Marine anchor
AssigneeBrupat Limited
InventorPeter Bruce
Life of this patent
Estimating the term…
Abstract
A marine anchor has an anhedral fluke with a shank attached thereto including an anchor line attachment point. A rear plate assembly behind the fluke is inclined at an obtuse angle .alpha. to the fluke and serves to provide a turning moment about the attachment point countering turning moments produced by friction effect on the fluke and the shank and by edge resistance during anchor burial to give improved anchor holding power while soil escapes the passage between the rear assembly and the fluke allows escape of sand and soft mud passing over the fluke. Peripheral edges of the rear assembly are shaped to cause rolling of the anchor to a burial position. An upturned toe portion at the front of the fluke encourages effective anchor operation in clay soils while also facilitating rock gripping by the anchor.
Claims51
A marine anchor, symmetrical about a fore-and aft plane, including a basic anchor structure comprising:
- a fluke;
- a shank having a first end and second end, said shank being attached at a fluke angle .theta. to said fluke at said first end and including an anchor line attachment point at said second end;
- a rear assembly including a plate-like surface;
- means for supporting said rear assembly so that said plate-like surface extends aft of said basic anchor structure for reaction with incident mooring-bed soil, said plate-like surface being upwardly inclined relative to said fluke thereby forming a forwardly and upwardly opening obtuse angle of inclination with said fluke;
- and
- soil escape passage means located between said fluke and said rear assembly, said rear assembly being arranged so that said plate-like surface in the anchor burying position presents a substantial forward component of area for substantial arrestment of soil impinging incident on the surface to provide in the plane of symmetry (M--M) a counter turning moment on said anchor about said anchor line attachment point which substantially counters opposing turning moments exerted on said anchor about said point due to pressure and friction of incident non-cohesive mooring bed soil on said shank and fluke during anchor burial in such soil, said soil escape passage means being dimensioned to permit free escape of both granular non-cohesive soils and soft mud cohesive soils passing over the fluke without causing said soft mud cohesive soils to be so retarded as to tend to accumulate over said fluke in advance of said rear assembly.
A marine anchor, symmetrical about a fore-and aft plane, including:
- a fluke having a fluke point;
- a shank having a first end and second end, said shank being attached at a fluke angle .theta. to said fluke at said first end and including an anchor line attachment point at said second end;
- and
- a rear assembly comprising a plate-form structure including a plate-like surface extending aft of said fluke, said plate-like surface in the anchor burying position presenting a substantial forward component of area for substantial arrestment of mooring-bed soil impinging incident on the surface, said plate-like surface being upwardly inclined relative to said fluke thereby forming a forwardly and upwardly opening obtuse angle of inclination with said fluke, the arrangement being such that when said anchor is upside-down in contact with a horizontal mooring bed surface with said plane of symmetry (M--M) vertical with said shank supported only just clear of the mooring bed by an anchor line attached at said attachment point, a point in said rear assembly makes contact with the mooring bed surface to support said anchor in an unstable position thereon, said rear assembly including peripheral edges which are curved to cause rolling of said anchor on:
- said edges under gravity on toppling from said unstable position to bring said fluke into contact with the mooring bed surface.
A marine anchor symmetrical about a fore-and aft plane, comprising:
- a main fluke, said main fluke having a front and an upstanding toe at said front, said toe being upwardly inclined to an adjacent more rearward portion of said main fluke at an obtuse angle .sigma. less than 175.degree. measured in planes parallel to the plane of symmetry, said toe having a bottom edge adapted for penetration of soil;
- a shank having a first end and second end, said shank being attached at said first end to said main fluke so as to be located only at one side of said main fluke and including at said second end an anchor-line attachment point;
- means to orientate said anchor so that said anchor lies tilted on a mooring bed surface with said upstanding toe engaging the mooring bed surface;
- and
- means to support said anchor when in said tilted condition such that said anchor makes contact with the mooring bed surface at three points comprising:
- (A) a foremost end of said shank;
- (B) said toe;
- and
- (C) a point on a rear part of the anchor, whereby said toe can penetrate the mooring bed prior to penetration of the mooring bed by said main fluke.
Dependencies are inferred from the claim text.