Abstract:
An amphibious vehicle, mostly watercraft in appearance, has a single drive system that accelerates, propels, steers, reverses, and brakes the vehicle on land or in the water. This control is effectuated by one or both twin control levels positioned to the left and right of the vehicle operator. Rear mounted propulsions units include a paddlewheel and tire combination, which operate independently and are rotatable in either direction.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to vehicles, and more specifically, to an amphibious vehicle having a single drive system that runs the vehicle whether it is on land, or in water. 
         [0002]    There are many circumstances where it is necessary or desirable to have an amphibious vehicle. Examples of situations where amphibious vehicles are used include recreation, flood rescue, thin ice rescue, hunting, fishing, and traveling through areas having both water and solid surfaces. 
         [0003]    However, operating in water and on solid surfaces presents vastly different engineering challenges, as evidenced by, for example, cars and boats looking and functioning very differently. The typical way to overcome these engineering challenges in an amphibious vehicle is to provide dual systems for steering, braking, reversing, and so forth—one for water use and one land use. Unfortunately, however, this duplicative engineering renders the resulting vehicle complicated, expensive, and/or more prone to breakage. 
         [0004]    While military amphibious vehicles are very durable, they are too complicated to operate and expensive to operate for general civilian use. 
         [0005]    As can be seen, there is a need for an amphibious vehicle which is structurally relatively simple, easy to operate, and less expensive to produce than other amphibious vehicles, so as to reasonably lend itself to purchase and use by the population at large. It is desirable that this vehicle has a single drive system, versus duplicative systems for use in water versus solid surfaces. 
       SUMMARY OF THE INVENTION 
       [0006]    Embodiments of the present invention include an amphibious vehicle having a single drive system that accelerates, propels, steers, reverses and brakes the vehicle on land and water. A pair of spaced propulsion assemblies are each conjoined rubberized tire and paddlewheel hybrids. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a forward perspective view of an embodiment of the invention shown in use on a solid surface; 
           [0008]      FIG. 2  is a forward perspective view of an embodiment of the invention shown in use on water; 
           [0009]      FIG. 3  is a side perspective view of an embodiment; 
           [0010]      FIG. 4  is a top view of an embodiment; 
           [0011]      FIG. 5  is a side view of an embodiment; 
           [0012]      FIG. 6  is a front view of an embodiment; 
           [0013]      FIG. 7  is a detail side view of an embodiment illustrating item  12  free wheel in land and water configuration; 
           [0014]      FIG. 8  is a rear perspective view of an embodiment; 
           [0015]      FIG. 9  is a detail rear perspective view of an embodiment illustrating rotational motion of propulsion units; 
           [0016]      FIG. 10  is a rear perspective view of an embodiment demonstrating component relationships; 
           [0017]      FIG. 11  is a forward perspective view of a three-wheeled embodiment of the invention shown in use; and 
           [0018]      FIG. 12  is a side view of a three-wheeled embodiment of the invention. 
           [0019]      FIG. 13  is a front view of a three-wheeled embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
         [0021]    The following structure numbers apply among the various FIGS: 
         [0022]      10  is an operator; 
         [0023]      12  is a free wheel; 
         [0024]      14  is a shell; 
         [0025]      16  is a hydro-propulsion unit; 
         [0026]      18  is an engine; 
         [0027]      19  is a hydrostatic transmission; 
         [0028]      20  is a solid driving surface; 
         [0029]      22  is a seat; 
         [0030]      24  is a control lever; 
         [0031]      26  is a drive wheel; 
         [0032]      28  is a body of water; 
         [0033]      30  is a four-wheel embodiment; and 
         [0034]      32  is a three-wheel embodiment. 
         [0035]    Broadly, an embodiment of the present invention provides an amphibious vehicle, mostly watercraft in appearance, which is as capable on land as it is in the water. The main components of the vehicle include a floatation shell, engine, controls, hydraulic drive with hydro-propulsion and drive wheels. 
         [0036]    Referring to the FIGS, shell  14  provides floatation as well as the framework upon which the other components are affixed. It is preferably boat-like and constructed of lightweight yet strong and water resistant materials such as aluminum, plastic or fiberglass, and is formed in a traditional boat shape having a concave bottom-side and substantially hollow center which is accessed by passengers through the top. Alternatively, it is within the scope of this invention to use inflatable boats, pontoons, canoes, kayaks or the like as shell  14 . 
         [0037]    The vehicle is operated using a pair of control levers  24 , preferably mounted on either side of seat  22 . These levers are multi-directional and multi-functional, with some functions requiring one lever, and some functions requiring both. 
