US3512490A - Overcasting foot attachment for sewing machines - Google Patents

Description

May 19, 1970 D. L. WENER 3,512,490

OVERCASTING EQOT ATTACHMENT FOR SEWING MACHINES Filed April 29, 1968 LVVEA/"IUR.

30 34 az 54:40 Z. fl iA/fe W%,%,% a; M 265045 United States Patent 3,512,490 OVERCASTING FOOT ATTACHMENT FOR SEWING MACHINES David L. Wener, 324 N. Palm Canyon Drive, Palm Springs, Calif. 92262 Filed Apr. 29, 1968, Ser. No. 725,010 Int. Cl. D05b 29/00 US. Cl. 112-235 8 Claims ABSTRACT OF THE DISCLOSURE An overedge or overcasting presser foot attachable to a household zigzag sewing machine. Disposed between the presser foot forward edge and the needle opening is an edge guide wall. Projecting laterally from the base of the guide wall is a flat positioning blade that slides beneath the material margin to slightly raise the edge and position it against the guide wall to keep the edge in perfect alignment during stitching. A tongue extends rearwardly through the needle opening to assist in making the stitches sufficiently taut to prevent the edge from ravelling and curling.

BACKGROUND OF THE INVENTION The present invention relates to a presser foot attachment for a household zigzag sewing machine, and more specifically to an overedge presser foot having an edge guide for maintaining continuous accurate alignment between the presser foot and the raw material edge to achieve a neat finished edge.

An established technique for binding the untidy raw edges of material consists of using a conventional household zigzag sewing machine in conjunction with a presser foot that assists the sewing machine in binding the edge with overedge or overcast stitching. The presser foot rests upon and slides over the material edge while holding the material steady by pressing it against the machine table or platform as overedge stitching proceeds. In practice, it is difficult to keep conventional overedge presser feet in continuous alignment with the raw material ed-ge and therefore the completed stitched edge is often crooked, disorderly and unsightly. Ordinarily the sewing machine operator seeks to stitch a smooth edge by visually aligning the material edge with a straight guide wall or line of the presser foot (e.g., US. Pat. 2,950,696 to Miller).

Another prior art approach aimed at keeping the material edge and presser foot aligned during overedge stitching is characterized by attaching a vertically aligned edge guide to an outside section of the presser foot. This type of edge guide must extend below the plane of the flat presser foot under-surface and therefore the guide is either severely restricted by the thickness of the material or must be vertically adjusted to accommodate materials of varying thicknesses (e.g., US. Pat. 736,199 to Borton and US. Pat. 1,944,515 to Karle).

Another drawback of conventional presser feet is that they cause completed stitched edges to appear unfinished due to the fact that ravelling is not effectively prevented and the stitching is applied under excessive'tension so that the edge either curls or ridges. In accordance with one approach (e.g., the Miller patent previously mentioned) some of these disadavntages are sought to be overcome by attaching to the presser foot a tongue projecting rearwardly into the needle opening that accommodates the zigzag stitching action of the needle. Stitching is drawn over the tongue by the back and forth action of the needle and the tongue serves to sufficiently relax the tension in the stitching so that the eventually stitched edge is free of curling.

SUMMARY OF THE INVENTION Briefly described, the present invention comprehends a presser foot attachable to a household zigzag sewing machine for assisting the machine in binding material edges with overedge or overcast stitching. The presser foot includes a plate formed with a flat undersurface portion which slides over the marginal edge of the material to be stitched to hold the material steady during stitching. Formed through a central region of the plate is a typical needle opening for accommodating the zigzag stitching action of the needle. Disposed between the plate forward edge and the needle opening is a straight edge guide wall that bears against the raw material edge during stitching to keep the raw edge and presser foot in smooth mutual alignment. Arranged adjacent the guide wall is positioning means that functions to position the material edge in constant engagement with the guide wall. Preferably the positioning means is characterized by a flat positioning blade projecting laterally from the lower edge of the guide wall which provides a smooth angular transition between the vertical guide wall and the horizontal blade to prevent snagging the material edge. The positioning blade slides beneath the material margin and slightly raises the material edge into position against the guide wall. In accordance with one construction of the present invention, the guide wall is formed by an inner wall portion of an arm aligned in laterally spaced relationship from a second arm. A for ward portion of the second arm curves upwardly over the blade to define therewith a shallow entrance passageway through which the margin of the raw material is continuously fed to a location beneath the needle open ing. In order to relax tension in the stitches and therefore prevent curling or ridging of the completed stitched edge, the plate may include a tongue extending rearwardly into the needle opening where it terminates in a free end. Stitching loops freely slip over the free end of the tongue while being fed rearwardly to neatly bind the material edge. The tongue may be extended beneath an undercut section of the plate to define therewith a shallow guide slot which assists in guiding the stitching loops to their eventual stitching positions on the material edge. In order to further assist the presser foot in maintaining the marginal edge steady during stitching, the lower surfaces of the positioning blade and tongue are arranged in substantially coplanar relationship with the fiat undersurface portion of the plate. A connection element pivotally connected to a rearward section of the plate may be used for connecting the presser foot to the sewing machine.

