US2769415A - Attachment for blindstitching - Google Patents

Description

Nov. 6, 1956 v. J. slGoDA ATTACHMENT FOR BLINDSTITCHING Filed Aug. 27, 1952.

5 Sheets-Sheet l INVENTOR. l//C70AP d5/Goo4 TTCRNE'Y Nov. 6, 1956 v. J. s'lGoDA 2,769,415

ATTACHMENT FR BLINDSTITCHING Filed Ag.' 27, 1952 5 sheets-sneer 2 IN V EN TOR. V/co@ [51 sop/1 BYl 2 ATTORNEY Nov. 6, 1956 v J, slGODA 2,769,415

ATTACHMENT FOR BLINDSTITCHTNG Filed Aug. 27, 1952 s shets-sneer 3 IN VUV TOR. l//c To@ d .S1600/J United States Patent O ArrAcrn/iENT non BLlNnsrrrcrm-1G Victor J. Sigoda, Great Neck, N. Y., assignor to Man-Sew Corporation, New York, N. Y., a corporation of New York Application August 27, 1952, Seriai No. 3%,631

13 Claims. (Cl. 112-140) 'Ihis invention relates to attachments for sewing machines for applying a folded strip of material, commonly known as piping, either to the raw edge of garment materials to form a piped binding or upon the surface of such materials for ornamental purposes. More particularly, it relates to that class of attachments in which the stitching is concealed Within the folds of the piping so that it is not visible on the normally viewed outer surface.

This manufacture is done in one operation by utilizing a folder which bends the longitudinal edges of the strip into reverse folds and then into U form. If desired, while in this U form, an additional layer of material such as the raw edge of -the bottom of a skirt may be inserted between the folded over edges and then stitched together. By feeding the folded over strip to the needle so that only the underlayer of the top fold is pierced, and then directing the needle through the remaining plies, it is possible to obtain an effect in which the stitching does not show on the outer or right side of the fabric. Apparatus whereby this may be accomplished has been shown in the patent to Seaman and Braf, 1,756,036 of April 29, 1930 and in the patent to Sigoda, 2,527,582, of October 31, 1950.

When attachments as disclosed in said patents are operated at comparatively slow speeds, satisfactory results are obtained. However when the speed of operation is raised, as has become increasingly necessary in these days of high speed production, several difficulties are met which prevent successful operation. In pending continuation application Serial No. 373,850, led August l2, 1953 (originally filed on June 15, 1950 as Serial No. 168,355, of which this is a continuation-in-part), the problems encountered due to undesired needle deections arising in high speed machine operation which cause the needle point to dance about in an irregular pattern, are discussed, and means are disclosed for overcoming such obstacles.

One further impediment experienced only in high speed machine operation has now been recognized as thread breakage resulting from the needle point occasionally nipping or cutting the sewing thread as it is Whipped about in the vicinity of the needle point in a highly erratic manner. The section of the thread which is subject to such action is only a small portion leading from the eye of the needle to the last stitch just sewn. The erratic pattern taken by this thread portion is the result of a number of factors such as needle reciprocation, machine vibration and the feed movement which cause a com-` plex interplay of forces to work on this thread portion so that at random intervals the thread lays immediately below the needle point as it begins its descent to form a stitch. When the thread is immediately below the point, the thread is severed. At other times the thread may be nicked and thus weakened sufficiently so that breakage occurs.

Accordingly, it is the principal object of this invention to provide means for eliminating thread breakage caused ICC by the needle point cutting or damaging the thread during high speed sewing. This has been accomplished in a novel manner by shifting the line of stitching laterally from the line normally taken due to the feed action. This displacement, which occurs during the sewing operation, is just enough to enable the thread to escape the needle point. The means provided for this are relatively simple, consisting of an oblique notch or relief in the forward edge or nose of the presser shoe and an oblique elongation of the needle hole in the needle plate. The eect of either, or both in combination, is such that the line of stitching is shifted oifside from the line normally taken.

