Compound diaphragm spring

Claim 1

IN AN ELECTROMECHANICAL SEISMIC VIBRATION TRANSDUCER HAVING A SEISMIC ELEMENT MOUNTED ON A RIGID SHAFT BETWEEN TWO DIAPHRAGM SPRINGS, WHEREIN EACH OF THE SIDE DIAPHRAGM SPRINGS COMPRISES A CIRCULAR DISK HAVING A RIM, AN AXIAL HOLE AND PLURAL INVOLUTE GROOVES EACH EXTENDING (A) FROM ONE OF SEVERAL SPACED POINTS LOCATED ADJACENT TO SAID RIM TO (B) ONE OF SEVERAL SPACED POINTS LOCATED ADJACENT TO THE SAID AXIAL HOLE, AN IMPROVEMENT COMPRISING: DEFINING FLAT INVOLUTE RIBBONS EACH CONECTING THE SAID RIM WITH THE CENTRAL PORTION OF THE DISK ANNULARLY ADJACENT TO THE SAID AXIAL HOLE, AN IMPROVEMENT COMPRISING: A SECOND CIRCULAR DISK HAVING A RIM SECURED DIRECTLY TO THE RIM OF THE FIRST SAID CIRCULAR DISK AND HAVING PLURAL FINGERS CORRESPONDING WITH THE SAID INVOLUTE GROOVES AND SAID INVOLUTE RIBBONS, EACH SAID FINGER EXTENDING INWARDLY FROM SAID RIM ACROSS ONE SAID INVOLUTE RIBBON, THENCE ALONG AN INVOLUTE PATH BETWEEN ADJACENT RIBBONS, AND THENCE INWARDLY ACROSS A DIFFERENT ONE OF SAID RIBBONS, THE SAID FINGER BEING RESILIENTLY SECURED TO SAID INVOLUTE RIBBONS AT AT LEAST ONE OF ITS AREAS OF CONTACT WITH A SAID RIBBON.