Patent Abstract:
This invention relates to a naval rescue vessel, comprising a propulsion unit ( 1 ) powered by a water jet and a hull unit ( 200 ), wherein said hull unit is at least partly flexible and wherein said propulsion unit ( 100 ) is arranged to form a rigid unit, and wherein the two units ( 100, 200 ) are interconnected to form a naval rescue vessel intended to be handled/maneuvered by a single rescuer, wherein the interconnection ( 130, 205 ) between the two units ( 100, 200 ) is arranged to provide a releasable connection of the units.

Full Description:
TECHNICAL FIELD 
     This invention relates to a naval rescue vessel, comprising a propulsion unit powered by a water jet and a hull unit, wherein said hull unit is at least partly flexible and wherein said propulsion unit is arranged to form a rigid unit, and wherein the two units are interconnected to form a naval rescue vessel intended to be handled/maneuvered by a single rescuer. 
     BACKGROUND AND PRIOR ART 
     Numerous different kind of naval rescue vessels are known for the purpose of rescuing people from drowning. For instance there exist numerous different kind of rescue boats of many different designs, using some kind of conventional propulsion. A general disadvantage with traditional boats is that they are relatively wide/large applying difficulty in coming close to the individual in need and/or difficulty in getting the individual on to the boat. Smaller naval rescue vessels do exist but they all have some kind of inferior stability, inferior loadability, inferior controllability and/or inferior propulsion power/power capability. It has been suggested to use a water scooter (small water jet vessel) to in a modified manner to create naval rescue vessel that could better fulfil existing needs, but up to now no such design has been made available. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a design of a naval rescue vessel that may combine the advantages concerning versatility regarding a water scooter with design features suited for rescuing individuals in emergency situations in water, e.g. from drowning, which in accordance with the solution defined in the appended claims provides drastic synergetic results. 
     Thanks to the invention there is presented a new naval rescue vessel providing a great number of important advantages regarding saving PIW (person in water), e.g.:
         separate hull unit that may easily be exchanged, e.g. due to wear or damage,   a design that allows for integrated portions providing a fender function,   easy snap-in interconnection concept, which “automatically” provides exact positioning,   a design that facilitates self-bailing between the two units,   a rescue vessel that may easily be transported by means of helicopter, also at very high speeds,   a design that allows to be toed at high speed,   a design that may withstand tough conditions, e.g. to run ashore, that may lift the vessel to ride on top of big waves, that can withstand hard hits (e.g. touching a rock), etc.       

     Further advantages regarding preferred features of the invention will be presented in connection with the description of the preferred embodiment below. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       In the following the invention will be described more in detail with reference to the enclosed drawings, wherein: 
         FIG. 1  shows a perspective view from above and behind of a vessel of a preferred embodiment according to the invention, having some of the upper portions cut away, 
         FIG. 2  shows a hull unit of the vessel shown in  FIG. 1 , 
         FIG. 3  shows a propulsion unit in a perspective view seen from behind and above of the vessel shown in  FIG. 1 , 
         FIG. 4  shows a cross-sectional view along line IV-IV in  FIG. 2 , 
         FIG. 5  shows a cross-sectional view along line V-V in  FIG. 2 , 
         FIG. 6  shows a cross-sectional view along line VI-VI in  FIG. 3 , 
         FIG. 7  shows a cross-sectional view along line VII-VII in  FIG. 3 , and, 
         FIG. 8  shows a perspective view of an electrical control unit in accordance with a preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1  there is shown a perspective view from above and behind of essential portions of a hull unit  200  and a propulsion unit  100 , in an assembled mode of the invention. The units  100 ,  200  are interlocked to form a naval rescue vessel. In the propulsion unit  100 , presented with the top portion cut away, there is an inner space  150  for a water jet propulsion unit (not shown). The bottom of the propulsion unit  100  is arranged with numerous support devices, e.g.  151 ,  152 ,  153 , onto which the propulsion unit is securely fixed. At the front of the propulsion unit  100  there is a drivers area  103 , onto which, and in proximity to which, necessary control devices for propulsion of the vessel  100 ,  200  are/will be attached (not shown). The driver/rescuer will have his feet onto foot rest areas  202  formed in the hull unit  200 . Adjacent the rear end of the propulsion unit  100  there is an opening  154  facilitate easy cleaning of the water jet (not shown). Preferably a water jet propulsion, a steering mechanism, control devices, etc. are used that exist for other water scooters, to take advantage of cost efficiency resulting from large scale production. 
