US20250026446A1

US20250026446A1 - Multihull Vessel Side Hull Retraction System

Info

Publication number: US20250026446A1
Application number: US18/776,307
Authority: US
Inventors: Levi Catton; Torsten Lau
Original assignee: Leidos Inc
Current assignee: Leidos Inc
Priority date: 2023-07-20
Filing date: 2024-07-18
Publication date: 2025-01-23

Abstract

A multihull vessel includes four main beam assemblies connected a central hull with two outer hulls and a deployment/retraction system which operates on the principle of converting transverse width of the beams into the longitudinal dimension, within the overall length of the vessel. An overall length of the multihull vessel is approximately the same when the four main beam assemblies are deployed and when four main beam assemblies are retracted.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to U.S. Provisional Patent Application No. 63/514,581 entitled MULTIHULL VESSEL SIDE HULL RETRACTION SYSTEM, filed Jul. 20, 2023, which is incorporated herein by reference in its entirety.

BACKGROUND

Technical Field

The technical field is generally related to retractable multihull vessels and more particularly to an improved multihull retraction design.

Description of Related Art

There are a three main existing methodologies used to solve the multihull transverse retraction problem. The Farrier trimaran folding system was designed and patented by multihull designer Ian Farrier in the 1970s, and is used on Farrier and Corsair classes of recreational trimarans. The system has been progressively refined since the 1970s and is mature, practical and well-proven across many builds. The system uses longitudinal rotation axes which translate width into height during the retraction, which limits the amount of extended width that can practically be achieved, and rotates the side hulls into a canted orientation, which is undesirable in some circumstances.
The swing-arm trimaran retraction system, used by Dragonfly classes of recreational trimarans, and in a number of custom trimarans since the 1970s has been progressively refined since the 1970s and is mature, practical and well-proven across many builds. The system uses vertical rotation axes to translate width into length, resulting in an increase in overall length of the vessel in the retracted position, approximately equal to the reduction in the half-beam dimension.
The sliding boom-sleeve retraction system, used in a range of trimaran designs uses transverse horizontal tubular sleeves fixed in the center structure (center hull or center pod) with booms which slide transversely inside the sleeves.
There are also other less commonly used, or theorized, folding and retraction systems based on different geometric principles, but there remains a need in the art for a system and method for retraction of side hulls to reduce the overall beam of the vessel between the extended and retracted positions.

SUMMARY OF EMBODIMENTS

The embodiments herein provide a system and method for trimaran and center pod catamaran vessels' side hulls to be transversely retracted, to reduce the overall beam of the vessel between the extended and retracted positions. This enables wide multihull vessels to be retracted to a reduced overall beam, which provides a number of practical benefits including reduced storage size, improved ability to berth in marina berths, improved ability to launch over public boat ramps, road transportation by trailer within legal load width limits, transportation in ISO shipping containers, and recovery to parent vessel stowage locations that don't support stowage of the vessel's full beam dimension.
In an exemplary embodiment, a multihull vessel includes: a center hull; a first pair of deployable and retractable beam assemblies on a first side of the center hull and a second pair of deployable and retractable beam assemblies on a second side of the center hull; a first deployment and retraction system connected to the center hull and to the first pair of deployable and retractable beam assemblies and a second deployment and retraction system connected to the center hull and to the second pair of deployable and retractable beam assemblies; a first outer hull connected to the first pair of deployable and retractable beam assemblies and a second outer hull connected to the second pair of deployable and retractable beam assemblies, wherein an overall length of the multihull vessel is approximately the same when the first and second pair of deployable and retractable beam assemblies are deployed and when the first and second pair of deployable and retractable beam assemblies are retracted.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will be better understood from the following detailed description with reference to the drawings, in which:

FIG. 1 is a rendered view of a multihull vessel in fully extended (deployed) hull position;

FIGS. 2A and 2B are rendered isometric views of a fully extended beam assembly in accordance with an embodiment herein;

FIG. 3 is a schematic plan view of a fully extended, dual boom beam assembly on a starboard side of a multihull vessel in accordance with an embodiment herein;

FIGS. 4A and 4B are schematic views of a fully extended single boom in accordance with an embodiment herein;

FIG. 5 is a rendered view of a multihull vessel in fully retracted hull position;

FIGS. 6A and 6B are rendered isometric views of a fully retracted beam assembly in accordance with an embodiment herein;

FIGS. 7A and 7B are schematic views of a fully retracted single boom in accordance with an embodiment herein;

FIGS. 8A, 8B, 8C, 8D, 8E, and 8F are schematic views, including cross-sectional and expanded views, of a top wishbone beam in accordance with an embodiment herein;