Other objects will appear from the following detailed description of the attachment taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a View in perspective, showing the attachment as it would be attached to a standard sewing machine, part of the machine being omitted for clarity;

Fig. 2 is an exploded view of the attachment removed from the machine, taken in perspective, the parts being disassembled in their relative positions;

Fig. 3 is a view taken in cross section on line 33 of Fig. l;

Fig. 4 is a bottom view of the presser shoe showing the novel, obliquely disposed notch;

Fig. 5 is a plan view of the needle plate used with the attachment showing thercorresponding thread groove at one side of the needle hole;

Fig. 6 is a schematic representation showing various lines which Athe stitching may take with respect Ito the shoe in the absence of the nose notch and the needle plate thread groove;

Fig. 7 is a similar view showing how the line of stitching is shifted laterally parallel to the original line of stitching, under the control of the notch and groove on the work;

Figs. 8, 9 and 10 are cross-sectional, detail views taken respectively on lines 8 8, 9 9 and lib-10 of Fig. 1, showing how the fabric strip is progressively folded longitudinally as it proceeds through the folder on its passage to the blindstitching operation;

Fig. 1l is an enlarged, fragmentary, perspective View of the outlet end lof lthe folder;

Fig. l2 is a similar view showing how the folded strip emerges from the outlet of the folder and how the folded edges are disposed vertically as they pass about the end of the presser shoe in position for Vthe needle penetration;

Fig. 13 is a similar view showing the needle as it just begins to penetrate the innermost fabric ply;

Fig. 14 is a similar view showing the needle after penetration of the innermost ply and the lower plies;

Fig. 15 is a detail view, partly in cross-section, showing the blindstitched piping as it would be sewn to the edge of a garment, and

Fig. 16 is a detail fragmentary view in perspective of a portion of a modified form of presser shoe.

Only those portions of the base 10 and the needle head 14 of the standard sewing machine which are necessary for comprehension of the invention are shown. The head carries the usual needle bar 15 and pointed needle 16 and the presser foot bar 17. Base 10 carries the usual needle plate 23 (see Fig. 5), provided with needle hole 24, feed dog slots 26, and screw holes 27 by which the needle plate is secured to the machine bed 10. Needle hole 24 is provided with an obliquely offset elongation 25 the purpose of which will be subsequently explained.

i The complete attachment 20 has a recess 22 similar to that of the conventional presser foot which it replaces. It is secured to the foot bar 17 by means of the usual screw 21. Feed dog 19 cooperates with the presser shoe portion of the attachment to feed the work in the usual in operating relationship, these other main parts being the presser shoe portion 50, the counterdeector portion 6) and the fabric folder and guide portion 70.

Referring t Figs. Z and 3, body portion 3i) is provided at the bottom with an inverted, male T-section 31 on which a mating T-slotted section 51 of sho'e portion 50 may be mounted so that the latter may be supported in fixed vertical position, but may be moved horizontally as required to or from the needle 16. Member 3j) has a counterbored recess 32 in which compression spring 33 is received. One end of spring 33 bears on the inner Y face of recess 32 and the other end bears on a projecting lug l52 of shoe portion 50 when the parts are assembled. Spring 33 therefore serves to press shoe portion 56 rearwardly.

Thumbscrew 34 is threaded into a rear, upstanding projection 35 of body member 30 and has a tapered, conical point 36 which bears against a dimpled recess 53 -of lug 52. Manipulaiton of thumbscrew 34 can thus move shoe portion 50 forwardly against the tension exerted by spring 33 as the tapered point 36 is moved downwardly against lug 52.

' On one side of member 30, a horizontally disposed T- slot 37 is provided in which counterdeflector 60 may be slidably received. Counterdeector 60 is formed with a T-section 61 which fits slot 37. A threaded cross hole 38 is provided in member 30 to receive set screw 39 the point of which bears against faceV 62 to lock counterdeflector 60 in any adjusted horizontal positionwith respectV to needle 16.

