Patent ID: 7491284

Claim:
A method for forming a rubber member by overlapping and winding at least one rubber strip in a circumferential direction and in a spiral shape, wherein a cross sectional shape of said rubber strip is a scalene triangular shape defined by a bottom line, a first diagonal line extending from one end of the bottom line to a facing apex and a second diagonal line extending between the other end of said bottom line and said facing apex and being shorter than said first diagonal line, a length L 0 of said bottom line in the rubber strip is equal to or more than 5 mm and equal to or less than 50 mm, and a thickness T thereof is equal to or more than 0.2 mm and equal to or less than 5.0 mm, and a length L 1 of said first diagonal line along said bottom line is set larger than 0.5 times and equal to or less than 0.8 times the length L 0 of said bottom line, wherein said at least one rubber strip is two rubber strips which are a first rubber strip and a second rubber strip having the same cross sectional shape, the first rubber strip is wound from a wind start position close to one end of the rubber member to a wind end position close to the other end of the rubber member, the second rubber strip is wound from a wind start position close to the other end of the rubber member to a wind end position close to the one end of the rubber member, passing each other with respect to said first rubber strip, and in the wind start positions of the first and second rubber strips, said one end of the bottom line of each of the first and second rubber strips is directed to an axially outer side of the rubber member.