Capacitive pickup devices

Claim 1

A VARIABLE PRESSURE DETECTING DEVICE COMPRISING AN ANNULAR FIRST BLOCK HAVING AN OUTER SURFACE AND AN INNER SURFACE DISPOSED COAXIALLY WITH THE CENTER AXIS OF SAID BLOCK, SAID INNER SURFACE DEFINING A CHAMBER THE PRESSURE IN WHICH IS TO BE DETECTED, A CYLINDRICAL SECOND BLOCK HAVING AN OUTER DIAMETER SUBSTANTIALLY EQUAL TO THE OUTER DIAMETER OF SAID FIRST BLOCK, SAID BLOCKS BEING SUPERIMPOSED AND THE ADJACENT SURFACES DEFINING SURFACES OF REVOLUTION DISPOSED SYMMETRICALLY IN REFERENCE TO SAID CENTER AXIS, A DIAPHRAGM CLAMPED BETWEEN SAID ADJACENT SURFACES AND SEALING SAID CHAMBER, SAID DIAPHRAGM CONSTITUTING A FLEXIBLE FIRST ELECTRODE OF A CAPACITOR, THE DIAPHRAGM BEING DEFLECTED IN ACCORDANCE WITH THE PRESSURE IN SAID CHAMBER, SAID SECOND BLOCK INCLUDING A RECESS IN ITS SURFACE FACING THE FIRST BLOCK AND A BORE EXTENDING FROM THE BASE OF SAID RECESS, SAID RECESS AND SAID BORE BEING DISPOSED COAXIALLY WITH THE CENTER AXIS OF THE FIRST BLOCK, AND A RIGID ELECTRODE OF THE CAPACITOR, SAID SECOND ELECTRODE INCLUDING A CYLINDRICAL PLATE MEMBER AND A CYLINDRICAL SHANK MOUNTING SAID PLATE MEMBER AND FITTED IN SAID BORE, THE SIDE OF SAID PLATE MEMBER FACING THE DIAPHRAGM BEING CONCAVE IN REFERENCE TO THE DIAPHRAGM.