US975383A - Process of manufacturing car-wheel blanks. - Google Patents

Description

H. R. KEITHLEY.

Patented Nov. 8, 1910.

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HERBERT R..- KEITHLEY, F KANSAS Y, MISSOURI;

PROCESS 0F MANUFACTURING CARWHEEL BLANKS.

To all ivhom 'it may concern:

Be itknown that I, HERBERT R. KEITH- Lex', a citizen of the United States, residing at Kansas City. in the county of Jackson and State of Missouri, have invented certain new and useful Improvements in Processes f Manufacturing Car-Viheel Blanks, of which thefolloiving` is a full, clear, and exact description.

In the present state of the art, it is impracticabie-to produce economically, sound and efficient car-wheels from steel castings or cast blanks, on account of the great difficulty of securing a homogeneous and solid structure 'in the cast blank. As a consequence the blank from which the car-Wheel i-s made must: be subjected to a previous rolling or forging operation before being subjected to the pressure of the dies Which give vthe blank the rudimentary form of a carivheel, and therefore the initial heat of the blank, due to casting, cannot be' retained until the initial die forging 'operation is erformed and the blank is required to be reiieated. This necessity of re-heating the blank vafter it has lost its initial heat due' to casting, limits the carbon content and con,- seqnently th 1 hardness of the steel-Which can be used in present methods ofproducing carwheels, to such an extent that comparatively lsoft steel is used. This isprincipally due to the fact that the harder steel must not, on account of its higher carbon content, be heated as highly and must therefore be forged at la lower temperature. At such lower temperature the resistance lof the harder steel to4 forging pressures increases more rapidly `with declining temperatures than it does with` mild steel.- its a consequence if harder steel were usedin'I order tol give it the degree ezt-plasticity required for the heavy forging pressures ofthe initial die'forging operation, itvvouldhave to be heated to a high 'temperature y at-Which there would be danger of over-heating or-lournin the steel. in my improved process this difficulty is'obviated by my method of producing a sound homogeneous steel cast blank which may be removed from the moldA to the dies andeuhjected to the initial die forging operation while it retains its initial heat dueto 'casting'9 and While` it retains a high degree of plasticity Which'coiild not be attained by rfa-heatingl the 'blank without Specification of Letters Patent. Y

ldanger of overheating and burning hard steels having high carbon content or hard steel alloys. The 'more especial object of my invention 1s to provide new and improved processes of manufacture Which will make hard steel :vnd its alloys, and preferably manganese steel, available and their use practicable and economical for producing car-wheels for railroad cais.

Manganese steel containing from G to 12 per leent. or more, of manganese possesses properties-of intense hardness and great resistance to abrasion and Wear. These qualities are essential in the Wearing body portion of the rim and flange of a car-Wheel for railroad cars. i

Heretofore manganese steel has had only a limited use for car-Wheels for mine cars, and could only be'adapted for this use by casting the manganese steel Wheel With a soft steel hub portion in Which the axle hole could be cored and finished by machining or could be bored out. For the' manganese steel, owing to its intense hardness, is 'practically uninachineable and cutting or boring tools have no effect upon it. As a conse-v quence of the difficulty of finishing this steel which can be done only by a grinding operation, it is iinpracticable to produce, with economy, carwheels from manganese steel by present processes of manufacture,

yIn carrying out my invention l produce, -bycasting, a blank of preferably circular form and substantially uniform thickness and of less diameterthan the finished Wheel v it is to form, and free from pipings, blow holes and other imperfections, and while hot the blank may .then `be removed from' the jmold and subjected to the heavy forging pressure of the initial die forging operation which produces the 'rudimentary hub, web `and rim of a car-Wheel in the blank, While it retains the initial heat due to casting. l In the accompanying drawings, illustrating my invention, in the several lires of vwhich like parts are'similarly designated, Figure l is a vertical sectional view showing a mold of special construction for producing steel cast blanks, according to m invention, which will be freefrom ipes, lowholes, shrinkage cavities, and ot ver defects., and from which car- Wheels may be produced according to my invention. Figt 2' is a lverllatented Nov'. 8, 19MB..

Application filed August 19, 1909. Serial No. 513,701.

cast blank partly forged by said dies, so as to form the rudimentary hub, web and rim portions of a car-wheel according to` my iuvention. Fig. 4 shows the partly forged steel castblank in vertical section, when removed from the dies, Fig. 3.

