Abstract:
The apparatus and method of the present invention provide a crewmember with the ability to retrieve the halyard and shackle at the head of a mast of a contemporary sailing vessel from the deck. A clamshell device containing a magnetized component is pre-installed on the halyard shackle and a related magnetically active cylinder is attached to a companion non-loaded halyard running just beside the loaded halyard. The clamshell is attached at the top of the shackle just below the halyard that is attached to the shackle.

Description:
This non-provisional utility patent application claims the benefit under 35 USC 119(e) of provisional application 61/630,487 filed Dec. 29, 2011. 
     The subject of this invention relates to sailing vessels and related rigging. Specifically, the disclosed invention presents an apparatus and method for its use that facilitates retrieval of unattached halyards of a sailing vessel without the need for a crewmember to ascend the mast, thereby eliminating the risk and expense associated with such activity. 
     BACKGROUND OF THE INVENTION 
     Sailing vessels have existed for centuries. While modern sailing vessels have taken advantage of the progress made in materials and methods science, the fundamental operation of a sailing vessel remains the same. That is, depending on wind conditions and direction, a sail or sails must be raised, lowered, or trimmed to optimize the performance of the craft. Most modern sailboats have at least two sails that are used and typically have additional halyards included for spares and for specialty sails. 
     Modernly, as in historical times, sails are raised and lowered via a system of lines or halyards attached to the heads of sails. For clarity, the head of the sail is the top most portion of a triangular sail, which is the most common shape for modern sailboats. The halyard is attached to sail with a clasping device typically called a shackle having a curved and enclosed top and an open section with a pin that is placed through a metal or plastic grommet or cringle at the head of the sail. The top most portion of the shackle is used to attach the halyard. 
     Since the marine environment is corrosive to high zinc alloys (and other ferrous metals), shackles and most marine hardware is either 316 grade stainless steel, plastic, carbon fiber or similar material. Such marine hardware serves several purposes, and for purposes of the present invention, it is only noted here that such hardware in addition to the shackle does exist. 
     If a shackle should accidentally become disconnected from a sail, for example, if the pin holding the sail cringle is dislodged, the shackle will be difficult to retrieve since the wind will tend to move the shackle away from the vessel or the weight of the opposite end of the line will bring the shackle to the top of the mast. In fact, at present, the only practical way to retrieve the shackle for reattachment is to either ascend the mast and manually retrieve it or try to fashion some sort of snagging device. In the first case, this involves either a crewmember hoisting themselves aloft, a crewmember being hoisted aloft by another, or using pre-installed mast steps. In the second case, this involves multiple lines whipping around with a crewmember trying to snag it. Both of these situations are dangerous and time consuming operations. 
     In the case of the first contemporary method, if a crewmember wishes to hoist themselves aloft, products such as the TopClimber from ATN, Inc., Hollywood, Fla., may be used. This device allows a crewmember to place each foot in a loop and, using upper body strength and alternate foot movement, slowly pull themselves to the head of the mast. 
     Alternatively, a classic “bosun&#39;s chair” may be used. For this method, the crewmember sits in a seat and is pulled aloft by one or more other crewmembers. It is possible for a single crewmember to use the chair method, but it is difficult and requires significant strength. 
     A third contemporary method for ascending the mast is to use pre-installed steps, either fixed or folding, such as the folding mast step from Sea Dog, Everett, Wash. In this method the mast has had a set of folding steps permanently attached to the sides of the mast. When required for maintenance, the steps are folder outward and the crewmember climbs aloft a step at a time. When the crewmember descends, each step is folded inward to prevent fowling of other rigging. 
     In the case of the snag method, a crewmember uses a weighted grappling hook with one or more tines, casting the device upward to retrieve the unattached shackle. Of course, this method has some very dangerous and damaging side effects. For example, if the device fails to retrieve the unattached shackle it will necessarily fall back to the deck causing damage to the boat and/or other crewmembers. 
