US3771486A

US3771486A - Twin fluke anchor having improved shank-crown contact

Info

Publication number: US3771486A
Application number: US00178232A
Authority: US
Inventors: Hungerford D Comstock
Original assignee: Brunswick Corp
Current assignee: Brunswick Corp
Priority date: 1971-09-07
Filing date: 1971-09-07
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13
Also published as: JPS4862189A; GB1371130A; AU4638572A; CA964529A; DE2243591A1; AU467904B2; IT967219B; FR2152164A5

Abstract

A twin fluke anchor in which the shank is limited in angular displacement by engagement with the leading edge of the crown side wall, thus allowing increased crown-shank engagement forces.

Description

United States Patent [191 Hungerford Nov. 13, 1973 TWIN FLUKE ANCHOR HAVING IMPROVED SHANK-CROWN CONTACT [75] inventor: Daniel Comstock Hungerford, North Palm Beach, Fla.

[73] Assignee: Brunswick Corporation, Skokie, Ill.

[22] Filed: Sept. 7, 1971 [21] Appl. No.: 178,232

[52] US. Cl 114/208 R [51] Int. Cl B63b 21/44 [58] Field of Search 114/206, 207, 208 R [56] References Cited UNITED STATES PATENTS 3,332,387 7/1967 Winslow 114/208 R 3,382,835 5/1968 McGuire 114/208 R Primary Examiner-Milton Buchler Assistant Examiner-Galen L. Barefoot AttorneyBarry L. Haley [5 7] ABSTRACT A twin fluke anchor in which the shank is limited in angular displacement by engagement with the leading edge of the crown side wall, thus allowing increased crown-shank engagement forces.

6 Claims, 8 Drawing Figures PATENTEI] NOV 13 I975 SHEET 1 UF 2 pE/OE r497 PATENIEDHOV 13 ms 3.771.486

sum 2 BF 2 BY 73 m 3 JQTTOE/VEY TWIN FLUKE ANCHOR HAVING IMPROVED SHANK-CROWN CONTACT BACKGROUND OF THE INVENTION This invention relates generally to the field of anchors, and more specifically to a twin fluke anchor having an improved shank angular displacement stop.

With a twin fluke anchor, in order to achieve proper fluke penetration and holding in the sea bottom for maximum force, a critical angle of about 32 between the plane of the flukes and the shank must be established and maintained. In the past this angle was formed when the lateral edge of the shank contacted the crown plate leading edge. The contact forces acted to separate the crown plate from the perpendicularly coupled crown walls and to produce a shear force in the plane of the crown plate. The result if too large a force is presented is the destruction of the crown or distortion of the crown plate such that the optimum maximum fluke-shank angle has been exceeded thus making the anchor unuseable. These problems prohibit or reduce the use of lightweight. metals such as aluminum because of their lower shear force limits.

Applicants invention replaces the shank-crown plate shear force with a crown side wall leading edge compression force capable of withstanding much greater shank-crown contact forces for a given size and weight anchor.

BRIEF DESCRIPTION OF THE INVENTION A twin fluke anchor having a crown, a pair of flukes joined to said crown, a shank pivotally coupled to said crown, the crown having a pair of oppositely disposed crown plates, a pair of parallel side walls joined to said crown plates, the side walls being oriented substantially parallel to the plane of movement of the shank, and a contact means coupled to said shank engageable with the leading edge of at least one crown side wall to limit the angular displacement of said shank substantially equally on each side of a plane containing the flukes. The contact means or the leading edge of the crown side wall is contoured so that at engagement the shank is limited to a predetermined angular value with respect to said fluke plane. The shank is prevented from exerting large forces on the crown plates.

It is an object of this invention to provide a twin fluke anchor having increased holding capabilities.

It is another object of this invention to provide an anchor with improved crown-shank contact.

And yet another object of this invention is to provide an anchor having a crown-shank engagement with increased structural integrity for defining maximum shank angular movement.

In accordance with these and other objects which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a showing of the prior art.

FIG. 2a is a side elevation view of applicants crown and shank assembly.

FIG. 2b is a side elevation view showing an alternate embodiment with a different shank stop angle.

FIG. 20 is a sie elevation view showing another alternative embodiment with a different shank stop angle.

FIG. 3 is an end-on elevation of applicants invention.

FIG. 4 is a diagram of the angular relationships on applicants stop surface.

FIG. 5 is a perspective view of an anchor in accordance with applicants invention.

FIG. 6 is a side elevation view of an alternate embodiment of applicants invention.

PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings, and in particular to FIG. 1, an anchor crown 10 is shown as prior art. The crown 10 has a pair of diverging

crown plates

12 and 16 which are coupled to opposite edges of crown side plates 14. Shank pivot shaft 20 is coupled at each end to one of the side plates 14 and the shank 18 is pivotally joined to the shaft 20. Line AA represents the fluke plane axis which is fixed with respect to the crown (the flukes being rigidly coupled to the crown). The flukes lie in the fluke plane and are symetrical about the fluke plane axis AA. The prior art shows shank 18 moveable about each side of the fluke. plane axis AA the optimum maximum amount of 32. The shank is stopped at its outer limits on each side of the axis AA by either

crown plate

12 or 16. The lateral edge of shank 18 directly contacts the leading edge of crown plate 12 or plate 16, and quite often the force from shank 18 on the plate is sufficient to separate the plate 12 from the side walls 14 or distort the leading edge of the plate 12 such that a new, undesirable angle between the shank l8 and the axis AA would be created. The plate arrangement shown is unsatisfactory for use with light weight materials or large shank forces.

Applicants device for overcoming these problems is shown in FIG. 2a. Applicants crown 22 has diverging

crown plates

24 and 28 coupled to opposite edges of parallel

crown side plates

26 and 34. A shank pivot shaft 32 is coupled between

side plates

26 and 34, and shank 30 is pivotally coupled near one end about the shaft 32. The shank 30 is moveable from a center position 1 which lies in fluke plane axis BB to maximum

angular positions

2 and 3 above and below the axis 8-8 respectively. A pair of shank stops 36 and 38 having angularly pointing surfaces are disposed on each side of shank 30 and are thick enough and project out from the shank surface so that at the maximum

angular positions

2 and 3, the shank stops 36 and 38 contact the vertical leading edges of

crown side walls

26 and 34 respectively. The stopping means 36 and 38 move in a circular are as the shank 3 is moved about the pivot shaft 32 (FIG. 2a). The stopping means project outward from the shank (FIG. 3) and are positioned radially from the pivot shaft 32 a distance so that their end faces will engage the side

wall leading edges

26 and 34 when the center of the shank is 32 on either side of fluke plane axis BB. Both stopping means are coupled to the shank by a long screw 42. Any conventional holding means would be satisfactory.

The contact portion of the shank stopping means may be of any geometrical shape, but as shown in the preferred embodiment, fiat surface engagement with flat surface will distribute the force on the crown wall leading edge more evenly. In FIG. 2a the leading edges of the crown side walls are perpendicular with respect to the fluke plane. In FIGS. 2b and 2c, the leading edges are obliquely and acutely angled respectively with the fluke plane. Thus in each example, the angle of the contact surface of stopping means 36 with respect to the shank longitudinal axis is selected so that engagement with the crown side wall leading edge surface will be between flat surfaces. This angle is established (FIG. 4) generally after having chosen the maximum shank fluke plane angle to be utilized (e.g. 32), by determining the angle between the leading edge of the crown side wall and the fluke plane (shank neutral position) (90) and subtracting the maximum shank-fluke plane angle (32) which results in the required angle (58) between the contacting surface of the stopping means and the shank longitudinal axis (same as the fluke plane axis when the shank is in the neutral position). Because the shank pivot shaft is behind the crown side wall leading edge, the distance of the stopping means from the shank pivot shaft will vary as a function of the angle between the crown wall leading edge and the fluke plane. In FIG. 4, line DD represents the crown wall leading edge surface, line C-C the longitudinal axis of the shank and line EE the contacting surface of the stopping means 36. With an obliquely angled crown wall leading edge as in FIG. 2b, the contacting surface of stopping means 36 is perpendicular to theshank longitudinal axis (line BB when shank is in the neutral position), while in FIG. 20 both the crown wall leading edge and the contacting surface of stopping means 36 are acutely angled with respect to line 8-8. In FIGS. 2b and 20,

positions

1, 2, and 3 represent the shank neutral and maximum positions respectively with the stopping means 36 engaged with the leading edges of crown wall side 26 on each side of the fluke plane axis B-B.

FIG. shows a twin fluke anchor constructed according to applicants invention. Stopping means 42 are disposed on each side of shank 30 and engage

crown side walls

26 and 34 to limit shank movement on either side of line B-B which lies in' the plane of

flukes

38 and 40 to the optimum maximum angle of 32. The

flukes

38 and 40 are coupled to stock 52 and the

crown side walls

26 and 34 in any standard way.

FIG. 6 shows an alternate embodiment with crown side wall 46 coupled at top and bottom to crown plates 44 and 48. The leading edge of side wall 46 is contoured in a hill-and-dale fashion so as to receive circular projecting member 52 which projects away from the shank 50 sides. The

positions

1, 2, and 3 of shank 50 show the neutral (fluke plane axis), upper maximum and lower maximum respectively. At maximum shank angles, the projecting member is engaged in a circular projecting member is provided on each side of shank 50 (not shown) and likewise both side wall leading edges are contoured the same. The projecting members 54 act to stop and limit the angular movement of shank 50 at predetermined optimum angles on either side of the fluke plane axis B-B.

Although the shank stopping means or projecting means has been shown to be a wedge or circular projection from the shank side, any shank flange or projecting element that overlaps the leading edge and engages the crown wall leading edge so that the crown plates are not engaged would be satisfactory to practice applicants invention.

