AU2018398234A1

AU2018398234A1 - Transport apparatus

Info

Publication number: AU2018398234A1
Application number: AU2018398234A
Authority: AU
Inventors: William Mark Tarahina Groves
Original assignee: Innovative Transp Ltd
Current assignee: Innovative Transport Ltd
Priority date: 2017-12-29
Filing date: 2018-12-21
Publication date: 2020-07-16
Also published as: AR114068A1; WO2019132673A1; TW201930106A

Abstract

A trailer for hauling a load, the trailer comprising a first dolly having at least one axle, the first dolly configured to be pivotable relative to the trailer a drawbar connected to the first dolly to connect to a towing vehicle, a second dolly having at least one axle, the second dolly configured to be pivotable relative to the trailer; and a telescoping stinger connecting the first dolly and the second dolly, configured to cause the second dolly to pivot depending on pivoting of the first dolly.

Description

TRANSPORT APPARATUS

This invention relates to a steerable trailer and a tank for the transport of moveable substances including fluids.

BACKGROUND

Tanks are used on trucks and trailers to transport liquids such as milk and petrol. One particular issue is that the liquid in such tanks 'sloshes' inside the tanks, causing instability which creates safety problems. Liquid sloshing negatively influences the directional dynamics and the safety of trucks and trailers.

Truck trailers, particularly long trailers, sometimes struggle to navigate winding and/or narrow roads. This increases transportation costs (increased tire wear, maintenance and/or fuel costs) and can be inefficient if a larger number of smaller vehicles have to be used or alternative less windy roads used resulting in increased distances covered.

The present invention may provide an improved steerable trailer and a container for the transport of fluids or at least provide the public or industry with a useful choice.

SUMMARY

According to one example embodiment there is provided a tank for transporting liquids comprising: a tank for receiving liquids; and at least one plate in the tank rotatable from a first position in which the tank is a single chamber and a second position that divides the tank into a first sub chamber and a second sub chamber.

Preferably the at least one plate moves from the first position to the second position when the level of the liquid in the tank raises above the position of the plates in the second position.

Preferably the at least one plate moves from the second position to the first position when the level of the liquid in the tank drops to a level just above the position of the plates in the second position. Preferably the at least one plate is moveable by a mechanical level detection mechanism. Alternatively, the at least one plate is moveable by a controller.

Preferably the controller is operational to move the at least one plate to either the first position or the second position irrespective of the level of fluid.

Preferably the at least one plate in the second position substantially seals the tank into two sub chambers.

Preferably the at least one plate has an axis of rotation parallel with the tank elongated axis. Preferably the first sub chamber is between 25% and 45% of volume of the tank.

More preferably the first sub chamber is between 30% and 40% of volume of the tank.

Even more preferably the first sub chamber is approximately 1/3 of volume of the tank. Preferably the tank is mounted on a trailer.

Alternatively, the tank is mounted on a truck chassis.

Preferably the tank is a milk tank.

Preferably the tank is cleanable when the at least one plate is in the first position.

Preferably the at least one plate is two plates.

According to another example embodiment there is provided a trailer for hauling a load, the trailer comprising: a first dolly having at least one axle, the first dolly configured to be pivotable relative to the trailer; a drawbar connected to the first dolly to connect to a towing vehicle; a second dolly having at least one axle, the second dolly configured to be pivotable relative to the trailer; and a telescoping stinger connecting the first dolly and the second dolly, wherein pivoting of the first dolly causes the second dolly to pivot.

Preferably the second dolly having a locked configuration in which the second dolly is non- pivotable and an unlocked configuration in which the second dolly is pivotable.

Preferably the locked configuration is speed controlled.

Preferably locking is activated at 60km/hr.

Preferably the locked configuration is activated by a controller.

Preferably the locking mechanism is a plurality of pins.

Preferably the load is a tank.

Preferably the tank is a milk tank.

Alternatively, the load is an elongated object

Alternatively, the load is a container.