     Each of the above methods has its drawbacks. For each, one or more crewmembers are put at risk of injury due to falling, tangling or other physical failure modes. Additionally, damage to the craft itself is likely if the snag method is attempted. Beyond the danger, because all present methods use the existing halyard system, the crewmember can have trouble reaching the actual masthead to accomplish the retrieval. 
     While the step method seems to be satisfactory, it involves expense and has the severe drawback of creating a potential interference to the running rigging when the vessel is underway. In addition, snagging a line either from the deck or at the masthead involves similar drawbacks. Also, with all methods, while relatively easy to accomplish at dockside or while anchored in calm waters, neither can be used safely while under way or in rough water. 
     What would be desirable would be an apparatus and method that would allow a single crewmember to accomplish the retrieval task from the safety of the deck. 
     SUMMARY OF THE INVENTION 
     The apparatus and method of the present invention provide a crewmember with the ability to retrieve the halyard and shackle at the head of a mast of a contemporary sailing vessel from the deck. A clamshell device containing a magnetized component is pre-installed on the halyard shackle and a related magnetically active cylinder is attached to a companion non-loaded halyard running just beside the loaded halyard. The clamshell is attached at the top of the shackle just below the halyard that is attached to the shackle. 
     The clamshell device of the apparatus of the present invention is generally comprised of a two-part enclosure that is fastened together around the top part of the shackle, one or more permanent magnets of sufficient field strength mounted in opposite pole directions, each of the one or more permanent magnets contacting a thin ferromagnetic rectangular metal component, one pin or screw, and one cotter pin or nut used to ensure the two halves of the clamshell device stay together. The various parts have been dimensioned to allow use with a range of halyard diameters. 
     The companion non-loaded halyard of the present invention is configured to run in parallel with the loaded halyard. This halyard may be of significantly less strength since the only load seen by this halyard is the combination of the magnetically active cylinder and the shackle from the loaded halyard. Since this is the case, the operating hardware, for example, the pulley at the mast head and the magnetically active cylinder attachment hardware may be of limited strength as well. 
     In use, a crewmember pre-attaches the clamshell device about the halyard just below the top of the existing sail cringle shackle, then attaches the sail in the normal fashion. A second, smaller diameter non-load bearing retriever halyard is run along the same route as the load bearing shackle. Fastened about this retriever halyard is a ferrous cylinder. If the sail cringle should become detached from the shackle, the crewmember brings the separated shackle to the mast head and secures it. Then, the crewmember attaches a keeper line to the retriever halyard with the ferrous cylinder attached and raises the ferrous cylinder to the mast head. When the ferrous cylinder becomes proximate to the clamshell device, the magnetic force will join them. The crewmember then pulls on the keeper line and retrieves both halyards. 
     Several embodiments of the present invention are disclosed. Each of these embodiments is dimensioned and constructed to allow use over a broad range of halyard shackle sizes, thus may be used on the vast majority of modern day sailing vessels. Each of the embodiments of the present invention is discussed in detail in conjunction with the drawings listed below. As will be evident, the apparatus and method of the present invention overcomes the disadvantages of the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1 : is an overall exploded isometric view of the clamshell device of the present invention. 
         FIG. 2 : is a side view of the clamshell device of the present invention showing the relationship of the various parts. 
         FIG. 3 : is a sectional view of the ferrous cylinder assembly of the present invention. 
         FIG. 4A : is an isometric view of one half of the clamshell device with dimensional annotation. 
         FIG. 4B : is an isometric view of one half of the ferrous cylinder with dimensional annotation. 
         FIG. 5 : is an isometric view of the clamshell device attached to a typical shackle. 
         FIG. 6A : shows the initial operating condition of a sail. 
         FIG. 6B : shows the condition just after the sail has become detached from its shackle. 
         FIG. 6C : shows the non load bearing halyard after having been hoisted aloft. 
         FIG. 6D : shows the capture of the loose shackle. 
