US1662506A - Method of rolling staybolt iron - Google Patents

Description

March 13, 1928.

s. H. MANSFIELD METHOD OF ROLLING STAYBOLT IRON Filed Nov. 25, 1925 WITNESSES .nated, I show in Patented Mar. 13, 1928.

UNITED STATES PATENT OFFICE.

METHOD OF ROLLING STAYBOL'I. IRON.

Application filed November 215, 1925. Serial No. {1,364.

This invention relates to new principles introduced to the rolling, hammering, pressing, or otherwise sha ing of hollow-staybolt iron or steel bars an has for one of its objects the working or rollin of a hollow bar froman original hollow pi e; another object being to produce such a bar substantially seamless, still another to materially increase the tonnage production from a given amount of fuel and labor and hence reduce the cost per pound.

Referrin to the accompanyin drawings, in which similar arts are simi arly desigigure 1 a cross-sectional view of a hollow ile of sectional iron bars arranged substantlally in the formation of a tube; in Figure 2 a steel mandrel designed to be used by insertion into the hollow pile to control the size and contour of the hole thereof; in Figure 3 an illustration of the manner in which the hollow pile is entered into the rolls of a rolling mill and of the manner of inserting the said mandrel; in Figure 4 a longitudinal cross-section of an iron container or tube containing a refractory core; Figure 5 a-hollow billet evolved fr am the said hollow pile, having-the core of Figure 4 inserted therein;.and in Figure 6 a finished hollow st-aybolt bar.

Proceedin to explain the invention in more exact etail, in the construction of the hollow pile of Figure 1 I employ, preferably, four sectional bars curved in such a manner that two of them butted against each other form a tubular shape and constitute the inner layer 2 of the hollow pile; after which a second or outer layer 1 is provided by enveloping the said inner layer 2 with similarly curved sectional bars. The hollow pile thus formed is charged into a heating furnace and brought to a welding heat, when it is removed from the furnace and rolled throughreducing rolls of a rolling-mill. Such rolls are illustrated in cross-sectional views 13 of Fig. 3, with collars 14. The 0 ration is offected b setting the heated ho low-pile u on a suitab e bed as indicated by dotted out ine 14, at which juncture an operative inserts mandrel 4 into hole 3 to an extent that mandrel-tip 5 reaches a location'within the pile exactly at a line centrally between the axes of rolls 13, whereu on another operative entore the pile into t e said r0115 13, resulting in reduction of its cross-sectional diameter as indicated at 20, while the hole 3 is correspondingly reduced 8 to the diameter of mandrel-tip 5. By provision of a fixed stop upon mandrel-bed l8 and a shoulder-plate 6 on mandrel 4, the'latter is prevented from accompanying the pile through the rolls, the rolls, in eli'ect, drawing the pile off the mandrel. Handle 7 is provided on the mandrel 4 for grasping by the operative. In Figure 3 is shown a partially cut-out section to clearly illustrate the longitudinal cross-section of said pile and the generous clearance space 3 between the mandrel 4 and inner layer 2 of pile, and which facilitates the entry of the mandrel 4. I may give the pile additional assages through the rolls over mandrels, eac number of such operations is governed by the outside and inside diameters which are desired in the finished bar. After the passages over mandrels, when the pile is thoroughly welded into an integral mass of iron, it has become an evolved hollow billet as shown at 15 of Fig. 5, into the hollow of which is inserted a core-bar of which a longitudinal cross-section is shown in Fig. 4,

consisting of a tubular container 9 holding a refractory 10, plugged 11 at the ends with ed es of container 9 bent over as at 12 to ho d securely the plugs 11. Again in Fig. 5 I show a partially cut-out section of billet 15 to illustrate the disposition of core-bar 9 within said billet 15, which thereupon is rapidly rolled down throu h the successive passes of ordinary rolling-mill. rolls to the desired diameter of the finished bar 16 of Fig. 6. In these reducing operations the core 10 is reduced in cross-section in proportion to the wall of the billet, evolving into a finished bar of relatively thick wall and small core 17, which latter may be extracted in any desired manner, such as drilling,ream1ng, or water or air pressure.

It is obvious that substitutes for the hollow pile may be used, such as drilled, pierced or forged masses of iron, and yet remaln within the scope of my inventlon embodying the combinatlon of the principles of the mandrels and the core.

'It is further obvious that the core is not restricted to the combination of a core within a container, as any core substance possessing an adequate heat-resistmg property and reasonably rigid form for convenient insertion into the hole of the pil e or billet, would "equall carry out the spmt of my invention. or must it be necessarlly a resuccessively smaller in diameter. The

fractory, since if a cold container be used,

and kept out of the furnace until the pile is drawn therefrom, it would be practicable to employ copper or any other metal or substance of fairly high heat-resisting property within the core container; or la 'ain, such copper bar may be used unencased, by squirting a stream of cold water through the hole of the )ile or billet to chill or materially reduce the temperature of the immedate inner wall to such an extent as will not melt the copper, which, retaining its solidity, would occupy its proportion of the crosssectional area in the successive operations of reduction. In the event of using such metallic core, I would preferably extract it from the finished bar by heat, as in an electric furnace, to a degree that the copper would melt and flow out, without, however, reachin the critical point of heat of the iron itsel.

It is further obvious that various core refractories can be used, such as silica sand, mica, fireclay, carbon, and the various products of electric or other high-temperature furnaces, such as earborundum, aloxite, siloxicon. calcined magnesite, et

My invention embraces the principle of exposing the unincumbered pile to the furnace heat, without core or anything what ever inside; thereby the entire inner surface, along with the outer surface, is exposed directly to the heat, which in effect saves practically 50% of the fuel required to heat a given tonnage of iron, hence achieving a wholly new condition of econ- It is obvious that various substitute core materials might be used by this method, such as hardwood, sawdust, etc., since, while such materials are combustible, yet the core-container 9 is ke t from the heated iron until inserted into hillet 15, thereby acting as a shield against heat reactions of the core.

It is also obvious that ice might be employed as a core, since the sole object of the core is but to momentarily preserve a relative rigidity and resistance of core-container 9 to the compressive action of the roll passes.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The method of making hollow staybolts which consists in assembling metal pieces to form a hollow pile, heating said pile, welding said pieces together and re ducing the cross sectional diameter of said pile in successive sta es, controlling the diameter of hole in tie pile with mandrels during the first stages of reduction and controlling the diameter of hole by a core in the last stages of said reduction, said core bein inserted in said pile while said pile is still hot. I

2. The method of making hollow staybolts which consists in assemb ing metal pieces to form a hollow pile, heating said pile, welding said pieces together and reducing the cross sectional diameter of said pile in successive stages. controlling the inner diameter of said pile in the first stages of reduction with mandrels and controlling the inner diameter in the last stages of reduction by a core, said core being inserted in said pile after said pile has been heated.

GEORGE HENRY MANSFIELD.

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