US1320457A - Blindstitch device for sewing-machines - Google Patents

Description

APPLICATION FILED JAN.2 19!} Patented Nov. 4, 1919.

2 W J 5 4. j M

A. H. DE VOE.

BLINDSTITCH DEVICE FOR SEWING MACHINES.

APPLICATION FILED JAN.2 1917 1,320,457. Patented Nov. 4, 1919.

2 SHEETS-SHEET 2.

ATTORNEY ALBERT H. DE VOE, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO THE SINGER MANUFAC- TURING COMPANY, A CORPORATION OF NEW JERSEY.

BLINDSTITQH DEVICE FOR SEWING-MACHINES,

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed January 2, 1917. Serial No. 140,122.

following is a specification, reference being had therein tpthe accompanying drawings.

This invention relates to sewing machines equipped for blind-stitchin and has for an object to provide a machine which will simultaneously stitch upper and lower plies of fabric together or to the opposite faces of intermediate material in such a manner that the connecting portions of the stitching thread or threads between adjacent needlepunctures will not be visible at either side of the seam.

More specifically the invention has for an object to provide a machine which will simultaneously blind-stitch upper and lower tapes together at their opposite margins to form a tubular structure, or to blind-stitch said tapes to the opposite faces of intermediate body-fabric which may include a previously formed seam, to be covered by said tapes, or which may present overlapping or abutted edge-portions to be simultaneously joined and covered by said tapes as they are stitched together.

A further object of the invention is to provide means for producing a fullness in a strip of material after it has passed over an inverting edge to compensate for any undue stretching of the material and to insure that said material will be stitched to the bodyfabric in normal or unstretched condition. The invention also contemplates the adjustment of said means to produce more than enough fullness to con'ipensate for any stretching of the material, whereby the latter may, if desired, be stitched to the bodyfabric in a rufiied condition.

A further object of the invention is to provide means for pulling the upper and lower strips of material from the supply.

Further objects of the invention will appear from the following description and claims.

The invention, in its preferred embodiment, comprises a sewing machine of the usual flat-bed type having a cloth-plate over which is disposed the usual head carrying a presser-bar and reciprocating needle-bar whose lower end terminates in a laterally extended needle-clamp carrying spaced eyepointed needles which cooperate with any suitable type of loop-taker mechanism, in the usual manner to form spaced rows of stitches. Secured to the Presser-bar is a presser-foot whose shank is formed with a tape-guiding slot and whose sole-portion is formed with a transversely extending tapeinverting edge which is spaced above the fab Pic-engaging surface of the resser-foot and is disposed in rear of and closely adjacent the paths of the needles.

Cooperating with the fabric-engaging surface of the presser-foot to feed the work is any suitable type of feeding mechanism which may comprise a four-motion feed-dog operating through a slotted throat-plate. In the present instance the throat-plate is provided with a narrow transversely extending slot whose opposite end-portions receive the descending needles and whose rear edgewall serves to invert a tape drawn forwardly beneath the throat-plate and upwardly through said needle-receiving slot. The rear edge-wall of the needle-receiving slot and the transversely extending forward edge of the presser-foot define a plane which is disposed parallel to and closely in rear of the plane of the needles, whereby the needles will split the upper and lower thicknesses of tape presented by the tape-inverting elements and connect said tapes by spaced rows of blind-stitches.

The presser-foot carries an adjustable, forwardly disposed, fulling or rufiiing blade which is actuated by the needle-bar andis directed rearwardly to engage the upper tape between the inverting element and the last stitch and to full in said tape to the extent desired. A pull-ofi' bar carried by the presser-foot and actuated by the needlebar is adapted to draw the material closely about said element, to insure accurate splitting thereof by the needles, and to pull the material from the supply. Preferably, the fulling blade is first actuated to engage and full in the material below the inverting element after which the pull-off bar is actuated to draw back any excess of material while holding the latter close to said inverting edge.

The feed-dog of, the machine is slotted to guide the lower tape and its rising and falling motion is taken advantage of to pull a length of lower tape from the supply prior to each feeding stroke in order that the tape may run freely over the lower inverting element without becoming unduly stretched or offering undue resistance to the action of the feeding mechanism.

