Abstract:
A three legged tripod tower is suitable for attaching to a tow rope using fixed or rotating joints and universal joint structures of various sizes and which may be fixed a various locations for the purposes of towing persons engaged in watersports or for towing objects safely. The structure has only three fixing points on a vessel, namely, one on the bow or stern, and one on each side of the beam, with two mounted to pivot in parallel to enable rapid deployment and stowage. The advantages of this structure include (1) the tripod tower apex will adjust in both forward and rearward directions, and in height, and will fit a variety of vessels of different size, (2) a safety and facilitative feature in having a main pin in the bow or stern leg which will handle the stress of towing and yet enable stowage to a flat position or deployment to a full working position in just moments, and (3) the ability to perform other functions, such as tying up other structures, or “tenting” the cloth top of a boat cover by providing a ridge to prevent pooling of water.

Description:
[0001]    This application is based upon a co-pending United Kingdom Patent application No. 0000014.1 filed on Jan. 5, 2000.  
         FIELD OF THE INVENTION  
         [0002]    This invention relates generally to sports towing equipment, especially of the type used on boats for water skiing, wake boarding and more particularly to a tripod tower with or without various tow fittings which not only provides advantageous tow support, but keeps the tow line high to prevent fouling.  
         BACKGROUND OF THE INVENTION  
         [0003]    Structures for sports towing are not much improved over past methods. Typically, at the most basic level, towing involves the use of a rope attached to a structurally stable portion of a vehicle, such as a boat, with the vehicle simply energized to pull the skier or paraglider, etc.  
           [0004]    The drawbacks to the use of nothing more than attaching a rope to a ring, eyelet or other body part of the vehicle are many. First, where the point from which towing occurs is near the end of the boat, there is an increased chance that the rope may be entangled in the propeller, where the boat is propeller driven, or fouled on the drive unit in the case of a water jet powered boat.  
           [0005]    Another problem is providing a tow structure which is either compatible with or which fails to permit the widest range of utility in the boat&#39;s utilization. Where tow structures arise which interfere with other structures or prohibit the placement and operation of other structures, the overall utility of the vehicle is degraded, and the utility of the vehicle is narrowed to fewer purposes and uses.  
           [0006]    U.S. Pat. No. 5,979,350 of Nov. 9, 1999 illustrates a tow structure, but it is bulky, has a non adjustable towing point, does not fold down to a low profile, and discloses a structure which unfortunately bends and flexes easily, and has too many points of fixation. The number and location of points of fixation, combined with the non-collapsibility of the structure, give significant disadvantages.  
           [0007]    What is therefore needed is a structure which can draw upon the structural integrity of the boat in order to deliver the pulling force to the towed object and rope or connection to the towed object, which can collapse and be re-deployed readily when needed, and which can provide a high, universalist point of pull which puts the state of tow higher in order to improve and facilitate the angle of tow for the skier, as well as to prevent fouling of the tow line during times when the line is not taught.  
         SUMMARY OF THE INVENTION  
         [0008]    A three legged tripod tower is suitable for attaching to a tow rope to a vehicle such as a boat using fixed or adjustable position universal joints or universal joint structures of various sizes and which may be available in various sizes, as well as have wide adjustability both in width size as well as fore and aft, within the applicable size, and be fixed at various locations on a boat for the purposes of towing persons engaged in watersports or for towing objects safely. The structure has only three fixing points on a vessel, namely, one on the bow or stern, and one on each side of the beam. When the structure is deployed, a stable tripod is formed with the center member acting as a bow or stern leg. In deployment and stowage, the center bow or stern leg is allowed free rotation around the main central extent or fulcrum of the beam arms. The advantages of this structure include (1) the tripod tower apex will adjust in both forward and rearward directions, and in height, and will fit a variety of vessels of different size, (2) a safety and facilitative feature in having a main pin in the bow or stern leg which will handle the stress of towing and yet enable stowage to a flat position or deployment to a full working position in just moments, and (3) the ability to perform other functions, such as tying up other structures, or “tenting” the cloth top of a boat cover by providing a ridge to prevent pooling of water. Existing boat covers&#39; functioning is not negatively affected. The tower herein is less prone to flex and distort under tow loads because the bow or stern leg takes the main tension of the load directly. Where the tower is used on an open bow style boat, the bow leg can be used as hand manipulation structure.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which:  
         [0010]    [0010]FIG. 1 is a perspective view of a boat having the tow structure of the in a deployed position;  
         [0011]    [0011]FIG. 2 is plan view looking down on the forward portion of the boat seen in FIG. 1;  
         [0012]    [0012]FIG. 3 is a view looking into the “U” shaped member pivotally mounted onto the opposite sides of the deck of the boat seen in FIGS. 1 &amp; 2;  
         [0013]    [0013]FIG. 4 is a side view of the “U” shaped member pivotally mounted onto the opposite sides of the deck of the boat seen in FIGS. 1 &amp; 2;  
         [0014]    [0014]FIG. 5 is a view as seen in FIG. 4 showing deployment position;  
         [0015]    [0015]FIG. 6 is a side view showing a forward generalized breakdown and stowage with some telescoping, and possibly combined with disconnect of the forward pivoting leg.  
