Patent ES-8405575-A1 (ES)
Title: Electroacoustic reed hydrophone
IPC: H04R9/00
Filed: 1983-07-18
Abstract: EP--98017 A Preferably, there are four such reeds (34,36,38,40) disposed in a respective quadrant of the base (22) of the hydrophone and cantilevered from the base. The topmost edge of each reed is received in a respective groove of the associated weight (60,62, 64,66). Sound waves incident upon the hydrophone produce radially-diverted forces in its cylindrical wall which is normal to waves from all directions. - The force produced is a function of the wall area upon which the wave is incident. The force causes displacement of the base (22) relative to the inertial weights and, consequently, produces the bending of the reeds. Electrical signals representing the bending moement applied to a respective reed are carried by leads through apertures in the base to a directional signal processor.  (4/7) EPAB- EP--98017 B Electroacoustic transducer apparatus for suspension in a liquid acoustic medium comprising: a rigid support base (22) having a support surface, and having a wall (32) extending outwardly from said surface; a flexible, planar, resilient reed (34) having an electroacoustic transducer laminate (72,74) on at least one side thereof to convert between an electrical signal and a corresponding acoustic wave; said reed having a first edge (34a) and a second edge (34b) opposite to said first edge; said reed being cantilevered from said support base (22) at said first edge (34a) and extending outwardly from said surface; characterized in that the apparatus comprises an inertial weight (60), said weight (60) being affixed to said reed in spaced relation from said first edge to form a weighted transducer reed (34,60); said weight (60) being movable relative to said base in a direction that has a transverse component to the plane of said reed (70) whereby sound waves impinging on said wall (32) and having a directional component transverse to the plane of said reed will cause relative transverse movement between said base (22) and said weight (60) to apply a bending moment to said reed (34), means for suspending said base in a liquid acoustic medium so that said base is not supported by a solid surface and so that said base can move in said medium in correspondence with acoustic waves impinging the area of said wall. - (11pp) - EP--98017 B Electroacoustic transducer apparatus for suspension in a liquid acoustic medium comprising: a rigid support base (22) having a support surface, and having a wall (32) extending outwardly from said surface; a flexible, planar, resilient reed (34) having an electroacoustic transducer laminate (72,74) on at least one side thereof to convert between an electrical signal and a corresponding acoustic wave; said reed having a first edge (34a) and a second edge (34b) opposite to said first edge; said reed being cantilevered from said support base (22) at said first edge (34a) and extending outwardly from said surface; characterized in that the apparatus comprises an inertial weight (60), said weight (60) being affixed to said reed in spaced relation from said first edge to form a weighted transducer reed (34,60); said weight (60) being movable relative to said base in a direction that has a transverse component to the plane of said reed (70) whereby sound waves impinging on said wall (32) and having a directional component transverse to the plane of said reed will cause relative transverse movement between said base (22) and said weight (60) to apply a bending moment to said reed (34), means for suspending said base in a liquid acoustic medium so that said base is not supported by a solid surface and so that said base can move in said medium in correspondence with acoustic waves impinging the area of said wall. (11pp) USAB- US4709359 A A cylindrical shell enclosure accommodates, in cantilever manner, four upstanding laminated planar flexible resilient electro-acoustic transducer reeds. A separate inertia weight is affixed to the top edge of each reed. - An acoustic wave impinging on the side wall of the submered enclosure will cause relative movement between the enclosure and a weight if the wave direction has a component transverse to the plane of the reed on which the weight is mounted. The reeds are mounted in quadrature so that wave direction detection is provided by comparing the electrical outputs of the reeds. Visco-elastic damping pads may be affixed between the side ends of each of the weights and respective upstanding rigid arms secured to an interior surface of the enclosure.