Configuration Synthesis of Mechanisms with Variable Topologies: the Study on Configuration Synthesis of Sawing and Lock Mechanisms

Mechanisms with multiple topological structures during the operation process are called mechanisms with variable topologies (MVTs), and their corresponding kinematic chains are called variable chains. The kinematic joints whose types and/or motion orientations are changeable during the operation process of an MVT are called variable joints. This work presents a systematic design methodology for MVTs. First, locutions of mechanisms with multiple configurations are introduced. Then, the topological characteristics of variable joints subject to input motions are investigated. A mapping function method is provided to describe the topological characteristics and to determine the relationships of configurations. Moreover, fundamental synthesizing corollaries are established. A sawing mechanism and a mechanical lock are exemplified to analyze their configuration transformations. Finally, a design methodology is proposed for the configuration synthesis of MVTs. A sawing mechanism and mechanical locks are exemplified to verify the feasibility of the design methodology. And, twenty-three new sawing mechanisms, and five new mechanical locks with variable passwords are obtained.