US786923A - Process of forming tubes. - Google Patents

Description

UNITED STATES Patented April *11, 1905.

PATENT OFFICE. e

LESTER C. SMITH, OF ROME, NEW YORK.

PROCESS OF FORMIING TUBES.

SPEQIFICATION forming part of Letters Patent No. '786,923, dated April 11, 1905.

' Application filed August 10, 1903. Serial No. 169948.

TO all whom 't may concrn:

Be it known that I, LESTER C. SMITH, of Rome, in the county of Oneida and State of New York, have invented certain new and useful Im provements in Processes of Forming Tubes; and I do hereby declare that the following is a full, clear, and exact description of the inventiou, which will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form part of this specification.

The object of my invention is to provide a process of forming tubes from strips of sheet material in four passes through rollers.

In the drawings, Figure 1 shows a transversed section of the strip of material to be operated upon. Fig. 2 shows the same at the completion of the first operation. Fig. 3 shows the same after the second operation. Fig. 4: shows the same after the third pperation, and Fig. 5 shows the completed tube after the fourth operation.

The important point to be accomplished in forming tubes by the method herein set forth (or for that matter by any method) is to have the meeting edges of the strip so closed that any tendency to spring apart is obviated, and the meeting edges, in fact, press against each other with considerable pressure instead of having the tendency to spring apart or separate.

In carrying out my process of forming tube the first operation consists in turning in the edges of the strip to a circle substantially the same as that of thecompleted tube and as indicated at a a. The second operation con- Sists in giving a comparatvely sharp transverse bend to the strip through the middle and forming the middle to a circle, as indi- 'cated at b, less than that of the completed tube. The third operation consists in closing the tube into a substantially oval form with the meeting edges in the larger end of the oval. The final operation consists in forming the last-mentioned oval tube into a circular one. The tube thus formed Will have the edges pressing against each other instead of springing apart and in proper condition for soldering or brazing the two meeting edges together toform the closed pipe.

By the process herein described a tube of the character mentioned may be formed Without the useof a mandrel or core around which to operate.

What I claim as new, and desire to secure by Letters Patent, is

The process of forming a tube from a strip of sheet material in four Operations, which consists, first, in turning in the edges of the strip to a curvature substantially that of the i circle of the completed tube; second, in bending the strip along the middle to a curvature less than that of the circle of the completed tube; third, closing the tube into an oval form with the meeting edges in the large end of the oval, and, fourth, forming the last-mentioned form into a circular form, substantially as set forth.

In witness whereof I have afi ixed my signature, in presence of two witnesses, this 4Eth day of August, 1903.

LESTER cfsMITH.

, Witnesses:

H, J. ROWLAND, JOHN E. BIELBY.

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