US2562009A - Reverse stitch attachment for sewing machines - Google Patents

Description

July 24, '1951 R L. ABos ETAL REVERSE STITCH ATTACHMENT FOR SEWING MACHINES Filed March 26, 1948 Patented .ul'y 24, i951 y2.562mg REVERSE STITCH ATTACHMENT'FO I SEWING MACHINES Ralph L. Abos, Laurence M. Stanfield, and Robert B. Myers, Los Angeles, Calif., assignors to Revco Products, Whittier, Calif., a corporation of California Application March 26, 1948, Serial No. 17,264

22 Claims.,

This invention relates to sewing machines, and more particularly it relates to attachments for sewing machine heads of old models for adapting them to perform new functions.

One object of the invention is to provide an easily operable attachment for certain models of household sewing machines whereby they may be converted into what is known as the reverse stitch type, and whereby stitching either backward or forward may be accomplished at the will of the operator. f

Another object of the invention is to provide an' attachment of the indicated nature which will serve merely as a replacement of a portion of the stitch controlling mechanism of the original machine.

yStill another object of the invention is to provide a reverse stitch attachment which will be wholly enclosed within the original machine head except for a manipulating knob projecting from the front of the head.

It is a still further object to provide a reverse stitch attachment which may be quickly installed to replace the original stitch regulating mechanism and without the necessity for modifying any of the retained original equipment. f

In order better to explain the general purposeof our invention, it is pointed out that some of the old model sewing machines, that is, those which are equipped only with the old style conventional backward feed mechanismvby vmeansy of which the material is fed away from the oper--V ator, use a vertical connecting rodr which is known in the trade as a feed fork connection. connecting rod is used to actuate a rocker arm which causes a serrated feeder mounted in the base of the machine to be moved back and forth along the stitch line under the fabric being stitched for intermittently feeding the fabric rearward. A cam mechanism, which is used in conjunction with a shuttle actuating device, serves to raise the feeder into operating position during` this rearward travel and to lower it out of operating position during its forward travel. Another cam at the opposite side of the sewing machine head acts to oscillate the upper end of the connecting rod or feed fork connection, and during such oscillation such rod is cyclically raised and lowered through the medium of a guide roller which it carries and which travels in an inclined adjustable channel-shaped guide mounted upon an adjacent stationary portion of the machine head. Varying the tilt of the guide upon` the pivot by which it is carried` serves to increase or reduce the throw of the connecting rod and the stroke of the feed dog and thereby lengthen or shorten the stitch. In connection with the present improvement, this guide is mounted so that it may be rocked about its pivot to tip it to one side or the other side of the pivot, i. e., either 2 l '.j, rearward or forward, whereby thev movement off' the feed dog may be correspondingly reversed and as a consequence the direction of the stitching"l will be reversed. When the guide is in a neutral or horizontal position, no stitch isy produced, but

as the guide is tippedl in either direction to al greater or smaller degree, the stitch in a corre# sponding direction becomes accordingly longer; or shorter.

However, sincey it'is normally desired to main#` tain a stitch of constant length, it is desirablef that any reverse stitch mechanism be such that, the length of stitch be exactly the same 'when reversed as it was before reversal. l 7

It is, therefore, also an object of this invention'f to employ reverse stitch mechanism which willi act, not only to tip the guide so that the stitch; may be reversed, but will also automatically `pro-1 vide for stitches of exactly equa1 length in the` opposite directions when reverse stitching is beingf accomplished. ,i

Additionally, it is an object of the invention to, provide a reverse stitch mechanism by means of.I which lthe operator may hold the parts in reverse, stitching position as long as required, the parts; automatically returning to conventional stitching; position upon release of the mechanism by they operator, that is, so that the fabric is fed back-l: ward. i '1.

It is a furtherobject to providel in a reversev stitch attachment means for maintaining the stitch-length adjustment against unintentional change during stitch-reversing operations. l

Other objects and features of the invention will appear to those skilled in this art upon refer-' ence to the following specification and the accom-51 panying drawing wherein certain embodiments are disclosed for the purpose of illustration.

In the drawing: i

Fig. 1 is a side elevation of a conventional old` style sewing machine head indicating applicationfof an attachment of the present invention Vthereto for the purposev of adapting the machine to re-L verse stitch operations; 'l Fig. 2 isy a vertical cross sectiontaken on the; 1ine2-2ofFig.1; Fig. Bis an enlarged detail showing the channel guide in end elevation and showing the relation; ship of an offsetting adapter and the guide roller'j carried thereby with respect to the channel guideand the actuating means therefor', *511 Y' Fig. 4 is a longitudinal section onI n enlarged scale viewed in the directioncf'Figp;. i ff'f f Fig. 5 is a side elevation lshowing therecipro cable shaft of Fig. 4 rotated about 180; Fig. 6 is a cross section .takenfon the line-f6 ofFig.4; Fig. 7 is a fragmentary detail 'of a triangular; grove provided` in the 4reciprocating,shaftgfor;

In Figs. 1 and 2 there is disclosed a conventional sewing machine head l 'which in the table I6.

