US3022762A

US3022762A - Anchor

Info

Publication number: US3022762A
Application number: US859261A
Authority: US
Inventors: Carrol W Hillcourt
Original assignee: Individual
Current assignee: Individual
Priority date: 1959-12-14
Filing date: 1959-12-14
Publication date: 1962-02-27
Anticipated expiration: 1979-02-27

Description

Feb. 27, 1962 c. w. HILLCOURT ANCHOR Filed Dec. 14, 1959 INVENTOR CARROL W. H/LLCOURT ATTORNEYS 3,022,762 ANCHOR Carroi W. Hillcourt, 342 Liberty St., San Francisco, Calif. Filed Dec. 14, 1959, Ser. No. 859,261 9 Claims. (Cl. 114-2il8) This invention relates to an anchor for boats, and more particularly to an anchor having a fluke pivotally carried on a shank for burrowing into the sand or mud at the sea floor and wedge therein against displacement. This application is a continuation-in-part of my copending application Serial No. 773,236 filed November 12, 1958, now abandoned.

It is an object of this invention to provide an anchor combining the advantages of minimum weight with maximum holding power.

It is a further object of this invention to provide an anchor having a pivoted fluke capable of expeditious penetration into the sea floor while presenting a maximum vertical area of resistance against displacement.

It is a further object of this invention to provide an anchor that burrows easily into the sea floor and holds rigidly against displacement but which may be easily removed and raised when it is desired to do so.

it is a further object of this invention to provide an anchor that is' simple in construction and reliable in operation.

An anchor constructed in accordance with this invention includes an elongate shank to one end of which is secured the anchor line. At the other end of the shank is pivotally mounted a fluke having a burrowing tip and a relatively wide base from which there extends a pair of rearwardly diverging tail plates forming a wedge at the trailing end of the fluke. The fluke is pivotable on the shank about an axis rearward of the apex of the tail plate wedge so that a maximum portion of the tail plate surface will be pivoted below the level of the shank which is supported on the sea floor. Stop means limit the pivotal movement of the fluke to a relatively small angle so that the fluke penetrates rather easily into the substance of the sea floor under the generally horizontal forces that are extended along the anchor line by surface forces tending to move the boat. Once resistance to penetration is overcome a steeper Wedging angle is introduced to burrow deeper and to present a more nearly vertical surface in engagement with the sand or mud of the sea floor in opposition to displacement by the horizontal force. Because the displacing force is in a generally horizontal direction the capacity of the fluke to resist displacement is proportionate to the vertical projected area of the fluke. Hence, the near vertical disposition of the tail plate wedge affords near maximum holding capacity per area thereof. The fluke is pivoted about an axis displaced rearwardly of the wedge so that a maximum area of the tail plate wedge will pivot below the shank to penetrate into the sea door. The stop means for limiting pivotal movement of the fluke are also arranged as far to the rearward end of the shank as is possible in order to achieve maximum mechanical advantage for removal of the anchor. That is, with the connection between the shank and the fluke, i.e. the stop means, near one end of the shank and the connection to the anchor line at the other end of the shank the resultant long lever arm facilitates removal under upward pull to pivot the fluke with the shank free of the mud.

Other objects and advantages of my invention will become apparent from the specification following when read in connection with the accompanying drawings wherein:

FIG. 1 is an isometric view of a preferred form of anchor embodying features of my invention;

1 FIG. 2 is a vertical section view of the anchor of FIG.

; and

FIG. 3 is an isometric view of an alternate form of anchor embodying features of my invention.

Referring now to the drawings in greater detail, the preferred form of anchor 1 has ashank 2 having a hole 3 in one end thereof to carry a shackle 4 for attachment of the anchor to an anchor line 5 secured to the buoyant craft afloat at the surface.

Preferably, the shank 2 is of yoke configuration having branched arms 6 between the extremities of Whichis fixed a rod or shaft '7. A second rod 8 spans the spaced arms 6, being secured rigidly thereto forward of the shaft 7, and thus contributes to the rigidity of the shank 2.

The fluke 10 is made up of a rigid plate 11, preferably of generally triangular configuration having a pointed tip 12 forburrowing into the sand or mud of the sea floor. Secured to and diverging rearwardly from opposite sides of the face of the triangular plate 11 are a pair of tail plates 14 which together form a wedge having its apex 15 along the base of the fluke plate 11. Strengthening ribs 16 may be welded or otherwise rigidly se-' cured to the fluke plate. lland to the diverging tail plates 14 to rigidify the structure.

