilled inthe art.

In the drawings,

Figfl `is a side elevation-offmyimprovedattachment `showing it secured tothe pressure-bar of a conventional family-sewing machine andfactuated by the reciprocating needlebar thereof.

i Fig. 2Ais a viewsimilar to Fig.1 but looking` in the opposite direction and with anfactuating stud, carried by the needle-bar, shown insection.

Fie. 3 is a horizontalsectional view taken sub- -stantially'on the line 33 of Figure 2.

Fig. 41s a vertical sectional viewtakensubstantially on the lined-4 or Fig. 2.

Fig. 5 is an enlarged transverse sectional view taken substantially on the line 5 5 of Fig. `3,110- gether with a` portion of the throat-plate ofthe machine lshown in section.

Figs. 6, land 8 `are detail vertical sectional views, with theparts in various positions, of a shiftable Work-holderand means for shifting it laterally at predetermined times, form-ingvpa-rts of my improved attachment.

Fig. 9 is a horizontal sectional view taken substantially on the line 9--9 of Fig. 6,1bu-t with the parts shown in full lines `in the #position illustrated in Fig. '7.

Fig. 10 `isan under side view of a workhclding and shifting member, laterto be described,tand parts closely associated therewith.

Fig. 1l isv a` perspective View representing a workpiece :havinga `hem which has been blind stitched by use of a sewing .machine ttedlwith i my improved attachment, the lower portion of the 1 figure showing the workpiece as `it :is folded =and stitched, and the upper fportion of the` 'figure showing'the body portioniof the workpiece turned over to the right to expose the outer surface of the hemmed workpiece,

'Referring lmore `speciiicallyto thedrawings. i the structural 'characteristics `of the invention are disclosed as embodied in an `'attachment'. comprising a main frame member havingaverticallydisposed plate I0 Vwhichwhasfat its `lower edge, a horizontally extending `flange ll` `connected tothe yplate ID at its `front and rear ends, there `being a slotwor opening `I2 between theplate `and the `ange for the greater part-of the length of `the latter between the two fpoints of connection. `In

adjusted positions.

termediate its ends, the slot I2 has an upwardly extending portion I2EL (Fig. l) through which extends a spring hereinafter t be described. At its forward end the portion II] is provided with a shank portion I3, generally U-shaped in horizontal cross section, adapted to be secured upon the lower end of a presser-bar b of a sewing machine by a clamp-screw c, in place of the usual presser-foot. The sewing machine, of which the presser-bar forms a part, also includes a conventional work-feeding mechanism designated generally as f, which operates through a slotted throat-plate p, and stitch-forming mechanism including a reciprocating needle-bar 9, carrying, at its lower end, an eye-pointed thread-carrying needle n which cooperates with a conventional loop-taker mechanism, not shown.

Pivotally mounted on a stud I4, secured in an upwardly and rearwardly extending arm I5 of the plate I0, is a bell-crank actuating lever I6, having a relatively long forwardly extending arm I'I and a relatively short downwardly extending arm I8. The arm I'I is formed with a forked forward end I9 which straddles a stud 23 carried by the needle-bar 9. The arm I8 of the lever I6 has, at its lower end, a transverse portion I8a from which project lugs I8lo and ISC. Threaded through the lug I3c is a screw 2I having a rounded free end 22, a collar 23 and a knurled head 24. The screw 2l is embraced, between the shoulder 22 and the head 24 by the offset arcuately shaped end 25a of a flat spring 25 which is secured to the portion I8a of the arm I8 by rivets 26. The spring is tensioned to frictionally engage the screw 2| by means of its curved end 25a and thus holds the screw in its From the foregoing it will be understood that reciprocatory movements of the needle-bar 9 are translated into oscillatory motions in the actuating lever I6. During such oscillatory motions of the lever I6, the lug IBb and the rounded end 22 of the adjustable screw V2I are successively brought into contact with the upper free end Zia of a lever 21 fulcrumed on a stud 28 carried by the plate Ill, thereby oscillating that lever for a purpose hereinafter to be described. Inasrnuch as the lever I6 has a fixed range of movement, the amount of movement transmitted to the lever 21 will be determined by the setting of the screw 2l, adjustment of which varies the amount of lost motion between the end 2'IEL of the lever and the lug I8b and the end 22 of the screw 2 I. Y

