LOAD PUSHING OR LOAD STOPPING ASSEMBLY

TECHNICAL FIELD

This invention relates to a security arrangement for a load carrying, load pulling, load pushing or load stopping assembly connected to a vehicle, comprising an energy absorbing function to reduce the risk of hazard in connection with a vehicle suddenly decelerating, e.g. crashing, that carries a load, e.g. a roof rack with a roof box. BACKGROUND

There exist many situations where a load carried by a vehicle may cause damages upon sudden deceleration, e.g. when a vehicle is crashing. Due to the high energy that has been gained by the load due to the speed sudden deceleration may cause attachment members between the vehicle and the assembly carrying the to break, e.g. disrupt, which may cause severe damages. One typical example that may be referred to is a car having a roof box carried on top of a roof rack.

Severe disasters have been caused by heavy loads on roof racks that in connection with sudden deceleration of vehicles, e.g. crash, have loosened from their attachments to the roof rack. For instance, roof boxes have been causing disasters in this manner. As is well known, roof boxes may enclose a very large volume and accordingly it is possible to put a lot of load into a roof box. In connection with a crash, or other sudden deceleration, there is a risk that the attachment members keeping the roof box in place on the roof rack may be over-strained and rupture. In such a situation the roof box will continue to travel at high speeds along an uncontrolled trajectory, thereby risking to destroy and/or injure objects and/or people within that trajectory.

From WO2008/076037 there is known an arrangement intended to minimize the above risk, which is based on a specifically designed attachment between a holder of a roof rack and a bracket attached onto the roof of the vehicle. However, such an arrangement does not eliminate or reduce the risk that at large impact the attachment devices keeping the load e.g. roof box, onto the roof rack may rupture. From DE4028433 and DE102015113689 it is known to supplement a roof rack assembly with energy absorbing devices in order to reduce hazard upon sudden deceleration. However, these designs present some essential disadvantages. One major disadvantage is that the energy absorbing device is complicated to install and is of need of specifically designed inter-fitting details.

SUMMARY OF THE INVENTION

It is an object of the invention to eliminate or at least reduce the above-mentioned problem which is achieved in accordance with a solution as defined in claim 1.

Thanks to the invention there is provided an energy absorbing means for a load carrying, load pulling, load pushing or load stopping assembly that is connected to a vehicle, which may eliminate disastrous consequences in connection with sudden decelerations, e.g. crashes, and which may easily be installed in a flexible manner in various assemblies and easily maintained.

In one application it may relate to a load carrying assembly on a vehicle carrying a load in the form of a roof box, or similar device, which will absorb energy in a controlled manner at impact which in turn will decrease the strain excerpted on, or applied to, the attachment devices between the load and the vehicle. Accordingly, the risk of rupture of the attachment is thereby significantly reduced, which may save lives and eliminate or decrease possible damages. In another application it may relate to a load pulling assembly connected to a vehicle, wherein the security arrangement according to the invention may eliminate a rupture of the coupling between the load pulling vehicle and the load that is pulled, e.g. in the form of a trailer, wherein e.g. the vehicle is arranged with a tow bar. Preferably the load pulling assembly comprises a bar structure that is securely fixed to the pulling vehicle, wherein the security arrangement is connected in between the bar structure and the actual coupling part, e.g. towing ball. In another application according to the invention it may relate to a vehicle pushing a load wherein the security arrangement may eliminate rupture between a coupling between the pushing vehicle and the pushed load, e.g. a train pushing a wagon. In another application it may relate to a vehicle in the form of a moveable device in a machine which is arranged with a load stop assembly, wherein the security arrangement may eliminate rupture of the attachment between the ground and the stop member of the machine. The basic principle of the solution according to the invention includes the use of two plates guided in the longitudinal direction of the vehicle. The guidance of the two plates is such that movement preferably is nearly impossible in the longitudinal direction, i.e. a relative movement between the plates in the longitudinal direction. The two plates are interconnected by means of an energy absorbing member, preferably the energy absorbing member is such that it will not allow any substantial relative movement between the plates at a force below a predetermined level, at a force above said predetermined level the energy absorbing member will be deformed, preferably prolonged, and as a consequence of the force acting there upon due to the deceleration force and preferably at least a portion of the energy will be transformed to permanent deformation of said energy absorbing member. In this manner, a predetermined relative movement, such as a maximal prolongation of the energy absorbing member, between the two plates may be achieved. In a preferred embodiment the energy absorbing member is made of a ductile material, e.g. a metal shaped to enable deformation parallelly with the longitudinal direction, i.e. enable prolongation in said longitudinal direction according to some examples.

