GB1584196A

GB1584196A - Anchors

Info

Publication number: GB1584196A
Application number: GB3198077A
Authority: GB
Original assignee: NEW HOOK ANCHORS HOLDING
Current assignee: NEW HOOK ANCHORS HOLDING
Priority date: 1976-08-05
Filing date: 1977-07-29
Publication date: 1981-02-11
Also published as: NL168768B; NL168768C; NL7608728A

Description

(54) IMPROVEMENT S IN OR RELATING TO ANCHORS (71) We, NEW HOOK ANCHORS HOLDING (JERSEY) LilIrrED, of 8 Hill Street, St. Helier, Jersey, Channel Islands, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to an anchor particularly having a rigid fluke construction secured to a two-legged shank.

In such previously proposed anchors each leg of the shank has been secured to a fixed mounting towards the rear of the rigid fluke construction and remote from the forward, fluked end. The rearward connection of the shank with the rigid fluke construction tends to put a heavy load or bending moment on the anchor when it is embedded in ground under high holding forces and the anchor must be made relatively heavy to provide the strength necessary to withstand such stresses.

It is an object of the present invention to provide an anchor in which these stresses may be alleviated or better spread throughout the construction, and there is accordingly provided an anchor comprising a two-legged shank secured to one face of a rigid fluke construction having one or more generally forwardly directed flukes, each of the legs of the shank being secured to said face by a connection on a respective side of the centre of gravity of the rigid fluke construction on a common transversely extending imaginary line which passes through a point lying substantially on said centre of gravity, and the shank having at least two further connections with the rigid fluke construction, each of which is longitudinally spaced from a respective one of the aforementioned connections of the two legs.

Since at least the connections of the shank to the fluke construction on the imaginary line lie more forwardly than has previously been proposed, a load on the fluke construction is more evenly spread than hitherto and the fluke construction can therefore be made relatively lighter or have a larger surface area for the same weight of known anchor. The fluke construction may comprise one wall defining the face to which the two-legged shank is secured, preferably through suitable eyes extending therefrom, and reinforcing ribs may be provided on the face opposed to said firstmentioned face of the wall, particularly but not essentially beneath the portions of the fluke construction to which the shank is connected. Conveniently, however, to further increase the strength of the fluke construction, it is made hollow with upper and lower walls and preferably with reinforcing ribs in between.

The terms "upper" and "upwardly" as used herein are defined by the general direction in which the first-mentioned face projects when the fluke construction lies on a generally horizontal surface and the term "lower" and "downwardly", as well as other corresponding terms, may be construed accordingly.

The legs of the shank may be secured directly at a respective connection to the fluke construction by, for example, securing means in the form of pivot pins or shackles, and the others of the connections joining the shank to the fluke construction may be in the form of chains or tie rods extending to connection points on the shank above the said face of the construction. Said others of the connections may also be secured to the fluke construction by, for example, pivot pins or shackles.

According to one preferred embodiment, the legs are secured directly to the fluke construction on the imaginary line and chains, providing the further connections, extend to connection points on the said face lying both forwardly and rearwardly of the imaginary line.

According to another preferred embodiment, the legs are secured directly to the fluke construction forwardly of the imaginary line and tie rods extend generally downwardly from the shank to meet the said face at connection points lying on the imaginary line.

The anchor of the present invention is preferably provided with ground-engaging stabilizers on the fluke construction which are conveniently arranged laterally of the said centre of gravity substantially on the imaginary line. Such positioning of the stabilizers tends to result in their having more influence than hitherto when the fluke construction is digging into the ground under high holding forces.

In the preferred embodiment the general configuration of the two-legged shank is Vshaped with the apex of the V being upwardly and forwardly of the connections to the rigid fluke construction. Conveniently the shank is in a form in which each shank leg has two ends with one of its ends secured directly to the rigid fluke construction at one of the first-mentioned and further connections, the overall cross-section of each said leg tapering outwardly from its said end to the juncture of the other of the first-mentioned and further connections with the leg (i.e. the point of connection of the leg with, for example, a chain or tie rod).Each leg of the shank conveniently has a lower edge (nearer to the said face of the fluke construction than an upper edge) flared outwardly relative to the upper edge so that the opening defined by the legs and the said face tapers inwardly from the forward, lower edge to permit mud to pass through relatively easily and thereby improve the anchor's ground-penetrating capability. This is in contrast to previously proposed anchors having a two-legged shank, where the shank provides some of'the holding power, but tends to strongly oppose penetration of the anchor into the ground.

Two embodiments of an anchor in accordance with the invention will now be described with reference to the accompanying illustrative drawings, in which: Figure 1 is a schematic plan view of a first embodiment of the anchor, including a twolegged shank and chains being connected from points on the shank to the rigid fluke construction; Figure 2 is a side view of the anchor according to Figure 1; Figure 3 is a schematic plan view of a second embodiment of the anchor, including a two-legged shank and tie rods being connected from points on the shank to the rigid fluke construction;; Figure 4 is a side view of the anchor according to Figure 3, and Figure 5 is a schematic drawing of rigid fluke constructions for anchors of the same weight and in accordance with the invention, the fluke constructions having surface areas which are dependent upon the hardness of the ground in which the anchor is to be used.

