Ammunition and explosives – Mines – Counter measure
Reexamination Certificate
2000-04-07
2001-09-11
Jordan, Charles T. (Department: 3644)
Ammunition and explosives
Mines
Counter measure
C089S001130
Reexamination Certificate
active
06286431
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to minesweeping equipment, and more particularly to equipment that will clear a shallow body of water of mines that can be set off by influence signatures.
BACKGROUND OF THE INVENTION
A minesweeping system that creates influence signatures generally must provide a large enough influence field to be effective while still minimizing the size and weight of the equipment to make the system practical from the standpoint of the platform which controls and/or tows the system. This platform may be a ship, a helicopter, a remote controlled vehicle operating above or below the water surface, or a slow moving aircraft. Minesweeping systems to date have therefore involved a trade-off of performance vis-a-vis size and weight.
Prior art systems to date have included sweep systems using open loop magnetic technology, wherein electrical current is distributed between two or more towed electrodes and the intervening seawater between the multiple electrodes is used as the electrical return. One such system, the Mk-105, utilizes a hydrofoil vehicle towed by a helicopter with a gas turbine power plant on the hydrofoil to generate electricity for the open loop electrodes. The Mk-105 system is powerful, but also quite large and heavy, thus requiring the hydrofoil vehicle. In general, however, the most efficient means to achieve a large magnetic field is to use the open loop means of generating the field. Thus, a ship or helicopter-hydrofoil system has generally been required for the towing. Further, such open loop systems require sufficient physical handling equipment to handle the two or more electrodes, including the appropriate deployment and retrieval of the multiple electrodes as well as maintaining the multiple electrodes separated from one another for proper functioning and to avoid tangle.
An alternative prior art sweep system, for example the SWIMS system, generates the magnetic influence field utilizing conventional dipole technology with large magnetic cores. Because of the size and weight associated with this technology, however, the magnetic field is limited by the size and weight of a practical towed body in which the system is housed.
Still further prior art minesweeping systems have involved various coils or permanent magnet solutions which also have size and weight problems that result in limited field strength.
Various prior art minesweeping and other marine systems are also illustrated in U.S. Pat. Nos. 2,393,466; 2,937,611; 3,060,883; 3,273,110; 3,938,459; 3,940,732; 4,562,789; 4,627,891; 4,697,522; 5,001,485; 5,063,850; 5,323,726; and 5,941,744.
SUMMARY OF THE INVENTION
The present minesweeping invention is intended to utilize the open loop means of generating the magnetic field to obtain a powerful field, while overcoming the deficiencies of the prior art to provide a smaller system, a lightweight system, and a system that simplifies electrode handling. The present invention is sufficiently small and stable that it can be utilized with and towed by smaller helicopters, smaller water vehicles or remotely operated vehicles. The invention is particular adapted to littoral operation, for example to clear mined ports or offshore areas or off a beachhead where it is desirable to minesweep the shallow waters in preparation for landing craft.
The present invention includes a body to be towed in the water, the body containing hydrodynamic control surfaces and designed to provide a high-speed and stable tow. The body provides the means to generate the magnetic influence signatures, and the body may also include transducers to generate acoustic influence signatures. A significant aspect of the present invention is that the towed body does not tow multiple electrodes to generate magnetic signatures, but rather only tows one (the first) electrode while still using an open loop means of generating the magnetic field. This is accomplished by having the towed body function as the other (the second) electrode, either by making the skin of the body the electrode, or by having removable electrode panels on the skin of the towed body, or perhaps by incorporating pieces of standard electrode designs into the body. Thus the towed body only has one cable which contains the first electrode extending behind the towed body. The physical handling equipment for the single cable is thus considerably simplified as contrasted with what is needed for open loop systems handling and towing multiple cables, each with electrodes.
Open loop power and control systems generally provide an input AC power which is then rectified to DC power and controlled to either continuous level or to relatively low frequency (pulsed) waveforms. This rectification and conditioning generally are done on the primary towing platform, i.e., the helicopter or ship, which requires weight and space, and requires large diameter cables to handle and pass the large DC currents associated with open loop sweeps. Particularly when the primary towing vehicle is a helicopter, the cable with DC power from the helicopter to the towed body is in air and thus presents difficulties in cooling absent such a large diameter cable. Accordingly, in a further aspect of the present invention, AC input power of low amperage and high voltage is passed from the primary towing platform to the towed body, enabling the use of a lower weight cable of small diameter that can be handled by a small helicopter. The AC power is then transformed and rectified at the towed body.
Although the transformer and rectifier components would normally generate excessive and damaging heat at the towed body, the heat is dissipated in the present invention by exposing the transformer and rectifier components at the towed body directly to the sea water. These components are not retained within a watertight enclosure with cooling mechanisms, but are encapsulated within a thin waterproof coating directly exposed to the sea water, the coating protecting the components from the conductive sea water but otherwise cooling the components by passing heat through the thin coating directly to the sea water. Maximum cooling is obtained, and the components can be of significantly reduced size and weight from that which would be required by alternative forms of cooling at the towed body.
The body to be towed also may contain a winch to deploy and return the first electrode. The first electrode also may take alternative forms, such as a cable, a rigid sleeve, or a flexible sock.
Other features and advantages of the present invention will be apparent from the following description, drawings and claims.
REFERENCES:
patent: 2994268 (1961-08-01), Watson
patent: 3060883 (1962-10-01), Herbst et al.
patent: 3940732 (1976-02-01), Hudson et al.
patent: 3946696 (1976-03-01), Lubnow
patent: 4627891 (1986-12-01), Gibbard
patent: 4697522 (1987-10-01), Groschupp et al.
patent: 4938136 (1990-07-01), Gould
patent: 5063850 (1991-11-01), Olsson et al.
patent: 5277117 (1994-01-01), Bender et al.
patent: 5323726 (1994-06-01), Olsson
patent: 5598152 (1997-01-01), Scarzello et al.
patent: 6213021 (2001-04-01), Pickett
EDO Corporation
Jordan Charles T.
Kilgannon & Steidl
Smith Kimberly S
LandOfFree
Open loop minesweeping system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Open loop minesweeping system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Open loop minesweeping system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2527112