Office Chair and Wheelchair Structure

Office chairs and wheelchairs have distinct structural differences, each featuring unique design characteristics to meet different usage needs.

Office Chair Structural Features

The basic structure of an office chair includes the seat, backrest, armrests, legs, and connecting components.

• Traditional Office Chairs: Their structure resembles Lego blocks, utilizing mortise-and-tenon joints. For example, the Ming Dynasty official's hat chair has its armrests and backrest precisely inserted into holes in the legs without the need for nails. The seat may be made of hardwood or woven rattan, while the backrest is designed in an S-shape to fit the curve of the human waist, providing good lumbar support.
• Modern Office Chairs: These chairs have a more flexible structure, similar to Transformers. The backrest can rock back and forth, the armrests can be adjusted up and down, and the seat is often made of soft foam padding for enhanced comfort. Components are assembled using screws. Some modern office chairs are equipped with wheels, and their stability depends on the wheel-locking mechanism and the weight distribution of the base. Cheaper models may have unreliable wheel locks, while more expensive ones, although equipped with brakes, are rarely used as people seldom apply the brakes when frequently changing sitting positions, leaving the chair in a state of "ready to slide" at any time. Fixed-leg, bow-shaped office chairs, on the other hand, do not have wheels. Their legs are made of a one-piece, bow-shaped steel base without welds, evenly distributing pressure across the entire frame when under load. The bottom crossbeam is reinforced and equipped with non-slip feet, providing excellent stability when seated.

Wheelchair Structural Features

The structure of a wheelchair is relatively complex, involving multiple stages such as design, material preparation, component fabrication, assembly and fixation, installation of other components, and debugging and testing.

• Design Stage: Workers use computers to draw design plans, specifying the dimensions and structures of various parts such as the seat, armrests, and wheels.
• Material Preparation: Lightweight yet sturdy aluminum alloy is commonly used as the material.
• Component Fabrication: Machines are used to cut materials, and molds and extruders are employed to form the desired shapes and structures. For the seat, workers cut materials according to the design pattern and stitch them together using sewing machines to create seat cushions, paying attention to details to ensure quality and comfort.
• Assembly and Fixation: Various components are welded together to ensure a sturdy frame. The chassis support structure and frame are assembled, the seat support is installed and fixed with screws, and the armrests are installed to provide stable support and comfortable grips.
• Installation of Other Components: Wheels and bearings are installed to ensure the wheels can rotate freely and are securely fixed. Brakes and footrests are installed and firmly attached to the chassis to effectively control the wheelchair's stopping and movement.
• Debugging and Testing: The assembled wheelchair undergoes debugging and testing to ensure it is problem-free before completion. Additionally, wheelchairs can be classified into electric and manual types based on their drive mechanism. Hand-cranked wheelchairs add a hand-cranking device to the basic structure of a regular wheelchair, while smart wheelchairs incorporate positioning and standing movement functions on the basis of electric wheelchairs.