Abstract:
A recreational vessel for carrying a plurality of passengers capable of movement on land and in water. The recreational vessel includes an upper section with passenger seating, and lower section having an engine, a transmission, a marine propulsion unit, and at least two sets of wheels joined by axles. The upper and lower sections are separated by a deck plate. The lower section forms a pod-free and watertight hull which is designed to maximize both the aerodynamic and hydrodynamic efficiency of the vessel. Located between the deck plate and the inner bottom surface of the hull is an engine, which is centered within the hull and is coupled to a transfer case. The transfer case is coupled to a first drive shaft and to a second drive shaft. The first drive shaft is connected to two axles to effect the rotation of the two axles. The second drive shaft is connected to and drives the marine propulsion unit. The vehicle further is equipped with a spring-loaded ladder.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to transportation devices. More particularly, the present invention relates to vessels that are capable of movement both on land and in water. Still more particularly, the present invention is related to amphibious recreational vessels.  
         [0003]     2. Description of the Prior Art  
         [0004]     Vehicles that may be both driven on land and navigated on water, or what are commonly referred to as amphibious vehicles, have been used by the United States military in its operations worldwide. Amphibious vehicles also have been used by civilians for recreational purposes. These amphibious recreational vehicles are routinely used to transport tourists as part of sightseeing tours over roadways and along waterways in some U.S. cities.  
         [0005]     Present amphibious recreational vehicles, however, have significant flaws. For one, whether they are being operated on land or on water, they are highly fuel inefficient. Further, they are difficult and costly to maintain. Even further, they are not optimally designed to accommodate all passengers. Indeed, some passengers, including some elderly and physically challenged persons, find it difficult to embark and disembark these vehicles.  
         [0006]     Some of these flaws are attributable to the fact that they are primarily floatable trucks. Specifically, present amphibious recreational vehicles may be thought of primarily as being terrain vehicles, and more specifically, trucks, which are modified for use in water. For this reason, these vehicles have body frames and drive trains that mimic those typically seen in trucks. For example, consider the amphibious vehicle described in U.S. Pat. No. 6,482,052 issued to Giljam. The drive train of the Giljam vehicle includes among other parts a truck engine, an ignition system, a transmission, a power splitting device, two drive shafts, and various control system components. A third drive shaft is included for operating a marine propulsion means which is located at the rear of the vehicle. Also included as part of the drive train is a radiator which must be proximate to the engine for proper engine functioning.  
         [0007]     Much of the Giljam drive train resides in a large pod that extends concavely downward from the bottom of the vehicle&#39;s hull. Included in the pod is the engine, which is positioned at one end of the drive train. In this arrangement, the engine is not centrally located within the entire vehicle, but instead lies closer to the front of the vehicle than to its back. However, placing the engine, which is substantially heavy, aft of center causes the weight of the entire vehicle to be unevenly proportioned. To help compensate for this imbalance, the Giljam vehicle includes foam filled compartments, which are said to provide stability and buoyancy to the vehicle.  
         [0008]     U.S. Pat. No. 6,575,796 issued to McDowell is another example of a vehicle having a truck-like drive train and body frame. The McDowell patent describes a drive train for an amphibious vehicle. Among its other parts, the McDowell drive train includes an engine which is connected to a transmission. The transmission also is connected to a transfer case, which is further connected to a gearbox. The gearbox also is connected to a first propeller drive shaft, which is further connected to a second propeller drive shaft, which is further connected to a propeller.  
         [0009]     Like the Giljam engine, the McDowell engine is aft of center in the vehicle, and specifically is located near the extreme front end of the vehicle. Also like the Giljam vehicle, the bottom of the McDowell vehicle&#39;s hull is not flat or uniformly shaped, but instead extends downward at the area of the hull located between its front wheels and rear wheels, thereby effectively creating a pod-like structure in the hull. This pod-like structure houses several of the drive train components.  
         [0010]     One of the limitations of these truck-like drive trains is that they have a number of parts, such as the radiator of Giljam and the gearbox of McDowell, that do little or nothing to improve the operation or efficiency of the vehicle, particularly when in the water. Therefore, these drive trains could be redesigned such as to not include these unneeded parts without reducing the utility of the vehicle. Moreover, not having these unnecessary parts actually would provide two advantages. First, having fewer parts would reduce the probability that the vehicle will breakdown due to failure of one of these parts. Second, eliminating unneeded parts would cause the weight of the vehicle to be reduced, which in turn would cause the fuel efficiency of the vehicle to be increased.  
