US1901035A - Method of making cold rolled disks - Google Patents

Description

March 1933- G. L. KELLEY Er AL METHOD OF MAKING COLD ROLLED DISKS Fl G. 2.

Filed June 2, 1928 INVENTOR. G- BUDD.

EDWARD EORGE KELLEY ATTO E Patented Mar. 14, 1933 UNITED STATES PATENT OFFICE GEORGE L. KELLEY AND EDWARD G.

BUDD, OF PHILADELPHIA, PENNSYLVANIA, AS-

SIGNORS 'IO BUDD WHEEL COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A GOR- PORA'IION OF PENNSYLVANIA METHOD OF MAKING COLD ROLLED DISKS Application filed June 2, 1928. Serial No. 282,441.

Our invention relates particularly to those methods of making wheel disks or articles susceptible of similar manufacture in which cold rolling is a principal part of the work done upon the blank. Work done by processes of combined rolling and spinning from sheet metal or thin plate is frequently used in such processes. In cases where the reduction of section is very great or relatively great as compared with the normal section of the blank, the gross amount of working of the metal is very high.

The principal object of our invention is to evolve a method of working metal, such as sheet steel, in which the aggregate amount of cold work in the process at large may be as great as desired,

Other objects have to do with the provision of exaggerated grain growth in the metal at any stage of the process, the preservation of the finish of the center'of the disk independently of the working on the outer zones of the disk to reduce the section thereof, and a general economy of energy in the treatment at large. There are yet other objects both of less and equal importance. The only other one We would mention preliminarily is the evolution of a disk produced in the main by cold working and having when complete, all of those qualities most desirable for the makingof wheel bodies by subsequent die drawing. This requires the physical characteristics of the final product to be those of materials, particularly steels, found best for die drawing.

Our process consists primarily in the pre conditioning of the bank at any state of its reduction for substantial cold working by annealing the outer zone only to the exclusion of the inner zone. Stated from another point of view, it may be said to consist in the limitation of the higher ranges of temperature to regions lying wholly without that region within which exaggerated grain growth appears, and the while annealing other portions, in this case the outer zone of the disk, at any temperatures whatsoever which may be found to give most efiicacious annealing. Still further and yet another point, our method consists in protecting those previously diagrammatically an apparatus for carrying,

out this method.

Fig. 1 is a cross sectional view showing.

more or less diagrammatically a preliminary Working of a steel disk by rolling and spinning it from the center outwardly to taper and circumferentially expand the same.

Fig. 2 is an axial cross sectional view showing a furnace with a partially worked disk produced by the operation directed in Fig. 1 in place thereon.

Fig. 8 is a cross sectional detail, the section being taken on the line 33.

Fig. 4 is a view similar to Fig. 1 showing the further working operation to which the disk is subjected after annealing, as by rolling and spinning it from the center outwardly to further reduce its section and expand its periphery.

10 is the wheel disk. It is shown in Fig. 2 as already partly tapered, as by a cold rolling and spinning operation shown in Fig. 1. The tapering process leaves a central zone a (Fig. 2) unworked, i.e., of its original thickness, one adjacent zone I) but slightly worked and one outer zone 0, more originally worked. Only the center remains unreduced and of its original thickness. The metal as a result of this first step of cold working of our invention is unduly hard.

lVe place the disk blank 10 upon the top of a central column 11 of the furnace 12. The diameter of the central column at the top is approximately equal to the diameter of the combined central unworked and hence unreduced zone a and the adjacent slightly worked zone 7) of the disk blank. The furnace 12 is provided with outer walls radially spaced from and concentric with the colthan the external diameter of the disk 10. Heat is applied by injecting flame through suitable burners through a tangentially projected aperture or apertures 13, and swirls around column 11 in rotary contact with the under surface of the outer zone of disk blank 10 and from the open top of the furnace through the space between the outer edge of the disk and the wall 12. The opened top of the furnace in the embodiment shown is substantially flush with the under face of the disk 10. It may be otherwise in accordance with the height of the outer wall 12. The bottom of the furnace is closed.

The heat of the furnace and hence of the outer zones of the disk is regulated to those temperatures which will produce the desired annealing of the outer zone of the disk, whatever these may be.

The massive central column 11 not only protects the center of the disk from contact with the flame, but also assists by its mass in keeping it relatively cool through conduction. ater cooling through the central mass is resorted to if desired. The relative adjustment of column 11 in area, and mass and the adjustment of operating temperatures is such that the zone I) does not reach the minimum temperature at which exaggerated grain growth appears. Nor is the surface of the central portion marred in any way by the flame or heat.

The disk 10 having its outer zone so heated to proper annealing temperature is then removed, and the annealing step completed by proper cooling in any well known way.

Thereupon, cold work upon the disc blank 10 may be resumed in the outer zones 6 and 0 with impunity, as indicated by the additional rolling and spinning action depicted in Fig. 4. After such rolling the metal may be die stamped to the desired form.

Certain classes of steel may be treated by our method before any reduction of section is made with resultant advantage. In the main, however, the first step is an initial reduction of section in the outer zone I) and c, the second, an annealing of the outer zone while the inner zones a and particularly 6, are protected against heat which might produce exaggerated grain growth, and the completion of the product by completing the cold working of the outer zone I) and 0 to reduce the disk to final section as shown in Fig. 4, but obviously the work may be carried out in any number of stages by repetition of ap plication of the method which we have devised. By regulating this application with respect to the amount of cold work done at each stage, the material of the disk blank may be kept in the very best condition for the work to be performed upon it and the resulting finished product will be in the best possible condition for the die drawing whichis to give it contours to constitute it a finished wheel body.

Not the least of the advantages of our invention it will be seen is great economy of energy. This takes place first in an economy of heat utilized for annealing in that by keeping the temperature of the central zones down below the minimum at which exaggerated grain growth appears, the annealing of the outer zones is accomplished at the lowest practicable temperatures. The apparatus of our invention is capable of turning out the completely annealed disk each of one half or three quarters of a minute and the disk blank worked according to our method can be worked with less expenditure of energy because always in the best condition for working.

All of these modifications of our invention which fall within its generic spirit are to be comprehended in the annexed claims.

\Vhat we claim as new and useful and deside to protect by Letters Patent is:

1. The method of forming a tapered disk which comprises annealing the outer peripheral portions of a disk blank while retaining the inner peripheral portions below the temperature at which exaggerated grain growth appears and thereafter cold rolling the outer peripheral portions of the blank.

2. The method of forming a tapered disk which comprises cold rolling a disk blank to an intermediate state, thereafter annealing the outer peripheral portions of the blank while retaining the inner peripheral portions 3810W the temperature at which exaggerated grain growth appears and thereafter cold rolling the outer peripheral portions of the blank.

3. The method of metal working which comprises selectively annealing the portion of a blank which has been subjected to a maximum amount of cold rolling while shielding another portion of the blank to prevent excessive grain growth, and thereafter cold rolling said blank.

4. The method of metal working which comprises cold working a portion while leaving another portion of the work object unworked, in heating the worked portion while shielding the unworked portion from heat, and in annealing the again cold working the portion which has been worked, heated and annealed.

In testimony whereof we hereunto allix our signatures.

GEORGE L. KELLEY. EDWARD G. BUDD.

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