GB2413995A

GB2413995A - Split-chassis load carrying vehicle

Info

Publication number: GB2413995A
Application number: GB0410902A
Authority: GB
Inventors: Paul Anthony Raven; Kevin William Raven
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-14
Filing date: 2004-05-14
Publication date: 2005-11-16
Anticipated expiration: 2024-05-14
Also published as: GB0410902D0; GB2413995B

Abstract

A split-chassis load carrying vehicle, for example a non-articulated split-chassis truck or an articulated flatbed or skeletal split-chassis trailer, having forward and rearward chassis sections that may be brought together and joined, or separated. The vehicle (1) comprises a forwards chassis section (4), a rearwards chassis section (2), said chassis sections extending along a longitudinal axis, and a bogie section (6) having road-running gear including a set of road-going wheels (11). The bogie section (6) is movable relative to the chassis sections (2,4) and securable to these sections by means of an axial securing mechanism (50,52;36,53). The forwards chassis section (4) and the rearwards chassis section (2) are releaseably joined to each other to form the vehicle (1) by means of an axial engagement mechanism (26,32,42) which when disengaged allows said chassis sections (2,4) to be separated. The arrangement is such that the securing mechanism(50,52;36,53) allows the bogie section (6) to be secured to the forwards chassis section (4) at at least two axial locations along the length of the forwards chassis section (4).

Description

- 1 241 3995 Split-chasi. Load Carrying Vehicle

BACKGROUND

a. Field of the Invention

The present invention relates to a vehicle for carrying goods, commodities, materials, containers or other such loads that may need to be delivered to or collected from different locations, or be offloaded from or loaded on the vehicle at different times. In particular the invention relates to a split-chassis load carrying vehicle, for example a nonarticulated split-chassis truck or an articulated flatbed or skeletal split-chassis trailer, having forward and rearward chassis sections that may be brought together and joined, or separated.

b. Related Art When transporting goods, it is often not possible or desirable to load a truck or a trailer with goods going to one particular destination or being unloaded at one time. As a result, two such delivery vehicles may need to be used to complete the delivery, or one vehicle may have to be used with the limitation that the vehicle may be delayed by loading or unloading at an intermediate destination.

It is common in the field of containerized transport of goods to use a flatbed or a skeletal trailer having a rear sliding bogie section that allows the trailer to be extendible between two lengths, for example 6.lm (20 feet) and 12.2 m (40 feet). In one mode of usage, the length of the trailer is locked at either of these lengths for mounting of containers 2 - with these lengths. A 13.6 m (45 feet) container may also be carried on a 12.2 m trailer. Alternatively, the length of the trailer may be locked in the extended position to permit greater axle loading, according to the law. For example, a 6.1 m (20 feet) container above a certain weight may be required by law to be carried by a 12.2 m trailer in order to spread the axle loading.

The extension may be accomplished by having the set of wheels on a bogie which is itself fixed to a slider mechanism for slideably moving the bogie relative to the chassis section.

Examples such extendible trailers are disclosed in patent documents GB 2 298 399 A and WO 03/011636 Al.

Extendible trailers allow a driver to load various types of ISO container configurations, namely 1 x 12.2 m (40 feet) container standard or "High Cube" height, 1 x 13.6 m (45 feet) container standard or "High Cube" height, 1 x 9.1 m (30 feet) container, 1 x 6.1 m (20 feet) "Heavy" (at least 24 tonne) container standard or "High Cube" height placed in the centre of the trailer for axle loading laws and 2 x 6.1 m (20 feet) containers standard or "High Cube" height. The containers are collected from the docks and given to the operators for delivery. When the trailer is extended, it is able to carry all of the above container sizes, however the "Heavy" 6.1 m container must be centrally mounted in order to comply with axle loading laws. In the extended position, the rear "Heavy" 6.1 m container doors cannot be accessed for unloading without retracting the trailer into the closed position. To close the trailer the driver can operate the locking mechanism either from his cab or at controls located outside on the trailer to unlock the section, and then with the rear wheels locked, reverse the cab into its retracted position, closing the trailer fully allowing the container doors to become flush with the rear of the trailer for off- loading.

Due to nature of the work the haulier does not know in advance which type of container he may have to carry for the next delivery. Although extendible trailers provide numerous advantages over non-extendible trailers, they do not provide a complete solution to the problems of delays from loading or unloading at intermediate delivery or collection locations.

It has therefore been proposed to use a split-chassis trailer, such as that disclosed in patent document EP 0 649 772 Al. This discloses a trailer having a forwards chassis section and a rearwards chassis section each of which is capable of carrying a 6.1 m container and which may be joined together or separated as required. When joined together the sections may carry one 12.2 m container. Each section has a full set of wheels so that the rearward section may be dropped off or collected from a location, thus minimizing delays from loading or unloading at intermediate locations. When the rearward section is to be separated from the forwards section, a forwards set of wheels on air suspension is dropped to support the forwards section. When the rearward section is joined to the forward section, the forwards set of wheels is raised to reduce drag and Lyre wear.

A number of limitations have been noted with this type of split-chassis trailer. First, there is the need for additional road-running gear and an associated set of road 4 - going wheels in the forwards chassis section. Although this adds to cost, the most significant limitation is the additional weight which limits the load that such a trailer may legally carry on the public highway in the United Kingdom and in continental Europe.

Furthermore, this type of split-chassis trailer is not able to carry all container configurations, loaded and unloaded, legally in compliance with both UK and continental European axle and height laws. The UK and continental European road haulage industry standard generally insists, due to cost and breakdown availability, that chassis are operated on super single 385 x 65 x R22.5 tyre size, rather than more expensive lower diameter Lyres. This has split the UK and Continental European trailer manufactures into producing various types of the skeletal sliding bogie trailers and split-chassis trailers. In continental Europe there is a bridge height law setting a maximum clearance height of 4 m. As a result, the Continental European market requires what is known as a "Goose Neck" front to the trailer allowing a 13.6 m or 12.2 m (45 feet or 40 feet) "High Cube" container to sit lower on the chassis beams, thus reducing the container height by around 120 mm to 160 mm in order to get the overall height of the loaded container underneath the 4 m bridge clearance height. To comply with current Continental European laws and regulations, Continental European manufactures build sliding skeletal trailers with axle weight configurations that would not meet current British axle weight laws. The UK does not allow such low bridge heights on main routes, so it is not as beneficial to have a "Goose Neck" front to the trailer.

Consequently, trailers for use in the UK are much cheaper to produce, and a "High Cube" container can be carried sitting - 5 - on top of the trailer chassis as opposed to within the neck of a trailer chassis.

Because of the excess weight from the additional set of road going wheels, which for a commercially viable trailer need to be of the standard size, the trailer disclosed in EP 0 649 772 Al could not in practice carry a "High Cube" container on continental European roads or certain types of "Heavy" container on UK roads.

Furthermore, such a trailer could not legally carry on UK roads a 6.1 m "Heavy" container using only the forwards chassis section. Axle loading regulations set by the Vehicle and Operator Services Agency (VOSA) of the UK Government Department of Transport require that a standard short trailer having a separation of 4.57 m between the front connection king pin and the rear axle is limited to 25,135 kg Gross Train Weight (GTW) i.e. the total weight of the loaded vehicle, including for trailers also the weight of the tractor unit. Such a short trailer may therefore not carry some 6.1 m "Heavy" containers, which may require a GTW of up to about 32,725 kg.

There is therefore a need for a UK/European split-chassis load carrying vehicle, and particularly a split-chassis trailer, that provides a greater legal load carrying capacity and ideally allows all container configurations, including "High Cube" containers. Such a trailer should ideally comply with all current axle weight laws including relevant bridge height legislation on the super single 385 x 65 x R22.5 Lyre size or equivalent, which is the industry standard low cost

tyre specification. - 6 -

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a more convenient and useful split-chassis load carrying vehicle.