         [0011]     Other aspects of prior amphibious vehicles, such as those of McDowell and Giljam, also contribute to these performance problems. For example, consider the pod of each vehicle, which, by causing the drag coefficient of the vehicle to be increased while the vehicle is being operated both on land and on water, effectively reduces both the aerodynamic and hydrodynamic properties of the vehicle. Because even slight increases in a vehicle&#39;s drag coefficient can cause a substantial reduction in fuel efficiency, vehicles like those of McDowell and Giljam, whose pod effects a great increase in the drag coefficient, are therefore not optimally fuel efficient.  
         [0012]     As another example, consider the foam filled compartments of Giljam, which Giljam states are required to negate the imbalance that positioning the engine aft of center has on the weight distribution of the vehicle. The foam filled compartments, which would be wholly unnecessary to a vehicle having a well-balanced weight distribution make the vehicle more difficult to maintain. This is true because their foam occasionally must be replaced, and because they can obscure other parts of the vehicle which occasionally must be repaired.  
         [0013]     Yet another drawback to present amphibious recreational vehicles, and one which is not related to body frame design or to nature of the drive shaft, is that some passengers find them difficult to embark and disembark. Indeed, some elderly and handicapped persons, for example, have trouble embarking and disembarking these vehicles.  
         [0014]     What is needed therefore is an amphibious vehicle which is easy and inexpensive to maintain, has an improved mileage-to-fuel consumption ratio, and is easy for all passengers to enter and exit.  
       SUMMARY OF THE INVENTION  
       [0015]     It is an object of the present invention to provide an amphibious recreational vessel, which specifically is a vessel capable of movement on land and in water.  
         [0016]     It also is an object of the present invention to provide an amphibious recreational vessel that has all of the advantages of a water vessel, including those provided by body design and part composition, and which does not have the limitations that accompany amphibious vehicles having a truck-like body frame and drive train.  
         [0017]     Further, it is an object of the present invention to provide an amphibious recreational vessel that is both easy and inexpensive to maintain. Toward this goal, the amphibious recreational vessel of the present invention includes a reduced number of parts. The invention therefore has fewer parts that need to be maintained, and which otherwise would inconveniently obscure access to other parts of the invention that are in need of repair.  
         [0018]     It is another object of the present invention to provide an amphibious recreational vessel that is optimally designed to maximize the vessel&#39;s mileage-to-fuel consumption ratio when the vessel move on land and in water. Toward this end, the frame of the vessel, including its hull, is optimally designed to be both aerodynamic and hydrodynamic. Additionally, since the vessel of the present invention has fewer drive train components than do truck-like amphibious vehicles, the weight of its drive train is minimized, which in turn helps to maximize the vessel&#39;s mileage-to-fuel consumption ratio on land.  
         [0019]     It is yet another object of the present invention to provide an amphibious recreational vessel that is optimally designed to accommodate passengers of all physical ability. The present invention therefore is equipped with a ladder, which may be spring-loaded, and which may be used by all passengers, including the physically challenged, for both entering and exiting the vessel.  
         [0020]     The details of one or more examples related to the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a first elevation view of the starboard side of the vessel of the present invention.  
         [0022]      FIG. 2  is a second elevation view of the starboard side of the vessel of the present invention with a cut out of the hull to show parts of the drive train.  
         [0023]      FIG. 3  is an elevation view of the port side of the lower section and the components of the drive train of the vessel of the present invention.  
         [0024]      FIG. 4  is a plan view of the lower section and the components of the drive train of the vessel of the present invention.  
         [0025]      FIG. 5  is an elevation view of the front end of the vessel showing the ladder in a stowed position.  
         [0026]      FIG. 6  is an elevation view of a portion of the front end of the vessel showing the ladder in a deployed position.  
         [0027]      FIG. 7  is an elevation view of a portion of the front end of the vessel showing the bow thruster and front bumper combination.  
         [0028]      FIG. 8  is a plan view of the front end of the vessel showing the bow thruster and front bumper extending the width of the vessel at the bow. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]     The present invention is a recreational vessel capable of movement on land and in water. The present invention, therefore, is an amphibious recreational vessel. Referring to  FIGS. 1-4 , the vessel  10  includes an upper section  100 , having a deck surface  105 , and a lower section  200 . The upper section  100  and the lower section  200  are separated by a deck plate  110 . The deck plate  110  contains a watertight hatch  120  which enables the lower section  200  to be accessed from the upper section  100 .  
         [0030]     In a preferred embodiment of the present invention, shown in  FIG. 1 , the entire length of outer bottommost surface  205  of the lower section  200 , which specifically is the surface of the vehicle  10  most distal to the upper section  100 , is flat. In an alternative embodiment, which is not shown, the entire outer bottom surface  205  extends concavely in a direction away from the upper section  100 . Further, the lower section  200  does not contain a pod or any pod-like structure in any embodiment of the present invention. Because it does not have a pod or a pod-like structure, the outer bottommost surface  205  of the lower section  200  is able to set close to the ground when the vessel  10  is on land.  