The composite fluke 10 is pivotally mounted on the shank 2 about the shaft 7 and is disposed relative thereto so that the shaft 7 lies in the plane of the fluke plate 11 and is parallel to and spaced rearwardly from the apex 15 of the composite wedge formed bythe tail plates 14. In the preferred embodiment shown in FIGS. 1 and 2 the shaft 7 is located in such position relative to the fluke plate 11 and tail plates 14, by rigidly securing to the diverging tail plates 14 a pair of rearwardly extending bearing brackets 24) which rotatably receive the shaft 7. For simplicity of construction, the brackets may simply be cast with aligned holes 21 formed therein rotatably to receive the shaft 7 secured between the arms 6 of the shank 2. The brackets 20 also include arcuate openings 22 which terminate in stop. surfaces 23, to receive the rod 8 so that engagement of the rod 8 with the stop surfaces defines the limit of pivotal movement of the fluke 10 about the shaft 7.

In actual use, the anchor 1 is pulled by a force F on the anchor line along a generally horizontal line with the anchor shank 2 being supported by the sea floor in v a generally horizontal disposition. Thus, the angle a that the fluke plate 11 makes with the axis 25 of the shank 2 determines the angle of entrance of the fluke plate 11 into the sea floor. I have found that the rod 8 and stop surfaces 23 of thebearing frame should be arranged so that the angle ofentrance of the fluke-should be in the range from 25 to 55 and preferably about 35. An angle of entry of about 35 is small enough that the generally horizontal force F has a substantial component along the plane of the fluke plate 11. Moreover, at approximately 35 the mechanical advantage is high thereby to facilitate penetration. At the same time, the inclination of the fluke plate 11 is steep enough to direct penetration downward and to present a substantial efiective vertical surface, as indicated in phantom projection V 1a, against which the horizontal displacement resisting forces 1 act.

Similarly, the angle 0 at which each tail plate 14 is disposed relative to the plane of the fluke plate 11 should also be in the range from 25 to 55, and preferably about 35. With each wedge-like tail plate 14 diverging at an angle of 35 the upper tail plate assumes a 70 angle of entry into the sea floor while the fluke plate is pivoted to 35 from the shank axis 25 which corresponds generally to the level of the sea floor. Once the inertia of resistance to penetration is overcome and the fluke is burrowing into the sea floormud the steep upper diverging wedgeplate l4 delivers a final downward wedging thrust firmly to anchor the fluke into the sand. At the same time the broad wedge-like configuration of the diverging tail plates tends to limit the penetration of the anchor and prevent it from going too deep into the sea floor. As pointed out, the holding power'is dependent upon a vertical projection of the area and burying the anchor too deeply merely hinders its'removal under vertical force. The increased slope of the upper wedging tail plate produces a vertical projected area 14a of almost full size to achieve maximum anchoring force distributed thereover and represented by the arrows f. The effectof the steep angle of the upper wedge is particularly significant in the case of the tail plates 14 since they are of full width and hence, of maximum area per unit depth of penetration.

With the pivotal axis 7 spaced rearwardly from the apex 15 of the composite wedge formed by the tail plates 14, virtually all of the area of upper tail plate 14 will be pivoted below the level of the shank and hence driven into the sea floor upon which the shank 2 is supported. Hence, maximum displacement resisting area is activated by penetration into the sea floor. Moreover, since virtually all of the tail plate surface 14 is below the level ofthe pivot shaft 7, no opposing moment arm is presented which would otherwise tend to pivot the fluke 10 up- :ardly under the mud forces f and thereby reduce the wedges should be large enough to achieve maximum projected area 14a, but small enough to achieve the downward driving force to complete the anchoring action. In this connection, it is obvious that it is desirable to have the entry angle of the wedge 15 relative to the direction of force F less than 90 because when the angle exceeds 90 there will be a resultant resistance to forward movement and no tendency to drive the fluke 10 downward in response thereto.

While experiments indicate that optimum performance can be realized with the angle on and 6' set at about 35 it is obvious that the desired purposes can be achieved over a reasonable range of angles. For example, with the angles a and 6 set at 30, the entrance angle of the upper tail plate will be 60 and when they both are at 40, the entrance .angle of the tail plane will be 80". In both instances reasonable wedging action and satisfactory vertical area projection may be realized. It is not to beimplied, however, that the angles or and 0 need be identical; the designer can depart from the preferred angles stated in any way within a reasonable range that 1 enables him to achieve a satisfactory combination of good penetration and suitable holding capacity.

When it is desired to raise the anchor, tension is applied to the anchor line 5 in the usual manner to move the craft to a position above the anchor. With the lifting force F now in a vertical direction, the anchor is pivoted about the rearward end thereof, as for example the rearward edge of the lower tail plate 14. The rod 8 and stop portions 23 of the bearing member function as a oneway clutch to pivot the fluke 10 with the shank 2. Since the engagement of the'elements 8, 23 is closely adjacent to the rearward end of the anchor and the raising force F is at the opposite end, the load of the fiuke is carried by the shank at a very large mechanical advantage. The long lever arm facilitates removal of the anchor under vertical force F If desired removal of the anchor may be further facilitated by providing an opening 26 in the fluke 11 to permit release of any vacuum that may be created between the plate 11 and the mud of the sea floor.

l have found that the yoke type 2 is most satisfactory because it provides maximum strength; because it tends to lie fiat on the sea floor; and because it enables the use of a single, large surfaced fluke therewith. However, it is to be understood that a split fluke could be used in conjunction with a single bar shank according to the rinciples of this invention with satisfactory results.

