NO20160087A1

NO20160087A1 - Vehicle assembly comprising a cargo part and an undercarriage

Info

Publication number: NO20160087A1
Application number: NO20160067A
Authority: NO
Inventors: Jorn Morten Kirkeby
Original assignee: Nordcon As
Priority date: 2016-01-18
Filing date: 2016-01-18
Publication date: 2017-07-03

Abstract

Vehicle assembly, comprising a cargo part and an undercarriage, the cargo part configured for removably positioning on the undercarriage. The cargo part and the undercarriage comprising first interlocking means configured for limiting movement of the cargo part in a sideways direction on the undercarriage. The cargo part and the undercarriage comprising second interlocking means configured for limiting movement of the cargo part in a rearward direction on the undercarriage. The cargo part comprises a first abutment member, and the undercarriage comprises a second abutment member. The first abutment member configured for abutment with the second abutment member for limiting movement of the cargo part in a forward direction on the undercarriage.Vehicle assembly, comprising a cargo part and an undercarriage, the cargo part configured for removable positioning on the undercarriage. The cargo part and the undercarriage comprising first interlocking means configured for limiting movement of the cargo part in a sideways direction on the undercarriage. The cargo part and the undercarriage comprising second interlocking means configured for limiting movement of the cargo part in a rearward direction on the undercarriage. The cargo part comprises a first abutment member, and the undercarriage comprises a second abutment member. The first abutment member configured for abutment with the second abutment member for limiting movement of the cargo part in a forward direction on the undercarriage.

Description

Vehicle assembly comprising a cargo part and an undercarriage

Field of the invention

The invention concerns a vehicle assembly comprising a cargo part and an undercarriage, and more specifically, a vehicle assembly where the cargo part is configured for removably positioning on the undercarriage, as set out by the preamble of claim 1.

Background of the invention

Containers are widely used for storage and transport of goods, garbage, gravel, material and anything imaginable. A type of container for such use is a hook container. A hook container is a container which is fixed, in most cases welded, onto a hook lift frame. The hook lift frame should fulfil certain requirements defined in among other Svensk Standard SS 3021, and comprises a lifting bar which can be hooked onto lifting gear when tilting or lifting the hook container. The container itself can have various shapes and sizes, also define in various standards.

When the hook container is to be transported on road, a lifting crane is connected to the lifting bar of the hook lift frame, and the container is lifted and hauled onto the truck or vehicle. Such a lifting crane is most commonly mounted on the truck. If the truck is to transport more than one hook container, the second hook container is transported on a trailer. On the trailer, the hook lift frame part of the container rests in corresponding grooves on a chassis or tip frame, and as such sideways movement of the hook container when the truck and trailer is moving is prevented. The hook container on the trailer is commonly secured to the trailer by means of two pegs on the rear end of the trailer which interconnects with the container frame at the rear end of the container. This interconnection prevents the hook container from moving rearwards when on the trailer. Pneumatic actuated pins on the sides of the trailer secure the hook container to the trailer by penetrating the frame, and thus prevent forward movement of the hook container.

Because the pneumatic actuated pins are manually actuated by an operator or other personnel, it is a source of risk that the operator forgets to activate the pins after the hook container has been placed onto the trailer. Also, in case of malfunction, it is not obvious for the operator whether the pneumatic pins have secured the hook container or not. Without the pins activated, there are no physical barriers preventing the hook container from moving forward on the trailer. Such forward movement could be caused by the trailer braking heavy, in a collision or other accident, while driving down a steep declining hill, or under other circumstances. Even if the pins are activated, the pins and the receiving pin holes are exposed to significant wear and tear as the hook container is forced forwards and rearwards while resting on the trailer. Such movement can result in fatigue and even break or damage the pneumatic mechanism and the pins, resulting in a less than adequate securing of the hook container on the trailer.

The hook container can also be secured to the trailer by means of a metal chain anchored from the trailer to the lifting bar of the container, but this method of securing is not capable to withstand the forces from a fully loaded container in the event of a rapid deceleration, like in the event of a crash or similar.

There is therefore a need in the art for a device which easily and safely secures a hook container to the trailer part of a vehicle, without håving to rely on manual activation, and which is not as exposed to wear and tear as the standard pneumatic actuated pins. The applicant has devised a safety device which secures the container on the trailer once the hook container is properly placed on a trailer, and which will prevent the hook container from unwanted movement on a trailer.

