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Publication numberUS391994 A
Publication typeGrant
Publication dateOct 30, 1888
Filing dateMay 7, 1887
Publication numberUS 391994 A, US 391994A, US-A-391994, US391994 A, US391994A
InventorsWilhelm Von Flotow
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Wilhelm von flotow and hermann leidig
US 391994 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)


Patented Oct. 30, 1888..



N PETERS Pnowmw m nu Wnshinglon. ac.



SPECIFICATION forming part of Letters Patent No. 391,994, dated October 30, 1888.

Application filed May 7,1887. Serial No.237,504.

(No model.) Patented in Germany March 15, 1887, No. 42,139; in France Apiil 8, 1887, No. 182,751; in England April 9, 1887, No. 5,268; in Belgium April 12, 1887, No. 77,029; in Italy May 10,1887, No. 21,508, and in Anstriafiungary August 537, 1887, No. 18,195 and No. 19,235.

To aZZ whom it mag concern.-

Be it known that we, WILHELM VON FLorow and HERMANN LEIDIG, both subjects of the Emperor of Germany, residing at the city of Dantzic, in the Kingdom of Prussia, Empire of Germany, have invented certain new and useful Improvements in Drawing Seamless Metal Tubes, of which the following is a specification.

For this invention we have obtained patents in the following countries: in Belgium, No. 77,029, dated April 12, 1887; in England, No. 5,268, dated April 9, 1887; in France, No. 182,751, dated April 8, 1887; in Italy, No. 21,508, dated May 10, 1887; in Austria-Hungary, No. 18,195 and No. 19,235, dated August 27, 1887, and in Germany, No. 42,139, dated March 15, 1887.

The object of our invention is to draw in a cold state tubes the diameter of which decreases successively in offsets.

The invention consists in drawing a tube in a cold state successively through openings of decreasing diameter.

In the accompanying drawings, Figure 1 is a vertical longitudinal section of the blank for drawing a tube the diameter of which decreases successively in offsets. Fig. 2 isa similar sectional view of the blank tube prepared for the drawing operation. Fig. 3 is a similar sectional view of the tube after it has been drawn. Figs. 1 and 5 are similar sectional views of the tubes, showing the dies used and showing different methods of drawing the tubes.

Similar letters of reference indicate corresponding parts.

One end of the blank tube A is reduced in diameter to form the holding-lug z for the drawing-tool. The tube A is then drawn in a cold state successively through a series of dies, the diameter of the opening of each die being slightly smaller than that of the preceding die,

and so on, whereby a tube is obtained, as shown in Fig. 3, said tube having a series of annular offsets, a, and at each ofiset the diameter of the tube decreases slightly. The tube is not drawn entirely through each die, but through the first die it is drawn to within a short distance of the larger end. Through the second die it is drawn to within twice this length from the larger end, through the third die to three times the distance from thelarger end, and so on. The offsets on the inside and outside can then be turned or ground off.

As shown in Fig. 4, the dies B can be made tapered on the inside, so as to reduce the height of the offsets, or to make a tapered tube without offsets, the inclination of the several dies being alike.

If desired, a rod, D, (shown in Fig. 5,) may be inserted in the tube A in such a manner that the offset D at its free end rests against the front contracted end of the blank. By means of the head 0 pressure is exerted on the opposite end of the said rod and thereby the blank is drawn through the several. dies.

Having thus described our invention, we claim as new and desire to secure by Letters Patent The method, substantially as herein shown and described, of drawing tubes having succcssivclydecreasing diameters, consisting in successively drawing the different parts of the length of the tube through difi'eren't dies having openings of different diameters, substantially as set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4961576 *Nov 23, 1988Oct 9, 1990Sandvik Special Metals CorporationConstant wall shaft with reinforced tip
US5074555 *Apr 24, 1989Dec 24, 1991Sandvik Special Metals Corp.Tapered wall shaft with reinforced tip
US5294118 *Apr 15, 1992Mar 15, 1994Sumitomo Rubber Industries, Ltd.Golf club shaft
US5935017 *Jun 28, 1996Aug 10, 1999Cobra Golf IncorporatedGolf club shaft
US6117021 *Dec 24, 1997Sep 12, 2000Cobra Golf, IncorporatedGolf club shaft
Cooperative ClassificationB21K1/30