Alternatively, the load is at least one log.

Alternatively, the load is at least one power pole.

Preferably the first dolly is a front dolly.

Preferably the second dolly is a rear dolly.

Preferably the first dolly has at least two axles.

Preferably the second dolly has at least two axles.

Alternatively, the second dolly has at least three axles.

Preferably the towing vehicle is a prime mover.

Alternatively, the towing vehicle is a tractor. Alternatively, the towing vehicle is an intermediate trailer.

Preferably the intermediate trailer has a second pivotable front dolly, a second pivotable back dolly, and a second telescoping stinger connecting the second pivotable front dolly and the second pivotable back dolly, wherein pivoting of the second pivotable front dolly causes the second pivotable back dolly to pivot.

Preferably the trailer has a chassis to which the load is secured, the first dolly pivotably connected to the chassis towards a front end of the chassis and the rear dolly connected to the chassis towards a rear end of the chassis.

Preferably the load does not significantly overhand or canteliver over the first or the second dolly.

According to a further example embodiment there is provided a trailer for hauling a load, the trailer comprising: a chassis to which the load is secured, the chassis having a front end and a rear end; a front dolly having at least one wheel set, the front dolly having a front end and a rear end coaxial with the chassis front end and rear end; a front bolster mounted over the front dolly and pivotably connected to the chassis towards the front end of the chassis; a drawbar connected to the front end of front dolly, the drawbar connecting the trailer to a towing vehicle; a rear dolly having at least one wheel set, the rear dolly having a front end and a rear end coaxial with the chassis front end and rear end; an articulated and telescoping stinger connecting the rear end of the front dolly and the front end of the rear dolly; and a rear bolster mounted over the rear dolly, the bolster connected to the chassis towards the rear end, the bolster having a locked configuration in which the bolster is fixedly connected to the chassis to move in unison therewith and an unlocked configuration in which the bolster is rotatably connected to the chassis wherein in the unlocked configuration the articulation of the front dolly causes a steering effect on the rear dolly.

According to another example embodiment there is provided a trailer for hauling a load, the trailer comprising: a chassis to which the load is secured, the chassis having a front end and a rear end; a front dolly having at least one wheel set, the front dolly having a front end and a rear end coaxial with the chassis front end and rear end, the front dolly pivotably connected to the chassis towards the front end of the chassis; a drawbar connected to the front end of front dolly, the drawbar connecting the trailer to a towing vehicle; a rear dolly having at least one wheel set, the rear dolly having a front end and a rear end coaxial with the chassis front end and rear end, the rear dolly connected to the chassis towards the rear end, the rear dolly having a locked configuration in which the rear dolly is fixedly connected to the chassis to move in unison therewith and an unlocked configuration in which the rear dolly is rotatably connected to the chassis; and an articulated and telescoping stinger connecting the rear end of the front dolly and the front end of the rear dolly, wherein in the unlocked configuration the articulation of the front dolly causes a steering effect on the rear dolly.

It is acknowledged that the terms "comprise", "comprises" and "comprising" may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, these terms are intended to have an inclusive meaning - i.e., they will be taken to mean an inclusion of the listed components which the use directly references, and possibly also of other non-specified components or elements.

Reference to any document in this specification does not constitute an admission that it is prior art, validly combinable with other documents or that it forms part of the common general knowledge. BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated in and constitute part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description of embodiments given below, serve to explain the principles of the invention, in which:

Figure la is a cross-sectional end view of a container according to a first embodiment; Figure lb is a cross-sectional side view of container of Figure la;

Figure lc is a cross-sectional end view of a tank;

Figure Id is another cross-sectional end view of a tank;

Figure le is another cross-sectional end view of a tank;

Figure 2 is a side view of a towing vehicle and trailer according to a second embodiment;

Figure 3 is a perspective view of a trailer;

Figure 4 is another perspective view of the trailer of Figure 3;

Figures 5a-h are bottom views of trailers positioned at different steer angles;

Figure 6 is a diagram showing movement of a connection;

Figure 7a is a detailed view of a connection;

Figure 7b is a side view of the connection of Figure 7a;

Figure 8 is a locking mechanism; and

Figure 9 is a further locking mechanism.

