Hydraulic chairs, more accurately described as pneumatic chairs, work using compressed gas within a cylinder to control the chair's height. Here's a breakdown of the process:
1. The Pneumatic Cylinder:
- This is the core component. It's a sealed cylinder containing compressed gas, typically nitrogen.
- Inside the cylinder is a piston, which can move up and down.
2. Pressure and Movement:
- The compressed gas exerts pressure on the piston.
- A valve controls the release of this pressure.
3. Height Adjustment:
- When you pull the lever on the chair, it opens the valve.
- Opening the valve allows some of the compressed gas to either enter or exit a chamber within the cylinder, affecting the pressure on the piston.
- This change in pressure causes the piston to move, either raising or lowering the chair.
4. Lowering the Chair:
- When the valve is opened to lower the chair, some gas is typically allowed to move to a different chamber, reducing the supporting pressure under the seat.
- Your weight then pushes the piston down, lowering the chair.
5. Raising the Chair:
- When the valve is opened to raise the chair, gas might be allowed to flow, increasing pressure.
- The increased pressure pushes the piston up, raising the chair. Your weight is then supported by this increased pressure.
6. Locking the Height:
- When you release the lever, the valve closes.
- This seals the cylinder, trapping the gas at a specific pressure.
- The piston is then held in place, maintaining the chair's height.
Analogy:
Think of it like a bicycle pump. The cylinder is the pump body, the piston is what you push, and the valve controls the air flow. In a chair, the gas is already compressed, and the valve simply regulates its movement to control the chair's height.
In summary, pneumatic chairs utilize compressed gas within a cylinder and a valve mechanism to efficiently adjust and maintain the desired seat height.