Summary of the invention

The invention is set forth andcharacterized inthe main claim, while the dependent claims describe other characteristics of the invention.

It is thus provided a vehicle assembly, comprising a cargo part and an undercarriage, where the cargo part is configured for removably positioning on the undercarriage. The cargo part and the undercarriage comprise first interlocking means configured for limiting movement of the cargo part in a sideways direction on the undercarriage, and the cargo part and the undercarriage comprise second interlocking means configured for limiting movement of the cargo part in a rearward direction on the undercarriage. The cargo part comprises a first abutment member, and the undercarriage comprises a second abutment member, the first abutment member configured for abutment with the second abutment member for limiting movement of the cargo part in a forward direction on the undercarriage.

According to one embodiment, the first abutment member is fixed to the cargo part.

According to another embodiment, the second abutment member is fixed to the undercarriage.

According to another embodiment, the cargo part is automatically limited from movement in a forward direction on the trailer part.

According to another embodiment, the first abutment member comprises a first forward contact surface configured for contacting a second forward contact surface of the second abutment member.

According to another embodiment, the first abutment member comprises a first rearward surface configured for contacting a second rearward contact surface of the second abutment member.

According to another embodiment, the first abutment member is positioned on longitudinal beams on the cargo part.

According to another embodiment, the second abutment member is positioned adjacent to grooves on the trailer part.

According to another embodiment, the second abutment member comprises a side surface which is generally level with a groove side surface of the groove.

According to another embodiment, the first abutment member is welded to the cargo part.

According to another embodiment, the second abutment member is welded to the trailer part.

According to another embodiment, at least a portion of the first abutment member is wedge shaped.

According to another embodiment, at least a portion of the second abutment member has a shape corresponding to at least a portion of the first abutment member.

According to another embodiment, the cargo part is a hook container.

According to another embodiment, the undercarriage is a trailer.

Brief description of the drawings

These and other characteristics of the invention will become clear from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached schematic drawings, wherein: Figure 1 is a side view of a trailer with a hook lift frame and hook container on top. A detail view shows an enlarged view of the safety device. The frame part of the safety device is fixed to the hook lift frame and the trailer part is fixed to the trailer. Figure 2a is a side view of the two components constituting the safety device, separated. Figure 2b is a perspective view of the two components constituting the safety device, connected. Figure 3 is a perspective view of a hook lift frame of a hook container, with the frame part of the safety device mounted thereto. Figure 4 is a perspective view of an upper part of a trailer, with the trailer part of the safety device mounted thereto.

Detailed description of a preferential embodiment

The following description may use terms such as "horizontal", "vertical", "lateral", "forward", "rearward", "upper", "lower", "inner", "outer", "foremost", "rear", etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader's convenience only and shall not be limiting. For reasons of clarity, all figures indicate a two- or three-dimensional coordinate system indicated with x-, y- and z-axes, wherein these axes are perpendicular to each. A xy-plane is spanned by the x- and y-axis, an xz-plane is spanned by the x- and z-axis, and an yz-plane is spanned by the y-and z-axis. The direction of the positive X-axis is referred to as a forward direction, and the direction of the negative X-axis is referred to as a rearward direction. Sideways direction is referred to as direction along the Z-axis.

A hook container 1 is illustrated with broken lines in figure 1. The hook container 1 can have various shapes and sizes, and is commonly made of metal. A hook container 1 comprises generally four sides and a bottom part, and is open to the air on the upper part, such that goods to be transported in the hook container lean be loaded into the container from the top. A container can also have a top part, with access into the container through doors or openings on the rear or front part, or on the sides, of the container. The hook container 1 is welded to a hook lift frame 2, also shown with broken lines in figure 1. The hook lift frame 2 extends below the bottom of the hook container 1 and usually up on at least one side of the hook container 1. In figure 1, the hook lift frame 2 extends below the hook container 1 and up in a vertical manner on the lefl; side of the hook lift container 1. The hook lift frame 2 is designed to comply with certain standards, such as Svensk Standard SS3021. As the hook lift frame 2 is welded to the hook container 1 they act as one cargo part which can be lifted, transported, etc.

