US3893201A

US3893201A - Multi-buoyancy buoy

Info

Publication number: US3893201A
Application number: US436568A
Authority: US
Inventors: Ray R Mallory
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1974-01-25
Filing date: 1974-01-25
Publication date: 1975-07-08
Anticipated expiration: 1992-07-08

Abstract

Multi-buoyancy buoys are described wherein a central, basic buoy has a plurality of arcuate flotation elements removably secured thereabout to selectively provide buoyancy and stability in addition to those of the basic buoy.

Description

United States Patent [1 1 [111 3,893,201 Mallory July 8, 1975 MULTI-BUOYANCY BUOY 3,082,439 3/1963 Hornbostel et al. 9/8 F 1694,83? l0/l972 N [75] Inventor: Ray Manmy' Panama CltY 3,803,651 4/l974 9/8 11 [73] Assignee: The United States of America as represented by the Secretary of the Primary ExaminerTrygve M. Blix y. ng n. C Assistant ExaminerStuart M. Goldstein Attorney, Agent, or Firm-Richard S. Sciascia; Don D. 22 Fl Z 74 I I led Jan 5 l9 Doty; Harvey A. David 211 Appl. No.: 436,568

[57] ABSTRACT 52 U.S. Cl 9/8 R 5| 1m. cl. T. B63B 21/52 Mum-bwyancy buoys are descrlbed wherein a [58] Field of Search 9/8 R basic buoy has a Pluralily of flotation ments removably secured thereabout to selectively [56] References cued provide buoyancy and stability in addition to those of UNITED STATES PATENTS has:

2.9l0,834 11/1959 Knapp 9/8 R 2 Claims, 5 Drawing Figures MULTI-BUOYANCY BUOY STATEMENT OF GOVERNMENT INTEREST The invention described herein may be manufactured and used by or for the Government of the United States of America for Governmental purposes without the payment of any royalties thereon or therefor.

FIELD OF THE INVENTION This invention relates to buoys used for marking cations. supporting scientific instruments and other purposes. Buoys that are moored are generally provided with ground tackle that includes mooring line. cable, chain, or the like of sufficient scope to prevent the anchor from being dragged by prevailing water currents acting on the buoy. and also to prevent a buoy of given buoyancy and dimensions from being submerged by such currents. Generally, increasing scope of ground tackle increases its holding power while at the same time reduces likelihood of a buoy being swept under by running currents. There are, of course. practical limits to extension of ground tackle scope. These include the requirements of handling and maintaining inordinate lengths of cable, and the increase in the watch circle or radius of travel of the buoy. representing a reduction in positioned accuracy.

An alternative measure to prevent a buoy of moderate scope from being swept under water by swift currents is to use a buoy of greater buoyancy. Now, in instances of relatively permanent buoys for marking channels, and the like, buoy size selection and mooring scope can be effectively predicated upon experience. and such buoys are not often required to be moved or retrieved. Accordingly. such buoys are selected with substantial amounts of reserve buoyancy and ground tackle holding power.

In the case of temporary buoyage. for example in scientific endeavors, the wide variety of water depths, current conditions, and scientific instrument pay loads which must be met. would require a wide range and variety of buoys and buoy sizes in order to avoid instances of inordinately large mooring line scopev DISCUSSION OF THE PRIOR ART Variable buoyancy buoys have been proposed heretofore, some of which have relied upon addition of one or more buoyancy sections. and others of which have relied upon means increasing the amount of gas in either a flexible or a rigid chamber. US. Pat. No. 2,680,859 to A. A. Hultberg is an example of the added section approach, while US. Pat. No. 3,256,539 to A. P. Clark is an example of a flexible chamber technique. The former is limited to selection of buoyancy by vertical stacking of substantially identical cylindrical float units held together by a rod through the common axis of the stacked units. While this provides for buoyancy selection, the resulting buoy structure tends to lack lateral stability unless ballast. for example in the form of internal concrete. is used. Such ballast. of course. reduces the effective buoyancy. and renders the buoys more difficult to handle.

The flexible chamber technique is relatively complex. and is more suited to specialized applications, where remote control of buoyancy is required. Moreover. in either of the foregoing types of variable buoyancy arrangements it is necessary to construct the entire device. rather than continuing to make use ofcxisting buoys.

BRIEF SUMMARY OF THE INVENTION The present invention aims to overcome most or all of the foregoing shortcomings and disadvantages of the prior art through the provision. in combination with a basic buoy. of add-on flotation means for increasing the buoyancy of the basic buoy and, if desired. the stability thereof.

With the foregoing in mind. it is a principal object of this invention to provide an improved buoy apparatus which will eliminate the high costs and inconvenience of providing a number of conventional buoys in a plurality of sizes.

