Patent ID: 7341243

Claim:
A hydraulic style vibration-proof device comprising: a cylindrical fitting; a first attachment fitting; a vibration-isolating base made of rubber elastomer coupling an upper end opening of the cylindrical fitting and the first attachment fitting; a diaphragm disposed to oppose the vibration-isolating base and forming a liquid chamber between the vibration-isolating base and the diaphragm within the cylindrical fitting; and a cup-shaped second attachment fitting disposed below said diaphragm and attached to a lower end opening of the cylindrical fitting, forming an air chamber between the second attachment fitting and the diaphragm, wherein said second attachment fitting is fabricated from aluminum and includes a peripheral wall portion, a bottom wall portion formed to be thicker in wall thickness than the peripheral wall portion and a curved portion interposed between the bottom wall portion and the peripheral wall portion and curved in an arc form in axial cross-section; wherein the bottom wall portion is defined with a through-hole and has a bolt having a serration portion below its head press-fitted in the through-hole and provided fixedly to the second attachment fitting in such a manner that the bolt juts out from the second attachment fitting downwardly, wherein a thickness of the second attachment fitting is gradually increased from the bottom wall portion toward the curved portion until reaching a maximum at the curved portion and then gradually decreased to the peripheral wall portio, and wherein a plane of the upper end opening of the second attachment fitting slants relative to the bottom wall portion in a manner such that the peripheral wall portion is formed at different heights in the circumferential direction and at a higher location of the peripheral wall portion, a thickness at a corresponding location of the curved portion is thicker.