US-8757283-B2

The aerator features a rotatable tine assembly so as to avoid obstacles or aid in the extrication of the aerator therefrom. The tine assembly includes a plurality of tines mounted about a crank shaft and projecting through said retractor plate. Each tine rod passes between two rollers, one serving as a fulcrum is mounted directly on the retractor plate while the other is mounted upon a spring arm that biases the tine rod as far as possible into a forward position. The aerator is driven by the tines used to puncture the ground.