Sanding machines having a variety of different actions are available. For example, a simple disc sander rotates a sanding disc on the surface of a work piece. Drum sanders rotate a cylindrical drum supporting a strip of sandpaper. Belt sanders drive a sanding belt around a predetermined path, and produce an action similar to a drum sander. Orbital sanders are available which provide a flat plate on which a sheet of sandpaper is supported, with a plate being rapidly moved around an orbital path on a work piece. All of these different sanding machines have attendant disadvantages. Disc sanders are difficult to control, and have a tendency to gouge a work piece surface, and produce uneven results. The sanding discs break down rapidly. Drum sanders and belt sanders are usually used for hardwood floor surfaces. They too have disadvantages in that they produce only a line contact (i.e. tangent to the drum,) between the sanding sheet and the surface, and again they tend to produce uneven results, especially where there are variations in the grain of the wood. Orbital sanders are in wide use by hobbyists. However, these sanders are usually hand held appliances, and produce a fairly strong vibration. Consequently they are not suitable for extended use.
When sanding it is desirable to provide a linear to and fro action, and to provide a sanding action extending over a significant surface area so that the sanding action will be uniform over the whole area of the work piece. At the same time, it is desirable to provide such a linear action sander in which vibration is substantially eliminated, so that it, and, if needed, hand held, may be used for extended periods of time without causing health problems.
However, a single plate linear movement sander would experience severe vibration problems, which would be greater than the vibration problems inherent in the orbital type of plate sander. Consequently such a system would be impractical.