Cleaning of an air filter screen of an agricultural vehicle

摘要

A method and apparatus are disclosed for unblocking a perforated rotary filter screen. In the invention, at least one jet of high pressure air is directed at a surface of the filter screen as the filter screen is rotated and the or each jet of air is moved in a direction transverse to the direction of movement of the perforations in the screen in order to cause the or each air jet to trace a spiral or helical path over the surface of the screen.