According to the invention, there is provided a split-chassis load carrying vehicle, comprising a forwards chassis section, a rearwards chassis section, said chassis sections extending along a longitudinal axis of the vehicle, and a bogie section having road-running gear including a set of road-going wheels, wherein: - the bogie section is relatively movable with respect to the forwards and rearwards chassis sections between a forwards position beneath the forwards chassis section and a rearwards location beneath the rearwards chassis section at which positions the bogie section may be secured to either the forwards chassis section or the rearwards chassis section by means of a securing mechanism; - the forwards chassis section and the rearwards chassis section are releaseably joined to each other to form the vehicle by means of an engagement mechanism which when disengaged allows said chassis sections to be separated; and - the arrangement is such that the securing mechanism allows the bogie section to be secured to the forwards chassis section at at least two axial locations along the length of the forwards chassis section. - 7

When the forwards chassis section of the vehicle is to be used on its own to carry a short, "Heavy" load, then the bogie section may be moved to a rearwards location in order to increase the distance between the rearmost bogie axle and a forwards axle of the vehicle, thereby increasing the permissible Gross Train Weight (GTW) of the vehicle according to the law.

The bogie section may have one or more axles for road-going wheels. The bogie section may also be securable to the forwards chassis section at one axial location in which a rearmost axle is forwards of a rearmost edge of the forwards chassis section, and is securable to the forwards chassis section at another axial location in which the rearmost axle is rearwards of the rearmost edge of the forwards chassis section.

The bogie section when secured to the forwards chassis section is preferably axially constrained between a forwardmost axial location and a rearwardmost axial location.

Thus, the bogie section may not accidentally become decoupled from the forwards chassis section.

The securing mechanism may include a movable member which (when the forwards chassis section is secured to the bogie section) is fixed at one axial location on one of said sections and is fixed at one of a plurality of axial locations on the other of said sections. The movable member then moves between said plurality of axial locations when the bogie section is moved between axial locations along the length of the forwards chassis section. The movable member - 8 may be an axially movable member, i.e. moving along a longitudinal axis of the vehicle.

The movable member is preferably fixed at one axial location on the bogie section and moves between a pair of axial locations on the forwards chassis section.

Preferably, both the forwards chassis section and the bogie section have a pair of longitudinally extending frame members that extend along either side of a longitudinal axis of the vehicle, and the movable member extends vertically between both pairs of longitudinal frame members.

The movable member preferably moves along a longitudinal axis of the vehicle, when the bogie section is moved between axial locations along the length of the forwards chassis section.

The movable member may include at least one pin which engages with at least one clasp (which are most preferably a pair of non-movable, or fixed, clasps) at said axial locations at which the bogie section is secured with the forwards chassis section.

In a preferred embodiment of the invention, the pin is a double pin that extends upwards between a pair of inwardly facing clasps in the forwards chassis section and downwards to engage with a clasp in the bogie section when the bogie section is secured to the forwards chassis section.

The engagement mechanism may comprise an axially extending projection on one chassis section that engages with a complementary feature on the other chassis section as the two 9 - sections are brought together to be joined, a portion of the securing mechanism in the bogie section moving beneath the axially extending projection as the chassis sections are to be joined or separated.

In preferred embodiments of the invention, the projection is a forwards projection on the rearwards chassis section, and the complementary feature is a matching recess on the forwards chassis section. The recess may be a sleeve with continuous walls, but preferably has discontinuous engagement surfaces so as to help save weight.

Also in preferred embodiments, the engagement mechanism extends in a volume beneath a support surface such as container mounts or a loadbearing floor of the vehicle for carrying a load.

The engagement mechanism may comprise a locking mechanism, such as a pin on one section that engages with a clasp on the other section when said sections are locked together.

The securing mechanism and the engagement mechanism may each comprise at least one pin on one of the sections and at least corresponding one clasp on the other of the sections for receiving the pin. The at least one clasp is then provided on the bogie section and/or the forwards chassis section and the rearwards chassis section not having any such clasp(s) when said chassis sections are separated and with the bogie section having been moved beneath the forwards chassis section.

In a first embodiment of the invention, the vehicle is a - 10 flatbed trailer.

In a second embodiment of the invention, the vehicle is a skeletal trailer for carrying containerized loads. In this case, the support members for supporting a containerized load may be provided on substantially parallel elongate frame members of the forwards chassis section and/or the rearwards chassis section.

In general the vehicle may have at least one drop-down support for supporting the rearward chassis section when the bogie section is moved to the forwards chassis section and when the rearwards section is separated from the forwards chassis section.

The forwards chassis section may be formed utilising a forwards pair of substantially parallel elongate frame members that extend on opposite sides of the longitudinal axis of the vehicle.

Similarly, the rearwards chassis section may be formed utilising a rearwards pair of substantially parallel elongate frame members that extend on opposite sides of the longitudinal axis of the vehicle.

These forwards and rearwards pairs of longitudinal frame members are then longitudinally aligned when the forwards chassis section is joined to the rearwards chassis section.

This permits the bogie section to slide on said aligned longitudinal frame members as the bogie section moves between the forwards chassis section and rearwards chassis section. - 11

In preferred embodiments of the invention, the engagement mechanism extends downwardly beneath a load carrying level of the vehicle into a space between the aligned longitudinal frame members. The bogie section then has one or more transverse frame members that extend between the longitudinal frame members and which are configured with a lowered profile in a central portion of the transverse member(s) as compared with laterally adjacent portions so as to allow passage of the bogie section beneath the downwardly extending engagement mechanism.

The securing mechanism may comprise a clasp mechanism in the bogie section that engages with a downwardly extending pin in the forwards chassis section and/or the rearwards chassis section as the bogie section is secured to the respective chassis section.

In preferred embodiments of the invention, the securing mechanism comprises a pair of clasps on the bogie section and a pair of downwardly extending pins, one of said pins being on the forwards chassis section and the other of said pins being on the rearwards chassis section. The arrangement is such that as the bogie section moves between said chassis sections one of the pins is released by and moves away from one of said clasps and the other of said pins moves towards and enters the other of said clasps. The pair of clasps may each have an entrance for receiving said respective pin, said entrances facing in opposite longitudinal directions.

Also in preferred embodiments of the invention, the securing mechanism comprises a pair of clasps on the forwards chassis section, and the downwardly extending pin on the chassis - 12 section is connected to an upwardly extending pin that moves between said pair of clasps on the forwards chassis section.

Each of said connected pins may have an axis, with these axes being aligned with one another The pair of clasps on the forwards chassis section may each have an entrance for receiving the upwardly extending pin, the entrances to the clasps then facing in towards each other.

In one aspect of the invention, the vehicle comprises an automatic control system for controlling the separation and joining of the forwards and rearwards chassis section which, when the rearwards chassis section is to be separated from the forwards chassis section, the control system being arranged to: a) apply a brake to the wheels of the bogie section; b) release the securing mechanism to disengage the bogie section from the rearwards chassis section; c) permit the vehicle to move in a reverse direction with the bogie section remaining stationary until the securing mechanism engages with the forwards chassis section; and d) release the engagement mechanism after the bogie section has been supported by drop down legs on the bogie section.

18. A vehicle as claimed in Claim 17, the vehicle comprising an automatic control system for controlling the securing of the bogie section to the forwards chassis section at said at - 13 least two axial locations along the length of the forwards chassis section, in which following separation of said chassis section said control system is arranged to: f) apply a brake to the wheels of the bogie section; g) release the securing mechanism to disengage the bogie section from the forwards chassis section at one of said axial locations; and h) permit the vehicle to move in a either a reverse direction or a forwards direction with the bogie section remaining stationary until the securing mechanism engages with the forwards chassis section at another of said axial locations.

