GB2488447A

GB2488447A - A step-frame semi-trailer having a second loading platform

Info

Publication number: GB2488447A
Application number: GB1204412.9A
Authority: GB
Inventors: Alan Lindfield
Original assignee: ALAN LINDFIELD Ltd
Current assignee: ALAN LINDFIELD Ltd
Priority date: 2012-03-12
Filing date: 2012-03-12
Publication date: 2012-08-29
Anticipated expiration: 2032-03-12
Also published as: GB201204412D0; GB2488447B

Abstract

A step frame semi-trailer 1 having a first loading deck extending between a rear and a front of the trailer, the first loading deck 2 comprising a lower step 4 extending within the trailer from the rear and an upper step 3 extending within the trailer from the front. A roof extending between the rear and the front of the trailer 1. A second deck 6 extending within the trailer from the rear, the second loading deck positioned between the lower step 4 of the first loading deck 2 and the roof. Optionally the roof has a downward sloping front portion 5 and a lift 7 is present positioned to receive, in a first configuration, a load 23 from the second loading deck 6 and being arranged to lower the load to the upper step 3 of the first loading deck 2. Alternatively a refrigeration unit (20, Figure 7a) is positioned under the upper step 3 of the first loading deck 2.

Description

Trailer The invention relates to a double deck semi trailer for transporting goods, that is, a trailer designed to be supported by a towing unit such as a tractor unit at one end and having two loading decks.

Articulated lorries, comprising a trailer linked to a tractor unit, are subject to various legal restrictions such as to their height and length. One of the goals in trailer design is to maximise the useable load space available whilst keeping within the relevant legal requirements for lorry size.

One conventional type of semi trailer, often known as a step frame trailer, has a stepped floor design wherein the trailer floor is partly at a relatively higher level to accommodate an axle of a towing unit below the trailer and partly at one or more relatively lower levels in the part of the trailer beyond the towing unit in order to increase load space in this part of the trailer.

In addition to having a stepped frame, useable load space (payload space) can be increased by increasing the number of loading decks. A double deck trailer has a loading deck on the floor of the trailer and another loading deck spaced apart from the first deck and extending at least part way along the length of the trailer.

As well as considering load space in trailer design, in recent years consideration has also been given to minimising fuel consumption of lorries, due to the rising cost of fuel and need to cut emissions.

Traditionally, trailers were cuboid, or in the case of a step frame trailer, a stepped box shape, with poor aerodynamic properties. The height between the road surface and the bottom of a tractor unit of a lorry (where the axles, air tanks, oil sump and the bottom of the fuel tanks are) may be as little as 250mm and the vehicle combination may behave as a solid mass with a void left in the air in the wake of the trailer.

As environmental considerations and fuel costs have become important, various adjustments to the shape of trailers have been considered in an attempt to improve their aerodynamic properties and decrease lorry fuel consumption. The idea of aerodynamic improvement is to channel the air over the top of, and around the sides of a lorry, into the void behind the rear of the trailer, to lessen air resistance in front of the vehicle and then lower fuel consumption.

However, aerodynamic improvement can be restricted by a number of factors such as payload space required, lack of external space available for aerodynamic adjustments and stability issues.

A difficulty with adjusting trailer shape to improve aerodynamics is that useable load space may be sacrificed, given the lorry size restrictions that must be adhered to and, for example, the shape and size of loads. Further, loading into the load space that is available may become more difficult. For example, loads tends to be a cuboid and often standardised shape whilst aerodynamic trailer shape adjustments tend to involve removing right angles from the trailer body. This is exacerbated for loads that must be kept in a certain orientation.

