US2470914A

US2470914A - Blind stitching apparatus

Info

Publication number: US2470914A
Application number: US544051A
Authority: US
Inventors: Sylvester J Birginal
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-07-08
Filing date: 1944-07-08
Publication date: 1949-05-24
Anticipated expiration: 1966-05-24

Description

' May 24, 1949.

3 Sheets-Sheet 1 Filed July 8, 1944 W a 8i ZW w. 1 4 a Z/ .Z 7 Q T c m d a war-kg 51s May 24, 1949. s. J. BIRGINAL BLIND STITCHING- APPARATUS 3 Shee'ts-Sheet-Z Filed July 8, 1944 Fla- . [In ---i May 24 1949.

Filel July 8, 1944 s. J. BIRGINA'L BLIND STITCHING APPARATUS 5 Shee ts-Sheet s Patented May 24, .1949

UNITED STAT This invention relates to blind Stitching apparatus, and more particularly to an attachment for a conventional sewing machine adapted to convert it into a blind hemmer.

One feature of this invention is that it provides improved blind stitching apparatus; another feature is that the apparatus embodying this invention may be used in blind sewing work of flat or tubular design on the conventional sewing machine, preferably of the power or commercial type, without the need of a tubular knee, a special bed, or the like; still another feature of this invention is that it includes means for precision adjusting the position of means guiding the material being sewed, this adjustment being with respect to the path of movement of the needle of the sewing machine and enabling proper blind stitching of materials of widely varying thicknesses; yet another feature of this invention is that the adjusting means includes motion-reducing connections and calibrated indicating means facilitating setting of the apparatus for the material to be blind stitched; a further feature of this invention is the provision of a spring-urged fold guiding arm for holding the material being sewed in the desired relationship with the guiding means; and still a further feature of this invention is that the guide plate and associated pressure member for guiding the material being sewed may both be readily swung out of operative position to enable the machine to be used for ordinary sewing without the necessity of removing the blind stitching apparatus. Other features and advantages of this invention will be apparent from the following specification and the drawings, in which:

Figure 1 is a side elevational view of the head and a portion of the bottom of a sewing machine including blind stitching apparatus embodying my invention; Figure 2 is a fragmentary enlarged detail view of a portion of the apparatus shown in Figure 1; Figures 3, 4 and are illustrative of material during and after blind stitching of a hem therein, Figure 3 being a sectional view of the material immediately after a stitch has been made therein, Figure 4 being a similar sectional view of the material unfolded into the shape in which it is worn, and Figure 5 being a fragmentary view of the surface of the material indicating the path of the stitching; Figure 6 is a plan View of the throat plate and a portion of a bed of a sewing machine together with blind stitching apparatus embodying my invention as illustrated in Figure 1; Figure 7 is a sectional view along the line 'l-1 of Figure 6; Figure 8 is a section view along the line 8-8 of Figure 6; Figure 9 is a sectional view along the line 9-9 of Figure 6; Figure 10 is a side elevational view of my special presser foot and guiding arm in blind stitching position; Figure 11 is a front elevational view of the parts shown in Figure 10; Figure 12 is a view along the line l2l2 of Figure 10; and Figure 13 is a view similar to Figure 11, but with the guiding arm up in inoperative position.

In finishing the bottoms of mens trousers, the hems of womens skirts and the like, it is good tailoring practice to effect the desired hemming by blind stitching. In blind stitching, the thread is run clear through the upturned piece of ma.- terial which will be concealed, but is run into and out of the piece of material on the outside of the seam, rather than through this material, so that the stitching is not visible from the outside in the finished garment. Blind stitching by hand is a slow and laborious process; and blind stitching of articles of tubular design on sewing machines has always heretofore involved the use of special blind stitching sewing machines with tubular knees and special beds, these machines being expensive and not being suitable for ordinary sewing, so that they lay idle most of the time.

I have devised and am here disclosing and claiming an attachment which converts the ordinary sewing machine into a blind hemmer; which enables blind hemming to be done very quickly and easily on materials of various thicknesses; and which is so arranged that it does not in any way impede or hinder normal use of the sewing machine for conventional stitching. I preferably embody my invention in an attachment comprising parts which replace the conventional throat plate and slide plate of the ordinary sewing machine, it only being necessary to loosen a couple of screws holding the conventional throat plate in place, to remove it, to replace it and its associated slide plate with my attachment; which replaces the conventional presser foot of the machine with my special presser footand guiding arm; and which replaces the conventional dog or feeder members with similar but longer members. My attachment preferably consists of three units, one comprising a throat plate, a slide or mounting plate slidably associated with the throat plate, actuating means for effecting precision adjustments of the position of the mounting plate with respect to the throat plate, and a material guiding plate pivotally mounted on the mounting plate; another comprising a presser foot with a guiding arm spring-urged toward the guiding edge of the guiding plate; and

will be more fully described later, serves to hold,

down the material being sewed; and a feed comprising the horizontally reciprocable. toothed:

members I6 and Il (best seen in Figure 6) serves to move the material in desired synchronism with needle reciprocation. These parts of a sewing machine will for the most part not be further described here, it being understood that my blind stitching attachment may be used with the conventional sewing machine.

