US3009174A - Buoys - Google Patents

Description

Nov. 21, 1961 P. D. DAVIES 3,009,174

BUOYS Filed Sept. 23, 1959 2 Sheets-Sheet 1 N V- 21, 19 P. D. DAVIES 3,009,174

BUOYS Filed Sept. 23, 1959 2 Sheets-Sheet 2 X n X C FIGS 3,009,174 BUOYS Patrick Dessiou Davies, The Chatlet, Finchfield Gardens, Wolverhampton, Staifordshire, London, England Filed Sept. 23, 1959, Ser. No. 841,817 Claims priority, application Great Britain Oct. 7, 1958 6 Claims. (Cl. 9-8) This invention concerns improvements relating to buoys, particularly small lighted buoys or floating marks, hereinafter termed buoys, for use as navigation aids at sea and in navigable waterways. These should present a readily visible and clearly distinguishable light at night and a recognisable shape and colour by day. At the same time, such buoys should be of light weight and easy to handle on the one hand and as little aifected by sea conditions as possible on the other hand.

Lightweight reinforced plastic materials offer opportunities for substantial reduction of the weight of a buoy. The resultant reduction in the water-displacing volume of the buoy can, however, lead to undesirable liveliness due to wave motion, currents or wind gusts. Heretofore, steadiness and stability have depended mainly upon underwater weight distribution, especially of ballast, intended to maintain the buoy as closely as possible to the vertical position under all normal seal conditions and thus to ensure recognition of the lightand shape.

Accordingto the invention, a buoy comprises a double conical normally submerged portion consisting of an open bottomed conical skirt or bell surmounted by a flotation body part of inverted conical shape, mooning means being provided approximately at the apices or truncated apices of the cones.

With such a buoy, desirable stability characteristics can be obtained with a minimum of ballast, low weight and convenient shape for handling. Advantageous use can be made of lightweight material such as polyester resin with glass-fibre reinforcement, although metal can naturally be employed.

The conical shapes have a pronounced damping effect on the rocking motion which would be imparted to the buoy by wave motion, especially to a lightweight buo as the conical surfaces are substantially normal to the arc of their oscillation through the water. Any tendency of the buoy to plunge or oscillate vertically due to wave motion is also damped by reason of the battle effect of the said surfaces.

In order to enable the invention to be readily understood reference Will be made to the accompanying drawing illustrating one practical construction by way of example, in which drawing:

FIGURE 1 is a side elevation of an improved buoy the approximate extent of immersion of the buoywhen unmoored being indicated by a water line. I

FIGURE 2 is a plan of the buoy seen in FIGURE 1 but with a dome part and beacon removed, and

FIGURE 3 is a vertical section to a larger scale taken on the line II IIII in FIGURE 2 but showing the dome part in position.

Referring to FIGURE 1, the buoy comprises a base in the form of an open-bottomed skirt or bell a of truncated conical shape, to the bottom rim of which is attached a galvanized steel or other relatively heavy ballast ring b. If desired, a series of ring segments may be used instead of a one-piece ring. The truncated apex of the conical bell a is attached, in a manner hereinafter described, to the truncated apex of a similar but inverted hollow cone which constitutes the lower half of the flotation body of the buoy. The upper half of the flotation body is constituted'by a truncated hollow cone d, the bottom edge of which'is attached to the rim of the inverted cone 0 in a manner to be described. The truncated apex of the hollow cone d is formed to present an upwardly extending neck, hereinafter described, upon which is fitted, in a water-tight manner, a relatively tall dome e surmounted by a lamp f comprising a lens device, such as a dioptric lens, and a cap g. The dome e is held down upon the body part d by four anchoring bolts 0 engaging lugs h on a metal clamping ring h. Alternativelyuse may be made for the purpose of spring hoops which engage over the cap g and have their lower ends anchored to the body part d. Such hoops may be made of robust wire with resilient loops at intermediate points in their the curvature might form part of a truncated parabola. Referring now to FIGURE 3, a galvanized steel eye 1' a mooring cable or chain is attached to the underside and at the centre of the bell a, a backing plate In being secured over the truncated apex of the bell or skirt a where it is attached by means of bolts and nuts to the truncated apex of the lower part c of the flotation body."