     The hull unit  200  comprises a central portion  200 A having a side/fender-portion  200 B,  200 C attached thereto on each side. All portions  200 A,  200 B,  200 C of the hull unit  200  are produced in a flexible and resilient material, preferably polyethylene, and in such a manner that each portion  200 A,  200 B,  200 C forms a sealed hollow inner space, preferably mainly (or indeed totally) filled with air. The sealed volume of all three units  200 A- 200 C amount to about 800 dm 3 , preferably in the range 500-1000 dm 3  providing extra safe buoyancy, since the three portions are sealed individually. Because each portion is produced in a resilient polymer, e.g. polyethylene, it provides extra safety, due to the fact that such a material will not be punctured even if hit by hard objects. Further, such a material is easily repaired by the use of conventional methods. Especially considering that the three different portions are individually sealed extra safety is provided since even if one of the portions would be punctured the remaining two would still provide sufficient buoyancy to enable safe manoeuvring and propulsion of the water scooter. It is understood that depending on the purpose and need of the vessel the total buoyancy needed may vary. Preferably the total buoyancy will be in the range of 1000 dm-1800 dm 3 , more preferred 1200 dm-1600 dm 3 . The amount of buoyancy is preferably divided among the three portions in such a manner that the side portions  200 B,  200 C are equally sized and in total would amount to about 10-40% of the total volume, preferably 20%-30%. Moreover the buoyancy is divided in the hull portion  200  in such a manner that the front will have a large amount of buoyancy, to give the vessel the ability to “ride on top of waves”. The remaining volume is located in the central portion  200 A. As mentioned a preferred kind of material to be used is a tough kind of polymer (such as polyethylene), which is preferably also weldable, due to the fact that preferably the side portions  200 B,  200 C are welded onto the central portion  200 A to thereby safely and securely fix them. Preferably each portion is rotation moulded. The thickness of the enclosing barrier layer is thereby easily adapted by the amount of polymer that is supplied into the mould. Preferably the thickness of the sealing encasing is in the range of 2-10 mm, preferably 4-7 mm. In a preferred embodiment the thickness of the central portion  200 A is larger than the thickness of the side portions  200 B,  200 C, e.g. about 7 mm in the central portion  200 A and about 4 mm in the side portions  200 B,  200 C. 
     In  FIG. 2  there is shown a view from above of the hull unit  200 . As can be seen the central portion  200 A is substantially wider than each one of the side portions  200 B,  200 C. Moreover it is shown that each side portion  200 B,  200 C extends along the outer periphery of the central portion  200 A from the front along the periphery of each side and around the rear corner. The rear ends  204  of the side portions  200 B,  200 C are positioned to leave a substantial gap between them at the rear of the vessel, providing space for the water jet in the propulsion unit  100 . The central portion  200 A is arranged with a number of edges  205 ,  207 ,  209 ,  211  positioned stepwise from the rear end, in a direction towards the centre, to form a stepwise narrowing open space  220  adapted to the configuration of the propulsion unit  100 . This space  220  opens up into the rear end bottom area  215 ,  216 ,  250  of the central portion  200 A. The configuration of the upper surfaces  215 ,  216  of the bottom area is shaped to correspond to the shape of the corresponding outer surfaces of the propulsion unit  100  to provide contact between the propulsion unit  100  and the upper bottom surfaces  215 ,  216  of the central portion  200 A, thereby providing for stability/rigidity of the vessel. 