The unique aspects and advantages of the present invention serve to eliminate or substantially minimize the previously mentioned disadvantages and defects of conventional presser feet. The edge guide wall and the positioning blade which continuously slides beneath the material mar-gin during stitching, coact to assure that the presser foot is maintained in constant alignment with the material edge so that a smooth regular edge can be achieved. The tongue simultaneously operates to relax the otherwise excessive tension in the stitching loops so that when the stitches are eventually woven into and around the edge, the edge is free of ravelling, ridging and curling.

BRIEF DESCRIPTION OF THE DRAWINGS The unique aspects and advantages of the present invention will be fully understood when the following detailed description is studied in conjunction with the drawings in which:

FIG. 1 is a perspective view of the overedge presser foot, showing the zigzag needle raised above the needle opening when the foot is connected to the sewing machine;

FIG. 2 is a bottom view of the presser foot, showing the material edge running over the positioning blade and under the tongue which extends beneath an undercut portion of the plate;

FIG. 3 is a front view of the presser foot, showing how one arm curves upwardly to slide smoothly over the material margin;

FIG. 4 is a side elevational view;

FIG 5 is a partially sectional side view, showing the material margin running over the positioning blade and under the tongue;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 5, showing how the plate undercut section and tongue are vertically spaced to define a shallow guide slot for the marterial margin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, FIG. 1 shows a presser foot 10 for binding the edge of a material with overedge stitching often referred to as overcast or overseam stitching. Presser foot 10 includes a main body or plate 11 which has a pair of laterally spaced bosses or lugs 12 and 13 thereon formed with coaligned openings for receiving a pivot pin that pivotally connects the presser foot 10 to a connector element or shank 14. The top of shank 14 is formed with a socket for receiving a presser bar or slide bar 15 that is connected to a household zigzag sewing machine (not shown). Slide bar 15 and shank 14 may be securely coupled together by tightening a conventional set screw 16. A conventional needle bar 17 carries a needle 18 that is movable in a typical zigzag path to draw stitching thread 19 through the material whose edge is being stitched. Extending between the leading or forward edge 20 of plate 11 and a needle opening 21 that accommodates the zigzag movement of needle 18 is a slot 22 which divides the forward region of plate 11 into a pair of laterally spaced forwardly extending arms 23 and 24.

An inner wall portion 25 of arm 23 constitutes a substantially vertical edge guide 'wall that is flat and straight with respect to the anticipated direction of the path of movement of the material under the presser foot 10. Guide wall 25 is shaped and located so as to make continuous flush sliding engagement with the edge of the material that is being overedge stitched. By keeping edge guide wall 25 in engagement with the raw material edge during stitching, mutual alignment between the material edge and presser foot 10 is assured so that otherwise crooked and unsightly completed edges are avoided. In addition, edge guide wall 25 serves to lay down and precompress randomly oriented fibers of the raw edge so that their tendency to ravel is decreased. In order to smoothly place the material edge against edge guide wall 25, positioning means is provided characterized by a generally horizontal positioning blade 26 that is preferably integrally connected to the lower edge of guide wall 25 and extends inwardly toward opposing arm 24. The positioning blade 26 provides a smooth angular transition between the vertical guide wall 25 and a horizontal surface defined by the upper surface of the positioning blade 26 to prevent snagging of the material edge.

As shown in FIGS. 1, 2 and 3 positioning blade 26 extends beneath the forward section of arm 24 to define therewith a shallow entrance passageway 27 (as shown in FIG. 4) through which the material margin is continuously fed during stitching. The forward portion of arm 24 is curved forwardly and upwardly to provide mal plane of the material which overlies a table or platform 29. As distinguished from lifting the raw edge into engagement with an edge guide wall such as guide wall 25, conventional edge guides are mounted on an external presser foot side and lowered beneath the flat undersurface of the presser foot where they constitute obstructions that can delay the stitching operation and, as previously mentioned, either must be adjusted to accommodate varying material thicknesses or are severely restricted to materials within a limited range of thicknesses. Guide wall 25 and blade 26 do not require adjustments and no portion of either of them depends below the fiat undersurface portion 30 of plate 11. The undersurface portion of blade 26 is preferably flat and arranged in substantially coplanar relationship with plate undersurface 30 to assist undersurface 30 in pressing material 28 against platform 29.