         [0016]    [0016]FIG. 7 illustrates the through threaded attachment of the main leg and the pivot point of the overall “U” shaped member;  
         [0017]    [0017]FIG. 8 is a view looking into the main leg with a view of the pivot assembly seen in plan position;  
         [0018]    [0018]FIG. 9 is a view orthogonal to both the pivoting and main leg;  
         [0019]    [0019]FIG. 10 is a perspective view of a generalized set of members as seen in FIGS.  7  -  9  where the components are welded rather than joined using an over fitting sleeve or clamp;  
         [0020]    [0020]FIG. 11 is a sectional view of the over fitting sleeve or clamp with an internal reinforcing member shown;  
         [0021]    [0021]FIG. 12 is a view taken along line  12  -  12  of FIG. 11;  
         [0022]    [0022]FIG. 13 is a view taken along line  13  -  13  of FIG. 12;  
         [0023]    [0023]FIG. 14 is an exploded view of a variation on the system seen in FIGS.  1  -  13  which uses a variable length pivot tube and side ring fittings;  
         [0024]    [0024]FIG. 15 is a perspective assembled view of the middle fitting seen in FIG. 14; and  
         [0025]    [0025]FIG. 16 is a closeup of the pivoting bases of the overall “U” shaped member seen in FIG. 1;  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]    The description and operation of the structure will be best initially described with reference to FIG. 1. A boat  11  having an upper deck  13  including a port side portion  15 , a starboard side portion  17  and a bow portion  19 . At the port side portion, a first pivot base  21  has a pair of opposing plates  23  supporting a pivot pin  25 . The pivot pin  25  engages an intermediate member  26  which is pivotally pinned to an end of a sleeve or clamp member  27 . The use of the term clamp or sleeve in truest terms may depend upon whether through bolting, or allan bolting is used. The clamp member  27  has a pair of plates  28  and has an upper end  29  engaging one end of an overall “U” shaped structure  31 . A pin  30  engages the plates  28 . Likewise, at the port side portion, a second pivot base  41  has a pair of opposing plates  43  supporting a pivot pin  45 . The pivot pin  45  engages an intermediate member  46  which is pivotally pinned to an end of a clamp member  47 . The clamp member  47  has a pair of plates  48  and has an upper end  49  engaging one end of an overall “U” shaped structure  31 . A pin  50  engages the plates  48 .  
         [0027]    At the center of the overall “U” shaped structure  31 , a pair of limit fittings including a first fitting  51  and a second fitting  53 , both of which are secured to and fixed with respect to either side of the middle of the overall “U” shaped structure  31 . Between the fittings  51  and  53  a pivoting member  55  includes a first member  57  which is parallel to the structure  31 , and a second member  59  which is spaced apart from the first member  57  and which has an axis generally at a right angle to an axis of the first member  57 . An intermediate member  61  joins the first member  57  to the second member  59 .  
         [0028]    Second member  59  engages a bow, stern, or simply third leg member  63  which is seen extending in a first direction to fit within and engage a pivoting member  65 . The pivoting member  65  may be a storage member as well as a tension member, as will be shown. Pivoting member  65  is usually longer than the clamp members  27  and  47 , and is preferably sized to that the third leg member  63  can slidably fit within it when the two are not joined at a deployed position, such as by a bolt  67  extending through both third leg member  63  and pivoting member  65 . Securing members are referred to as “bolt” even though other joining may be had, especially that which is not as easily seen in the Figures, including allan or hex threaded members. Preferably, bolting will depend upon materials and set up and bolting may not be completely through where materials so permit. Bolt  67  is shown mounted vertically with respect to the view of FIG. 1.  
