Noise-preventing structure for water mixing cocks

Claim 1

A water mixing cock having a noise-preventing structure, comprising: a valve case; a fixed plate mounted in said valve case, said fixed plate having a hot water passage and a cold water passage therethrough; a movable plate valve having a cut-off surface disposed in opposition to and slidable with respect to the fixed plate; a hollow chamber being formed in the movable plate valve and having an inlet portion for selectively interconnecting said hot water passage, said cold water passage or both passages with said hollow chamber; a sound arresting member disposed in the inlet portion of the hollow chamber; valve operating means, arranged in contact with the fixed plate and the movable plate valve, for moving the movable plate valve to allow passage of hot water, cold water, or mixed hot and cold water through said inlet portion into the hollow chamber; a discharge water passage arranged in communication with the hollow chamber; and a variable escape groove means, cut into the cut-off surface of the movable plate valve, for communicating the hollow chamber and the cold water passage in the fixed plate with each other when the inlet portion of the hollow chamber is in fluid communication with only the hot water passage in the fixed plate; whereby noise occurring when the movable plate valve is moved by the valve operating means is minimized.