Patent ID: 7125008
Filing Date: 2006-10-24
Classification: F16F

Abstract:
1. A vibration isolation device comprising: a stationary housing; a movable top plate positioned horizontally above said stationary housing; an airtight flexible member for forming an airtight pressure chamber between said movable top plate and said stationary housing; a vibration-free movable base having a mounting plate portion on which an object to be isolated from vibration is mounted, said vibration-free movable base being positioned horizontally to face said movable top plate, and being capable of moving up and down relative to said stationary housing; and a dome-shaped contacting portion, provided between opposed surfaces of said movable top plate and said mounting plate portion, via which planar centers of said movable top plate and said mounting plate portion are capable of coming into point contact with each other, wherein said movable top plate is moved up and down by varying an internal pressure of said airtight pressure chamber, wherein said vibration-free movable base is moved up and down via said dome-shaped contacting portion, and wherein said vibration isolation device includes a biasing device, positioned inside said airtight pressure chamber, for defining a downward movement limit of said movable top plate relative to said stationary housing, and for holding said planar centers of said movable top plate and said mounting plate portion in contact with each other when said internal pressure of said airtight pressure chamber is smaller than a predetermined value.