Patent Publication Number: US-2022234686-A1

Title: A variable beam vessel

Description:
TECHNICAL FIELD 
     The present invention relates a variable beam vessel. More particularly, the present invention relates to, but is not limited to, a vessel having a main hull and two floats on opposite sides of the main hull, the floats being retractable towards the main hull. 
     BACKGROUND 
     Catamarans and trimarans have become popular vessels due to their efficient movement through the water, low draft (the vertical distance between the waterline and bottom of the hull) and a wide beam that provides greater stability than a monohull vessel. 
     While the wide beam is useful for stability it can also be problematic for multi-hulled vessels. This is particularly the case for trimarans, which have a central main hull and two floats disposed symmetrically on opposite sides of the main hull. The increased width increases the cost of berthing and makes road travel difficult. 
     Some trimarans have been proposed with retractable stabilizing floats. Some such vessels have floats that pivot aft (i.e. towards the stern), which means they need to incorporate a vertical pivot point at the float. The vertical pivot experiences wear, and is generally considerably weaker than a rigidly fixed arrangement, when faced with consistent loading during use and when transporting the vessel. Other embodiments provide a laterally shifting float arrangement, in which floats that are rigidly fixed to the end of support beams are moved laterally in towards the main hull of the vessel. Such arrangements either lose stability or result in parts of the floats being moved under water that, during normal use, are above the draft level of the floats. Those parts are therefore susceptible to marine growth and degradation. 
     It would be desirable to overcome or alleviate at least one of the above-described problems, or at least to provide a useful alternative. 
     SUMMARY 
     The present disclosure provides a variable beam vessel, comprising:
         a main hull having a longitudinal axis;   a float;   a float connection assembly extending between the float and main hull, the float connection assembly comprising:
           a main support member comprising:
               a float end connected to the float at a float connection; and   a hull end connectable to the main hull; and   
               an actuation system operable to move the float substantially perpendicularly to the longitudinal axis between an in-use configuration in which the main support member is connected to the main hull and maintains the float a first distance from the main hull, and a stowed configuration in which the main support member maintains the float a second distance from the main hull, the second distance being less than the first distance,   wherein the actuation system maintains a common orientation of the float in both the in-use configuration and stowed configuration.   
               

     Unless context dictates otherwise, the “main support member” may be referred to as a support beam. This is not to be confused with the beam of a vessel referring to the width at its widest point when viewing from the bow or stern. 
     The float connection may comprise an abutment formed on a first one of the main support member or the float and located to abut a second one of the main support member and float, to restrict longitudinal relative movement between the main support member and float. 
     The float connection may comprise a slot on one of the main support member and float and a pin on the other of the main support member and float, the pin sliding along the slot between a first position corresponding to the in-use configuration and a second position corresponding to the stowed configuration. The first position and second position may be at opposite ends of the slot. The slot may be shaped to control relative movement of the float and main support member during movement between the in-use configuration and stowed configuration. 
     The float connection may further comprise a pivot, the float pivoting on the float end of the main support member between the stowed configuration and in-use configuration. 
     The pin may be on the float end and the pivot is located distally of the pin. The pin may be one of two pins located on the main support member, and the slot may be one of two slots disposed on opposite sides of the main support member in a channel in the float. The channel may have two opposite end walls and side walls, the end and side walls converging distally of the pivot, each end wall defining a position of the float end of the main support beam when in a respective one of the stowed configuration and in-use configuration. 
     The actuation system may comprise at least two flexible cord lengths each connected at one end to the float and extending from the float to the main hull, and wherein one cord length moves the float connection assembly to the in-use configuration and another cord length moves the float connection assembly to the stowed configuration. The flexible cord lengths may comprise part of the same cord—e.g. a rope fixed to the float at some point intermediate the ends of the rope, with a length of rope extending from either side of the fixed point. 
     The vessel may comprise two floats and two float connection assemblies each connecting a respective one of the floats to the main hull. The actuation systems of the two float connection assemblies may be interconnected such that they can be concurrently operated to move the symmetrically between the in-use configuration and stowed configuration. 
     The hull end of the main support member may be connected to the main hull in the in-use configuration and is disconnected from the main hull in the stowed configuration. 
     The hull end may disconnect from the main hull to facilitate movement to the stowed configuration. The hull end of the main support beam may elevate above the main hull during movement to the stowed configuration, so that it does not obstruct access along the main hull in the stowed configuration. 
     The float connection assembly may be configured to maintain a common draft of the float when in both the in-use configuration and the stowed configuration. 
