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.

Abstract: Acoustic source, especially for use in seismic studies at sea, with sound emitting surfaces adapted to be put into sound emitting movements toward and away from each other by use of a drive unit in a known manner, in which the sound emitting surfaces comprise two curved plate members essentially symmetrically positioned in relation to the longitudinal axis of the source, forming a convex cross section with their respective upper and lower edges converging towards each other, and the respective upper and lower edges of the sound emitting surfaces are flexibly connected to two corresponding side elements positioned between them, and that the source comprises a rigid frame for supporting the drive unit, comprising at least two rigid slide rods stretching through the side elements, and that rigid covers are mounted on the slide rods, covering at least the whole side elements, thus forming rigid, covering surfaces with a constant distance between the covers.

Abstract: Drive assembly for acoustic sources with vibrating surfaces (1) capable of being set in vibrational motion, especially for use in seismic studies, comprising a frame (4) comprising at least one preferably centrally positioned drive part (3, 13). The drive assembly also comprises: two or more fastening devices (2) mounted in relation to the sound emitting surfaces (1) and positioned on opposite sides of the frame (4); two or more flexible transmission elements (5) connecting the fastening devices (2) to each other and extending on both sides of the axis between the two fastening devices;5 two or more second drive parts (6, 7, 16, 17) connected to the transmission elements (5) and positioned in cooperation with said first drive parts (3, 13) in order to make electromagnetic drives; and that each of the electromagnetic drives are adapted to provide a controlled oscillating relative motion between the related drive parts (3, 6, 7, 16, 17).