How it works 

 

The height of a Jack Bench can easily be adjusted up or down to suit what ever task you are working on.

 

Also, the bench can be lifted up on to the built in Mobile Base so that anyone can move it around.

 

It can be operated with a crank handle, or a cordless drill.

 

Fundamentally, there are three things that make this work.

 

Telescoping legs

The legs on the bench base are actually torsion boxes.  Torsion boxes add strength and stability with less weight and lower cost than solid materials.  Each "leg" is comprised of two torsion boxes.  These boxes slide past each other allowing the bench top to raise or lower as needed.

 

Scissors Jack(s)

The bench is raised and lowered by an ordinary scissors jack like the one in the trunk of your car.

 

Also, the bench is lifted up off of the floor by a second scissors jack.  This second jack rests on a cart.  When the jack is raised up it actually picks the bench up off of the floor and on to the cart.  This allows the bench to be wheeled around as needed.

 

Pipe Clamps

What holds this bench in position and makes it so solid is a set of ordinary 3/4" pipe clamps.  These pipe clamps extend all the way through the base and clamp the torsion boxes together.  This locks the telescoping legs into one solid base unit.  To adjust the bench you loosen the clamps by about one turn each, then adjust the scissors jack until the bench is where you want it, then all you do is tighten up the clamps and your're done!