PURPOSE: To obtain a uniform product easily by imparting an initial compression strain to the rubber cylinder through a forced diameter-wise compression of the entire outer cylinder device after a inner cylinder of large-diameter device is force pressed into a rubber cylinder integrally with the outer cylinder device with a tapered guide at the central part of the circumference.
CONSTITUTION: A rubber cylinder 1 is press molded on the inner surface of an outer cylinder device 2 in such a manner that it is bonded by vulcanization with the inner surface thereof in an axially central circle. Then, an inner cylinder device having the outer diameter larger than the inner of the rubber cylinder 1 is inserted into a core 8 fixed on a press 7 and locked with a tapered guide 9. The press 7 is moved toward the rubber cylinder until the inner cylinder device 3 is force pressed into the rubber cylinder 1. The guide 9 is removed and the outer cylinder, the rubber cylinder and the inner cylinder are integrated. The outer cylinder device 2 thus integrated is forcedly reduced in the diameter by passing thereof through a outer cylinder drawing dies 12 using presses 13 and 10. The forced pressing and diameter reduction lead to obtain a sufficient compression strain.
UEDA SUTEO
KADOWAKI HIDEO