Counterdeflector 6l) has a forwardly projecting portion 63 shaped into a platform section 64 with'a bent up nos'e 65 and a needle groove 66. The bent upvnose facilitates insertion of the fabric plies for thefsewing operation.

The needle groove portion 66 of platform 64is brought into contact with the surface of n'eedle 16 by adjustment of the horizontal position ofVcounterdeect-or 60 in T- slot 37, as required, after which Vset screw 39 is adjusted to lock the counterdetiect-or in fixed position.

' to be bound by the fabric strip which is folded in the Y,

folder and guide 72.'V Fig. l5 shows a typical form ofV Shoe portion 50 has a nose 53 with a notch 54, theV purpose of which will subsequently become clear, and a projecting arm 56, having a threaded hole 57a and a bear-Y ing hole 57h. Shoe'portion'50 also has a pair of intersecting threaded holes 5S and 59 to receive set screws 58a and 59a.

Folder 70 is mounted on projecting arm 56V of shoe portion 50 by an arrangement which allows adjustment of 'the horizontal position of the outlet 71 Vof folder 70 both laterally t-o and from the line of stitching as well as parallel thereto to and from the needle. Folder and guide portion 72 is secured to a mounting bracket portion 73 with solder or by any other suitable means. Bracket portion 73 is provided with an elongated sl-ot 74 lying parallel lengthwise with folder porti-on 72 through which slot mounting screw 75 may be passed and screwed into threaded hole 57a. A second elongated slot 76 perpendicularly disposed to slot 74 receives the eccentric shoulder 78a of folder positioning screw 78. Screw 78 has a lower bearing portion 78b which is received in bearing hole 57b of arm S6, and an extension having a peripheral groove 78C in which a lockring 78d is fitted to hold screw 78 in assembled position `on arm 56.

When screw 75 is loose, rotation of screw 78 in slot 76 causes folder porti-on 70 to move as a whole on arm V56 laterally to and from needle 16. Tightening screw 75'will lock folder portion 70 in adjusted position.

The adjustment of outlet 71 to and from the needle on Y a line substantially parallel to the line of stitching is accomplished by means of screw 58a, the point of which bears against the inner side 79 of outlet 71 when folder portion 76 is secured to arm 56. Screw 58a is adjusted other end 80e of spring 89 ts into a recess 55 (see Fig. Y

4) on the bottom of member 50. Y Y

By virtue of this arrangement, spring 80 tends to rotate folder portion 7i) about screw 75, (provided it isnot screwed down tightly) so that` outlet '71 moves away from the operator on an arcuate path about a pivot point represented by screw 75. Since the radius from this pivot point to the end of the outlet 71 is relatively long, this arcuate path lies substantially parallel to the line of feed. Accordingly, when screw'58a is threaded toward the operator, folder portion 70 is moved in thesame direction against the tension of spring 80. Cross screw 59a locks positioning screw 58a in its finally adjusted position so that screw 58a will not move due to machine vibration.

While positioning of shoe nose 53 by means of thumb-V time be fed through the folder and guide 72 make these additional adjustments desirable.

Referring to Figs. 8 to l0, the fabric folder and Yguide 72 is provided with suitable internal bends 83 which cause the strip edges toY fold over longtitudinally as theY strip is drawn through Ythe bends S3 towards the needle by the feed 4action of the machine for the subsequent blindstitchs ing operation.

j Platform 84 secured to fabric folder and guide 72 actsY as a support over whichVV a f piece of material, such as typically the raw edge of the skirt of a garment, maypass this work in which such a binding has been applied to a garment edge by the blindstitch operati-on. The'folder Vshown at 72 is conventional and forms no invention.