Figures 1 and 2 show an anchor generally indicated by the reference numeral 1, and a two-legged shank generally indicated by the reference numeral 2 having legs 3 each of which is secured at a lower end to a rigid, hollow fluke construction 5 provided with two fluke tips at a forward end.

The lower end of each leg 3 is secured to an upper face of the fluke construction by a direct connection in the form of a pivot joint 4 arranged on a respective side of the centre of gravity of the fluke construction, and on an imaginary straight, transverse line passing through a point lying substantially on the centre of gravity. The fluke construction is effectively balanced about this line. Further connections in the form of four chains 6 (shown in chain-dotted lines) extend from connection points on the fluke construction spaced forwardly and rearwardly of the pivot joint 4 to connection points on the shank.

Eyes 7 are provided on the upper face of the fluke construction and on the legs of the shank for the reception of chain shackles, as clearly shown in Figure 2, and each chain is preferably tensioned. The load which is exerted on the fluke construction when the anchor is in use is thus well divided among the pivot joints 4 and the eyes 7 on the fluke construction. As aforementioned the rigid fluke construction is hollow and is defined by upper and lower walls, with the upper wall comprising said upper face. Further, the hollow fluke construction 5 is strengthened by internal reinforcing ribs 10 (shown in dotted lines in Figure 1) which are distributed throughout the construction and particularly beneath the joints 4 and the eyes 7.

Figures 3 and 4 show the second embodiment of the anchor in which a tie rod 8 is arranged between pivot joints 9 on each leg 3 (at a position spaced from each end thereof) and on the upper face of the fluke construction. In this case the pivot joints 9 on the fluke construction are arranged on the imaginary transverse line passing through a point lying on the centre of gravity of the construction, and the lower end of each shank leg 3 is secured directly to the fluke construction forwardly of said line by a pivot joint 4 arranged at about one-third of the fluke length from the forwardmost tip.

The fluke construction is otherwise as described with reference to Figures 1 and 2.

By providing connections for the shank at one-third of the fluke length (as shown in the first embodiment as well as in Figures 3 and 4) the load on the fluke construction is best spread.

Under normal conditions the greatest force will act at the rear connections. When, however, the fluke construction penetrates hard soil under mud or is held fast on rock, the front connections may take the greatest force. Due to the fact that pivot junctions 4 of the shank 2 are more forwardly located than has hitherto been proposed, the fluke construction can be made lighter.

In both embodiments the shank legs 3 are reinforced by ribs 11, and the overall crosssection of each leg, as shown in Figures 2 and 4, tapers outwardly from the pivot joints 4 towards the connection point or points 7 or 9 on the leg with the chains 6 or the tie rod 8.

The two-legged shank 2 in both embodiments is generally V-shaped and in Figures 1 and 2 each leg has a lower edge which is flared more outwardly (i.e. away from the other leg) than an upper edge, so that mud or debris can pass better through the opening which is formed by the legs of the shank and the fluke construction.

In the second embodiment, shown in Figures 3 and 4, the aforesaid advantage isgained by forming each leg with an open framework (viz.

Figure 4).

The vertical cross-section of the hollow fluke construction 5, as shown in Figures 2 and 4, tapers forwardly to a point at the tips of the construction and the upper and lower walls both curve downwardly towards the point (the upper wall curving more than the lower wall to give said tapering effect) to give optimum penetration. The fluke construction is provided with stabilizers 12 arranged laterally of the centre of gravity of the construction and on the imaginary transverse line.

The holding force of the anchor depends to some extent on the ground in which the anchor is embedded. Thus, the requirements for penetration of the fluked construction into hard ground are higher than the requirements when the ground is soft. When an anchor is required to hold fast in soft soil it is possible to bring the stabilizers, which can tend to oppose the penetration, forwardly as shown In Figure 5. In this Figure fluke constructions for anchors of the same weight but for use in various soil types are schematically illustrated.

The fluke construction a has a delta-shape with a single fluke tip. In the larger fluke constructions b or d, in order to keep the overall length of the shank relatively short, the surface area of the fluke construction is enlarged by increasing the width more than the length, and this necessitates the provision of two fluke tips. The anchor b is designed for sand and hard clay and may have a surface area of 54.8m2. The anchors c and d are designed for use in mud/soft ground with a shear strength of 0.8 tlm2 and 0.5 tlm2 respectively and have a surface area of 85.6m2 and 137m2.

Anchors in accordance with the invention may show a considerably larger fluke construction surface area than similar previously proposed anchors of the same weight.

WHAT WE CLAIM IS: 1. An anchor comprising a two-legged shank secured to one face of a rigid fluke construction having one or more generally forwardly directed flukes, each of the legs of the shank being secured to said face by a connection on a respective side of the centre of gravity of the rigid fluke construction on a common transversely extending imaginary line which passes through a point lying substantially on said centre of gravity, and the shank having at least two further connections with the rigid fluke construction, each of which is longitudinally spaced from a respective one of the aforementioned connections of the two legs.