Pivotally mounted on the upper surface of the forward end of the flange II by a stud 29 is the horizontally disposed shank 30 of a work-holding and shifting element 3I, in the nature of a presser-foot. Hereinafter, this element will be referred to as a work-holder. The under surface of the work-holder is serrated, as shown at 32, in Figs. 5 and l0, to cause it to grip the work and shift it laterally when the element is shifted transversely of the line of feed as hereinafter explained. The work-holder is formed with a rearwardly extending portion 33 (See Figs. l, 2,

' 9 and 10) having fiat surfaces 33a and 33b adapted to abut the forward end IIEL of the plate II to limit the lateral movements of the work-holder. The work-holder is normally yieldingly maintained in the position shown in Fig. 3 and in dotwardly extending leg having an offset portion 3lIb which bears against the right side of the workengaging foot portion of the work-holder 3 I. The work-holder is formed with spaced upturned toe portions 3Ia, 3lb and a transverse needle slot 36. Adjustably secured upon the upper side of the work-holder 3I, by a screw 3l, is the shank 38a of a spring steel edge-guide 38 having a downturned edge-guiding portion 38h (Fig. 5). The member 38 carries, at its under side a block 39 which, as shown most clearly in Fig. 5, bears upon the folded marginal portion 'm of the workpiece w while the portion 381 is guiding the so-called fold-edge e thereof, al1 hereinafter described.

Oscillation of the levers I6 and 2'! from the needle-bar effect periodic lateral shifting of the work-holder 3l and the workpiece w therebeneath, as now will be described. Pivotally connected to the lever 2l, at 39a and Ma, are upper and lower slide-bars 43 and 4I, respectively. These bars are urged tow-ard each other by the action of a spring 5I having its mid-portion secured behind the head of the stud 28 and its crossed legs 5Ia and 5Ib engaging respectively the slide-bars 40 and lll. The oset bar-engaging portion of the spring leg 5 Ia extends through the slot I2a in the plate Il). The slide-bar 43 is heldV against the rear face of the plate I3 and guided during its sliding movements by a guide member 52 secured to the rear side of the plate as by a rivet 53 (Fig. 2). When the lever 2l' is oscillated, the slidebars lll) and lll are reciprocated simultaneously in opposite directions. In nine stitches of each tenstitch cycle these reciprocations are idle movements and perform no function, the machine sewing straightaway stitches. ing of the tenth stitch the backward movement of the bar 4I and the next forward movement of the bar 49 shift the work-holder 3|, and the work therebeneath, first to -the right, as viewed from the front of the machine, and then to the left. This lateral movement of the work, relative to the stitch forming mechanism, causes the machine to make a stitch transversely of the main line of straightaway stitches as hereinafter will be described.

The slide-bars 40 and 4I are provided `at their adjacent edges, respectively, with straight surfaces b, Mb, rear recesses or notches 43C, Mc and forward-recesses or notches 49d, Md. The forward wall lle of the notch Qld isinclined upwardly and rearwardly and is adapted, at certain times, to engage the upwardly and rearwardly inclined forward edge 35b (see Figs. 7 Vand 9) of a transverse portion 399 of the shank 33 of the work-holder 3l. When the work-holder is so engaged by the slide-bar 4I rearward movement of the bar swings the work-holder about its pivot 29 from the position shown in dotted lines in Fig. 9 to the position shown in full lines. During the next forward movement of the slide-bar 49 the upwardly and rearwardly inclined wall 49e of the notch 49d engages the inclined rear edge 3l)c of the portion 30a and turns the work-holder 33-3I about its pivot 29 from the position shown in full lines in Fig. 9 to the position indicated in dotted lines, thereby shifting the workpiece therebeneath back to its original position.