The methodof producing `the blindstitching with this attachment is substantially similar to that utilized in the device shown in the Seaman and Braf patent previously referred to. The outlet end 71 of folder '72 is shown in Fig. 11, and in Fig. l2, the folded `over strip is shown as Y it just leaves outlet 71, which is mounted Vso that it'is somewhat above nose 53. The folded strip in' leaving outlet 71 to pass about nose 53 therefore assumes an obliquely vertical position in a plane substantially'parallel to that of the needle path, as shown. By .proper positioning of outlet 71 with respect toneedle 16 as previously described, the folded plies will lay in the path of travel of the needle. As the position of nose 53 is adjusted horizontally with respect to the needle by manipulation of thumbscrew 34, the location of the upright section of the folded striprwill be adjusted so that the needle may intercept various of the plies of the strip. Where it is desired tok produce a blindstitch, the position of nose 53 is adjusted so that the needle will pass through the innermost part of the i piping is drawn rearwardly from themachine in the usual manner.

After the position of nose 53 has been properly adjusted to obtain the desired needle penetration, the counterdeector 60 has been located so that undesired needle vibration is suppressed as described more fully in the beforementioned application, and the folder outlet 71 situated for the particular material being drawn through the folder and guide 72, the sewing machine may be operated at high speed to produce piping. However, thread breakage can and does occur because the small amount of thread leading from the needle eye to the last stitch penetration may whip about beneath the needle point and at times will be in position so that as the needle descends, the point of the needle will nip the thread.

To prevent this random thread breakage, the line of stitching is shifted laterally to one side of the usual line of stitching. This is accomplished mainly through the agency of notch 54 in the nose 53 of the presser foot.

The interlocked sewing threads are anchored in the work at the last needle penetration. The rearward feed action of the feeding mechanism exerted on the work, tautens the top and bottom threads against the restraint of their respective tensioning devices. The tauted top thread will tend to find the shortest distance between its anchorage in the work and its tensioning device, and as it passes about the edge of nose 53, it will slip along this edge until some relatively low point which provides the shortest path is found. Such a low pointy is deliberately provided by notch 54, which will be noted, begins just to one side of the high point of nose 53 at which the needle makes contact through the fabric plies. v

To produce the desired lateral shift of the line of stitching, this notch runs downwardly at an oblique in clination to the right to the undersurface of the shoe. The tautened top thread will, in its quest for a low point, slip into this notch, and as the feed action draws the work rearwardly, the line of stitching will be shifted laterally, parallel to the usual line of stitching to a position in which theneedle point can no longer reach and nip the thread leading to the last needle penetration.

Sufficient clearance is provided in notch 54 to accommodate the fabric plies which are drawn into the notch by this action of the feed mechanism on the top thread.

'While this eect can be obtained solely by providing notch 54 in the presser shoe nose, it has been found that adding elongation 25 to the needle hole 24 accentuates and enhances it. Like notch 54, the groove 2S is obliquely disposed to the needle hole and in line with the rearward inclination of notch 54. The tautened bottom thread, drawn rearwardly by the feed action, also seeks the shortest path between its anchorage in the work and its tensioning device on the bobbin, and this path is provided by the obliquely disposed groove 25. Shifting of the bottom or bobbin thread into groove 2S also tends to shift the work so that the line of stitching is displaced laterally, thus augnenting the edect of the nose notch.

After the line of stitching is shifted laterally by the combined actions of the notch and groove, the feed movement causes the work to progress rearwardly on a line parallel to the normal line taken by the stitching in the absence of such shifting means. As shown in Fig. 6, the normal paths which the stitching may take may vary somewhat, but all are substantially in line with the line of feed. The controlled path taken by the line of stitching under the inuence of the notch and groove is shown in Fig. 7.