I1 and pulley I8 driven by a belt -I9 are shown affixed to a conventional drive `shaft 26. ywhichy is provided with various eccentrics or cam mechanisms, one of which reciprocates a needle bar 2| carrying a needle 22, the bar 2l being "located in the adjacent portion of the head l5 'which supports a conventional 'presser foot 23 above a slot 24 in the Work table I6.

,fIhe shaftZO carries an eccentric 25 which oscillates a fork or Abifurcation I26 of a connecting xfodvZwotherwise known as a feed fork connection. AThe lower end of the rod 28 is .pivoted and supported at 29 upon a short arm 30 on a rock shaft 3| located below` the work table IB. At the left end of the shaft 3l, as'shown in Fig. 1, and at a pointa'dj'a'centthe needle bar "2 l, the upper side of the shaft 3l is provided with'upstanding arms '32 which are pivo't'a'lly connected t'o'a yoke 33, one 'branch of which extends rearward iinderth'e'table 'l''and carries on the upper side vat'its 'rear "end'a usual feed'dog 34 comprising a plurality of/fee'd teeth 'whichnormally project'up' throughjthe's'lot 24 inthe 'work table to feed fabric heldin engagement 'therewith by means of the presser `'foot 23 :when the llatter has been placed in lowered position by'well known means. 'The other ybranch "of the l'yoke 33 carrie's'fa -pin orrolle'r35- Fig.-2) which engages-in a cam groove of a cam 36 operated 'from the drive-shaft''ZlJ in conjunction with a shuttle-in a wllknownnianner-'by means not shown. The cam l36 is transversely reciprocated with-respect toth'e Ashowing oflFig. 2 -so thatltlre'feeddog'll is raised in the conventional'manner vthrough the" slot '24# into fabric f engaging :position-'as the feed dog ismovedlrearward by the yyokef.33, the feed dog being drawn down below the work `table |6.,by==the eam=36during movement of the-'feed dog forward. I

s :The Iattach-ment' mcorpQra-.tng :the present in.- vention makes it; possible l for the effective movements .of the-feed dogq34 with respect -fto .the movement -of the- cam 3,6 Ito `be reversed at twill, so that the feed dogmay be caused to `move forward in reversevstitch relationship `whenthe cam 36 raises it Vup 4into fabric engaging-position,

the feed dogbeing then drawn down nbelow the table l lli by the cam :.tovdisengage the `fabricl as the Yoke 33 lprepares to 'drive the feed dog '.34 rearward, the length of the stitch to be the sarne nbofth directions. l'This normal' vertical'move ment'of the connecting ro'd'ZB'- to effect the described movements of the "rck Shaft "3|, the ykeaa. and' the feed dcgsa is effected through theA medium of a guide roller 48 pivotally mounted on" the' rod 28 and 'operating in'ia channel' 4I' (Fig. 4 ),'in one side of a tiltable channelzguidei42 pivotally` mounted on'the head I"5"by a bearingi43 and' by 'being'ied' upon a shaft 44 rotatable 'in the bearing 43. n

Inf conventional'construction' and practice, the

guide roller 40v pivotally mounted on vthe con-v aperture and being also on the center line cf--the` Shaft'f44vwhenthe channel guide 42 is in its zero Stitch position.

-'I-Iowever, this conventional mounting provides for tipping cf the channel guide to one side only, andjhencelperrnits stitching in one direction only. In connection with the .present invention, an adapter is required for the purpose of mounting the roller 40 on an axis lsen-iewhat out of alignment with the axis of the Iaperture 28a.