         [0029]    The other end of pivoting member  65  is pivotally attached to a third pivot base  71  having a pair of opposing plates  73  with the bottom end of the pivoting member  65  joined by a pivot pin  45 . Now, for all three of the lower pivoting members including clamp members  27  and  47  and pivoting member  65 , the pivoting connection can be directly through the members or there may be a protruding plate which fits between the opposing plates  73 . Any number of combinations are possible, the only requirement is that a structure be provided that will enable pivoting and which will also withstand the compression, tension and other forces due to towing a load. Where an insert is to be used, such insert must be fixed within the clamp members  27  and  47  and pivoting member  65  as the case may be. It cannot be overemphasized that the sizes and lengths of all of the components thus far described may vary based upon the size of the boat  11  and the force requirement of the tow.  
         [0030]    Away from the pivoting member  55  in a direction opposite of the main extent of the third leg member  63  is a length of riser  81  terminating at an end  83  having a pinned connection with a pin or bolt  85  as but one example of such a termination. A short length of cable or wire connects with a universal fitting  89  connecting a tow line  91 . The structure which is utilized at the end  83  of the riser  81  can be any structure. The riser  81  provides an additional height, rearward extent, and separation from the “U” shaped structure  31 , and provides several advantages.  
         [0031]    A higher location provides more separation from any possibility of fouling with regard to the second member  59 . A more rearward location takes advantage of the natural slope of the extent of the member  63 , and the length of the riser  81  is not so great as to subject either it or the pivoting member  55  to lateral stress. A bolt  93  is seen extending into the second member  59 , but fixation of the member  63  or the riser  81  can be accomplished by any method. Bolt and nut combinations  95  are shown engaging the fittings  51  and  53 . The adjustable position towing apparatus seen in FIG. 1 is referred to generally as towing support system  101 .  
         [0032]    Referring to FIG. 2, a plan view looking down on the forward portion of the boat seen in FIG. 1, and illustrates that a portion of member  63  of towing system  101  may extend significantly into the pivoting member  65 . A bolt  103  extends out of clamp member  27  and acts to secure one end of overall “U” shaped structure  31 . A bolt  105  extends out of clamp member  47  and acts to secure one end of overall “U” shaped structure  31 . The view of FIG. 2 also illustrates the triangular footing of the towing system  101 .  
         [0033]    [0033]FIG. 3 is a plan view looking into the “U” shaped member  31  with the pivoting member brought level. As can be seen, first and second fittings  51  and  53  are secured to the top center of the overall “U” shaped structure  31  with bolt and nut combinations  95 . First member  57  is mounted to freely rotate with respect to the overall “U” shaped structure  31 , the side to side motion limited by the first and second fittings  51  and  53 .  
         [0034]    The role of the intermediate member  61  in providing separation between the axis of first member  57  and second member  59  is more graphically seen in FIG. 3. A pivot axis of essentially the same is established through the bolts  25  and  45 , as well as another axis through the upper portion of the overall “U” shaped structure  31 , such that both axes can be utilized to somewhat “fold” the towing support system  101  into a position preferably generally parallel to the deck, especially bow portion  19 . The towing system overall “U” shaped structure  31  is seen supported by a flat surface  115 , but the support surface can be slanted, combined with slanted pivot bases  21  and  41  to compensate as needed.  
         [0035]    Referring to FIG. 4, a side view of the “U” shaped member pivotally mounted onto the opposite sides of the deck of the boat seen in FIGS. 1 &amp; 2 is illustrates to emphasize the potential for stowability. The bolt and nut combinations  95  for engaging the first and second fittings  51  and  53  are not shown, for clarity of the side view. The stowage movement shown involves the un-pinning of the pivoting member  65  from the third pivot base  71  by removal of the bolt  75  holding the pivoting member  65  between the opposing plates  73 . Once this is accomplished, the leg member  63  can be brought level to an angle of β with respect to the vertical extent of the overall “U” shaped structure  31 . This position is an interim position and illustrated to show that stowage can occur in either direction. If the vertical extent of the overall “U” shaped structure  31  moves to the right with respect to FIG. 4, the main extent of the leg member will lie close to the flat surface  115  and protrude to the left only a little farther than the pivot bases  21  and  41 . If the vertical extent of the overall “U” shaped structure  31  moves to the left with respect to FIG. 4, the main extent of the leg member will lie forward, extended and close to the flat surface  115 .  