DETAILED DESCRIPTION

When liquid is transported inside a tank by truck and the tank is not full, the liquid will slosh (move) around as the truck/trailer turns, accelerates and/or brakes. The sloshing can lead to instability during cornering or braking, which may result in the driver having to reduce speed more than would otherwise be necessary or in the worst case it may result in a jack-knifing, accident. The system according to a first embodiment may minimise the effect of liquid sloshing, thus increasing safety of the truck/trailer.

Referring to Figures la to le a tank 100 for receiving liquids is shown. The tank 100 in the embodiments shown in Figures la and lb has a substantially ovular cross section (though any other suitable cross section may be used) and sits on a vehicle chassis 102.

The tank 100 includes two plates 104 pivoted on pivots 106. The first plate 104a pivots on a first pivot axis 106a, and the second plate 104b pivots on a second pivot axis 106b. The plates 104 have axes of rotation substantially parallel to the longitudinal axis of the tank 100. The plates 104 pivot between a first open position (shown by the dashed lines) and a second closed position (shown by the solid lines). In the first (open) position the plates 104 are positioned substantially upright, and in the second (closed) position, the plates 104 are positioned substantially horizontally.

The plates 104 run along the length of the tank 100, as shown in Figure lb. Thus, in the first open position the tank 100 is a single chamber and the second closed position divides the tank 100 into a first sub chamber 150 below the plates 104 and a second sub chamber 160 above the plates 104.

The plates 104 seal the interior of the tank 100 such that contents of the tank 100 cannot freely pass through the division. The plates may seal because of friction or because a suitable seal such as rubber or plastic is used. When the plates 104 are in the second substantially vertical position, liquid within the tank 100 is free to flow to any part of the tank 100.

This system minimises the sloshing effect of liquids inside the tank 100 by dividing the tank 100 into two chambers once there is enough liquid to fill the first sub chamber 150 thus securing the liquid within the first sub chamber 150 and eliminating any sloshing effect for that volume of liquid.

As illustrated in Figure lc the volume of liquid 170 inside the tank 100 is small, and any sloshing would be minimal. When the level of liquid 170 is at the level of the plates 104 as illustrated in Figure Id the plates 104 seal liquid 170 within a bottom sub chamber 150 such that the liquid 170 is unable to slosh. As there is little or no liquid 170 in the top chamber 160 the amount of sloshing is minimal.

When more liquid is added as illustrated in Figure le the volume of liquid inside the tank 100 is above the level of the plates 104, which are in a closed position. The plates seal some of the liquid 170 within the bottom sub chamber 150 such that the liquid 170 in the sub chamber 150 is unable to slosh. As the volume of liquid 170 in the top chamber 160 is small, again, the amount of sloshing is minimal.

Plates

In the described embodiment, two plates 104 are shown, however it is envisaged that in other embodiments, more or fewer plates may be included. For example, a single plate may be pivoted on one side of the tank to move between open and closed positions. In other embodiments, further plates may be included which divide the tank into three or more sub chambers. Further it is envisaged that in other embodiments the single plate running the length of the tank 100 may be two or more plates, the join between the plates being sealed in the second position.

Closing the plates

The plates 104 close when the content in the tank 100 completely fills the first chamber 150. This minimises the fluid located within a tank 100 which is subject to the acceleration that arises from the movement of the tank as the fluid within the first chamber 150 is substantially contained by the plates 104.