The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.

What I claim is:

l. A twin fluke anchor comprising:

a stock;

a pair of flukes coupled at their edges to said stock;

a crown having a pair'of oppositely disposed side walls and a pair of crown plates oppositely disposed joining the top edges and bottom edges of said side walls;

shank pivot means connected to said crown side walls;

a shank pivotally connected at one end to said pivot means; and

shank stopping means for stopping shank angular pivotal motion secured to said shank and engageable with the leading edges of said side walls at predetermined angular positions of said shank on either side of a plane containing'said flukes.

2. An anchor as in claim 1, wherein:

said stopping means is a wedge shaped block having two surfaces angularly disposed facing said leading edge of said crown side walls, with each surface flushly engageably with the leading edge surface at predetermined maximumangular positions of said shank and fluke plane.

3. An anchor as in claim 1, wherein:

said stopping means is a shaped element projecting from said shank lateral surface; and

said crown side wall leading edge is contoured to engage flushly with said shaped projecting element.

4. A twin fluke anchor comprising:

a stock;

a crown having a pair of oppositely disposed side walls and a pair of crown plates oppositely disposed joining the top edges and the bottom edges of said side walls;

- shank pivot means connected to crown side walls;

a shank pivotally connected at one end to said pivot means; and

means connected to said shank for stopping the pivotal motion of said shank, said stopping means engageable with the leading edges of said side walls at a predetermined angular position of said shank on either side of a plane containing said flukes.

5. In a twin fluke anchor having a stock, a pair of flukes coupled along their back edges to said stock, a crown coupled to said stock, and a shank pivotally coupled to saidcrown, the improvement comprising:

a shank stop for stopping shank angular pivotal motion connected to said shank and engageable with at least one of the front planar faces of said crown side walls, said side walls substantially parallel to the plane of pivotal movement of said shank, said shank stop engaging the front planar face of said side wall edges stopping the shank at a predetermined angle of pivotal movement relative to the plane of said flukes.

6. A twin fluke anchor comprising:

a pivot rod connecting said flukes;

an elongated shank pivotally connected between said flukes to said pivot rod;

a crown housing connected to said pivot rod and extending about said shank on all sides, said crown housing having a first side and a second side substantially parallel to the plane of motion of said shank; and

a shank angular pivotal motion stopping means for stopping shank angular pivotal motion connected to said shank and engageable with the front face of said first and said second housing sides to determine a maximum angle of movement of said shank on either side of said flukes.

Claims

1. A twin fluke anchor comprising: a stock; a pair of flukes coupled at their edges to said stock; a crown having a pair of oppositely disposed side walls and a pair of crown plates oppositely disposed joining the top edges and bottom edges of said side walls; shank pivot means connected to said crown side walls; a shank pivotally connected at one end to said pivot means; and shank stopping means for stopping shank angular pivotal motion secured to said shank and engageable with the leading edges of said side walls at predetermined angular positions of said shank on either side of a plane containing said flukes.

2. An anchor as in claim 1, wherein: said stopping means is a wedge shaped block having two surfaces angularly disposed facing said leading edge of said crown side walls, with each surface flushly engageably with the leading edge surface at predetermined maximum angular positions of said shank and fluke plane.

3. An anchor as in claim 1, wherein: said stopping means is a shaped element projecting from said shank lateral surface; and said crown side wAll leading edge is contoured to engage flushly with said shaped projecting element.

4. A twin fluke anchor comprising: a stock; a crown having a pair of oppositely disposed side walls and a pair of crown plates oppositely disposed joining the top edges and the bottom edges of said side walls; shank pivot means connected to crown side walls; a shank pivotally connected at one end to said pivot means; and means connected to said shank for stopping the pivotal motion of said shank, said stopping means engageable with the leading edges of said side walls at a predetermined angular position of said shank on either side of a plane containing said flukes.

5. In a twin fluke anchor having a stock, a pair of flukes coupled along their back edges to said stock, a crown coupled to said stock, and a shank pivotally coupled to said crown, the improvement comprising: a shank stop for stopping shank angular pivotal motion connected to said shank and engageable with at least one of the front planar faces of said crown side walls, said side walls substantially parallel to the plane of pivotal movement of said shank, said shank stop engaging the front planar face of said side wall edges stopping the shank at a predetermined angle of pivotal movement relative to the plane of said flukes.

6. A twin fluke anchor comprising: two flat flukes; a pivot rod connecting said flukes; an elongated shank pivotally connected between said flukes to said pivot rod; a crown housing connected to said pivot rod and extending about said shank on all sides, said crown housing having a first side and a second side substantially parallel to the plane of motion of said shank; and a shank angular pivotal motion stopping means for stopping shank angular pivotal motion connected to said shank and engageable with the front face of said first and said second housing sides to determine a maximum angle of movement of said shank on either side of said flukes.