GB2478395A - A two wheeled planing amphibian with retractable wheels - Google Patents

Abstract

A two wheeled planing amphibian 10 has a hull 20, bow 24, front wheel 30 and rear wheel 40. Front suspension 32 and rear suspension 42 are retractable, separately or simultaneously. Front wheel 30 may retract vertically or rotationally. Steering is by handlebars 50, link 54, and forks 36. Front wheel 20 may be located outside the hull in both protracted and retracted positions. The underside of the hull 20 is continuous in both land mode and marine mode along and across its centreline from the bow to the rearmost underside point on the hull along the centreline; or from the forwardmost underside point on the hull when it is planing at its lowest speed to the rear. There are no wheel closures attached to the hull. A wheel bay (22, Fig 2a), which is open at its top side, may be provided to allow rear wheel retraction.

Description

niphibian The present invention relates to a two wheel amphibian.

A number of arrangements foramphibians having two wheels have been proposed. For e,ample as known from GB 2 254 831 to Buchanan or, US 6 540 69 to Gong. In both of these known arrangements the front wheel is arranged to retract into a compartment in thehu11 which is closed by a retractable wheel cover in order to enable planing of the amphibian. Without such wheel covers, the water would impact on the rearward side of the wheel compartment thereby dramatically increasing drag and preventing planing.

However, the use of wheel covers Jias been found to be problematic since the mechanisms which actuate the covers, and the covers themselves, can beqome jammed with mud or weeds. Furthermore, because of t1e high impact forces experienced on the underside of tle hull during planing, wheel covers can easily be lost o broken.

In an alternative known arrangement, for example as disclosed in DE 198 31 324 to Lehrberger, the hull is arranged to split along its centreline to reveal both the front and rear wheels. As above, this arrangement is * 25 susceptible to becoming jammed wi1h mud and weeds. In S.....

* * addition, this arrangement resu1t in a cumbersome and difficult to ride configuration in land mode.

The present invention provids a two wheel planing :. 30 amphibian for use on land and watr, comprising: a hull; a * . front wheel mounted to the amphibiian by a front suspension assembly; a rear wheel mounted to the amphibian by a rear suspension assembly; at least one wheel retraction mechanism for moving the front and rear whels between a deployed position for use of the amphibian on land, and a retracted position for use of the amphibian on water; wherein the front wheel is located outside the hull in both the deployed and retracted positions.

The arrangement of the prese4t invention is advantageous since there is no recjuirement for moveable hull components which may become jamrne4. Furthermore, because there is no need for wheel covers, there is less likelihood of hull failure.

The present invention will now be described with reference to the following figures in which: Fig 1 shows a schematic elevation of a two wheeled amphibian in its land mode configiration; Fig 2 shows a schematic elevtion of the two wheeled amphibian of Fig 1 in its marine rrode configuration; Fig 2a shows a schematic plar view of the stern of the amphibian of Fig 1.

Fig 3 shows a first alternat±ve marine mode configuration; and * 25 Fig 4 shows a second alternaive marine mode * * configuration ** * Figure 1 shows an amphibian]0 which has a hull 20, and front and rear wheels 30, 40. Th front and rear wheels 30, :. 30 40 are shown in their deployed poition for use of the * amphibian on land 14 in its land node.

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The front wheel 30 is mountec to the amphibian 10 by a front suspension assembly 32, andthe rear wheel 40 is mounted to the amphibian 10 by a rear suspension assembly 42. A steering assembly 52 compr4sirig handle bars 50 and steering connection link 54 is oprative1y connected to the front suspension 32 to allow a ricer to steer the amphibian 10. A seat 12 is also provided.

The front suspension 32 compiiises a front connection link 38 which is connected to front fork 36 at pivot 34.

The front connection link 38 passes through the hull 20 via watertight sealed bearings (not shown) which allow the front connection link 38 to rotate but 4hich seal the hull 20 against water ingress. The front wheel 30 is carried for rotation by the front fork 36.

The rear suspension 42 comprises a rear trailing arm 46 which is mounted at pivot point 4, to the amphibian 10. The opposite end of the trailing arm carries rear wheel 40 for rotation.

The front and rear suspensiors are each provided with a wheel retraction mechanism (not sown) which may be arranged to retract both the front and rea wheels at the same time.

* 25 Alternatively, the wheel retracticn mechanism comprises a S.....

* front wheel retraction assembly arid a rear wheel retraction : assembly so that the front and rer wheels may be deployed or retracted independently. In ore example wheel retraction is achieved by the use of hydraulijc struts which may form part of the suspension systems. 1he struts may be ::.::j constructed according to the Appliicant's patent, US 6 886 837 B2, and may have an interrnedite pivot mounting similar to that disclosed in US 6 945 832 B2.

Figure 2 shows the amphibian 10 with the front and rear wheels 30, 40 in the retracted poition for use of the amphibian on water 16 in its marire mode.

As can be seen, the front whe1 30 has been retracted to a position in front of the bow 24 and above the waterline 16 by the articulation of the frort fork 36 about pivot 34.

