PURPOSE: To enable the change of a spring constant without any change of thickness by providing a plurality of cavities in a hollow cylindrical rubber cushion, and changing the number of the cavities or the shape thereof, or inserting a separate elastic body in the cavities.
CONSTITUTION: A cavity 3b is provided in the thick part of a hollow cylindrical rubber cushion 3 for changing the rigidity thereof, and the spring constants k1 and k2 of the rubber cushion 3 is thereby changed in both vertical and horizontal directions. Moreover, a part of the cavity 3b is changed to a blind cavity 3c for changing the spring constant of the aforesaid cushion 3, or a separate elastic body 10 like a coil spring is inserted in the cavity 3b formed in an axial direction, thereby making it possible to obtain a hollow cylindrical rubber cushion having a wide range of variable rigidity. According to the aforesaid construction, various spring constants can be available even with hollow cylindrical rubber cushion having identical outer dimensions. Also, the injection molding die therefor can be made common to a considerable extent, and a hollow cylindrical rubber cushions with various spring constants can be manufactured at less cost.
KOBAYAKAWA TAIICHI
SHIRAFUJI YOSHINORI
TAKIMOTO SUNAO
SUZUKI KENJI
HAGIWARA SHOJI
SUZUKI SATOSHI
