US Patent 7278449 Switch, especially for branching off bulk material flows

The invention relates to a switch for branching off bulk material flows, the switch includes a rotary plug (1) which is arranged in a fixed housing having preferably three connection openings. In a first position the plug establishes a connection between a first pair of connection openings and, by rotation into a second position, establishes a connection between a second pair of connection openings, a gap being provided between the rotary plug (1) and the housing in such a way as to arrange the rotary plug (1) in the housing in a non-contact manner without any additional contact sealing elements. The plug (1) and/or said housing includes at least one labyrinth sealing arrangement (7).