Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1999-03-03
2001-03-06
Knable, Geoffrey L. (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C114S222000, C156S212000, C405S216000, C428S907000
Reexamination Certificate
active
06197137
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of preventing adhesion of aquatic organisms on structures in water, such as ships, and more particularly, to a method of preventing adhesion of aquatic organisms on underwater structures such as ships with easy operation, without landing of the structures and at a low cost.
2. Description of Prior Art
In the sea are floating larvae, spawn and seeds of aquatic organisms such as barnacles, shellfish, sea weeds and algae. These living things may adhere to underwater parts of moored ships such as fishing boats or leisure boats, and begin to grow up at these parts. The mooring for a long term causes shellfish to grow up in a large lump, which may damage the ship if left to stand as they are, thus considerably reducing the life of the ship. Furthermore, when ships navigate with aquatic organisms adhered to the underwater parts thereof, increased water resistance to the navigation may increase fuel cost and rolling of ships may hardly secure safe navigation.
It is actually impossible to mechanically scrape the bottom of ships in the water to remove the adhered aquatic organisms therefrom. Normally, the ships have to be landed for the scraping. This case necessitates lifting means such as a crane and a board space, so that the cost is increased and a great amount of manpower is required.
Thus, a method of preventing adhesion of aquatic organisms on ships has been required and many methods have been developed.
There is a method using a special paint for preventing the adhesion. This method requires ship landing for applying the paint to the bottom of ship, and furthermore, the paint duration is short. Also, use of such special paints has been objected in view of protection of environments, because some of the paints may include ingredients harmful to shellfish or human bodies.
JP Unexamined Patent Publication No. 7-96891 discloses one method of preventing adhesion of aquatic organisms on a ship without requiring landing of the ship. According to the method, the ship is wrapped at the underwater part thereof with a waterproof sheet, thereby reducing the salt content in sea water between the ship and the sheet to kill the spawn of shellfish. Another method was proposed in JP Unexamined Patent Publication No. 60-94892. In this method, the whole of a ship is covered with a light-untransmitting sheet, thereby inhibiting aquatic organisms from growing up on the ship. A still further method was proposed in JP Unexamined Patent Publication No. 4-50598. In this method, an air bag is slipped under the ship bottom, and the bag is inflated with air, so that it may be brought into close contact with the ship bottom. Thus, aquatic organisms are prevented from adhering to the ship bottom. These proposed methods are, however, not satisfactory, because they have some defects or inconvenience. In particular, they require a member having a unique shape made by stitching up or welding elements, and the operation of the member is hard due to its complicated shape when the member is set on the ship bottom. Furthermore, these methods require a great amount of labor cost.
Moreover, JP Unexamined Patent Publication No. 63-22908 discloses a method of preventing aquatic organisms from adhering to ship bottoms, in which underwater structures are covered with a cloth, net or porous sheet of 1 mm or more thick and having a space through which water can easily be replaced (see the claims). According to this publication, this sheet can hardly prevent aquatic organisms from the adhesion, if it has a thickness of less than 1 (see page 3, right-hand lower column, line 3 to page 4, left-hand upper column, line 2 of the publication). In fact, a great amount of aquatic organisms were adhered when the cloth sheet had a thickness of 0.5 mm in the Comparative Example.
Furthermore, this publication describes that the porous sheet may be made of, for example, a foamed polyurethane, foamed polystyrene, foamed polyethylene, etc., and these foams have a standard pore number of preferably 5 to 20 per 25 mm (see page 3, right-hand lower column, lines 12 to 17). Referring to the working examples of this publication, Example 1 used a polyurethane foam sheet of 10 mm thick as the porous sheet, Example 7 used a net made of polyethylene, and Example 8 used a porous reticulated structure made of synthetic fibers.
Thus, the porous sheet of the publication above is very thick. This should be called a plate rather than a sheet. Underwater structures of a large scale can very hardly be covered with such a plate-like sheet.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide a method of preventing adhesion of aquatic organisms on structures such as ships without necessity of landing the structures, which overcomes the defect or inconvenience of the prior art and can easily be operated at a low cost.
REFERENCES:
patent: 3685477 (1972-08-01), Wood
patent: 4098955 (1978-07-01), Partridge
patent: 5226380 (1993-07-01), Fischer
patent: 59-134208 (1984-08-01), None
patent: 63-22908 (1988-01-01), None
Akahani Kaoru
Kikuchi Masahiro
Akahani Kaoru
Arent Fox Kintner Plotkin & Kahn
Knable Geoffrey L.
LandOfFree
Method of preventing adhesion of aquatic organisms in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of preventing adhesion of aquatic organisms in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of preventing adhesion of aquatic organisms in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497157