The brakes may then be released, also under control of the automatic control system.

Also according to the invention, there is provided a motive vehicle for carrying a load, comprising a tractor unit in combination with a splitchassis load carrying vehicle, said split-chassis load carrying vehicle being according to the invention.

The invention further provides a forwards chassis section for connection to a rearwards chassis section to form a split- chassis vehicle, said forwards chassis section comprising: - a bogie section having road-running gear including a set of road-going wheels, the bogie section being engaged to the forwards chassis section by means of a securing mechanism; - 14 - a portion of an engaging mechanism by which the forwards chassis section may be releaseably engaged with a rearwards chassis section to form the split-chassis vehicle; wherein - the bogie section is movable in a longitudinal direction with respect to the forwards chassis section towards a rearwards chassis section when the securing mechanism is released; and - the securing mechanism allows the bogie section to be secured to the forwards chassis section at at least two axial locations along the length of the forwards chassis section The invention additionally provides a method of forming a split-chassis load carrying vehicle, said vehicle comprising a forwards chassis section, a rearwards chassis section, said chassis sections extending along a longitudinal axis of the vehicle, a bogie section releaseably secured to the forwards chassis section at one of a plurality of axial locations by means of a securing mechanism and having road-running gear including a set of road-going wheels, and an engagement mechanism for releaseably engaging said chassis sections together, the method comprising when the bogie section is not secured to the forwards chassis section at a forwardmost axial location the steps of: i) braking the wheels of the bogie section and releasing the securing mechanism to free the bogie section for relative sliding movement with respect to said forwards chassis section; 15 ii) backing the forwards chassis section in a rearwards direction with the bogie section stationary until the bogie section is secured to the forwards chassis section at a forwardmost axial location; iii) releasing the braking of the wheels of the bogie section; iv) backing the forwards chassis section towards the rearwards chassis section make the engagement mechanism engage said chassis section together and thereby join said chassis sections together; v) braking the wheels of the bogie section and releasing the securing mechanism to free the bogie section for relative sliding movement with respect to said joined chassis sections; and vi) moving said joined chassis sections forwards with the bogie section stationary until the bogie section is secured to the rearwards chassis section by means of the securing mechanism.

The engagement mechanism may, optionally, be an axial engagement mechanism. In the present application, the term "axial engagement mechanism" means an engagement mechanism that lies on or adjacent to the longitudinal axis (or, equivalently, a vertical plane through the longitudinal axis). When there is a pair of longitudinal frame members in - 16 a chassis section, the engagement mechanism lies between this pair of frame members.

Similarly, the securing mechanism may, optionally, be an axial securing mechanism. The term "axial securing mechanism" means a securing mechanism that lies on or adjacent to the longitudinal axis (or, equivalently, a vertical plane through the longitudinal axis). When there is a pair of longitudinal frame members in a chassis section, the securing mechanism lies between this pair of frame members.

Preferably, the axial engagement mechanism is located on or centered about, a longitudinal axial plane that bisects the chassis sections Similarly, the axial securing mechanism is preferably located on or centered about, a longitudinal axial plane that bisects the chassis sections.

The forwards section may have a downwardly extending king pin for engagement with a fifth-wheel coupling mechanism of a tractor unit.

A number of important advantages stem from the combination and arrangement of the axial engagement mechanism between the forwards and rearwards chassis sections and the axial locking mechanism between the bogie section on the one hand and the forwards and rearwards chassis sections on the other hand.

For example, since the centre of mass of the chassis sections will normally lie close to the longitudinal axis of the vehicle, the axial location of the engagement mechanism means that any forces transmitted between the sections when the vehicle is moving on the road will tend to pass through or relatively close by the engagement mechanism, thus helping to - 17 minimise any twisting forces on the engagement mechanism.

Furthermore, when the engagement mechanism is axial, then it is easier for an operator of the trailer to align the portions of the engagement mechanism when joining the chassis sections together. This is because an axial engagement mechanism can be designed to allow for some degree of lateral misalignment and/or skew misalignment between the longitudinal axes of the chassis sections as these are brought together.

In general, it is also better to have such mechanisms provided at an axial location rather than, for example, closer to the sides of the vehicle, such as laterally extending pins between overlapping longitudinal frame members, since an axial location is inherently more sheltered from interference and accidental damage. There is also a safety benefit in that an axial location is removed from personnel who may be beside the trailer when the mechanisms are operated.

An axial location for the engagement mechanism and the securing mechanism also helps to avoid conflict with those parts of the trailer connected to or near the vehicle body or longitudinal frame members, such as drop-down landing gear, any fixed wheels and the wheels of the sliding bogie section.

The securing mechanism may comprise a clasp mechanism in the bogie section that engages with a downwardly extending pin in the forwards chassis section and/or a downwardly extending pin in the rearwards chassis section as the bogie section is secured to the respective section. 18

Preferably, the downwardly extending pins in the rearwards chassis sections are non-moveably affixed to the rearwards section.

The securing mechanism may comprise a pair of clasps on the bogie section and a pair of downwardly extending pins, one of said pins being on the forwards chassis section and the other of said pins being on the rearwards chassis section, the arrangement being such that as the bogie section moves between said chassis sections one of the pins is released by and moves away from one of said clasps and the other of said pins moves towards and enters the other of said clasps.