When the hook container 1 is to be transported on a trailer 3, it is lifted up and positioned on the trailer 3. The hook lift frame 2 provides as such the interface between the hook container 1 and the trailer 3. In figure 1, the hook container 1 and hook lift frame 2 sits on top of the trailer 3. The trailer 3 is interconnected to a truck which can transport it to the desired location. In figure 1, when connected to a truck which is moving straight forward, the trailer 3 will move in a direction along the positive X-axis indicated in the figure.

A safety device 4 secures the hook lift frame 2 to the trailer 3. The safety device 4 is shown in an enhanced detail view in figure 1 and comprises a frame part 5 which is welded to the hook lift frame 2, and a trailer part 6 which is welded to the trailer 3. When the hook lift frame 2 (and the hook container 1) is lowered onto the trailer 3 and positioned correctly, the frame part 5 of the safety device 4 will be accommodated in the trailer part 6. As the trailer part 6 is welded to the trailer 3, it will thus automatically prevent movement of the frame part 5 in a direction generally corresponding to the X-axis. As the frame part 5 is welded to the hook lift frame 2, it prevents movement of the hook lift frame 2 relative to the trailer 3 in the X-direction. The weight of the hook container 1 and hook lift frame 2 maintains the frame part 5 securely in the trailer part 6. The safety device 4 thus limits movement of the container 1 in a direction along the X-axis, relative to the trailer 3.

The position of the safety device 4 relative to the trailer 3 along the X-axis in figure 1 is indicated by LI. The length LI indicates the distance from the rear of the trailer chassis 3 or tip frame to where the frame part 5 is welded to the hook lift frame 2, and the distance from the rear of the trailer 3 to where the trailer part 6 is welded to the trailer 3. On the safety device 4, this distance is measured from the centre of the contact area between the frame part 5 and the trailer part 6, this position is indicated with a stapled line in the detail view in figure 1, and is the centre portion where a frame part contact surface (8) will contact a trailer part contact surface (10), these surfaces are described in detail with reference to figure 2a. If the length LI is between approximately 5600 and 5750mm, and more preferably approximately 5700mm, the safety device 4 can be mounted and accommodated on most hook lift frames 2 and trailers 3, and different containers 1 with hook lift frames 2 can be secured to different trailers 3. A container comprising the frame part 5 can also be accommodated and transported on the truck.

Figure 2a shows the safety device 4 isolated, seen from the side. The frame part 5 is shown a distance apart from the trailer part 6 for illustrating purposes. When the hook lift frame rests on the trailer, the frame part 5 and trailer part 6 will be merged, as illustrated in the detail view of figure 1.

The frame part 5 comprises a peak surface 7 which in the illustrated embodiment is a flat portion. The peak surface 7 defines a lower portion of the frame part 5, and connects the frame part contact surface 8 and the frame part rear surface 9 of the frame part 5. The frame part contact surface 8 is positioned on the forward side of the peak surface 7, i.e. on the side positioned in the positive X-direction of the peak surface 7 in figure 2a. The frame part rear surface 9 is correspondingly positioned on the rear side of the peak surface 7, i.e. on the side positioned in the negative X-direction of the peak surface 7 in figure 2a.

The frame part contact surface 8 and frame part rear surface 9 extend in an inclined manner from the peak surface 7, such that at least a lower portion of the frame part 5 is generally wedge-shaped. This wedge-shape will contribute to guiding the frame part 5 into the receiving trailer part 6, when the hook container is positioned onto the trailer. If the hook container is not properly positioned on the trailer the frame part 5 will not be accommodated in the trailer part 6, and it will be both visible and obvious for the operator of the hook container that the hook container is not properly positioned.

The frame part contact surface 8 could extend in a generally vertical direction (i.e. in a direction generally corresponding to the Y-axis in figure 2a), or it could even be a curved portion or a stepped portion with different inclinations, but a straight portion with slight inclination is preferred. The inclination could be 0-45° relative to the Y-axis, more preferably between 5-20° relative to the Y-axis. The inclination should be sufficient such that movement in the positive X-direction of the frame part 5 and thus the hook container is prevented (i.e. an inclination of the frame part contact surface 8 as close to vertical as possible is desired), but the inclination should also allow the frame part 5 to be adequately accommodated into the trailer part 6 (i.e. a slight inclination of the frame part contact surface 8 is preferred).