Because the front wheel 30 must nct foul the bow 24 as it moves, or while it is at rest, th front fork 36 is provided with a hydraulically controlled tlescoping rod with extends as the front wheel 30 is retracted. This telescoping rod may form part of the front suspension. The front wheel 30 is held in this position by the rtraction mechanism.

The rear wheel 40 is retractd to a position above the waterline by articulation of the rear trailing arm 46 about pivot point 44. The rear wheel 40j is held in this position by the retraction mechanism which ttay be locked in place, for example, by a strut locking peg according to GB 2 397 344 B. * 25 The hull 20 comprises a rear heel bay 22 located in ***** * * the stern (Fig 2a) . In this example, the rear wheel 40 is *:*. partially positioned within the rear wheel bay 22 in both the land mode and marine mode configurations. In an alternative example (not shown) th hull may extend over the :. 30 rear wheel in the land and/or marike mode configurations.

* Alternatively, the rear wheel may e located aft of the *..*.* * * stern 23 in the land and/or marinel mode configurations.

Whilst in the above the termiand mode is generally associated with the wheels in the deployed position, and mariri mode is generally associatd with the wheels in the retracted position,\ it will be understood that the wheels may be deployed when the amphibiar is in water. For example, on entry or exit of the amphibian into or out of the water.

An alternative arrangement o a two wheeled amphibian 10' is shown in Figure 3. In thi example, the front fork 36' is shaped so as to fit over tIe bow 24 when the front wheel 30 is in the retracted posiion.

A still further example of atwo wheeled amphibian 10'' is shown in Figure 4. In this example the front wheel 30 is mounted to the amphibian 10 by chassis assembly 58 which has a projection portion 56 extending over the bow 24. The front wheel 30 is constrained to i4ertical deployment and retraction by the front suspensior (not shown) Alternatively, the front wheel ma be mounted on an articulating fork as described above with reference to Figures 1 and 2.

Each of the amphibians 10, id', 10'' described above ***.** * : 25 comprise a power unit, such as a petrol or diesel engine, S.....

* which is adapted to drive the ampHibian in both its land *:*. mode and marine mode. The power init may drive one or both of the wheels in land mode, and my also drive a water propulsion device, such as a water jet drive or propeller, :. 30 in marine mode. Alternatively, the water drive power unit and land drive power unit may be eparate. Suitable power take off(s) and gearing are provi4ed.

Although the front and rear heels have been described in the above as single unitary coriponents, it should be understood that the front and/or tear wheel may comprise two or more individual wheels mountedin close proximity on a common axle such that the two or more wheels effectively form a single wheel.

Any of the features of any eample may be combined with any other feature from any of the examples. * S

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Claims (4)

1. CLAIMS1. A two wheel planing amphib&ar for use on land and water, comprising: a hull; a front wheel mounted to theamphibian by a front suspension assembly; a rear wheel mounted to the ¶mPhibian by a rear suspension assembly; at least one wheel retractiorti mechanism for moving the front and rear wheels between a dployed position for use of the amphibian on land, and a retr,cted position for use of the amphibian on water; wherein the front wheel is located outside the hull in both the deployed arid retracted p4sitions.
2. 2. A two wheel planing am*phibiar for use on land and water, comprising: a hull; a front wheel mounted to the amphibian by a front suspension assembly; a rear wheel mounted to the rnphibian by a rear suspension assembly; at least one wheel retraction mechanism for moving the front and rear wheels between a ddployed position for use of I.....* 25 the amphibian on land, and a retracted position for use of * **..* * 1 the amphibian on water; *. : wherein the underside of the hull is continuous in both * land mode and marine mode along ard across its centreline from the bow to the rearmost undeside point on the hull along the centreline. * * .
3. 3. A two wheel planing amphibiar! for use on land and water, Comprising: a hull; a front wheel mounted to the amphibian by a front suspension assembly; a rear wheel mounted to the amphibian by a rear suspension assembly; at least one wheel retraction mechanism for moving the front and rear wheels between a dployed position for use of the amphibian on land, and a retrcted position for use of the amphibian on water; wherein the underside of the hull is continuous in both land mode and marine mode along ard across its centreline from the forwardrnost underside point on the hull which intersects the waterline when the amphibian is planing at its lowest speed, to the rearinost underside point on the hull along the centrelinie.
4. 4. A two wheel planing amphibiar for use on land and water, comprising: a hull; a front wheel mounted to the amphibian by a front suspension assembly; a rear wheel mounted to the afrnphibian by a rear * : 25 suspension assembly; S.....* at least one wheel retractions mechanism for moving the * front and rear wheels between a deployed position for use of * .: the amphibian on land, and a retracted position for use of the amphibian on water; wherein there are no wheel cvers attached to the * underside of the hull.*S.SSS S * Amendment to the claims have been filed as followsCLAIMS1. A two wheel planing amphibian for use on land and water, comprising: a hull; a front wheel mounted to the amphibian by a front suspension assembly; a rear wheel mounted to the amphibian by a rear suspension assembly; at least one wheel retraction mechanism for moving the front and rear wheels between a deployed position for use of the amphibian on land, and a retracted position for use of the amphibian on water; wherein there are no wheel covers attached to the underside of the hull.SI..... * SS*5SS*SI * **SI S S.. S -I..S I...