The pair of clasps may then each have an entrance for receiving a respective pin, the entrances being arranged to face in opposite longitudinal directions, for example along the longitudinal axis of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view from above of a rearwards chassis section of a split-chassis load carrying vehicle according to a first preferred embodiment of the invention, having a flatbed floor for supporting a load, a fixed bogie with a set of wheels, and front and rear pairs of drop-down supports; 19 Figure 2 is a side view of the rearwards chassis section of Figure 1; Figure 3 is a perspective view from above of the rearwards chassis section of Figure 1; Figure 4 is rear view of the rearwards chassis section of Figure 1; Figure 5 is a plan view from above of a forwards chassis section of a split-chassis load carrying vehicle according to a first preferred embodiment of the invention, having a flatbed floor for supporting a load, a movable bogie section with a set of wheels, and a front pair of drop-down supports, the forwards chassis section being suitable for joining to the rearwards chassis section of Figure 1 to form a split-chassis load carrying vehicle; Figure 6 is a cross-section view through the forwards chassis section, taken along line VI-VI of Figure 5; Figure 7 is a side view of the forwards chassis section of Figure 5; Figure 8 is a perspective view from above of the forwards chassis section of Figure 5; Figure 9 is a perspective view from below of the forwards chassis section of Figure 5; Figure 10 is rear view of the forwards chassis section - 20 of Figure 5; Figure 11 is a plan view from above of the rearwards and forwards chassis sections of Figures 1 and 5 when joined together to form a split-chassis load carrying vehicle, here a flatbed trailer; Figure 12 is a cross-section view through the split- chassis trailer, taken along line XII-XII of Figure 11, with the movable bogie section moved to be beneath the rearwards chassis section; Figure 13 is a side view of the split-chassis trailer of Figure 11; Figure 14 is a perspective view from above of the split-chassis trailer of Figure 11; Figure 15 is rear view of the split-chassis trailer of Figure 11; Figure16 is a perspective view from above of the movable bogie section; Figure 17 is a side view of the movable bogie section of Figure 16; Figure 18 is a rear view of the movable bogie section of Figure 16; Figure 19 is a plan view from above of the movable bogie section of Figure 16; 21 Figure 20 is a plan view from above of a rearwards chassis section of a split-chassis load carrying vehicle according to a second preferred embodiment of the invention, having a skeletal frame for supporting an ISO container, a fixed bogie with a set of wheels, and front and rear pairs of drop-down supports; Figure 21 is a side view of the rearwards chassis section of Figure 20; Figure 22 is a perspective view from above of the rearwards chassis section of Figure 20; Figure 23 is a plan view from above of a forwards chassis section of a split-chassis load carrying vehicle according to a second preferred embodiment of the invention, having a skeletal frame for supporting an ISO container, a movable bogie section with a set of wheels, and a front pair of drop-down supports, the forwards chassis section being suitable for joining to the rearwards chassis section of Figure 20 to form a split-chassis load carrying vehicle; Figure 24 is a side view of the forwards chassis section of Figure 23; Figure 25 is rear view of the forwards chassis section of Figure 23; Figure 26 is a perspective view from above of the forwards chassis section of Figure 23; - 22 Figure 27 is a perspective view from above of the rearwards and forwards chassis sections of Figures 20 and 23 when joined together to form a split-chassis load carrying vehicle, here a skeletal trailer having retractable mounting points for securing one or two ISO containers on the trailer, the mounting points here being retracted; Figure 28 is a perspective view similar to that of Figure 27, showing the trailer with four pairs of mounting points being extended for securing two 6.1 m ISO containers on the trailer; Figure 29 is a plan view from above of the split-chassis trailer of Figure 28; Figure 30 is a cross-section view through the split-chassis trailer, taken along line XXX-XXX of Figure 29; Figure 31 is a side view of the split-chassis trailer of Figure 29; Figure 32 is a plan view from above of the splitchassis trailer of Figure 27; Figure 33 is rear view of the split-chassis trailer of Figure 29; Figure 34 is a plan view from above of a rearwards chassis section of a split-chassis load carrying vehicle - 23 according to a third preferred embodiment of the invention, having a skeletal frame for supporting an ISO container, a fixed bogie with a set of wheels, and front and rear pairs of drop-down supports; Figure 35 is a is a crosssection view through the rearwards chassis section, taken along line XXXVXXXV of Figure 34; Figure 36 is a side view of the rearwards chassis section of Figure 34; Figure 37 is a perspective view from above of the rearwards chassis section of Figure 34; Figure 38 is a rear view of the rearwards chassis section of Figure 34; Figure 39 is a side view of the rearwards chassis section of Figure 34 showing how this may be joined to a fifth-wheel of a tractor unit by means of a king pin that extends downwardly from an axial forwards projection of the rearwards chassis section; Figure 40 is a plan view from above of a forwards chassis section of a split-chassis load carrying vehicle according to a third preferred embodiment of the invention, having a skeletal frame for supporting an ISO container, a movable bogie section with a set of wheels, and a front pair of drop-down supports, the forwards chassis section being suitable for joining to the rearwards chassis section of Figure 34 to form a - 24 split-chassis load carrying vehicle; Figure 41 is a is a cross-section view through the forwards chassis section, taken along line XLI-XLI of Figure 40; Figure 42 is a side view of the forwards chassis section of Figure 40; Figure 43 is a perspective view from above of the forwards chassis section of Figure 40; Figure 44 is rear view of the forwards chassis section of Figure 40; Figure 45 is a side view of the forwards chassis section of Figure 40 showing how this may be joined to a fifth-wheel of a tractor unit by means of a king pin that extends downwardly from a front portion of the forwards chassis section; Figure 46 is a plan view from above of the rearwards and forwards chassis sections of Figures 34 and 40 when joined together to form a split- chassis load carrying vehicle, here a skeletal trailer having fixed mounting points for securing one or two ISO containers on the trailer; Figure 47 is a cross-section view through the split-chassis trailer, taken along line XLVII-XLVII of Figure 46; - 25 Figure 48 is a side view of the split-chassis trailer of Figure 46; Figure 49 is a perspective view from above of the split-chassis trailer of Figure 46; Figure 50 is rear view of the split-chassis trailer of Figure 46; Figure 51 is a side view of the split-chassis trailer of Figure 46 showing how this may be joined to the fifth-wheel of the tractor unit by means of the king pin in the front portion of the forwards chassis section; Figure 52 is a top view of the forwards chassis section of Figure 23 showing the bogie section secured at a forwards location on the forwards chassis section, and illustrating how the rear axle spacing limits load carrying capacity; Figures 53 and 54 are, respectively, top and side views of the forwards chassis section of Figure 52 showing the bogie section secured at a rearwards location on the forwards chassis section, and illustrating how the increased axle spacing increases load carrying capacity; Figures 55 and 56 are, respectively, perspective views of the forwards chassis section of Figures 52 and 53; Figures 57 and 58 show schematically in side views how, for the various embodiments of the invention, the bogie section is moved from the rearwards chassis section to - 26 the forwards chassis section when the sections are to be disconnected; Figures 59 and 60 show schematically in side views how, for the various embodiments of the invention, the location of the bogie section when secured to the forwards chassis section is altered by means of a double pin that moves between a pair of inwardly facing claps when the bogie moves from a forwards location to a rearwards location on the forwards chassis section in order to increase the load carrying capacity; Figure 61 shows schematically in a plan view how, in Figures 59 and 60, the double pin moves between the inwardly opposed clasps) Figure 62 and 63 show, respectively, side and perspective views of the movable double pin for the various embodiments of the invention; and Figures 64 and 65 show in fragmentary perspective views how, for the forwards chassis section of Figure 23, the bogie section moves from a forwards location to a rearwards location on the forwards chassis section to increase load carrying capacity.

DETAILED DESCRIPTION

Reference is made first to Figures 1 to 4, which show various views of an elongate rearwards chassis section 2 for a split-chassis load carrying vehicle. The rearwards chassis section 2 has a flatbed floor 3 for supporting a load, a - 27 fixed bogie 8 with running gear including a set of wheels 10, and front and rear pairs 12,14 of drop-down supports The running gear, which is fixed to the rest of the rearwards chassis section 2, is conventional and so will not be further described.

The rearwards chassis section 2 has a pair of parallel longitudinal frame members 20,21 in the form of steel C-beams or I-beams that extend nearly the full length of the chassis section 2. The frame members 20,21 have a laterally outwardly directed C-form. The frame members 20,21 are supported by the fixed bogie 8 and drop-down supports 12,14, and in turn support the load-bearing floor 3. The rearward chassis section 2 also has a number of transverse frame members 24,38 that extend between or project laterally outwards from the longitudinal frame members 20,21.

A male portion 26 of an engagement mechanism extends forwards of the longitudinal frame members 20,21 centered on a longitudinal axis 30 of the rearwards chassis section 2. This rearwards portion 26 of the engagement mechanism has a tapering tip 28. A fixed pin 32 extends upwards from an upper surface 34 of the tip 28 centered on the longitudinal axis 30. The functioning of the engagement means will be further explained below.

The rearwards chassis section 2 also has a downwards extending pin 36 which, as will also be explained below, serves as a portion of a securing mechanism to secure a movable bogie to the rearwards chassis section 2. The pin 36 extends downwardly from a transverse frame member 38 that extends between the longitudinal frame members 20,21. Like v vet - 28 the upward extending pin 32, the downward extending pin 36 is also centered on the longitudinal axis 30. The central axial arrangement of the components 26,27,32 of the engagement mechanism helps to balance forces on these components both during connection and disconnection of the chassis sections 2,4 and also during operation on the road of the vehicle. The engagement mechanism is therefore referred to herein as an axial engagement mechanism.