         FIG. 6E : shows the loose load bearing halyard being down-hauled. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As described briefly above, the method and apparatus of the present invention solves the problems associated with prior art loose halyard retrieval.  FIG. 1  provides an overview  10  of the clamshell device of the present invention. 
     The clamshell assembly  10  of the present invention is comprised of two halves  20 A and  20 B. They are mirror images of each other except for snap tabs  24 A and tab slots  24 B. In all embodiments the snap tabs  24 A and tab slots  24 B serve to properly orient the various components of the clamshell assembly  10 . In one embodiment the snap tabs  24 A and tab slots  24 B are used not only for orientation, but also provide the clamping force required to keep the two halves of the clamshell assembly  10  together. In a separate embodiment, a bolt  60  passes through holes  22 A,  32 A,  42 ,  32 B and  20 B, mating with nut  65 . The combination of the bolt  60  and the nut  65  provide the requisite clamping force in this embodiment. 
     The two clamshell halves  20 A and  20 B are made from a non-ferrous material, for example, polycarbonate. Polycarbonate is the preferred material due to its high impact resistance, ability to withstand weather, and ability to perform in both fresh and salt water environments. As will be clear to those of skill in the art, other materials such as aluminum, polyvinyl chloride or some organic polymer may be used without departing from the spirit of the invention, thus the scope of the invention is limited only by the claims. For the balance of the discussion of the present invention the bolt-fixed embodiment will be used; however, it will be recognized by those of skill in the art that the discussion applies equally to the snap-fixed embodiment. 
     A permanent magnet  40  is located between ferrous strips  30 A and  30 B and dimensioned such that when the two halves of the clamshell device  10  are fastened together by bolt  60  and nut  65 , the combination of the ferrous strips  30 A and  30 B and the permanent magnet  40  completely fill the cavities  26 A [not shown] and  26 B. In a preferred embodiment, permanent magnet  40  is a type DBS-5050 alnico [an alloy of aluminum, nickel and cobalt] from Dura Magnetics, Inc, Sylvania, Ohio. It will be understood that other magnet types, for example neodymium or molybdenum, could be used without departing from the scope of the invention, thus the preferred embodiment is exemplary only. It will be further recognized that the specific dimensions of the preferred embodiment permanent magnet can change depending on the size of the clamshell without departing from the scope of the invention. 
     Ferrous strips  30 A and  30 B are identical and are made from B4A2 low carbon steel in a preferred embodiment, but any mild steel of sufficient permeability could be used. Other ferro-magnetic materials, such as carbon fiber infused with iron fillings could also be used while remaining inside the ambit of the claims. Bolt  60  is a ferritic stainless steel bolt of sufficient length to pass through holes  22 A,  32 A,  42 ,  32 B, and  22 B with sufficient thread to fully engage nut  65 . Ferritic stainless steel material is used in order to extend the flux lines of permanent magnet  40 . Nut  65  is of the nylon insert lock nut type in conventional use and is employed because of its inherent resistance to vibration and weather. Both the nut  65  and the bolt  60  may be obtained from a plurality of sources and are thus not discussed in great detail here. Moreover, while ferritic stainless steel is used in the preferred embodiment, it will be clear that any ferrous bolt and nut could be used. 
       FIG. 2  provides assembly details for the clamshell assembly  10 . The two halves of the clamshell assembly  10 ,  20 A and  20 B, can be made from a variety of materials including aluminum, plastic or carbon fiber, but as noted above, the preferred embodiment uses polycarbonate. As can be seen, tab  24 A snaps into slot  24 B [not shown for clarity, but assumed to follow the contours of the tab] and in this embodiment bolt  60  and nut  65  are used to insure that the two halves of the clamshell assembly  10  do not separate. As mentioned above, in an alternative embodiment tabs  24 A and slots  24 B are configured such that they provide the requisite captive force. In this side view, it can be seen that ferrous strips  30 A and  30 B in combination with permanent magnet  40  completely fill the cavity formed by the two halves of the clamshell assembly  10 . 
