Buoy and Buoy Assembly

This application claims priority to South African Patent Application No. 2024/04505 filed on Jun. 11, 2024, which is hereby incorporated by reference in its entirety.

This disclosure relates to a buoy and to buoy assembly which is useful to create a barrier in a body of water thereby to demarcate a boundary line. In a preferred application the buoy assembly is such as to prevent or deter passage by unauthorised personnel across the boundary line.

U.S. Pat. No. 11,821,157 describes a water barrier formed from buoyant bodies. Additional prior art is disclosed in the citations to that patent.

What the current disclosure seeks to provide is a technique for the construction of a buoy which can be effectively implemented and for the creation of an elongate water barrier from a plurality of the buoys which is resistant to attack and which cannot readily be traversed.

The disclosure provides a buoy comprising a body which is formed from at least two buoyant sections and a fastening arrangement which secures the sections together, and wherein a passage extends through the body.

Each section may be made from buoyant material in any appropriate process e.g. a moulding or roto-moulding process.

The body may have any suitable shape e.g. cylindrical, spherical or the like.

In one embodiment the body has first and second hemispherical ends and between the ends the body is substantially cylindrical in shape. Each buoyant section may then comprise what may be referred to as a half-cylinder with outwardly curved ends.

If the body is spherical and if use is made of two buoyant sections then preferably the sections are identical and each section comprises a hemisphere.

A significant advantage of the hemispherical shape, in each instance, is that there is substantial see-through visibility between ends of adjacent buoys. To prevent, or hinder, unwanted passage between adjacent buoys at least one protruding disc e.g. of circular shape made from metal or a plastics material may be positioned between the buoys. The use of a disc in this way does not unduly interfere with the see-through capability.

A similar benefit can be obtained by replacing the curved ends (hemispherical) in the cylindrical or spherical buoy with tapered ends. This increases the see-through area, but also lowers the deterrent effect between adjacent buoys. Additional discs between the buoys may be called for to address this aspect.

An advantage of shaping the ends of each buoy to be curved or tapered is that water drag, e.g. from flowing water in a river, in which the buoy is deployed, is reduced. The buoy installation is then more stable.

Each section may include an outer surface and an inner surface. The buoyant sections, when secured together by means of the fastening arrangement, preferably have the respective inner surfaces in contact with each other.

Each section on the inner surface may be formed with a respective channel positioned and shaped so that when the sections are secured together the channels form the passage.

The inner surface may include a number of reinforcing members e.g. of discs or other components of a suitable shape which extend transversely to the channel. This feature has been found to promote the formation of flat regular areas on the inner surface and adjacent the channel which, in turn, ensure accurate assembly thereby to facilitate rotation of an assembled buoy around an axial shaft to which the buoy is mounted. This rotation capability comprises an enhanced security feature in that it makes it difficult for an intruder to climb over the buoy.

The passage may have a first end and a second end and, at each end, the passage may terminate in an enlarged mouth which forms a recess in the outer surfaces of the sections.

A shaft may be located in the passage. The body may be rotatable relative to the shaft. The shaft may be rigid or it may be formed from a flexible component such as a specially constructed lightweight cable.

The buoy is free to rotate, without limitation, about the shaft. This is significant for if the buoy were fixed, say, to a chain, the freedom to rotate feature might be impeded.

A first retention or location member may be fixed to the shaft and may be positioned inside the enlarged mouth at one end of the passage. A second similar retention member may be fixed to the shaft, spaced from the first retention member, and may be positioned inside the enlarged mouth at an opposing end of the passage. These members e.g. in form of small discs on the shaft abut opposing surfaces of the buoy inside each enlarged mouth and help to maintain the buoy in an axial sense in position on the shaft but do not inhibit rotation of the buoy on the shaft. The rotation feature is important for it acts significantly to prevent a person from climbing over the buoy which is of a significant size e.g. with a diameter of 500 mm or more-this is exemplary and not limiting.

Each section may be formed with a number of fixing members which are embedded in material from which the section is made. When the inner surfaces of the sections are brought into contact with each other the respective fixing members in the sections are aligned and this provides a means whereby the sections can be secured to each other for example by means of bolts which are engaged with the fixing members.

Alternatively or additionally each section on its outer surface is formed with at least one locating formation with which an elongate fastening strap e.g. in the form of a ring or a part of a ring, is engaged. The locating formation may be a groove and a portion of an elongate strap may be located in the groove. The straps on one section may be fixed to the straps on the other section.

A plurality of straps may be used in this way and the straps may be further secured together by means of members which extend transversely to the longitudinal directions of the straps.

Alternatively and preferably a single strap, basically of circular shape, is located in each respective pair of aligned grooves of two buoy sections. Ends of the strap which carry a locking mechanism e.g. of an over-centre design are coupled to each other and, when actuated, force the two buoyant sections into tight engagement with each other. Once the locking mechanism has been actuated it is fixed e.g. by means of welding, deformation or the use of an adhesive in position so that the locking procedure cannot easily be reversed thereby to allow the two buoy sections to be released from each other—an action which would provide a pathway for unauthorised passage across the shaft to which the buoy sections are mounted.