Reference is now made also to Figures 5 to 10, which show various views of an elongate forwards chassis section 4 for a split-chassis load carrying vehicle. The rearwards chassis section 2 has a flatbed floor 5 for supporting a load, a movable bogie section 6 with running gear including a set of wheels 11, and a front pair 16 of drop-down supports. Some of the running gear such as axles and air suspension, is conventional and so will not be further described. Parts of the running gear necessary for the movement and securing of the bogie section 6 to the rearwards and forwards chassis sections 2,4 are shown in more detail in Figures 16 to 19, and will be explained in detail below.

The forwards chassis section 4 has a pair of parallel longitudinal frame members 22,23 in the form of steel I-beams or C-beams that extend the full length of the chassis section 4 towards a rearmost edge 19 of the forwards chassis section 4. The forwards frame members 22,23 have the same C-form cross-section as the rearwards frame members 20,21. The frame members 22,23 are supported by the movable bogie section 6 and front drop-down supports 16, and in turn support the load-bearing floor 5. The forwards chassis section 4 also has a number of transverse frame members 25 that extend between - 29 or project laterally outwards from the longitudinal frame members 22,23.

The forwards chassis section 4 has a female portion 27 of the engagement mechanism by which the forwards chassis section 4 may be removably joined to the rearwards chassis section 2, as shown in Figures 11 to 15. This forwards portion 27 of the engagement mechanism is centered on a longitudinal axis 31 of the forwards chassis section 4, and is in the form of a receptacle having some partially open sides 40 that lead towards a fifth-wheel type clasp mechanism 42, shown most clearly in a cut-away view in Figure 5. When the forwards chassis section 4 is rolled towards the rearwards chassis section 2, the rearwards portion 26 of the engagement mechanism enters the forwards portion 27. The fit is such that the upwards pin 32 is guided into the clasp 42 which automatically engages with the pin 32 to lock and secure the forwards section 4 to the rearwards section 2, and so form a split-chassis load carrying vehicle 1.

The rearwards and forwards floors 3,5 then provide a continuous loading surface. Optionally, the surface 3,5 has as shown in the drawings a pair of parallel grooves 43,44 that run alongside and laterally outwards from upper surfaces of the longitudinal I-beam frame members 20,21;22,23. The groves may then serve as a track for a crane (not shown) that may run the full length of the surface 3,5 for loading and unloading the vehicle.

As shown most clearly in Figures 12 and 13, the split-chassis vehicle 1 has towards the front of the forwards chassis section 4 a downwardly extending king pin 46 for connection - 30 to a fifth-wheel of a tractor unit (not shown). The vehicle 1 therefore serves as a flatbed trailer.

As shown' in Figure 16 to 19, the movable bogie section 6 has a pair of longitudinal frame members 48,49 each of which has a laterally inwardly directed C-form. A number of transverse frame members 51 extends between the longitudinal frame members 48,49, each of which has a profile in the transverse direction that matches the profile of transverse supports for the engagement mechanism 26,32;27,42 in the chassis sections 2,4. Specifically, the transverse profile has a lowered central portion 55 flanked by adjacent portions 56 that taper upwards to the level of a lower lip 57 of the bogie section longitudinal frame members 48,49.

The laterally inwardly directed C-form of the longitudinal frame members 48,49 is wider than the laterally outwardly directed C-form of the chassis longitudinal members 20,21;22,23, so that the bogie longitudinal members 48,49 cup a lower lip 49 of the chassis beams.

The arrangement is such that the rearwards and forwards pairs 20,21;22,23 of longitudinal frame members are longitudinally aligned when the chassis sections 2,4 are joined together.

This permits the movable bogie section 6 to slide between the chassis sections on rollers (not shown) mounted in housings on the chassis longitudinal frame members.

The movable bogie section 6 is initially secured to the forwards chassis section 4 by means of a securing mechanism between the bogie section and the forwards chassis section.

The securing mechanism comprises an axially movable member 35 - 31 by which the bogie section 6 may be secured to the forwards chassis section 4 at one of two axial locations along the length of the forwards chassis section.

The various embodiments of the invention will first be described in Figures 1 to 51 with the bogie section 6 located at a forwards location on the forwards chassis section 4. The description relating to Figures 52 to 65 will then describe how the bogie section 6 moves between forwards and rearwards locations on the forwards chassis section 4.

The movable double pin 35 has a first pin 50 that extends downwards from the forwards chassis section to a level beneath the longitudinal frame members 22,23, and which engages with a forwards facing clasp mechanism 52 in the movable bogie section 6 when the forwards chassis section 4 is secured to the bogie section 6.

The movable double pin 35 also has a second pin 60 that extends upwards at a level between the longitudinal frame members 22,23, and which, when the bogie section 6 is at the forwards location, is engaged with a rearwardly facing clasp 58. When the bogie section 6 is at the rearwards location, it is engaged with a forwardly facing clasp 68. Both of these clasps 58,68 are fixed to a corresponding transverse frame member 59 that extends between the longitudinal frame members 22,23.

When the forwards facing clasp 52 of the bogie section 6 is released, the downward pin 50 is free to leave the clasp 52 as the vehicle 1 is moved in a forwards direction. To facilitate this, a control system is provided which brakes - 32 the movable bogie wheels 11, but not the fixed bogie wheels as the vehicle is pulled forwards. This causes the movable bogie section 6 to slide rearwards until the rear pin 36 in the rearwards chassis section 2 enters a rear facing clasp 53 in the movable bogie section 6. As can be seen from the drawings, the bogie clasps 52,53 are similar but oppositely directed. Both clasps 52,53 lie in the same plane below the level of the axial engagement mechanism 26,27,32,42, and are centered on the longitudinal axes 30,31 of the rearwards and forwards chassis sections 2,4.

The brakes the then released on the movable bogie section wheels 11 and the vehicle may then move off.

The central axial arrangement of the components 35,58,68,52;36,53 of the securing mechanism in the rearwards and forwards chassis sections 2,4 and in the bogie section 6 helps to balance forces on the components both during locking and unlocking of the bogie section to the chassis sections 2,4 and also during operation on the road of the vehicle 1.

The securing mechanism is therefore referred to herein as an axial securing mechanism.

When the rearwards chassis section 2 is to be left behind, for example for unloading at a depot, then the axial engagement mechanism 26,27,32,42 is disengaged to allow the chassis sections 2,4 to be separated. Prior to this, the bogie section 6 is released from the rearwards chassis section 2 and moved to be beneath the forwards chassis section 4. In doing so the axial securing mechanism 36,53 between the rearwards chassis section 2 and the movable bogie section 6 is first released to allow the portion of the - 33 securing mechanism 52,53 in the bogie section to move with clearance underneath the axial engagement mechanism 26,27,32,42.

To facilitate the relative movement of the movable bogie section 6 and the chassis sections 2,4, the brakes are again applied to the movable bogie section wheels 11, but not the fixed bogie section wheels 10. The vehicle 1 moves backwards and the front pin 50 enters the front facing clasp 52. The pin 50 is automatically captured by the clasp 52, and an automatic control system releases the brakes on the movable bogie wheels 11.

An operator would then lower the front and rear supports 12, 14 in the rearwards chassis section 2, prior to disengaging the engagement means 26,27,32,42, again under the control of an automatic control system.

Although not shown in the drawings, the front pair of supports 12 in the rearwards chassis section needs to be movable out of the way of the sliding bogie section 6. This may be done either by providing a slider mechanism for the supports 12 on a laterally outwards surface of the longitudinal frame members (as will be described for the second embodiment below), or by making the supports removable.

