Office Chair Base Plate

The office chair base plate, also known as the chassis, is a crucial component that connects the seat cushion, backrest, and gas lift, providing functions such as fixed connection, reclining, and adjustment.

I. Main Functions of the Chassis As the core structural part of an office chair, the chassis serves three primary functions:

1. Fixing and Connecting: It integrates components such as the seat cushion, backrest, and gas lift into a whole using metal plates or plastic casings, ensuring the stability of the chair's structure.
2. Reclining: It incorporates a spring or torsion spring system internally, enabling the chair to recline. Some chassis achieve linkage between the seat cushion and backrest through connecting rod structures.
3. Adjusting: It supports operations such as locking the reclining angle and adjusting the reclining tension to meet the needs of different usage scenarios.

II. Characteristics of Different Types of Chassis

1. Ordinary Chassis (Fixed Type): It has a flat-plate structure with no adjustment handles, used only for basic connections. The chair cannot recline and is commonly found in low-priced swivel chairs or bow chairs.
2. Single-Reclining Chassis (Ordinary Tilt): It is equipped with a small wrench or knob on the side, allowing for a 20-30° recline but without angle locking. It is suitable for basic employee chairs.
3. Single-Reclining Chassis with Locking: It features a thick pull rod or hand-operated switch on the side, supporting angle locking for reclining (e.g., 90°, 120°). Some models allow for adjusting the spring tension and are a common configuration in mainstream-priced office chairs.
4. Synchronous Tilt Chassis: It has a sturdy structure with multiple connecting rods. When reclining, the seat cushion and backrest move in proportion (e.g., the backrest reclines by 25°, and the front end of the seat cushion rises by 5°), providing more ergonomic support. It is mostly used in mid-to-high-end products.
5. Cable-Controlled Chassis: All adjustment functions are integrated into a handle, allowing users to operate without bending over. It is commonly found in high-end models.
6. Gravity-Sensing Chassis: It automatically adjusts the reclining resistance based on the user's weight through built-in sensors, providing personalized support. It is a typical configuration for smart office chairs.

III. Precautions for Chassis Disassembly If you need to disassemble the chassis, refer to the following steps (applicable to some models):

1. Remove the screws on the back of the seat plate to separate the seat plate from the base.
2. Lift the fixed iron plate and gently tap the chassis with a hammer to separate it.
3. Invert the base and pry off the snap ring in the middle of the chassis with a flat-head screwdriver.
4. Lift the lift to separate it from the chassis (snap-fit or threaded lifts require specific disassembly methods). Before operating, be sure to refer to the manufacturer's guide or seek professional help to avoid damaging components or causing personal injury due to improper operation.