A bi-stable revolute hinge for Variable Geometry Structures

A Rolamite hinge is made up of two rollers held by three tensioned bands attached to either part, with ends of each band terminating on opposite sides of the hinge, ensuring a no-slip condition. This paper investigates the existence of alternative forms of the Rolamite hinge by changing the profile of the rollers or tension band surfaces. The aim is to achieve a novel bi-stable revolute hinge that can be built into Variable Geometry Structures (VGSs). This hinge consists of two prismatic blocks connected through three fiber wires wrapped around them, that prevent any motion between blocks unless relative rotation along their axis. A set of design parameters is used for introducing the concept of bi-stability. The relationships concerned in either design or mechanical behavior are established in providing a proper use of the hinge. However, these relationships represent only a preliminary analysis of a deeper one that it should be carried out to build a physical model.