Patent ID: 8523153

Claim:
A spring provided between a first member and a second member, the spring comprising: a main body portion having a hole portion; a first cylindrical portion provided at a radially inner circumference and a second cylindrical portion provided at a radially outer circumference of the main body portion; a first corner portion formed at a boundary portion between the main body portion and the first cylindrical portion; and a second corner portion formed at a boundary portion between the main body portion and the second cylindrical portion; wherein the main body portion is extended in a crossing direction with respect to a direction in which the spring is compressed from the first member and the second member, the first and the second cylindrical portions have an abutting portion protruding from each circumference of the main body portion toward one of the first and the second members and abutting thereat, the first and the second corner portions can be elastically deformed while varying angles thereof according to a suppression strength, the first and the second corner portions define tangent lines along the main body portion, and at least one of the tangent lines has a predetermined angle with respect to a straight line between the radially inner circumference and the radially outer circumference of the main body portion, and a cross-sectional surface of the main body portion contains at least one S-shaped cross section, the cross-sectional surface being bisected in the middle with a concave portion at an upper portion of the cross-sectional surface and a convex portion at a lower portion of the cross-sectional surface.