Inside the body, this plate In may serve to support lightoperating mechanism, such as a pulse unit for a winker beacon, and a battery. The plate m may also assist in the attachment of the bell a to the body part c in the manner illustrated. The upper part d of the body may or may not be of the truncated conical shape illustrated, the water level x--x being approximately at the lower limit of a short cylindrical band n connecting the bases of the cones c and d. There are no mooring means at Water level.

The upper part d of the body is formed with a deep neck d adapted for receiving the lower part of the dome e with a watertight fit. Around the base of the neck a" the body part d is formed with four hollow lugs n spaced apart and adapted for the bonding in of the anchoring bolts 0 for the ring it. The backing plate m may be of the cup formation shown, the wall m of the cup being adapted for tightly seating a tubular part q of square section adapted for receiving a battery and electrical accessories. A flanged cylindrical metal insert q in the base part of the neck d extends with its flange over a thickened top rim p of the tubular part p, the latter being secured in place by screw-threaded rods r which are anchored at their lower ends to the cup m m and pass with their upper screw-threaded ends through the rim p and flange of the inset q there to receive fixing nuts as shown. The dome e is, of course, removable so as to give access to the battery and electrical accessories. In FIGURE 3, various bondings, jointings and reinforcements for a synthetic resin construction are indicated, but these need not be described in detail as they constitute no part of the present invention. However, it may be mentioned that whereas the band n, which may be of metal, is applied externally of the joint between the body parts 0 and d, internally the joint is made good and the parts are reinforced by a deep band n of bonding material. Within the dome e there may be secured, by appropriate bonding, screw or other devices s for the attachment of electrical accessories or of devices suitable for supporting electric leads or the like.

With the construction of lightweight buoy illustrated, the underwater components a and 0 give the desired stability characteristics with a minimum of ballasting. Where wave motion of the water would normally cause rocking to and fro of a lightweight buoy, the conical bell a has Patented Nev.- 21, 1 961 The a pronounced damping efiect on such motion due to the submerged conical surfaces being substantially normal to the arc of oscillation of the conical surfaces through the water having regard to the point of mooring l of the buoy. Any tendency of the buoy to plunge or to acquire vertical oscillation is reduced by virtue of the battle effect exerted by the submerged conical surfaces. When the buoy is floating in a current or tidal stream, the motion of the water is substantially horizontal and tends to carry the buoy with it, but it is kept in position by the mooring cable the restraint of which is applied at the eye I. The latter therefore constitutes a pivot point for the buoy and unless this point is approximately in the same horizontal plane as the centre of horizontal pressure exerted by the current in the submerged area, the buoy will tilt either away from or towards the current depending upon whether the said point is above or below the said centre. The mooring eye I being disposed as hereinbefore described is most advantageously situated for restraining the buoy with stability for the latter. Moreover, the junction between the two truncated apices of the conical parts a and c for the attachment of the eye I is the ideal point of attachment from the mechanical point of view when considering the strength of the structure for the resistance of the restraining forces. Finally, since the weight of the buoy acts through the centre of gravity, the attachment of the eye I in the position described en ables the restraining force to be applied as closely as possible to the centre of gravity.

The distribution of the light, as in the common marine lantern beam, will generally be such that most of the light is emitted in a horizontal plane, in which it is observed.

7'. This will ensure a long luminous range with a small power of light source, with consequent economy in operation.

I claim:

1. A buoy comprising a hollow flotation body the lower and normally submerged portion of which is of inverted substantially conical shape, an open bottomed, substantially conical skirt concentrically positioned with its apex abutting the apex of the lower portion of said flotation body, connecting means nigidly securing the abutting apices one to the other, and mooring means attached to the apex of said skirt.

2. A buoy as claimed in claim 1, which said lower and normally submerged portion of the flotation body and said skirt are formed as similar truncated cones.

3. A buoy as claimed in claim 1, wherein the flotation body comprises an upper portion in the form of a conical cover rigidly attached to the inverted conical lower portion, the said cover being fitted with lifting eyes.

4. A buoy as claimed in claim 1, wherein the apex angles of the conical shapes are about 5. A buoy as claimed in claim 1, wherein the conical skirt is of lightweight material and has attached to its bottom edge at least one ring part of heavy material.

6. A buoy as claimed in claim 1, wherein the centre of gravity of the buoy and the point of attachment of the mooring means approximately coincide.

References Cited in the file of this patent UNITED STATES PATENTS 1,530,804 Anundi ..t Mar. 24, 1925 1,811,014 Kerwin June 23, 1931 2,214,453 Creed Sept. 10, 1940

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