         [0038]    Engine  18  is preferably a conventional gasoline engine, and powers a hydraulic drive system. The engine&#39;s speed is controlled by a separate, preset, throttle control lever, while acceleration rate and vehicle speed are determined by the interaction of both controllers  24 . 
         [0039]    Referring to  FIGS. 9 and 10 , left and right propulsion assemblies are generally mounted rearward, and include the combination of hydro-propulsion unit  16  and drive wheel  26 . Hydro-propulsion unit  16  is preferably a paddlewheel assembly. It is desirable that the propulsions assemblies are substantially permanently connected and conjoined, such that they rotate in unison, are free to rotate in either direction (clockwise and counterclockwise) to effectuate both forward and reverse driving, and are mounted outboard. It is preferred that drive wheel  26  is located towards the back of the vehicle includes a rubberized tire suitable for solid surface driving, and is minimally larger in diameter than paddlewheel of hydro-propulsion unit  16 , such that paddlewheel assembly isn&#39;t in contact with solid driving surface  20  in use. The left and right propulsion assemblies are each controlled independently by the operator. 
         [0040]    Left and right hydrostatic drive units  19  connect engine  16  with the left and right propulsion assemblies. Each hydrostatic drive unit  19  (left and right) is in communication with, and operatively controlled by, left and right control levers  24 , which control the direction and speed of each of the propulsion assemblies. It should be noted that different drive systems that provide variable speed in both forward and reverse may be suitable for this invention, but that hydrostatic transmissions are preferred. Left and right drive assemblies can be used to drive either propulsion unit (left or right) in the same direction or in opposite directions. Steering, braking and propulsion are all accomplished with control levers  24 . When the propulsion units are driven in opposite directions the vehicle makes a zero-radius turn. This is a so called ‘zero-turn’ amphibious vehicle. 
         [0041]    Free wheel  12  is preferably located towards the front of the vehicle, is for land use and is preferably a freely rotating wheel, such as a caster wheel. It is desirable that free wheel  12  can be retracted while in the water, as depicted in  FIG. 7 . The invention includes an embodiment having a single free wheel  12 , depicted in  FIGS. 11-13 , as well as an embodiment having dual free wheels  12 , depicted in  FIGS. 4 and 10 . Factors such as weight, weight distribution and shape of the vehicle may be determinative of employing a single or dual wheel. 
         [0042]    To operate this vehicle on land or water the operator is seated inboard with one control lever  24  at each hand. Forward, neutral and reverse action are effectuated by varying the acceleration using control levers  24 , with each left and right controller  24  independently controlling the corresponding left and right propulsion unit. Maneuvering the vehicle is accomplished by changing the speed or direction of the propulsion units using the controllers. When both controllers are pushed forward simultaneously with the same force, the vehicle moves forward. When both controllers are pulled back simultaneously with the same force, the vehicle moves backward. Braking is effectuated in the forward moving vehicle by moving the controllers back. Braking is effectuated in the reverse moving vehicle by moving the controllers forward. A gentle turn is effectuated by pushing one controller more than the other. A zero-radius turn or zero turn is effectuated by pushing one controller forward and pulling the other controller back. 
         [0043]    It is possible to fabricate, manufacture and assemble the vehicle for delivery to a user, or sell as a kit for assembly by an end user. As used herein, “single drive system” and the like shall refer to the mechanical components which collectively function to drive the vehicle, including acceleration, propulsion, steering and braking. It is important to note that the present invention uses a single drive system for land and water transportation. In other words, one steering system is employed for steering on land or water, one set of controllers is employed for directing the vehicle on land or water, and so forth. No components of the drive system are duplicative for purposes of having a structure for use in land transportation and a different structure for use in water transportation. The hydro-propulsion unit  16  and drive wheel  26 , collectively called (but not numbered) the “propulsion assembly” is not considered to be part of the “hydraulic drive system” or “drive system”, which includes the controller, engine and hydrostatic transmission. 
         [0044]    It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. Examples of modifications within the scope of this invention include varying the location of the hydro-propulsion unit  16  and/or free wheel  12  locations. The propulsion units  16  and drive wheel  26 , are opposite one another, but can be located fore, aft or in the center, with free wheel  12  located accordingly, aft, fore or both. They can be singles or in pairs. Vehicle control will be similar in all wheel locations but the degree of difficulty exiting the water will change with variations in drive and free wheel configurations. By way of example, the hydro-propulsion units may not push the free wheels up a steep incline, for example a boat ramp, if located in the center, but the vehicle can back up the incline if wheels are located in the conventional position. The twin control levers  24  can be replaced with single or dual joysticks, with the control remaining the same. It should also be understood that ranges of values set forth inherently include those values, as well as all increments between.