| US3765368A | 1973-10-16 | |||
| US3831210A | 1974-08-27 | |||
| US3903831A | 1975-09-09 | |||
| US3362373A | 1968-01-09 | |||
| US3421472A | 1969-01-14 | |||
| US4008679A | 1977-02-22 | |||
| US2908241A | 1959-10-13 | |||
| DE1103169B | 1961-03-23 | |||
| US3811793A | 1974-05-21 |
| 1. | Claim 1. A trailer chassis suitable to be coupled to a vehicle in a towing position. Said trailer chassis having the following features: At least two ground engaging wheels. The trailer chassis is structurally so designed and constructed, that it consists of a number of boxes, which are connected to each other with braces and beams and are arranged in such a manner, that the total mass of the trailer chassis plus a specified maximum load rest on and are supported by the road wheels of the trailer chassis for towing behind a vehicle. The volume of the trailer chassis is designed such, that the total mass of the trailer chassis together with a specified maximum load can be moved into water, where it will float with sufficient freeboard to meet a particular requirement. The front and the bottom are suitably shaped to reduce drag and to enhance steering control when moving through the water. Claim 2. A trailer chassis as claimed in claim 1, having internal partitions on both sides to form wheelhousings . A trailingarm suspension with stub axle and wheel is mounted inside each wheelhousing with sufficient space for the wheel to be retracted. Each wheelhousing is made airtight on all sides but open at the bottom. When in the water, the wheelhousing acts like a diving bell. This ensures, that the waterlevel inside the wheelhousing is slightly above the lower edge and well below the water surface on the outside. The suspension bearings are well clear of the water. There is a removable panel to provide access to the suspension and for wheel changing. A second removable panel closes off the bottom of the wheelhousing when in the water, to avoid air from escaping when moving through the water. This panel need not be airtight. Claim 3.. A trailer chassis as claimed in claims 1. and 2., having an independent suspension and stub axle for each wheel. An Air Spring or Air Bag is mounted between each suspension arm and the surface above it. Air being forced into the Air Spring or Air Bag lowers the wheel relative to the trailer chassis. At the desired ground clearance the air valve is closed to maintain the Air Spring or Air Bag at this extension for this load. The Air Spring or Air Bag then acts as a suspension spring, providing shock and vibration isolation between the wheel and the trailer chassis. When air is released from the Air Springs or Air Bags, the wheels will move up into the wheelhousings under the weight of the trailer chassis and its load. The Air Springs or Air Bags therefore act as springs, as well as raising and lowering devices. Claim 4. A trailer chassis as claimed in claims 1. ,2.and 3., having an air supply tube and suitable valve connected to the wheel—housing. A level sensor senses the water level inside the wheel—housing. If air escapes out off the wheelhousing, the water level will rise, causing the level sensor to trigger an alarm or directly cause air to be forced into the wheelhousing, thereby displacing the water to the preset level, ensuring that the bearings stay clear of the water. |
This invention describes a type of trailer which is equipped for towing behind a motor vehicle on land and which can be launched into water in its entirety, including the trailers load. Such an amphibious trailer chassis can be designed for many different purposes.
Applications would include the following:
An amphibious transport vehicle for emergency and rescue services.
A trailer for towing by amphibious cars or trucks.
A chassis for an amphibious caravan.
A watercraft for pleasure.
The amphibious trailer chassis could be built in various sizes and shapes to meet specific requirements.
Amphibious cars and trucks s.re expensive in acquisition and maintenance. This is because some wheels need to be driven and have to be moved for steering.
The wheels of a trailer are not driven, nor do they need to be moved for steering. It is therefore simpler to retract the road wheels in order to keep the wheel bearings out of the water and to reduce drag when moving through the water.
It is the object of this invention to provide a type of amphibious trailer which can be towed behind a vehicle on land while carrying a load, and be capable of being launched into the water in its entirety together with its load.
