Patent 7140218 was granted and assigned to Toyota on November, 2006 by the United States Patent and Trademark Office.
A rolling apparatus includes a pair of small rolling roller and a large rolling roller which hold a ring with the ring being sandwiched therebetween, and which roll the ring, and a tension roller; a temperature sensor which measures a temperature of the ring before rolling; a storing portion which stores, in advance, a relation between the temperature of the ring and a temperature correction coefficient for correcting a condition for rolling; and a controller which changes the condition for rolling based on the measured temperature of the ring and the stored relation so as to perform rolling processing.