US1935121A - Needle for forming an ornamental seam - Google Patents

Description

Nov. 14,1933. HARMON 1,935,121

NEEDLE FOR FORMING AN ORNAMENTAL SEAM Filed May 12, 1928 WW4 V a/ Patented Nov. 14, 1933 NEEDLE FOR FORMING AN ORNAMENTAL Frank L. Harmon, Beverly,-Mass., assignor to V I United Shoe Machinery" 0orporation, Paterson, N. J., a corporation of New Jersey Application May 1928-. SerialNo. 277,175

' 2 Claims. (01. 112-224) The'present invention relates to a methodof forming an ornamental seam of stitches in shoe leather or similar material, and to a needle for use in practicing said method.

' The ornamental seam produced by the method of the present invention is of that type in which the portions of the stitches appearing on at least one surface of the work are separatedfrom each other, and are set at an angle to the line of stitching. To produce this type of seam, it is necessary to provide the sewing machine used in sewing the seam with a device, or devices adapted to make thread receiving perforations in the work in the form of comparatively long, narrow slits, arranged obliquelyto the line of the stitching. With thread receiving slits formed and arranged in this manner, thethread of each stitch, as it is set in the work, can be drawn to the ends of'the slits so that the-portions of the stitches remaining on the surface of the work connect the adjacent ends of the slits and thus give the desired effect.

For the production of an ornamental seam of the type above referred to a feature 'of the present invention contemplates inserting a hook needle through the work and simultaneously with said insertion, forming a needle and thread receiving slit in the work, obliquely to the seam.

, A slit of the proper length is thus formed in the work and the needle is forced through this slit by the action'of a single instrument and the work is perforated only once for each stitch, a clean out being made in the work and the thread being pulled through the work on the return stroke of the needle without the injury to the edges of the slit and the distortion of the material which would be occasioned by the use of an instrument separate from the needle for forming the slit. Preferably the slit made by the needle is at least as long as the greatest cross sectional dimensions of the needle, and also preferably the slit, as it is cut during the perforating stroke of the needle, is distended into the form of a perforation having a substantially square cross section, By cutting the slit at least as long as the greatest cross sectional dimen-. sion of the needle, a large thread as compared to the size of the needle, may be used without filling the slit sufficiently to detract from the desired appearance of the portions of the stitches appearing on the surface of the work. Also, the stretching of the slit into a perforation which is square in cross section permits the legs of the needle loop as it is pulled through the material to be drawn readily to the extreme ends of the slit without injury to the material and without excessive strain on the thread.

The improved needle which is used in practicing the method above described is constructed so as to be capable of performing the functions of both an awl and a needle, being shaped to form a thread receiving slit as it is forced through the work, and being provided with a thread receiving hook by which thread may be drawn "through the slit on the return stroke of the needle. In

order to form a slit in the work of the greatest possible length without increasing the size of the needle beyond the usual requirements for a designated size of thread and length of stitch, the needle is provided with a chisel edge formed on the greatest cross sectional dimension of the needle. The contour of this edge is preferably straight and at right angles'to' the direction 'of movement of the needle so that,close to the cutting edge, the needle is in the form of a thin blade, the sides of which are at the same angle to each other throughout the width of the blade. A cut in the work the full width of the blade is thus insured regardless of the yielding qualities of the leather or other material-being operated upon. In the illustrated construction, the needle has a cross section which is substantially square and the chisel edge is formed on one of the diagonals of this square. 'This construction has the further advantage,as comparedto the ordi' nary cylindrical needle, that the needle isen'abled to penetrate the work with a minimum of distortion of the material forming the edges of the cut, and the edges of the out are moulded in '"sucha way as to permit the thread'to be readily drawn to the ends of the out when the stitch is pulled into its final position. To permit a comparatively large thread to be drawn readily through the material, the hook of the needle is preferably formed in that portion of the needle which is taperedto form the chisel cutting edge.

The several features of the present invention will be clearly understood from thefollowing description taken in connection with the accompanying drawing in which Fig. 1 is a view in side elevation of the preferred form of straight hook leather sewing needle which mayv be used in practicing the method; Fig. 2 is a cross sectional view taken on the line 2-2 of Fig. 1; Fig.