This adapter comprises an offset centering guide pin y46 which directly carries the roller 4U and is xedly supported by an oisetting plate 48 which in :turn is xedly carried on an anchoring shank 50 secured in the aperture 28a of the connecting y.rod 28. A convenient means lfor mounting the adapter in the aperture 28a is thatindicated by threading the outer end of the shank 5U as shown and'femploying a nut 52 for binding the voffsetting plate 4B .against the .opposite face-.of the connecting rod 28. .Theplate 4,3 also serves as a. :thrust bearing f-Or t e roller 4,9 which in turn causes` Athe plate 48 to clear ,the ed'gevof the-channel guidev42`. l v y f v The extent .of the offset between the @entering pin 46 .and the vanchoring sha-nk .iisfsvfh @5&9 align the center 0f the roller with the (center 0f `the channel .guide 42, which .is on ,the axis -of the Shaft 4,4 when these Darts' are middle or neutral positions. In practice,"

, exact distance andfangleimay -varylighily amount of the offset between ,C t rsiissxjnell. beine approximately;Onefesllth A@Tf an 111.19211 @1.14, the centering pin 46 is Adisguised ,at an angleci.y about-15 upward v@metothe left With lpet. Y the shank 50, as the parts are Viewed in g a. Desired relatnships .between `all ef, the @et tme mechanisms vfor kthe .feeddggian the Smidt regulating mechanism are thus obtained. ,-The,

' diierent models.

`Since .the direction of movement :of the feed dog r34 through :the v4.feedingv portion vof path is governedl by fthe 4direction vci? v. inlinaticn of the channel guide v472, and since 4the length-9i Stitch in either :direction 11S governed .by fthe da, aree Qfinclinauon of thethannel guid??? inthe respective direction. the latter Serves beth-.asn feed regulator and as a Stitch reverser.- "lhe p9: Sition of the ,channel guide 42 `with respect t0 the adjacent face-0f the connectinecd :2.8 is um tained by ftheShaI-t 1.4 which inturn is main:- tained' in therheadlies-through the medium'f an integral f head bilV bearing against 'an appro.- nriate :spring Washer .55 whicnlmay'bme conviene ient1y= disposed fin .a ecou-ntersink 56.. ,Selectiqn of 4.the direction 'and degree of :inclination of the Q hannel.. guide -'-.42, and Aconsequently iselectionrifi thezidi-rectionzof v stitch andof the: length of :stitch is'easfly accomplishedby:partial rotationlof the channelfguide 42v and itsshaftM :against Lthexten:` sion lof Sthe'spring .washer 155 through the :me-- diumy v. of :an .rupstanding f nger 158 ..under control of the stitch.` reverse=mechanjsmof this i-nvention Iwhich fis generally indicatedatl. In .order thatithe'ngerl'B Lmay actuatethe channelguide 4 2, .the upper-.end of the finger. isf provided .ewitna .balli-type: headll I which extends intoa .socken-82' int-he underside-ofthe )lower flange Ma-'of Athe channel guide 42 below `the channel 14|, as'fbest illustrated in 1'l-igs.-4 and -5. iThe -headflil-is urged' intofsealing position inthe socketl62 through-the medium. of LaA springf63 disposed: about 'the nger 58; the upper end -of the spr-i-ng'l53 bearing againstr an annular collar64 onthe pinl 68'-be1owthe head 61. eA-t least '-fthe Ylowerflange 42a is-preferably1 for-medon the -arc'lof a circle wherebyhtof'avoi'd' any* possible 1 interference of Athe annular collar' lidiiwth thelmovement of-*lthe'lowerl'langei42aetoi extremeltilted-positions. The lower end of the' .i .l Operation f vWhen the stitch reversing'mechanisin o f this invention is assembled as illustrated Figs and placed in operative position as indicated'in Fig. 2, the coil spring Vto projects the shaft 1li, the vbarrel S and the up'staiidiri'gl 'nger '58 iii-'- ward to the limit of movement determined by the position of the triangular groove 83 so that'1 if `the ball detent 82 is not held in a neutral ipo-- 'siltiorl by 'the point '84 of the groove B3, the

channel guide V112 is tipped in adirection opposite to that indicated in iig. 4, thev inner 'end oi the skirt 99er the knob-12 rying near the annular flange r88 of the sleeve 15. Under these condi'- tions the .threads e of the sleeve 15 are bound in the corresponding threads of 'the casting l5, and the nut 9| and the iian'ge 88 .serve 'as lock nuts for each other. By pulling the knobl 'I2 outwardand holding it manually in such position against the spring 88, the stitching is reversed. Upon release of the knob, the spring to returns and holds the .parts in normal or for- Ward stitching relationship. By rotating the knob T2, the shaft 'I8 is rotated to bring the triangular Ygroove 83 into any desiredposition of adjustment with respect to the ball detent a2 which is disposed in a .fixed position. As seen in Fig. 4, the ball detent 82 is disposed 'at the bottoni of the attachment, this relationship being 'also shown in Fig. 6. f the shaft l0 is rotated to the right, as viewed lin Fig. 6, vto the limit 'of its movement, the wide end of the triangular Agroove '83 is brought into alignment with the ball detent 82, the Vdetent 8 2 at this position coming into contact with the adjacent .portion of the elongated pin 95 .positioned in the longitudinally extending vgroove 84 at the surface of the portion 10a of the shaft 'IIL` With this relative relationship between the ball detent B2 'and the groove 83, pulling the knob 'l2 outward to withdraw the shaft T0, and return of the shaft 18 to its retracted position by means of the coil spring SUwill result in the maximum stroke of the shaft 10 andin consequent maximum rock of the channel Vguide v42. Such relative position of the groove 8 3 is indicated in Fig. 5.` In this position of the groove 83,'the length of stitch Will be the maximum both when the knob "l2 is drawn outward until the ball detent Y82 strikesthe rearward side sof.

