Acoustic sensor
AssigneeInnovative Transducers Inc.
InventorRichard E. Pearce
Life of this patent
Estimating the term…
Abstract
A pressure compensated hydrophone assembly consists of a hollow mandrel that has an outer surface. The central portion of the outer surface of the mandrel defines a concavity. A flexible, resilient piezoelectric film is wrapped several times around the mandrel. The volume between the inner wrap of the film and the concavity on the outer surface of the mandrel serves as a pressure compensation chamber. The hydrophone is responsive to varying hydrodynamic pressure fields but is substantially inert to acceleration forces, localized impacts and variations in hydrostatic pressure.
Claims13
A hydrophone assembly, comprising:
- a hollow mandrel having a concave outer surface;
- a flexible piezoelectric element, including inactive opposite edge portions wrapped a plurality of times in successive superimposed wraps around the outer surface of said mandrel, there being at least an inner wrap and an outer wrap;
- means for insulating each wrap one from the other;
- and
- means for hermetically sealing the inactive edge portions of said piezoelectric element to the outer surface of said mandrel.
A pressure compensated hydrophone assembly, comprising:
- a hollow mandrel having an outer surface and a length equal to a predetermined multiple of its diameter, the central portion of said outer surface defining a concavity;
- a flexible piezoelectric element having inactive edge portions that are laterally spaced apart by an amount equal to the length of said mandrel, wrapped a plurality of times around said mandrel, there being an inner wrap, intermediate wraps and outer wrap having an exposed end portion, said flexible piezoelectric element being electrically responsive to tensile stresses due to uniformly distributed transient acoustic wavefields applied radially thereto;
- an insulating film separating each said wrap;
- and
- a volume of air enclosed between the outer surface of said mandrel and said inner wrap.
A pressure compensated hydrophone assembly, comprising:
- a hollow mandrel;
- an air-backed multilayered flexible piezoelectric element hermetically sealed externally around said hollow mandrel, said resilient piezoeleotric element producing electrical output signals in response to tensile stresses due to uniformly-applied hydrodynamic pressure transients, said flexible piezoelectric element further being substantially electrically inert to acceleration forces, to localized mechanical forces and to variations in hydrostatic pressure.
Dependencies are inferred from the claim text.