     The variable beam vessel may further comprise a stabiliser for controlling a position of the main support member relative to the main hull during movement between the in-use configuration and stowed configuration. The stabiliser may comprise a frame extending between the main hull and main support member. The stabiliser may also comprise an alignment member. In such cases, the alignment member and frame maintain a perpendicular alignment between the main support member and longitudinal axis during movement between the stowed configuration and in-use configuration. 
     The main support member may comprise two spaced support beams each having a respective said float end and respective said hull end. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described, by way of non-limiting example, by reference to the drawings, in which: 
         FIG. 1  is a simplified illustration of a variable beam vessel in accordance with present teachings; 
         FIG. 2  is a front perspective view of a vessel in accordance with present teachings; 
         FIG. 3  is a partial close-up view of a float connection assembly, float and main hull of the vessel of  FIG. 2 , in in-use and stowed configurations; 
         FIG. 4  is a close-up cross-sectional view through the float of  FIG. 3 ; 
         FIG. 5  is a partial top perspective view of a float connection used to connect the float to the support beam of the vessel of  FIG. 2 ; 
         FIG. 6  is a schematic illustration of a float and float connection assembly in accordance with present teachings; 
         FIG. 7  is an example of a mechanism for concurrently operating two float actuation systems; 
         FIG. 8  is a simplified alternative embodiment of a float connection assembly, in which the support beam has an elbow joint; and 
         FIG. 9  illustrates an alternative float connection. 
     
    
    
     DETAILED DESCRIPTION 
     Vessels described herein have a variable beam insofar as the overall width of the vessel can be reduced for docking, or increased for stable travel over water. While the description is given generally in the context of trimarans, it will be understood the present teachings can apply similarly to particular configurations of catamaran, and to multi-hulled vessels in general. 
     The term “main hull” is used to identify the hull or buoyant body from which a user operates the floats. The term “float” may therefore refer to a buoyant stabilising body such as an outrigger, but may also refer to a hull that is separate from the main hull. 
       FIG. 1  shows a variable beam vessel  100 . The vessel  100  includes a main hull  102  and two floats  104 ,  106 . Each float  104 ,  106  is spaced from the main hull  102  by a float connection assembly  108 ,  110 . The floats  104 ,  106  thereby provide stability to the main hull  102  against roll. 
     The vessel  100  has an in-use configuration as shown in  FIG. 1 , and a stowed configuration as shown in  FIG. 2 . In the stowed configuration, the floats  104 ,  106  are brought toward the main hull  102 . This narrows the beam of the vessel  100 , making it easier and cheaper to berth. Thus, in the in-use configuration the floats  104 ,  106  are spaced a first distance from the main hull and, in the stowed configuration, are spaced a second distance from the main hull that is less than the first distance. The narrower beam makes navigation through tight marinas easier, and catamarans and trimarans that do not have a variable beam will often take up two berths thereby increasing the cost of berthing. 
       FIG. 3  is a close-up view of a float connection assembly  108  in isolation of the main hull  102 . The float connection assembly extends between the float  104  and main hull  102  (shown in part). The float connection assembly is shown in solid lines in the in-use configuration  114 , and in broken lines in the stowed configuration  116 . 
     The float connection assembly includes a main support member (presently support beam  118 ), and an actuation system  120  as best seen in  FIG. 6 . Operation of the actuation system  120  moves the float  104  between the in-use configuration and stowed configuration. Relative to the longitudinal axis of the main hull (see axis  112  extending directly into  FIG. 1 ), the float  104  moves substantially perpendicularly between the two configurations. 
     The support beam  118  is embodied by a substantially rigid, unbendable member. In the present context, “substantially rigid”, “unbendable” and other terms refer to the support beam and other components being sufficiently rigid or unbendable to achieve the desired function. 
     The support beam  118  has a hull end  120  that is connectable to the main hull, and a float end  122  that is connected to the float  104  at a float connection  124  as shown in  FIGS. 4 and 5 . The float connection  124  includes components of both the float  104  and float end  128  that facilitate controlled relative movement between the float  130  and support beam  126 . 
     The float connection  124 , as shown in  FIG. 5 , includes an abutment  130 . The abutment  130  can take many forms and is presently in the form of a sleeve clamp that attaches to pin  132  and bears against an internal wall  134  of slotted plate  136 . The abutment  130  thereby restricts longitudinal relative movement, in direction X, between the support beam  118  and float  104 . To improve stability of the float  104  on the support beam  118  an opposing sleeve clamp  138  and  140  are provided, that abut against slotted plate  142  to restrict longitudinal movement of the float  104  relative to the support beam  118  in direction Y. 
     It will be appreciated that where an abutment is provided, various arrangements are possible—e.g. the abutment may be on the support beam  118  rather than the float  104 . 
