In operation, sewage flows though the inclined screen, approaching from the upstream side and after passing through the screen, departing on the downstream side. The screen is periodically raked by a mechanized comb system which is actuated either by level switches mounted in the channel upstream of the screen or by time clock. A doctor blade at the top of the comb travel removes the screenings collected by the moving combs.The moving combs are suspended between two endless side chains, which are driven through a head shaft, and sprockets. The gear motor and moving comb system is protected from damage caused by jamming by a torque overload coupling with a micro switch. The screenings removed from the doctor blade drop onto a skid plate, which transports the screening down to a container, belt conveyor or sluice pipe.