The road wheels can be retracted, keeping the wheel bearings out of the water. On retrieval from the water the road wheels can be lowered, thereby raising the trailer with its load to a suitable height for towing on the road.
The main features of this invention can be described as follows:
The trailer chassis is structurally so designed and constructed, that it consists of a number of sealed boxes, connected with braces and beams in such a manner, that the mass of the trailer chassis together with a maximum specified load, rests on and is supported by its road wheels for towing behind a motor vehicle.
The displacement volume of the trailer chassis is so designed, that the total mass of the trailer chassis together with a maximum load will float in water with sufficient freeboard to meet a particular requirement.
The bow and the bottom are suitably shaped to reduce drag and enhance steering control in water. There is a facility to mount an outboard motor.
On either side of the trailer chassis there is a hull-shape box over the length of the trailer chassis, near the longitudinal centre there are partitions in each hull, forming a wheel—housing on either side. Each wheel-housing is air tight on all sides except at the bottom, which, is open.
Inside each wheel-housing a trailing arm with a stub axle is mounted, providing sufficient vertical movement for the wheel on the stub axle to be retracted into the wheel-housing. Due to the trailing arm, the wheels are free to move only in a vertical arc.
The vertical movement for retracting and lowering the wheels can be controlled by a screw mechanism, by hydraulic means, or by Air Springs or Air Bags of the type used in the suspension of busses, trucks etc.
Air Springs or Air Bags appear to be the most efficient solution. This is the only solution described here in more detail.
An Air Spring is mounted between each trailing arm and the horizontal surface above it. When air is forced into the Air Springs, the wheels will be lowered relative to the Trailer Chassis. That is, with the road wheels on the ground, the Trailer Chassis will be raised. At the deεired distance from the ground, a valve is closed to maintain the air pressure in the Air spring. These now provide shock and vibration isolation between the road wheels and the Trailer Chassis when being towed behind a vehicle.
When air is released from the Air Springs, the weight of the Trailer Chassis will lower it to the ground. The wheels retract into the wheel-housings to the desired level .
There is a removable panel on each wheel-housing. This provides access to the suspension and wheel for maintenance and wheel change.
It is an important feature of this invention, that the wheel-housings are made air tight on all sides except at the bottom. Since air cannot escape from the wheel-housing, the water level inside the wheel-housing will be slightly above the bottom edge and well below the water surface outside. Suspension and wheel bearings are therefore out of the water.
A removable panel closes off the bottom to avoid loss of air and a rise of the water level in the wheel housing when moving through the water.
A compressed air pipe leads into each wheel-housing. in the event that air escapes out of a wheel-housing, the water level rises, a level sensor, installed in each wheel-housing, triggers an alarm, or automatically releases compressed air into the respective wheel-housing until the desired water level is restored.
This ensures that the suspension arms and wheel bearings are not submersed.
A panel which closes off the wheel-housing under water, can have a shape that will provide a suction effect when moving forward through the water. A one-way valve, installed in the upper part of the wheel-housing, will let ambient air into the wheel-housing, thus automatically maintaining the water level close to the bottom edge.
The launching procedure would be as follows:
The Amphibious Trailer Chassis with its load iε rolled into shallow water and decoupled from the towing vehicle. A brake will hold the trailer in position. The operator opens valves to release air from the Air Springs. Under the weight, the Air Springs are compressed and the Trailer Chassis is lowered until only a small part of the tyres are visible. The Trailer Chassis can then be moved further until it floats. A tension spring in each wheel—housing will keep the wheels up. The bottom panel can the be put in place to avoid loss of air. This however need not be air tight.
Retrieval from the water is in the corresponding reverse εequence. Compressed air for the lowering of the wheels under load can be stored on board the Amphibious Trailer Chassis in a suitable cylinder which can be charged at service stations or by an onboard compressor operating from 12Volts DC.
The enclosed drawings show one possible arrangement of the essential features; and outline a practical shape of the Amphibious Trailer Chassis. Variations are no doubt feasible. It could be made longer and could have more than two wheels.