Even more preferred the energy absorbing member may be replaced by a new member after having been prolonged. According to further aspects of the invention: said interconnected guiding members (11/12, 20/21) include protruding parts (11,20), preferably rib shaped, which form a gap (G) between the plate shaped parts of said plates (1, 2) that provides space for said energy absorbing member (3), which provides the advantage that the energy absorbing member may be contained in between the plates without any clamping forces acting thereon from any of the plates.

- said energy absorbing member (3) is in the form of a shaped body that may be prolonged in connection with exercise of a force (F _max ), or application of the force, onto the carrier plate (1) that exceeds the predetermined level, which provides the advantage that the energy absorbing member will be unaffected in connection with a small force, i.e. the small force is smaller than the

predetermined level, acting thereon, wherein preferably said absorbing member

(3) includes at least one S-shaped part, more preferred a plurality of S-shaped parts connected to each other along said longitudinal direction (C).

the maximal prolongation (AL _max ) of said body (3) from its nominal length (Lo) to a maximum (L _max ) is at least 50% of said nominal length (Lo), preferably at least 100% of said nominal length (Lo), more preferred at least 150% of said nominal length (Lo), which provides the advantage that energy may be absorbed in a gentle manner, wherein preferably more than 50% of the energy being absorbed is ductile, i.e. in the form of permanent deformation of said energy absorbing member, and more preferred said body is shaped to have an increasing energy absorbing effect during prolongation.

at least, the main part of the energy absorbing member (3) is positioned between the two pairs of parallelly arranged ribs (11, 20), in a longitudinal channel space formed between the pairs of ribs (11, 20), which provides the advantage that the energy absorbing member may be kept in a protected manner, synergistically by means of the guiding members, wherein preferably the height (g) of said channel space is smaller than the gap (G) between said plates (1, 2).

Further aspects and details of the invention will become apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in more detail with reference to the enclosed figures, wherein; Figure 1 shows a schematic view of a vehicle with a roof rack carrying a roof box, and wherein a security assembly according to the invention, in a perspective view,

Figure 2 shows the assembly according to the invention in a perspective view,

Figure 3 shows the assembly according to the invention in a side view,

Figure 4 shows a further embodiment of the assembly according to the invention in a perspective view,

Figure 5 shows a perspective view of further alternative embodiments of the safety arrangement according to the invention,

Figure 6 is the same view as shown in figure 5 wherein the upper plate has been removed, and,

Figure 7 shows a side view of the device of figures 5 and 6 along a longitudinal direction of the safety arrangement.

DETAILED DESCRIPTION

In figure 1 there is shown a schematic view of a vehicle 4 with a roof rack carrying a roof box 6, and wherein four security arrangements A according to the invention are arranged between the roof box 6 and the roof rack, i.e. two on the front roof rack bar and two on the rear roof rack bar, forming a load carrying assembly 5. It is foreseen that instead of two, merely one single unit may be used at the front and rear, respectively and indeed even merely one single unit for all of it.

The security arrangements A are adapted to secure e.g. a roof box 6 to e.g. a roof rack, forming a load carrying assembly 5. Generally, a security arrangement A may be seen as an attachment arrangement A for attaching a device for carrying a load by a vehicle 4, preferably attached to the roof or part of the roof of a vehicle 4, e.g. a roof rack attached to roof rails of the vehicle, wherein the security arrangement A is arranged between roof rack and a load 6 carried by the roof rack. However, it may also fulfil the same basic function in other applications. In figures 2 and 3 there are shown different perspective views of an embodiment of the security arrangement A according to the invention. The security arrangement A comprises a carrier plate 1, an attachment plate 2 and an energy absorbing member 3 in between the two plates 1,2. The plates 1,2 are interconnected by means of guiding members 11, 12, 20, 21 which enable the plates 1,2 to merely be moveable relative to each other in a longitudinal direction C, which longitudinal direction C coincides with the longitudinal direction of a vehicle, i.e. the direction of travel of the vehicle. This may mean that the guiding members 11, 12, 20, 21 may be arranged to enable relative movement, or relative displacement, between the carrier plate 1 and the attachment plate 2, e.g. solely parallelly with the longitudinal direction C. The carrier plate 1 is arranged with attachment devices 10 for attachment of the carrier plate 1 to a roof box, a rooftop cargo carrier or similar load carrying device. The attachment plate 2 is arranged with attachment devices 22 for attachment of the attachment plate 2 to a bar of a roof rack, which together forms an assembly 5 together with a load 6 on the roof rack. The energy absorbing member 3 that is arranged having a meandering shape, such as an S-shape, shape of digit eight or the like, in between the two plates 1,2 having a first attachment device 30,32 for attachment of one end thereof to the carrier plate 1 and a second attachment device 31, 33 for attachment thereof to the attachment plate 2.

