[math-fun] line segment passing through a hyperbola-shaped slit

Is there a video on the web of a line segment passing through a hyperbola-shaped slit, as in the Eames Mathematica exhibit (and probably other math museum exhibits as well)? I want to show this to my calculus students tomorrow, and was astonished that I couldn't find it on the web even after several minutes of searching ("... Eames ruled surface hyperbola ...". Thanks, Jim Propp