A second embodiment of a split-chassis load carrying vehicle 101 is illustrated in Figures 20 to 33. Features in the second embodiment 101 that correspond with features in the first embodiment 1 are indicated by reference numerals incremented by 100. - 34

The split-chassis load carrying vehicle 101 of the second embodiment differs from that of the first embodiment 1 essentially in that the vehicle is a skeletal trailer for carrying containerized loads. The axial securing mechanism 136,153;135,152,158,168 and the axial engagement mechanism 126,127,132,142 work in exactly the same way as described above.

The split-chassis skeletal trailer 101 also differs in that the a slider mechanism 70 is provided by which the front drop-down supports 112 may be slid backwards towards the fixed bogie 108 when the movable bogie section 106 is moved back to be beneath the rearwards chassis section 102.

The skeletal trailer 101 is of the "Goose Neck" type with, as shown most clearly in Figures 25, 30 and 31, the longitudinal frame members 122,123 having a load bearing upper surface 105 set 160 mm below the level of a load bearing "Goose Neck" box-section chassis member 72 that extends forwards of the main longitudinal frame members 122,123.

Each of pair of chassis members 120,121;122,123 in the rearwards and forwards chassis sections 102,104 are spaced apart by several transverse load bearing tie beams 124,125,138 which provide support for nearby or adjacent corresponding pairs of container twist lock mounts 80,81,82,83',84 for connecting to various ISO standard containers.

Each one of the pairs of mounts 80, 81, 82, 83', 84 may be moved between a retracted orientation, as indicated by primed - 35 reference numerals 80', 81', 82', 83' as shown in Figure 27 to a laterally extended orientation, as indicated by unprimed reference numerals 80,81,82,84 as shown in Figure 28.

The operation and use of such retractable mounts in a "Goose Neck" skeletal trailer is discussed in patent document WO 03/011636 Al. This disclosure explains how such container mounts may be retracted or extended as required in order to load a variety of container configurations onto a skeletal trailer. The arrangement of the axial engagement mechanism and the axial securing mechanism of the present invention is compatible with the low vertical height afforded by such a "Goose Neck" trailer, with the result that the skeletal trailer 101 is capable of carrying "High Cube" containers on continental European roads with the standard super single 385 x 65 x R22.5 tyre size.

Furthermore, because the invention employs a movable bogie section 106, thus saving on unloaded weight, the skeletal "Goose Neck" trailer 101 is capable of carrying "Heavy" type containers and fully loaded 13.6 m (45 feet) containers on United Kingdom roads.

Both the first and section embodiments 1,101 provide a bogie section 6, 106 which can be located at one of two positions on the forwards chassis section 4,104, as will be explained in further detail below with reference to Figures 52 to 65.

Both the first and second embodiments 1,101 of the invention also provide a low-height for a loading surface, either a flatbed surface 3,5 or containerized mounted points 80-84. As can be seen most clearly from Figures 25 and 33 the - 36 arrangement of the axial securing mechanism and the axial engagement mechanism provides significant benefits, as the clasps 52,53;152,153 in the moving bogie section 6i106 have a lower profile than the downwardly extending pins 36, 50;136, 150 in either of the chassis sections 2,4;102;104.

Because the low profile components (i.e. the clasps) are provided in the moving bogie section, more vertical clearance is provided where the moving bogie section and the engagement mechanism cross over. This in turn helps to keep the overall height of the vehicle down, and permits the vehicle to carry higher loads or taller containers than would otherwise be the case.

A third embodiment of a split-chassis load carrying vehicle 201 is illustrated in Figures 34 to 51. Features in the third embodiment 201 that correspond with features in the second embodiment 1 are indicated by reference numerals incremented by 100.

The split-chassis load carrying vehicle 201 of the third embodiment differs from that of the second embodiment 101 in that the vehicle is a skeletal trailer having fixed container mounting points 85,180,181,102, 183,184 extending outwards from parallel longitudinal frame members 220, 221,222,223.

Another difference lies in the fact that the longitudinal frame members are not of the "Goose Neck" type, but have a flat upper surface. This skeletal trailer 201 is therefore not suitable of carrying "High Cube" type containers on Continental European roads. The trailer can, however, carry all formats of ISO container on UK roads. - 37

The axial securing mechanism 236,253i235,252,258,268 and the axial engagement mechanism 226,227,232,242 of the third embodiment 201 work in essentially the same way as described above for the first and second embodiments 1,101. A significant difference, however, lies in the fact the rearwards chassis section 202 has a longer forwards projection 226 with a king pin 232 that extends downwards from a lower surface 234 of the projection 226 near the forwards tip 228 of the projection 226. The king pin 232 is identical with the upwardly extending pins 26,126 of the first and second embodiments 1,101, and engages with the same type of clasp mechanism 242 in the forwards chassis section 204 when the chassis sections 202,204 are joined together.

Compared with the first and second embodiments 1,101, the clasp mechanism 242 of the third embodiment 201 is inverted and positioned further forwards in the forwards chassis section.

As shown in Figure 39, the king pin 232 and forwards projection 226 of the rearwards chassis section 202 are suitable for connection to a conventional fifth-wheel 90 of a tractor unit 92. The rearwards section 202 may therefore be used to transport goods either as a rearwards section of a split-chassis vehicle 201, or independently of the forwards chassis section 204.

It should be noted that the split-chassis load carrying vehicle of the second and third embodiments 101,201 each differ from that of the first embodiment 1 essentially in that the vehicles 101,201 are skeletal trailers for carrying containerized loads. The axial securing mechanisms 136,153,135,152,158,258 and 236,253,235,252,258,268 and the - 38 axial engagement mechanisms 126,127,132,142 and 226,227,232,242 for the second and third embodiments 101,201 work in the same way as those for the first embodiment 1 described above.

It is also a particular benefit of the invention that the rearward chassis section 2,102,202 contains only one pin 32,132,232 as the rearwards portion of the engagement mechanism, and one downwardly extending pin 36,136,236 in the rearwards portion of the securing mechanism. Such pins are relatively simple mechanically as compared with the clasp mechanisms 42,52,53 and 152,153,142 and 242,252, 253, and are hence much cheaper to manufacture and require essentially no maintenance in use.

Similarly, the vehicles 1,101,201 according to the invention may have one relatively inexpensive movable bogie section 6;106;206 which when secured to the forwards chassis section can be located at forwards and rearwards locations on the forwards chassis section, as will now be explained below in greater detail with reference to Figures 52 to 65.

Figure 52 shows, using the example of the forwards chassis section 104 of Figure 23, how the Gross Train Weight (GTW) for a trailer is calculated in the UK. The distance between the forwards king pin 146 and the rearmost axle as measured in millimetres is multiplied by 5.5 kg. For the forwards chassis section, this is 4,570 mm x 5.5 kg = 25,135 kg GTW. A normal truck tractor unit weights around 8500 kg and a usual weight for a short trailer such as that of Figure 52 is about 4,000 kg. This would give a rather limited tare weight of about 12,635 kg, from which 2,500 kg weight for a 20 foot - 39 (6.1 m) container box must be subtracted, leaving only 10,135 kg for payload.

In contrast, as shown by Figure 54, the present invention allows the operator to legally travel with a GTW of about 32,725 kg by extending the axles of a split front trailer chassis section to a separation of 5,950 mm. Again, if it is assumed that a normal tractor unit weighs around 8,500 kg, and the forwards chassis section 104 and bogie section 106 together weigh about 4,000 kg, then the tare weight is improved to about 20,225 kg of which 2,500 is accounted for by a box container. This results in a substantial increase in permissible payload to about 17,725 kg.

It is particularly advantageous if the bogie section 106 has only a pair of axles, rather than three axles, in order to maximise the tare weight when the bogie section is secured to the forwards chassis section 104.

