Liquid sealed cylindrical-type vibration preventing apparatus

A liquid sealed cylinder vibration preventing apparatus, comprising:

• a main shaft metal fitting;
• an intermediate cylinder metal fitting disposed outside said main shaft substantially coaxial therewith and having a pair of windows facing to each other in a diameter direction;
• a rubber elastic body disposed between said main shaft metal fitting and said intermediate cylinder metal fitting to connect said main shaft metal fitting and said intermediate cylinder metal fitting to each other and having a recess opened to each window of the pair of windows;
• a first diaphragm held on a periphery of one of the pair of windows of said intermediate cylinder metal fitting and being disposed in the windows the recesses of said rubber elastic body;
• an orifice forming member mounted on an outer periphery of said rubber elastic body, said orifice forming member forming a main liquid chamber between said orifice forming member and the recesses and a sub liquid chamber between said orifice forming member and said first diaphragm, and forming on an outer peripheral surface a first orifice passage communicating with the main liquid chamber and the sub liquid chamber, and a second orifice passage extending from the main chamber;
• an outer cylindrical metal fitting disposed outside said intermediate cylinder metal fitting substantially coaxial therewith, and having a communicate window communicated with an atmosphere;
• and
• a second diaphragm held by said outer cylinder metal fitting at a periphery of the communicate window and facing the second orifice passage.