Ultrasonically bonded valve assembly

摘要

A valve apparatus capable of maintaining a fluid tight seal over a relatively long period of time by releasably bonding a valve member to its seat is provided. The valve member is bonded or welded to the seat and then released by the application of the same energy to the bond joint. The valve member can be hollow to incorporate an ultrasonic bonding unit having an appropriate transducer. The valve member is held in place during the bonding by a clamping device. An appropriate force device can activate the opening and closing of the valve member. The choice of materials for the valve member and valve seat preferably provides an adequate sealing bond with little adhesion of material when the bond joint is broken for opening the valve member. Various combinations of material for the valve member and valve seat can be utilized such as a hard metal or ceramic with poor adhesion characteristics and a soft metal. Some illustrative materials are aluminum oxide, stainless steel, inconel, tungsten carbide as hard materials and copper, aluminum, titanium, silver, and gold as soft materials.