Plates 104 may be manually movable, moveable by a mechanical level detection mechanism, or moveable by a controller. A controller may be operational to lock the plates 104 in either the first or second position irrespective of the level of fluid. The plates 104 may be moved by an hydraulic or electric actuator or other suitable device. Pivots

In the shown embodiment, each plate 104 is mounted inside the tank on two pivots 106, each pivot axis parallel to the longitudinal axis of the tank 100. Each pivot 106 includes a mounting at the front end of the tank and another at the rear of the tank, however additional pivots may be included. The two plates 104 are mounted on the same horizontal plane inside the tank 100 and each plate 104 has dimensions to cover half of the horizontal width of the tank 100 at the height of the plates 104 in the tank 100. Alternatively, as noted above one plate to cover the horizontal width of the tank 100 at the height of the plates 104 in the tank 100 may be used.

Position of Plates

Closed position: In the shown embodiment, the plates 104 are in one embodiment installed at a height such that when the plates 104 are closed, the first chamber 150 has a volume less than half the total volume of the tank 100. The plates 104 may be positioned within a tank 100 such as the first sub chamber 150 has between 25% and 45% of volume of the tank 100. In other embodiments, the first sub chamber 150 has between 30% and 40% of volume of the tank 100, and in yet another embodiment the first sub chamber 150 has approximately 1/3 of volume of the tank 100.

Open position: In the shown embodiment, in the open position of the plates 104 the plates 104 rest against each other, and are substantially erect. However other positions that provide for easy access to the bottom of the tank 100 for cleaning the tank 100 may be utilised.

Use Cases

One or more embodiments may prove useful in any application in which any moveable substance is transported, and particularly in applications where the volume of substance within a tank varies over time. Tanks may be mounted on a trailer, or on a truck chassis for transportation by a vehicle. Depending on the substance different storage vessels may be used. In other embodiments, the tanks may be mounted in a container for transport by road, rail or sea.

In scenarios in which the amount of liquid within the tank increases during a pickup route, the plates 104 may move from the open position to the closed position when the level of the liquid in the tank raises above the position of the plates 104 in the closed position. For example, in a milk tanker which collects milk from different locations until a tank 100 is filled, the plates 104 may move from the open position to the closed position when the level of milk within the tank 100 reaches the level of the pivots 106.

In scenarios in which the amount of liquid within the tank 100 decreases during a delivery run, the plates 104 move from the closed position to the open position, when the level of the liquid in the tank 100 drops to a level just above the position of the plates 104 in the second position. For example, in a fuel delivery container which delivers fuel to different locations, the plates 104 may move from the closed position to the open position when the level of fuel within the tank 100 drops below the level of the pivots 106.

Advantages

There is thus provided a fuel-transporting container with improved safety. Multiple sub chambers are formed within a single container, and liquid cannot easily move between the chambers when plates 104 are closed. When the plates are closed to create the lower container 150 liquid under the plates 104 is unable to slosh, and thus enhances the stability of the transporting vehicle. In the open position, cleaning of the tank 100 is simplified, as the open position provides clear access to the bottom of the tank 100.

TRAILER APPARATUS

According to a second embodiment, a trailer with improved turning capabilities is provided. Tanker truck trailers usually have a large turning radius due to their large size, making it difficult or even impossible to run on winding and/or narrow roads. The second embodiment provides a tanker truck trailer which reduces the turning radius of tanker truck trailers. While described with reference to a tanker truck the trailer design is equally applicable to other large and long loads.

Effectively in this scenario with relative increase in horsepower to weight ratio of tow vehicle further trailers can be connected to form further configurations maintaining performance dynamics. The second embodiment can be applied to single tyre axles. However this configuration is significantly restricted in load carrying capacity and is may be subject to regulatory restrictions depending on the jurisdiction. For most applications, multi-axle dollies are preferred.

The connecting points for tow vehicle to trailer and subsequent trailers employs a simple tow ball connection. This connection is called a freedom joint connector which allows a trailer to move in any direct angle relative to the horizontal or vertical axis of the tow ball connector.

At the point of connection, a force called tremor is created and increases with speed and load increase.

The greater number of trailers increases the number of freedom joints in the overall configuration thus increasing tremor and with the increase in speed results in where the trailers begin to fish tail (rearward amplification) in all directions ultimately causing an effect known as knotting. Knotting may be undesirable in some applications.