As-may be best seen in'Figures- 6-9, the throat plate I8 is of conventional shape, andis providedwith athroat hole or.opening. Isa in which the needle is. reciprocable, Immediately to the left of-the throat. plate (speaking withrespect to thepositionsof .the parts as-shown in Figure 6) is a slide plate .or mountingplate here identified as I9.

members-;,and2I, slidable in channels 22 and 23.,rigidly mounted'on the=bottom of the throat plate I8,- as may. be best-v seen in Figure 9. The plate. I9 is thus so mounted, with-respect to the throat plate I8, that it=is movable toward and away from this latterplate; in the same plane as the plate, through-a limited range of movement. A. guide plate 24-.is. pivotallymounted on the mounting, member by. appropriate brackets and rivetsbest seen-in Figure 8, the rivets being identified .as 25 and 26. These provide a mounting such that .theguide plate 24= may be readily and;

quickly. swung from an operative position as shown in the drawings to an-inoperativeposition, this. latterv position being 1 the i result of swinging 1 the guidenplate about: 180- counter-clockwise, speaking with respect to thepositions of the parts as shown in the drawings, the guide'plate. 24.about an axis perpendicular to and spaced from thedirection of-movement of theneedle I4 enables the guide plate to be quickly and easilymoved fromaposition where its guidingedge 24a is .closely adjacent the path of needle movement toa position where the plate is swung completely out of the way and substantially fiat with the bed, so that there is no hindrance to normal sewing. operations with the machine.

The way in which my attachment facilitates blind-stitching and more particularly blind hemming will be best understood from a consideration of Figures 2-5, inclusive. Referring first to Figure 2,-it will be seen that the material to be hemmed, as the bottom of atrouser' leg here identified as 28, has a portion 28a overlying the guide plate 24,

a portion 28b bent around the guiding edge 24a of the guide plate, a portion 280 extending back to the left under the guideplate, another curved or folded portion 28d, and a straight portion 28c. extending back under the portion 28c and slightly out beyond the needle, these portions 280 and 28a lying on each other between the throat plate I8 and the guide plate 24.: The material is so placed,-

duringthis folding,v that-the wrong side of the material, faces .upwardly in" the part -28a,- downwardly in thepart-28e andupwardlyagain in the- This plate has soldered or otherwise rigidly attached tov its-bottom a pair of slide That is, pivoting of 4. part 286. The guiding edge 24a of the guide plate is preferably spaced from the center of the path of movement of the needle I4 by a distance equal to about the thickness of the material, so that during the sewing operation the needle pierces the folded end portion 28b in the manner shown, and then passes straight through the righthand end of the portion 28a of the material. The fold 28b of the material is held in proper relation tothe guiding edge 24a of the-plate 24by the arcuate surface of a pressure shoe 49a at the end of a guiding arm mounted on my special presser foot, the guiding arm and presser foot being bestseen in Figures 10 to 13, and more fully described, later.

As the material is moved beyond the stitching point, it appears: as illustrated in Figure 3, the parts ofthe material being stitched together by the'thread' 29. When the hem has been finished and the fold or bend 28b is straightened out, the material appears asshown in Figure 4 in cross section, and in Figure-5 in elevation, the stitching! being shown in dotted lines because it is not visible through theright side: of the 'material.