In use, a driver would activate a button on a control panel (not shown) first to split the trailer as described above into two separate forwards and rearwards chassis sections. In doing this, the bogie section 106 is secured at a forwards location in the forwards chassis section 104. The driver would then operate a further control to extend the forwards chassis section by moving the bogie section rearwards until at least a rearmost axle is behind the rearmost edge 119 of the forwards chassis section 104.

Figures 55 and 56 show perspective views of the forwards chassis section 104 with the bogie section 106 at, respectively, a forwards location in which the bogie section - 40 is fully forwards of the rearmost edge 119 of the forwards chassis section 104, and at a rearwards location in which the bogie section is partially rearwards of the rearmost edge 119 of the forwards chassis section 104.

Figures 57 to 60 show, schematically, how the joined chassis sections 2,4 are separated, and then the bogie section 6 moved initially from beneath the rearwards chassis section 2 to beneath the forwards chassis section 4,and then after the sections 2,4 have been disconnected, moved rearwards partially behind the rearmost edge 19 of the forwards chassis section 4. In this description, the reference numerals are those of the first embodiment 1, but of course the other two embodiments 101,201 employ the same concepts. First, in Figure 57, with the movable double pin 35 ("Shuttle") held by the clasp 58 ("Lock 3"), the rearwards clasp ("Lock 1") of the bogie section 6 is released from the rearwards section pin 36 ("Fixed King Pin") and moved from the rearwards chassis section 2 to the forwards chassis section 4 until the forwards clasp 52 ("Lock 2") of the bogie section engages with the pin 50 of the double pin 35. During this, the brakes of the bogie section wheels 11 are locked, while the brakes of the fixed bogie wheels 10 are free, allowing the driver to move the vehicle rearwards.

The driver then as shown in Figure 58 lowers manually the rear drop down legs 12 and activates the control which disengages pin 32 from the clasp 42 ("Lock 5") and which at the same time reverses the brakes, so that the sliding bogie wheels 11 are free and those 10 of the fixed bogie 8 are braked, allowing the driver to move the vehicle forwards to separate the forwards and rearwards chassis sections 4,2 as - 41 shown in Figure 59.

Finally, as shown in Figure 60, the driver activates a further control which disengages the upwards pin 60 of the movable double pin 35 from the rearwards clasp 58 ("Lock 3") and which at the same time locks the wheels 11 of the bogie section 6, allowing the driver to move the vehicle forwards to move the bogie section from the forwards location to the rearwards location at which the upwards pin 60 enters and engages with the forwards facing clasp 68 ("Lock 4"). The bogie section brakes are then automatically released, allowing the driver to pull away.

Figures 64 and 65 show in greater detail this arrangement in the case of the second embodiment 102. The travel afforded the bogie section 106 is set by the distance between the rearwards and forwards facing clasps 158, 168. An advantage of this arrangement is that the movable double pin 135, and hence the movement of the bogie section 106 when secured to the double pin 135, is constrained by the inwardly facing clasps 158,168. This eliminates the possibility of the bogie section 106 being lost completely out of the forwards chassis section 104 due to operator error. The invention therefore uses a clasp locking device and movable pin assembly in a novel way to achieve maximum security and operator simplicity.

It should, however, be noted that the bogie section could be secured to the forwards chassis at various axial locations in a variety of different ways, which are not illustrated in the drawings. For example, the movable "shuttle" could comprise, instead of an upwardly extending pin that engages with one of - 42 a pair of inwardly facing clasps, one or more laterally extendible pins, which may be engaged with any of a plurality of transversely extending holes in a longitudinal frame member. Such a pin or pins may be hydraulically retracted, and sprung loaded to engage securely with a matching hole when the bogie section is moved to an axial location at which the pin is aligned with one of such holes. Preferably, such an arrangement would have a pair of such pins which are actuated by a common hydraulic ram, and which may be transversely outwardly engaged with corresponding holes in the pair of longitudinal frame members. An advantage of this arrangement is that this provides the possibility of having more than just two axial locations for the bogie section on the forwards chassis section.

Other variations to the invention may be encompassed within the scope of the invention as claimed, For example in the first and second embodiments 1;101, the rearwards chassis section 2;102 may optionally have no fixed bogie section at all and use only the shared movable bogie section 6;106.

These possibilities allow a significant weight savings and cost savings.

It therefore is envisaged that an owner of the split-chassis vehicle 1; 101;201 may purchase several of the rearward chassis sections 2;102;202 for each forwards chassis section 4i104;204. Rearward chassis sections may then be left at depots or at delivery/collection destinations for loading and unloading while the forwards chassis section is taken elsewhere by a tractor unit. In the case of the third embodiment 201, after splitting of the forwards and rearwards chassis sections 202,204, a second tractor unit 92 may be - 43 used to transport the rearwards chassis section 202 to a different final destination from that of the forwards chassis section 204.

It is therefore very helpful for all embodiments 1;101;201 that the rearward chassis section 2;102;202 is kept as inexpensive and mechanically simple as possible.

It should be noted that either of the first or second embodiments 1,101 could be modified to have the downwardly extending king pin 246 and inverted clasp 242 of the third embodiment 201 so that the rearwards chassis section 2,102 of these embodiments could be attached to a tractor unit 90.

It should be also noted that the invention is not limited to trailers having a forwards section that may be removably joined with a tractor unit to form a vehicle with an articulated trailer. For example, the invention is equally applicable to a vehicle that has a forwards chassis section that is permanently affixed to or part of a motive unit, as long as the forwards chassis section has a bogie section which may be secured at any of a plurality of axial locations on the forwards chassis section and also on the rearwards chassis section when this is removably joined to the forwards chassis section as described above for any of the three embodiments of the invention.

Although the first and second embodiments 1,101 of the invention have been illustrated as having both a movable bogie section and a fixed bogie section in the rearwards chassis section, it may be desirable to dispense with the fixed bogie section, in which case the rearwards bogie - 44 section would be supported only by drop-down supports when separated from the forwards bogie section. This would permit the manufacture of a very inexpensive rearwards chassis section, thereby making it very economical to have a large number of such rearwards chassis sections for every forwards chassis section.

Modifications may be incorporated without departing from the scope of the present invention as claimed. For example, although the invention has been described with reference to a flatbed trailer and a skeletal trailer, the invention may also be useful for curtain sided trailers or box vans.

Claims

e e e e he e e e e e c e e e e e e e e - 45 l Claims: 1. A split-chassis

load carrying vehicle, comprising a forwards chassis section, a rearwards chassis section, said chassis sections extending along a longitudinal axis of the vehicle, and a bogie section having road- running gear including a set of road-going wheels, wherein: - the bogie section is relatively movable with respect to the forwards and rearwards chassis sections between a forwards position beneath the forwards chassis section and a rearwards location beneath the rearwards chassis section at which positions the bogie section may be secured to either the forwards chassis section or the rearwards chassis section by means of a securing mechanism; - the forwards chassis section and the rearwards chassis section are releaseably joined to each other to form the vehicle by means of an engagement mechanism which when disengaged allows said chassis sections to be separated; and - the arrangement is such that the securing mechanism allows the bogie section to be secured to the forwards chassis section at at least two axial locations along the length of the forwards chassis section.
2. A vehicle as claimed in Claim 1, in which the bogie section has one or more axles for road-going wheels, and the bogie section is securable to the forwards chassis section at one axial location in which a rearmost axle is forwards of a rearmost edge of the forwards chassis section, and is securable to the forwards chassis section at another axial . c - 46 location in which the rearmost axle is rearwards of the rearmost edge of the forwards chassis section.
3. A vehicle as claimed in any preceding claim, in which the bogie section when secured to the forwards chassis section is axially constrained between a forwardmost axial location and a rearwardmost axial location.
4. A vehicle as claimed in any preceding claim, in which in which the securing mechanism includes a longitudinally movable member and the axially movable member is fixed at one axial location on the bogie section and moves between a pair of longitudinal locations on the forwards chassis section.
5. A vehicle as claimed in any preceding claim, in which the securing mechanism includes a longitudinally movable member which when the forwards chassis section is secured to the bogie section is fixed at one longitudinal location on one of said sections and is fixed at one of a plurality of longitudinal locations on the other of said sections, the longitudinally movable member moving between said plurality of longitudinal locations when the bogie section is moved between axial locations along the length of the forwards chassis section.
6. A vehicle as claimed in any preceding claim, in which both the forwards chassis section and the bogie section have a pair of longitudinally extending frame members that extend along either side of a longitudinal axis of the vehicle, and the longitudinally movable member extends vertically between both pairs of longitudinal frame members.