     Looking now at  FIG. 3 , the ferrous cylinder assembly  70  is described in detail. A length of ferrous bar stock  72  of an appropriate diameter has two eye screws  74 A and  74 B threaded into it. Threads  76 A and  76 B are of sufficient length to assure that the eye screws  74 A and  74 B will not be pulled out under the pressure of hauling on the attached non load bearing halyard. The non load bearing halyard discussed briefly above and in detail below in conjunction with  FIG. 6  attaches to the ferrous cylinder  72  via eye screws  74 A and  74 B. Ferrous cylinder  72 , eye screw  74 A and eye screw  74 B are made from B4A2 stock in a preferred embodiment. But as with other ferrous components of the present invention, other ferrous materials may be used without exceeding the scope of the invention. 
       FIG. 4  provides dimensional details of both the clamshell assembly [ 10  of  FIG. 1 ] and the ferrous cylinder assembly  70 . Note that only one half of the clamshell  20 B is shown. It will be understood that the other half will have identical dimensions. Beginning with  FIG. 4A , clamshell half  20 B has two identical semicircular openings O each with a diameter D s  as shown. Diameter D s  is such that it will easily fit about the upper portion of a common shackle and can be varied to accommodate various shackle shank diameters thereby making the device useful for a wide variety of halyards. By way of example, but not to be read as a limitation, dimension D s  could be any of 0.25 inches, 0.38 inches or 0.50 inches depending on the type of load bearing halyard in use. Other dimensions are equally possible. It should be noted that the actual dimension needed is a function of the type of halyard material, its diameter and other factors specific to the halyard being used. 
     Dimension L s  in  FIG. 4A  is chosen to allow the clamshell assembly to easily fit on the upper shanks of a contemporary long reach shackle. Contemporary long reach shackles have a vertical shank length of anywhere from four to eight inches. Dimension L s  is chosen such that it covers just less than half of the vertical shank dimension, thus for a four inch long reach shackle, dimension L s  would be 1.9 inches. This dimension will vary depending on the type of cringle, the weight of the sail and the diameter of the load bearing halyard. 
       FIG. 4B  provides the dimensional detail of the ferrous cylinder assembly  70 . Note that the ferrous cylinder is shown without the eye screws for clarity, but it is understood that the eye screws are implied. Length L c  is chosen to allow the permanent magnet contained in the clamshell device to attract ferrous cylinder assembly  70  over a sufficient vertical range during the retrieval process. By way of example, for the four inch long reach shackle discussed just above, dimension L c  would be 1.9 inches and for an eight inch long reach shackle the dimension L c  would be 3.5 inches. 
     Dimension D c  in  FIG. 4B  is selected to allow the ferrous cylinder assembly  70  to fit easily inside the clamshell opening between the semicircles O in  FIG. 4A . This is done so that when the ferrous cylinder assembly  70  is being hauled aloft it will have the ability to achieve close proximity to the ferrous strips [ 32 A and  32 B of  FIG. 1 ]. Again using the example of a four inch long reach shackle, this dimension would be on the order of 0.75 inches. The dimension needs to be this small in order to accommodate the wall thickness of semicircles O. As with all other dimensions, D c  will vary with the type of cringle, the weight of the sail and the diameter of the load bearing halyard. 
       FIG. 5  shows the assembly  100  of the clamshell assembly  10  of the present invention installed on a typical contemporary long reach shackle  90 . On some contemporary long reach shackles a support member  94  is provided at about the halfway point on the vertical shanks of the shackle. The clamshell assembly  10  of the present invention is sized such that it may be used with this type of shackle as well as those shackles that do not have the support member  94 . Pin  92  is used to attach the shackle  90  to the cringle of a sail. In this embodiment, bolt  60  is used to both provide the clamping force for the two clamshell halves and to extend the magnetic field of the internal permanent magnet [ 40  of  FIG. 1 ]. 
