PURPOSE: To enable the functions of vibration-proof and sound cutting-off to be effectively displayed underwater by providing a flexible air bag enclosing the air pressure of a predetermined pressure on the back surface side of a surface plate at a space between the surface plate constituting a vibration-proof mechanism and a base.
CONSTITUTION: A flexible air bag 10 enclosing a predetermined air pressure is fitted at a space between a base 1 and a surface plate 5, and is on the back surface side of the surface plate 5. This air bag 10 is made up of air having a low spring constant, and a rubber-like material, and also, is furnished in one body to the back surface side of the surface plate 5. And, springs 3a, 3b and the surface plate 5 do not require water pressure-proof structure, and a characteristic is that the air bag 10 is compressed and decreases in its volume when used especially under a high water pressure, and the surface plate 5 and the air bag 10 are closely stuck in case of the remaining quantity of air becoming extremely small, and the functions of vibration-proof and sound cutting-off are lost, but breaking does not occur, and the functions of vibration-proof and sound cutting-off are restored when pressure is again recovered.
NAKAMURA KAORU
KAMEI AKIHIRO
YOKOHAMA RUBBER CO LTD