Vibration isolator with electrorheological fluid controlled dynamic stiffness

DETAILED DESCRIPTION What is claimed is: 1.
Apparatus for connecting between two members for supporting said members and isolating them from input excitations, said apparatus comprising a housing formed in part of resilient material and defining a first fluid chamber containing a hydraulic fluid, means responsive to said input excitations for varying the volume of said first chamber to isolate said members from said input excitations, a first electrode disposed in said first chamber, a second electrode disposed in said first chamber and defining, with said first electrode, an enclosed second chamber, said second electrode being responsive to variations in the volume of said first chamber for moving relative to said first electrode for varying the volume of said second chamber, an electrorheological fluid enclosed in said second chamber and isolated from said hydraulic fluid of said first chamber, and means responsive to said input excitations for varying the yield stress of said electrorheological fluid to control said movement of said second electrode and therefore the variations of said volume of said first chamber to control the dynamic stiffness characteristics of said isolator.
2.
The apparatus according to claim 1 wherein said means responsive to said input excitations comprises a first element connected to one of said members and a second element connected to the other of said members, wherein one of said elements is operatively connected to said resilient material.
3.
The apparatus according to claim 1 wherein said means for varying said yield stress includes electric field generating means for providing a voltage potential between said electrodes.
4.
The apparatus according to claim 3 wherein said electric field generating means comprises a power source and wiring extending between said power source and said electrodes.
5.
The apparatus according to claim 3 further comprising computing means responsive to said input excitations for varying the voltage potential applied between said electrodes