One shape adjustment which improves aerodynamics but which introduces these problems is incorporating a gradual downwards sloping curve towards the front of the roof instead of the entire roof being substantially flat. That is, the end of the roof positioned dosest to the cab of a tractor unit to which the trailer is coupled as part of an articulated vehicle is sloped, so that the trailer height at the front of the trailer where the roof is sloped is less than the height of the remainder of the trailer. The angle between the roof and trailer front face is obtuse and the area of trailer end face perpendicular to the direction of motion of the trailer as part of a moving lorry is reduced. When in motion, air is diverted around the trailer in a manner which reduces drag on the trailer. However this cutting off of the corner of the trailer reduces the internal trailer volume and may reduce the useable volume even further as, for example, standard loads may not be able to be loaded into the space below the curve of the roof, particularly for a rear loading trailer. This means that an upper deck of a double deck trailer may have to be shortened and the benefits of having two loading decks may therefore be reduced.

Attempts have been made to maximise payload while keeping improved aerodynamics by having a moveable upper deck (a lifting deck'). However, this is costly and complex and trailers with such a deck arrangement are problematic to unload, particularly in confined spaces.

Turning now to refrigerated lorries in particular, these have even more problems with fuel consumption, both due to the direct fuel consumption of the refrigeration unit and also because the presence of the refrigeration unit on the trailer affects the aerodynamic properties of a lorry and limits the aerodynamic improvements that can be made.

Refrigerated lorries are also noisy and therefore are limited as to the times of day they can deliver in urban areas.

The invention is set out in the claims.

The claimed invention provides a step frame semi trailer which may maxim ise useable load space within an aerodynamic trailer shape, by means of internal trailer components which may be simple to construct and operate. The provision of a lift positioned to receive, in a first configuration, a load from the second loading deck and being arranged to lower a load to the upper step of the first loading deck may simply and easily, without complex equipment, enable goods to be loaded even into the part of the trailer having a downwards sloping roof.

Such a trailer may have a greater capacity compared to a conventional trailer and as a result, fewer trailers may be needed in a fleet to meet a retailer's logistics requirements for getting stock to stores for example. Further, as a smaller trailer size may be used to transport a given payload, deliveries may be made to harder to access sites which conventional larger sized lorries cannot get to. For example, a supermarket, instead of having large lorries for out of town stores and small lorries for town centre stores may instead have one fleet which can service both types of store. Additionally this may mean that fewer delivery trips are needed to the town centre stores. All of this may result in huge environmental benefits and a reduction in congestion on roads.

The lift may be cheap, and simple to install and may mean that it is not necessary to have a more complex, expensive, moveable second deck. The lift may be a conventional tail lift adapted for use inside the trailer. The lift may be compact and may support a load while the trailer is in motion.

The position of the lift within the trailer, the configuration in which a load is received from the second deck and the configuration when a load has been lowered on to the upper step of the first deck (the swan' deck) may maximise the load capacity of the trailer and maximise support and stability of the lift gained from the trailer. By lowering the load in the swan deck, the centre of gravity of the swan deck part of the load may be lowered thus also improving the stability of the trailer and the trailer aerodynamics.

The claimed trailer with internal lift may improve flexibility of deliveries and unloading because it is only necessary to unload the second deck before unloading the upper step of the first deck, in contrast with conventional double deck trailers having a moving second deck where it is necessary to unload both the lower step of the first deck and the second deck before unloading the upper step of the first deck. Further, it is possible to reload items such as empty cages back on to the lower step of the first deck of the trailer before emptying part or all of the rest of the trailer.

The claimed invention further provides a step frame semi trailer having a refrigeration unit attached under the swan deck, which may increase useable load space in a refrigerated trailer compared to a conventional refrigerated trailer having a refrigeration unit attached to the front of the trailer. Additionally, this position of the refrigeration unit allows for the aerodynamics of the trailer and of the trailer and tractor unit combination to be improved as there is no refrigeration unit occupying space at the front end of the trailer.

