Office Chair Telescopic Rod

The office chair telescopic rod is a rectangular metal tube hidden inside the chair that controls the chair's height. It is generally operated via a handle or button and mainly consists of two parts: a hydraulic rod and a pneumatic rod.

Working Principles

• Hydraulic Principle: The hydraulic system in the office chair telescopic rod is based on the principle of force generation through the transmission of pressure by liquid in a closed pipeline. It contains oil and gas internally, forming a closed hydraulic system with a cylinder body, oil cylinder, and piston. When the user pulls the handle or presses the button, the bottom piston moves upward, compressing the oil in the oil cylinder and generating pressure in the oil. This pressure pushes the upper piston upward, thereby raising the chair. For example, in office scenarios that require precise height adjustment, the hydraulic principle provides a stable and controllable lifting process.
• Pneumatic Principle: The pneumatic rod plays a crucial role in bearing the weight of the chair and maintaining balance in the office chair telescopic rod. It works in conjunction with the hydraulic rod. When someone sits on the chair, the pneumatic rod experiences pressure and generates a reaction force. This reaction force enables the chair to remain steadily at the height desired by the user. For instance, when people of different weights sit on the chair, the pneumatic rod can automatically adjust according to the changes in pressure to ensure the chair's stability.

Key Components and Adjustment Process

The gas lift cylinder is a key component for the height adjustment of the office chair. One end of it is connected to the bottom of the seat, and the piston end is fixed to the top of the outer shell. There is a small push valve at the top controlled by the height adjustment lever. In the initial state, when the piston is outside the cylinder, the atmospheric pressure inside and outside the cylinder is equal. When the user pushes the piston upward, it compresses the air inside the cylinder, making the pressure inside the cylinder higher than the external atmospheric pressure, thus creating a pressure difference and a net force. To support the user's weight, the cylinder is filled with compressed gas. During height adjustment, some gas can be released through the control valve to reduce the pressure inside the cylinder, allowing the piston to move upward and raise the chair. If the piston reaches the top, gas needs to be redirected back from an external cylinder filled with compressed gas to complete the next height adjustment.