29. Kết cấu khí và lỏng

Nguyên tắc con

1. Use a gas or liquid in place of solid parts to do the work

Ví dụ

• An air-cushioned sole
• A hydraulic brake
• An air-flotation conveyor

Ứng dụng theo lĩnh vực

• mechanical: Raising a heavy car with a screw jack is slow and hard work. In a hydraulic jack, pushing a small piston drives oil that lifts a large one.
• medical: A rigid splint does not fit a swollen injured leg. An inflatable splint takes the shape of the leg and grips it evenly.
• everyday: Items shift in a shipping box and break. Filling the gaps with air-filled plastic cushions holds them lightly in place.
• materials: Pushing a plastic part out of a mold with ejector pins leaves marks. A blast of compressed air releases it instead.