Conventional refrigerated systems fitted to the front of articulated trailers greatly restrict aerodynamic design because the refrigeration unit takes up a lot of space on the front of the trailer (usually leaving only space for the "nosebox" where the electrical and compressed air connections are situated). This leaves little option for any aerodynamics on the front of the trailer. By placing the refrigeration unit underneath the loading deck in the swan neck, the top of the cab of the tractor unit and front of the trailer can in combination be given a much more aerodynamically favourable shape than is possible with a unit in the way. The positioning of the refrigeration unit may also improve the stability of the trailer and may mean there is less weight on the front axle of the tractor unit.

Conventional refrigerated trailers also have problems with the refrigeration units being damaged, due to their vulnerable position on the front of the trailer. For example, tree branches and other overhanging objects may cause damage. A refrigeration unit positioned under the upper step of the lower deck is much better protected from damage.

Further, this positioning may be an optimum position on a trailer to optimally soundproof the refrigeration unit, so that a lorry with this refrigeration system may be quieter than conventional refrigerated lorries. One or more evaporators may also be present under the upper step without comprising load space. The refrigeration unit and any evaporators under the upper step are also much easier to access and maintain in this position.

Powering the refrigeration using a vehicle engine driven refrigeration (VEDR) system may be more efficient than using a separate secondary engine and also means a refrigerated lorry using VEDR instead of secondary engine driven refrigeration (SEDR) system may be safer (as no secondary diesel engine fuel tank is required) as well as having better fuel consumption and lower emissions. SEDR systems may use three times the fuel of an efficient VEDR system. Further, the VEDR refrigeration unit may be lighter and having this under the upper step of the first loading deck, without a separate secondary engine, may save space and weight and enable a better payload to be obtained.

Examples according to the present invention are described below, with reference to the accompanying drawings in which: Figure 1 is a diagram of an example trailer without a refrigeration Unit; Figure 2 is a diagram of an example articulated lorry comprising a trailer as shown in figure 1; Figure 3 shows an example lift; Figure 4 is a diagram of an example trailer with a refrigeration unit; Figure 5 is a diagram of an example articulated lorry comprising a trailer as shown in figure 4; Figures 6a to 6c are simplified schematic diagrams of a lorry as shown in figure 2 in three stages of loading during an example loading sequence; and Figures 7a to 7c are simplified schematic diagrams of a lorry as shown in figure 5 in three stages of loading during an example loading sequence.

Figure 1 shows an example step frame semi trailer 1. The trailer I has a floor 2 which is a first loading deck and which has an upper step 3 and a lower step 4. The part of the trailer 1 containing the upper step 3 may be known as a swan neck and the upper step 3 of the first loading deck may be known as a swan deck 3. The lower step 4 may be known as the bottom deck 4. The trailer I has a downwards sloping portion of roof 5 at the front above the swan deck 3. The trailer I also has a second loading deck 6 above the bottom deck 4.

The second deck 6 may be known as the top deck 6. A lift 7 is positioned on the swan deck 3 adjacent to the end of the top deck 6. In the example shown in figure 1, the top deck 6 extends partly over the swan deck 3. The trailer I has rear axles 8 but no front axle.

Figure 2 shows the trailer I of the type depicted in figure 1 coupled to a tractor unit 9 with a coupling 10 to form an articulated lorry. The weight of the trailer I is partially supported by the tractor unit 9 with the floor 2 of the trailer being stepped to accommodate an axle 11 of the tractor unit. The tractor unit 9 has an aerodynamic shaping 12 on the top of the driver's cab 13.

The lift 7 may be hydraulic, pneumatic or mechanical. Figure 3 shows details of an example lift fitted internally. The lift 7 has a platform 14 which can support a load. In this example the lift 7 further comprises a ramp 15 to facilitate wheeling a load on and off the lift floor 14. In this example, the lift 7 further has guard rails 16 and straps 17 to contain a load and moveable stops 18 to secure wheels of a load cage in transit. Any guard rails 16, stops 18 and straps 17 may be designed to fold away. The lift 7 may be a conventional tail lift, as known by the skilled person, adapted to be fixed internally. For example, lift columns 19 may be adapted by moving the columns so as to be suitable for fitting inside rather than outside the trailer. The lift 7 may be a standard size such as having a lifting capacity of 1500 kg or a bespoke size, for example having a lifting capacity anywhere from 1000 to 2000 kg.