It will be apparent'that the curved or-bent=portion-28d becomes the bottomend of the trouser leg, the right-side of the material being up as is il-lustrated in Figure 4, and-the stitchesformedby" the thread 29 coming out of thematerial only-- on the wrong side. The fact that' thisarrangement enables the wrong side-of 'thematerial'to' be up when it is being sewed, as in Figure 2*," enables the material to behandled without havingto slip it over a tubular knee or otherwise-' get part of it underneath the throat plate;

It will beimmediately apparentthat the spacing'of the guiding edge 24a-of" the guide platewith respect to the path of needle movement must vary with different thicknesses of material. With, the relatively thick material shown in the drawings for thepurposes of clearly illustrating-my invention, the space between theguiding edge; 24a and the needle I4 may befairly substantial. With thinner material, however, this spacing; would have to be decreased in order to ensure" passage .of the needle through approximately the 4 center of the folded or bent portion 28?). In order accurately and properly to adjustthe spacingbetween the-guiding edge and the needle, I'pro- 'vide, for moving the mounting member I9"and.;'

plate 24 toward and away-from thepath of the needle, actuating'means which includes motion. reducing connections. The pressure shoe, bein onthe end of apivotally-mounted, spring -,urgedi; arm, automatically accommodates itself to vari-] ous thicknesses of material and various positions of-the guiding plate.

Referring now more particularly to Figuresv 6". and '7, it will be seen that-the mounting plate, I9; has extending from the-leftiside'thereof an ex tension portion 3D,;which may be integral with, the mounting plate 011a separate piece'riveted, or otherwise permanently attached thereto. Pivotally mountedunder the mounting plate, for movement about the axis Si; is .a long 16V81I3Z. rigidly connected to ashort lever ,33,.the arrange ment being-in the-form of a .bell crankg The, short lever has its outer end pivotally connected; at- 34 to a connecting link 35 pivotally con nected to the throatplate atth point, 36.' It will be readily seen-that movement of the outer end of the of the lever 32 through ahgiyen,.distanoa, effects movement of the; mountin p1ate ,I9'. to,-= ward or away from,,.the,throat ,plate,,l8,- this. latter movement being only a very small fraction, as of the movement of the outer end of the lever 32. Since the guide plate 2 5 is carried on the mounting plate l9, movement of the outer end Of the lever 32 enables precise adjustment of the spacing between the guiding edge 24a and the path of movement of the needle hi.

In order to facilitate movement of the outer end of the lever 32 and locking of the parts in any desired position, the lever has rigidly mounted therein near its outer end a threaded stud 38 passing up through a slot 39a and provided with a knurled knob or actuating member 38a. When it is desired to adjust the position of the guiding plate, the knob 38a is grasped, turned counterclockwise sufiic'iently to unlock the mechanism, and the lever moved to the desired position, whereupon the knob is again tightened up to hold the actuating parts and guide plate in the position to which they have been set. To facilitate proper setting of the parts, the outer end of the lever 32 is turned back to form an indicating pointer 32a cooperating with an arbitrarily graduated scale on the arcuate outer end of the extension plate 30. This scale may be used by the operator accurately to predetermine the proper spacing for blind hemrning materials of known types and weights.

Referring now more particularly to Figures to 13, inclusive, my special presser foot and guiding arm attachment will be more fully described. The presser foot 40 comprises a substantially conventional foot portion 400. and a vertical shank portion deb terminating in an attachment portion with two slots tile and Md. The shank is adapted to be mounted on a conventional presser foot supporting member 4! in either of two positions depending upon which mounting slot is used. A thumb nut screw 42 is threaded into the lower end of the supporting ember M, and is adapted to be received in one or the other of the two mounting slots. When the stud is in the slot 48d as illustrated in the drawings, the presser foot is in what may be termed blind stitching position; but when normal sewing is to be done the thumb nut is loosened and the presser foot so mounted that this stud lies in slot 680.

Since these slots are spaced apart (five-sixteenths inch from center to center in the particular embodiment illustrated in the drawings, although this distance might vary on diilerent machines), this results in two difierent corresponding positions of the presser foot. Referring more particularly to Figure 12, it will be seen that when the mounting is as illustrated in solid lines, the needle hole IBa is just slightly beyond the end of the presser foot; whereas, when slot 46c is used for mounting, the needle hole lSa is in the position shown in dotted lines in this figure, for conventional sewing. In order to provide proper feeding of the material in either of these two difierent positions of the presser foot, the toothed feed means 43 is made longer than is normally the case, and moves in a correspondingly longer slot in the throat plate l8.

At the back of the presser foot 40 near the junction of the foot portion with the upwardly extending shank, a transverse opening receives a threaded shaft 44 providing an extension of a mounting bracket 45. This shaft is held in place by a knurled nut 56, with spring washer means here identified as 41 between the nut and the shank of the presser foot, this means being here shown as two dished washers of spring metal.