It has been observed that in many sewing machines wear or looseness in the support guides for the foot bar produces a tendency on the part of the presser shoe to oscillate about the foot bar axis across the line of feed. This causes a random shift of the edge of the presser shoe nose with respect to the needle which is of no consequence at slow speeds. As the speed of operation is "6! increased, this oscillation becomes'more pronounced, and in blind-stitching produced by the use of a presser shoe having a vertically rounded over nose on which the folded fabric plies are positioned for controlled needle penetration of the plies, at times, this shifting of the nose edge causes improper needle penetration.

lt can be appreciated that if the axis of the foot bar is considered as a pivot point, this oscillation will cause a change in the particular portion of the nose edge which comes into Contact with the needle through the material plies. The radials leading from the foot bar axis to points on the nose of a shoe which has a straight edge are of different lengths. Therefore, as the point at which the needle contacts the edge of the nose through the fabric plies shifts, a varying deiiection of these plies takes place causing non-uniform needle penetration.

it has been found that by rounding the nose 53 in a horizontal plane, as best indicated in Figs. 6 and 7, the ams of the foot bar being taken as the center of the arc of curvature, that proper needle penetration may be maintained. This curvature also tends to produce a shifting of the line of stitching offside from the line normally taken. This occurs because from the highpoint of this arc, that is, at whatever point the needle is in contact with the nose edge through the material'plies, there is a slope to one side or the other. As previously explained in connection with the notch 5d and groove 25, the thread tensions and the feed movement exert forces acting on the work which cause the work to shift along the slope on the nose edge. As shown in Figs. 6 and 7, since it is not desired to shift the work to the left, this arc joins the straight edge of the nose just about the center-line of the shoe.

Proper placement of notch 54 slightly to the right of the centerline as viewed in Figs. 6 and 7, directs the work displacement as desired, and the angle of the notch and groove and their respective lengths determine how far to the right the line of stitching will be shifted. In connection with notch 54 it has been learned that only the inner edge of the notch is effective in directing this work displacement, and accordingly, it is possible to re- -place notch 5d with an inclined relief 54a having an angularly disposed edge as shown in Fig. 16.

To understand why the thread is safe from nipping by the needle when the line of stitching is displaced, reference should be made to the schematic representations Figs. 6 and 7. In Fig. 6 it will be noted that the thread as it leaves the needle eye forms a small bend S5 as it passes from the right side of the needle, as so viewed, downwardly and over to the line of stitching. While this bend is small, at random intervals the thread may lay in position beneath the point of the needle so that it may be nipped.

As shown in Fig. 7, when the line of stitching is displaced by the control exerted by nose notch S4 and thread groove 25, the thread is led off at an angle, to the right, to the displaced line of stitching and no longer can find a position below the point of the needle where it can be nipped.

While the presently preferred embodiments have been described in detail for the purpose of illustration, it is to be understood that the invention is not to be limited to the details of construction shown and described, but is -to be construed broadly within the spirit and scope of the appended claims.

What is claimed, is:

l. In an attachment, for the production of blindstitohing in conjunction with the stitchforming, thread takeup and tensioning land feed mechanisms of a sewing machine, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread 1 leading to the last stitch penetration by the needle on its descending stroke which comprises angularly disposed means in -said shoe adapted to coactV with thel feed and Vthread take-up and tensioning devices for slipping the stitching as it is sewn so that the line of stitching is displaced laterally from the line normally taken.k

2. In an attachment for the production of blindstitching in conjunction with the stitchforming, thread take-up and tensioning and feed mechanisms of a sewing machine having a needle plate, said attachment being provid-ed with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the -folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading to the -last stitchV penetration by the needle on its descending stroke which comprises angularly disposed means in said shoe and complementary means in said needle plate adapted to coact with the feed and thread take-up and tensioning devices Ifor slipping the stitching as it is sewn so that the line of stitching is displaced laterally from the line normally taken.

3. In an `attachment for the production of blindstitching in conjunction with the stitchforming, thread take-up and tensioning and feed mechanisms of a sewing machine, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the folded fabric strip may be positioned for `selected needle penetration of the folded plies, that improvement for preventing interception of the th-read leading to the last stitch penetration by the needle on its descending stroke which comprises an angularly disposed notch in said presser shoe nose adapted to coact with the feed and thread take-up and tensioning devices for slip- :ping land stitching as it is sewn so that the line of Stitching is displaced laterally from the line normally taken.