         [0036]    [0036]FIG. 4 illustrates some variations with respect to the earlier Figures, including the presence of a bolt  121  mounted laterally through the third leg member  63  and pivoting member  65 . Further, the second member  59  has an additional bolt  123 . At the end of pivoting member  65 , an insert  125  is seen having an aperture  127  for engaging the bolt  75 .  
         [0037]    In combination with the possibility of folding the towing support system  101 , the pivoting member  65  can be removed, or it can be unbolted, using bolt  121  of FIG. 4, followed by further insertion of the member  63  into the pivoting member  65 , possibly combined with another aperture alignment to enable a stable resulting configuration upon stowing. In the alternative, the pivoting member  65  may remain pinned by bolt  75 , and the bolt  121  may simply be removed, with the pivoting member  65  pivoted to rest flat upon the surface  115 , followed by the placement of the member  63  atop the member  65 .  
         [0038]    [0038]FIG. 5 is a view as seen in FIG. 4, but showing deployment position of the towing support system  101  and to show that pivoting occurs about the horizontal portion of the overall “U” shaped structure  31 . The angle a is the angle which the member  63  achieves with respect to the vertical portion of the overall “U” shaped structure  31 . Where the towing support system  101  is provided for installation, the length of the leg member  63 , as well as the length of the pivoting member  65  can be much longer than needed to enable the user to cut to fit, followed by the through drilling of a hole to accommodate bolt  121 . With this geometry being variable, a user can customize based upon (1) the overall boat decking extent and shape, (2) whether a collapse configuration is possible, in which the collapse can involve removal of the bolt  121  followed by an angular pivoting of the overall “U” shaped structure  31  in the direction of the pivoting member  65  as the end of the member  63  continues to slide into the pivoting member  65 . The lengths and proportions of the towing support system  101  seen in the Figures is not to scale and may vary greatly in actual realization.  
         [0039]    [0039]FIG. 6 is a side view from the same perspectives of FIGS. 4 and 5, but illustrating movement of the towing support system  101  in a folded under configuration illustrating one possible way of movement of de-pinned breakdown in another direction. An angle p shows the movement in the other direction. If the third leg member  63  and pivoting member  65  are of such interfitting length, the direction shown in FIG. 6 could be accomplished without unpinning the bolt  75 , and the assembly could be laid flat with the extended lengthening of the third leg member  63  and pivoting member  65 .  
         [0040]    [0040]FIG. 7 illustrates a closeup of the through bolting of the main leg and the pivot point of the overall “U” shaped member  31 . FIG. 8 is a view looking into the main leg, along lines  8  -  8  of FIG. 7, with a view of the pivot assembly seen in plan position. FIG. 9 is an overhead looking down view, taken along line  9  -  9  of FIG. 8.  
         [0041]    [0041]FIG. 10 is a perspective view of a generalized pivoting member  131  as a one piece or welded set of members joined in a unitary fashion, which can be substituted for first member  57 , second member  59 , intermediate member  61 . Pivoting member  131  has an integrally formed member portion  133 , second member portion  135 , and an intermediate member portion  137 .  
         [0042]    Referring back to FIG. 1, it is clear that the first member  57  could be fitted onto the overall “U” shaped structure  31 , before it is bent into the “U” shape. An alternative construction is shown in FIGS.  11  -  13  and is the preferred construction where bending is to occur before the addition of the first member in an over fitting relationship. Referring to FIG. 11, the overall “U” shaped structure  31  is provided as two halves separated by a short distance as a first angled leg  141  and a second angled leg  143 . First angled leg  141  has an end  145  and second angled leg  143  an end  147 , a gap  149  occurring between the ends  145  and  147 . To secure the gap  149 , an insert  151  is extended into the inside of the ends  145  and  147  of the first and second angled leg  141  and  143 . Also seen are the first and second fittings  51  and  53 , which would be present in any event to prevent lateral displacement along the top of a continuous horizontal length of overall “U” shaped structure  31 . In FIG. 11, apertures  153  which fix the ends  145  and  147  of the first and second angled leg  141  and  143  also set the first and second fittings  51  and  53 .  