A refrigeration unit 20 may be positioned under the swan deck 3 as shown in figure 4. As can be seen in figure 4, the refrigeration unit 20 may be positioned on the floor 2 of the swan neck, in a space which may be known as the refrigeration box', with the swan deck 3, that is, the actual loading deck 3 of the swan neck, being a second floor raised above the refrigeration unit 20 and floor 2. Figure 4 also shows vents 21 and evaporators 22 which may be further parts of a refrigerated trailer 1. One or more evaporators 22 may be positioned inside the refrigeration box to chill, freeze or heat the bottom deck 2 for example, without compromising the load space. Although the refrigeration unit 20 is shown in conjunction with an internal lift 7, the lift 7 does not have to be present. The refrigeration unit 20 may be soundproofed (not shown). Figure 5 shows such a trailer I as part of an articulated lorry, in the same example manner as shown in figure 2 for an unrefrigerated trailer 1.

The refrigeration system may be vehicle engine driven refrigeration (VEOR). This means that the refrigeration system can be powered by the engine of the tractor unit 9 or mains power as opposed to secondary engine driven refrigeration (SEOR) which is refrigeration which can be powered by its own engine or mains power. The Coolstart System by Govers e.t.b.v. (www.goverset.nl) may be used to provide the VEOR. This makes it possible to power the refrigeration from the lorry engine without needing to have the engine continuously running when the lorry is stationary, as the Coolstart System starts the lorry engine only when the trailer temperature needs altering (for example when it rises above a certain temperature in a cooled trailer).

A refrigerated lorry with the soundproofed refrigeration unit 20 in place under the swan deck 3 and the refrigeration unit 20 powered as described above may arrive on site at a reduced noise level compared to standard refrigerated lorries. Then the vehicle engine can be turned off and the refrigeration unit plugged into the delivery points electrical supply.

Figures 6a to 6c show an example of how an unrefrigerated trailer I may be loaded and figures 7a to 7c the refrigerated trailer I. The trailer I is loaded from the rear 25. On loading, as shown in figures 6a and 7a, an example loading sequence starts by a load 23 being pushed from the rear 25 of the trailer I on to the lift 7. Figures 6 and 7 show loading from the rear of the trailer I using an external lift 24 in a known manner. The internal lift 7 is positioned such that the load 23 can be pushed along the top deck 6 on to the lift platform 14 which is adjacent to the end of the top deck 6. Figures 6b and 7b show the partly loaded trailer I with this first load 23 lowered on to the swan deck 3 and the lift 7 part of the way through lowering a second load 23 from the top deck 6 to swan deck 3.

When the swan deck 3 is full, including having load on the lift 7, the bottom deck 4 and top deck 6 can be loaded, in either order. Alternatively, the bottom deck 4 can be loaded before the swan deck 3. Figures 6c and 7c show an example fully loaded trailer 1.

Unloading can occur in the reverse sequence, with either the bottom deck 4 being unloaded first, followed by the top deck 6 then swan deck 3, or the top deck 6 unloaded first followed by the swan deck 3 and bottom deck 4 in either order.

An example of the possible increase in payload is an II m long trailer according to an example of the invention accommodating 59 cages of dimensions 1860mm high by 760 mm wide by 850 mm deep, compared to a 13.6m long conventional semi trailer accommodating 48 such cages. Examples of smaller vehicles instead of which an 11 m long trailer according to an example of the invention accommodating 59 standard cages may be used are urban trailers carrying up to 39 cages and rigid vehicles carrying up to 27 cages. Similarly, a trailer according to an example of the invention may accommodate trolleys of the type used to transport plants compared to 24 or 26 of such trolleys accommodated by conventional rigid vehicles used to access plant delivery points.

