(1) Field of the Invention
The invention relates to wired transmissions systems, and more particularly to an underwater acoustic receiving system installation in a diving helmet.
(2) Description of the Prior Art
Acoustic receiving systems are commonly employed by the Navy in underwater reconnaissance, studies of submerged vessels, and other oceanographic concerns. A miniature sonar receiving system, typically referred to as a "pinger", is used by divers for locating torpedoes or other underwater devices in which transmitters are installed. The transmitters emit an acoustical signal which is received by the pinger receiver, amplified, sent through insulated electrical wires, and reproduced as an audible beep by an earphone located near the diver's ear.
The extreme underwater environments in which such operations occur prohibit convenient and extended utilization of acoustic receiving equipment in even the most routine of applications. For example, reconnaissance operations frequently take place at depths of up to two hundred feet and more. At such depths pressure may exceed 44 pounds per square inch. Where such operations are conducted throughout the year, the diver must assail the water during winter months in which water temperatures can dip as low as 29 degrees Fahrenheit. The present operating procedure for underwater reconnaissance operations using an acoustic receiver system involves use of an earphone attached to the diver's head, with lead wires extending down an underwater garment sleeve and under the cuff to the hand-held pinger receiver. This practice tends to allow water leakage into the dry suit and to thus subvert the whole purpose of using the helmet in combination with a dry suit, and results in the diver's underwater exposure being limited to ten or fifteen minute intervals in many cases. The present procedure of attaching the earphone to the diver's head is also unsatisfactory because the holding strap tends to slip down over the diver's eyes, obstructing his vision, or interfering with the separate communications speaker, which is connected through air cables to the dive boat.
Moreover, the haphazard location of wires from the acoustic receiving system interferes with the diver's use of certain deep-sea diving helmets, such as the Navy MK-12 helmet used by the U.S. Navy. Diving helmets such as these are necessarily compact because of their heavy brass construction and require the diver to move his head in order to view objects that are not located directly in front of him.
In view of the foregoing difficulties, a modification is needed for providing installation of an underwater acoustic receiver system in a deep-sea diving helmet, so as to improve the level of safety to the diver and to permit convenient use of such a system for reasonable periods of time in harsh underwater environments.