US1728641A - Car wheel - Google Patents

Description

Sept. 17, 1929.

J. J. TRANT ET AL I CAR WHEEL Filed Dec. 6, 1928 Patented Sept. 17, 1929 UNITED" STATES PATENT OFFICE JAMES J. TRAN! AND MARTIN JENSEN, OF CHICAGO, ILLn'voIs, AssreNons'ro rum.-

MAN can &M.A1\TUFAGTURING CORPORATION,

TION OF ILLINOIS or CHICAGO, ILLINOIS, A oonronn- GAR WHEEL Application filed December 6,1928. Serial No. 324,214.

The invention relates to cast metal car wheels and has for its principal object the production of awheel of the single plate type having a chilled tread surface.

5 An important object is to form a cast metal wheel having a single plate andan annular cored out portion in the hub area. I

Another ob'ect is to reduce the amount of metal required in the manufacture of a wheel of a given capacity and to expedite the production thereof. I I g A further object is to so distribute the metal in the wheel that shrinkage stresses and re:-. sultant Wheel failure will be reduced to a minimum, or avoided. I

The foregoing and other objects are attained by the construction illustrated in the accompanying drawings, in which:

Fig. l'shows thedouble plate chilled cast iron wheel heretofore generally used;

Fig. 2 shows the chilled cast iron wheel of the single plate type recently adopted as standard by the American Railway Association;

Fig. 3 shows a similar wheel modified in accordance with the invention;

Fig. 4.- shows the modified wheel with a por tion of the hub broken away to expose the annular cored out portion thereof in accordance with the invention; and Fig. 5 indicates the manner of supporting the annular core in the hub of the wheel during the process of manufacture.

In the manufacture of the single plate wheel of the type now regarded as standard practice, some diliiculty has been found in the production of wheels free from shrinkage cracks. This condition has been due in large measure to the presence of the relatively great 4 mass of metal in the hub area with respect to the thickness of the surrounding plate of the wheel. During the casting process, it was found that the plate portion solidified in the mold morerapidly than did thehub having relatively greater thickness of metal, with the result that the solidification of the hub metal inthe mold was retarded by the relatively plastic condition of the metal beneath the hardening surface of the hub and delayed the removal of the casting :to the soaking pit, Heat radiation from the'sand mold being relatively morerapid than'that from the core metal in the hub mass," that portion of the mold defining the Wheel plate area would cool more rapidly than elsewhere and cause thecoolingplate metal to shrink and draw metal from the relatively hot mass at thehub as the plate metal solidified.

To overcome the condition inherent in wheels of. the type indicated,,it is purposed to reduce the mass of metal at the junction of plate and hub as best shown in Figs; 3, 4, and 5, of the drawings, in which lOi'epresents an annular core traversing the wheel at the junction of plate .11 and hub 12 and dis- I placing the metal formerly occupying that space. Except for the presenceof thecore holes 13,-the contour of the inner face of the 7 present standard single plate Wheel has been wheel. Obviously, the lack of metal in' the, core space 10 facilitates the moldingof the wheel by the more equable distribution of the metal in the hub withrespect to the volume of metal in plate 11, since it permits the uniform cooling andthereby the flow of metal in the plate area at the hub toavoid the stressing of the metal at that point. Thus disposed, the hub metal solidifies rapidly enough to permit the relatively early transfer ofth'e wheel from I the mold to the soaking pit before; theplate 11 ofgthe wheel has had time to cool in the sand, thereby preventingv any undue stressing ordrawing down of the metal inth'e bore oft-he hub,- and the fasterthewheels solidify in the mold the ,sooner theycanbe removed to the soaking pit after pouring. a

Since the time interval betweeii the pouring of the metal and the transfer of the wheel to the soaking pit must be kept at aminimum in the manufacture of the wheel, the speed with which the hub and adjoining plate metal solidifies and adjusts itself within the critical heat range of the iron before the wheel is removed to the pit becomes important in the production of wheels having the proper physical characteristics.

,Thus constituted the plate 11 of the Wheel may be made thick enough to dispense with the reinforcing ribs 9 disposed radially across the plate of the two-plate wheel formerly used as indicated in Fig. 1. Such ribs formed objectionable T-sections with plate, resulting in the unequal cooling of the casting in the mould and the consequent stressing or initial fracture of the relatively thin metal of the ribs 9 which cooled faster than the greater mass of metal at their bases where they oined the plate. In the present embodiment, because of the absence of core metal in the hub area, the heat generated by the pressing of the wheel upon the axle is rapidly'dissipated, preventing the scoring of wheel bore and axle incident to that operation. Ihe annular core space 10 of the wheel is formed by preparing the mold '19 shown in Fig. 5 with an annular sand core 20 supported bychaplets 21 and held from displacement by core prints 22. The inpouring metal 23 flows about the core and prints to provide the core holes 13 and space 10 best indicated in Figs. 3 and 4:.

It will be evident from the foregoing description that'the wheel indicated in Figs. 3 and 4c is of greater strength because of the more equable distribution of metal and resul ant elimination of hub shrinkage strains, and actual tests have indicated a substantial increase in the strength of the wheel as compared with that of the single plate solid hub wheel'oflike capacity. That becauseof the i more rapid solidification of the wheel in the mold an earlier transfer to the soaking pit is possible while the wheel is yet within the critical heat stage, thereby insuring a more effective annealing of wheels free from initial stresses and incipient hub shrinkage cracks or draws, and other defects. Thru the compensating action of the chiller ring the solidification of .the rim mass of the Wheel metal is effected as quickly as that of the metal in the car wheel of the standard A. R-A. type for wrought steel wheels having a single plate portion and a cored hub section, said plate having bifurcated web portions uniting said plate and hub.

3. A car wheel of the standard A. R. A. type for wrought steel wheels having a cast single plate portion and a cored hub.

4. A car wheel of the standard A. It. A type for wrought steel wheels having a cast single plate portion and a hub having an annular cored out portion, and spaced web portions connecting said hub and plate.

5. A cast metal car wheel of the standard A. R. A. type for wrought steel wheels having a dished single plate portion and a hub, and an annular .cored out portion intermediate said hub and plate.

6. A cast metal car wheel of the standard A. It. A. type for wrought steel wheels having a straight single plate portion dished inward- 1y from the tread and ahub, and an annular cored out portion intermediate said hub and late. p 7. In a cast metal wheel of the standard A.

R. A. type for wrought steel wheels, the combination comprising a single plate portion and a cored hub, and a plurality of diverging web portions defining an annular core about said hub and uniting said hub and plate.

8. In a cast metal car wheel of the standard A. R. A. type for wrought steel wheels, the combination comprising a single plate portion dished inwardly from the tread and including the hub, and a plurality of diverging web portions defining an annular core about said hub.

In witness whereof we have hereunto set our hands this 22nd day of November, 1928.

. JAMES J. TRANT.

MARTIN JENSEN.

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