The second embodiment may avoid freedom connection points anywhere in its design and uses ring feeder connectors instead, which allows for multi-trailer configurations to be operated at safe speeds relative to loading capacities and conditions.

Referring to Figures 2 to 9 a trailer 201 is shown having two dependently steerable dollies connected by a telescopic, pivotal connection, the trailer 201 can follow the track of a towing vehicle 203 much more closely. Thus, the second embodiment increases the range of roads which the truck trailers can be used on.

The trailer 201 is drawn by draw bar 206 connected to a towing vehicle 203 and includes a chassis 212 carrying a tank. The trailer 201 includes first dolly 210 including a set of axles 270. The first dolly 210 is pivotally connected to the chassis 212. The first dolly 210 when the vehicle is towed in a forward direction is the front dolly. The first dolly 210 is connected to the chassis 212 towards a front end of the chassis 212 which connects to the towing vehicle 203 via the draw bar 206. The trailer 201 also includes a second dolly 220 including axles 260, which when the vehicle is towed in a forward direction is the rear dolly. The second dolly 220 is connected towards a rear end of the chassis 212. The second dolly 220 is also pivotally connected to the chassis 212. In the shown embodiment, the front dolly 210 has two axles 270, and the rear dolly 220 has three axles 260, however the invention is not limited in this respect. Any suitable number of axles may be provided on the front and rear dollies, including one, two or three axles on either dolly.

In traditional trailers, the first dolly 210 is able to rotate about the chassis 212 allowing it to be steered by the tow arm connected to the towing vehicle 203. The second dolly 220 is fixed relative to the chassis hence the wheels attached to the second dolly 220 turn with the rest of the trailer 201.

However, in the second embodiment both the first dolly 210 and second dolly 220 are rotatable. The first dolly 210 is pivotally connected to the second dolly 220 by a stinger 250.

The stinger 250 connecting the first dolly 210 with the second dolly 220 steers the second (rear) dolly 220 by the rotating motion of the first dolly 210. The stinger connection 250 causes the rear dolly 220 to be steered in the opposite direction as the front dolly 210, causing the trailer 201 turn in a smaller radius compared the turning radius when the rear dolly 210 is non pivotable. The stinger 250 is rigidly connected to the rear of the first dolly 210. A telescopic (extendable) arm 255 connects the stinger 250 to the front of the second dolly 220. A connection 258 pivotally connects the stinger 250 to the telescopic arm 255. The connection 258 joins the first 210 and second 220 dollies such that when the first (front) dolly 210 is steered in one direction the connection 258 steers the second (rear) dolly 220 in the opposite direction, thus reducing the turning circle of the trailer 201.

In Figure 5a, the first dolly 210 and second dolly 220 are both aligned with the chassis 212. In Figure 5b to Figure 5h, the first dollies 210 are rotated to a progressively greater extent. The figure progression shows that when the rotation angle of the first dolly 210 increases, 1) the rotation of associated second (rear) dollies 220 increases in a direction opposite to the rotation of the first dolly 220 and 2) the telescoping arms 255 increases in length. Thus, the second (rear) dolly 220 rotates oppositely and proportionately to rotation of the first (front) dolly 210.

The Stinger 250 is constructed with two flat plate high tensile steel fixed to each side of the front dolly chassis rails with high tensile 20mm bolts. A 20mm thick cross plate is welded between side chassis plates to fit heavy duty ring feeder receiver. The stinger is a 150mm x 25mm high tensile steel box section. It is approximately 0.5-Bm long, for example it may be lm long. Depending on the height of the front dolly chassis rails, the Stinger 250 may be angled downward to provide the telescopic arm 255 with a relatively flat range of motion.

The telescopic arm 255 is a slide pole 134mmxl5mm box section high tensile steel. It may telescope between a length of 2 and 7m, for example between 2.5 and 5m, depending on the application requirements and the length of the trailer.