In the accompanying drawings forming a part of this specification; Figure 1 is a perspective view of the machine showing the work in place. Fig. 2 is a left side elevation, partly in section, with the needles at their highest point. Fig. 3 is a similar view with the needles at their lowest point. Fig. 4: is an enlarged cross sectional view through the presser-foot and throat-plate. Fig. 5 is a front view showing the presser-foot in elevation and the throat-plate and feed-bar in section. Fig.6 is a horizontal section of the presser-foot and needles on the line 5-5, Fig. 5. Fig. 7 is a bottom plan view of the resser-foot. Fig. 8 is a plan view of a portion of the throat-plate. Fig. 9 isan enlarged sectional view similar to Fig. 4 but showing a modification of the invention and Fig. 10 is a perspective view of a seam formed by the machine.

In the embodiment illustrated, the invention comprises a flat-bed sewing machine of usual construction having a cloth-plate 1 over which is disposed the head 2 carrying the usual spring-pressed resser-bar 3 and reciprocating needle-bar whose lower extremity is extended laterally to form a needle-clamping head 5 in which are secured, in spaced relation, the eye-pointed needles 6 which may coiiperate with any of the wellknown loop-taker mechanisms to produce spaced rows ofstitches.

Secured to the presser-bar 3 by the screw 7 is the slotted lug 9 which pro ects rearwardly from a tape-guiding frame comprising a vertical plate 10 whoselower'end-pon' tion together with the lug 9 form the shank of a presser-foot 11.

Secured within a recess in the bottom face of the presser-foot 11 by a screw 12 is a fiat guide-block 18 whose forwardly disposed marginal portion is undercut at 13 to form a thin overhanging blade 14: whose forwardly disposed edge-portion let may be considered as a tape-inverting element which is spaced above the plane of the fabric-engaging surface of the Presser-foot and is disposed in a vertical plane at right angles to the line of feed and closely adjacent and parallel to the plane of the needles 6. The lower front, corner 15 of the guide-block 13 forms another tape-guiding element spaced below and rearwardly from the tape-inverting element 14 for a pu OSe to be described. The thickness of the guide-block 13 is made less than the depth of the recess into which it is fitted to provide a tape-receiving guideway 16 in the bottom face of the presserfoot.

Extending forwardly at opposite sides of the presser-foot and at opposite ends of the tape-inverting element 14 are the spaced overhanging toe-portions 17 which serve as edge-guides for the upper tape. The toeportions 17 are disposed above the plane of the bottom surface of the presser-foot 11 to permit passage of the reciprocatory fulling or rufiiing blade 18 beneath the inverting element 14! and across a plane defined by said element 14: and the corner 15, to full in or ruflie the tape.

The fullirig or ruflling blade 18, which may or may not be toothed at its active edge 19, is carried at the lower reversely curved end'of a lever 20 pivoted at its upper end between the spaced cars 21 projecting upwardly from the plate 10. Pivoted to the lever 20 at 22 is a bar 23 whose slotted lower end portion is secured in adjusted position against the side face of the lever 20 by a screw 24. A pair of coil-springs 25 projecting forwardly from suitable sockets in the plate 10 urge said lever to the position shown in Fig. 2. As the needle-bar descends the needle-clamping head 5 will strike the inclined front edge 26 of the adjustable bar 23 and force the fulling lever 20 to the osition shown in Fig. 3. The length 0 the fulling or rufiling stroke of the blade 18 i at 29 to the plate 10 and whose lower or 10- tive portion 28' is bent to assume a substantially horizontal position transversely of and above the sole-portion of the presserfoot 11. A coil-spring 30, projecting forwardly from a suitable socket in the plate 10, urges the pull-oil bar 28 to initial position, as shown in Fig. 2. The head after having deflected the fulling lever 20 to a position in which the front edge 26 of the adjustable bar 23 isparallel to the path of re.-

ciprocation ofsaid head, strikes the pull-ofi' lever 28 and deflects it rearwardly thus causing the horizontal or active portion 28 of said lever to deflect the upper tape 2% at a point between, the tape-guiding aperture 31 and the tape inverting element 14. Deflection of the tape it at this point serves to draw said tape snugly against the inverting edge 14 for penetration by the needles 6 and also serves to pull a length of ,be loosened to be free] tape from the supply through the aperture 31. The horizontal portion 28 of the pulloff lever 28 is notched at 32 to receive the needles during the first part of their down stroke.