The guiding members 11, 12, 20, 21 are in the form of two pairs of parallelly arranged ribs 11, 20, one pair on each of the plates 1,2 facing each other, thereby providing a gap G (see Fig 3) between the plates 1,2. Two of the ribs 11, 20, preferably one pair of the ribs 11 of one plate 1, are arranged with perpendicular protrusions 12 that fits in to corresponding recesses 21 in each of the ribs 11 of the other plate 1. In this manner opposing and parallel walls 11B, 20B of the ribs 11, 20 will prevent any relative movement between the plates 1 ,2 in a main plane of the security arrangement A and perpendicularly to the longitudinal direction C. Furthermore, the protrusions 12 and recesses 21 will prevent movement in a plane perpendicular to the main plane being parallel to second transversal direction relatively the longitudinal direction C.

Accordingly, relative movement of the plates 1 ,2 may merely occur in the longitudinal direction C. This means that the relative movement may for example solely occur in the longitudinal direction C, e.g. when the vehicle 4 decelerates.

Accordingly, the energy absorbing member 3 is in the form of a body, preferably specifically shaped to include curved portions that will be straightened by a force F acting in the longitudinal direction, that may be prolonged, and at least partially permanently deformed/prolonged, in connection with exercise of a force F onto the carrier plate 1 that exceeds a predetermined level. However, the security arrangement A (including a fully extended (or shortened) energy absorbing member 3), will be designed to withstand substantially higher forces, without any rupture, once the security arrangement A has absorbed the intended/predetermined maximal energy, i.e. after having relatively softly decelerated the load on the vehicle roof.

Preferably the shape of the energy absorbing member 3 is such that the relative movement between the plates 1,2 may only reach a maximal prolongation ALmax %=

100 x (Lmax- Lo) / Lo) of said absorbing member 3 from its nominal length Lo _, (e.g. 50- 150 mm) to a maximum length Lmax, wherein ALmax is at least 50%, preferably at least 100%, more preferred at least 150%. In the shown embodiment of Figs 2 and 3 the meandering/multi- S shaped energy absorbing member 3 may be prolonged from a nominal length Lo, e.g. of about 100 mm to a maximal prolongation AL _max of about 200 %, i.e. a maximum length L _ma x of about 300 mm. Further, as shown in Figs 2 and 3 the meandering/multi- S shaped energy absorbing member 3 may have a body shaped to have an increasing energy absorbing effect during prolongation, e.g. by means of having a continuously increasing cross-sectional area of the body, preferably by means of having an increasing width (t2>tl) from one end to the other. As a result, it will require a first level of force FI (e.g. above 1000 N, or more preferred above 1400 N) to straighten out the first bend having the smallest width tl, a higher a second level (e.g. + 10-30 %) of force F2 to straighten out the second bend having a larger width t2, etc. As an alternative to prolongation it is foreseen that the predetermined relative movement may instead comprise of said energy absorbing member 3, e.g. a maximal shortening of said absorbing member 3 from its nominal length Lo to a minimum (L _m in) that is at most 90%, preferably at most 50%. Also, in connection with shortening the energy absorbing member 3 may be designed to have an increasing energy absorbing effect during shortening. For example, such a body may be made of a metallic foam, wherein the foam structure is varied to achieve a progressive effect, or the foam structure is the same, but the shape is varied to achieve a progressive effect. In the preferred embodiment the main part of the energy absorbing member 3 is positioned between the two pairs of parallelly arranged ribs 11 , 20, in a longitudinal channel space formed between the pairs of ribs 11, 20. The height g of said channel space may be smaller than the gap G between said plates (1, 2).