     The following discussion is given with respect to plate  136  and pin  132 , but applies equally to plate  142  and pin  140 . The float connection  124 , particularly slotted plate  136 , comprises a slot  144  on the float  104  and a pin  132  on the support beam  118 . The pin  132  slides along the slot  144  between a first position  146  corresponding to the in-use configuration and a second position  148  corresponding to the stowed configuration. The first position  146  and second position  148  are at opposite ends of the slot  144 . The trajectory of relative movement between the float  104  and float end  128  of the support beam  118  is controlled by the shape of the slot  144 . 
     To improve stability, the float connection  124  also includes a pivot  150 . The pivot  150  is provided at the float end  128  of the support beam  118 , such that relative movement between the float  104  and support beam  118  is limited to rotational or pivotal movement of the float  104  on the float end  128  of the support beam  118 . The pivot  150  is located distally of the pin  132 . The slot  144  is arc-shaped corresponding to a trajectory of the pin  132  about a radius of curvature centred at the pivot  150 . The pivot  150  therefore is a fixed point at which relative movement is purely rotational whereas, at the pin, relative movement comprises a translation movement. 
     The pins  132 ,  140  and respective slots  144 ,  152  are disposed on opposite sides of the float end  128  of the support beam  118 . Therefore, the float connection  124  comprising the pins  132 ,  140  and slots  144 ,  152  both controls relative movement between the float  104  and support beam  118  and inhibits undesirable movements between the two. 
     The float end  128  is located in a channel  154  of the float  104 . As shown in  FIGS. 4 and 5 , the channel  154  comprises two opposite end walls  156 ,  158  and two side walls  160 . The side walls  160  of the present embodiment are formed by slotted plates  136 ,  142 . The end walls  156 ,  158  and side walls  160  converge distally of the pivot  150 . The region at which the walls  156 ,  158 ,  160  converge is rounded and the float end  128  of the support beam  118  fits snugly within the rounded region. 
     Each end wall  156 ,  158  defines a position of the float end  128  of the support beam  118  when in a respective one of the stowed configuration and in-use configuration. End wall  156  defines the location of the float end  128  when in the in-use configuration as shown in  FIG. 4 , and end wall  158  defines the location of the float end  128  when in the stowed configuration. Presently, the float end  128  has a slight curve and thus end wall  156  is slightly convex tightly cooperate (i.e. abut) the concave side  162  of the float end  128 , and end wall  158  is slightly concave to cooperate with the convex side  164  of the float end  128 . 
     The float connection may take other forms. For example, the float connection  200  in  FIG. 9  may connect float  202  to support beam  204 , in which the same pin and slotted plate configuration is provided, with the slotted plates  206 ,  208  being provided on internal sides of a channel  210  in the support beam  204 , and the pins on the float. All such variations are intended to fall within the scope of the present disclosure. 
     Controlling relative movement ensures the float is consistently positioned in the in-use configuration which, when similarly performed for the opposite float  106 , ensures proper balancing of the vessel  100 . Similarly, inhibiting undesirable movements reduces the potential for damage resulting from repeated impact loads of swells and water movements during use. 
     The float connection  124  described above helps to ensure that the float  104  maintains a common orientation in both the in-use configuration and stowed configuration. This means that if the float  104  is vertical in the in-use configuration, it will have the same orientation, and thus be vertical, in the stowed configuration. Moreover, by controlling a height of the support beam  118  as described below, the float connection assembly  108  maintains a common draft of the float  104  when in both the in-use configuration and the stowed configuration. 
     By maintaining a common draft, the portion of the float  104  that is below the waterline in use is substantially the same as the portion of the float  104  below the waterline when stowed. Anti-fouling paint need only be applied up to the height of the draft of the float  104  in the in-use configuration, yet that is sufficient to substantially inhibit marine growth over the float  104  when in the stowed configuration, since the same portion of the float  104  is submerged in each case. 
     The actuation system  120  similarly ensures the float  104  is maintained in a consistent orientation in both the in-use and stowed configurations. It does so by controlling relative movement, or rotation, of the float  104  relative to the support beam  118 . With reference to  FIG. 6 , the actuation system  120  comprises two flexible cord lengths (presently embodied by ropes  162 ,  164 ) (though in some embodiments there may be more than two) each of which is connected at one end to the float  104 . The ropes  162 ,  164  extend from the float  104  to the main hull  102 . 
