Beam-type transducers

Claim 1

STRAIN-RESPONSIVE APPARATUS COMPRISING A TRANSDUCER ELEMENT INCLUDING A SUBSTANTIALLY STIFF ANNULAR RIM, SUBSTANTIALLY COPLANAR FLEXIBLE CANTILEVER BEAM MEMBERS EACH INTEGRAL WITH SAID RIM AT ONE END AND OF THICKNESS LESS THAN THAT OF SAID RIM AND EACH EXTENDING INWARDLY OF THE RIM TOWARD THE CENTER THEREOF FROM A PORTION OF SAID RIM SUBSTANTIALLY DIAMETRICALLY OPPOSITE TO THAT FROM WHICH THE OTHER OF SAID BEAMS EXTENDS, AN ELONGATED SUBSTANTIALLY STIFF STEM DISPOSED AT THE CENTER OF SAID RIM ON AT LEAST ONE SIDE OF SAID COPLANAR BEAM MEMBERS MOVABLE IN DIRECTIONS OF ITS LONGITUDINAL AXIS AND SUBSTANTIALLY NORMAL TO THE PLANE OF SAID RIM, SAID STEM HAVING A PAIR OF SUBSTANTIALLY PARALLEL STIFF BIFURCATED ARM PORTIONS SEPARATED BY A SLOT EXTENDING SUBSTANTIALLY TRANSVERSELY TO SAID BEAM MEMBERS, SAID ARM PORTIONS BEING INTEGRAL WITH DIFFERENT ONES OF SAID BEAM MEMBERS AND BEING FLEXIBLY INTEGRAL WITH THE REMAINDER OF SAID STEM AT DISCRETE FLEXURE SITES ON SAID ONE SIDE OF SAID BEAM MEMBERS, WHICH ARE SUBSTANTIALLY THE SAME DISTANCE FROM THE JUNCTIONS OF SAID STIFF ARM PORTIONS WITH SAID BEAM MEMBERS, SAID ELONGATED STEM HAVING AN OPENING THEREIN WIDER THAN THE SLOT WHICH REDUCES THE THICKNESS OF SAID ARM PORTIONS AT SAID SITES AND THEREBY ACCOMMODATES DEFLECTIONS OF SAID STIFF ARM PORTIONS LATERALLY OF SAID STEM, ELECTRICAL STRAIN GAGE MEANS AFFIXED TO SURFACES OF SAID BEAM MEMBERS FOR DEVELOPING ELECTRICAL OUTPUT SIGNALS RESPONSIVE TO BENDING THEREOF, AND MEANS FOR APPLYING FORCES TO SAID STEM ALONG SAID AXIS AT A POSITION FURTHER REMOVED FROM SAID BEAM MEMBERS THAN SAID FLEXURE SITES.