A lawn aerator has a series of tine assemblies spaced along a driven shaft driven by a motor. Each fine assembly has a plurality of tines for aeration extending in a substantially radial pattern about the driven shaft. The inner tine assemblies along the middle portion of the driven shaft...http://www.google.de/patents/US5680903?utm_source=gb-gplus-sharePatent US5680903 - Lawn aerator having tine assemblies spaced along a shaft
