摘要 |
The desired groove shape in a backplate of a combination transmitting and receiving, capacitance type, electrostatic transducer are more consistently reproduceable in a die forming operation by utilizing an open ended grooved configuration so that groove shape deforming lubricating fluid, necessary in said die forming operation, and air, can escape from between the die tool and the transducer backplate through said open ended grooves as said grooves are die formed on said backplate. |