The mounting bracket 45 has mounted on it,

for pivotal movement about an axis provided by a rivet 48 at right angles to the shaft 44, a guiding arm here identified as 49. This guiding arm is provided at its outer end with a pressure shoe 49a which, as has been described earlier and as may be best seen by reference to Figure 2, is adapted to press against the fold of the material bent around the guiding edge 24a of the guiding plate. A wire spring 50 is coiled around the rivet 43 and so arranged as to constantly urge the arm in a clockwise direction (speaking with reference to the position of the parts as shown in Figure 12), so as to cause the shoe 49a to maintain constant pressure on the material feeding along the guiding edge of the guiding plate 2 5. When it is desired to do conventional sewing the guiding arm is swung about the axis provided by the shaft 44 to the vertical position shown in Figure 13, where it is out of the way and does not interfere with normal stitching. That is, when blind stitching is being done the presser foot and guiding arm are in the position shown in Figures 10, 11 and 12; whereas when it is desired to do conventional stitching, the presser foot is mounted in its other mounting slot Mo and the guiding arm is swung up out of the way into the position shown in Figure 13. The spring washer 4'? provides frictional means for holding the guiding arm in either of two positions.

As will be readily apparent from reading the foregoing description, I have provided attachment means, in the form of a unit replacing the conventional throat plate, a unit replacing the conventional presser foot, and feed dogs replacing the conventional dogs, which converts any ordinary sewing machine into a blind stitching machine or blind hemmer. With my attachments blind stitching can be done quickly, easily and accurately. Yet the attachments are so arranged that the parts used in blind stitching (speaking more particularly of the guiding plate 24 and the guiding arm (l9) may be quickly and easily flipped or pivoted out of blind stitching position into an I inoperative position which permits conventional sewing to be done on the machine without the necessity of removing the attachments.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. In a sewing machine having a reciprocal needle, and a presser foot blind stitching apparatus of the character described, including: a guide member adapted to have a material-guiding edge closely adjacent the path of movement of the needle; a mounting member having the guide member pivotally mounted thereon, about an axis perpendicular to and spaced from the line of movement of the needle, the mounting member being movable in a plane perpendicular to the direction of movement of the needle; actuating means for moving the mounting member to adjust precisely the position of the guiding edge of the guide member with respect to the path of movement of the needle, the actuating means including a manually movable actuating member and a motion-reducing actuating connection between said actuating member and the mounting member; a guiding arm pivotally mounted on the presser foot for movement about two axes at right angles to each other, one end-of' t'he guiding arm being provided with a pressure shoeadapted to lie adjacent said material guiding edge for pressing the material being sewedagainst the guide means; and spring means for urging-the pressure shoe towards the guide means.

2. Apparatus of the character claimedin claim 1, including means for locking the guide means in any position to which it maybe adjusted.

3. In a sewing machine having a reciprocal needle, a slotted throat .plate 'and a presser foot supporting member, apparatus including: a presser foot having means for connection 'to said supporting member in two space'dipositions longitudinally of the line of stitch; a guiding arm pivotally mounted on saidpresser foot and having an end adapted to lie in front-of one end of the presser foot; and feed means operable in the slots in said throat plate and ef 'sufilcientlength to effect proper feeding of the material beingsewed in either positionof the presser foot.

4. Blind stitching apparatus of the character described for use in a sewing machine having a reciprocal needle and a presser foot supporting member, including: a throat plate having slots therein for feed means and a hole adapted to receive the end of the needle; a guide member adapted to have a material-guiding edge closelyadjacent the path of movement of the needle; a mounting member having the. guide member pivotally mounted thereon, about an'axis perpendicular to and spaced from the line-of movement of the needle, the mounting member 'being movable in a plane perpendicular to the direction of movement of the needle; actuating means for moving the mounting member to adjust precisely the position of the guiding edgeof the-guide member with respect to the path of movement of the needle, the actuating means including a manually movable actuating member and a motion-reducing actuating connection between said actuating, member and the mounting member; a presser foot having means-for connection to saidsupportingmember in two spaced positions longitudinally of the line of stitch; a guiding arm: pivotally mounted on saidpresser footand having an end adapted to lie in front of one end of the presser foot; spring means for urging said end of the guiding arm toward said material-guiding edge to press the material being sewed. thereagainst;

and feed means operable in the slots in said throat plate and of suific'ient length 'to effect proper feeding'of the material being-sewed in eitherposition of the presser foot.

