Office Chair Composition Diagram

The composition of an office chair can be divided into three core component systems: the basic structure, support and comfort, and functionality and auxiliary features. However, for a complete composition diagram, refer to the product manual or design guide. Here is a detailed structural analysis:

I. Basic Structural Components

1. Base/Chair Legs
   Typically designed with five claws (star base), with material differences affecting performance: steel chair legs have high bending strength and are suitable for long-term weight-bearing; plastic chair legs are low-cost but prone to aging; aluminum alloy chair legs are lightweight but have a lower weight-bearing limit. Some high-end models are equipped with six-claw or circular bases to enhance stability.
2. Gas Lift (Gas Cylinder)
   Filled with inert gases such as nitrogen, it enables seat height adjustment (with a range of approximately 10-15 cm) and 360° rotation through a control lever. It is important to choose gas cylinders certified by SGS, BIFMA, etc., to avoid the risk of explosion from inferior products.
3. Seat Plate
   Connects the seat cushion to the gas lift, with core functions including weight-bearing (usually supporting 100-150 kg) and tilt adjustment. A single-lever control seat plate can synchronously adjust height and recline angle; a split-type seat plate allows independent movement of the seat cushion and backrest, enhancing comfort.

II. Support and Comfort Components

1. Seat Cushion
   Composed of three layers: the bottom layer is a wooden or plastic board providing support; the middle layer uses high-density foam (density ≥ 45 kg/m³) or molded foam to resist sagging; the top layer is covered with high-elastic mesh fabric (with good breathability) or leather (easy to clean). The waterfall curve design at the front reduces pressure on the thigh veins, preventing numbness from prolonged sitting.
2. Backrest
   Divided into mesh backrests (with strong breathability, suitable for summer use) and foam backrests (with a good wrapping feel). Some models are equipped with independent lumbar supports, such as dual dynamic lumbar support systems that automatically adjust the support angle according to sitting posture; headrests are designed to be adjustable (in height/angle) to fit the cervical spine curve.
3. Armrests
   Fixed armrests have a simple structure but cannot adapt to different body types; adjustable armrests support height (5-10 cm), angle (±15°), and even forward and backward sliding adjustments to meet the needs of typing, reading, and other scenarios.

III. Functional and Auxiliary Components

1. Casters
   Typically with a diameter of 50-65 mm, materials are divided into hard wheels (suitable for carpets) and soft wheels (suitable for wooden floors/tiles). Some models are equipped with brake wheels to fix the seat position and prevent sliding.
2. Elastic Brackets and Rollers
   Used for rotation buffering to reduce friction between the gas lift and the seat plate; some high-end models are equipped with a movement locking function, controlling wheel rotation through a foot pedal switch.

Typical Structural Differences: Executive chairs usually feature high backrests, fixed armrests, steel star bases, and gas lift systems, with fillings of non-high-rebound foam or memory foam; staff chairs, on the other hand, have low backrests, adjustable armrests, and mesh seat cushions, emphasizing breathability and lightness. For detailed structural diagrams, it is recommended to consult the product manuals of specific brands or contact manufacturers for technical drawings.