Referring to the accompanying drawings in detail, the steel cast blank C1 Fig. 2, is formed with a horizontal circularbody pory-tion and a vertical column portion having greater 'thickness and is. preferably'cast in a specially yconstructed mold, Fig.- 1, in

.which the cope A and drag' B'. are made of castironand-the riser Al-is preferably made "of sand or Ifire clay or similar refractory or heatzfretaining material'. Thismold forms a circular chamber C with 'a wide opening,

formed by the riser A1.' When the molten ysteel is poured into thezchamber C themetal in'contact with the cast iron chills A and B '-fsolidiies`-much more rapidly than in the central portions c1 c1 and the thicker column portion al in the riser A1, the layers of solidified metal formed each minute after 'the metal is' poured are indicated by the dotted lines .1. 2. 3., Fi 1. TheV outer portions of the steel cast b ank are rapidly contracted by contact 'with the chills A and B and exert such great'pressure inwardly upon the still Huid metall of the interior lower portions o1 a? of the casting that no pipes o1 l shrinkage cavities will vform in the lower interior portions of thel casting. The hydrostatic pressure of the Huid metalin the riser A1 will feed the fluid metal into the-interior fluid portions 01 cl'until the-entire lower part of the casting is solidied 'and all pipes, shrinkage cavities and other'defects will be .forced into the riser A1 and the=column of metal containing these defects can be discarded by cropping off when the casting is removed'from the vmold, leaving the whole lower portion of the casting in the form of a circular blank, sound and free from all defects and' ready for forging into a4 carwheel. The cope A ispreferably supported upon 55 two cams b1 b'carried by the'shaft b2; to

Which the lever b3 is-attached. vWhen the molten steel is `pourcd'intov the chamber C the portion in contact with the" cast iron cope A will` tend to shrinkdown' from the casting, and in order to prevent the forming of a space 'between the cast-in fand the co e A in which" gas .bubbles mig leverb3 is operated to turnthe cams b1 b1 on the shaft b2 so the weight of the cope A will continue to .rest directly upon the 5 metal as it solidiies anditends to' shrink t collect, t e5 away from the cast iron cope A. By thismeans the blank will be uniformly chilled both from the -top and the bottom and the casting will be' given a uniform structure.

Although the cope and drag of the mold are described above as preferably constructed of cast iron, sand, fire clay or other refractorymaterial may be used if desired. The steel cast blank when produced from manganese steel or similar hard steel alloy is preferably removed from the mold and the discard cropped off and then forged in the first operation forging'dies, Fig. 2, while still retaining its initlal heat from casting. By thi'smethod the hard steel can be subjected to the heavy pressure of the initial die vforging operation at muchfhigher' temperatures and consequently when in a softer andmore' plastic state than would be practicable if it were :necessary to re-heat the blank. 1

The cast blank C1 is forged 'in the dies D. E., Fig. 2,- Which are operated by hy- Adraulic pressure, thus formino' the rudimentary hub portion c1 I l with the hub portion c1 on onevside 1 of the' webc2 c2 and the annular concave cavity c4 producing the rim portion c3 c3 and the web 7 portion c2 c2 of a car-wheel, Fig. 3, by pressure betweenthe die portions' e2 e? d2 (Z2.

lfVhen the partly forged blank, Fig. 4 is removed 'fromtherst forging dies D. E., Fig. 3, it may be subjected to further forging or rolling operations to complete tho wheel. y

It is obvious that car-wheels may be produced 'according to my invention from other hard steel alloys 'than manganese steel, which are unmachineable', also from `soft steel. y

In all steel car-Wheels at'pre's'ent produced by forging the wheel into shape in order to give the required ductilityto the steel the and web .02, Fig. 3,

' is formed in the hubv .portion cl'by means of i .the annular convex 'projection d?.

from a'blan ,l'm'ade according to my invention the wearing 4body of the wheel rim can be made as lightlas the-ri'rnof a chilled cast iron car-wheel with a corresponding economy in weight and cost of metal.-H

erases.

than it would be practicable to re-heat a cold lilank to, for forging hard steel alloys or steels pf higher carbonv content thannoiv used for producing car-Wheels, and with this operationof'retaining the initial heat of the metal, from feasting, and raising it to a higher temperature after the removal of the i blank from the mold, which is involved in my process, all danger of overheating or' burning the steel Will be bviated.

In a ear-wheel produced from a blank made according to my invention the metal may be subject-ed to heat-treatment, if required, when the Wheel is forged into shape by heating it to a propertemperature and then suddenly cooling the metal by quenchin e. However itis believed that the chillingv effect of the metal forging-dies will. be sufficient lto give the toughness and tensile strength desired for manganese steel, without re-heating the forged wheel to temper it. over-heating and cracking the metal by relie-ating will be obviatcd.

I claim as my invention and desire to secure by\ Letters Patent- 1. Tlie method of producing an individual car wheel blank `free from pipes and segregations which consists .in casting a horizontal steel disk with `a vertieahcolumn rising fromthe top thereof, the parts being so proportioned that; tylie-v` metal. in"` the column remains fluid kuntilthe disk has solidified and the solidification of the disk `progresses from the edge thereof towardlfthe column, and then discardingathe coluifn.

2. The method o f producingan individual lcar Wheel blank free from pipes and segregations which consists in cast-inigr a horizontal steel disk-With al vertical column of considerable crdss-sectional area rising from the top thereofat the center, the column being so proportioned ythat theanetal therein remains fluid until the disk has solidified and the disk being so shaped that solidiication thereof progresses from the edge toward the center so as'to avoi'dthe formation of solidified portions in the disk between the `fluid column and unsolidified portions of the disk, and then discarding` the column.

