Mobile assemblies based on the Bennett linkage

Abstract

This paper presents a method of building large mobile assemblies using the Bennett linkage. The method is based on a basic single-layer layout consisting of overlapping 4 R loops, each of which is a Bennett linkage. The assemblies created have a single degree of freedom, and are overconstrained and scaleable, allowing unlimited extension by repetition. In general, they deploy into a circular or non-circular cylindrical profile. The joints of the assemblies move spirally on the surface during deployment. Under some particular geometrical conditions, the profiles of the assemblies can become arch-like or flat. Moreover, the single-layer assemblies can be extended to form multi-layer mechanisms, even mobile masts. The paper shows the great versatility of the Bennett linkage and demonstrates that the century-old invention can play an important role in the construction of deployable structures.