The pantograph was also proposed at least as far back as 1994 as a useful kinematic system for haptic computer interaction, see this movie http://www.cim.mcgill

The pantograph was also proposed at least as far back as 1994 as a useful kinematic system for haptic computer interaction, see this movie http://www.cim.mcgill.ca/~haptic/devices/pictures/pantograph.mpg http://www.cim.mcgill.ca/~haptic/devices/pictures/pantograph...