FIGS. 9A, 9B, 9C and 9D are schematic views, including expanded views, of a bottom wishbone beam in accordance with an embodiment herein;

FIGS. 10A, 10B, 10C, 10D and 10E are schematic views, including an isometric, cross-sectional view of a top wishbone including bracket plate cross-sectional views of top and bottom wishbone fastening brackets in accordance with an embodiment herein;

FIGS. 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H and 11I are schematic views, including cross-sectional views and expanded views, of a boom in accordance with an embodiment herein;

FIGS. 12A, 12B and 12C are schematic views, including a cross section view, of a boom portion connected to a movable car in accordance with an embodiment herein;

FIGS. 13A, 13B and 13C are schematic views of portions, including a cross-sectional view, of a top and bottom wishbone plates and bracketed to a single boom in accordance with an embodiment herein;

FIGS. 14A, 14B and 14C are schematic views of portions, including a cross-sectional view, of a boom and bracketed to an ama in accordance with an embodiment herein; and

FIGS. 15A and 15B are rendered isometric views showing a fully retracted multihull vessel on a support frame (FIG. 15A) which can be carried by a trailer (FIG. 15B) in accordance with an embodiment herein.

DETAILED DESCRIPTION

FIG. 1 is a rendered isometric view of a multihull vessel 1 in fully extended (deployed) hull position in accordance with an embodiment herein. The vessel 1 includes four main beam assemblies (forward 12 a ₁and aft 12 b ₁, port (not shown) and starboard (not shown)) connecting center hull 5 to ama 10 a and 10 b. One skilled in the art will appreciate that forward 12 a ₁and aft 12 b ₁beam assemblies are identical, and the port and starboard assemblies are identically symmetrical. A deployment/retraction system operates on the principle of converting transverse width of the beams into the longitudinal dimension, within the overall length of the vessel 1.
Each beam assembly 12 a ₁and 12 b ₁includes the following key elements: boom 14 a ₁and 14 b ₁; boom inboard pivot pin assembly (FIG. 12C); boom outboard board pivot pin assembly (FIG. 12C); upper wishbone beam 16 a ₁and 16 b ₁; lower wishbone beam 16 a ₂and 16 b ₂; upper wishbone beam inboard pivot assembly (FIG. 10D); lower wishbone beam inboard pivot assembly (FIG. 10E); and boom-wishbone pivot pin assembly (FIG. 13C). The beam assemblies 12 a ₁and 12 b ₁are further attached to car 25 a; car track 18 a ₁and 18 b ₁. As shown in FIGS. 2A and 2B, each forward and aft pair of beam assemblies 12 a ₁and 12 b ₁is coupled together on a retraction drive system on each side of central hull 5. This drive system consists of: retraction line loop rigging assembly 15, including pulleys 19 a and 19 b, and retraction line winch 17. As will be appreciated by one skilled in the art, the winch could be manual-mechanical, electro-mechanical, or hydraulic depending on the size of the vessel and the amount of retraction force required. A more detailed description of these and other elements is presented below.
Although not critical to operation of hull deployment and retraction which is the focus of the embodiments herein, additional features of the exemplary multihull vessel 1 of FIG. 1 include: solar panels 6, a navigation radar 7, a pole mast for sensors and communication equipment 8, and retractable rigid wing sails 9.
FIGS. 2A and 2B provide rendered isometric views of a fully extended beam assemblies 12 a ₁and 12 b ₁. Similarly, FIG. 3 provides a plan view of a partial vessel showing fully extended beam assemblies 12 a ₁and 12 b ₁connecting central hull 5 to ama 10 a. FIGS. 4A and 4B include additional features of extended beam assembly 12 a ₁including: top and bottom wishbone bracket plates 26 a ₁and 26 a ₂which connect the top and bottom wishbone beams 16 a ₁and 16 b ₁to center hull 5 (not shown); boom landing 28 a between at the ama 10 a end of boom 14 a ₁; and boom reinforcement top double plate 20 a ₁, boom doubler plate 22 a ₁and boom end plate 24 a ₁.
FIG. 5 is a rendered isometric view of a multihull vessel 1 in fully retracted hull position. FIGS. 6A and 6B provide rendered isometric views of a fully retracted beam assemblies 12 a ₁and 12 b ₁. FIGS. 7A and 7B include the additional features of retracted beam assembly 12 a ₁as described with respect to FIGS. 4A and 4B.
FIGS. 8A, 8B, 8C, 8D, 8E, and 8F are schematic views, including cross-sectional and expanded views, of a top wishbone beam 16 a ₁which includes top and bottom plates 16 a _{1(TOP PLATE)}, 16 a _{1(BOTTOM PLATE)}, multiple cap plates 16 a _{1(CAP PLATE #1)}, 16 a _{1(CAP PLATE #2)}, wishbone bosses 30 a ₁and wishbone T-section 31 a ₁. Similarly, FIGS. 9A, 9B, 9C and 9D are schematic views, including expanded views, of a bottom wishbone beam 16 a ₂which includes top and bottom plates 16 a _{2(TOP PLATE)}, 16 a _{2(BOTTOM PLATE)}. Cross-sectional view and features for the bottom wishbone beam are identical to those of the top wishbone beam.
FIGS. 10A, 10B and 10C are schematic views, including an isometric, cross-sectional view of a top wishbone beam 16 a ₁including bracket plate 26 a ₁. FIGS. 10D and 10E are cross-sectional views of the top and bottom wishbone fastening brackets and include: nut 9 and bolt 7, flat washers 11, acetal bush 13 and washer 15, wishbone boss 30 a ₁or 30 a ₂, bracket plate 26 a ₁or 26 a ₂and wishbone beam 16 a ₁or 16 a ₂.
FIGS. 11A, 11B, 11C, 11D, 11E, 11F, 11G, 11H and 11I are schematic views, including cross-sectional views and expanded views, of a boom 14 a ₁. FIG. 11A is a plan view of boom 14 a showing top boom plate 14 a ₁, a first boom end plate 24 a ₁, boom ama boss 21, boom wishbone boss 27, boom reinforcement top double plate 20 a ₁, boom cap plate 23 a ₁and boom doubler plate 22 a ₁. FIG. 11B is a profile view of boom 14 a showing features of FIG. 11A plus additional features including bottom boom plate 14 a ₂, a first boom end plate 24 a ₂, boom reinforcement bottom double plate 20 a ₂, and bottom boom doubler plate 22 a ₂. FIGS. 11C, 11D, 11E, 11F, and 11G are cross-sectional views along identified portions of boom 14 a with an additional feature of boom T section 32. Finally, FIG. 11H and FIG. 11I are expanded plan views of top boom plate 14 a ₁and bottom boom plate 14 a ₂.
