Amphibious vehicle

Abstract

A sit-astride amphibious vehicle configuration which supports a high performance envelope both on land as well as in water. The vehicle has a planing hull and four retractable wheels. Handlebars provide for directional control in both modes of operation. Each road wheel is retractable by pivoting through at least 45° so as to maximize ground clearance when in the land mode of operation and to minimize drag at substantial lean angles when in the marine mode of operation. While a jet drive may remain directly connected to the engine at all times, the driven wheels are only connected during land mode via a speed-change transmission. The entire power train is supported by a frame that is separable from the hull which in turn has a detachable top deck portion, whereby such configuration simplifies the construction, repair and servicing of the vehicle.

What is claimed is: 
     
         1 . An amphibious vehicle comprising:
 a sit-astride seat,   a planing hull,   at least four wheels, each of which is movable between an extended land mode location and a retracted water mode location two of the wheels being front steerable wheels, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one of the wheels to drive the wheel, and   marine propulsion means to propel the vehicle on water.   
     
     
         2 . An amphibious vehicle as claimed in  claim 1 , wherein:
 the engine drives the marine propulsion means to propel the vehicle on water.   
     
     
         3 . An amphibious vehicle as claimed in  claim 1 , comprising additionally:
 a speed change transmission giving the vehicle in forward motion on land a plurality of different gear ratios between the engine and the driven wheel(s).   
     
     
         4 . An amphibious vehicle as claimed in  claim 1 , wherein:
 all of the four wheels are each pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof.   
     
     
         5 . An amphibious vehicle as claimed in  claim 2 , comprising additionally:
 a speed change transmission giving the vehicle in forward motion on land a plurality of different gear ratios between the engine and the driven wheel(s).   
     
     
         6 . An amphibious vehicle as claimed in  claim 2 , wherein:
 all of the four wheels are each pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof.   
     
     
         7 . An amphibious vehicle as claimed in  claim 3 , wherein:
 all of the four wheels are each pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof.   
     
     
         8 . An amphibious vehicle as claimed in  claim 5 , wherein:
 all of the four wheels are each pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof.   
     
     
         9 . An amphibious vehicle as claimed in  claim 1 , wherein:
 the two front steerable wheels in land mode locations thereof are located on opposite sides of the vehicle, spaced apart transversely across the vehicle by a first track width;   the two other wheels of the four are not connected to the handlebars to be steered thereby and are located at the rear of the vehicle on opposite sides of the vehicle, spaced apart transversely across the vehicle by a second track width greater than the first track width.   
     
     
         10 . An amphibious vehicle as claimed in  claim 1 , wherein:
 a separate spring and damper unit is provided for each wheel.   
     
     
         11 . An amphibious vehicle as claimed in  claim 1 , wherein:
 a track rod is mounted to extend transversely across the vehicle; the track rod is mounted by mounting means which allow the track rod to be slid along the axis thereof transversely across the vehicle by rotation of the handlebars; the track rod is pivotally connected at one end to a first front wheel and is pivotally connected at a second end to a second front wheel; and the front wheels are pivotally mounted on supporting suspension arrangements for steering rotation under control of the track rod.   
     
     
         12 . An amphibious vehicle comprising:
 a sit-astride seat,   a planing hull,   at least four wheels, all of which are movable between an extended land mode location and a retracted water mode location, two of the wheels being front steerable wheels, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one of the wheels to drive the wheel,   a speed change transmission giving the vehicle in forward motion on land a plurality of different gear ratios connected between the engine and the driven wheel(s), and a jet connected to the engine to be driven thereby to propel the vehicle on water.   
     
     
         13 . An amphibious vehicle as claimed in  claim 12 , wherein
 all of the four wheels are each pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof.   
     
     
         14 . An amphibious vehicle as claimed in  claim 12 , wherein:
 the speed change transmission comprises a manually operable gearbox and a manually operable gear selection means are provided operable by a driver of the vehicle to select one of the gear ratios.   
     
     
         15 . An amphibious vehicle as claimed in  claim 12 , wherein:
 the speed change transmission comprises an automatic gearbox.   
     
