| 摘要 |
<p>1,120,601. Generating seismic waves. E.G. & G. Inc. 19 Oct., 1965 [18 Jan., 1965], No. 44265/65. Heading H4D. [Also in Division H1] An underwater sound producing system comprises an insulated electrode 10 having a small area exposed to the water and an uninsulated electrode 20 connected across a supply source and spaced apart by a distance which is just greater than the maximum expansion of the plasma bubble caused by a spark discharge from said small exposed area. The electrode 10 may project from the sleeve 15, as shown, or may be flush therewith. The thickness of the sleeve 15 is predetermined so as to wear away at the same rate as erosion of the electrode occurs under the action of the sparking. The electrode may be of brass and the sleeve of moulded neoprene or of other insulating materials, e.g. polyurethane, nylon, or epoxy resins, with good bonding qualities. With these materials the thickness of the sleeve should be approximately equal to the radius of the electrode. The outside diameter of the sleeve may be from 1¢ to 3 times the diameter of the electrode. A waterproof plug may be moulded integrally with the sleeve 15 to permit rapid replacement of a worn-electrode. In an alternative embodiment (Fig. 4, not shown) three insulated electrodes are mounted along the axis of a triangular prismatic cage uninsulated electrode.</p> |