During the making of the first nine Vstitches of each ten-stitch cycle the slide-bars 4G and il are held out of engagement with the transverse portion 32a of the shank of the workholder. Therefore, during that period the bars are reciprocated but have no effect on the workholder 3|. The holding of the bars Il()V and 4I During the mak-V away stitches.

out "of-engagement with theyLpor-tionS302*v `ifi-efifected by=a rotaryccontrolf elementi-42 inthe form of a rectangular block having -rounded ends.

AAsy shown most clearly in Fig.` 4, this control element Q2 is carriedby` a stud=43 journaled in ahub im forming apartof-a bracket 45 secured by screws i6 to Aonesideof the `plata-lli.

`Secured upon the control-element, coalxial with the `stud 53 is aatwenty tooth `ratchet wheel c di adapted -to -ibe i engaged and shifted, one tooth `ata time, `by an actuating pawl 48 journaled upon the -pivot piniial ywhich pivotally connects the slide-barret with-thevlever 2.7!. Acoil` spring 49, sur-rounding the pivot-pinidafhas an in- `turned `limb Mia connected `to `the `pivot pin `and alaterally extending limb 491 -Which lbears upon the' pawl to hold -it in contact i with-the ratchet wheel. A retaining pac/i556,-the-shankliie vof -whichwis secured to the side 4of the bracket -45 by the screws 16, has ai depending fingern-5tb lying` against .the side of` the bracket 4145 i and engaging the `teeth ofthe ratchet wheel -to prevent retrograde movement `of the wheel.

As hereinbefore stated reciprocation` of the needle-bar feiieots, -through the -lever- Iyoscillatory `movements of thelever 21 and reciprocatory motions of the slide-bars A0, 4I. During such-movements the pawl 48 iswadvancedV and retracted, thereby transmitting to the ratchet wheel step-by-step `rotary `motions `equal in `length to the angularspacing of the teeth of the wheel. This intermittent rotation of the ratchet wheel eiectsi-rsimilar step-by-step rota.- tion -of Vthe controlmember or block it?, Athe rounded i ends of vwhich Aare adapted to engage the opposed surfaces Mib; llbof the slide-bars fii,A M, thereby to separate the bars in opposition tothe influence-oi the spring 5L In `the position shown in Fig. 7, the block 42 -is arranged parallel .with the surfacesr-i-iib, `all and-therefore the slide-bars are moved toward each other by the spring E! until 4they engage thef portion 3de of the shank of the Work-holder. With the parts in this position,` the next retractive movement of -theslide-baridl willshift thework-holder from the lposition shown in `dotted lines -in` 9 to the position shown `in` full lines. These lateral movements of the work-holder-and the `work therebeneath `causes the machine to make a stitch to one side of the normal l-ine of straight- During the nextsucceeding forward movement of-the slide-hariw, Vit will engage the rear `edge of the portion 3de and shift the .work-holder back tothe position 'shown in dotted lines in Fig. 9. During the next nine reciprocations of the needle, the roundedV ends of the controi block Q2 engage the surface-s lith and Hb of the slide-bars and hold them apart, in opposition -to the spring 5I (see Fig. 6), so that the slide-bars reciprocatewithout engaging 'the shank of the work-holder, which therefore remains in the position shown in Fig. 2 and in dotted lines in Fig. 9. While the slide-bars are held out of contact with the portion 56a, the sewing machine forms a line of nine straightaway stitches. This cycle is repeated during each half turn of the ratchet wheel or, in other words, once for each ten stitches.