3 is a view in front elevation of the needle illustrated in Fig. 1; Fig. 4 is a sectional view illus- LID trated in Figs. 1, 2, and 3; Fig. 5 is a plan view taken on the line 55 of Fig. 4; Fig. 6 is an underneath plan view of the chain stitch seam illustrated in Figs. 4 and 5; Fig. 7 is a view similar to Fig. 4, but illustrating a lockstitch seam; and Fig. 8 is a plan view of the lockstitch seam illustrated in Fig. '7.

The needle illustrated in Figs. 1, 2, and 3 of the drawing is a straight hook needle, the shaft or body portion 9 of which is substantially square in cross section. At its lower end, the needle is tapered to form a blade, the cutting edge of which, indicated at 10, extends diagonally of the cross section of the needle, and is of a length equal to the full diagonal dimension of the shaft of the needle. The sides of the blade, as they meet to form the cutting edge 10, are at substantially the same angle to each other throughout the length of the cutting edge so that a strong and serviceable cutting edge is provided which, when the needle is forced through the work, will make a clean cut the full length of the edge.

The hook of the needle is formed in the tapered portion of the needle so that the open eye 11 is located above the cutting edge 10, but below the body portion of the needle. This forms a strong and serviceable hook while leaving the cutting edge the full length of the greatest cross sectional dimension of the shaft of the needle, and at the same time, permits a loop of comparatively large thread, as indicated at 12, in Fig. 3, to be drawn through the work by the needle.

In using the needle illustrated in Figs. 1, 2, and 3 to form a chain stitch, as illustrated in Figs. 4, 5, and 6, the needle is arranged so that the cutting edge 10 stands obliquely to the direction in which the work is fed. The needle is forced through the work and forms a slit, as indicated at 13, disposed obliquely with relation to the seam which is to be formed. As the needle passes down through the work, the slit is expanded into a perforation having a cross section substantially square and corresponding to the cross section of the shaft or body portion of the needle. After the needle is through the work, the thread is laid in the hook and the needle is withdrawn pulling up a loop of thread as indicated at 14 and through a previously formed loop, as in the ordinary method of making a chain stitch with a hook needle. The workis now fed and the operation of perforating the work and drawing up another loop is repeated. The final result after the formation of a number of stitches is as illustrated in Figs. 4, 5, and 6, the

legs of the needle loops 14 on the chain side of the work being drawn outwardly to the ends of the slits, and the portions of the stitches, indicated at 15, on the opposite side of the work extending from the adjacent end of one slit to the adjacent end of the next slit. Due to the resiliency of the material and to the fact that the sides of the slits have not been unduly torn, stretched, or distorted, the slits, particularly on the single thread side of the work nearly or completely close up so that the final appearance of the seam on the single thread side of the work is as indicated in Fig. 6.

In forming the lockstitch illustrated in Figs. 7 and 8, the needle is actuated in the same manner as in the formation of a chain stitch to form slits in the work oblique to the seam, and to draw loops of thread through these slits. Instead of enchaining these loops, however, a locking thread 16 is passed through the loops and the loops are then drawn down to set the locks in the work as is usual in forming a lockstitch seam with two threads. As indicated in Figs. 7 and 8, thelocks are located substantially in the middle of the work so that the seam has the same appearance on both sides of the work, the portions of the thread on the surface of the work connecting the adjacent ends of the slits, and the slits intermediate their ends being wholly or partially closed to give the appearance indicated in Fig. 8.

The nature and scope of the invention having been indicated, and a manner in which the invention may be embodied and practiced having been specifically described, what is claimed is:

1. A. hook sewing needle for sewing an ornamental seam provided, at its work entering end, with a straight cutting edge extending completely across the greatest cross-sectional dimension of the needle and arranged at right angles to the length of the needle, and also provided with a hook near its work entering end formed by an eye opening on the side of the needle and extending transversely through the needle at right angles to the straight cutting edge.

2. A hook sewing needle for sewing an ornamental seam having a substantially square cross section tapered to form a straight chisel edge at the entering end of the needle extending diagonally of the cross section of theneedle at right angles to the length of the needle, and provided with a hook near its work entering end formed by an eye opening on the side of the needle and extending transversely through the needle at right angles to the chisel edge.

- FRANK L. I-IARMON.

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