5. In a sewing machine having a reciprocal needle and presser foot supporting means, apparatus of the character described for selectively material-guiding edge closely adjacent the pathof movement of the needle and when-in' the-o'the'r position presenting no interference-with conventional stitching; a pivotally mounted pressure member movable between two limitingpositions' and adapted to hold the material against the guiding edge of the guide member when in one position and when in the other position presenting no interference with conventional stitching-y actuating means for precisely "adjusting the position of one of said members with respect to'the path of movement of the member; spring means Zddo'gs, apparatus of the character described foroperative'on the other memberto urge'it toward theadjustable member; a presser foot movable between two positions, one closely adjacent the path of movement-of the needle forconven'tional sewing and the other further therefrom for blind stitching; and feed dogs cooperating with the pressure foot in both 'of its positions.

6. In a sewing machine having a reciprocal needle, presser foot supporting means, and feed dogs, apparatus of the character described for selectively enabling blind stitching or conventional 'through-and-through stitching, including: a supporting p'la'te adapted'to be attached to the sewing machine; a first guide member both slidably and pivotally mounted with respect to the plate, the pivotal mounting providing for movement about a horizontal axis between two limiting positions, this guide member-when in one position having a material-guiding portion closely adjacent the path of movement of the needle, the construction and mounting being such that saidportion is freely movable vertically duringstitching, the guide member when in the other position presenting no interference with conventional stitching; a second pivotally mounted guide member movable between two limiting positions and adapted to hold the material against the guiding portion of the first guide member when in one position and when in the other po sition presenting no interference with "conventional stitching; spring means operative on said second guide member, when 'inimaterial guiding position, to urge it toward the first guide mem-' her; and manually operable motion-reducing actuating means for slidably moving and: 'precisely adjusting the position of said first guide member.

7. In a sewing machine having a reciprocal needle, presser foot supporting means, and feed. dogs, apparatus of the character described; for selectively enabling blind stitching or conventional through-and-through :stitohing, including: a supporting plate adapted to be attached: to the sewin machine; a firstguide memberboth sl-idabl-y and pivotally mounted with respect tothe plate, the pivotal mounting providing for. movement about ahorizontal axis between two limiting positions, this guide member when in one position having a material-guidingportion=closely adjacent the path of movement of the needle, the construction'and mounting "being such thatsaid, portion is freely movable vertically during-s'titch--' ing, the guide member when inthe other 'position presenting no' interference with conventional stitching; a second pivotally mountedvguide :mem-

member, when in materialeguiding position, to

urge it toward thefirst guide member; manually operable motion-reducing, actuating means for slidably movin and precisely adjusting, the position of said first guide member; and a presser foot. movable longitudinally of. the lineof stitch, between two positions, one closely adjacent the. path of movement of the needle for. conventional sewing and the other further therefrom .-for .blind stitchin the presser foot being, adapted to cooperate with the feed dogs inboth of its positions.

8. In a sewing machine having a reciprocal needle, presser foot 'supportingm'eans, and feed enabling blind stitching, including: a supporting plate adapted to be attached to the sewing machine; a first guide member both slidably and pivotally mounted with respect to the plate, the pivotal mounting providing for movement about a horizontal axis, this guide member when in one position having a material-guiding portion closely adjacent the path of movement of the needle, the construction and mounting being such that said portion is freely movable vertically during stitching; a second pivotally mounted guide member movable between two limiting positions and adapted to hold the material against the guiding portion of the first guide member when in one position; spring means operative on said second guide member, when in material-guiding position, to urge it toward the first guide member; and manually operable motion-reducing actuating means for slidably moving and precisely adjusting the position of said first guide member.

9. In a sewing machine having a reciprocal needle, a presser foot, and feed dogs, blind stitching apparatus of the character described, including: a first guide member adapted to have a portion closely adjacent the path of movement of the needle, this member being movable for adjustment in a direction perpendicular to the direction of movement of the needle, and having its guiding end freely movable vertically; actuating means for precisely adjusting the position of the first guide member with respect to the path of 10 movement of the needle, the actuating means including a manually movable actuating member and a motion reducing actuating connection between said actuating member and said guide means; a second guide member adjacent said first guide member for pressing the material being sewed thereagainst; and spring means for urging the second guide member toward the first guide member.

SYLVESTER J. BIRGINAL.

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

UNITED STATES PATENTS Number Name Date 814,603 Herman Mar. 6, 1906 871,454 Stevens Nov. 19, 1907 1,288,391 De Voe Dec. 17, 1918 1,649,360 Merrow Nov. 15, 1927 1,864,452 Lutz June 21, 1932 2,021,201 Roos Nov. 19, 1935 2,187,237 Jordan Jan. 16, 1940 2,311,407 McFalls Feb. 16, 1943 FOREIGN PATENTS Number Country Date 10,237 Great Britain May 5, 1903 15,917 Great Britain July 3, 1914 397,325 Great Britain Aug. 24, 1933