Another important object of the invention is the provision of a buoy assembly comprising a basic buoy and a plurality of arcuate flotation elements fixed about said basic buoy so as to increase buoyancy and stability thereof, the arcuate flotation elements being removable for use of the basic buoy alone. or for replacement by other arcuate flotation elements. whereby a composite buoy having the most desirable degree of buoyancy for a particular water depth. current. and mooring scope can be assembled in a short time.

Still another object is the provision of a multiple buoyancy buoy apparatus of the foregoing character. wherein the flotation elements are formed principally of a rigid plastic foam, such as expanded polystyrene. covered by a durable skin of a compatible plastic resin. preferably incorporating a suitable reinforcing material such as glass fiber.

Other objects and many of the attendant advantages will be readily appreciated as the subject invention becomes better understood by reference to the following detailed description, when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of a multiple buoyancy buoy embodying the invention;

FIG. 2 is a sectional view of the buoy of FIG. 1, taken substantially along line 22 thereof;

FIG. 3 is a diagrammatic illustration depicting operation of the buoy of FIG. 1;

FIG. 4 is a plan view of another embodiment of the invention; and

FIG. 5 is a side view, partly in elevation and partly in section. of the embodiment of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the form of the invention illustrated in FIGS. 1 and 2, a multi-buoyancy buoy. generally indicated at I0, comprises a basic buoy l4 and a buoyancy increasing flotation assembly 16 mounted on basic buoy 14 in encircling relation thereto. Basic buoy I4, in this exemplary embodiment, comprises a circular hull Ma. as viewed in plan. from which depends an annular keel 14]). Hull 14a is characterized by a substantially flat top deck 14c. a substantially flat bottom surface 14d. and a side wall He presenting a substantial dcadrise or flare.

Depending from the bottom surface 14d, on diametrically opposite sides of keel 14b, are a pair of apertured flanges or eyes 18 that serve as pivotal connections for a bail 20. Bail 20 serves as a connection means for mooring gear or ground tackle, such as includes a cable 22 secured to the bail by a shackle 24. Cable 22 may be secured to any suitable form of anchor for the circumstances in which buoy is to be moored, and cable 22 may have a scope commensurate therewith as will later be discussed with reference to FIG. 3. Basic buoy 14 may further be provided with any other fitment to suit it for scientific or other purposes, a central vertical antenna mast 26 being illustrated as representative thereof.

The buoyancy increasing flotation assembly 16 comprises a plurality, four in this example. of arcuate flotation elements 28 joined together in a circle in embrac' ing relation to basic buoy 14. Each arcuate flotation element 2 is conveniently formed of a tough, durable. skin or shell 30, preferably molded of a material such as fiberglass reinforced polyester resin, and a cellular, rigid plastic foam core 32, preferably comprising expanded polystyrene or polyurethane material. The inner arcuate surface of each flotation element 28 is desirably molded or shaped so as to be complementary to the shape of the side wall l4e of hull 14 so as to provide a snug fit thereagainst when assembled.

inwardly directed ears or tangs 34 are provided, conveniently as an integrally molded portion of shell 30, with one such tang extending radially from each end of each flotation element 28. Tangs 34, which are disposed in congruent pairs in the assembled buoy 10, are apertured to receive bolts 38, or other suitable fasteners. Because tangs 34 overlie the deck [40 of basic buoy l4, and because of the complementary shaping of surfaces of the flotation elements adjacent thereto, the flotation elements are firmly secured in position on the basic buoy without any specific fixtures being necessary on the latter.

MODE OF OPERATION Referring to FIG. 3, consider a basic buoy 14 to be moored in water W by means of ground tackle including cable 22 and a suitable anchor A on the bottom B. Consider also that, with a scope of say 2:1, and a current running of velocity V, buoy 14 will just float satisfactorily to perform its position indicating, scientific data transmitting, or other design function. In this condition basic buoy 14 has a watch circle radius of R. Now, if the current increases in velocity to V, basic buoy [4 will no longer have adequate buoyancy, with a cable scope of 2:1 to perform its intended function. Rather, it will be swept underwater to some position such as that indicated in dotted lines. This circumstance has generally been met in the past simply by increasing the cable scope as shown in FIG. 3 by basic buoy l4 and cable 22'. The result is a greatly increased watch circle radius R, often unacceptable in terms of scientific accuracy.

In accordance with the present invention, however, the watch circle radius R can be retained in spite of the greater current V, by retaining the cable 22 of lesser scope and adding flotation assembly 16 elements 28 to basic buoy 14 to arrive at multiple buoyancy buoy l0. Buoy 10 will, as shown in FIG. 3, provide the desired smaller watch circle radius R with the shorter cable 22, even at current V. By having a number of flotataion assemblies 16 of different displacements, it is possible to meet a wide range of buoyancy requirements with a single basic buoy 14.

