Air caster

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Animation of how an air caster operates. Blue represents compressed air, purple represents the air film (or cushion) that the device rides on.
Animation of how an air caster operates. Blue represents compressed air, purple represents the air film (or cushion) that the device rides on.

An air caster is a pneumatic lifting device used to move heavy loads on flat, non-porous surfaces. Its operation is similar to a hovercraft, in that it uses a thin layer of air as a way to float a very small distance off the ground. Compressed air enters an airbag shaped like a torus[1] (or donut), when the bag is filled two things happen:

  1. The bag creates an airtight seal with the ground, thus accumulating greater amounts of air with no means of escape.
  2. More and more gas is forced into space inside the torus center, eventually pushing its way under the airbag as a thin film of air lifting the whole unit off the ground.

The compressed air is forced under the airbag, pushing it and the load less than a millimeter off the ground.[2]

[edit] Limitations

Air casters require a smooth, non-porous surface in order to maintain lift and operate properly. Cracks and other surface defects can interrupt the proper flow of air causing the air cushion to dissipate and thus lose its ability to lift. This limits their application to fields like manufacturing, where such surfaces are abundant. Also necessary is connection to a system which provides compressed air, as well as a power supply.

[edit] References

  1. ^ FAQ from company that manufactures air casters, describing their operation.
  2. ^ FAQ from company that manufactures air bearings, a component of the air caster, describing their operation.