A multiple valve assembly for use in the medical field includes a pair of flexible valve discs which are essentially co-planar with each other. A pair of tube connectors are oriented to be at an essentially right angle with respect to each other, and fluid communication between the interior of a hollow...http://www.google.es/patents/US4246932?utm_source=gb-gplus-sharePatente US4246932 - Multiple additive valve assembly