the groove 83 on the path 8B, and when theshaft 10 is allowed to be returned to Athe opposite -position by the coil spring 80 when the ball detent 82 strikes the opposite side of the/groove '83 o'n the path as. The ydirection of stitch will be changed as rapidly as the knob 12 is moved be-` By rotating.

tween its two extreme positions. the shaft I0 to the left from the position of Fig. Stoward the position of Figs. 4 and 6, 'the friction joint at the 'cupped spring washer permitting such rotation, any intermediate position of the ball detent 82 with respect to the groove 83 may be had, such 'as that 'illustrated inV Fig'. '7. Under these circumstances 'the length of stitch in both directions will be 'cor'- respondingly reduced. By continuing rotation or the shaft 1o to the left, the rounded point; 84 of the groove 83 will be brought up about the ball deten't 82 at the neutral position of the shaft Y'Ill and its groove 83. no stitching whatever.

From the foregoing, it will be apparent that Here, there will be the shaft 10 and its triangular groove 83 Inay` be rotated through the knob 12 vto bring 'theL groove 83 into any position of rotational adjust` ment with respect to the ball detent 82 for. ythe purpose of accomplishing any stitch length ree quired, 'and -it will also be apparent that the di rection of stitch will be reversed as the shaft 10 Ais reciprocatecl through the medium of pull upon the knob lf2 and through the medium of the ree turning influence of the coil spring when the knob 12 is released by the operator. By making the sides of the triangular groove 83 symmetrical so that the .paths 85 and 86 for Contact of the ball detent are arranged symmetrically with respect to the corresponding Adiameter vof the lshaft .18., the length of the stitches. in the opposite 4'directions will be exactly the same for a .given setting. It will also be apparent from the foregoing that conversion from an old style sewing machine head providing for stitching in one direction only, as previously explained, may be quickly effe; fected merely by removing the old threaded mounting from the threaded aperture 16 ofthe sewing machine head i 5, removing the old ch'an'e. nel guide 42 and the mounting for its roller 48 and substituting the present channel guide 4Z and the adapter 45 to position the roller "48, and then mounting the stitch reversing 'mechanism 6D of this invention in the manner above 'de-'- scribed. f Inasmuch as variations of the generic invene tion herein disclosed will no doubt become 'ape` parent to those skilled in this art, it is intended to cover all such modifications `as fall within the scope of the claims.

We claim as our invention: 1. In combination in a reverse stitch attache ment for sewing machines: a shaft adapted to be rotatably and axially reciprocably mounted in a sewing machine head with its inner end adapted to be connected to a stitch control member to shift the latter; stop means adapted to be carried by said head; and engaging means `at an -intermediate position on said shaft to limit vmove-l ment. of said shaft in both of its reciprocating-- movements by engagement with said stop mozilla'I said 'enga-ging ymeans being adjustable with ire speels to said stop means for engagement with .said stop lmeans 'at a multiplicity of adjusted' positions in both reciprocating movements to; vary 'the amount of 'shift `of said control meme;

bert

' 2. n combination as in claim i wherein the adjustment of said engaging means is accome;

plislied by relative rotation of said shaft, the combination including means for releasably ree taining said Ishaft and its eng-aging means in itsv rotatably 'adjusted positions.

l"3. `Acom'lsiination as in claim 2 wherein 'said' engaging means comprises two opposed, "sy'm'e: metrically arranged members providing for eoual stitch lengths in opposite ldirections for each position of adjustment of said shaft.

said releasable retaining means.

A6. A combination as in claim '5 wherein saidj opposed 'divei'ging walls are provided by a V- shaped groove in the wall 'of vvsaid shaft, the :axis

ofv said Agroove being directed ciroumferentiall'jf' V around the shaft.

7. A combination as in claim 1 wherein said" engaging means comprises opposed diverging walls provided by a V-shaped groove formed around the wall of said shaft, said stop means being disposed between said walls of said groove.