When the trailer or vehicle and trailer is moving in a forward direction (i.e. in the positive direction of the X-axis) and suddenly decelerates, the capability to prevent movement in the positive X-direction of the frame part contact surface 8 relative to a corresponding trailer part contact surface 10 on the trailer part 6 is important in order to distribute the kinetic energy from the hook container and frame part 5 into the trailer part 6 and the trailer, and as such prevent the hook container from continuing in a forward direction and thus slide off the trailer. A top surface 14 defines the topmost portion of the frame part 5 and, in this embodiment, also the safety device 4.

The same properties describing the frame part contact surface 8 are also applicable for the frame part rear surface 9, the inclination being in the opposite direction, as is obvious from figure 2a. The frame part rear surface 9 allows for a slightly greater inclination than the frame part contact surface 8, preferably between 10-40° relative to the Y-axis, because the forces (generally acting in the X-direction) from the hook container applied through the frame part rear surface 9 will not be as strong, and will not play as an important role during the event of an crash or similar. A bigger inclination of the frame part rear surface 9 will thus allow for easier entering of the frame part 5 into the trailer part 6, without affecting the friction in the positive X-direction between the two parts. In the event of a significant deceleration of the trailer and trailer moving in a forward direction, basically no forces will be led through the frame part rear surface 9 to the corresponding trailer part rear surface 11.

The trailer part 6 comprises a sunk surface 12 which in the illustrated embodiment is a flat portion. This surface could have a corresponding shape as that of the peak surface 7 of the frame part 5, but need not. The peak surface 7 should not rest on the sunk surface 12 when the frame part 5 is merged with the trailer part 6, and as such the sunk surface 12 merely connects the trailer part contact surface 10 and the trailer part rear surface 11. The trailer part contact surface 10 is positioned on the forward side of the sunk surface 12, i.e. on the side positioned in the positive X-direction of the sunk surface 12 in figure 2a. The trailer part rear surface 11 is correspondingly positioned on the rear side of the sunk surface 12, i.e. on the side positioned in the negative X-direction of the sunk surface 12 in figure 2a. A bottom surface 15 defines the bottom portion of the trailer part 6 and, in this embodiment, the safety device 4.

The trailer part contact surface 10 and trailer part rear surface 11 have shapes generally corresponding to the shape of the frame part contact surface 8 and frame part rear surface 9, respectively. When the hook lift frame is positioned on the trailer, and the frame part 5 is resting in the trailer part 6, the frame part contact surface 8 should be in close proximity to the trailer part contact surface 10. In one embodiment, the trailer part 6 comprises only a trailer part contact surface 10 but not a dedicated trailer part rear surface 11. This will prevent the container from moving forwards on the trailer. However, in order to minimize movement of the hook container in both the positive and negative X-direction, and thus prevent wear and tear of the pneumatic pins, there should also be a trailer part rear surface 11 on the trailer part 6, and this surface should be in close proximity to the frame part rear surface 9 of the frame part 5 in order to prevent too much movement of the container in the X-direction.

In order to withstand the forces generated from a fully loaded hook container in the event of a crash, the frame part 5 must be sufficiently dimensioned. The safety device 4 is preferably made from metal, more preferably steel, and more preferably a high strength steel. The frame part 5 and trailer part 6 is preferably made from the same material, but need not be. The frame part 5 should be properly dimensioned, i.e. the material length L2 (defined from the frame part contact surface 8 and extending in the negative X-direction to the frame part rear surface 9) should be such that the frame part 5 is not deformed in the event of a crash. Correspondingly, the trailer part 6 should be properly dimensioned, i.e. the material length L3 (defined from the trailer part contact surface 10 and extending in the positive X-direction towards a front surface 13) should be such that the trailer part 6 is not deformed in the event of a crash. The foremost part of the trailer part 6 should thus have a greater length than the rear part of the trailer part 6, because this portion of the trailer part 6 must withstand forces generated in the event of a crash.

