Aerator having flexible frame

An aerator comprising:

• a coring head having a plurality of tines that move by a reciprocating motion to repeatedly penetrate a ground surface;
• a flexible frame on which the coring head is mounted;
• the flexible frame having a horizontal pivot axis;
• and
• a flex frame actuator to flex the frame on the horizontal pivot axis in response to signals from a ground sensor so that the tines penetrate the ground surface at an angle that is perpendicular to the ground surface.

An aerator comprising:

• a pair of frame sections linked together at a horizontal pivot axis;
• one of the frame sections supporting a coring head;
• a ground sensor pivotably attached to one of the frame sections so that the ground sensor pivots in response to changes in slope and provides an electronic signal relating to the magnitude of the change;
• and
• an electronic control unit receiving the electronic signal and using that electronic signal to provide commands to a flex frame actuator that pivots the pair of frame sections with respect to each other.