US3082724A - Stitch formation - Google Patents

Description

March 26, 1963 J. M. wAsHBuRN STITCH FORMATION 2 Sheets-Sheet 1 Filed Dec. 29, 1958 fnvenor: John/MWLsh/burn #5M His At orne'ys March 26, 1963 J. M. wAsHBURN STITCH FORMATION 2 Sheets-Sheet 2 Filed Deo. 29, 1958 In ven/tor: JohnM Washburn,

United States Patent Office 3,082,724 Patented Mar. 26, 1963 3,082,724 STITCH FORMATION John M. Washburn, West Hartford, Coun., asslgnor t The Morrow Machine Company, Hartford, Conn., a corporation of Connecticut Filed Dec. 29, 1958, Ser. No. 783,397 Claims. (Cl. 112-269) This invention relates to stitch formation, and more particularly to an improved form of three thread overedge stitch particularly .adapted to join work material edges either when the plies of material are in superimposed relation or in a relationship that is established when superimposed plies of material with the stitching applied thereto are opened or hinged into a relationship wherein the fabric edges become what is commonly designated an abutted seam.

A primary object of the invention is to provide an overedge stitch for joining work material, the stitch being effective to maintain plies of material in abutted relationship even if one of the needle threads is broken.

Other objects and advantages of the invention will become apparent by reference to the following specification taken in conjunction with the accompanying drawings.

In the drawings:

FIG. l is a perspective view showing a partially completed seam to which stitching has been applied in accordance with the invention; and

FIG. 2 is a perspective view showing the stitch of the present invention with work pieces abutted.

The stitch 0f the present invention is formed from three continuous threads: needle threads 1 and 2 and covering thread 3. The threads 1, 2 and 3 may be formed into the seam by a two needle Merrow overedge sewing machine of the type manufactured by the assignee of this application; threads 1 and 2 being placed by the needles of the machine and covering thread 3 being manipulated by the loopers of the machine. To form a seam joining work material along an abutted edge, the work material is positioned, as shown in FIG. l, in two plies M1 and M2 which are superimposed upon each other with the edges to be joined in vertical alignment. Needle thread 1 is formed into a series of fabric penetrating loops such as 4, connected in series by runs such 4as 4. Each loop 4 extends from its open end or base at a penetration point 5 through the fabric, thence along the under surface of the fabric to a point beyond the fabric edge and thence upwardly to locate the closed end or bight o-f the loop adjacent the aligned edges ysubstantially in a plane coincident with that of the upper surface of the work material. Penetration points 5 lie along a line which is generally parallel to the edge of the work material, the line of penetrations being spaced from the edge of the fabric by a xed distance.

As will more clearly be apparent, the arrangement of threads at these points 5 of fabric penetration serves as an anchorage. A loop of needle thread 1 starts from a point of .anchorage 5 and extends directly through the Worn material, `but a loop of needle thread 2, as loop 6, has its open end or base located at a penetration point 5 and passes from there along the upper surface of the work material to a fabric penetration point as 10. These penetration points are laterally aligned with penetration points 5, since the thread placing needles of the two needle overedge machine are parallel to each other, and lie along a line parallel to the line of penetration points 5 but at a greater distance from the edge of the work material. Each loop 6 emerges from a fabric penetration 10 and continues along the under surface of the fabric to a point beyond the fabric edge ,and thence upwardly a sufficient distance to bring the bight of loop 6 into registering paired relationship with the bight of a loop 4. A straight run of thread 2, as 6', extends next to run 4 of thread 1 and from one penetration point 5 to another.

A third continuous thread 3, comprising a covering or locking thread, is formed into a series of loops 12 and runs 12. Each loop 12 is looped through the bights of a registering pair of loops 4 and 6 of threads 1 and 2 respectively and from this point extends obliquely over the upper surface of work material to the anchorage or penetration point 5 of the next succeeding registering pair of loops 4 and 6 where the bight of loop 12 extends around the bases or ends of adjacent loops 4 and 6 to maintain runs 6 of needle thread 2 in close relationship with runs 4 of needle thread 1.

When the previously superimposed plies of work material M1 and M2 are opened as a hinge into abutted relation as shown in FIG. 2 it is seen that loops 4 of thread 1 extend on the under side of the material directly from penetration points 5 in material M1 to penetration points S in material M2. Runs 4 of thread 1 are on the upper surface of work material M1. Also it is seen that the penetration points 10, 10 for loops 6 of thread 2 are, in respect to each ply of work material M1 and M2, laterally offset outside the alignment of penetration points 5, 5 respectively for loops 4 of thread 1. Loops 12 of thread 3 with their bights anchored .at penetration points 5, extend on the upper surface of both plies of work material and thence through registering bights of loops 4 and 6 included in a preceding unit of stitch formation. Inasmuch as the bight of loop 6 is anchored in its registering relationship with a bight of a respective loop 4 the position of penetration 10' in work material M2 becomes offset from the line of runs 12 of loops 12. This offset of penetration points 10 in material M2 is permitted by excess thread provided when the loops 6 are extended through the fabric plies when they are iu superimposed relation.