It will be recognized that the flotation elements 28 not only increase the buoyancy of buoy H], but also we tend the beam thereof in such a manner as to render buoy l0 considerably more stable than basic buoy 14.

Referring now to FIGS. 4 and 5, another embodiment of multi-buoyancy buoy is indicated generally at 40, this embodiment being preferred for lighter duty than that previously described. Buoy 40 comprises a cylin drical basic buoy 42 in combination with an assembly of arcuate flotation elements. Basic buoy 42 is provided with a suitable mast 44 extending axially through the cylindrical body thereof, which body may conveniently be formed of a suitable expanded plastic resin material, such as polystyrene. A mooring eye 44a is formed at the lower end of mast 44, below the cylindrical body.

The arcuate flotation elements comprise a pair of semicylindrical elements 460 and 46h snugly encompassing the body of basic buoy 42. Elements 46a and 46b are also conveniently formed of an expanded plastic foam material such as polystyrene. and each is substantially of the same height as the basic buoy body. Another pair of arcuate, semi-cylindrical flotation elements 48a and 48b are disposed in snug encompassing relation to the lower half or so of flotation elements 460 and 46b. A band 50 of plastic or corrosion resistant metal surrounds flotation elements 48a, 48b and binds those elements, as well as elements 46a, 46b to the basic buoy body.

Vertically stacked on elements 48a, 48b are a substantially identical pair of arcuate. semi-cylindrical flotation elements 52a and 52b, in snugly encompassing relation to the upper half or so of flotation elements 46a. 46b. Another band 50 binds elements 52a, 52b, elements 46a, 46b, and the basic buoy together.

Buoy 40 comprises, therefore, in addition to basic buoy 42, a number of flotation elements which increase the buoyancy above that of the basic buoy alone. It will be recognized that one or more of the pairs of flotation elements may be omitted from the combination. desired to provide a buoy 40 having the degree of buoyancy desired.

Obviously, other embodiments and modifications of the subject invention will readily come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing description and the drawings. It is, therefore, to be understood that this invention is not to be limited thereto and that said modifications and embodiments are intended to be included within the scope of the appended claims.

What is claimed is:

l. A multiple bouyancy bouy comprising in combination:

a basic bouy for providing a first predetermined amount of positive bouyancy, said basic bouy comprising a hull that is circular in plan, has a substantially flat bottom surface of a first diameter, a substantially flat deck surface of a second diameter that is larger than said first diameter, and an annular side wall presenting a curved. sloping outer surface extending upwardly and outwardly from the periphery of said bottom surface to the periphery of said deck;

a plurality of arcuate flotation elements assembled in the form of a ring and embracing said basic bouy so as to provide additional bouyancy, each of said elements comprising only a segmental section of said ring and presenting a curved and sloping inner tion to a tang of another of said flotation elements and said tangs being free of direct connection to said bouy; and

releasable fastener means securing together mutually adjacent ones of said tangs.

2. A multiple bouyancy bouy as defined in claim I,

and wherein:

said ring comprises four of said arcuate flotation elements. and each segmental section extends substantially one quarter of a circle.

Claims

1. A multiple bouyancy bouy comprising in combination: a basic bouy for providing a first predetermined amount of positive bouyancy, said basic bouy comprising a hull that is circular in plan, has a substantially flat bottom surface of a first diameter, a substantially flat deck surface of a second diameter that is larger than said first diameter, and an annular side wall presenting a curved, sloping outer surface extending upwardly and outwardly from the periphery of said bottom surface to the periphery of said deck; a plurality of arcuate flotation elements assembled in the form of a ring and embracing said basic bouy so as to provide additional bouyancy, each of said elements comprising only a segmental section of said ring and presenting a curved and sloping inner surface complimentary to and adjacent a corresponding portion of said sloping outer surface of said side wall, whereby upward movement of said ring relative to said basic bouy is precluded by cooperation between said outer and inner surfaces; each of said flotation elements further comprising a plurality of tangs each extending radially inwardly from one end thereof in overlying relation to said deck, whereby said ring is prevented from downward movement relative to said basic bouy, each of said tangs being disposed in mutually adjacent relation to a tang of another of said flotation elements and said tangs being free of direct connection to said bouy; and releasable fastener means securing together mutually adjacent ones of said tangs.

2. A multiple bouyancy bouy as defined in claim 1, and wherein: said ring comprises four of said arcuate flotation elements, and each segmental section extends substantially one quarter of a circle.