         [0043]    Referring to FIG. 12, a view along line  12   12  of FIG. 11 illustrates bolt and nut combinations  95 , which extends through both the insert  151 , the first and second angled legs  141  and  143  near their ends  145  and  147 , and the first and second fittings  51  and  53 .  
         [0044]    Referring to FIG. 13, a view taken along line  13  -  13  of FIG. 12 merely illustrates further detail of the earlier figures, as well as the use of a single aligned bore  157  for placement of the bolt  93  seen in FIG. 1.  
         [0045]    Variations on the structures shown are possible. Referring to FIG. 14, a towing support system  201  has many of the same structural portions seen in FIGS.  1  -  13 , with some variation. The same pivoting footing members are shown, but at the right side of the FIG. 14, plates  28  attach to an inner clamp member  203  which fits within a bottom end  205  of a ninety degree bend tube  207 . A lateral end  209  can accept a fitting  211  to help engage a center pivot tube  213  which is shown in abbreviated length only to accommodate the remainder of the components shown in FIG. 14. Tube  213  can be provided as a long length member, and may even be available to be cut so that the user can customize the system  201  to his needs.  
         [0046]    In system  201 , the overall member most adjacent the third pivot base  71  is a clamp  215  having a first end  217  into which a fore member  219  fits. Fore member  219  is connected to both the third pivot base  71 , and to the clamp  215 . A locking member such as a pin or bolt is used to join aligning apertures  221  and  223 . An upper third leg member  227  has a series of apertures  229  for engagement with an aperture  231  near an end  233  of the fore member  215 . Pre-drilled apertures  229  facilitate the ability of the user to select the lockable displacement of the third leg member  227  within the fore member  215 , and thus select the optimum vertical position of the “U” shaped member formed from the ninety degree bend tube  207  and other components to be described. An end member  235  extends from a second end  237 , opposite a first end  239 . End member  235  includes an extension  241  leading from second end  247  and terminating in an expanded head  243 . This arrangement facilities attachment of a tow line, such as tow line  91 .  
         [0047]    A cross fitting  251  is seen having a first bore  253  and a second bore  255 , having an axis perpendicular to and displaced from the axis of first bore  253 . Second bore  255  fits slidably over the outer diameter of center pivot tube  213 . First bore  253  fits over the outer diameter of the upper third leg member  227 .  
         [0048]    In a mirror fashion, to the left of center pivot tube  213  is seen plates  48  which attach to an inner clamp member  263  which fits within a bottom end  265  of a ninety degree bend tube  267 . A lateral end  269  can accept a fitting  271  to help engage center pivot tube  213 . The ninety degree bend tubes  207  and  267  together with the center pivot tube  213  form the overall “U” shaped structure, similar to structure  31  of FIG. 1.  
         [0049]    Referring to FIG. 15, a perspective view of the components surrounding the cross fitting  251 , illustrates a short bore  275  leading into second bore  255  and a short bore  277  leading into first bore  253 . Short bores  275  and  277  can accommodate threaded members keyed either to the bores  275  and  277  or other structure. Other apertures, such as apertures  273 , may or may not be shown in the structures of FIG. 14 and may or may not be utilized for further structural connectivity, as needed.  
         [0050]    Referring to FIG. 16, a closeup of a footing illustrates that the pivot base  41  can be mounted to a vertical surface as well as a horizontal surface, and still retain the forward and aft direction foldability of the overall “U” shape formed. As can be seen, the plates  48  may have a cross brace  281  and may depend from an insertion plate  283  which is inserted into the inner clamp member  263 . Other variations are possible.  
         [0051]    Although the towing support systems  101  and  201  have been shown with a strong indication of variation in size, lengths and manner of construction of the component parts thereof, the inventive principles illustrated apply to any structure in which deployment and stowage is desired in a structure which has the ability to withstand loads as are created during towing or loading with a line and the like.  
         [0052]    Although the invention has been derived with reference to particular illustrative embodiments thereof, many changes and modifications of the invention may become apparent to those skilled in the art without departing from the spirit and scope of the invention. Therefore, included within the patent warranted hereon are all such changes and modifications as may reasonably and properly be included within the scope of this contribution to the art.