Having a length of 11 m may enable the trailer to turn corners which conventional 13Mm trailers cannot turn. This may increase the number of delivery points that can be accessed without resorting to using a smaller type of vehicle such as having an urban trailer or a rigid vehicle. Such an 11 m trailer may also have a reduced height compared to a standard double deck. trailer, which may enable the trailer to fit under bridges and access areas under which such conventional trailers cannot pass.

A further example trailer may have a length of 15.8m and may increase capacity by having a longer length but reduced height as compared to conventional maximum size, high slung, double deck trailers.

Cages and trolleys are given as examples of loads 23 above. The cage may be a roll cage, such as those used for deliveries to supermarkets, loaded on to the trailer by being manually pushed into place on a deck 2, 6 from the opened rear 25 of the trailer 1. Roll cages may also be known as roll containers and roll pallets. Further example loads are palletised loads.

The trailer I may be rear loading or side loading, otherwise known as a curtainsider, or a combination of the two. For example, the trailer I may have a top deck 6 and swan deck 3 that are curtainsided and a bottom deck 4 that is fully enclosed. To facilitate different types of goods being loaded on to a curtainsider, the lift 7 may be arranged ta be vertically stowed. The top deck 6 may be a fixed deck or a lifting deck -although the lift 7 may eliminate the need for a lifting deck, it would also be possible for the trailer I to contain both the lift 7 and a lifting deck. Although in the attached figures shown the top deck 6 partly overlapping the swan deck 3 the top deck 6 may end where the bottom deck 4 ends.

The roof 5 may have any suitable geometry incorporating a downwards sloping front portion, as known by the skilled person. The trailer 1 shown in the figures has the entire roof 5 shaped to optimise the aerodynamic properties of the trailer 1. It would be possible however, for example, to have a roof predominantly parallel to the loading decks with just a downwards slope at the front part of the roof 5. The slope may or may not have a constant gradient, being curved for example.

The trailer I may be refrigerated or unrefrigerated or a combination of the two. For example, it may have a non refrigerated top deck 6 and a refrigerated bottom deck 4.

The articulated lorry may comprise any known tractor unit and any known coupling linking the tractor unit to the trailer. For example the coupling may be a fifth wheel coupling as known to the skilled person. Alternative towing units may be coupled to the trailer such as the tail of another trailer.

The terms lorry and truck are interchangeable. An articulated lorry may also be known as, for example, an artic', an articulated lorry, semi-trailer truck, trailer-truck, semi-truck. Semi trailers may also be known by terms such as semitrailers, semi-trailers, swan neck trailers.

A tractor unit may also be known as, for example, a tractor, a road tractor, a traction unit, a prime mover. -10-