FIGS. 12A and 12B are schematic views of a boom 14 a portion connected to a movable car 25 a as viewed from bow (FIG. 12A) and stern (FIG. 12B). Additional features not previously described include boom connector 36 and connector pin 38. FIG. 12C is a cross-sectional view of the boom 14 a to car 25 a fastening mechanism and includes: nut 9 and bolt 7, flat washers 11, acetal bushes 13 and washers 15, mast track 18 a and boom connector 36.
FIGS. 13A and 13B are schematic views of portions of a top and bottom wishbone bracketed to a single boom as viewed from stern (FIG. 13A) and bow (FIG. 13B). FIG. 13C is a cross-sectional view of wishbone 16 a, 16 b to boom 14 a ₁, 14 a ₂fastening mechanism and includes: nut 9 and bolt 7, flat washers 11, acetal bushes 13, boom reinforcement top and bottom double plates 20 a ₁, 20 a ₂and wishbone bosses 30 a ₁or 30 a ₂.
FIGS. 14A and 14B are schematic views of portions of boom 14 a bracketed to ama 10 a. FIG. 14C is cross-sectional view of the boom 14 a fastened to the ama 10 a. The fastening mechanism includes: nut 9, flat washers 11, acetal bushes 13, boom ama boss 21 and ama pivot pin 40.
A retraced vehicle 1 may be carried on a support frame 45 and trailer 50 as shown in FIGS. 15A and 15B.
Accordingly, as shown in detail in the figures and discussed above, each of the four booms 14 is mounted to a pivot pin 40 at the outboard end, with the outboard pivot pin 40 being fixed to one of the two ama (side hulls) (FIGS. 14A-14C). The inboard end of each boom is mounted to a pivot point which is in turn mounted to a batten car assembly (FIGS. 12A-12C). The batten car assembly slides along a track 18 mounted longitudinally on the side of the center hull 5. This arrangement allows the inboard end of each boom 14 to slide forwards and aft, as well as for each boom 14 to pivot in the retraction plane.
Each of the four booms 14 is further supported by a wishbone beam arrangement 16. The wishbone beam arrangements in the preferred embodiment are comprised of separate upper (top) and lower (bottom) wishbone beams, 16 a, 16 b, as shown and described above. Alternatively, the upper and lower wishbone beams may be structurally connected as one wishbone or V-shaped part. The wishbone beams are angled out of the retraction plane so that the wishbone beams and the main boom to which they are connected form a triangular truss in the transverse plane. The outboard end of the wishbone beams are fixed to the boom at the boom-wishbone pivot pin assembly, which is located at approximately the mid-point of the main boom (FIGS. 13A-13C). The exact location of this pivot point helps to determine the exact geometry of the retraction movement. The inboard ends of the wishbone beams are fixed to pivot points on the side of the center hull 5 (FIGS. 10A-10E).
As shown in at least FIGS. 2A and 2B, the forward and aft batten car assemblies are tied into a line loop made from a suitable high performance low stretch fiber such as Dyneema which passes around two return pulleys 19 a, 19 b, located aft of the aft end of the aft batten car track 18 b, and forward of the forward end of the forward batten car 18 b track respectively. A winch mechanism 17 pulls the line in both directions. The winch driving the line loop pulls the batten cars aft to move the side hulls into the extended position, and forward to move the side hulls into the retracted position.
As mentioned above and as will be appreciated by one skilled in the art, the forward and aft beam assemblies are identical, and the port and starboard assemblies are identically symmetrical. Each beam assembly operates in a common retraction plane which is in or near the horizontal plane (and symmetrical port and starboard if not exactly horizontal). The retraction plane may be canted above or below the horizontal plane in order for the retraction movement to move the side hulls either up or down with respect to their extended position, in order to vertically locate the side hulls with respect to the center hull in the desired vertical position when retracted. All pivot pins are perpendicular to the retraction plane.
The retraction system and method described herein provides numerous main advantages over existing retraction designs. First, the retraction occurs within the overall length of the vessel. There is no change in longitudinal position of the side hulls, and therefore the side hull length is maximized within both the extended and retracted overall length dimensions. Put another way, there is no increase in length in the retracted position, as there is for current swing-arm multi-hulls. This results in savings in berthing and storage costs and improves transportability. Second, the geometry is very efficient in converting overall width of the main beams in extended position into the longitudinal orientation in the retracted position. This provides a very high retraction ratio (ratio of extended overall beam to retracted overall beam), with retraction ratios of 6:1 or more potentially possible, meaning that vessels with relatively high extended beam (e.g. length to beam ratios of 1:1) can be retracted to beams similar to an equivalent length monohull. This ability to provide very high overall beam in extended position provides major performance advantages for sailing multihulls. Third, there is no change in orientation of the side hull. This means that the vessel continues to benefit from the stability effect of the side hulls in the water, without the side hull waterlines changing orientation. This prevents fouling and discoloration from occurring on the outboard side of the side hulls in the retracted position, as can occur for current Farrier-style folding systems.