Referring to FIG. 2 and FIG. 5, plate 11 is integrally formed with a flat rearwardly projecting tongue 31 that symetrically bisects needls opening 21 and terminates in a free end 32. End 32 is disposed beneath a recessed or undercut section 33 formed in fiat undersurface portion 30. Under cut section 33 and tongue end 32 are vertically spaced from one another to define a shallow guide slot 34, best shown in FIG. 6, through which stitching loops pass. The zigzag action of needle 18 stepping alternately between the divided sections of needle opening 21 draws stitching thread 19 laterally across the preferably rounded top surface of tongue 31. Stitching loops slip reanvardly over tongue 31 and through guide slot 34 to eventually stitch the material edge in the desired manner. Tongue 31 is positioned and shaped so that when the stitches are woven into the material edge they will be sufiiciently taut to effectively bind the edge fibers and prevent them from ravelling and yet not taut enough to promote ridging or curling of the edge. The undersurface of tongue 31 is flat and arranged in substantially coplanar relationship with the undersurface of plate 11 and blade 26 to assist them in holding material 28 steady during stitching.

It will thus be clearly seen that during overedge stitching the positioning blade 26 and edge guide wall 25 coact to maintain continuous mutual alignment between the material edge and presser foot 10 as tongue 31 releases stitching loops under the optimum tautness so that the finished stitched edge is continuously smooth and free of ravelling, ridging, and curling.

What is claimed is:

1. An over edge presser foot capable of being attached to a zig-Zag sewing machine comprising:

a plate having forward and rearward edges and a flat undersurface portion, the plate being adapted to overlie the marginal edge of the material to be stitched;

means forming a needle opening through the plate for accommodating the zig-zag stitching motion of a needle;

spaced arms defined by a slot disposed between the plate forward edge and the needle opening;

a straight guide wall constituted by an inner wall portion of one of said arms;

a positioning blade connected to the lower edge of the guide wall to provide a substantially smooth angular transition between the guide wall and the blade, the blade being arranged to slide beneath the material margin to position the material edge against the guide wall to maintain continuous alignment between the material edge and presser foot during over-edge stitching; and

a tongue connected to the plate extending rearwardly into the needle opening, the tongue terminating in a free end positioned so that stitching loops can freely slip therefrom to neatly bind the material edge.

2. The structure according to claim 1 wherein:

the undersurface of a plate section located immediately rearward of the needle opening is undercut and 5 the tongue extends beneath the undercut section to define therewith a shallow guide slot through which the stitching loops pass; and

the undersurface of the tongue is in substantially coplanar relationship with the plate flat undersurface portion.

3. The structure according to claim 1 further comprising:

a connection element pivotally connected to the plate,

the connection element being dimensioned for connection to the sewing machine.

4. The structure according to claim 8 wherein:

the forward portion of the other arm curves upwardly over the blade to define therewith a shallow entrance passageway through which the material margin is continuously fed to a location beneath the needle opening.

5. An overedge presser foot capable of being attached to a zig-Zag sewing machine comprising:

a plate having forward and rearward edges and a flat undersurface portion, the plate being adapated to overlie the marginal edge of the material to be stitched;

means forming a needle opening through the plate for accommodating the zig-zag stitching motion of a needle;

spaced arms defined by a slot disposed between the plate forward edge and the needle opening;

a straight guide wall constituted by an inner wall portion of one of said arms;

positioning means arranged adjacent the guide wall for positioning the material edge in engagement with the guide wall which then operates to maintain continuous alignment between the material edge and presser foot during overedge stitching; and

a tongue connected to the plate extending rearwardly into the needle opening, the tongue terminating in a free end positioned so that stitching loops can freely slip therefrom to neatly bind the material edge.

6. The structure according to claim 5, wherein:

the undersurface of a plate section located immediately rearward of the needle opening is undercut and the tongue extends beneath the undercut section to define therewith a shallow guide slot through which the stitching loops pass; and

the undersurface of the tongue is in substantially coplanar relationship with the plate flat undersurface portion.

7. The structure according to claim 1, wherein:

the guide wall is fiat and generally perpendicular to the plate flat undersurface portion.

8. The structure according to claim 5, wherein:

the guide wall is flat and generally perpendicular to the plate undersurface portion.

References Cited UNITED STATES PATENTS 2,478,073 8/1949 Antonelli 112151 2,699,743 1/1955 Hill 112151 X 2,950,696 8/1960 Miller 112-235 3,304,896 2/1967 Laidig 112-235 3,370,559 2/1968 Longcore 112-235 PATRICK D. LAWSON, Primary Examiner mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,5l2,490 Dated May 19 1970 Inventor(s) David Wener It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 12, after "claim",

Delete "8" and substitute therefor l-.

SIGNEB'ANU- SEALED ISEAL) A teat:

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