8. A combination as in claim 1 wherein said engaging means is in the form of walls of a V- shaped groove cut in the surface of said shaft with the axis of the V-shaped groove directed circumferentially around the shaft, said stop means being disposed between said walls of said groove, and friction means providing for rotatably adjusting said shaft and its groove and for retaining said shaft in adjusted position.

9. A combination as in claim 1 wherein said engaging means comprises two opposed symmetrically arranged members providing for equal stitch lengths in opposite directions for each position of adjustment. n

10. A combination in a reverse stitch attachment for sewing machines: a sleeve having a bore, said sleeve being adapted to be -flxedly mounted in a sewing machine head in line with a stitch control member; reciprocating positioning means slidably mounted in the bore of said sleeve; detent means carried in said sleeve and projecting into said bore; diverging wall means provided on the surface of said shaft at opposite sides of said detent means and respectively adapted to engage said detent means as said shaft is reciprocated in said sleeve; and means for reciprocating and rotatably adjusting said shaft.

11. A combination as in claim 10 including means for maintaining adjustment of said shaft against accidental displacement.

12. In combination in a reverse stitch mechanism adapted for attachment to sewing machines: a sleeve member provided with a bore adapted to receive a reciprocating member, said sleeve being adapted to be mounted in a forward portion of the sewing machine head in a relatively fixed position; a member reciprocally and rotatably mounted in said sleeve member; means for rotatably and reciprocally moving said member mounted in said sleeve member; diverging wall means provided by one of said members in angular relationship with respect to the axis of said sleeve; detent means projecting from an adjacent wall of the other of said members in the position between said wall means for regulating and limiting the reciprocating movement; and means for preventing dislodgment of the respective members.

13. A combination according to claim 12 wherein said wall means are symmetrically arranged with respect to each other in opposing relationship whereby to insure stitch lengths which are equal in opposite directions.

14. A combination according to claim 13 including yielding means for preventing accidental disturbance of stitch adjustment.

15. A combination according to claim 14 including a spring control friction joint for maintaining said adjustment.

16. A combination according to claim 12 including means carried in a groove in one of said members and slidable axially with respect to said members to retain said detent means in operative relationship with respect to said wall means;

and knob means carried by said reciprocating member to confine said retaining means in operative relationship.

17. In a combination in a reverse stitch attachment for sewing machines: a shaft adapted to be reciprocally mounted in a sewing machine head with its inner end adapted to be connected to a stitch control member to shift the latter; stop means adapted to be carried by said head; engaging means at an intermediate position on said shaft to limit movement of said shaft in both of its reciprocating movements by engagement with said stop means; a radially projecting finger mounted on said inner end of said shaft; and a ball head on the outer end of said finger and adapted to seat in a corresponding socket in said stitch control member to rock the same upon an axis on which it is mounted.

18. A combination as in claim 1 including: a radially projecting finger mounted on said inner end of said shaft; and a ball head on the outer end of said finger and adapted to seat in a corresponding socket in said stitch control member to rock the same upon an axis on which it is mounted.

19. A combination as in claim 1 wherein said engaging means is in the form of symmetrically arranged walls of a V-shaped groove cut in the surface of said shaft with the axis of said groove directed circumferentially around the shaft.

20. A combination as in claim 1 wherein said engaging means comprises two opposed symmetrically arranged diverging walls provided on said shaft transversely to its axis and at opposite sides of said stop means, such walls providing for equal stitch lengths in opposite directions for each position of adjustment.

21. In combination in a reverse stitch attachment for sewing machines: a shaft to be movably mounted in a sewing machine head with an inner portion adapted for connection to a stitch control member to shift the latter; stop means adapted to be carried by said head; and engaging means provided on said shaft and in the form of side walls of a substantially symmetrically V-shaped groove cut in the surface of said shaft, the axis of said groove extending circumferentially around the shaft with said stop means disposed between said walls of said groove, said shaft and groove being adjustable with respect to said stop means for engagement of said stop means at a plurality of adjusted positions with respect to the walls of said groove.

22. A combination as in claim 21 including means providing for adjustment of said shaft and its groove and for retaining said shaft in adjusted position.

RALPH L. ABOS. LAURENCE' M. STANFIELD. ROBERT B. MYERS.

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

UNITED STATES PATENTS Number Name Date 1,118,271 Diehl et al Nov. 24, 1914 1,346,120 Francis July 13, 1920 2,235,552 Gilbertson Mar. 18, 1941 2,420,480 Ivandick May 13, 1947 2,430,207 Best Nov. 4, 194'?

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