Patent ID: 8333368

Claim:
A hydraulically damped mounting device comprising: first and second anchor parts connected by a first deformable wall; a working chamber partially bounded by the first deformable wall, the working chamber containing hydraulic fluid; a compensation chamber for the hydraulic fluid, the compensation chamber being partially bounded by a second deformable wall; a first passageway interconnecting the working and compensation chambers to allow movement of the hydraulic fluid between the working and compensation chambers; an auxiliary chamber for hydraulic fluid, the auxiliary chamber being partially bounded by a third deformable wall; a second passageway interconnecting the working chamber and the auxiliary chamber; a vacuum chamber connectable to a vacuum source for varying the pressure in the vacuum chamber, the vacuum chamber being partially bounded by an abutment part movably mounted therein, the abutment part being movable in response to a change in pressure in the vacuum chamber between a first position in which the abutment part bears against the third deformable wall such that the third deformable wall is deformed to close the second passageway and a second position in which the abutment part allows the third deformable wall to adopt a position in which the second passageway is open; and a resilient biasing member arranged to bias the abutment part towards the first position, wherein the abutment part is connected to a wall of the vacuum chamber by a rolling diaphragm to permit movement of the abutment part relative to the wall of the vacuum chamber.