         [0031]     Further, the lower section  200  forms a hull  210 . The hull  210  has both a starboard side  213 , which is shown in  FIG. 1 , and a port side  216 , which is shown in  FIG. 4 . Located both at the inside bottom surface  218  of the hull  210  and within the hull  210  are a first bilge tank  220  and a second bilge tank  220 ′. Specifically, the first bilge tank  220  is located on the starboard side  213  of the inner bottom surface  218  of the hull  210 , and the second bilge tank  220 ′ is located on the port side  216  of the inner bottom surface  218  of the hull  210 .  
         [0032]     Referring to  FIG. 2 , included between the first section  100  and the bilge tanks  220  and  220 ′ is an engine  230 , which is essentially centered between the bilge tanks  220  and  220 ′. The placement of the engine  230  to a central position  235  within the hull  210  of the vessel  10 , and therefore within the vessel  10  itself, enhances vessel  10  stability. The engine  230  is coupled to a transfer case  240 . The transfer case  240  is positioned at the inner bottom surface  218  of the hull  210  between the bilge tanks  220  and  220 ′. The transfer case  240  is further coupled to a first drive shaft  250  and a second drive shaft  260 . The first drive shaft  250  passes through a first hole  255  of the hull  210  and is further coupled to a first axle  400  which is included as part of the lower section  200 . The second drive shaft  260  passes through a second hole  265  of the hull  210  and is further coupled to a marine propulsion unit  270 . The marine propulsion unit  270  may be, but is not limited to being, a propeller. The marine propulsion unit  270  also may include, but is not limited to including, a bow thruster. An exemplary bow thruster which may be used is the American Bow Thruster TRAC™ system, which is made available by Arcturus Marine Systems of Rohnert Park, Calif. A thruster is a propeller located at the front (bow) of a watercraft or rear (stern) of the watercraft. It is generally located at the lower sea-covered part of the watercraft. It is arranged to turn at right angles to the fore-and-aft line of the watercraft and thus provides transverse thrust as a maneuvering aid. The present invention contemplates the option to use a bow thruster in combination with a propeller, a stem thruster in combination with the propeller, or the combination of all three.  
         [0033]     As shown in  FIG. 4 , also included as part of the lower section  200  is a second axle  410 . Connected to each of a first end  403  of the first axle  400 , a second end  406  of the first axle  400 , a first end  413  of the second axle  410 , and a second end  416  of the second axle  410  is a wheel  420 . In this arrangement, each wheel  420  may be fully rotated in both a clockwise direction and a counterclockwise direction.  
         [0034]     The vessel  10  is designed to be optimally safe. In addition to centrally placing the engine  230  within the vessel  10  for the purpose of giving the vessel  10  stability, the upper section  100  of the vessel  100  is watertight, such that water contained on the surface of the upper section  100  cannot pass the deck plate  110  to enter the lower section  200 . Further, the vessel  10  may include a plurality of high air intake openings  500  and exhaust openings  510 , which allow fresh air from outside the vessel  10  to be continuously exchanged with the air inside the lower section  200 , which may contain, for example, exhaust fumes. In a preferred embodiment of the present invention, the high air intake openings  500  are National Advisory Committee for Aeronautics (NACA) ducts. The NACA duct or NACA scoop is a common form of low-drag intake design. When properly implemented, it allows fluid to be drawn into an internal duct, often for cooling purposes, with a minimal disturbance to the flow. See Frick, Charles W.; Davis, Wallace F.; Randall, Lauros M.; and Mossman, Emmet A.:  An Experimental Investigation of NACA Submerged Duct Entrances  NACA ACR 5120, 1945 for background information on the original NACA duct development. NACA ducts are preferred in regard to the vessel  10  because they shed water efficiently while the vessel  10  is moving on water. It is to be understood, however, that the high air intake openings  500  are not limited to being NACA ducts.  
         [0035]     The vessel  10  may be used to transport a plurality of passengers. To facilitate passenger transportation, the vessel  10  may be include a plurality of seats  130 , such as those shown in  FIG. 2 , which are connected to the deck surface  105  of the upper section  100 .  
         [0036]     Further facilitating passenger transportation is one or more spring-loaded ladders  600  which passengers may use to enter and exit the vessel  10 . The one or more spring-loaded ladders  600  may be located on the port side  216 , the starboard side  213 , and/or the back end  215  of the vessel  10 .  
