Earthquake-protective support system for electrical apparatus

Claim 1

A support system for electrical apparatus having a tall, slender profile that is capable of protecting the apparatus against severe earthquake forces, comprising: a. a rigid substantially horizontally-extending platform on which said apparatus is mounted, b. a rigid framework supported on and rigidly anchored in the ground, said framework having portions located above and spaced from said platform, c. means for suspending said platform from said framework portions comprising: at least three spaced-apart substantially rigid pendulum links and universal joints at opposite ends of said links for respectively connecting the associated link to said framework and said platform, said links being of substantially the same length, of a constant effective length, and substantially parallel to each other so as to form a parallelogram type linkage that maintains said platform substantially horizontal when moved relative to said framework, d. releasable restraining means for normally maintaining said platform fixed with respect to said framework but releasable to permit movement of the platform relative to the framework in response to horizontally-directed acceleration exceeding a predetermined minimum value of the ground in which said framework is anchored, e. damping means opposing motion of said platform relative to said framework for dissipating the kinetic energy of the platform and the apparatus mounted thereon developed by motion of said platform relative to said framework.