US831031A - Process of producing solid drawn tubes. - Google Patents

Description

No. 831,031. PATENTED SEPT. 18, 1906.

' E. BIER & A. HOFFMANN.

PROCESS OF PRODUCING SOLID DRAWN TUBES.

APPLICATION FILED DBO.2Z,1905.

2 SHBETSSHEET 1 No. 831,031. 'PATENTED SEPT. 18, 1906. E..BIER & A. HOFFMANN.

PROCESS OF PRODUGINGjSOL I D DRAWN TUBES.

APPLICATION FILED DBO.22,1905.

2 SHEBTS-SHEET 2:

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UNITED STATES PATENT OFFICE.

EMIL BIER, OF MI ILHEIM-ON-THE-RUHR, AND ADOLF HOFFMANN, OF COLOGNE, GERMANY.

Specification of Letters Patent.

Patented Sept. 18, 1906.

Application filed December 22,1905. Serial No. 292,987.

To all whom it mayconcern:

Be it known that we, EMIL BIER, residing at Miilheir'n-on-the-Ruhr, and ADoLF HOFF- MANN, residing at Cologne, in the Province of the Rhine, Kin dom of Prussia, German Empire, subjects 0 the King of Prussia, German Emperor, have invented a new and useful Process for Producing Solid Drawn Tubes, of which the following is a specification.

The processes hitherto in use for the preparation of hollow blocks such as are used in industry especially for the purpose of rolling out and in the construction of seamless tubes and boiler-making are very complicated and costly. In general this operation has hitherto been effected by removing by mechanical means the up or end of the cast block, which contains airoles and flaws after it has cooled, then again heatin the block and driving the mandrel throng it by means of a press.

The ,new process for the production of solid annular cast blocks depends in principle on the circumstance that the material cast in a mold ta ering upward receives from its lower annufar surface an upwardlydirected pressure and is moved upwardly, while at the same time a tapering mandrel in the interior of the block, though compelled to follow the upward motion, receives a pressure from above in the direction opp0-. site to the pressure acting upon the lower an nular surface of the block which imparts to it a retrograde motionthat is to say, while the block is pressed up in the tapering mold for a certain height the mandrel rises to a lesser height. By this means the following advantage is obtained: The pressure exercised by the tapering wall of the mold upon the material while being raised compresses the latter to a high degree of density, and being transferred also upon the mandrel this latter is caused by friction to participate in the upward motion of the material. The shrinkin of the block would lead to a s litof t e same; but this is prevente by the retro rade motion caused, as stated, by a pressure cm above upon the mandrel. This motion is regulated specially in each particular case according to the strength of the block and its shrinking, so as to prevent any splitting of the cooling block.

Figure 1 of the accompanying drawmgs illustrates by way of example, partly in elevation and partly in section, a press which can be utilized for the carrying out of the process above set forth. Fig. 2 is a similar view showing the parts in elevated position. Fig. 3 is a diagram illustrating, respectively, the risin motlons of the metal block and of the man rel, the curves indicating how much the latter is gradually falling back.

In the drawings, a denotes the lower piston; b, the upper piston ;'c, the mold tapering upward, with a cylindrical part of the her ht d at its lower end. In the interior of t e mold there is placed the tapering-mandrel e, which is seated upon a thin sheetmetal disk f of exactly the same diameter as the cylindrical part of the mold. A loose piston 1 above piston a, filling this cylindrical part, is recessed at its upper face and counterbored centrally to receive the lower tenon' of the mandrel. By this means a closure against the material 9 is provided when it is poured in from above, and the retrograde motion h is assured, as the mandrel can recede into the recess of iston Z by shearing off the middle part of disk The mold c rests upon a ring z and this in turn upon a carriage k, which latter holds the piston Z, supportlng the disk f.

The press is shown in its initial position in the illustration, Fig. 1. The material 9 has been poured. The piston 12 has been lowered, together with a plate m, upon the taperin mandrel e. As soon as the liquid materia commences to harden hydraulic pressure is a plied to both the pistons a and 6 through t e tubes n and 0, whereby the following effect is attained: The lower piston a reaches the piston Z and carries it upward. This latter presses by means of its annular upper part upon the disk f, which conveys the pressure to the material in the mold. The up er piston b acts upon the tapering mandrel. fdy means of the pressure exercised by the annular part of piston l the material is forced upward in tapering shape. The walls of the mold exercise pressure upon the material, imparting to it a high degree of density. The tapering mandrel is caused to take art in the u ward motion, being held fast y the shriniiage of the material while cooling. This reaction, in case the mandrel rose in the same degree as the piston I, would cause a splitting of the material as it cooled further; but this accident is prevented by the retrograde mo- -m encounters the tion of the mandrel imparted by the upper The piston, which as it is smaller than the lower one, is at first compelled to rise, but by closthe pressure liquid beci ing up the opening 0 hind piston b is gradually compressed to recede or fall back. the apparatus so as to regulate the motion of the pistons according to the extent of the shrinking. Fig. 2 shows the press after the completion of the process. lhas traveled the distance p w. The upper piston has traveled the distance The disk f has been sheared ofi in the motion. The hollow block 9 is finished. The escape from the tube n, the pistons a and I return to their the upper piston is presse downward, and in its further course the plate finished block and pushes piston b is compelled It is easy to control The piston pressure fluid is then allowed to original position,

it out.

ically by means of curves. In F difierent blocks.

iston a. urther, 8 denotes and\t the time within which the process is completed. It will be seen from the curves without further explanation that the disretrograde motion.

tance m represents themea the predetermined curves which form the control diagram. the control mustbe conducted, and thus one has at any time an illustration of the condition of the process.

and the mold the duration of the process can be shortened as much as desired. The distance t will then be correspondingly reduced.

Having thus described our invention, What we claim is- Process for the production of highly-densified hollow metal blocks or ingots which consists in casting the metal into a taperin mold around a tapering of higher degree, solidify, the taper mold together with the taper mandrel to increase allowing the mandrel to retrograde during the motion, substantially as described and for the purpose set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing winesses motions of the piston are transferred by ns of a suitable indicating device upon According to these curves By cooling the mandrel mandrel or core 0 ta er then allowing the meta to then pressing the ingot axially into the density,

MIL BIER. ADOLF HOFFMANN.

In presence of

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