US Patent 7100622 Pipe scarifier

A scarifier for scarifying an interior surface of a sewer pipe, which includes an elongated frame having spaced apart upstanding frame elements at either end forming a plurality of guide surfaces on each side. A first track extends from one end of the frame to another, reversibly moveable upwardly along a first set of the guide surfaces on a first side of the frame in response to a control signal, which controls a drive system coupled to the track. A nozzle assembly is reversibly moveable along the track from one end of the scarifier to another so that a nozzle, mounted on the nozzle assembly, which emits a jet of fluid towards an interior surface of the sewer pipe, is operative to scarify a swath along the interior surface.