3. The method of prdiicing an individual c'ar Wheel blank free from] pipes and segregations"-'Wliich consists in c'astinga horizontal steel disk whichrises gradually toward the center and there merges into a vertical column extending directly upwardly there'- from, the parts being so proportioned that Ithe column remains fluid until the disk has solidified, and solidification'of the disk pro- 4If this result is attained all danger of -gresses from the edget-hereof .toward the center, and then discarding the column.

4. The method of producing anindividual car Wheel'blank free from' pipes and segregations Which consists in casting a horizontal steel disk with a vertical column rising from the :top thereof, the parts being so proportioned that the metal in the columnci'emains fluid until thedisk has solidified and the solidification of'the disk progresses from the edge thereof toward the column, subjecting the disk to pressure while it is solidifying, and then discarding the column. 5. The method of roducing an individual car Wheel blank which consists in casting a horizontal shallow' steel disk which rises gradually from the edge toward vthe center and there merges into a vertical column extending upwardly therefrom, the parts being so proportioned that the column remains iuidl until the disk has solidified and solidiication of the disk progressing from the edge thereof toward the cen-ter, vand then discarding the column.

6. The method of manufacturing an individual car wheel blank which consists lin casting a blank iii such form as to cause l solidification of the metal to take place lprogressively from the entire outer surfaceto- Ward a common point so as to subjectv the progressively decreasing mass of molten metal in the interior of the blank to coinpression toward said point, providing a vertical column of metal at said point so as to produce al hydrostatic head of metal acting upon the molten interior of the blank. and maintaining a portion at least of the column in a fluid condition until ythe blank has solidified.

7. The method of manufacturing an individual car Wheel blank which consists in casting a blank in such form as to cause solidification of the metal to take place p rogressively from the entire outer surface toward a common point so as to,.subject the progressively decreasing' mass of molten metal in the interior of the. blank to conipression toward said point., providing avertical columii of metal at said point so asto produce a hydrostatic head of metal acting upon the molten interior of the blank, and causing the column to solidify more slowly than the blank.

S. The method of manufacturing an individual ear Wheel blank which consists in casting a blank in such form as to cause solidification of the metal to take place progressively from the entireouter surface to- Warda `common pointso as to subject the .progressively decreasing mass of molten column being made suiiciently large in cross section to cause the central portion thereof to remain iuidV until the blank has solidicd.

9. The method of producing an individual car wheel blank which consists in making a casting of molten steel having a much I from the top and bot-tom toward the interior and subject the progressively decreasing molten mass in the interior of the casting to compression stresses which, together with the hydrostatic head Of molten metal in the column, serve to compact the metal as it solidiies and at the ysame time permit the pipings and segregations to escape into' the column. i l c l .10, The method` of producing an individual car wheel blank which consists in casting a blank of substantially uniform vertical thickness .and having a much greater horizontal thickness than vertical thickness, providing a vertical column which rises rom the top of the blank, and chilling the blank, from the top and bottom faces so as to cause the solidilication of the molten metal to take place progressively from the. top and bottom faces of the blan, and .causing the flJlullpn to solidify more slowly'- than the 11. The method of manufacturing an iiidividual car Wheelblank which consists in making a casting of molten metal, chilling the casting from the top and bottom faces and from the sides so as to cause the casting to' solidify progressively from the entire Outer surface towarda common point and thereby subject the progressively decreas-- ing mass of molten metal in the lnterior of the casting to compression toward said point,

' more slowly than t-he casti 12. vThe method of pr ucing an indi' vidual car wheel blank which consists in making a casting in the form of a horizontal diskvhaving a much greater diameter than during cooling.

causing the column to solidify vertical thickness, subjecting the top Vand bottom faces and the periphery of the disk to a chilling action so as to cause the molten metal to solidify progressively from the Outer surfaces of the disk toward the center of the disk and thereby subject the progressively decreasing mass of molten metal in the interiorof the disk to. compression tO- ward the center, providing a vertical column of metal rising from the top of the disk at t-he center thereof so 'as to produce a hydrostatic head of metall acting upon the molten interior of the disk, and causing the metal ofthe column to solidify more slowly than the metal in the disk.

13. .The methodof producing an individual car wheel blank which consists in making a casting of molten metal, providinga vertical column extending upwardly from the top of the casting, chilling the rim portions of the casting and also portions be-- -to compression stresses coperating with the hydrostatic head of the molten metal in the column to compress the molten interior of the blank, and causing the column to solidify more slowly than the casting.

14. The method of manufacturing an individual. carwheel blank which consists in vcastinga blank having a much greater horizontal thickness than vertical thickness, chilling the blank from the top and bottom and from the sides so as tO cause the metal to solidify progressively from the outer surfaces to a common point and thereby subject the progressively-decreasing molten mass in the interior of the blank to compression toward said point, maintaining a Vertical .column of molten metal rising directly from the top of the blank at said point so as to subject the molten interior of the blank to a hydrostatic head Aof molten metal, and subjecting the lblank to external pressure In testimony whereof I hereunto set my hand this eighth day of May, A. D. 1909.

HERBERT R. KEITHLEY.

Witnesses:

.JOHN S. COOPER,

S. A. BISHOP.

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