Claims

CLAIMS1. A step frame semi trailer comprising: a first loading deck extending between a rear and a front of the trailer, the first loading deck comprising a lower step extending within the trailer from the rear and an upper step extending within the trailer from the front; a roof extending between the rear and the front of the trailer, the roof having a downwards sloping front portion; a second loading deck extending within the trailer from the rear, the second loading deck positioned between the lower step of the first loading deck and the roof; and a lift positioned to receive, in a first configuration, a load from the second loading deck and being arranged to lower the load to the upper step of the first loading deck.
2. A trailer according to claim 1, wherein the lift has a platform which is flush with the second loading deck in the first configuration of the lift.
3. A trailer according to claim I or claim 2, the trailer having a loaded configuration wherein the lift is arranged to support a load.
4. A trailer according to claim 3, wherein the loaded configuration of the trailer corresponds to a second configuration of the lift wherein the lift is in a lowest position.
5. A trailer according to any preceding claim, wherein the lift is one of a hydraulic, pneumatic or mechanical lift.
6. A trailer according to any preceding claim, wherein the second loading deck is fixed in position relative to the first loading deck.
7. A trailer according to any preceding claim, wherein the trailer is a rear loadable trailer.
8. A trailer according to any preceding claim, wherein the trailer is a rear loading trailer.
9. A trailer according to any preceding claim, further comprising a refrigeration unit positioned under the upper step of the first loading deck.
10. A step frame semi trailer comprising: a first loading deck extending between a rear and a front of the trailer, the first S loading deck comprising a tower step extending within the trailer from the rear and an upper step extending within the trailer from the front; a roof extending between the rear and the front of the trailer; a second loading deck extending within the trailer from the rear, the second loading deck positioned between the lower step of the first loading deck and the roof; and a refrigeration unit positioned under the upper step of the first loading deck.
11. A trailer according to claim 9 or claim 10, wherein the refrigeration unit is positioned between the upper step and a floor of the trailer.
12. A trailer according to claim 11, further comprising one or more evaporators between the upper step and the floor of the trailer.
13. A trailer according to any of claims 9 to 12, wherein the refrigeration unit is soundproofed.14. A trailer according to any of claims 9 to 13, wherein the refrigeration unit is powered by a vehicle engine driven refrigeration (VEDR) system.
14. An articulated vehicle comprising: a towing unit; a trailer according to any preceding claim; and a coupling arranged to couple the towing unit to the trailer.
15. A vehicle according to claim 14, wherein the towing unit is a tractor unit.
16. A vehicle according to claim 14 or claim 15, wherein the vehicle is a lorry.AMENDED CLAIMS HAVE BEEN FILED AS FOLLOWSCLAIMS1. A step frame semi trailer comprising: a first loading deck extending between a rear and a front of the trailer, the first loading deck comprising a lower step extending within the trailer from the rear and an upper step extending within the trailer from the front; a roof extending between the rear and the front of the trailer, the roof having a downwards sloping front portion; a second loading deck extending within the trailer from the rear, the second loading deck positioned between the lower step of the first loading deck and the roof; and a lift positioned to receive, in a first configuration, a load from the second loading deck and being arranged to lower the load to the upper step of the first loading deck.2. A trailer according to claim 1, wherein the lift has a platform which is flush with the second loading deck in the first configuration of the lift.3. A trailer according to claim I or claim 2, the trailer having a loaded configuration wherein the lift is arranged to support a load.4. A trailer according to claim 3, wherein the loaded configuration of the trailer corresponds to a second configuration of the lift wherein the lift is in a lowest position.5. A trailer according to any preceding claim, wherein the lift is one of a hydraulic, pneumatic or mechanical lift.6. A trailer according to any preceding claim, wherein the second loading deck is fixed in position relative to the first loading deck.7. A trailer according to any preceding claim, wherein the trailer is a rear loadable trailer.8. A trailer according to any preceding claim, wherein the trailer is a rear loading trailer.9. A trailer according to any preceding claim, further comprising a refrigeration unit positioned under the upper step of the first loading deck.10. A trailer according to claim 9, wherein the refrigeration unit is positioned between the upper step and a floor of the trailer.11. A trailer accordiflg to claim 10, further comprising one or more evaporators between the upper step and the floor of the trailer.12. A trailer according to any of claims 9 to 11, wherein the refrigeration unit is soundproofed.13. A trailer according to any of claims 9 to 12, wherein the refrigeration unit is powered bya vehicle engine driven refrigeration (VEDR) system.* 14. An articulated vehicle comprising: a towing unit; * a trailer according to any preceding claim; and * a coupling arranged to couple the towing unit to the trailer.15. Avehicle according to claim 14, wherein the towing unit is a tractor unit.16. A vehicle according to claim 14 or claim 15, wherein the vehicle is a lorry. S. * * S S * S. * * * S. *5. -S * I. ** * * . OS * *S ** *