         [0037]     In a preferred embodiment of the vessel  10  of the present invention as shown in  FIGS. 5-6 , the vessel  10  has one spring-loaded ladder  600  having a first end  603 . The first end  603  is connected to the vessel  10  at position  610  which is near door  620 . The ladder  600  may be folded such that a second end  608  of the ladder  600  contacts, or nearly contacts, section  605  of the ladder  600 , in what may be referred to as its “closed” arrangement. Specifically, section  605  may be any region of the ladder  600  between first end  603  and second end  608 . Further, when the ladder is in the closed arrangement, the ladder  600  may be reversibly locked to prevent second end  608  from being substantially removed from contacting, or nearly contacting, section  605 . It may be preferred to keep the ladder  600  locked in the closed position, for example, when the vessel  10  is in motion.  
         [0038]     When locked in the closed position, second end  608  of the ladder  600  may be unlocked by an individual. When unlocked, second end  608  may be removed from section  605 , and may be extended to contact, or nearly contact, the land or water below the vessel  10 . In this arrangement, which may be referred to as the “open” arrangement, the ladder  600  may be locked to stabilize the second end  608 . Further, in one embodiment of the open arrangement of the ladder  600  of the present invention, the ladder  600  may be securely held into a position which is essentially parallel to outer face  203 . Alternatively, in a second embodiment of the open arrangement of the present invention, the ladder  600  may be securely held into a position which is not essentially parallel to outer face  203 . For example, the ladder  600  may be held, but is not limited to being held, in a position at or near the land or water which is 30 degrees removed away from the outer surface  203  of the vessel  10 . It may be preferred to lock the ladder  600  in the open position, for example, when passengers are entering or exiting the vessel  10 .  
         [0039]     An added benefit of the ladder  600  is that it may be used to rescue an individual in the water when the vessel  10  is in water. In that situation, the ladder may be lowered into the water partially and then locked in that position. Once the ladder  600  is locked in position, a person may step on its rungs and remain on the ladder  600  while also in the water near the individual in need of rescue. The rescuer is therefore in a more stable situation and able to use the ladder  600  for support while aiding the individual. Alternatively, the individual in need of rescue may reach the ladder  600  more easily after it has been lowered into the water and may then pull himself/herself onto the ladder  600 .  
         [0040]     The vessel  10  may further optionally include a bow thruster system  700  as shown in  FIGS. 7 and 8 . The bow thruster system includes a thruster  702  and a bumper  704 . The thruster  702  includes a propulsion component such as impeller  706 . The bumper  704  is formed of one or more conduits or pipes extending substantially the entire width of the vessel  10  at bow/front  708  below waterline  710 . The bumper  704  is affixed to the hull  210  such as by welding. It may be covered partially or entirely by a resilient material, such as a viscoelastic material. The thruster  702  forms part of, and is substantially aligned with, the bumper  704  at the centerline thereof. The thruster  702  may also be substantially aligned with the centerline of the vessel  10 . A thruster conduit  712  extends through a port  714  of the hull  210  and is affixed to the thruster  702 . The thruster conduit  712  is also affixed to a control box  716  including electronics and/or power supply arranged to cause movement of the impeller  706 . The thruster  702  may be controlled for reversible and variable movement of the impeller  706  by a control component, such as a joystick, accessible by the vessel&#39;s pilot.  
         [0041]     In one embodiment of the invention, the bumper  704  may be two independent conduits having inside diameter substantially conforming with the inside diameter of the thruster  702 . The thruster  702  is preferably first bolted onto and through the hull  210  at the vessel centerline. The two pieces of the bumper  704  are then butted to the thruster  702  and affixed to the exterior of the hull  210 . This arrangement establishes a portal through which water may be forced by operation of the thruster  702 . The thruster  702  may be hydraulic and plumbed into the relevant existing vessel components as understood by those skilled in the art, or it may be electrical (as shown) and wired into the existing vessel electrical system as understood by those skilled in the art. The thruster  702  may be the same type of bow thruster described hereinabove.  
         [0042]     The bow thruster device  700  is arranged to aid in low-speed maneuvering of the vessel  10  while it is in the water, particularly low-speed transverse maneuvering. Specifically, when activated to rotate in a first direction, the impeller  706  causes movement of water through the bumper  704  in a first direction, causing localized opposing movement of the vessel in the opposite direction. Similarly, the impeller  706  may be rotated in a second direction different from the first to cause movement through the bumper  704  in the opposite direction. This results in movement of the vessel  10  in a second direction opposite from the flow of water through the bumper  704 .  
         [0043]     While the present invention has been described with particular reference to certain embodiments of the amphibious recreational vessel, it is to be understood that it includes all reasonable equivalents thereof as defined by the following appended claims.