While it is preferred to have the pivotal axis of the fluke spaced rearward from the apex of the diverging tail plates so as to swing the entire mea of the upper tail plate below the surface of the sea floor, I have achieved satisfactory anchoring by locating the pivotal axis immediately behind the apex 15b as shown in the embodiment of PEG. 3. There, a shaft 7b may be welded directly to the junctureof' the tail plates 14b and thefiuke triangular plate 11!) and rotatably carried between the spaced arms 6 of the shank 2. In this, as in the other embodiment, the stop 8b may operate directly upon the portions on the diverging tail plates 14b to limit the angle of entrance of the fluke plate 11b. Again, a vacuum relieving opening 261') may be provided if desired.

While I have described preferred embodiments of this invention, it is apparent that modifications and changes can be made therein without departing from the spirit and scope of this invention which is defined in the claims appended hereto. f

Having described my invention, I claim:

1. An anchor comprising: an elongate yoke-like shank having diverging arms and connecting means at the closed end thereof for attachment to an anchor line, a fluke having a base and a burrowing tip, rearwardly diverging tail'sections on said fluke forming a Wedge with the apex thereof secured to and extending along said base, journal means mounting said fluke on the other end of said shank between said arms for pivotal movement about an axis generally parallel to and rearward of said apex, and cooperating stop means on said shank and said tail sections to limit the extent of said pivotal movement in opposite directions, said tail sections being disposed at angles relative to said fluke so that when said shank is generally horizontally disposed the angle of the upper one of said tail plates relative to said shank is less than 9i) degrees when said pivotal movement is limited by said stop means.

2. An anchor comprising: an elongate yoke-like shank having diverging arms and connecting means at the closed end thereof for attachment to an anchor line, a fluke having a relatively wide base and a burrowing tip mounted between said arms adjacent the other end of said shank for pivotal'movement thereon, rearwardly diverging tail sections on saidfiuke forming a rigid wedge with the apex thereof extending along said base, said tail sections being secured directly to said fluke each to form a continuation of one side of said fluke, said fluke being pivoted about an axis extending substantially parallel to said base and intermediate the planes of said tail sections, and stop means on said shank between the planes of said tail sections engaeable with portions thereon to limit the extent of said pivotal movement.

3. An anchor comprising a fluke having a bottom-engaging tip and a relatively wide base, diverging tail sections on said fluke forminga wedge with the apex of said Wedge at said base, an elongated shank having an extremity beyond said tip with an eye for connection to an anchor line, branched arms of said shank extending from said extremity adjacent to but spaced from the edges of said fluke, and a pivotal connection between said branched arms and said fluke adjacent to said base to provide pivotal movement about an axis parallel to the length of said base, said arms of said shank extending on both sides of said pivotal connection with the portion of said arms on one side of said pivotal connection lying between the plane of said diverging tail sections, and having a connecting bar between such portions of said arms providing a stop between said tail sections to limit the extent of pivotal movement of said shank with respect to said fluke.

4. The anchor defined in claim 3 wherein said fluke has an opening therethrough to enable ready release of said anchor from muddy bottoms by upward pull on said shank.

5. An anchor comprising: an elongate shank having means at one end thereof for attachment to an anchor line, a fluke having a relatively wide base and a burrowing tip, rearwardly diverging tail plates rigidly secured to said fluke and forming a wedge with the apex thereof extending along said base, journal means pivotally mounting said fluke on the other end of said shank for pivotal movement about an axis parallel to and rearward of said apex, and stop means on said shank between the planes of said tail plates engageable with portions thereton to limit the extent of said pivotal movement in opposite directions, said axis being spaced rearward from said apex far enough that when said shank is generally horizontally disposed and said fluke is pivoted downward to the full extent limited by said stop means a substantial portion of the upper one of said tail plates is disposed below the plane of said shank, said tail plates being disposed at angles relative to said fluke so that the angle of said upper tail plate relative to said shank cannot exceed 90 degrees.

6. The anchor defined in claim 5 wherein the angle between said diverging tail sections is less than 90.

7. The anchor defined in claim 6 wherein said stop means are arranged to limit said pivotal movement of the fluke in each direction to an angle less than 45 relative to said shank.

8. The anchor defined in claim 5 wherein said tail plates are disposed on opposite sides of said plane of the fluke each at an angle thereto of substantially 9. The anchor defined in claim 8 wherein said stop means are disposed relative to said portions so as to limit the extent of the pivotal movement of said fluke to 35 on each side of said shank.

References Cited in the file of this patent UNITED STATES PATENTS 2,282,566 Danforth May 12, 1942 2,696,187 Pitzipio Dec. 7, 1954 FOREIGN PATENTS 617,367 Great Britain Feb. 4, 1949 647,932 Great Britain Dec. 28, 1950