4. In :an Vattachment for the production of blindstitching in conjunction with the stitchforming, thread take-up and tensioning and feed mechanisms of a sewing machine, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading to the last stitch penetration by the needle on its descending stroke which comprises. a notch in said presser shoe nose, said notch being obliquely disposed from the point where the needle makes contact with said nose through the folded fabric plies to the underside of said shoe adapted to coact with the feed and thread take-11p and tensioning devices for slipping the stitching, as it is sewn so that the 4line of stitching is displaced laterally from the line normally taken. Y

V5. In an attachment for the production of blindstitching in conjunction with the stitchforming, thread take-up and tensioning and feed mechanisms of a'sewing machine, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading to the last stitch penetration by the needle on itsV descending stroke which comprises an obliquely disposed, guiding edge portion in said presser shoe nose adapted to coact with the feed and thread take-up and tensioning devices -for slipping the stitching as it is sewn so that the lineof stitching is displaced laterally from the line nor- V.mally taken.

chine, said attachment -being provided with means for folding and guiding a fabric strip to be hlindstitched, and adjacent thereto, apresser shoe havinga nose over'the edge of which the folded fabric strip v4may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the Vthread leading to the last stitch penetration by the needle on Vits descending stroke which comprises an inclined relief leading from theV front edge of the presser shoe nose tothe bottom surface of said shoe, said relief having an `obliquely disposed guiding edge portion adapted to coact with the feed and thread take-up and tensioning devices for slippingV the stitching as it is sewn so that they line `of stitching is displaced laterally from the line nor'-Y mally taken.

7. In an attachment for the production of blindstitching in conjunction with the stitchforming, threadrtakeup and tensioning and feed mechanisms of a sewing machine, said attachment being provided with means for folding and guiding a fabric'stlip to be blindstitched, .and adjacent thereto, a presser shoe having 'a nose over the edge of which the folded fabric strip may be posiltioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading to the last stitch penetration by the needle on its descending stroke which comprises an obliquely disposed, guiding edge portion in'said presser shoe nose 'adapted to coact with the feed and thread take-upV and Y tensioning devicesk for slipping the stitching as it is sewn so that the line of stitching is displaced laterally from the line normally taken by said stitching, said presser shoe nose having a horizontal curvature characterized by la high point tangent to `the point where the needle makes contact with said nose through the fabric plies and a low point on said curve spaced in the direction in which the line'of stitching is laterally displaced from its normal line.

V8. In an lattachment lfor the production of blindstitching in conjunction with the stitchforming, thread takeup and tensioning 'and feed mechanisms of a sewing machine having a needle plate, said attachment being Vprovided with mean-s'for folding and guiding aV fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over lthe edge of which theV folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading tothe last stitch penetration by the needle on itsdescending stroke which comprises a needle hole in said Vneedle plate having a laterally oblique elongation adapted to coact with the feed and thread take-up and tensioning devices for slipping Ithe stitching .as it is sewn so that the lineV of stitching is displaced ylaterally from the line normally taken;

9. In an attachment for the production of blindstitching in conjunction with the stitchforming, thread takeup and `tensioning and feed mechanisms of a sewingj machine having a needle plate, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and Vadjacent thereto, a presser shoe having a nose over the edge of which the folded yfabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the thread leading tovr the last stitch penetra-tion by the needle on its descending stroke which comprises an obliquely disposed, guiding edge portion in said presser shoe nose and a needle hole in said needle plate having a laterally oblique elongation adapted to coact with the feed and thread take-up and tensioning devices for slipping the stitching, as it is sewn so that the line of stitching is displaced laterally from the line normally taken.

