US 4,781,142 AGranted

High performance marine anchor

OwnerMaxwell C. Cheunginventor

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Abstract

The present invention is a drag embedment marine anchor having a fluke and shank which are fixed relative to each other during operation. The fluke is symmetrical about its central longitudinal axis and has two pointed front tips for penetrating soil. The elongated shank extends upwardly along the longitudinal axis of the fluke and is rotatably pinned to a trunion at approximately the geometric center of the fluke, to reduce the bending moment in the shank. The attitude of the shank is fixed relative to the fluke at various attitudes by a stopper, to accommodate different soil conditions. The fluke is wedge-shaped in side elevation, and has stabilizer fins protruding upwardly from a stern transom, the stabilizer fins extending beyond the top surface of the fluke to correct yaw. The fluke is formed from a hollow shell having a smooth top surface and a plurality of stiffening ribs depending from its bottom. The ribs create a frictional drag force which facilitates the intitial penetration of the fluke tips into the sea floor. The fluke is preferably fabricated from welded metal plate, cast metal, reinforced concrete or reinforced concrete lined with metal plate.

Claims29

Dependent claims

A drag embedment marine anchor, comprising:

a fluke which is symmetrical about a central longitudinal axis, said fluke having a wedge-shaped exterior when viewed in side elevation and having two pointed front tips for penetrating soil, said fluke having a transom which forms a substantially squared off stern;
a pair of stabilizer fins extending upwardly from said stern transom beyond the top surface of said fluke, said stabilizer fins providing a drag on said fluke as it advances through soil which shifts the pressure center of the fluke behind the geometric center of the fluke, said stabilizer fin also providing a restoring moment on the anchor as it yaws;
an elongated shank extending upwardly from said fluke from a location along said central longitudinal axis, said shank having an arcuate, convex leading edge forming the only curvature between a front end of said shank and a rear end of said shank, the front end of said shank being secured to a mooring chain and the rear end of said shank being secured to the fluke at approximately the geometric center of the fluke so that the bending moment induced in said shank is minimized as the anchor is pulled by the mooring chain through the soil;
and
said fluke is comprised of a hollow shell having a smooth top surface and a plurality of stiffening ribs depending from the bottom of said shell, said ribs being spaced to define voids therebetween which are adapted to be filled with soil as the anchor sinks into the sea floor, said ribs stiffening the shell and also providing a frictional drag force as the anchor is pulled along the sea floor, to aid the initial penetration of the fluke tips into the soil.

2 more elements

Dependencies are inferred from the claim text.