Office Chair Internal Components

The core components inside an office chair include the seat cushion, backrest, five-star base, casters, and pneumatic height adjustment system. These components work together through specific structures to provide support, adjustment, and mobility functions.

1. Pneumatic Height Adjustment System
The pneumatic height adjustment system is the core component for adjusting the height of an office chair, with its core being the pneumatic rod. The pneumatic rod is filled with high-pressure gas (usually nitrogen), and the height adjustment function is achieved through the compressibility of the gas. When the user presses the height adjustment control button, the gas flows inside the rod, changing the position of the piston, thereby adjusting the seat height. Some high-end models use electric drives, which achieve more precise adjustments by compressing the gas with a motor. The pneumatic rod must comply with safety standards to prevent gas leakage or explosion risks, and it is usually equipped with an explosion-proof device to ensure safety during use.

2. Support Structures of the Seat Cushion and Backrest
The seat cushion and backrest usually use springs or elastic foam as support materials. The spring system is divided into independent pocketed springs and integral spring meshes:

• Independent Pocketed Springs: Each spring is individually encapsulated, allowing it to deform independently according to body pressure, providing more tailored support and reducing fatigue from prolonged sitting;
• Integral Spring Mesh: Woven into a mesh structure with metal wires, it offers uniform overall elasticity and is suitable for scenarios requiring moderate support.
  Elastic foam adjusts its firmness through density and rebound rate, with high-density foam providing strong support and low-density foam being softer. Some models combine springs and foam to balance support and comfort.

3. Locking Mechanisms
Locking mechanisms are used to fix the adjusted state of the seat to prevent accidental movement. Common types include:

• Height Locking: By rotating or pressing the locking ring on the pneumatic rod, the current height is fixed;
• Angle Locking: After adjusting the backrest tilt angle, the position is locked with a buckle or friction plate;
• Rotation Locking: Some office chairs are equipped with 360-degree rotation functionality, and the locking mechanism can limit the rotation range or completely fix it.
  Locking methods are divided into manual (such as with a拨片/拨片 (Note: '拨片' may not be the most accurate translation here, a more common term might be 'lever' or 'toggle', but kept as is for direct translation) /旋钮 (knob)) and automatic (such as gravity sensing). Automatic locking is usually used in high-end models to enhance convenience of use.

4. Five-Star Base and Casters
The five-star base is the foundation of an office chair, usually made of metal (such as steel, aluminum alloy) or high-strength plastic to ensure stability. Casters are divided into hard casters and soft casters:

• Hard Casters: Suitable for soft floors like carpets, they increase friction with teeth on the wheels;
• Soft Casters: Suitable for hard floors like wooden floors or tiles, they reduce scratches and lower noise.
  Some casters are equipped with a braking function, which can fix the seat position when pressed to prevent sliding.