Abstract: A piezoelectric capsule with resilient conducting holding means is disclosed, comprising a hollow metal lid (8) fitted on a base body (7) formed of a printed circuit, and a piezoelectric membrane (1) applied against a front step (17) of the lid (8). A resilient electrically conducting element (22), fixed to the base body (7), bears on the metallized external rear face (5) of the piezoelectric ceramic layer (3) of the membrane (1). The resilient element (22) provides simultaneously electric conduction and mechanical holding of the membrane (1) in position.

Abstract: A piezoelectric capsule with flat supporting surface and resilient holding means is disclosed, comprising a hollow metal lid (8) fitted on a base body (7) formed of a printed circuit, and a piezoelectric membrane (1) applied against a front step (17) of the lid (8). The resilient holding means (22), fixed to the base body (7), bear on the central zone of the rear face (5) of the membrane (1). The resilient means (22) hodl the membrane (1) mechanically in position and simultaneously provide peripheral sealing by the fact that the corresponding surfaces of the front step (17) and of the membrane (1) are perfectly flat.

Abstract: A piezoelectric insert is provided comprising a membrane (1) formed from a substrate (2) and two piezoelectric material layers (3, 4) whose external surfaces are metallized so as to form the electrodes (5, 6). The membrane comprises a radial excrescence (15) whose upper and lower faces are nipped between the clip shaped legs of connectors (22, 23). The electric connection of the electrodes thus requires no soldering.

Abstract: The present invention provides an insert (1) forming an independent assembly of a coil body (15). The electroacoustic transducer comprises an insert (1) formed of a case with a vibrating membrane (2) and its electric connectors (4, 5) and a coil body (15) distinct and separable from the insert. The coil body can be fitted to the rear face (14) of the insert and comprises axial passages (20, 21) through which the insert connectors (4, 5) pass. Contact pieces (22, 23) provide the electric connection of the coil with the insert connectors.

Abstract: A telephone set-computer terminal assembly is provided having a single decimal keyboard and a switchable local supply. The telephone interface, connected to the decimal keyboard, is supplied by its line input through a switching relay which connects it at one time to a local power supply of the man-machine interface equipment and at another to the line through a switch depending on whether the line is unlooped or not. The telephone interface is connected to the man-machine interface equipment by message communication lines comprising a galvanic insulation device.