A rubber vibration insulator comprising a boss member as one fitting, a tubular body, an annular elastic member interposed between the boss member and one end of the tubular body, a plate member as the other fitting surrounding fixedly the opposite end of the tubular body, thus forming together with the aforesaid elements a sealed chamber having variable volume, and a capsule housed in the sealed
... [Show full abstract] chamber, in which a damping liquid is filled. The capsule comprises an external shell consisting of a rubber plate having an orifice and a plate body joined together and a diaphragm disposed transversely in the shell, thereby dividing its internal chamber into an air sub-chamber on the rubber plate side and a liquid sub-chamber on the plate body side. The rubber plate of the shell may be defined with recesses on both sides in a vertical symmetry and dispersedly to form thin film portions or be in the form of a thin rubber plate which is interposed between two porous plates at a clearance and play between them. With the arrangement of the capsule, the spring rate of the diaphragm can be lessened and the liquid pressure in the sealed chamber can be prevented from rising in the high frequency region. Thus, muffled sounds and transmission sounds are insulated.
