Patent ID: 8298421

Claim:
A filter device, comprising: a filter housing having an unfiltered fluid inlet, a filtered fluid outlet and a backwash fluid outlet; filter elements in said housing receiving fluid flow in one direction for filtration and in an opposite direction for backwashing effective filter surfaces thereof; a pivoting device mounting said filter, elements in said filter housing for sequential rotational movement about a pivot axis between filtration positions in which unfiltered fluid flows from inside to outside through said filter elements and a backwashing position in which filtered fluid flows from outside to inside through said filter elements, said pivot device having a rotatably mounted receiving part mounting said filter elements parallel to said pivot axis along a path coaxial to said pivot axis and having first and second end parts, said filter elements extending between said end parts, said first end part facing toward said fluid inlet and rotatably guided along an inside of said filter housing by a seal; and a drive being coupled to said receiving part to rotate said receiving part, including a rod-shaped drive part releasably connecting said first and second end parts and including a pneumatic motor producing alternating to and fro movements on an output part convertible into a constant drive movement in a drive direction of said drive part by a free wheel device.