A faucet has a body with a hollow inner cavity and a spout which opens into the inner cavity. A valve assembly is located within the inner cavity to control the flow of water from a source into the spout. The valve assembly comprises a housing with an inlet chamber which opens into a ring-shaped channel,...http://www.google.de/patents/US4915347?utm_source=gb-gplus-sharePatent US4915347 - Solenoid operated faucet