Figure 2b shows the safety device 4 isolated. The frame part 5 and trailer part 6 are in the figure merged, i.e. this illustrates the position when the hook container is properly positioned on the trailer 3. The safety device 4 can e.g. be cut from a plate material, such that the frame part 5 and trailer part 6 have equal thickness. The thickness is defined as the dimension of the safety device 4 in the Z-direction in figure 2b. The safety device 4 need not be cut from a plate, or even have a homogenous thickness, but preferably at least one frame part side surface 16 generally in the XY-plane and at least one trailer part side surface 17 generally in the XY-plane is generally level, such that the parts 5,6 can be adequately fixed to the hook lift frame 2 and trailer 3, respectively. This is described in further detail with reference to figure 3 and 4. The frame part 5 in the shown embodiment comprises two, generally parallel sides, and the trailer part 6 also comprises two, generally parallel sides.

The thickness of the parts 5,6 must be sufficient such that the safety device 4 do not deform during the event of a crash or fast deceleration of the trailer. A thickness between 10 to 30mm has been found to be sufficient, and more preferably a thickness of 15-20mm. The thickness of the frame part 5 and trailer part 6 is also dependent on the length L2 and L3 from figure 2a, if the thickness of the frame part 5 is reduced, the length L2 must be increased in order to have the same strength, and vice versa. If the thickness of the trailer part 6 is reduced, the length L3 must also be increased in order to maintain the same strength, and vice versa.

Figure 3 shows the frame part 5 mounted on the inside of a longitudinal beam 18 of the hook lift frame 2. Although not shown in figure 3, a hook container would be positioned on top, and welded onto, the hook lift frame 2. A frame part 5 is positioned in a corresponding manner on the inside of both the longitudinal beams 18, but only one frame part 5 is visible in figure 3. As the frame parts 5 are made of steel, the parts are easily welded to the longitudinal beams 18, but could also be glued, riveted or in other ways known in the art interconnected with the beams 18. It is important that the frame part 5 is adequately fixed to the hook lift frame 2, as the frame part 5 could be exposed to strong forces during the event of a crash. As mentioned above with reference to figure 2a, at least one frame part side surface 16 (in the XY-plane) should be generally level, this being the side of the frame part 5 which contacts the longitudinal beam 18. It is as such advantageous if the frame part 5 is generally level on both sides, as the frame parts 5 thus are generally identical and being accommodated to fit onto longitudinal beams 18 on both sides.

The top surface 14 (described with reference to figure 2a) of the frame part 5 is generally parallel and level with the upper beam surface 19 of the longitudinal beam 18, but need not be. There should be enough room such that a welding groove could be placed along the top of the frame part 5, fixing it to the hook lift frame 2. If the frame part 5 extends almost all the way up to the upper beam surface 19, the height of the side surface 16 (described with reference to figure 2b) of the frame part 5 is as high as possible, and results in increased strength of the frame part 5. The frame part 5 must be designed such that it can both withstand forces from an accident, and be adequately fixed to the longitudinal beam 18.

The container and hook lift frame 2 is supported on wheels 24 when the container is lifted and hauled. The wheels 24 roll on the trailer when the container is positioned onto the trailer. When the container is correctly positioned on the trailer, two pegs on the trailer (discussed below with reference to figure 4) are received in the holes 25, located at the rear of the hook lift frame 2. This interaction prevents the hook lift frame 2 and the container from moving rearward on the trailer, and also prevents the hook lift frame 2 and container from movement upwards, i.e. in a direction along the positive Y-axis. Figure 4 illustrates the top of a trailer chassis 3. This could also be the top of a tip frame or similar. The top of the trailer 3 comprises grooves 20 which extend generally in a direction along the X-axis in figure 4, this axis corresponds to the X-axis in figure 1, i.e. in the direction in which the trailer will move when moving in a straight forward/rearward direction. The two longitudinal beams of the hook lift frame are positioned into the grooves 20 when it is positioned on the trailer 3, and as such sideways movement of the container on the trailer 3 is prevented or limited. The grooves 20 have width, length and depth which could be dimensioned to comply with among others Svensk Standard SS3021, such that any hook lift frame can be placed on any trailer 3 designed according to the same standard. The top of the trailer 3 is basically symmetri cal about an XY-plane positioned in the centre of the trailer.