e. e a.e see - 47
7. A vehicle as claimed in Claim 5 or Claim 6, in which the longitudinal movable member moves along a longitudinal axis of the vehicle, when the bogie section is moved between axial locations along the length of the forwards chassis section.
8. A vehicle as claimed in any of Claims 5 to 7, in which the longitudinal movable member includes at least one pin which engages with at least one clasp at said axial locations at which the bogie section is secured with the forwards chassis section.
9. A vehicle as claimed in Claim 8, in which the pin is a double pin that extends upwards between a pair of inwardly facing clasps in the forwards chassis section and downwards to engage with a clasp in the bogie section when the bogie section is secured to the forwards chassis section.
10. A vehicle as claimed in any preceding claim, in which the engagement mechanism comprises an axially extending projection on one chassis section that engages with a complementary feature on the other chassis section as the two sections are brought together to be joined, a portion of the securing mechanism in the bogie section moving beneath the axially extending projection as the chassis sections are to be joined or separated.
11. A vehicle as claimed in any preceding claim, in which the securing mechanism comprises a clasp mechanism in the bogie section that engages with a downwardly extending pin in the forwards chassis section and/or the rearwards chassis section as the bogie section is secured to the respective chassis section.

## ## # # # # # . # # # # # '. # # # ece # C # # # - 48
12. A vehicle as claimed in Claim 11, in which the securing mechanism comprises a pair of clasps on the bogie section and a pair of downwardly extending pins, one of said pins being on the forwards chassis section and the other of said pins being on the rearwards chassis section, the arrangement being such that as the bogie section moves between said chassis sections one of the pins is released by and moves away from one of said clasps and the other of said pins moves towards and enters the other of said clasps.
13. A vehicle as claimed in Claim 12, in which said pair of clasps each has an entrance for receiving said respective pin, said entrances facing in opposite longitudinal directions.
14. A vehicle as claimed in Claim 12 or Claim 13, in which the securing mechanism comprises a pair of clasps on the forwards chassis section, and the downwardly extending pin on the chassis section is connected to an upwardly extending pin that moves between said pair of clasps on the forwards chassis section.
15. A vehicle as claimed in Claims 14, in which each of said connected pins has an axis, said axes being aligned with one another.
16. A vehicle as claimed in Claim 14 or Claim 15, in which said pair of clasps on the forwards chassis section each has an entrance for receiving said upwardly extending pin, said entrances facing in towards each other.

. a.

- 49
17. A vehicle as claimed in any preceding claim, in which the vehicle is a flatbed trailer.
18. A vehicle as claimed in any of Claims 1 to 16, in which the vehicle is a skeletal trailer for carrying containerized loads.
19. A vehicle as claimed in any preceding claim, in which the vehicle comprises an automatic control system for controlling the separation and joining of the forwards and rearwards chassis section which, when the rearwards chassis section is to be separated from the forwards chassis section, the control system being arranged to: a) apply a brake to the wheels of the bogie section; b) release the securing mechanism to disengage the bogie section from the rearwards chassis section; c) permit the vehicle to move in a reverse direction with the bogie section remaining stationary until the securing mechanism engages with the forwards chassis section; and d) release the engagement mechanism after the bogie section has been supported by drop down legs on the bogie section.
20. A vehicle as claimed in Claim 19, the vehicle comprising an automatic control system for controlling the securing of the bogie section to the forwards chassis section at said at least two axial locations along the length of the forwards chassis section, in which following separation of said chassis section said control system is arranged to: c - c. c r .

C C C 50

f) apply a brake to the wheels of the bogie section) g) release the securing mechanism to disengage the bogie section from the forwards chassis section at one of said axial locations; and h) permit the vehicle to move in a either a reverse direction or a forwards direction with the bogie section remaining stationary until the securing mechanism engages with the forwards chassis section at another of said axial locations.
21. A motive vehicle for carrying a load, comprising a tractor unit in combination with a split-chassis load carrying vehicle, said splitchassis load carrying vehicle being as claimed in any preceding claim.
22. A forwards chassis section for connection to a rearwards chassis section to form a split-chassis vehicle, said forwards chassis section comprising: - a bogie section having road-running gear including a set of road-going wheels, the bogie section being engaged to the forwards chassis section by means of a securing mechanism; - a portion of an engaging mechanism by which the forwards chassis section may be releaseably engaged with a rearwards chassis section to form the split-chassis vehicle; wherein - the bogie section is movable in a longitudinal direction with respect to the forwards chassis section towards a I c : ce. : :::.

e ee e - Al - rearwards chassis section when the securing mechanism is released; and - the securing mechanism allows the bogie section to be secured to the forwards chassis section at at least two axial locations along the length of the forwards chassis section
23. A method of forming a split-chassis load carrying vehicle, said vehicle comprising a forwards chassis section, a rearwards chassis section, said chassis sections extending along a longitudinal axis of the vehicle, a bogie section releaseably secured to the forwards chassis section at one of a plurality of axial locations by means of a securing mechanism and having road-running gear including a set of road-going wheels, and an engagement mechanism for releaseably engaging said chassis sections together, the method comprising when the bogie section is not secured to the forwards chassis section at a forwardmost axial location the steps of: i) braking the wheels of the bogie section and releasing the securing mechanism to free the bogie section for relative sliding movement with respect to said forwards chassis section; ii) backing the forwards chassis section in a rearwards direction with the bogie section stationary until the bogie section is secured to the forwards chassis section at a forwardmost axial location; iii) releasing the braking of the wheels of the bogie section; eesees ese c:. eve:.: en: 52 iv) backing the forwards chassis section towards the rearwards chassis section make the engagement mechanism engage said chassis section together and thereby join said chassis sections together; v) braking the wheels of the bogie section and releasing the securing mechanism to free the bogie section for relative sliding movement with respect to said joined chassis sections; and vi) moving said joined chassis sections forwards with the bogie section stationary until the bogie section is secured to the rearwards chassis section by means of the securing mechanism.
24. A split-chassis load carrying vehicle, substantially as herein described, with reference to or as shown in: Figures 1-19; or Figures 20-33 and 64-65; or Figures 34 to 56i and/or Figures 57- 63 of the accompanying drawings.
25. A motive vehicle for carrying a load, comprising a tractor unit in combination with a split-chassis load carrying vehicle as claimed in Claim 24.
26. A rearwards chassis section for connection to a forwards chassis section of a split-chassis vehicle as claimed in Claim 24.
27. A forwards chassis section for connection to a rearwards chassis section of a split-chassis vehicle as claimed in Claim 24.

e.e ce: . ce.. ::.

c:e .e:: ec. - 53
28. A method of forming a split-chassis load carrying vehicle, substantially as herein described, with reference to or as shown in: Figures 1-19; or Figures 20-33 and 64-65; or Figures 34 to 56; and/or Figures 57-63 of the accompanying drawings.