A buoy assembly may be formed from at least two buoys, each of the aforementioned kind, which are mounted to a common shaft in the manner which has been described. A section of the shaft, between opposing adjacent surfaces of two buoys, may include deterrent structure e.g. in the form of a disc or discs.

The discs may be circular with a diameter approximately equal to the diameter of the buoy.

The deterrent structure may be fixed to the shaft or may be rotatable relative to the shaft.

An anchor component may be provided on the shaft between opposing surfaces of adjacent buoys. The anchor component may be fixed to the shaft or to a disc or may be rotatable relative to the shaft.

A cable or a chain may be fixed to the anchor component thereby to tether the buoy assembly, when it is in water, to an anchor which is on a submerged surface. The number of anchors which are used is variable and is determined taking into account, at least, the strength of water flow at the region where the buoys are used. By way of example in a river installation with a fairly weak current there might be one anchor for twenty buoys. This however is exemplary and non-limiting.

In one embodiment a component which is on the shaft between opposing surfaces of adjacent buoys is used as an attachment point for a net or other structure which, in use, is positioned below the buoys and which is submerged in water with the buoys floating on a surface of the water. This component may be fixed to the shaft or may be rotatable relative to the shaft.

A net, suspended in the water from, and following the line of, a number of interconnected shafts forms an anti-dive barrier below the buoys.

The net may be suspended by means of attachments made to the shaft or to the discs. The former arrangement would be preferred though if the discs are mounted for rotation about the shaft.

A barrier may be formed from a number of buoy assemblies each of which is of the aforementioned kind. An end of a shaft in one barrier assembly is then joined or secured to an abutting end of a shaft of an adjacent barrier assembly. This process is extended to create a barrier of a desired length.

In one embodiment the abutting ends of two adjacent shafts are pivotally movable, to a limited extent, relative to each other. Two important features are present in a barrier constructed in this way. Adjacent barrier assemblies which are connected to each other are nonetheless pivotally movable relative to each other at least to a limited extent. This feature is important because it helps to reduce stresses imposed on the buoys which arise due to movement of water in which the buoys are positioned.

A second important aspect is that it is possible to flank a joint between abutting ends of two adjacent shafts by means of closely spaced deterrent discs or the like. In this way access to the joint is effectively hindered and the security rating of the barrier is markedly enhanced.

In one embodiment ends of adjacent abutting shafts fitted with a clevis and flange arrangement, which allows for a small amount of relative pivotal movement, are joined together for example by using a locking pin which is welded, deformed or adhesively fixed in position to prevent unwanted release. The locking pin is located between two closely spaced discs or the like on the respective shaft to restrict access to the joint.

In the barrier each buoy is rotatable on the shaft to which it is mounted. Each buoy is preferably of a substantial size so that a person in the water trying to cross over the barrier must climb up onto a buoy. As the buoy is rotatable on its shaft this type of passage is difficult.

In one arrangement the outer surface of each section from which a buoy is formed is smooth, except for the aforementioned grooves and fastening straps, so that the outer surface does not readily present a handhold or a foothold to a person attempting to climb over the buoy.

In a different form the outer surface of each section is formed with, or has attached to it, for example by using or modifying the fastening straps, components such as spikes which act as a significant deterrent to a person attempting to climb over a buoy.

of the accompanying drawings is a view from one side of a barrier assemblyaccording to one embodiment. The barrier assembly includes a central shaft() and three buoys,andrespectively.

shows the barrier assembly offrom one side and in cross section but displaced at 90° relative to theillustration.

The shafthas a first endand an opposing second end. A connecting memberin the form of a clevis projects from the first endand a connecting memberin the form of a flange projects from the second end.

The buoys,andare identical to one another. For this reason it is only the construction of the buoywhich is described. The assemblyhas three buoys. This is not limiting as the number of buoys per assembly can be increased or reduced.

Referring tothe buoyis made from two hemispherical sectionswhich are identical to each other. The sections are moulded in a suitable process e.g. using roto-moulding techniques, from a buoyant or cellular material which due to entrapped air has a density less than 1.

Each section has a hemispherical outer surfaceand a flat inner surfacewhich is formed with a centrally positioned diametrically extending channelwhich in cross section is semi-circular. At opposing ends the channel terminates in respective enlarged mouthsandwhich are also semi-circular in shape. When the sections are engaged with each other, the mouths form recesses, on opposed sides of the channels at the junction of the outer surface and the inner surface-see.

Optionally, reinforcing memberse.g. of shaped discs are embedded in the body of each section adjacent the channel. This helps to form flat surfacesA andB between the members, and facing the channel—features which facilitate buoy assembly and ensure that each buoy can rotate freely about its axis, in use.

A baseA of the recess at the mouthis spaced from a baseA of the recess at the mouthby a distance, which is the length of a passageA formed by the two channels.

The outer surfaceof each section is formed with four parallel grooves,,andwhich, viewed from one side, are arcuate.

is a side view of the shaftwhich abuts a similar shaftA.shows a connection jointbetween the shaftsandA on an enlarged scale.

Each shaft,A has a respective number of retention membersA toF, in the form of respective small discs fixed to it.

The spacings between the membersA andB, between the membersC andD, and between the membersE andF, are indicated by the reference numeraland are identical to one another. The dimensionis slightly greater than the dimensionshown in.