Ever wondered how that desk chair you love so much pops up in height so easily when you push the height adjustment lever? Or, why it doesn't pop up but slowly drags its way up? Compressed air is the mechanism that makes the chair work. Compressed air (gas) is the way all pneumatics work, even power tools, like nail guns and staple guns. Compressed gases (air is a gas) are used to assist mechanical motion or processes. Air in the atmosphere is sometimes captured for this purpose especially in industrial (factory) applications. Pneumatic chairs, on the other hand, use compressed air to move the seat up and down.
Pneumatic Chair Components
The base of the chair, usually a three, four or five star metal base, is used to insert a gas cylinder into. The gas cylinder, also called a gas lift or spring, is then shrouded with a telescoping cover to create a column. Placed on top of this column is the seat. The underside of the seat has a metal plate that is used to attach the pneumatic column and base to the seat. The seat plate contains the levers used to operate the pneumatics. The levers push a piston into the cylinder allowing the column to lift the chair up and down. The telescoping shroud is meant to protect the cylinder. Each manufacturer sells slight variations of pneumatic columns including different locations for the levers or a more revealing look at the cylinder by not concealing the lift with a telescoping cover.
Using A Pneumatic Chair
The pneumatic chair uses a single acting cylinder or gas (air) spring filled with air. The air chamber is connected to a plunger or piston that when activated with the lever mechanism, moves into or out of the chamber. The air is pushed by the plunger and further compressed. The pushing of the contained air forces it together (compression) and causes a springing, or lifting, movement. Releasing the piston expands the air. The volume of air contained in the cylinder can be adjusted to make the spring more or less forceful in its movement. The spring is merely making the motion of lifting the seat happen more easily. Without the spring the user would be required to move the seat up and down manually and probably use a knob or pin to stabilise the height.
Replacing The Pneumatic Spring
Pneumatic springs will wear out over time. The cylinders can be replaced. Follow manufacturer's directions for replacement or take the chair to an authorised dealer for assistance. Standard cylinders can be purchased easily but removing them can be difficult depending upon how they were attached by the manufacturer.