The biggest problem that needed to be solved was how this stand could be adjustable in height and still maintain support to hold a laptop. It was speculated that the solution could come from frictional links, springs, or a physical support. Ultimately a modified frictional linkage system was chosen for this prototype. The apparatus is originally designed to support a laptop, but it has since been used for a myriad of operations. My favorite is for holding sheet music on a table top.
right hand & left hand threaded shoulder screws x 12
1/4'' hot rolled steel
rubber bumper feet x 4
The Linkage system
A close-up of one of a joint is presented above. These joints aren’t simply rotating members. As the links extend in height the shoulder screw tightens increasing the pressure where the links rotate. This in turn causes the friction to increase making a more rigid system the higher it is extended.