AU617100B2 - An amphibious trailer chassis - Google Patents

Description

PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE PATE NT OFFICE Short Title: A pplication Num ber TEN DOPA ENTARS Lodged;TNDOLR 1;/i 8 MAR 1-1( :0 ';(Zmplete Specification-Lodged: 00 rO Accepted: 0 0 Lapsed: 0 0 00 P/00/01 1 Form ooRelated Art; 0 00 Name of Applicant; 0 0 0 ~AtiCiress of Applicant: Actual Inventor: Address for Service: Complete Specification TO BE COMPLETED BY APPLICANT Haiis-R-adi Bels 18 Umbango 'Drive Ormea- 4208 ODGED AT ISUB-OFFICE Qrina 20818 OMAR 19f Hans-Radi B els Brisbane 18 Umbango Dlrive Ormeau 4208 for the Invention entitled: An amphibioue trailer chassia.

The following statement Is a full description of this Invention, Including the best method of performing It known to met- Note:- The description Is to be typed In double spacing,, pica type face, In a n area not exceeding 250 mm In depth and 160 mm In width, on tough white paper of goad quality and It Is to be Inserted Inside this farm.

I 469/10-L Printed by C. J, Ttiompsor~, Commnonwealth Oovernment Printer, Canberrat 004040 0 0 04 00 00 0 00 04 00 0 0 0 044,,.

o 0 9.4004 0 0004 00 4 00 00 0 0 0 0 04,a 4 0 O 0 0 00 #0 0 00 0 400 0 000000 0 This invention relates to an amphibious trailer chassis with retractable wheels which is designed for towing behind a motor vehicle on land and can be launched into the water in its entirety, including the trailers load.

This amphibious trailer chassis can support various bodies or structures to suit specific purposes such as: An amphibious transport vehicle for flood rescue operations, an amphibious work platform or an amphibious caravan.

10 It has been found, that amphibious vehicles which are usually self propelled, are expensive in acquisition and maintenance. It appears, that amphi~bious vehicles that are not self propelled, mostly traiierable boats, are not intended~ as transport vehicles. Also the mechanisms for retracting wheels, which have been described so far, appear to be complex and relatively expensive.

It is -the object of this invention to provide an amphibious trailer chassis with retractable wheels, that can be towed with a load by a motor vehicle on land and can be launched with a load into the water. This amphibious trailer chassis can support various bodies or structures to suit specific purposes such as: An amphibious transport vehicle for flood rescue operations, an amphibious work platform or an amphibious caravan and to describe means for retracting the whaels into wheel housings and describe means for keeping the wheel 28 bearings above water when retracted.

C1 This invention describes an amphibious trailer chassis with at least two ground engaging retractable wheels, which can be towed with a load by a motor vehicle and which can be launched in its entirety including its load, into the water. The invention can be the chassis for trailers of various configuration, such as an amphibious caravan. The wheels are retracted on entering the water, thus avoiding that the wheel bearings are submerged. The load carrying deck is flat and is entirely above the water line, with sufficient free board to operate with a 4 specified load in protected waters. When retrieving from the water, with its load, the wheels can be lowered again for transport on land. The longitudinal structural members on both sides of the amphibious trailer chassis o.o° are large-crossection box girders in the shape of two boat hulls. Together with the centre section an So oessentially flat deck is formed that is well above the oo>' water line when the amphibious trailer chassis is afloat.

Near the longitudinal centre of the two boat hulls there are partitions which form a wheel housing on either side.

These housings are air tight on all sides accept at the bottom. Inside each wheel housing a trailing arm suspension is installed with a stub axle unto which a wheel is mounted.

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4 I ao 4 I 4 p The trailing arm suspensions which are independent from each other, permit vertical movement of the wheels to absorb road shocks and for retraction and extension. This vertical movement is controllhd by a single Air Spring mounted on each trailing arm.

It is an important feature of this invention that the wheel housings are air tight all around accept at the bottom. Each wheel housing therefore acts as a dliving bell, which means that the water level inside the wheel housing is considerably lower than the water level outside, provided that the volume of air is maintained inside the wheel housing.