     As shown in  FIG. 4  there is sealed space  218 B between the upper surfaces, e.g.  215 ,  216  and the lower surfaces, to provide buoyancy. At the front of the central portion  200 A there is provided a top deck surface  219 , which forms the upper sealing layer of the central portion  200 A and which together with the design of the front of the central portion  200 A encloses a substantial portion of the totally enclosed volume  218 A,  218 B of the central portion  200 A. Preferably the enclosed volume  218 A within this portion of the central portion  200 A is in the range of 40%-70% of the total volume within the central portion  200 A, preferably more than 50% (see also  FIG. 4 ), to provide a sufficient amount of buoyancy to allow the vessel to be lifted up in the water also when hitting large waves, i.e. to not risk to have the vessel diving into big waves. Moreover there is an advantage in that design also from the aspect of being able to use the vessel to run ashore, or to be able to hit the hard object. The flexible, resilient material of the front wall  21 , in combination with the large enclosed “gas volume”  218 A provides for good resiliency which enables the vessel to withstand hitting hard objects, e.g. in conjunction with running ashore. In the transition area between the bottom surfaces  215 ,  216  and the front there is provided a delimited space formed by forwardly converging side walls  212 . As can be seen in  FIG. 4  this delimited space is at its front wall arranged with a through hole  213 ,  217 . Further,  FIGS. 2 and 4  present that there is a transition area  203  along each side of the central portion  200 A, which transition area joins the bottom are  215 ,  216  with the side walls. At the upper termination of this side wall  203  there is positioned an interlocking device  230  that extends all the way from the area of the most rearward edge  205  on one side to the other one of the other side. 
     In  FIGS. 4 and 5  there is shown that the interlocking device  230  is in the shape of recess having a bottom wall  232 , a side wall  231  and a top wall  233 . The width w of the recess, i.e. the distance between bottom wall  231  and the top wall  233  is widest at the rear end w′ and continuously decreases to reach a constant width w″ at about the middle of the total longitudinal extension of the recess  230 . Preferably the width w′ at the rear end is at least double the width w′ at the front portion according to the shown embodiment the maximum width w′ is about 100 mm and the constant width w″ about 20 mm. Moreover it is shown in  FIG. 5  that the top wall  233  is inclined to form an angle α in relation to the extension of the plane of the bottom wall  232 , making the recess wedge-shaped in a vertical cross-sectional, i.e. creating a wedge-shaped corner area  233 A. Thanks to this wedge-shaped design of the recess  230  an interfitting portion of the propulsion unit  100  having a corresponding shape will be retained therein hindering the sides of the hull unit  100  to move out of contact with the propulsion unit  100 A, once in position. Further the design of the recess  230  allows for having the propulsion unit slid into the hull unit  200  from the behind to safely engage the two units  100 ,  200 , and moreover the design is such that it does not totally seal between the flange  105  and the recess  230 , but assist in self-bailing of water from the foot rest area  202 . 
       FIG. 5  further shows that the central portion  200 A at its side periphery is arranged with an L-shaped outwardly extending area  240  and that each side portion  200 A,  200 B is arranged with a corresponding L-shape to fit into, and be supported by the central portion  200 A. By means of welds  241 ,  242  the side portions  200 B,  200 C, basically functioning as fenders which at the same time forms the hull, are fixedly attached to the central portion  200 A. Thus, the hull unit ( 100 ) comprises a central portion ( 200 A) being provided with a non-straight lined area ( 240 ) arranged to support and position said at least one further portion ( 200 B,  200 C). 
