US Patent 7159856 Fluid sealed antivibration device

A partition member for dividing a fluid chamber into a main fluid chamber and a sub-fluid chamber is provided with an idle orifice passage of which the opening is opened and closed by a seating section provided on part of a diaphragm. A pushing member is provided to control the opening and closing operation. The seating member is formed thick of which the upper and lower surfaces are provided with depressions respectively. The seating member is also provided with a thin section of which the periphery is provided with a hemispheric protrusion and a seal of a substantially right triangle cross section. An elastic body section is also provided at the side surface with a lateral membrane section.