Abstract:
An improved anchor comprising a longitudinal shank assembly, a fluke assembly mounted on an axle that is perpendicularly disposed with respect to the shank assembly and a release mechanism that allows, when tripped, the fluke assembly to rotate freely to form an angle of 180 degrees with respect to the shank assembly. The release mechanism is designed so that tripping occurs when the angle of the chain or cable is above a desired critical angle.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention. 
     This invention relates to anchors, and in particular, to those anchors provided with pivotally mounted flukes and with a release mechanism to facilitate its unmooring. 
     2. Description of the Prior Art. 
     An anchor moors a vessel to the sea bed, generally by a combination of its own weight and by hooking itself into the bottom. See The Illustrated Science and Invention Encyclopedia, H. S. Stuttman Co., Inc., Publishers, N.Y., Vol. 1, page 110. An ideal anchor is designed so that a near horizontal pull causes it to dig itself in firmly, but an upward pull dislodges it easily. It is attached to the vessel by a cable--this is a heavy chain on large ships. Anchors in use today provide a more or less firm mooring but require winching in the cable and running the vessel over the anchor&#39;s position for its unmooring. When the cable is more or less vertical the anchor should dislodge. However, it does not always dislodge easily. Sometimes, an underwater utility cable or mangrove root gets caught between the flukes and pulling the anchor out is just an exercise in futility. One of the most popular anchors, the Danforth anchor, is particularly susceptible to this problem. 
     SUMMARY OF THE INVENTION 
     It is the main object of the present invention to provide an anchor capable of reliably mooring and unmooring a vessel easily. Another object of this invention is to provide an inexpensive anchor requiring a minimum of storage space aboard the vessel. 
     Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings, in which: 
     FIG. 1 is an oblique view of the preferred embodiment of the present invention. 
     FIG. 1a shows a side cross-section as viewed from line 1A. 
     FIG. 1b represents a partial view of FIG. 1a, from the left. 
     FIG. 2 illustrates a detailed side view of the release mechanism. 
     FIG. 2A shows a top view of the tripping lever element. 
     FIG. 3 illustrates an alternative embodiment for this invention incorporating hinged tripping palms. 
     FIG. 3a shows a side cross-section as viewed from line 3A. 
     FIG. 4 illustrates a detailed side view of an alternative release mechanism. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIG. 1, where the preferred embodiment of the present invention is shown, in perspective, we can observe that the anchor 10 basically comprises a shank assembly 20, a release mechanism 30 and a fluke assembly 40. The shank assembly 30 is composed of two elongated flat rods 21 which are spaced apart from each other by spacer 22 on one end and the other end of the shank assembly terminates with 21 forming a fork with hole 23 substantially towards the end of rods 21. Spacer assembly 22 is basically a pin 25 riveted to the ends of rod 21 and washers 24 sandwiching chain lever 32. Pin 25 is inserted through an opening 31 of chain lever 32 and lever 32 is kept in place by a couple of washers 24 on each side of lever 32. Lever 32 pivots around pin 25 and is pivotally connected to tripping lever 35 which has a fork termination with holes 36 and a riveted pin 37 on one end and the other end being attached to a sliding bar 38 inserted and protruding through a longitudinal slot 26 in said rod 21 and kept in place by a headed termination 39. An elongated flat pivoted member 50 rests on one end on said sliding bar 38 and the other end having stoppers 51 firmly secured, preferably welded, to member 50. As shown in FIGS. 1A and 1B, axle 70 is provided with an integrally built U-shape protrusion 71 positioned in the center of axle 70 and sandwiched between the fork termination of shank assembly 20. Member 50 is pivotally mounted in the center of axle 70 and is capable of rotating around it. By virtue of U-shaped protrusion 71 in axle 70, when member 50, and consequently stoppers 51, rotate it will cause fluke assembly 40 to rotate when stoppers 51 come in contact with protrusion 71 since flukes 42 are rigidly attached to axle 70. And, when fluke assembly 40 pivots around axle 70, member 50 will follow, from the same transmission of forces. In practice, the rotation of the fluke assembly 40 is caused by tripping palm 41, by digging in the seabed of flukes 42 or by the unequal weight distribution of fluke assembly 40. Rotation of the fluke assembly 40 will induce rotation of member 50, as mentioned above, causing it to meet sliding bar 38 on which it rests, thereby preventing any further rotational movement of fluke assembly 40. Once you start pulling chain 80 to dislodge anchor 10, the vessel will travel towards the anchor making the angle A formed between the seabed plane and chain 80 to increase from about 20 or 30 degrees to about 70 degrees, where tripping lever 35 is pulled enough to make member 50 trip and suddenly releasing the force being applied by stopper 51 to protrusion 71 allowing member 50 and fluke assembly 40 to rotate freely, as shown in FIG. 2. Before tripping, flukes 42 could move out a maximum of 45 degrees with respect to the axis of shank assembly 20. After tripping, assuming we are still trying to dislodge the anchor, the fluke assembly 40 will rotate from the 45 degree maximum angle of the flukes in the preferred embodiments towards a 180 degree angle with respect to the shaft assembly 20. The benefits derived are obvious since it will allow the user to pull the flukes out in the opposite direction. This will prevent the user from being forced to pass the vessel over the anchor risking that the anchor cable could get caught with the propeller. Also, if power is not being used and the anchor is being pulled without other help, it is harder to pull the boat towards the anchor as the angle of the anchor cable with respect to the seabed approaches 90 degrees. Mathematically, if we call &#34;1&#34; the longitude of the cable and &#34;x&#34; the horizontal distance from the vessel to a point that is on the sea surface, perpendicularly above the anchor, then the rate of change of force, &#34;F&#34;, with respect to &#34;x&#34; is inversely proportional to &#34;1&#34;. ##EQU1## Therefore, it is submitted that the present mechanism permits dislodging an anchor with a minimum of force required. The tripping angle A, of course, may be adjusted through the selection of dimensions for member 50 and/or tripping lever 35. 
     It is worthwhile noting that the present invention may be practiced with a simplified version of the preferred embodiment which eliminates tripping lever 35, as shown in FIG. 4. Here, we are using the end of chain lever 32 that is not connected to the chain 80 as our tripping member, provided, of course, that said lever 35 is of sufficient length as to be able to intercept member 50 when angle A is less than the desired critical tripping angle. 
     Another alternative embodiment is shown in FIGS. 3 and 3A, wherein hinged tripping palm 43 is hingedly mounted to axle 72 which is parallel to axle 70. The hinged tripping palm 43 in this embodiment pivots around said axle 72 an angle of about 60 degrees and it basically performs the same function as the fixed tripping palms 41 of the above mentioned preferred embodiment. Stopper 44 for hinged tripping palms 43 keeps said members from rotating more than 60 degrees, in the preferred embodiment, while still performing the needed tripping function. 
     It is believed the foregoing description conveys the best understanding of the objects and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense, except as set forth in the following appended claims.