This assembly of spherical rhombus linkages expands to enclose a volume. It was designed by Jerome Choe to explore the construction of complex articulated systems. (UCI Robotics and Automation Lab)
Animations of linkage movement.
Fred Klingener has generated a number of interesting mechanism animations. My favorite is the Peaucellier straight line mechanism. You will find a table of 16 or so animations at his site:
This link connects to a web-page with a number of linkage animations. There are several planar four-bar linkages, several spherical four-bar linkages, and an example of a spatial four-bar linkage called a Bennett linkage that is shown below. This page also includes a number of spherical linkage animations generated by students some years ago. (UCI Robotics and Automation Lab)
This animation was generated by HaiJun Su using POV-Ray. It is a Bennett linkage designed to guide the coupler linkage through three specified task positions:
This spherical eight-bar linkage was designed by GimSong Soh to guide a car door from the side to the top of the vehicle. This animation shows the versatility of movement provided by these linkages. (UCI Robotics and Automation Lab)