| 摘要 |
<p>1,198,757. Seismic source. MANDREL INDUSTRIES Inc. 9 Aug., 1968 [18 Sept., 1967], No. 38183/68. Heading H4D. An underwater seismic source comprises an air valve 16 resiliently supported by shockabsorbing blocks 34 in an apertured shell 12. The shell damps oscillations of the air bubble produced by actuating the valve, and the frequency spectrum of the generated seismic signal can be selected by selection of the size and number of the apertures and/or the size of the shell. The apertures may occupy between 11% and 50% of the shell surface area. Compressed air hose 38 and valve-actuating cable 40 may be secured to towing cable 29.</p> |
