Piezoceramic valve actuator sandwich assembly and valve incorporating such an assembly

Claim 1

A valve comprising: a valve actuator sandwich assembly comprising; a piezoceramic bending element having a first side and a second side and including means for electrically activating the piezoceramic bending element; first and second metal sheets flexibly bonded to the first and second sides of the piezoceramic bending element, respectively; first and second flexible elastomeric sheets bonded to outer surfaces of the first and second metal sheets, respectively; a first supporting member which sealingly engages an outer surface of the first elastomeric sheet in a continuous line around a periphery of a central portion of the first elastomeric sheet to flexibly support a first side of the valve actuator sandwich assembly and to create a first valve chamber between the central portion of the elastomeric sheet and the first supporting member; a second supporting member which sealingly engages an outer surface of the second elastomeric sheet in a continuous line around a periphery of a central portion of the second elastomeric sheet to flexibly support a second side of the valve actuator sandwich assembly; a valve inlet communicable with the first chamber; a valve outlet communicable with the first chamber; and at least one of the valve inlet and the valve outlet including a valve seat having an orifice therethrough sealingly engageable with the central portion of the first elastomeric sheet to prevent a stream of flow through the valve seat, first chamber, valve inlet and valve outlet, the valve seat being disengageable from the first elastomeric sheet to allow the stream of flow through the valve seat, first chamber, valve inlet and valve outlet; wherein the flexible supporting of the valve actuator sandwich assembly by the first and second supporting members allows deflection of the valve actuator sandwich assembly when the piezoceramic bending element is actuated; and the sealing engagement of the first and second supporting members with the first and second elastomeric sheets, respectively, also causes a sealing engagement between the first and second elastomeric sheets and the first and second metal sheets, respectively, and thereby isolates the piezoceramic bending element from the flow stream.