Piezoelectric pressure transducer

Claim 1

A PRESSURE TRANSDUCER HIGHLY IMMUNE TO SPURIOUS NOISES, AND ESPECIALLY USEFUL AS THE AUSCULTATORY DETECTOR OF A SPHYMOMANOMETER, THE SAID TRANSDUCER COMPRISING: A HOUSING OF WAFERLIKE CONFIGURATION HAVING A RECESS LOCATED CENTRALLY IN ONE SIDE, AND A RIM HAVING ON THE SAME SIDE AS THE RECESS OPENING AND ENDLESS SURFACE OF SUBSTANTIAL WIDTH FOR ENGAGING A PRESSURE TRANSMITTING MEDIUM; A DIAPHRAGM DISPOSED OVER THE OPENING OF THE RECESS; A FLAT PIEZOELECTRIC CRYSTAL HAVING OUTER DIMENSIONS SOMEWHAT LESS THAN THE INNER DIMENSIONS OF THE RECESS, AND DISPOSED WITHIN THE RECESS WITH ONE FLAT SURFACE IN CONTIGUOUS RELATION WITH THE INNER SURFACE OF THE DIAPHRAGM; MEANS IN THE UNOCCUPIED SPACE OF THE RECESS FOR ENHANCING THE TRANSDUCTION OF MECHANICAL ENERGY FROM A PRESSURE TRANSMITTING MEDIUM IN CONTIGUOUS RELATION WITH A CENTRAL PORTION OF THE DIAPHRAGM INTO AN ANALOGOUS ELECTRICAL SIGNALS; AND MEANS COUPLED TO THE CRYSTAL FOR CONDUCTING ELECTRICAL SIGNALS DEVELOPED BY THE LATTER TO UTILIZATION APPARATUS.