US992463A - Process for manufacture of steel rings. - Google Patents

Description

L. P. WHITAKER. PROCESS FOR MANUFACTURE OF STEEL RINGS.

APPLICATION FILED APR. 20, 1910.

Patented May 16,1911.

F/ZZB.

UNITE STAE PATENT OFFICE.

LOUIS P. WHITAKER, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO S. DRESSER MANUFACTURING COMPANY, OF BRADFORD, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.

PROCESS FOR MANUFACTURE OFiSTEEL RINGS.

Specification of Letters Patent.

' Patented May 16, 1911.

To all whom it may concern:

Be it known that I, LoUIs P. W HITAKER, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain'new and useful Improvements in Processes for the Manufacture of Steel Rings; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention consists in a process for the manufacture of rings from steel or other wrought metal, and particularly for the manufacture of steel clamping rings for rubber packed pipe couplings, and said invention is illustrated in the accompanying drawing forming part of this specification and isfully disclosed in the; following description and claims.

In the accompanying drawing, Figure 1 represents a blank for the ring. Fig. 2 represents the blank bent into ring form preparatory to welding. Fig. 3 represents a section of tie completed ring.

The object of my improved process is to produce a wrought metal ring (preferably of steel) in which the molecules are in an inequiaxed condition, thus setting up internal stress and raising the yield point of the metal of the ring and producing a ring which will stand much greater stress before yielding than a ring o the same size and cross section formed of metal in which the molecules .are in the ordinary or equiaxed condition. 1

In carryin out my invention-I first produce a bar of substantially the cross section which is desired in the finished ring. The clamping ring which it is the special object of my improved process to produce, is provided? with an annular flat member, which I term for convenienceof reference,

the plate member, and from which an annular flange member extends on one side of the plate member, the said flange member having its base located between the inner and outer edges of the plate member. In carrying out the first step of the process I, therefore, first produce a bar, having in this instance a flat plate member, and a perpendicular flange extending from one side of the same, and located between the lateral edges of the plate member, thus havmember of which is indicated at 2.

ing in cross section something of the appearance of an inverted letter T. In Fig. 1, I have shown such a bar, .the. late member of which is indicated at 1, an the flange practice the flange 2 is located nearer. that edge of the plate member which is to form the inner edge of the ring, here indicated at 3 and the plate member is preferably made slightly thicker adjacent to the'edge 3 than it is adjacent to the opposite edge 4, and preferably diminishes slightly in thickness from the intermediate flange member 2 toward the edge 4. This bar may be formed in any one of several ways, as by rolling it in the desired form, or by planing it to the desired form,-or in other ways .which will suggest themselves to the skilled mechanic. The previously formed bar is then cut to the desired length, such as when bent into ring form, will produce a ring of the desired diameter. The bar or blank so formed is then bent into ring form in the plane of the plate member 1 thereof, below such temperature as will permit the molecules of the metal which will be forced into an inequiaxed condition by the bending operation. to return to the equiaxed condition and thereby certain internal strains are set up within the bar. It is known that above a certain temperature, which for convenience may be herein designatedthe critical temperature and which may be described with suflicient definiteness as a red heat visible in daylight, the molecules of steel remain equiaxed (or having all their axes equal), during the changes in the form of the material. If, however, a bending operation for example is performed upon a bar of steel at any temperature below the critical temperature the molecules of the metal become inequiaxed, and internal stress is set up within the metal which raises the yield point, or elastic limit of the metal, and greatly increases its stiflness.

The metal blank or bar may-be bent or formed into ring shape as before described by any suitable means, and the operation is shape of a ring, with its ends brought together for welding. As shown the meeting ends of the bar are cut at substantially right angles to the bar, for the purpose of forming a butt weld, but they may be so formed as to produce a lap weld if desired. The welding operation itself is preferably performed electrically in a well known way so that only a small amount of the metal at each side of the weld will be raised to or above the critical temperature. It may, however, be performed otherwise, as by heating the meeting ends of the bar only, in a gas furnace, care being taken to raise a small portion only. of the ring at each side of the weld above the critical temperature.

As the effect of raising portions of the metal adjacent to the weld above the critical temperature is to permit the molecules thereof to return to an equiaxed condition,

the portions of the ring so afi'ected, are after the welding operation subjected to a compressing action or mechanical working, after the metal adjacent to the weld has cooled below the critical temperature, as by hammering or rolling after the metal has cooled below such critical temperature. This working of the metal again inequiaxes the molecules of the portion of the metal which was annealed during the welding operation,

and again sets up a condition of internal stress therein, thus making the portions of the ring adjacent to the weld substantially as stiff as the other portions of the ring,

The resulting ring, which is illustrated in Fig. 3 of the drawing, will be found to have much greater stifi'ness than a ring of the same weight and thickness of metal which is made by operations conducted while the metal is above the critical temperature. The ring is finished by perforating the outer portion of the plate member whilebelow the critical temperature (and preferably while cold) as at 5, 5 etc., to form bolt holes to receive the coupling bolts of a pipe coupling. As will be seen the plate or base portion of the bar 1 forms the annular plate member 1 of the rin ,and the flange member 2 of the bar forms t e annular flange member 2 of the ring (the edge 3 of the bar forming the inner edge 3 of the plate member of the ring and the edge 4 of the bar restored to an inequiaxed molecular condi-' tion by hammering or otherwise mechanically working the metal. In some instances I may employ a rolling operation between specially formed rolls for the purpose of restoring the annealed portions of the ring after welding, to an inequiaxed molecular condition.

What I claim and desireto secure by Let-- ters Patent is l. The herein described. process of producinga steel ring, which consists in forming a straight bar of steel of the desired section, bending the bar into ring form, at a temperature which will raise the yield point of the metal, welding the meeting ends of the bar, and mechanically working the annealed portions of the bar adjacent to the weld, after they cool below. the critical temperature to raise the yield point thereof.

2. The herein described process of making a steel clamping ring for pipe couplings, which consists in forming a bar of steel having a platemember and a perpendicularly disposed flange member, bending the bar in the plane of the plate member thereof into ring form, at a temperature which will raise the yield point of the metal, heating only the portions of the bar adjacent to its meeting ends to'a welding heat and welding the ends together, then mechanically working the portions of the ring heated above the critical temperature during the welding process, after they have cooled below said critical temperature to again raise the yield point thereof.

In testimony whereof I aflix my signature, in the presence of two witnesses.

. LOUIS P. "WHITAKER.

Witnesses:

J. K. Moons, Wu. F. Donn.

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