Filtering arrangement for internal combustion engines

Claim 1

A filter arrangement for internal combustion engines, especially for filter fuel and oil, which includes: filter housing means, at least two filtering units arranged in said filter housing means, a plurality of filtering inserts respectively arranged in said filtering units for receiving the medium to be filtered between said filtering inserts and the interior of the pertaining filter housing means, said filtering arrangement being provided with an inlet connection common to all filtering units and with an outlet connection common to all filtering units, said filtering arrangement also being provided with a discharge connection communicating with the lowermost areas of the interior of said filter housing means, change-over valve means built into said inlet and outlet connections and operable selectively to place said filtering units individually and together into and out of communication with said inlet and outlet connections and with said discharge connection, and shut-off valve means associated with said change-over valve means and operable to establish communication of the interior of said filter housing means pertaining to that filter unit which is disconnected from said outlet connection with said discharge connection, said change-over valve being designed as a rotary valve comprising a star wheel for said inlet connection and a star wheel for said outlet connection, said change-over valve being provided with a bore having an inner end communicating with said discharge connection, first and second conduit means for respectively establishing communication between said inner end of said bore with said discharge connection and between said inner end of said bore and the interior of said filter housing means, and spring-loaded check valve means respectively arranged in said first and second conduit means and continuously urged to their closing positions, said check valve means being movable by said change-over valve to its open position.