Date of download: 10/15/2017 Copyright © ASME. All rights reserved. From: Spring-to-Spring Balancing as Energy-Free Adjustment Method in Gravity Equilibrators J. Mech. Des. 2011;133(6):061010-061010-10. doi:10.1115/1.4004101 Figure Legend: The rolling link spring-to-spring balancer (a) consists of a bar rolling on a support disk, with two fixed pulleys on either end. The wires connected to the springs run over the fixed disks at the end of the rolling bar. As shown in (b) the system works by creating two isosceles triangles having one side with length L/2 lying back to back. In order for the wires to be parallel to the isosceles triangles (c) the radius of the rolling links rr must be equal to rp2 . In (d) the wrap angles of the wire are determined, and it is shown that Σβi=π/2, independent of ϕ. Therefore, the balancing is exact.