The connection 258 is a towing eye connector or towing ring feeder that is housed inside the Stinger 250 box section 150mm x 25mm high tensile steel.

Alternatively Figures 7a and 7b show an example pivotal connection 258 is a cast iron tow ball 259 pivotable inside a cast iron ball mount 257 lined with a Teflon bush 253.

In order to avoid any significant weight from the load being cantilevered over the dollies (resulting in knotting) it may be desirable to locate the front dolly as close as possible to the front of the trailer and the rear dolly as close as possible to the rear of the trailer. For an approximately 8 meter long trailer (as shown in Figure 2) the dollies may be located at 5.5m centre to centre, the front dolly centre being 1.250m from the front of trailer and the rear dolly centre being 1.935m from the rear of trailer.

Each dolly includes multiple axles, with each having four high impact steel embedded tyres with high force impact air bag componentry. This may reduce potential failure in extreme conditions enabling the design to significantly reduce tyre roll and side impact force. The greater number of axles reduces road pavement wear. For example the trailer 201 may use a high tension stiffness air bag, with a SL9 axle having disc brakes, twin tyre either side, each tyre carried on 8 stud heavy duty rims on trailing arm fitment. The tyres maybe Goodyear Steel Belt 22R. These tyres may be steel belted walls for high impact roll tyre slippage and drag resistance.

The telescoping stinger may allow the trailer to follow the towing vehicles tow path significantly reduces off-tracking , wheel drag and tyre roll without affecting its normal Sweep Path (SP). The angles of enabled positive turning temporarily increases the trailer width thus increasing it's stability or Static Roll Over Threshold (SRT) simultaneously reducing the effects of Dynamic Load Transfer Rate (DLTR) in terms of tyre roll and side transverse forces created during speed in curves and adverse camber.

The trailer dollies cannot over ride one another as the dollies are both connected to the chassis with active heavy-duty ball race turn tables designed to absorb adverse forces in extreme road conditions and temperatures. Both dollies are restricted to turning initiated by the tow vehicle controlled ring feeder connector through a triangular pull bar connected with pins to the front dolly then transferred to the rear of the front dolly fitted with a controlled ring feeder as a direct positive transfer of controlled initiation to turn the rear dolly in an opposite direction to the front dolly.

Load placement in a truck trailer configuration is a critical factor where a sixty/forty percent ratio may be used (depending on the application requirements) where 60% of load is placed on the tow vehicle and 40% is placed on the trailer.

The stinger trailer will have a total of 40% distributed by axle proportion as 15% over front dolly and 25% over rear dolly. This equates to 75% of the load being forward of the trailer centre eliminating the ability for the rear dolly to override the front dolly.

Referring to Figure 6 arrow F shows the direction of movement of the trailer 201, towards the towing vehicle 203. Point E shows the connection position when the tow vehicle and trailer are aligned. Arrow A shows the direction the connection travels when the two vehicle turns right, and Arrow B shows the direction of the connection travels as the vehicle turns left. As the connection moves in the direction A beyond point C, the telescoping arm begins to extend. Similarly, as the connection moves in the direction B beyond point D, the telescoping arm begins to extend.

The load carried by the trailer 201 may be any suitable load. Examples include but are not limited to containers tanks, milk tanks, containers, loads, or other elongated objects such as logs or power polls. The towing vehicle 203 may be a prime mover, tractor, intermediate trailers, or any other suitable vehicle. In one embodiment, the trailer may not have a chassis instead each dolly 210, 220 may have a bolster and/or stanchions to which the load may be secured, with the load acting as the chassis, such as logging trailers. The dollies being pivotable relative to the bolsters.

Additional trailers employing the telescoping stinger may be attached to the rear of trailer 201. The draw bar for the additional trailer may either be attached the chassis 212 or to second dolly 220.