2. An anchor as claimed in claim 1 in which the rigid fluke construction is hollow and comprises upper.and lower walls, the upper wall defining the face to which the two-legged shank is connected.

3. An anchor as claimed in claim 1 or claim 2 in which the rigid fluke construction is provided with reinforcing ribs.

4. An anchor as claimed in claim 3 when dependent on claim 2 in which the ribs are located within the hollow structure of the rigid fluke construction.

5. An anchor as claimed in either of claims 3 and 4 in which those portions of the rigid fluke construction to which the two-legged shank is connected are provided with the reinforcing ribs.

6. An anchor as claimed in any one of the preceding claims in which either the firstmentioned connections or the further connections secure the shank directly to the rigid fluke construction and the others of said connections join the shank to the rigid fluke construction by means of tie rods.

7. An anchor as claimed in any one of claims 1 to 5 in which either the firstmentioned connections or the further connections secure the shank directly to the rigid fluke construction and the others of said connections join the shank to the rigid fluke construction by means of chains.

8. An anchor as claimed in claim 7 in which the direct connections of the shank with the rigid fluke construction are on said imaginary line and the chain connections are provided forwardly and rearwardly of said direct connections.

9. An anchor as claimed in any one of the preceding claims in which eyes are provided at each connection on the said face of the rigid fluke construction through each of which securing means is passed to provide said connections.

10. An anchor as claimed in any one of the preceding claims in which the rigid fluke construction is provided with ground-engaging stabilizers.

11. An anchor as claimed in claim 10 in which the ground-engaging stabilizers are located substantially on said imaginary line on respective side edges of the rigid fluke construction.

12. An anchor as claimed in any one of the preceding claims in which each shank leg has two ends with one of its ends secured directly to the rigid fluke construction at one of the first-mentioned and further connections, the overall cross-section of each said leg tapering outwardly from its said end to the juncture of the other of the first-mentioned and further connections with the leg.

13. An anchor as claimed in any one of

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. on the leg with the chains 6 or the tie rod 8. The two-legged shank 2 in both embodiments is generally V-shaped and in Figures 1 and 2 each leg has a lower edge which is flared more outwardly (i.e. away from the other leg) than an upper edge, so that mud or debris can pass better through the opening which is formed by the legs of the shank and the fluke construction. In the second embodiment, shown in Figures 3 and 4, the aforesaid advantage isgained by forming each leg with an open framework (viz. Figure 4). The vertical cross-section of the hollow fluke construction 5, as shown in Figures 2 and 4, tapers forwardly to a point at the tips of the construction and the upper and lower walls both curve downwardly towards the point (the upper wall curving more than the lower wall to give said tapering effect) to give optimum penetration. The fluke construction is provided with stabilizers 12 arranged laterally of the centre of gravity of the construction and on the imaginary transverse line. The holding force of the anchor depends to some extent on the ground in which the anchor is embedded. Thus, the requirements for penetration of the fluked construction into hard ground are higher than the requirements when the ground is soft. When an anchor is required to hold fast in soft soil it is possible to bring the stabilizers, which can tend to oppose the penetration, forwardly as shown In Figure 5. In this Figure fluke constructions for anchors of the same weight but for use in various soil types are schematically illustrated. The fluke construction a has a delta-shape with a single fluke tip. In the larger fluke constructions b or d, in order to keep the overall length of the shank relatively short, the surface area of the fluke construction is enlarged by increasing the width more than the length, and this necessitates the provision of two fluke tips. The anchor b is designed for sand and hard clay and may have a surface area of 54.8m2. The anchors c and d are designed for use in mud/soft ground with a shear strength of 0.8 tlm2 and 0.5 tlm2 respectively and have a surface area of 85.6m2 and 137m2. Anchors in accordance with the invention may show a considerably larger fluke construction surface area than similar previously proposed anchors of the same weight. WHAT WE CLAIM IS:

1. An anchor comprising a two-legged shank secured to one face of a rigid fluke construction having one or more generally forwardly directed flukes, each of the legs of the shank being secured to said face by a connection on a respective side of the centre of gravity of the rigid fluke construction on a common transversely extending imaginary line which passes through a point lying substantially on said centre of gravity, and the shank having at least two further connections with the rigid fluke construction, each of which is longitudinally spaced from a respective one of the aforementioned connections of the two legs.

13. An anchor as claimed in any one of

the preceding claims in which each of the shank legs is reinforced by ribs.

14. An anchor as claimed in any one of the preceding claims in which each leg of the shank has a lower edge (nearer the said face of the rigid fluke construction than an upper edge) which is flared outwardly (away from the other leg) relative to the upper edge.

15. An anchor substantially as herein described and with reference to Figures 1 and 2 of the accompanying drawings.

16. An anchor substantially as herein described and with reference to Figures 3 and 4 of the accompanying drawings.

17. An anchor as claimed in claim 1 and substantially as herein described with reference to Figure 5 of the accompanying drawings.