Reply by MrRon

“you would have to walk around and tighten all those knobs upon raising and then lowering.”

My design uses only 2 locking knobs, located on one end only along with the drive for the jacks. The casters retract automatically upon raising the bench, so the bench rests on solid flooring.

“It’s a clever design, but what’s the purpose?”

The purpose of the bench is to allow it to be raised/lowered to suit individual’s working height preference, especially applicable to people with bad backs.