Locking

The second dolly 220 may (depending on the application requirements) have a locked configuration in which the second dolly 220 is non-pivotable (relative to the chassis) and an unlocked configuration in which the second dolly 220 is pivotable (relative to the chassis). In the unlocked configuration pivoting of the first dolly 210 causes the second dolly 220 to pivot.

Improving low speed turning performance generally has a negative impact on high speed dynamic performance. At high speeds, if the second (rear) dolly 220 is not locked and thus pivotable, in a multi axle dolly configuration the rear axles of the dolly may override the steering ability of the first axle of the dolly, causing opposing wheel drag throughout the axles, stalling and dragging tyres sideways resulting in specific scuffing. However, by locking the second dolly during high speeds, safety and high-speed dynamic performance can be maintained.

Rotation of the second dolly 220 may be prevented and the second dolly 220 locked automatically at speed. The locking configuration may be speed controlled, and activated over a certain speed threshold. For example, the locking threshold may be set at 60 km/h such that when the vehicle speed exceeds 60 km/h, rotation of the second dolly 220 relative to the chassis 212 is automatically locked.

Alternatively, the default position may be that second (rear) dolly 220 is locked with the unlocking mechanism actively operating at lower speeds. Any system failure would then result in the steering being locked which would ensure vehicle safety.

Any suitable mechanism may be used to lock the second dolly 220 relative to the chassis 212. Figures 8 and 9 show examples of locking mechanisms including locking pins 806 which pivot between an unlocked position, in which the pins 806 are substantially horizontal, and a locked position, in which the pins 806 are substantially vertical and are locked within recesses 804 of the chassis 102. The stinger 250 may also be locked. Locking would only be activated when the second dolly 220 is coaxially aligned with the chassis 212, eg in the 'straight' position. Locking and unlocking of the pins 806 may be controlled by a controller.

Test Results

Tanker designs (as applied to a dairy tanker), both with and without locking of the second dolly were tested, and the results are presented in Table 1 as follows:

Table 1

In both cases the low speed turning performance is considerably better than the minimum acceptable level. The steering mechanism results in significant gains with a reduction in low speed off-tracking of 0.58m. The high-speed dynamic performance for the trailer 201 of the second embodiment with steering is adversely affected with the rearward amplification exceeding the limit of 2 and the dynamic load transfer ratio exceeding its limit of 0.6. These two quantities are measured during a 1.46m lane change manoeuvre undertaken at 88km/h.

Undertaking the same 1.46m lane change at 60km/h over a shorter distance so that the peak- to-peak lateral acceleration remains the same give the results shown in Table 2. Thus, the towing vehicle 203 and trailers 201 performance is at acceptable levels at 60km/h.

Table 2

Table 3 below shows a performance assessment according to various measures of the towing vehicle 203 and trailer 201 with and without the second (rear) dolly 220 steering locked.

Table 3

The results of Table 3 show that with the second dolly 220 steering locked, the towing vehicle 203 and trailer 201 has satisfactory performance for all of the performance measures analysed. With the second dolly 220 steering unlocked, the towing vehicle 2013 and trailer 201 has enhanced low speed turning performance at the expense of unsatisfactory high speed dynamic performance. With the second dolly 220 steering locked, high speed dynamic performance at 60 km/h was shown to be satisfactory.

While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of the Applicant's general inventive concept.

Claims

CLAIMS:

1. A trailer for hauling a load, the trailer comprising: a first dolly having at least one axle, the first dolly configured to be pivotable relative to the trailer; a drawbar connected to the first dolly to connect to a towing vehicle; a second dolly having at least one axle, the second dolly configured to be pivotable relative to the trailer; and a telescoping stinger connecting the first dolly and the second dolly, configured to cause the second dolly to pivot depending on pivoting of the first dolly.

2. The trailer claimed in claim 1 wherein the trailer has a chassis to which the load is secured, the first dolly pivotably connected to the chassis towards a front end of the chassis and the rear dolly pivotably connected to the chassis towards a rear end of the chassis.