Referring to Fig. 5 and the lower portion of Fig. l1, it will he` understood that to perform the blind-stitch hemming operation the workpiece w is folded into a ilat Z-shape, comprising plies I, 2 and 3, and placed beneath the workholder 3l with themarginal portion m beneath A'the-block '39 and thewfold-edge e against the CII `-side fof i the` edge-guiding portion t38bi1of :the edge-guide 138. `be unfolded or "it may .be -iolded back touplace The marginal 1 portion .may

the edge portion m thereof between theqplies i l and 2,-asfshoW-n in `liigs. 5'and 1.1. VThe Worlepiece thus folded` and .guided is Mfed. to `and .past

i the stitching mechanism Ywhich lcyclically .pro-

`cluces a line "of straightaway stitches s 'through the marginal portion :m f(folded .or 'unfolded) closely :adjacent .the iold-edgefe,ia11d, at :every tenth reciprocation Vofwthe needle,a..lateralfior transverse stitch t `which passes;y .throughilthe fold-edge e 'and Athe marginal portion m,:.there `by anchoring :the fold-edge lto .the Lmarginal zportion at spaced intervals. .At .the completion of lthe hemming operation thexworlrpieceiszopened out,` as indicated at the .upper portionof` 11,

to place lthe `blind-stitch` Vhenri at the reanace `ont the workpiece.

:.E `adapted to be swung `horizontally .through the slot vI2 in the plate .It .to a positionzin which it lies` between the slide-bars .iidlraand -holds those bars out .ofwengagement with the cross-barsta of the `shank ofxthevwork-holder, as described more fully -in the Aalcove. `mentioned HinmanV Patent No. 2,175,293.

Having thus set forth lthe nature of the .invention, what I claim herein is:

1. A hemming attachmentforra :sewingwmachine having a reciprocating.needle-baranda needle carried thereby, comprising a frame; `a Work-holder connected to the frame` for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder; an edge-guide carried by said Work-holder for guiding a folded edge of theworlr relative to the line of reciprocation'of the needle with a .marginal portion of the work projecting beneath the edge guide and `beyond the `fold of the work guided by the edge-guide; automatic means actuated by the needle-bar for laterally shifting the workholder, the edge-guide and the Work relative to the line of reciprocation of the needle to cause the machine to make laterally offset stitches through the folded edge of the work; andautomatic `means periodicallyrendering the workholder shifting means ineiective during the formation of a plurality of stitches thereby to `cause the machine to form a series of straightportion of the workprojecting beneath the edge-` guide and beyond the fold of the work guided by the edge-guide; automatic means -for eiiecting lateral shifting of the Work-holder, the edgeguide and the work relative to the line of reciprocation oi the needle; and meansactuated by the needle-'bar for rendering the 'work-holder shifting rsaeavgaee 7 means effective and ineffective in a predetermined cycle to cause the machine to sew a plurality of series of straightaway stitches through the projecting marginal portion of the work to one side of said folded edge separated by a lateral stitch formed through said folded edge.

3. A hemming attachment for sewing machines comprising a frame; a work-holder connected to the frame for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder; a lever fulcrumed on said frame and having one end operatively connected to the needle-bar of the sewing machine for oscillation thereby; a pair of slide-bars carried by said frame and reciprocated by said lever; operative connections between said slide-bars and said workholder for shifting the work-holder in opposite directions by the reciprocatory movements of said slide-bars; and means actuated by said lever for periodically rendering said slide-bars effective and inelfective to shift said work-holder.

4. A hemming attachment for sewing machines Y comprising a frame; a work-holder connected to the frame for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the Work-holder; a lever fulcrumed on said frame and having one end operatively connected to the needle-bar of the sewing machine for oscillation thereby; a pair of slide-bars carried by said frame and reciprocated simultaneously in opposite directions by said lever; shoulders on said slidebars adapted to engage said work-holder to shift it in opposite directions to cause the work to be shifted back and forth laterally of the line of seam formation; means for holding said slidebars out of engagement with said work-holder during the formation of a plurality of straightaway stitchesand means actuated by said lever for periodically permitting said slide-bars to engage and shift said work-holder laterally after a plurality of straightaway stitches have been formed, thereby to cause the machine to make an offset stitch.