Because of the above described relationship, if either needle thread 1 or Z is broken, the other thread will hold the seam with the edges of plies M1 and M2 maintained in abutment.

The foregoing description is to be considered exemplary rather than limiting and the true scope of the invention is that defined by the following claims.

I claim:

1. An overedge chain stitch seam comprising a pair` of continuous needle threads for-med into two series of loops penetrating a piece of fabric at different distances from one edge of the fabric and having portions extending beyond said edge, and a covering thread formed into a corresponding series of loops interlooped with the loops of said needle threads yby extending through said portions of the loops of both needle threads and about adjacent loops of both needle threads at the points where the series of loops of that one of said needle threads closest to said edge penetrate the fabric.

2. An overedge chain stitch seam comprising a first continuous needle thread formed into a rst series of loops penetrating a piece of fabric at spaced points lying along a rst line spaced inwardly from an edge of said fabric, a second continuous needle thread formed into a second series of loops passing through said fabric at spaced points lying along a second line located between said edge and said first line, both of said series of loops having bight portion-s projecting from one surface of said fabric, the bight portions of each loop of said rst series being located adjacent the bight portions of a loop of said second series, and a continuous covering thread formed into a third series of loops, each loop of said third series being looped through adjacent bight portions of loops of said iirst and said second series and having bight portions looped around adjacent loops of said first and said second series on the opposed surface of said fabric at points of fabric penetration lying on said second line.

3. An overedge chain stitch seam comprising a first continuous needle thread formed into a rst series of fabric penetrating loops connected by runs of said first thread lying on one surface of a piece of fabric in generally parallel spaced relationship with an edge of said fabric, each loop of said first series extending from between adjacent runs of said first thread away from said edge and through said fabric at a penetration point and having a bight portion projecting from the opposite surface of said fabric at said penetration point and beyond said edge, a second continuous needle thread formed into a second series of fabric penetrating loops connected by run-s of said second thread lying on said one surface of said piece of fabric contiguous to and substantially co-extensive with said runs of said lirst thread, each loop of said second series passing through said fabric at a penetration point located between adjacent runs of said rst thread and having a bight portion projecting yfrom said opposite surface of said fabric beyond said edge into adjacent relationship with the bight portion of the adjacent loop of said first series, and a continuous covering thread formed into a third series of loops, each loop of said third series extending through the bight portions of adjacent loops of said first and said second series and across said one surface of said fabric beneath next adjacent runs and around the loops of said `first and said second series connected between next adjacent runs.

4. An overedge seam for-med `from two continuous needle threads and a continuous covering thread, said threads being interlooped With each other in regular succession adjacent one edge of a piece of fabric, each of said needle threads being `formed into a series of loops with the loops of one series extending through the fabric at points of penetration spaced further from Vthe fabric edge than points of penetration where the loops of the other series extend through the fabric, said covering thread comprising a series of loops with each loop looped through adjacent loops respectively of the two needle threads at a point adjacent the fabric edge, each loop of said covering thread having a bight portion looped about adjacent loops respectively of the two needle threads at a point in the line of needle penetrations nearer the fabric edge.

5. An overedge seam for joining portions of work material along a line Where two sections of material are in abutted relaitonship, the seam being formed from two continuous needle threads and a continuous covering thread, said .threads being interlooped with each other in regular succession adjacent the abutment line, each of the needle threads being formed into a series of loops with each loop of one series extending through the fabric on opposite sides of the line of abutment at respective points of needle penetration spaced respectively further from the line of abutment than corresponding points of needle penetration of the other series of loops, said covering thread comprising a series of loops with each loop looped through adjacent loops respectively of the two needle threads at a point on one side of the line of abutment and having a lbight portion looped about adjacent loops respectively of the two needle threads at a point in the line of needle penetrations nearer the line of abutment.

References Cited in the tile of this patent UNITED STATES PATENTS 811,789 Onderdonk Feb. 6, 1906 875,594 Onderdonk Dec. 3l, 1907 2,787,233 Walling Apr. 2, 1957 2,903,872 Ledwell Sept. 15, 1959 2,980,917 Slane Apr. 25, 1961 OTHER REFERENCES Federal Standard Stock Catalogue, Section lV, Part 5, March 4, 1930.

Claims (1)

1. AN OVEREDGE CHAIN STITCH SEAM COMPRISING A PAIR OF CONTINUOUS NEEDLE THREADS FORMED INTO TWO SERIES OF LOOPS PENETRATING A PIECE OF FABRIC AT DIFFERENT DISTANCES FROM ONE EDGE OF THE FABRIC AND HAVING PORTIONS EXTENDING BEYOND SAID EDGE, AND A COVERING THREAD FORMED INTO A CORRESPONDING SERIES OF LOOPS INTERLOOPED WITH THE LOOPS OF SAID NEEDLE THREADS BY EXTENDING THROUGH SAID PORTIONS OF THE

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