3. The trailer claimed in claim 2 wherein the load or the chassis does not significantly overhang or cantilever over the first or the second dolly.

4. The trailer claimed in claim 2 wherein the first dolly pivots about a point between 10 to 20% of the length of the trailer from the front most portion of the chassis.

5. The trailer claimed in claim 2 wherein the first dolly pivots about a point approximately 15% of the length of the trailer from the front most portion of the chassis.

6. The trailer claimed in claim 2 wherein the second dolly pivots about a point between 20 to 40% of the length of the trailer from the rear most portion of the chassis.

7. The trailer claimed in claim 2 wherein the second dolly pivots about a point approximately 30% of the length of the trailer from the rear most portion of the chassis.

8. The trailer claimed in any one of the preceding claims wherein the second dolly having a locked configuration in which the second dolly is non-pivotable and an unlocked configuration in which the second dolly is pivotable.

9. The trailer claimed in any one of the preceding claims wherein the load is a tank, a milk tank, an elongated object, a container, at least one log, or at least one power pole.

10. The trailer claimed in any one of the preceding claims wherein the first dolly has two axles.

11. The trailer claimed in any one of the preceding claims wherein the second dolly has at least two axles, or at least three axles.

12. The trailer claimed in any one of the preceding claims wherein the towing vehicle is a prime mover, or a tractor.

13. The trailer claimed in any one of the preceding claims wherein the towing vehicle is an intermediate trailer.

14. A trailer for hauling a load, the trailer comprising: a chassis to which the load is secured, the chassis having a front end and a rear end; a front dolly having at least one wheel set, the front dolly having a front end and a rear end coaxial with the chassis front end and rear end; a front bolster mounted over the front dolly and pivotably connected to the chassis towards the front end of the chassis; a drawbar connected to the front end of front dolly, the drawbar connecting the trailer to a towing vehicle; a rear dolly having at least one wheel set, the rear dolly having a front end and a rear end coaxial with the chassis front end and rear end; an articulated and telescoping stinger connecting the rear end of the front dolly and the front end of the rear dolly; and a rear bolster mounted over the rear dolly, the bolster connected to the chassis towards the rear end, the bolster having a locked configuration in which the bolster is fixedly connected to the chassis to move in unison therewith and an unlocked configuration in which the bolster is rotatably connected to the chassis wherein in the unlocked configuration the articulation of the front dolly causes a steering effect on the rear dolly.

15. A trailer for hauling a load, the trailer comprising: a chassis to which the load is secured, the chassis having a front end and a rear end; a front dolly having at least one wheel set, the front dolly having a front end and a rear end coaxial with the chassis front end and rear end, the front dolly pivotably connected to the chassis towards the front end of the chassis; a drawbar connected to the front end of front dolly, the drawbar connecting the trailer to a towing vehicle; a rear dolly having at least one wheel set, the rear dolly having a front end and a rear end coaxial with the chassis front end and rear end, the rear dolly connected to the chassis towards the rear end, the rear dolly having a locked configuration in which the rear dolly is fixedly connected to the chassis to move in unison therewith and an unlocked configuration in which the rear dolly is rotatably connected to the chassis; and an articulated and telescoping stinger connecting the rear end of the front dolly and the front end of the rear dolly, wherein in the unlocked configuration the articulation of the front dolly causes a steering effect on the rear dolly.

16. A tank for transporting liquids comprising: a tank for receiving liquids; and at least one plate in the tank rotatable from a first position in which the tank is a single chamber and a second position that divides the tank into a first sub chamber and a second sub chamber.

17. A trailer for hauling a load, the trailer comprising: a first dolly having at least one axle; a drawbar connected to the first dolly to connect to a towing vehicle; a second dolly having at least one axle, the second dolly having a locked configuration in which the second dolly is non-pivotable and an unlocked configuration in which the second dolly is pivotable; and a telescoping stinger connecting the first dolly and the second dolly, wherein in the unlocked configuration pivoting of the first dolly causes the second dolly to pivot.