10. In an attachment for the production of blindstitching in conjunction with the stitchforming, thread take- -up and tensioning and feed mechanisms of a'sewing machine having a needle plate, said attachment being provided with means for folding and guiding a fabric strip to be blindstitched, and adjacent thereto, a presser shoe having a nose over the edge of which the folded fabric strip may be positioned for selected needle penetration of the folded plies, that improvement for preventing interception of the lthread leading to the last stitch penetration =by the needle on its descending stroke which comprises an obliquely disposed, guiding edge portion in said presser shoe nose and a needle hole in said needle plate having a laterally oblique elongation adapted to coact with the feed and thread take-up and tensioning devices for slipping the stitching, as it is sewn so that the line of stitching is displaced laterally from the line normally taken the angular direction of said guiding edge and of said needle hole elongation being substantially the same.

11. An attachment for sewing machines .for the production -of blindstitching in conjunction with the stitchforming .and feed mechanisms of the sewing machine comprising a main body member adapted to be mounted on the footbar of the sewing machine, said main body member being provided with an internal recess for a compression spring, means on said body member for mounting a shoe member in xed vertical position 'but in |horizontally adjustable position, means on said body member for mounting a thumbscrew in an obliquely inclined plane, and an arm on said body member on which a folder may be adjustably mounted, a compression spring retained in said recess, a shoe member mounted on said body member, said shoe member having an upstanding lug for contacting and compressing said spring, a thumbscrew carried -by said body member, said `thumbscrew having a tapered, conical point for sliding contact with said lug for horizontal adjustment of said shoe member to and from the stitchforming mechanism against the tension of said spring, `and a fabric folding and guiding member mounted on said arm with its outlet adjacent the stitchforming mechanism and the nose of said shoe member.

12. In an attachment for sewing machines for the production of blindstitching in conjunction with the thread tensioning, stitchforming and feed means including a footbar and a vertically reciprocating needle which randomly deviates from a desired, xed vertical path in high speed operation, a main body member having a vertical slot for receiving the footbar of the sewing machine for mounting thereon, an arm extending laterally from one side of said body member on which a strip fabric folder may be adjustably mounted, a folder mounted on said 10 arm for folding and guiding a fabric strip to the needle, means on said body for adjustably mounting a presser shoe member thereon for horizontal positioning with respeot to the needle, a presser shoe member having ka nose over the edge yof which the folded strip emerging from said folder may be bent for selected needle penetration, mounted on said body member, a horizontally disposed slot in the other side of said body in which a counterdeecior member may be ladjustably positioned to prevent undesired needle deviations, and a counterdeflector member mounted in said slot.

13. In an attachment for sewing machines for the production of blindstitching in conjunction with the thread tensioning, stitchforming and feed means including a footbar and a vertically reciprocating needle which randomly deviates from a desired, fixed vertical path in high speed operation, a main body member having a vertical slot for receiving the footbar of the sewing machine for mounting thereon, 'an arm extending laterally from one side of said body member on which a strip fabric folder may be adjustably mounted, a folder mounted on Isaid arm lfor folding and guiding a fabric strip to the needle, means on said body for Aadjustably mounting a presser shoe member thereon for horizontal positioning with respect to the needle, a presser shoe member having a nose over the edge of which the folded strip emerging from said folder may be bent for selected needle penetration, mounted on said body member, said nose being provided with an obliquely disposed guiding edge portion adapted to coact with the feed and thread tensioning devices for slipping the stitching as it is sewn so that the line of stitching is displaced laterally from the line normally taken to prevent interception of the thread leading to the last stitch penetration by the needle on i-ts descending stroke, a horizontally disposed slot in the yother side `of said body in which a counterdeflector member may be adjustably positioned to prevent undesired needle deviation-s, and a counterdeiiector member mounted in said slot.

References Cited in the file of this patent UNITED STATES PATENTS Re. 7,985 Bosworth Dec. l1, 1877 1,358,567 Moffatt etal Nov. 9, 1920 1,994,965 Seaman Mar. 19, 1935 2,020,478 Seaman Nov. 12, 1935 2,125,652 Seaman Aug. 2, 1938 2,130,198 Seaman Sept. 13, 1938 2,437,977 Seaman Mar. 16, 1948

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