Low frequency flextensional acoustic source for underwater use

Abstract

There is provided an acoustic source especially for use in seismic studies at sea. The acoustic source has a longitudinal axis and sound emitting surfaces adapted to be put into sound emitting movements towards and away from each other by use of a drive unit. The sound emitting surfaces comprise two curved plate members having upper and lower ends essentially symmetrically positioned in relation to the longitudinal axis of the acoustic source, and forming a convex cross section with their respective upper and lower edges converging towards each other. The upper and lower edges of the sound emitting surfaces, respectively, are connected to each other with two corresponding side elements, the side elements each being connected to at least one hinge stretching along at least a part of the length of the source. The acoustic source further comprises a rigid frame for supporting the drive unit and comprising at least two rigid slide rods slidingly attached to the side elements with slide bearings for permitting relative axial movement of the slide rods with respect to the side elements. Hinges connected to the side elements provide a direct connection between the upper and lower edges, respectively, of the sound emitting surfaces.

Dependencies are inferred from the claim text.