Crystal pressure sensitive geophones for use in soft earth

Claim 1

A HIGH SENSITIVITY PRESSURE TYPE GEOPHONE FOR USE IN MARSHY AREAS AND THE LIKE COMPRISING A LONG RELATIVELY NARROW HOUSING HAVING A CENTRAL BODY PORTION DEFINING A LONG NARROW OPENING THEREIN, A PAIR OF PIEZOELECTRIC UNITS, GASKET MEANS FOR MOUNTING SAID PIEZOELECTRIC UNITS ON OPPOSITE SIDES OF THE NARROW DIMENSION OF SAID CENTRAL BODY PORTION ENCLOSING SAID LONG NARROW OPENING THEREIN, A PAIR OF RECTANGULAR FRAMES COMPLETING SAID HOUSING FOR HOLDING SAID PIEZOELECTRIC UNITS IN PLACE, SAID PIEZOELECTRIC UNITS EACH COMPRISING A LONG RECTANGULAR FLAT FLEXIBLE DUCTILE MATERIAL DIAPHRAGM HAVING A THICKNESS OF BETWEEN 0.007 INCH AND 0.064 INCH AND A LONG THIN, FLAT, FLEXIBLE PIEZOELECTRIC CRYSTAL OF SUBSTANTIALLY THE SAME LENGTH AND WIDTH AS THE FREE AREA OF THE INWARD FACING SURFACE OF SAID DIAPHRAGM, MEANS FOR ADHESIVELY BONDING ONE ENTIRE FACE OF SAID CRYSTAL TO THE FREE AREA OF THE INWARD FACING SURFACE OF SAID DIAPHRAGM, MEANS FOR MAKING ELECTRIC CONNECTIONS TO OPPOSITE FACES OF SAID PIEZOELECTRIC CRYSTAL, MEANS IN SAID HOUSING FOR PERMITTING PRESSURE WAVES IN SAID MARSHY AREAS TO IMPINGE ON THE OUTWARD FACING SURFACE OF SAID DIAPHRAGM TO CAUSE FLEXURE OF SAID DIAPHRAGM AND CORRESPONDING FLEXURE OF SAID CRYSTAL THEREBY PRODUCING CORRESPONDING VOLTAGE VARIATIONS AT SAID ELECTRIC CONNECTION MEANS.