US3333623A - Method of making the eye portion of needles - Google Patents

Description

1, 1967 L. RECKNAGEL ETAL 3,333,623

METHOD OF MAKING THE EYE PORTION OF NEEDLES Filed July 8, 1966 FiG.2

FIG. 3

FIG.4 I

ERNST FISHCHER WALTER JAGER United States Patent 3,333,623 METHOD OF MAKING THE EYE PORTION OF NEEDLES Lothar Recknagel, Albrechts uher Snhl, and Ernst Fischer and Walther Jiiger, Suhl, Germany, assignors to VEB Zentrale Entwicklung-Konstruktion fiir Eisen-, Blechund Metallwaren, Karl-Marx-Stadt, Germany Filed July 8, 1966, Ser. No. 563,882 3 Claims. (Cl. 163-5) This invention relates generally to making the eye portion of needles and in particular in making the thread grooves bounding both sides of the eye.

In the known methods for making the eye portions of needles, the needles are clamped into a pressing device for press-forming the short portion of the thread groove and a part of the long thread groove. Thereby, the eye portion is formed in a non-cutting manner, except for the eye itself, which is then punched between the threaded grooves. However, rough edges on the eye portion do exist, and have to be ground and polished to yield a smooth surface. Furthermore, the total length of the thread groove has to be milled, since during the pressforming operation, only a part of the long thread groove is formed. The steps following the press-forming and punching operations are partly carried out manually, whereby the quality of the eye portion depends greatly on the skill of the person who carries out these operating steps. Hence, it is quite obvious that this mode of operation is time-consuming and uneconomical.

It is, therefore, an object of the invention to overcome the above short-comings by providing an eye portion without requiring any manual labor.

It is another object of the invention to provide a needle with an ideal eye portion which meets all qualifications of withstanding the high rate of speed prevailing in modern sewing machines, and simultaneously of protecting the thread, so that the possibility of thread breakage is substantially eliminated.

It is yet another object of the invention to make the eye portion in such a way as to eliminate all time-consuming grinding and polishing of whatever kind upon the surfaces of the eye portion, after the eye is formed.

For a better understanding of the invention, its operating advantages and the specific objects obtained by its use, reference should be had to the following description taken with the accompanying drawings in which:

FIG. 1 is a broken axial section of the eye portion of a needle formed by hitherto known press-forming and punching methods;

FIG. 2 is a similar section showing the ideal form of the eye portion formed in accordance with the invention;

FIG. 3 is a similar sectional view showing the result of the first press-forming steps upon the eye portion of the needle in accordance with the invention; and

FIG. 4 is a plan view of the eye portion formed according to the invention with resulting edge formations,

as viewed from above in FIG. 3.

FIG. 5 is a sectional view similar to FIG. 3, showing the eye portion after the last step of operation.

Referring to the drawings, the needle blank is clamped by a known clamping device (not shown) and its eye portion 1 is subjected to a known press-forming operation for simultaneously forming therein a short thread groove 2 and an opposite long thread groove 3.

3,333,623 Patented Aug. 1, 1967 According to present practice, the eye 4 is then punched through the needle in a simple punching press (not shown). This produces an eye which is a hole between the short thread groove 2 and the long thread groove 3, as illustrated in FIG. 1. The punched eye 4 therefore has, at best, sharp terminal edges, and may include an outwardly-extending burr. Thread rapidly passing through such an eye may be cut, roughened, or even destroyed. It is, therefore, necessary to smooth such edges. This is commonly done by the so-called thread polishing process, by means of a thread which is interspersed with emery powder. The operation is manually carried out, requires skill and is time-consuming.

According to the invention, the eye 4a of the needle is formed with walls 5 which are rounded into the short thread groove 2 and the long thread groove 3 of the needle. See FIG. 2. The rounding is effected in the following manner: In the same operation in which the thread grooves are press-formed, further depressions 6 and 7 are press-formed beyond the bottoms of the grooves, to which they are connected by rounded portions 8 and 9. Thus an eye web 10 of the metal of the needle is left between the grooves. A further press-forming operation shrinks the thickness of the eye Web 10 to such an extent that the remaining metal of the web can be cut away by a punch, leaving no edge.

As will be seen in FIG. 2, the rounded walls 5 of the needle eye 4a diverge from the short thread groove 2 to the long thread groove 3 and are rounded with a shorter radius where they join the short threaded groove than where they join the long thread groove. This is very easily effected in the further press-forming operation mentioned above, the press-forming instrument being designed to compress the eye web 10 so that the further depression 7 extends to a position closer to the longitudinal axis of the needle than does the opposite depression 6, in a manner well known to a diemaker. It will be noted that the depth of the long thread groove 3 over its longer extent axially away from the eye 4, is greater than the depth of the short thread groove 2. This facilitates high speed effective operation of the needle; and is again a matter of the design of the press-forming instrument.

The metal which is displaced during press-forming projects laterally as shown at 11 in FIG. 4, and may be removed by known non-cutting methods.

Finally, the long thread groove 3 may be further elongated by known mechanical non-cutting methods, and the needle may be automatically subjected to known surface treatment.

Thus, the present time-consuming manual grinding and polishing operations may be eliminated, and rapid and economical needle production may be achieved. Furthermore, needles produced in accordance with the invention are better adapted to the rapid succession of stitches of modern sewing machines; and they reduce frictional heat because of substantially friction-free thread guiding.

While the above description discloses a preferred embodiment of my invention is by no means to be limited to that shown, but only by the limitations of the following claims.

What is claimed is:

1. A method of making the eye portions of sewing machine needles comprising the step of press-forming opposite thread grooves in'the needle with further depressions beyond the bottom of said grooves to provide an eye web between the depressions, the step of further press-forming the eye web to shrink its thickness, and the step of punching out the eye web of shrunk thickness, whereby a needle eye portion is provided which requires no manual grinding and polishing.

2. A method as claimed in claim 1, wherein the further depressions are press-formed with rounded portions connecting them to the thread grooves.

3. A method as claimed in claim 1, including the step of displacing the metal from the thread grooves and the further depressions laterally of the eye portion, and the step of removing the displaced'metal by a non-cutting operation.

No references cited.

GRANVILLE Y. CUSTER, JR., Primary Examiner.

RICHARD J. SCANLAN, JR., Examiner.

Claims (1)

1. A METHOD OF MAKING THE EYE PORTIONS OF SEWING MACHINE NEEDLES COMPRISING THE STEP OF PRESS-FORMING OPPOSITE THREAD GROOVES IN THE NEEDLE WITH FURTHER DEPRESSIONS BEYOND THE BOTTOM OF SAID GROOVES TO PROVIDE AN EYE WEB BETWEEN THE DEPRESSIONS, THE STEP OF FURTHER PRESS-FORMING THE EYE WEB TO SHRINK ITS THICKNESS, AND THE STEP OF PUNCHING OUT THE EYE WEB OF SHRUNK THICKNESS, WHEREBY A NEEDLE EYE PORTION IS PROVIDED WHICH REQUIRES NO MANUAL GRINDING AND POLISHING.

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