Zengerle, R.R.ZengerleRichter, A.A.Richter2022-03-082022-03-081995https://publica.fraunhofer.de/handle/publica/303183A microminiaturizable valve comprises a pressure equalizing chamber, a first semi-active valve which is arranged between the pressure equalizing chamber and a first fluid line, and a second semi-active valve which is arranged between the pressure equalizing chamber and a second fluid line.de608621patent1992-4227998