       FIG. 6  is a graphical discussion  200  of the method of the present invention. Beginning with  FIG. 6A , the sail  80  of a contemporary sailing craft is attached to load bearing halyard  85  by means of shackle  90  via pin  92 . The clamshell assembly  10  of the present invention has been properly attached to shackle  90 . Non load bearing halyard  75  has been rigged to run in close proximity to halyard  85 , following essentially the same route, but is otherwise unloaded during normal operation. 
     For purposes of this discussion it will be assumed that a purpose-built non load bearing halyard has been run in parallel with the load bearing halyard. It will be recognized that other non load bearing halyards could be used, for example, the topping lift of a sloop rigged vessel could be used rather than a dedicated halyard, and likewise. The spare halyard used to raise and lower a Genoa jib could be used. For purposes of the present invention the term non loaded halyard is general, and is meant to cover all instances of a halyard separate from the one that has had a shackle break free. 
     In  FIG. 6B  for some reason the sail has been detached from the shackle  90 , in this case by the dislodging of pin  92  (not shown). At this point in time the load bearing halyard, with the clamshell assembly  10  attached, is loose and most likely at the head of the mast due to the weight of the halyard running down to the deck of the sailing craft. If not, a crewmember can up-haul the load bearing halyard until the shackle is at the masthead. This is done to prevent the shackle from whipping about. At this time as well it is likely that the sail that was attached to the shackle  90  has dropped at least part of the way to the deck, making the situation very hazardous. 
     In  FIG. 6C  non load bearing halyard  75  has been hoisted aloft as shown by directional arrow D 1 . In this example the non load bearing halyard is a continuous loop, so no keeper line needs to be attached. However, it is possible to have a non load bearing halyard configured such that a keeper line needs to be attached in order to down haul the non load bearing halyard once it has been hauled aloft. Ferrous cylinder assembly  70  has been hoisted aloft as well since it is snuggly attached to non load bearing halyard  75 . 
     In  FIG. 6D  the ferrous cylinder assembly  70  has been forced in direction D 2  by the magnetic field of the permanent magnet contained within the clamshell assembly  10 . If necessary, this may be accomplished by an easy swinging motion of the non loaded halyard if the inherent magnetic field fails to place the ferrous cylinder assembly  70  close enough to the clamshell assembly  10 . Non load bearing halyard  75  is now in very close proximity to clamshell assembly  10  and is held there by the magnetic force of the permanent magnet contained within the clamshell assembly  10 . 
       FIG. 6E  shows the non load bearing halyard  75  being down-hauled toward the deck by the directional arrow D 3 . Shackle  90  and clamshell assembly  10  will necessarily be hauled down as well due to the captive force of the permanent magnet in concert with the ferrous cylinder assembly. Once at the deck, the ferrous cylinder assembly  70  and the clamshell assembly  10  may be separated, the sail reattached to shackle  90  and the sail hauled aloft in the normal manner. 
     In the manner described above, a crewmember is able to retrieve a loose shackle from the deck of a sailing craft without the need to engage in risky and complicated retrieval methods. Moreover, the method of the present invention may be used away from dockside or in rough waters. 
     A first advantage of the present invention is the ability to retrieve a loose halyard from the deck of a sailing craft. This may be accomplished in the widest range of sailing conditions including dockside or under way. 
     A second advantage of the present invention is the significant increase in safety to the crew. There is no need to hoist a crewmember aloft, and no need to be casting such devices as grappling hooks about the craft. 
     A third advantage of the present invention is cost. The clamshell device of the present invention can be manufactured from a variety of materials and is easy to install and use, thus avoid potentially costly repairs in a boatyard. 
     A fourth advantage of the present invention is its ease of use. A single crewmember can retrieve a disconnected sail in a variety of conditions. 
     A fifth advantage of the present invention is that it may be used with a wide variety of sails including main sails, jibs, Genoa jibs and gaff rigged booms.