     In  FIGS. 3, 6, 7 and 8  there are shown details of the propulsion unit  100 . The propulsion unit  100  is made in a material that is less flexible, i.e. more rigid, than the material used in the hull unit  200 . Accordingly the propulsion unit  100  provides for the stability/rigidity of the whole vessel. Indeed, thanks to the rigid design of the propulsion unit  100  the vessel  100 ,  200  is strong enough to be transported by a helicopter in high speed, e.g. hanging underneath the helicopter at a speed of up to 88 knots. The preferred material used in at least major parts of the propulsion unit  100  is some kind of composite material, e.g. a curable resin having fibre reinforcement. A suitable material is any traditional kind of fibre and curable resin, e.g. glass fibre and polystyrene or polyester, used frequently for production of hull structures to smaller boats/vessels. As already explained the inner space  150  of the propulsion unit  100  is intended for the drive unit (not shown), which is fitted therein in a manner known per se and will therefore not be described more in detail. Further as mentioned the propulsion unit  100  is intended to provide stability to the vessel, e.g. to enable lifting of the vessel without breaking. In this context the inner side walls  102  and the outer side walls  101  are sufficiently reinforced to withstand the forces that are produced when lifting the vessel and/or when riding the vessel in any situation that it is intended to withstand. Further to provide extra stability the space intermediate inner wall  102  and the outer wall  101  is provided with stabilising wall material  120 , e.g. a foam material such as divinicell. At the position  104  there are shown recesses  104  formed at the outer sides of the propulsion unit  100 , at and around the upper edge, to provide attachment for a casing comprising electrical details of the vessel, e.g. generator. Further, there is shown that in front of said casing there is indicated positioning of a sealed box  400  containing the electric control system, which is shown in more detail in  FIG. 8 . 
     Further  FIG. 3  schematically presents that there is a support device  300 , which comprises a generally U-shaped mounting  310 , which end-pieces are attached to the propulsion unit  100  (not shown) and onto which, at the top, there are arranged accessories/equipment  301 - 304 . Among other things there is shown a navigation/position light  301 , a bumper device (e.g. rubber foam)  302  fixed onto the bottom of the position light  301 , a handheld torch  303  and a flash-lamp  304 . The flash-lamp  304  is especially designed to be compact and to require relatively low power, by means of using a blue flash-lamp. To be easily detectable from the sky the flash-lamp  304  has a cover that is transparent upwardly, and of course also at the sides to be detectible by other boats. The torch  303  is realisably attached to the mounting  310  by means of suitable means (e.g. resilient ribbons, not shown). Accordingly the torch  303  may be used in a flexible manner to try to find people in need. Preferably the torch has a high power output, to provide excellent luminance, and therefore the switch (at the handle) of the torch  303  is preferably connected to the electric control unit  400  in such a manner that when the torch is lit other power consuming functions, e.g. heating of handles and/or under water light, will be turned off, to household with the power supply. 
     Further, as is indicated in  FIG. 3 , the electric control unit  400 , at its top, is arranged with at least one switch  401 ,  402 . Preferably there is one switch  401  to control high or low heat for the handles and one switch  402  to facilitate emergency activation of the blue flash-lamp  304  and/or an AIS-transponder. Moreover there is a transparent portion  403 , also arranged in the upper wall (e.g. the lid) of the sealed box  400 , by means of which certain elements within the sealed box  400  may easily be visually supervised/checked up on. 
     Extending along the sides and around the front of the propulsion unit  100 , adjacent the lower part thereof, there is a flange  105  forming the interlocking device intended to interlock with the recess  230  of the hull unit  200 . The flange  105  has a top surface  108 , belonging to an intermediate portion  100 A, and bottom surface  109 , belonging to a bottom portion  100 B, which are rigidly connected to each other. Hence, the flange  105  is formed in the joint between these two portions  100 A,  100 B and extends from adjacent the aft III of the propulsion unit  100  all the way around the front to the other side. Along a substantial portion, from the aft to about the middle of the flange  205 , on each side, there are arranged interlocking extensions  110 , which extensions present continuously increasing length l closer to the aft of the propulsion unit. Accordingly the length l′ close to the middle of the propulsion unit  100  is smaller than the length l″ at the rear of the propulsion unit. The edge area  110 A of the interlocking extension  110  will interlock into the wedge-shaped corner area  233 A of the wedge-shaped recess  230  and the bottom surface  109  of the flange  105  will assist in the interlocking action by interacting with the lower wall  232  of the recess  230 . Accordingly the design of the flange  105 , having interlocking extensions  110 , will safeguard that the hull portion  200  will safely interlock onto the propulsion unit  100  once the two units have been slid into contact with each other. Thanks to the propulsion unit  100  pushing into the hull unit  200  during propulsion there is no big need for any securing attachments, especially considering that friction forces within the interlocking devices  230 ,  105  will assist to keep the units in position. However there are arranged through-holes (see adjacent edge  205  in  FIG. 2 ) in the hull portion  200  and the propulsion unit  100  to fix them in interlocked positions, by means of pins (not shown). 