A further feature of the invention is a water level sensing switch installed inside each wheel housing, This senses the level of water inside the wheel housing when the trailer chassis is afloat and controlles air flow from a source of compressed air, which is installed on board such that if the water level inside one of the wheel housings rises above a predetermined level, c9mpressed air is introduced into the wheel housing to lower the water level therein to a preset level, thus keeping the wheel bearings above the water when the wheels are retracted in the wheel housings.

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The operation of the invention can be described as follows: The amphibious trailer with a load is towed by a motor vehicle on the road. To launch the amphibious trailer into the water, it is moved to the edge of the water on a ramp or a beach, a valve is opened to release the air from the Air Springs and the wheels retract under the mass of the amphibious trailer until the suspension hits the stop. A small part of the tyres will remain outside the hull, permitting the trailer to be wheeled in to the water until it floats. It is then disconnected from the towing vehicle. The outboard motor can then be lowered and started. As a boat, the amphibious trailer can transport a specified load safely in protected waters.

o o 44o To retrieve the trailer from the water, it is moved towards land until the hulls or the wheels touch a 0 4 4 bottom. An air compressor, which is installed on the trailer is switched on to inflate the Air Springs. This lowers the wheels to lift the hulls off the ground and further to the desired ground clearance. The corresponding valves are then closed off to maintain the pressure in the Air Springs. The amphibious trailer is then connected to the towing vehicle and it can be towed on the road again. As described earlier, the wheels are inside air tight wheel housings. To provide access for changing wheels and for checking the

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suspension, a removable panel is provided in each wheel S 28 housing. This panel has an air-tight seal.

A particular embodiment of the invention will now be described with reference to the accompanying drawings.

Fig.l is a plan view of the amphibious trailer chassis with the deck removed for clarity. The hull shapes 1. on each side of the trailer chassis are large crossection box girders which are the longitudinal structural members. Near the longitudinal centre the wheel housings 4. are located. The centre section 2 is fixed to the hulls 1 and forms the centre bow, to which 10 the removable towing hitch 5 is connected. The cross members 3 are light-gauge beams which provide lateral stability and support the deck. Fig.2 is a side elevation, showing the general shape of the hulls and a portion of a wheel 6. Fig.3 shows an external rear r o g 4° elevation on the left hand side and a section through the 4 wheel housing 4 on the right. It shows the shape of the centre section 2 and the cross members 3, which connect :s the hulls on either side together, thus providing lateral rigidity and support for the deck. It also shows one of the air springs 7 mounted on the trailing arms 8 with axle 9 and one wheel 6. Fig.4 shows a horizontal section through the wheel housing The position of the shock absorber 10 can be seen on a plate which is mounted across the trailing arms 8. Fig.5 shows a vertical section of the wheel housing 4 from the inside, with the wheel 6 in the normal position for travel on land, 1 ,~M

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The trailing arms 8 are mounted on pivot pins 11, which fix the trailing arms 8 in the horizontal plane, but allow vertical rotation to absorb road shocks and allow for the retraction and extension of the wheel 6, which will depend on the amount of inflation of the Air Spring 7. The position of the shock absorber 10 is indicated.

The shock absorber 10 dampens the oscillations of the trailing arm 8, thus providing a better towing performance. Fig.6 shows the same section as fig.5, but with the wheel 6 retracted as it is when the amphibious Strailer chassis is in the water. The wheel housing 4 is air tight all around, but open at the bottom. The wheel housing 4 acts like a diving bell, keeping the water level inside the wheel housing 4 well below the water .s surface at the outside provided the volume of air is a a maintained inside the wheel housing 4. A water level 0444 sensing switch is installed inside each wheel housing 4.

This senses the level of water inside the wheel housing 4 when the trailer chassis is afloat and controlles air flow from a source of compressed air, which is installed on board, such that if the water level inside one of the wheel housings 4 rises above a predetermined level, compressed air is introduced into the wheel housing 4 to lower the water lrel therein to a preset level, thus keeping the wheel S:earings above the water when the wheels are retracted in the housings. The level sensing '1t4 switch is not shown in the drawings, because different S commercially available types can be used.

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