A method is provided for supporting a load such as a computer terminal by balancing the load with two opposed parallel forces of different magnitudes which are algebraically added with the weight of the load to result in a gravitationally neutral or statically stable (or dynamically stable) condition...http://www.google.com/patents/US4768744?utm_source=gb-gplus-sharePatent US4768744 - Apparatus for supporting a load in a dynamically balanced condition