In the present construction provision is made for passage of the under tape 2" forwardly beneath the-cloth-plate 1 and upwardly about the rear edge wall of a transverse needle-receiving slot. Supported by the cloth-plate 1 is the throat-plate 33 formed with feed-do receiving slots 34 and transversely recesse in front of said slots to receive an auxiliary throat-plate 35 provided with a narrow slot 36 to receive the needles 6 and under tape 25. The rear edgewall 37 of the slot 36 constitutes an under tape-inverting element which is parallel with the upper inverting element 14 and, like the latter, is located substantially at the stitching point. In other words, the tapeinverting elements 37 and 14' define a plane which is arallel to and closely adjacent the plane of t is needles 6. Screwed to the under surface of the auxiliary throat-plate 35 is a tape-supporting plate 38, Fig. 4, whose rear edge-portion extending under theslot 36 is beveled at 39 and notched at 40, 40, Fig. 8, to receive the needles 6. The beveled edgeportion 39 serves to support the tape t close to the under surface of the auxiliary throat-plate 35 and causes said tape to be bent sharply about the inverting element 37.

Means are provided for pulling the under tape t from the suppl in order that said tape maybe free to e drawn upwardly through the slot 36 when the work is fed. In the present embodiment the usual fourmotion feed-bar 41 carrying the feed-dog sections 42 is formed with a substantially horizontal tape-guiding slot 43 extending under said feed-dog sections 42 and serving to guide the tape running forwardly through the passageway 44 beneath the cloth plate 1. When the feed-bar drops at the end of a feeding stroke it will deflect the length of tape t between the passageway 44 and slot 37 and pull a length of tape from the supply through said passageway. When the feed-bar rises from the position shown in Fig. 3 to begin a feeding stroke the tape will drawn through the slit 36 as the work is ed.

In the modification of the invention illustrated in Fig. 9 the tape engaging element 15, which is analo 'ous to the corner 15 in Fig. 4, is projecte forwardly beneath the tape-invertmg element 14'. The tape-guiding elements 14 and 15 are spaced apart and are both carried by the block 13* Which in other res ects is similar in construction to block 13, ig. 4. The fulling blade 18' is adapted to pass between said elements and is provided with a non-toothed tape-engaging edge 18*. In this form of the invention the fulling action of the blade is obviously increased and amounts practically to a ruffiin action.

V hile the machine isobviously operative without the described tape-fulling and pulloff devices, the provision of some such devices is desirable in order that tape which stretches easily, such as bias woven tape, may be incorporated in the finished scam in a normal or unstretched condition. The fulling blade 18 accomplishes this result with regard to the upper tape t. The pullofi devices serve to supply loose tape to avoid undue stretching thereof when drawn over the inverting elements 14 and 37 during a feeding action. Said devices also serve to draw the tapes snugly about the inverting elements for resentation to the descending needles. W en it is desired to simultaneously join and cover the marginal portions of two pieces of body-fabric the machine may be provided with a-fabric guide,

- ginal portions to the needles.

In Fig. 10, which illustrates a seam formed by the above described mechanism, the marginal portions a and a of the pieces of body fabric are folded inwardly and 'joined by means of the upper and lower tapes t and t which are connected together by the spaced rows of stitches comprising spaced'series of keyed, penetrative, threadloop structures 8 and connecting thread portions 8' extendin along the hidden, surfaces of said tapes. ach of the enetrative thread-loop structures 8 passes t rough the intermediate body-fabric material and enters and emerges from the inner or hidden surfaces of the upper and lower plies of material t and t, preferably without showing at the outer or visible surfaces thereof.

It is to be understood that the form and arrangement of the various parts disclosed are susceptible of material modification.

without departure from the invention.

Having thus set forth the nature of the invention, what I claim herein is -1. In a sewing machine, in combination, stitch-forming mechanism including a reciprocatin'g needle, feeding mechanism, and upper and lower tape-inverting elements having tape inverting edge-portions located substantially at but slightly in rear of the stitching point in a plane parallel to the needle and at substantially right angles to the line of feed. I

2. In a sewing machine, in combination, stitch-forming -mechanism including spaced parallel reciprocatingneedles, feeding mechanism, and upper and lowertape-inve'rting elements havi tape inverting edge-por tions disposed in a plane in rear of and closely adjacent the plane of said needles.

3. In a sewing machine, in combination, stitch-forming mechanism including a needle, feeding mechanism, a. guide frame having a forwardly disposed edge about which the material to be stitched is supported for penetration by said needle, and means moving in the direction of feed to full in said material between said edge and the last stitch.

