Office Chair Spring
The common types of springs in office chairs are tray springs and gas springs (pneumatic rods), with significant differences in their functions and structures.
Tray springs are the core components for the reclining adjustment function of office chairs, typically installed in the tray structure connecting the backrest and the seat. Their working principle is based on elastic deformation: when a user leans back, the spring is compressed, generating deformation and storing elastic potential energy; when released, the spring returns to its original shape and releases energy, pushing the backrest back into place. This design controls the reclining force through the spring's elastic coefficient, ensuring that users of different weights can obtain a comfortable sense of support. Tray springs are mostly made of high-carbon steel or alloy steel, requiring high fatigue strength and creep resistance to withstand long-term and frequent deformation cycles. Their structure is usually helical, and the elastic limit is enhanced through heat treatment processes to avoid permanent deformation or fracture risks after long-term use.
Gas springs (pneumatic rods), on the other hand, are the key devices for achieving the height adjustment function of office chairs, with their core principle based on the pressure differential drive of high-pressure nitrogen. The interior of a gas spring consists of two gas chambers, initially separated by a sealing valve. When height adjustment is needed, the control valve is triggered to connect the two chambers, allowing high-pressure nitrogen to flow from the high-pressure chamber to the low-pressure chamber, pushing the piston rod to extend or retract, thereby achieving smooth lifting and lowering of the seat. This process requires no external power and is completed solely through the pressure differential, featuring rapid response and effortless operation. The performance testing of gas springs covers multiple indicators: appearance dimensions must comply with design tolerances to ensure matching with the chair structure; force characteristics testing includes parameters such as lifting resistance and rebound force, directly affecting the user experience; sealing testing is conducted by observing pressure retention after high-pressure inflation to prevent nitrogen leakage and functional failure; durability cycling simulates long-term use scenarios to verify the performance stability of the piston rod after a certain number of extensions and retractions (usually over 50,000 times); safety performance involves explosion-proof design, such as built-in safety valves that can automatically relieve pressure in case of abnormal gas pressure to avoid explosion risks.
The two types of springs have clear divisions of labor in office chairs: tray springs focus on reclining support, while gas springs dominate height adjustment, jointly forming the core functional modules of ergonomic chairs.
