Air caster

File:Aircaster.gif

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, as 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, and when the bag is filled it creates an airtight seal with the ground, and forces more air into the centre of torus, eventually causing the air to flow over the bag and to raise the load above the ground.

The compressed air is forced under the airbag, pushing it and the load less than a millimetre off the ground.

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.

Usually, a standard concrete warehouse or factory floors provide an adequate surface. Some large cracks and filling expansion joint repairs may be required. Overlay material can provide options for moving over rough surfaces. (Example: You can use an overlay material to move onto an area of broom finished concrete outside. The overlay material can be sheet metal or a heavy gauge plastic sheet material.)