The trailer part 6 of the safety device is welded onto the centre surface 21 of the trailer 3, or in other ways known in the art interconnected to the trailer 3, next to the grooves 20. The trailer part 6 should be positioned close to the grooves 20 in order to not obstruct the container. As there are two grooves 20, two generally identical trailer parts 6 can be mounted. The trailer part 6 is mounted on the inside of the groove 20, in order to not obstruct the wheels of the hook lift frame. The two sets of trailer parts 6 need not be identical, but with respect to production, mounting and use, it is more convenient to utilize two similar sets of the safety device and trailer parts 6. More than two sets of the safety device could also be used, and, if the trailer part 6 and frame part of the safety device is dimensioned adequately, one safety device could be enough. However, two sets of the safety device (i.e. two trailer parts 6) are preferred.

The trailer part 6 is positioned such that the side surface 17 is generally parallel and preferably level with a vertical surface 22 of the groove 20. The vertical surface 22 should be in close proximity to the inside of the longitudinal beam of the hook lift frame when the hook lift frame is positioned on the trailer 3. As such, the frame part on the hook lift frame will contact the trailer part 6 on the trailer 3 when the container is positioned on the trailer. When the container is positioned on the trailer, the container is therefore automatically limited from movement in the forward direction on the trailer.

On the rear part of the trailer 3 are pegs 23 onto which the hook lift frame is entered, and as such positions the hook lift frame in the correct position along the X-axis on the trailer 3. The pegs 23 and the adjacent structure of the trailer 3 prevent the container from moving rearwards on the trailer.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive, and it is not intended to limit the invention to the disclosed embodiment. It should be understood that modifications and/or additions can be made to the safety device, but these shall remain within the field and scope of the invention.

Claims

1. Vehicle assembly, comprising a cargo part (1, 2) and an undercarriage (3), the cargo part (1, 2) configured for removably positioning on the undercarriage (3), the cargo part (1, 2) and the undercarriage (3) comprising first interlocking means (18, 20) configured for limiting movement of the cargo part (1, 2) in a sideways direction on the undercarriage (3), the cargo part (1, 2) and the undercarriage (3) comprising second interlocking means (25, 23) configured for limiting movement of the cargo part (1, 2) in a rearward direction on the undercarriage (3),characterized in thatthe cargo part (1, 2) comprises a first abutment member (5), and the undercarriage (3) comprises a second abutment member (6), the first abutment member (5) configured for abutment with the second abutment member (6) for limiting movement of the cargo part (1, 2) in a forward direction on the undercarriage (3).

2. The vehicle assembly according to claim 1, where the first abutment member (5) is fixed to the cargo part (1,2).

3. The vehicle assembly according to claim 1 or 2, where the second abutment member (6) is fixed to the undercarriage (3).

4. The vehicle assembly according to any one of the preceding claims, where the cargo part (1, 2) is automatically limited from movement in a forward direction on the undercarriage (3).

5. The vehicle assembly according to any one of the preceding claims, where the first abutment member (5) comprises a first forward contact surface (8) configured for contacting a second forward contact surface (10) of the second abutment member (6).

6. The vehicle assembly according to any one of the preceding claims, where the first abutment member (5) comprises a first rearward surface (9) configured for contacting a second rearward contact surface (11) of the second abutment member (6).

7. The vehicle assembly according to any one of the preceding claims, where the first abutment member (5) is positioned on longitudinal beams (18) on the cargo part (1, 2).

8. The vehicle assembly according to any one of the preceding claims, where the second abutment member (6) is positioned adjacent to grooves (20) on the undercarriage (3).

9. The vehicle assembly according to claim 8, where the second abutment member (6) comprises a side surface (17) which is generally level with a groove side surface (22) of the groove (20).

10. The vehicle assembly according to any one of the preceding claims, where the first abutment member (5) is welded to the cargo part (1, 2).

11. The vehicle assembly according to any one of the preceding claims, where the second abutment member (6) is welded to the undercarriage (3).

12. The vehicle assembly according to any one of the preceding claims, where at least a portion of the first abutment member (5) is wedge shaped.

13. The vehicle assembly according to any one of the preceding claims, where at least a portion of the second abutment member (6) has a shape corresponding to at least a portion of the first abutment member (5).

14. The vehicle assembly according to any one of the preceding claims, where the cargo part (1, 2) is a hook container.

15. The vehicle assembly according to any one of the preceding claims, where the undercarriage (3) is a trailer.