Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators

Generally, adjustment of gravity equilibrators to a new payload requires energy, e.g., to increase the preload of the balancing spring. A novel way of energy-free adjustment of gravity equilibrators is possible by introducing the concept of a storage spring. The storage spring supplies or stores the energy necessary to adjust the balancer spring of the gravity equilibrator. In essence, the storage spring mechanism maintains a constant potential energy within the spring mechanism; energy is exchanged between the storage and the balancer spring when needed. Various conceptual designs using both zero-free-length springs and regular extension springs are proposed. Two models were manufactured demonstrating the practical embodiments and functionality. [DOI: 10.1115/1.4004101]