Patent ID: 9545932
Date: 2017-01-17
CPC Classifications: B21D,B61D,C21D

Claim:
1. A method of manufacturing a railroad car tank head comprising the steps of: providing a circular blank of steel plate material; cold-forming the circular blank to form an intermediate ellipsoidal dish, wherein a temperature of the blank is not greater than 200° F. during the cold-forming; cold-forming a peripheral flange region of the intermediate ellipsoidal dish to form a flanged ellipsoidal dish, wherein a temperature of the intermediate ellipsoidal dish is not greater than 200° F. during the cold-forming of the flange region; and heat treating the flanged ellipsoidal dish; wherein the step of providing a circular blank of steel plate material includes providing a plurality of circular blanks of steel plate material, and the step of cold-forming the circular blank includes simultaneously cold forming the plurality of circular blanks to form a plurality of curved dishes, wherein a temperature of each blank is not greater than 200° F. during the cold-forming.