     Further  FIG. 7  presents a protruding portion  140  of the flange  205 , at the front end of the propulsion unit  100 . The protruding portion is arranged with a through hole  141 , intended for fixing of a rope (not shown). The rope is intended to pass out through the hull portion  200  by means of a through hole  217 ,  213 , to have the rope of the vessel securely fixed to the rigid propulsion unit  100 . Moreover there is shown a longitudinally extending channel  160 , the purpose of which is to provide extra stability/strength and to provide space for attachments for tank, engine, etc. 
     In  FIG. 8  there is a figure showing some principles of the electrical control unit arrangement  400 . All of the electrical components (not shown) are encased within a sealed box comprising a box portion  410  and a lid portion  420 . These two portions  410 ,  420  are designed such that when their opposing edges  422 ,  412  enter into contact they will seal and retain the portions  410 ,  420  together. In an alternative embodiment (not shown) the lid  420  is arranged by means of hinges along one side of the box portion  410  and an easy assessable locking handle being used to close and open the lid  420  respectively. 
     All the electrical components (not shown) are securely attached to a frame unit  430  (e.g. a punched out and folded metal plate) presenting a number of different support structures  431  and a number of openings  432  to fixedly hold the different components in desired positions. The position are chosen such that it will be easy to install each component and also to repair/perform maintenance. In a preferred embodiment the support structure  430  is not fixedly attached to the box  400 , but is squeezed into a fixed position between the bottom surface  411  of the box portion  410  and the inner surface  421  of the lid portion  420 . This is achieved by having the support structure  430  arranged with a lower face being in stable contact with the bottom surface  411  and at least two upwardly protruding parts  433  of the support structure  430 , each being arranged with a resilient knob device  430  at the top, such that when the lid portion  420  is in its closed position it will press the support structure  430  via the resilient knobs  413  into firm contact with the bottom surface  411  of the box portion  410 . Further there is shown a separate, tray formed, device  440 , which is adapted to contain an AIS-transponder, which tray  440  may be attached to the inner surface  421  of the lid portion  420 . Further the box  400  preferably contains a separate battery for emergency power to said AIS-transponder and/or the flash lamp  304 . 
     Not shown in the figures is a beneficial design of the antenna that is being used, which is a wishbone-construction that uses a frictional device to be collapsed. Another aspect that is not directly shown in the figures is the use of a lid on the top of the opening  154  in the propulsion unit  100  that facilitates quick and easy access to the water jet, e.g. to remove undesired objects. 
     The invention is not limited by the embodiment described above but may be varied within the scope of the appended claims. For instance, it is evident that the skilled person may find many different kind of materials that may be combined in a obvious manner to produce desired properties, e.g. depending on various differing needs of the vessel being produced, e.g. if intended to be used in a sea normally having large waves or if used in a lake normally having smaller waves. Moreover it is understood that the exact shape of the interlocking recess of the hull unit and the interlocking flange device  205  of the propulsion unit may be formed in many various altering shapes, but still producing the same kind of function, i.e. safeguarding the hull unit  200  of a more flexible material to be safely attached to the rigid propulsion unit  100 . For instance it is evident that the creation of flange device  105  having a cross-section that totally corresponds to the cross-section of the recess is an evident option, which may be desired if increased strength is desired. However in most applications the use of an interlocking extension  110  is sufficient and therefore preferable due to being more cost efficient. Further it is evident that the design may easily be adapted to use of different kind of driving unit than the one presented in the shown embodiment, and that indeed in some applications another kind of driving unit may be desired.

Technology Classification (CPC): 1