US Patent 8720838 Articulating monitor arm with chain and spring

The present application teaches an extension arm including an articulating portion that approximately counterbalances the mass of the articulating portion and any objects connected thereto, for example an electronic device, throughout the positional range of the articulating portion, via the operation of a counter-balancing mechanism. In some embodiments according to the disclosed inventive concepts, the counter-balancing mechanism employs a spring coupled to a chain at a first end, the chain being connected at its opposite end to a pivoting member with which it interacts to support the articulating portion of the extension arm and any objects connected thereto.