Claims

We claim:

1. A multihull vessel, comprising:

a center hull;

a first pair of deployable and retractable beam assemblies on a first side of the center hull and a second pair of deployable and retractable beam assemblies on a second side of the center hull;

a first deployment and retraction system connected to the center hull and to the first pair of deployable and retractable beam assemblies and a second deployment and retraction system connected to the center hull and to the second pair of deployable and retractable beam assemblies;

a first outer hull connected to the first pair of deployable and retractable beam assemblies and a second outer hull connected to the second pair of deployable and retractable beam assemblies,

wherein an overall length of the multihull vessel is approximately the same when the first and second pair of deployable and retractable beam assemblies are deployed and when the first and second pair of deployable and retractable beam assemblies are retracted.

2. The multihull vessel of claim 1, wherein each deployable and retractable beam assembly includes a boom and a top wishbone beam connected to the boom at a first end to a top pivot point and a bottom wishbone beam connected to the boom at a first end at a bottom pivot point.

3. The multihull vessel of claim 2, wherein the top and bottom pivot points are located at an approximate midpoint of the boom length.

4. The multihull vessel of claim 3, wherein the top and bottom pivot points are pivot pin assemblies.

5. The multihull vessel of claim 2, wherein the top wishbone beam is connected at a second end thereof to the center hull at a pivot point and the bottom wishbone beam is connected at a second end thereof to the center hull at a pivot point.

6. The multihull vessel of claim 5, wherein each pivot point is a pivot pin assembly.

7. The multihull vessel of claim 2, wherein each boom is connected at a first end thereof to a first or second outer hull at a pivot point and is connected at a second end thereof to a first or second deployment and retraction system.

8. The multihull vessel of claim 7, wherein the pivot point is a pivot pin assembly.

9. The multihull vessel of claim 7, wherein each of the first and second deployment and retraction systems includes a pair of movable cars, a pair of tracks, a loop rigging assembly, a pulley system and a winch.

10. The multihull vessel of claim 9, wherein a second end of each boom is connected to a movable car.

11. The multihull vessel of claim 9, wherein the winch is selected from the group consisting of a manual-mechanical winch, an electro-mechanical winch, and a hydraulic winch.