     
         16 . An amphibious vehicle as claimed in  claim 12 , wherein:
 the speed change transmission comprises a continuously variable transmission.   
     
     
         17 . An amphibious vehicle comprising:
 a sit-astride seat,   a planing hull,   at least four wheels, all of which are movable between an extended land mode location and a retracted water mode location, each being pivoted about an axis running fore and aft along the vehicle when moved between the land mode and the water mode locations thereof, two of the wheels being front steerable wheels, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one of the wheels to drive the wheel, and   marine propulsion means to propel the vehicle on water   
     
     
         18 . An amphibious vehicle as claimed in  claim 17 , wherein:
 each road wheel is pivoted through 45° or more during retraction.   
     
     
         19 . An amphibious vehicle as claimed in  claim 17 , wherein:
 the four wheels comprise a front pair of wheels steerable by the handlebars and spaced apart transversely across the vehicle by a first track width when in land mode and a rear pair of wheels spaced apart transversely across the vehicle by a second track width when in land mode; and the planing hull has a maximum beam width which is less than both the first and second track widths.   
     
     
         20 . An amphibious vehicle as claimed in  claim 19 , wherein:
 the first track width is greater than the second track width.   
     
     
         21 . An amphibious vehicle as claimed in  claim 19 , wherein:
 a separate spring and damper assembly is provided for each wheel.   
     
     
         22 . An amphibious vehicle comprising:
 a sit-astride seat,   a planing hull,   at least four wheels, each of which is movable between an extended land mode location and a retracted water mode location, two of the wheels being front steerable wheels, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one of the wheels to drive the wheel, and   marine propulsion means to propel the vehicle on water, wherein:   the planing hull is formed as a single component and the vehicle has one or more deck components all joined to the hull component along a join line which extends around an entire periphery of the vehicle at a level above a water line of the vehicle in water; and   the or at least one of the deck components forms a majority of an upwardly facing surface of the vehicle and is demountable to allow access to the engine located there beneath.   
     
     
         23 . An amphibious vehicle as claimed in  claim 22 , wherein:
 the hull and each deck component is formed of a composite of fibres set in resin and localised areas of at least some of the deck components are provided with fibre reinforcement additional to the fibre reinforcement in a remainder of the component(s) to provide a greater structural strength in such areas, whereby reinforced areas provide load paths for transmission of loading of the vehicle and the load paths extend around an entire transversely viewed periphery of the vehicle to resist torsion loads acting to twist a front part of the vehicle relative to a rear part of the vehicle.   
     
     
         24 . An amphibious vehicle comprising:
 a sit-astride seat,   a planing hull,   at least four wheels, each of which is movable between an extended land mode location and a retracted water mode location, two of the wheels being front steerable wheels of the vehicle, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one wheel to drive the wheel, and   marine propulsion means to propel the vehicle on water, wherein:   the engine is mounted on a frame releasably connected to the hull, the vehicle also comprising a transmission connecting the engine to the driven wheel(s), at least part of the transmission also being mounted on the frame.   
     
     
         25 . An amphibious vehicle as claimed in  claim 24 , wherein:
 a suspension system is provided for the road wheels and the suspension system is also mounted on the frame.   
     
     
         26 . An amphibious vehicle as claimed in  claim 25 , wherein a steering mechanism is connected between the handlebars at the front steerable wheels and the steering mechanism is also mounted on the frame. 
     
     
         27 . An amphibious vehicle comprising:
 a sit-astride seat,   a vehicle body having a planing hull,   at least four wheels, each of which is movable between an extended land mode location and a retracted water mode location, two of the wheels being steerable wheels, which are, at least in the land mode of the vehicle, connected to handlebars which can be operated by a driver to steer the vehicle,   an engine which in the land mode of the vehicle is connected to at least one of the wheels to drive the wheel, and   marine propulsion means to propel the vehicle on water, wherein:   the vehicle body defines a pair of footwell areas spaced apart on both sides of the sit-astride seat with the vehicle body having sill portions positioned laterally outside the footwell areas.   
     
     
         28 . An amphibious vehicle as claimed in  claim 27 , wherein buoyancy chambers are provided in the sill portions of the vehicle.