4:. .In a sewing machine, in combination, stitch-formin mechanismincluding a needle, feeding mec anism, forwardly directed means located substantially at but slightly in rear of the stitching point for inverting a layer of fabric, and fulling in means acting in the direction of feed on the inverted portion of said fabric between the inverting means and the stitching point before it is stitched.

5. Ina sewing machine, in combination, a throat-plate, stitch-forming mechanism. including a needle, feeding mechanism,separate elements located above and below the plane of said throat-plate andsubstantially at the stitching point for invertin upper and lower plies of fabric, and fu ling in means acting on the inverted portion of one of said plies before it is stitched.

6. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, a. presser-member havin a work-engaging surface and, formed wit an edge-port1on extending transverse to the line of feed about which the material to be stitched. is folded for penetration by said needle, and a fulling device acting upon the material between said edge-portion and work-engaging surface.

7. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, feeding. mechanism, means located substantially at the stitching point for inverting upper and lower strips of fabric, and pull-oil? devices acting, respectively, on each of said strips between said inverting means and"the supply.

-8. In a sewing machine, in combination,

, stitch-foi-ming mechanism including a reciprocating needle, feeding means including a plate having a forwardly disposed ed e located substantially at the stitching point for inverting a strip of fabric, a falling device actingin the direction of feed upon said strip between said inverting means and the last stitch, and a pull-off device acting upon said strip between. said inverting means and the supply.

9. In a sewing: machine, in combination,

stitch-forming mechanism including a re ciprccating needle, feedingmechanism, guide-frame having a forwardly disposed edge over which the material to be blindstitcbed is drawn, and a fulling device positioned to act in the direction of feed upon the material between said edge and the titched portion of the work.

10. In a sewing machine, in combination,

mechanism,

ciprocating needle, feeding mechanism including a work-engaging member, a pressermember member to feed the work and presenting an edge over which the material to be blindstitched is drawn for penetration by said needle, and a fulling device acting upon the material between said edge and work-engaging member.

11. In a sewing machine, in combination, a reciprocating needle, feeding mechanism including a work-engagingv member, a presser-mem'ber presenting an edge over which the material to be blind-stitched is drawn for penetration by said needle, and a reciprocatory fulling member upon the material between said edge and work-engaging member and timed to engage and full in the material prior to penetration thereof by said needle.

12. In a sewing machine, in combination, feeding mechanism including a feed-dog, a presser-foot formed with a tape-inverting edge, a reciprocatory blade pivotally mounted upon said presser-foot and adapted to engage and full in the tape below said edge, and stitch-forming mechanism including a needle adapted to reciprocate in a path closely adjacent said edge.

'13. In a sewing machine, in combination, stitch-forming mechanism including a needle, feeding mechanism, a presser-foot supcoiiperating with said feeding acting ported in rear of said needle and having an edge-portion for inverting a strip of material while presenting it to said needle, and

a reciprocatory fuliing blade adapted to pass beneath said inverting edge-portion at the end of its fulling stroke.

14: In a sewing machine, in combination,

a"rciprocating needle-bar carryinga neestitch-forming mechanism includingv a re- 7 ciprocati-ng needle, a presser-member having spaced work-guiding surface portions one of which is disposed closely ad acent the needie-path, whereby the material to be biindstitched is presented for penetration by the needle, and a fulling device aving anoperative edge adapted to cross a line connect ing said surface portions.

16. In a sewing machine, in combination, stitch-forming mechanism including a re ciprocating needle, feeding mechanism, a throat-plate having a needle -aperture through which the material to be stitched passes upwardly and is presented in a transversely folded condition for penetration by said needle, and means sustained below said aperture for supporting the fold of material against the thrust of said needle.

17. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, feeding mechanism, a throatplate having a needle aperture through which the material to be stitched passes upwardly and is presented in a trans said strip between the needle apertureand the source of supply.

.19. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, four-motion feeding mechanism, a throat-plate having. a needle aperture through which a strip to be stitched passes upwardly, and means whereby an element of said feeding mechanism serves as a pull-ofi' for said strip prior to a feeding stroke.

20. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, feeding mechanism including a feed-bar, a throat-plate, and s aced. strip-guiding elements below the wor engaging surface of said throat-plate, saidfeed-bar being adapted to engage and defiect said strip between said elements.

In testimony whereof, I have signed my name to thislspecification.

ALBERTH. DE VOE.

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