5. A hemming attachment for sewing machines comprising a frame; a work-holder connected to the frame for back and forth shifting movements inV a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder.; a pair of slide-bars carried by said frame and actuated from the needle-bar of the sewing machine and designed to engage said work-holder for effecting lateral shifting of the work-holder and the work therebeneath relative to the line of reciprocation of the needle;a control element engaging said slide-bars to hold them out of engagement with said work-holder during a plurality of reciprocations of the needle-bar; and means actuated by the needle-bar for shifting'said control element into a position in which lt permits said slide-bars to engage and shift the work-holder, and the work carried thereby, laterally during one reciprocation of the needle-bar.

6. A hemming attachment for sewing machines comprising a frame; a work-holder connected to the frame for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder; a pair of spaced, spring-biased sli-debars carried by said frame and actuated from the needle-bar of the sewing machine and normally and the work therebeneath' relative to the line of reciprocation'of the needle; a. control member located between said slide-bars and holding said slide-bars out of engagement with said workholder during a plurality of reciprocations of said needle-bar, whereupon a plurality of straightaway stitches are made by the sewing machine; and a ratchet device actuated from said needlebar for shifting said control-bar for shifting said control member to a position in which it permits said slide-bars to engage and shift the Workholder, and the work carried thereby, laterally after said plurality of straightaway stitches have been made, thereby to permit said slide-bars to shift said work-holder and work laterally.

7. A hemming attachment for sewing machines as set forth in claim 6, in which the ratchet device includes a ratchet wheel carried by the frame of the attachment and an actuating pawl therefor which is shifted by the movements of the needle-bar; and in which the control member comprises a stud which projects coaxially from and rotates with said ratchet Wheel and lies between said spring-biased slide-bars, said control member having major and minor diametrical dimensions and acting in all positions, except when its minor diametrical dimension separates said spring-biased slide-bars, to hold said slide-bars out of engagement with said work-holder.

8. A hemming attachment for a sewing machine having a reciprocating needle-bar and a needle carried thereby, comprising a frame, a work-holder connected to the frame for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder, an edgeguide for guiding a folded edge of the work relative to the line of reciprocation of the needle with a marginal portion of the work projecting beyond the fold of the work guided by said edgeguide, a lever pivotally carried bythe frame for automatic oscillation by the needle-bar of the sewing machine, means for normally maintaining the work-holder in a fixed predetermined position during a series of oscillations of the lever whereby to cause the machine to form a series of straightaway stitches in the projecting marginal portion of the work, and means actuated by said lever for periodically shifting the workholder and the work therebeneath transversely of the frame to cause the machine to make transversely offset stitches through the folded edge of the work between successive series of straightaway stitches in said marginal portion.

9. A hemming attachment for a sewing machine having a reciprocating needle-bar and a needle carried thereby, comprising a frame, a work-holder connected to the frame for back and forth shifting movements in a horizontal plane in a direction generally transverse to the feed of the work beneath the work-holder, an edge-guide for guiding a folded edge of the work relative to the line of reciprocation of the needle with a marginal portion of the work projecting beyond the fold of the work guided by said edge-guide, a lever pivotally carried by the frame for automatic oscillation by the needle-bar of the sewing machine, means including a spring biased against said work-holder for normally maintaining the latter in a xed predetermined Yposition during a series of oscillations of the lever whereby to cause the machine to form a series of straightaway stitches in the projecting marginal portion of the work, and means actuated by said lever for periodically shifting the work-holder and the Work therebetween transversely of the frame V,to

cause the machine to make transversely oiset stitches through the edge fold between successive series of straightaway stitches.

JOHN P. ENOS.

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

Number