In the preferred embodiment, shown in Fig 2 and 3 the attachment device 30,32 for attaching the energy absorbing member 3 to the carrier plate 1 is positioned besides the channel portion 1A of the carrier plate, i.e. in a side portion IB. As a consequence, a portion 34 of the energy absorbing member 3 will extend transversally from the side portion IB into the channel space. Hereby it is achieved that a longer (than if attached centrally) energy absorbing member 3 may be provided and that a surface 34A of that portion 34 may be arranged to abut an end surface 20A of one of said ribs 20, which may provide a definite stop of the carrier plate 1 , in the reverse, compressing direction, e.g. it may hinder the carrier plate 1 (with load, e.g. roof box) to move due to air resistance at high speed. Alternate embodiments to provide such a definite stop are foreseen, e.g. to use a break pin or similar device (not shown) that fixates the plates 1 ,2 relative each other up to a predetermined Force, F _break (e.g. 500 N), that is above the force acting on the load (e.g. roof box) due to air resistance.

Preferably the energy absorbing member 3 is made in a material and dimensions that makes is substantially stiff during normal use, implying that during normal use of an assembly according to the invention there will be no movement within the safety arrangement A. Hence no disturbing oscillations or movements that may cause disadvantages. However, in order to safeguard that no movement occurs during normal use the inventive concept may also comprise the use of a limit rupture device, e.g. break pin. The limit rupture function is such that it can resist forces up to a certain level/limit where after it breaks. One example of such a force limit rupture device may be in the form of a pin that is introduced into a through hole, e.g. a bore passing through both plates, preferably at a side edge, where they overlap. The pin will be of a material and have such a dimension that it breaks at a desired/predetermined level of force, where after the energy absorbing member 3 will start taking over the function to absorb energy.

In Fig. 4 there is shown a second embodiment of an energy absorbing member 3, wherein the shape is in the form of connected rings, e.g. oval shaped rings, that are connected centrally along the longitudinal lien C to each other, providing a symmetry line, such that during prolongation evenly distribution of forces in each ring half will occur. In figs 5, 6 and 7 there is shown a third embodiment of the invention, which may be suitable to use in an application relating to a load pulling assembly connected to a vehicle, wherein the security arrangement A according to the invention may eliminate a rupture of the coupling between the load pulling vehicle and the load that is pulled, e.g. in the form of a lorry arranged with a tow bar for a trailer. Preferably the load pulling assembly comprises a bar structure (not shown) that is securely fixed to the pulling vehicle, the security arrangement A being fixed with one part, e.g. the carrier plate 1, to the bar structure and the other part 2, e.g. the attachment plate 2, to the coupling member, e.g. tow ball, of the tow bar, such that energy may be absorbed by the energy absorbing member 3 if needed to avoid a sudden stop, possibly otherwise resulting in rupture of the tow bar.

It is foreseen that the security arrangement according to the invention may also be used for an assembly having a vehicle pushing a load wherein the security arrangement may eliminate rupture between a coupling between the pushing vehicle and the pushed load, e.g. a train pushing a wagon.

Further it is foreseen that in another application it may relate to a vehicle in the form of a moveable device in a machine which is arranged with a load stop assembly, wherein the security arrangement may eliminate rupture of the attachment between the ground and the stop member of the machine. It is evident for the skilled person that the invention is not limited to what is described above but may be varied within the scope of the claims. For instance, the skilled person realizes that there are many kinds of energy absorbing members 3, or energy absorbing withholding devices, that may be used to fulfil the basic function of the invention, e.g. foam like bodies, pistons (active or passive), etc and that compression may be used instead of prolongation. The energy absorbing member 3 may be made of a at least partially plastically formable material, such as a metal, a foam or the like. Further, it is evident that the basic function of the invention may also be fulfilled if the energy absorbing members 3 is positioned elsewhere than in between the plates 1,2. Preferably, the plates have a cross-sectional shape that allows using extrusion for production thereof, but of course various shapes are possible to fulfil the basic function of the invention. For instance, it is evident that the plates 1,2, need not be planar but may be curved, in various manners, e.g. to be more or less tubular. Hence, the expression plate must be given a broad interpretation. Moreover, it is foreseen that the carrier plate 1 may be positioned below the attachment plate 2, if using an upwardly extending roof rack where the load is positioned in a space between the roof rack bar and the roof of the vehicle. Moreover, it is evident that the basic principles of the invention may also be used in connection with other loads than on top of the roof of a vehicle and in connection with other vehicles than cars, e.g. load carrying assemblies 5 on a flat bed of a truck or rail wagon, etc.