     One rope  162  moves the float connection assembly  108  to the in-use configuration and the other rope  164  moves the float connection assembly  108  to the stowed configuration. The rope  162 ,  164  are operated by applying tension to one rope  162  at a time  164 . For example, pulling rope  162  will result in contraction of the float connection assembly  108 , and rotation of the float  104  on the support beam  118 , to the stowed configuration. Conversely, pulling rope  164  will result in extension of the float connection assembly  108 , and rotation of the float  104  on the support beam  118 , to the in-use configuration. 
     Rope  162  passes around or through guide pulleys  166 ,  170  and can be accessible from the main hull  102 . In an embodiment, the rope  162  is connected to the halyard (not shown) on the mast. In other embodiments, the rope  162  is independent of the halyard (e.g. is a dedicated rope or line)—the independent rope  162  may be connected to the mast or at another appropriate position. Rope  164  passes around pulleys  172 ,  166 ,  170  to also be accessible from the main hull  102  for operation. In an embodiment, the rope  164  is connected to the reacher winch (not shown). In another embodiment, the rope is independent of the reacher. The operation of the ropes will be understood from  FIG. 6 . 
     In some embodiments, the ropes or cord lengths are a single length fixed at to the float at a common point—e.g. at point C and passing through eyelets  174 ,  176  shown in broken lines, but otherwise having the same path as rope  164 . 
     While the present teachings can be used on a vessel having a single float, or a dual-hull vessel, the present vessel  100  comprises two floats  104 ,  106 . The actuation systems of the two corresponding float assemblies  108 ,  110  may be interconnected—e.g. form a common length of rope—so that operation of the actuation system of one float assembly concurrently actuates the actuation system of the other float assembly. For example, as shown in  FIG. 7 , operation of winch  178  will result in both ropes  180 ,  182  either being wound around the winch drum or wound off the winch drum. Concurrent actuation of both float assemblies assists in maintaining balance of the vessel  100  during movement between the in-use and stowed configurations. 
     In some embodiments, the float  184  may be connected to the main hull  186  by an elbow beam  188 . This would allow both the float end of the elbow beam  188  to remain connected to the float and the hull end to remain connected to the hull, during movement between configurations. However, this can produce a point of weakness in the middle of the support beam, and makes the use of trampolines more difficult. 
     In the embodiment shown in  FIGS. 1 to 6 , the hull end  120  is connected to the main hull  102  in the in-use configuration and is disconnected from the main hull  102  when stowed. If the hull end  120  remains attached to the main hull  102 , the support beam  118  cannot move to allow the vessel to attain the stowed configuration. 
     When in the in-use configuration, an angle section  194  at the hull end  120  is seated on a plate  196  on the main hull  102  as shown in  FIG. 3 . The hull end  120  may be fixed in position against the plate using any appropriate mechanism—e.g. the angle section  194  may be bolted to the plate  196  in the in-use configuration. 
     As shown in  FIGS. 2 and 3 , the hull ends  120  of the support beams  118  elevate above the main hull  102  during movement to the stowed configuration. This avoids the support beams  118  extending across the deck of the main hull  102 , which would otherwise obstruct access along the main hull  102  when in the stowed configuration. 
     To ensure the trajectory of the support beam  118  is controlled and consistent, the float connection assembly also includes a stabiliser (see  FIG. 3 ) for controlling the position of the support beam  118  relative to the main hull  102  during movement between the in-use configuration and stowed configuration. The stabiliser can take many forms. Presently, the stabiliser includes a frame  184  extending between the main hull  102  and support beam  118 . The frame  184  is a rigid member of fixed length, pivotally connected at its opposite ends to the support beam  118  and main hull  102 . The frame has two lateral struts  186  as shown in  FIG. 2 , attached on opposite sides to the support beam  118 . 
     To reduce pivoting of the support beam  118  about the longitudinal axis of the frame  184 , the stabiliser also includes an alignment member  188 . The alignment member  188  and frame  184  fixed the direction of a length of the support beam  118  and thereby the support beam  118  as a whole, owing to its rigidity. The alignment member  188  and frame  184  thereby maintain a perpendicular alignment between the support beam  118  and longitudinal axis  112 —i.e. the support beam  118  moves in a plane for which the axis  112  is a normal—during movement between the stowed configuration and in-use configuration. 
     When in the in-use configuration, the alignment member  188  is received in a slot  192  in the support beam  118 . 
     To further improve stability, the main support member comprises two spaced support beams  118 ,  190  as shown in  FIG. 2 . Each support beam  188 ,  190  has a respective float end and hull end that operates as described above. Again, the actuation system may concurrently operate both support beams, or all four support beams for a trimaran vessel, to maintain stability during transition between in-use and stowed configurations. 
     It will be appreciated that many further modifications and permutations of various aspects of the described embodiments are possible. Accordingly, the described aspects are intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims. 
     Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 
     The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.